BR112020021208B1 - VEHICLE VERTICAL TAKE-OFF AND LANDING SYSTEMS - Google Patents

Abstract

The systems and methods relate to a vertical takeoff and landing (VTOL) platform that may include a stator and a rotor magnetically levitated by the stator. The rotor and stator may be annular, such that the rotor rotates about an axis of rotation. The stator may include magnets that provide guidance, levitation, and actuation forces to drive the rotor, as well as to control the operation of rotor blades that can be independently rotated to specific pitch angles to control at least one of the VTOL platform's pitch, pitch, maneuver, or yaw. Multiple controllers may be used to allow independent and redundant control of components of the VTOL platform.

Description

REFERENCE TO RELATED APPLICATIONS

[0001] This disclosure claims the benefit of and priority to U.S. Provisional Application No. 62/659,013, entitled “SYSTEMS AND METHODS FOR VERTICAL TAKEOFF AND LANDING WITH MAGNETIC PROPULSION,” filed April 17, 2018, and U.S. Provisional Application No. 62/775,253, entitled “MAGNETIC LEVITATION FOR VERTICAL TAKEOFF AND LANDING,” filed December 4, 2018, the disclosures of which are incorporated herein by reference in their entirety.

TECHNICAL FIELD

[0002] The present disclosure relates generally to vertical takeoff and landing. More particularly, the present disclosure relates to a magnetic bearing for vertical takeoff and landing.

STATE OF THE TECHNIQUE

[0003] Various airborne platforms can perform vertical takeoff and landing (VTOL), in which the platforms can hover, take off, and land vertically. VTOL platforms can include fixed-wing platforms and rotary-wing platforms. VTOL platforms can include unmanned aerial vehicles. VTOL platforms can have distributed electric propulsion and can have tilt-rotor and/or tilt-wing configurations.

[0004] VTOL platforms typically rely on combustion-based power generation to generate lift and other motion forces. Additionally, VTOL platforms can be relatively large. As such, existing VTOL platforms may have technical limitations that make them difficult to use in urban environments and personal use modes.

SUMMARY

[0005] At least one aspect of the present disclosure relates to a VTOL platform. The VTOL platform includes a rotor, a stator, a flight controller, and a motor controller. The rotor includes a plurality of rotor blades oriented about a rotor axis and radially spaced from the stator. Each rotor blade is coupled to a rotor arm such that rotation of the rotor arm causes the rotor blade to rotate about a rotor pitch axis. The rotor arm is coupled to a first rotor magnet spaced from a second rotor magnet. The stator includes a plurality of electromagnets. The flight controller is configured to receive a motion instruction, extract a desired motion from the motion instruction, and generate one or more flight commands configured to cause the rotor to generate at least one of thrust, a moment force about a yaw axis, a moment force about a platform pitch axis, or a moment force about a roll axis. The motor controller is configured to receive one or more flight control commands and actuate electrical signals through the electromagnets based on the one or more flight control commands. The plurality of electromagnets are configured to emit electromagnetic fields corresponding to the electrical signals to actuate the rotor magnets of the rotor to rotate the rotor about the rotor axis, rotate the rotor blade about the blade's neutral pitch axis, and cause the rotor to generate at least one of thrust, a moment about the yaw axis, a moment about the platform pitch axis, or a moment about the platform roll axis.

[0006] At least one aspect of the present disclosure relates to a rotor for operation with a stator. The rotor includes an annular rotor base defining an axis of rotation and comprising a plurality of rotor segments disposed about the stator. Each rotor segment includes a sidewall spaced from the axis of rotation, a first rotor wall extending from a first end of the sidewall and toward the axis of rotation, and a second rotor wall extending from a second end of the sidewall and toward the axis of rotation, the second rotor wall spaced from the first rotor wall, the rotor defining a rotor axis through the first rotor wall and the second rotor wall and parallel to the axis of rotation. Each rotor segment includes at least a first rotor magnet coupled to the first rotor wall, the at least one first rotor magnet configured to maintain a first space between the first rotor wall and a first stator magnet along the rotor axis. Each rotor segment includes at least one second rotor magnet coupled to the second rotor wall, the at least one second rotor magnet configured to maintain a second space between the second rotor wall and a second stator magnet along the rotor axis. Each rotor segment includes at least one third rotor magnet coupled to the side wall and spaced from one or more stator drive magnets. The rotor is configured to be driven by the drive magnets at a rotational speed via the magnetic field of the one or more drive magnets interacting with the at least one third rotor magnet.

[0007] At least one aspect relates to a stator for operation with a rotor. The stator includes an annular stator base comprising a plurality of stator segments, the stator base defining a central axis. Each stator segment includes a sidewall, a support structure extending from the sidewall, at least one first stator magnet coupled to a first surface of the support structure, at least one second stator magnet coupled to a second surface of the support structure opposite the first surface, and at least one drive magnet. The at least one first stator magnet and the at least one second stator magnet defining a stator axis parallel to the central axis, the at least one first stator magnet configured to maintain a first space between a first rotor magnet of the rotor and the at least one first stator magnet along the stator axis, and the at least one second stator magnet configured to maintain a second space between a second rotor magnet of the rotor and the at least one second stator magnet along the stator axis. The at least one drive magnet is coupled to the support structure and spaced from one or more third rotor magnets of the rotor, the at least one drive magnet configured to emit a magnetic field responsive to a control signal to drive the rotor about the central axis.

[0008] At least one aspect relates to a rotor control system. The rotor control system includes a rotor and a stator. The rotor includes a first rotor magnetic component aligned with one or more first stator coils, a second rotor magnetic component aligned with one or more second stator coils and adjacent to the first rotor magnetic component, an arm connecting the first rotor magnetic component and the second rotor magnetic component, and a first rotor blade attached to the arm, a first arm end of the arm coupled to the first rotor magnetic component, and a second arm end of the arm coupled to the second rotor magnetic component defining an arm angle that changes based on a first magnetic force applied to the first rotor magnetic component relative to a second magnetic force applied to the second rotor magnetic component. The first rotor blade extending from the arm along a blade pitch axis, the first rotor blade defining a blade pitch angle relative to the blade pitch axis, the blade pitch angle corresponding to the arm angle. The stator includes a plurality of electromagnets configured to emit at least a first magnetic field that drives the first magnetic component of the rotor and a second magnetic field that drives the second magnetic component of the rotor, responsive to at least one control signal, the at least one control signal causing the first magnetic field to apply the first magnetic force to the first magnetic component of the rotor and the second magnetic field to apply the second magnetic force to the second magnetic component to control the blade pitch angle.

[0009] At least one aspect relates to a rotor control system. The rotor control system includes a rotor and a stator. The rotor includes an annular rotor base defining an axis of rotation and comprising a plurality of rotor segments disposed about the stator. Each rotor segment includes a first rotor blade configured to be rotated about a blade pitch axis perpendicular to the axis of rotation, a power receiver circuit, a motor that rotates using power received through the power receiver circuit to rotate the first rotor blade about the blade pitch axis, a motor controller that provides a motor signal to the motor to rotate the first rotor blade about the blade pitch axis responsive to a control signal, and a first wireless transceiver that receives the control signal and provides the control signal to the motor controller. The stator includes a second wireless transceiver that receives a control command and wirelessly transmits the control signal to the first wireless transceiver based on the control command, and a power transmitter circuit that emits a magnetic field that interacts with the power receiver circuit to provide power to the power receiver circuit.

[0010] At least one aspect relates to a system. The system includes a rotor and a stator. The rotor includes a sidewall, a first rotor wall extending from a first end of the sidewall and a second rotor wall extending from a second end of the sidewall, the second rotor wall spaced from the first rotor wall, at least one first rotor magnet coupled with the first rotor wall, and at least one second rotor magnet coupled with the second rotor wall. The stator includes a support structure extending between the first rotor wall and the second rotor wall, at least one first stator magnet coupled with a first surface of the support structure and proximate to the at least one first rotor magnet, the at least one first rotor magnet inducing a current in the at least one first stator magnet corresponding to a first distance between the at least one first stator magnet and the at least one first rotor magnet, and at least one second stator magnet coupled with a second surface of the support structure opposite the first surface and proximate to the at least one second rotor magnet, the at least one second stator magnet electrically coupled with the at least one first stator magnet for receiving current from the first stator magnet, the at least one second stator magnet emitting a magnetic field having a magnetic field strength based on the current in the first stator magnet, the magnetic field interacting with the at least one second rotor magnet to control a second distance between the at least one second stator magnet and the at least one second rotor magnet. stator and at least one second rotor magnet.

[0011] At least one aspect relates to a system. The system includes a rotor and a stator. The rotor includes a sidewall, a rotor wall extending from an end of the sidewall, and at least one rotor magnet coupled to the rotor wall. The stator includes a support structure adjacent to the rotor wall, a first stator magnet coupled to a surface of the support structure proximate to the at least one rotor magnet, the at least one rotor magnet inducing a current in the first stator magnet corresponding to a first magnetic force of a first magnetic field between the first stator magnet and the at least one rotor magnet, and a second stator magnet coupled to the surface of the support structure, the second stator magnet electrically coupled to the first stator magnet, the second stator magnet receiving current from the first stator magnet to control a second magnetic force of a second magnetic field between the second stator magnet and the at least one rotor magnet.

[0012] At least one aspect relates to a system. The system includes a rotor and a stator. The rotor includes a rotor sidewall defining an axis of rotation, at least one rotor blade coupled transverse to the sidewall along a first surface of the sidewall, and a rotor magnet coupled to the sidewall along a second surface of the rotor sidewall opposite the first surface. The stator includes a plurality of stator magnets disposed circumferentially along a surface of a stator sidewall facing the second surface of the rotor sidewall, and a wireless controller coupled to the plurality of stator magnets, the controller controlling the plurality of stator magnets to selectively produce a respective magnetic field interacting with the rotor magnet of the rotor to rotate the rotor and rotor blade about the axis of rotation to produce lift along the axis of rotation.

[0013] At least one aspect relates to a system. The system includes a rotor and a stator. The rotor includes a rotor sidewall defining an axis of rotation, at least one rotor blade coupled transversely to the sidewall along a first surface of the sidewall, and a rotor magnet coupled to the sidewall along a second surface of the rotor sidewall opposite the first surface. The stator includes a plurality of stator magnets disposed circumferentially along a surface of a stator sidewall facing the second surface of the rotor sidewall, and a controller electrically coupled to the plurality of stator magnets, the controller controlling the plurality of stator magnets at a switching rate to selectively produce a respective magnetic field, the magnetic fields interacting with the rotor magnet of the rotor to rotate the rotor and rotor blade at a rotational speed corresponding to the switching rate to produce lift at a lifting speed.

[0014] At least one aspect relates to a system. The system includes a rotor configured to rotate about a rotation axis and a stator. The rotor includes a rotor sidewall, at least one rotor blade rotatably coupled with the sidewall along a first surface of the sidewall, the at least one rotor blade rotating about a blade axis extending transversely to the sidewall, and a first rotor magnet and a second rotor magnet coupled to the sidewall along a second surface of the rotor sidewall opposite the first surface. The stator includes a plurality of first stator magnets arranged circumferentially along a sidewall of the stator facing the sidewall of the rotor, at least one of the plurality of first stator magnets proximate to the first rotor magnet, a plurality of second stator magnets spaced apart from respective first stator magnets and circumferentially arranged along the sidewall of the stator, at least one of the plurality of second stator magnets proximate to the second rotor magnet, and a magnet controller electrically coupled to the plurality of first stator magnets and the plurality of second stator magnets, the magnet controller controlling the plurality of first stator magnets at a first switching rate and controlling the plurality of second stator magnets at a second switching rate to produce rotation of the rotor blade about the blade axis.

[0015] At least one aspect relates to a system. The system includes a stator and a rotor. The stator includes a plurality of stator magnets arranged circumferentially along a surface of the stator. The rotor is configured to rotate about an axis of rotation and has an annular rotor base surrounding the stator. The rotor includes a plurality of rotor segments. Each rotor segment includes a sidewall spaced from the axis of rotation having a first surface and a second surface opposite the first surface, at least one rotor magnet coupled to the sidewall along the first surface, the rotor configured to be driven by the plurality of stator magnets through respective magnetic fields of the plurality of stator magnets interacting with the at least one rotor magnet, and at least one rotor blade having a first blade end coupled with the second surface of the sidewall and a second blade end, the first end and second defining a rotor blade length, the second end and axis of rotation defining a radius of rotation, a ratio of the rotor blade length to the tip radius of rotation being less than or equal to 0.75.

[0016] At least one aspect relates to a system. The system includes a rotor configured to rotate about a rotation axis and a stator. The rotor includes a rotor sidewall, a first rotor blade rotatably coupled to the sidewall along a first surface of the sidewall, the first rotor blade rotatably coupled about a first blade axis extending transversely to the sidewall, a second rotor blade rotatably coupled to the sidewall along the first surface of the sidewall, the second rotor blade rotatably coupled about a second blade axis extending transversely to the sidewall, a first set of rotor magnets including a first rotor magnet and a second rotor magnet coupled to the sidewall along a second surface of the rotor sidewall opposite the first surface proximate to the first rotor blade, and a second set of rotor magnets including a third rotor magnet and a fourth rotor magnet coupled to the sidewall along the second surface of the rotor sidewall proximate to the second rotor blade. The stator includes a plurality of first stator magnets disposed circumferentially along a stator sidewall facing the rotor sidewall, at least one of the plurality of first stator magnets proximate to the first rotor magnet and at least one of the plurality of first stator magnets proximate to the third rotor magnet, a plurality of second stator magnets spaced apart from respective first stator magnets and circumferentially disposed along the stator sidewall, at least one of the plurality of second stator magnets proximate to the second rotor magnet and at least one of the plurality of second stator magnets proximate to the fourth rotor magnet, and at least one controller electrically coupled to the plurality of first stator magnets and the plurality of second stator magnets, the at least one controller configured to receive a motion instruction, extract a desired motion from the motion instruction, generate a plurality of control signals based on the desired motion, and provide the plurality of control signals to the plurality of first stator magnets. and the plurality of second stator magnets for causing the plurality of first stator magnets and the plurality of second stator magnets to generate magnetic fields corresponding to the plurality of control signals that drive the rotor magnets of the rotor to rotate the rotor about the rotation axis, rotate the first rotor blade about the first blade axis, and rotate the second rotor blade about the second blade axis to produce the desired motion.

[0017] At least one aspect relates to a rotor for operation with a stator. The rotor includes an annular rotor base defining an axis of rotation and comprising a plurality of first rotor segments disposed about the stator and configured to be driven in a first direction about the axis of rotation and a plurality of second rotor segments disposed about the stator adjacent to the plurality of first rotor segments and configured to be driven in a second direction about the axis of rotation opposite the first direction, each rotor segment including a sidewall spaced from the axis of rotation, a first rotor wall extending from a first end of the sidewall and toward the axis of rotation, and a second rotor wall extending from a second end of the sidewall and toward the axis of rotation, the second rotor wall spaced from the first rotor wall, the rotor defining a rotor axis through the first rotor wall and the second rotor wall and parallel to the axis of rotation, at least one first rotor magnet coupled to the first rotor wall, the at least one first rotor magnet configured to maintain a first space between the first rotor wall and the first rotor magnet. stator along the rotor axis, at least one second rotor magnet coupled with the second rotor wall, the at least one second rotor magnet configured to maintain a second space between the second rotor wall and the second rotor magnet along the rotor axis, at least a third rotor magnet coupled to the side wall and spaced from one or more drive magnets of the stator, the rotor configured to be driven by the drive magnets via a magnetic field of the one or more drive magnets interacting with the at least one third rotor magnet. In some embodiments, the at least one rotor blade is a first rotor blade and the rotor magnet is a first rotor magnet corresponding to the first rotor blade, the first rotor blade configured to rotate about the axis of rotation in a first direction, and the rotor includes a second rotor blade spaced from the first rotor blade, the second rotor blade coupled and transverse to the sidewall along a first surface of the sidewall, and a second rotor magnet corresponding to the second rotor blade, the second rotor magnet being driven to drive the second rotor blade in a second direction about the axis of rotation opposite the first direction.

[0018] Those skilled in the art will appreciate that the summary is illustrative only and is not intended to be limiting in any way. Other aspects, inventive features, and advantages of the devices and/or processes described herein, as defined solely by the claims, will become apparent from the detailed description presented herein and considered in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The foregoing and other objects, aspects, features and advantages of the disclosure will become more apparent and better understood by reference to the following description taken in conjunction with the accompanying figures, in which:

[0020] FIG. 1 is a schematic diagram of one embodiment of a VTOL platform.

[0021] FIG. 2 is a schematic diagram of a portion of the VTOL platform of FIG. 1.

[0022] FIG. 3 is a block diagram of various systems of the VTOL platform of FIG. 1.

[0023] FIG. 4 is a partial perspective view of an engine region of the VTOL platform of FIG. 1.

[0024] FIG. 5 is a sectional view of the engine region of the VTOL platform of FIG. 1.

[0025] FIG. 6 is a schematic diagram of one embodiment of magnetic bearing functionality and orientation systems.

[0026] FIG. 7 is a block diagram of one embodiment of a flight dynamics system of a VTOL platform.

[0027] FIG. 8 is a schematic diagram of collective pitch control executed by the flight dynamics system of FIG. 7.

[0028] FIG. 9 is a schematic diagram of cyclic pitch control executed by the flight dynamics system of FIG. 7.

[0029] FIG. 10 is a block diagram of one embodiment of a motor controller of a VTOL platform.

[0030] FIG. 11 is a block diagram of one embodiment of a stator of a VTOL platform.

[0031] FIG. 12 is a block diagram of a rotor control system of a VTOL platform.

[0032] FIG. 13 is a flow diagram of one embodiment of a method of controlling a VTOL platform.

[0033] FIG. 14A is a schematic diagram of one embodiment of a rotor with motor-driven rotor blades.

[0034] FIG. 14B is a block diagram of one embodiment of a rotor control system using motor-driven rotor blades.

DETAILED DESCRIPTION

[0035] For purposes of reading the description of the various embodiments below, the following enumeration of the sections of the specification and their respective contents may be helpful:- Section A describes embodiments of systems and methods of a VTOL platform that operates using magnetic bearing functionality;- Section B describes embodiments of systems and methods of guiding and guiding a VTOL platform that operates using magnetic bearing functionality; and- Section C describes embodiments of systems and methods of controlling a VTOL platform that operates using magnetic bearing functionality, including flight dynamics, motor control, and pitch control. A. Systems and Methods of VTOL Platforms Using Magnetic Bearing Functionality

[0036] Referring generally to FIGS. 1-5, a VTOL platform according to the present disclosure may use magnetic bearing functionality and specific control mechanisms to efficiently drive a rotor with a stator to enable vertical takeoff and landing, as well as flight control operations such as pitch, pitch, roll, and yaw control. The VTOL platform may have improved size, weight, power, and cost (SWAP-C) factors over existing systems, including increased power density over internal combustion-based systems. The VTOL platform may achieve high rotor rotation rates for an annular platform configuration.

[0037] The VTOL platform may have reduced noise compared to existing systems with similar performance capabilities by reducing the generation of mechanical and aerodynamic noise. Existing systems that rely on the mechanical operation of gearboxes, swash plates, and generators can generate significant noise. In turbines, mechanical noise can be transmitted along the turbine structure and radiated from its surfaces, and aerodynamic noise can be produced by the airflow over the blades. In helicopters, noise can be generated by the interactions of the main rotor and tail rotor with the air. This can be verified by analyzing the frequency spectrum of a helicopter during takeoff: there may be global and local maxima at the respective blade-pass frequencies of each rotor blade. There may also be a very broad distribution of acoustic power sweeping through the higher frequencies, and this broadband noise may result from a combination of several noise mechanisms, including the operation of the turbine, gearbox, and transmission. This solution can address these noise sources by using a direct electric drivetrain that relies on fewer interactions between mechanical components and by configuring the rotor blades in a way that reduces noise generation. Thus, this solution can reduce the energy inefficiencies associated with noise generation, as well as the noise-related annoyances that make existing systems less viable for urban environments and personal use.

[0038] In some embodiments, the VTOL platform includes a rotor, a stator, a flight controller, and a motor controller. The rotor includes a plurality of rotor blades oriented about a rotor axis and radially spaced from the stator. Each rotor blade is coupled to a rotor arm such that rotation of the rotor arm causes the rotor blade to rotate about a rotor pitch axis. The rotor arm is coupled to a first rotor magnet spaced from a second rotor magnet. The stator includes a plurality of electromagnets. The flight controller is configured to receive a motion instruction, extract a desired motion from the motion instruction, and generate one or more flight commands configured to cause the rotor to generate at least one of thrust, a moment force about a yaw axis, a moment force about a platform pitch axis, or a moment force about a platform roll axis. The motor controller is configured to receive one or more flight control commands and actuate electrical signals through the electromagnets based on the one or more flight control commands. The plurality of electromagnets are configured to emit electromagnetic fields corresponding to the electrical signals to actuate the rotor magnets of the rotor to rotate the rotor about the rotor axis, rotate the rotor blade about the blade's neutral pitch axis, and cause the rotor to generate at least one of thrust, a moment about the yaw axis, a moment about the platform pitch axis, or a moment about the platform roll axis.

[0039] Referring now to FIGS. 1-2, a VTOL platform 100 includes a stator 110 that drives a rotor 120. The rotor 120 may extend from the stator 110 into a compartment 130 (e.g., a nacelle). A support structure 140 may be mounted to the stator 110 so as to provide a seat 142 for an operator 144 of the VTOL platform 100. Although FIGS. 1-2 illustrate stator 110 into rotor 120, stator 110 may be outward from rotor 120. Rotor 120 may be supported by a magnetic bearing system (e.g., magnetic bearing system 360 described with reference to FIG. 3) coupled to stator 110 for rotation about stator 110. Stator 110 and rotor 120 may include various magnets (e.g., permanent magnets; electromagnetic coils; electromagnetic coils through which current may be conducted to cause the electromagnetic coils to generate magnetic fields).

[0040] Stator 110 may use power from a power source 112 to drive rotor 120 by emitting electromagnetic fields to drive magnets of rotor 120, including to rotate rotor 120 about a rotation axis 122. For example, stator 110 may drive rotor 120 based on control signals received from a controller, as discussed later in this document. Power source 112 may include one or more batteries. Power source 112 may be highly distributed and integrated into support structure 140, which may improve rigidity and reduce weight of VTOL platform 100 compared to existing systems.

[0041] Stator 110 may have greater efficiency than existing mechanical systems. The use of an electromagnetic coupling between stator 110 and rotor 120, rather than mechanical connections, may improve operation over existing systems. In order to achieve a VTOL platform with performance parameters similar to those enabled by the present solution in existing systems, the motor would need to drive small gears rotating much faster than a large-radius rotor, which could result in significant mechanical friction losses, and weigh significantly more than a simple rotor mounted on a driven shaft. In such existing systems, there may be large efficiency losses due to the extreme gear ratio, great inherent manufacturing difficulties of the large toothed and/or geared ring structures, noisy mechanical interactions that outweigh any aeroacoustic benefits of the annular rotor geometry, and/or large, heavy structures used for power transfer that can significantly increase the overall weight. The present solution can address such phenomena by using the stator 110 to drive the rotor 120 - in some embodiments, the present solution can produce distributed torque through the use of a high-power, efficient, and responsive electric synchronous motor, rather than a gearbox or shaft for torque transfer as the rotor ring, and can simultaneously act as the electromechanical rotor, the drive shaft, and the blade hub, thereby reducing weight, efficiency losses, and mechanical complexity.

[0042] Furthermore, with respect to stator 110 and rotor 120, it has been found that the power density of the motor increases linearly with hub radius and decreases linearly with motor height. The present solution may implement such features to configure stator 110 to have a relatively large radius and relatively low thickness to increase efficiency and power density, allowing stator 110 to have less mass and/or higher power output relative to existing internal combustion-based systems.

[0043] Rotor 120 is shown as an annular rotor that can orbit about stator 110 and support structure 140. Rotor 120 includes a plurality of first blades 124 (coupled to respective magnets, as discussed later herein). The plurality of first blades 124 can extend between stator 110 and housing 130. In some embodiments, stator 110 controls a pitch angle of each first blade 124. First blades 124 can be coupled to and transverse to (e.g., perpendicular to) sidewall 134. As illustrated in FIGS. 1 and 4, each first blade 124 may extend from a first blade end (e.g., blade root) 444 coupled with sidewall 134 (e.g., rotor segments 132 of sidewall 134) to a second blade end (e.g., blade tip) 448, which may be coupled to housing 130 or free of housing 130. First blade 124 may define a blade axis 440 extending from the first blade end 444 to the second blade end, which may be perpendicular to rotation axis 122.

[0044] In some embodiments, the rotor 120 includes a plurality of second blades 126, which may be similar to the first blades 124 and may rotate about the axis of rotation 122 independently of the plurality of first blades 124. The second blades 126 may be spaced apart from the first blades 124, such as being coupled to the sidewall 134 (e.g., rotor segments 132 of the sidewall 134) below the first blades 124 or coupled to a second sidewall 134 below the first blades 124.

[0045] By rotating the first blades 124 and/or the second blades 126, the VTOL platform 100 may generate lift due to the action of the first blades 124 and/or the second blades 126 on the air passing through the VTOL platform 100. Likewise, the first blades 124 and/or the second blades 126 may be actuated in a manner that causes rotation about the yaw, roll, and/or pitch axes.

[0046] The rotor blades 124, 126 may be individually feathered (e.g., blade surfaces aligned at a particular angle relative to the airflow direction) to maintain cyclic and collective pitch commands for orientation of the VTOL platform 100. Compared to existing systems, in which a swash plate may be used to control the operation of the rotor blades, the present solution may individually control the pitch of each rotor blade 124, 126 in a frictionless manner.

Systems and methods for controlling lift using counter-rotating rotors

[0047] In some embodiments, the plurality of first blades 124 rotate in a first direction about the axis of rotation 122, while the plurality of second blades 126 rotate in a second direction about the axis of rotation 122 opposite the first direction. As such, the plurality of first blades 124 and the plurality of second blades 126 may be counter-rotating. For example, each second blade 126 may be coupled to respective rotor magnets 380 that are driven by the stator 110 in the second direction. As discussed further herein, the control circuit 310 may control the operation of the plurality of first blades 124 by providing a first control signal to cause the plurality of first blades 124 to rotate about the rotation axis 122 in the first direction at a first angular rate, and control the operation of the plurality of second blades 126 by providing a second control signal to cause the plurality of second blades 126 to rotate about the rotation axis 122 in the second direction at a second angular rate. The control circuit 310 may generate the first control signal and the second control signal to generate a desired motion of the VTOL platform 100. For example, to allow the VTOL platform 100 to operate in a hover mode, the control circuit 310 may generate the first control signal and the second control signal such that the first angular rate and the second angular rate are configured such that a force balance on the VTOL platform 100 is zero in at least one vertical direction (e.g., the upward force generated by the plurality of first blades 124 counteracts gravity and the downward force generated by the plurality of second blades 126).

Systems and methods for reducing noise based on the effective area of the rotor relative to a center of rotation

[0048] In some embodiments, the rotor blades 124, 126 are configured to allow for a relatively lower acoustic profile, such as to generate reduced noise while generating sufficient lift to support the movement of the VTOL platform 100. In the present solution, the number of rotor blades 124, 126 may be selected to be relatively high, with the blades having phase-modulated spacing, to reduce noise while maintaining lift. Each blade 124, 126 may have a relatively large tip diameter. The rotor blades 124, 126 may be positioned and aligned relative to each other to operate incoherently. As such, noise resulting from the interaction of the rotor 120 and surrounding fluid may be reduced. In some embodiments, the rotor blades 124, 126 have a maximum tip Mach number of 0.5 and a floating tip Mach number of 0.41. In some embodiments, rotor blades 124, 126 are at least one ducted or shielded, which can increase lift generation, improve safety, and reduce noise radiated from rotor blades 124, 126. In some embodiments, housing 130 is shaped to reflect noise upward and can also attenuate noise traveling outward from rotor 120.

[0049] In some embodiments, rotor blades 124, 126 have a relatively short length relative to a radius of rotation of second blade end 448. For example, rotor blades 124, 126 may define a rotor blade length from first blade end 444 to second blade end 448 along blade axis 440 (e.g., from blade root to blade tip). Second blade end 448 may define a radius of rotation from second blade end 448 to axis of rotation 122. Rotor blades 124, 126 may define a ratio of rotor blade length to radius of rotation. In some embodiments, the ratio is less than or equal to 0.75. In some embodiments, the ratio is less than or equal to 0.6 and greater than or equal to 0.3. For example, as illustrated in FIG. 2, rotor blades 124, 126 start outward from the axis of rotation 122. In some embodiments, the efficiency of a rotor blade in generating lift as a function of distance from a center of rotation (e.g., from the axis of rotation 122) is generally greater toward the blade tip than toward the blade root. As such, the present solution can reduce noise with relatively less loss of performance by selecting blades that operate primarily in the high-efficiency region.

[0050] In some embodiments, rotor blades 124, 126 have a relatively high effective blade area or blade solidity. The second blade end 448 may define a first perimeter (e.g., a perimeter swept by the second blade end 448 when the second blade end 448 rotates about the rotation axis 122). The sidewall 134 (or the first blade end 444) may define a second perimeter, which is within the first perimeter. Rotor blades 124 and/or 126 may also define a blade rotation area in a first plane between the first perimeter and the second perimeter (e.g., a first plane in which the first perimeter and the second perimeter meet). The blade rotation area may represent the area swept by the first rotor blade 124 in the foreground when the first rotor blade 124 rotates about the rotation axis 122. The rotor blades 124 and/or the rotor blades 126 may define a blade surface area in the foreground, which may represent a surface area of the rotor blades 124 and/or the rotor blades 126 that are in the foreground (while the rotor blades 124 or the rotor blades 126 are stable or not moving). The plurality of first rotor blades 124 (or the plurality of second rotor blades 126) may define an effective blade area as a ratio of the blade surface area to the blade rotation area. In some embodiments, the effective blade area is greater than or equal to 0.4 (e.g., compared to 0.2 in many existing systems). In some embodiments, the effective blade area is greater than or equal to 0.6. By having an increased effective blade area, rotor blades 124, 126 can more efficiently generate lift at lower speeds and pitches; VTOL platform 100 can achieve larger effective blade areas using frictionless methods to drive the rotation of rotor 120, which would otherwise not be possible using mechanical couplings, such as swash plates and gearboxes, to rotate rotor 120 (or would result in increased mechanical noise that would offset the noise reductions from the increased effective blade area).

[0051] The VTOL platform 100 may include a plurality of beams 150 extending from the support structure 140 to the compartment 130. The beams 150 may be unidirectional carbon fiber spokes. The beams 150 may be swept and tilted to increase a number of incident wakes from the rotor blades 124, 126 acting on each beam 150, spreading the phase angle of the wakes to achieve decoherence. The beams 150 may provide radial, vertical, and torsional stiffness to hold the compartment 130 secure relative to the support structure 140.

[0052] Referring now to FIGS. 3-5, a VTOL system 300 includes a control circuit 310, stator 110, and rotor 120. VTOL system 300 may be implemented to control the operation of the VTOL platform 100 described with reference to FIGS. 1-2. Control circuit 310 includes a processor 312 and memory 314. Processor 312 may be implemented as a special-purpose processor, an application-specific integrated circuit (ASIC), one or more field-programmable gate arrays (FPGAs), a group of processing components, or other suitable electronic processing components. Processor 312 may be a distributed computing system or a multi-core processor. Memory 314 is one or more devices (e.g., RAM, ROM, flash memory, hard disk storage) for storing data and computer code to complete and facilitate the various user or client processes, layers, and modules described in this disclosure. Memory 314 may be or include volatile memory or non-volatile memory, and may include database components, object code components, scripting components, or any other type of information structure to support the various activities and information structures of the inventive concepts disclosed herein. Memory 314 is communicably connected to processor 312 and includes computer code or instruction modules for executing one or more processes described herein. Memory 314 may include various circuits, software engines, and/or modules that enable the processor to execute the systems and methods described herein. Memory may be distributed among distinct devices.

[0053] Memory 314 includes a flight controller 316 and a motor controller 318. Flight controller 316 may use flight dynamics models, rotor state, and control laws to convert the desired motion of VTOL system 300 into flight control signals 320 and transmit the flight control signals 320 to motor controller 318. Motor controller 318 may receive the flight control signals 320 and generate motor control signals 322 based on the flight control signals 320 to control the operation of stator 110 to cause VTOL platform 100 to achieve the desired motion.

[0054] The VTOL system 300 may include a communications circuit 330. The communications circuit 330 is configured to receive and transmit data. The communications circuit 330 may include receiver electronics and transmitter electronics. The communications circuit 330 may include a radio configured for radio frequency communication. The communications circuit 330 may include a data link radio. The communications circuit 330 may receive and transmit navigation information to/from remote platforms.

[0055] The VTOL system 300 may include at least one sensor 334. The at least one sensor 334 may provide sensor data to the control circuit 310. The at least one sensor 334 may detect position, velocity, acceleration, altitude, orientation, and other state parameters of the VTOL system 300 (e.g., of the VTOL platform 100 implementing the VTOL system 300). The at least one sensor 334 may detect environmental parameters such as temperature, air pressure, and wind speed. The at least one sensor 334 may include at least one of an inertial measurement unit (which may include one or more gyroscopes and one or more accelerometers, such as three gyroscopes and three accelerometers), an air data sensor (e.g., sensor(s) configured to detect and output an indication of static pressure), or a magnetic compass. The at least one sensor 334 may include a global navigation satellite system (GNSS) receiver and/or a global positioning system (GPS) receiver.

[0056] The VTOL system 300 may include a user interface 340 including a display device 342 and a user input device 344. The display device 342 may receive display data from the control circuit 310 and present the received display data. The display device 342 may include various display components, including but not limited to CRT, LCD, organic LED, dot matrix display, and others. The display device 342 may include navigation displays, primary flight displays, electronic flight case displays, tablets such as iPad® computers manufactured by Apple, Inc. or tablet computers, synthetic vision system displays, HUDs with or without a projector, forward guidance systems, wearable displays, watches, Google Glass®, or other HWD systems. The display device 342 may present display data such as air traffic control data, weather data, navigation data (e.g., flight plans), and terrain information.

[0057] User input device 344 may include, for example, displays, switches, buttons, touchscreens, keyboards, a mouse, joysticks, cursor control devices (CCDs). User input device 344 may include a touch interface provided by one or more components of display device 342. User input device 344 may include an audio input device configured to receive audio information (e.g., spoken information from an operator) that control circuit 310 may process. User input device 344 may include an image capture device, such that control circuit 310 may perform image processing functions such as gesture control, head tracking, and/or eye tracking, and generate control instructions based on the image processing.

[0058] The user interface 340 may receive a user input and transmit an indication of the user input 346 to the flight controller 316. The flight controller 316 may receive the indication of the user input 346, extract an input command from the indication of the user input 346, and determine a desired movement of the VTOL platform 100 based on the input command in order to generate the flight control signals 320.

Improved stator assembly for use with a rotor

[0059] The stator 110 includes a stator compartment 350 (e.g., an annular stator base) supporting a plurality of stator magnets 352 (e.g., drive magnets). The stator compartment 350 may include a plurality of stator segments 351, which may be contiguous, such as being integral or monolithic, or may be at least partially disconnected, such as being separate members or being connected by extensions that are narrower than adjacent stator segments 351. The plurality of stator magnets 352 may each be driven by motor control signals 322. The plurality of stator magnets 352 may be electromagnets. For example, the plurality of stator magnets 352 may include electromagnetic coils that emit electromagnetic fields based on electrical signals driven through the electromagnetic coils. Electromagnetic coils may be made of various conductive materials, including aluminum or copper. In some embodiments, aluminum may be used based on its lightweight, high thermal conductivity, and electrical conductivity more than twice that of copper on a mass-to-mass basis (e.g., aluminum may be selected that has 61 percent of the conductivity of copper but 30 percent of the mass of copper for a given volume, allowing mass savings to be offset by increased volume to achieve the same ampere rating). Stator 110 may include a laminated iron core 504 adjacent to stator magnets 352, which may increase the magnitude of the magnetic field emitted by stator magnets 352.

[0060] In response to receiving a particular motor control signal 322, each stator magnet 352 may produce a corresponding electromagnetic field 354. Each stator magnet 352 may vary a magnitude of the emitted electromagnetic field 354 as a function of time, depending on the received motor control signal 322. For example, if the motor control signal 322 has varying values of parameters such as amplitude and frequency, the amplitude and frequency of the electromagnetic field 354 may vary similarly.

[0061] As further described herein, stator 110 may include magnets 362a, 362b, 364a, and 364b of LGS 360 that may interact with rotor magnets 372, 374 to maintain respective gaps between stator 110 and rotor 120 and, in turn, receive lift from rotor 120 to lift stator 110. For example, as stator magnets 352 emit electromagnetic fields 354, the lift generated by rotation of rotor 120 may cause rotor 120 to move upward (e.g., closer to magnet 372 and further from magnet 374); As a result, rotor 120 applies force through magnets 372, 374 to stator 110, lifting stator 110 as the operation of magnets 362a, 362b, 364a, and 364b adjust to the forces applied by rotor 120 and transfer the forces to stator housing 350.

Improved rotor assembly for use with a stator

[0062] Rotor 120 includes a rotor base 128. Rotor base 128 may be annular, extending about axis of rotation 122 and defining a space between rotor base 128 and stator housing 350. Rotor base 128 may include a plurality of rotor segments 132. Each rotor segment 132 may include a sidewall 134 spaced from axis of rotation 122. Rotor segments 132 may be contiguous, such as each rotor segment 132 being connected to adjacent rotor segments 132 or being integral or monolithic. Rotor segments 132 may be at least partially disconnected, such as by being separate members or by being connected by extensions that are narrower than adjacent rotor segments 132 in a direction perpendicular to axis of rotation 122.

[0063] The rotor 120 includes a plurality of rotor magnets 380 disposed around the rotor 120. One or more rotor magnets 380 may be coupled to corresponding side walls 134. Each rotor magnet 380 may be driven by corresponding electromagnetic fields emitted by the plurality of stator magnets 352. The plurality of rotor magnets 380 may be permanent magnets, which may have a higher flux density than superconducting magnets for the form factors of the present solution. In some embodiments, the plurality of rotor magnets 380 (and in some embodiments, the magnets 372 of the LGS 360 described below) include neodymium permanent magnets, which may have magnetic field strengths of up to 1 Tesla and may be geometrically configured in Halbach arrays to increase the magnetic field strength up to 1.4T. The time-varying nature of the electromagnetic fields 354 generated by the plurality of stator magnets 352, together with the positioning of the stator magnets 352, may drive the plurality of rotor magnets 380 to rotate about a rotor axis (e.g., rotation axis 122 shown in FIG. 2).

[0064] Each rotor blade 124, 126 may be mechanically coupled to at least one rotor magnet 380. In some embodiments, as rotor magnets 380 rotate, rotor magnets 380 may be differentially driven about rotation axis 122 by propulsion 416 caused by stator 110, rotor blades 124, 126 will rotate about a pitch axis. As shown in FIG. 4, as rotor blades 124, 126 rotate, lift 402 may be generated. A rotating wheel 508 (e.g., rubber, nylon rotating wheel) may be positioned between stator 110 and rotor 120 to allow rotor 120 to be supported and continue to rotate relative to stator 110 when rotor 120 is rotating below a threshold speed at which rotor 120 generates sufficient lift that, when combined with the functionality of the magnetic bearing system 360, overcomes gravity to support rotor 120. Rotating wheel 508 may extend between stator 110 and rotor 120 to separate stator 110 and rotor 120.

[0065] The rotor blades 124, 126 may be made of a composite construction. The composite fiber skin of the blades 124, 126 may transfer the centrifugal and bending loads of the blades 124, 126 to a shaft 418 (e.g., a feathering handle shaft). In some embodiments, shaft 418 is resisted against centrifugal and aerodynamic loads by a pair of thrust bearings 420, which may include brass bushings to compensate for the primary bending and shear moments of rotor blades 124, 126. Rotor 120 may include a support ring 422, which may be a modular assembly of a box rim mounting the blade assemblies (e.g., each blade 124, 126 and the corresponding shaft 418 and bearings 420) and drive magnets 380. Support ring 422 may include hollow disc end plates 424 to contain magnets 372, 374.

B. Systems and methods of magnetic bearing functionality and orientation of a VTOL platform

[0066] Referring now to FIGS. 3-5 and now to FIG. 6, the VTOL system 300 includes a magnetic bearing and orientation system (LGS) functionality 360 that maintains a position (and orientation) of the rotor 120 relative to the stator 110, including to allow the stator 110 to receive lift from the rotor 120 through an air gap between the rotor 120 and the stator 110 in order to move the VTOL platform 100.

Systems and methods for maintaining the magnetic bearing functionality of a rotor relative to a stator

[0067] The present solution may maintain magnetic bearing functionality of a rotor (e.g., rotor 120) relative to a stator (e.g., stator 110). In implementations where the stator drives a rotor, it may be necessary for the rotor to be spaced from the stator (e.g., to limit friction, for example). The implementations and embodiments described herein space the rotor from the stator even where the stator and rotor are lifted off the ground.

[0068] In some embodiments, a system includes a rotor and a stator. The rotor includes a sidewall and two rotor walls extending from the two ends of the sidewall such that the two rotor walls are spaced apart from each other. The rotor includes a first and a second rotor magnet coupled to respective rotor walls. The stator includes a support structure extending between the rotor walls. The stator includes a stator magnet (e.g., a first stator magnet) coupled to a first surface of the support structure adjacent to one of the rotor magnets (e.g., the first rotor magnet). The first rotor magnet induces a current in the first stator magnet corresponding to a distance between the first stator magnet and the first rotor magnet. The stator includes another stator magnet (e.g., a second stator magnet) coupled to a second surface of the support structure adjacent to the second rotor magnet. The stator magnets are electrically coupled to each other, such that the second stator magnet receives current from the first stator magnet. The second stator magnet emits a magnetic field with a magnetic field strength based on the current in the first stator magnet. The magnetic field of the second stator magnet interacts with the second rotor magnet to control a distance between the at least one second stator magnet and the at least one second rotor magnet.

[0069] For example, with further reference to FIGS. 3-5 and 6, the LGS 360 may maintain a position of the rotor 120 along the axis of rotation 122 (e.g., vertically) relative to the stator 110. For example, the LGS 360 may include a plurality of first magnets 362 and a plurality of second magnets 364 (also referred to herein as stator magnets) that are electrically coupled, passive electromagnetic coils such that a total magnetic flux through the first magnets 362 and the corresponding second magnets 364 is zero (e.g., the LGS 360 establishes a zero flux condition). Magnets 362, 364 may be coupled to respective surfaces of a support structure 510 of stator 110 extending between rotor walls 512, 514 and adjacent to a side wall 516 of rotor 120. Magnets 362, 364 may be disposed along an axis of the stator.

[0070] As the rotor 120 rotates (e.g., due to the magnet 352 coupled to the stator support structure 110 driving the magnet 380 coupled to the sidewall 516 of the rotor 120), the blades 124, 126 generate lift 402. The LGS 360 receives the lift via the first magnets 362 as the rotor 120 moves vertically along the rotor axis 122 and transfers the lift to the stator housing 350, causing the VTOL platform 100 to be raised. The LGS 360 stabilizes the position of the rotor 120 in a direction perpendicular to the rotor axis 122. For example, as a portion of the rotor 120 moves closer to or further away from the stator 110, the LGS 360 will pull or push the rotor 120 back to an equilibrium position.

[0071] As rotor 120 rotates and is lifted due to lift 402 generated by rotor blades 124, 126, magnets 372, 374 (also referred to herein as rotor magnets) that are coupled to respective rotor walls 512, 514 of rotor 120 form magnetic fields 410, 412 that apply respective forces to magnets 362, 364. Magnets 372, 374 may be permanent magnets. Magnets 372, 374 may be disposed along a rotor axis that extends parallel to the axis of rotation of rotor 120. In some embodiments, magnet(s) 372 and magnet(s) 362 may be aligned, and magnet(s) 374 and magnet(s) 364 may be aligned. In some implementations, the rotor axis may be aligned with the stator axis so that each of the magnets 362, 364, 372, 374 are aligned.

[0072] The magnitude of the force associated with the magnetic field 410 will increase as the third magnets 372 move closer to the plurality of first magnets 362, while the magnitude of the magnetic field 412 will decrease as the fourth magnets 374 move further away from the second magnets 364 (or vice versa). Movement of rotor 120 along rotor axis 122 may occur due to various phenomena during operation of VTOL system 300, including, but not limited to, when rotation of rotor 120 results in lift 402. In particular, as rotation of rotor 120 results in lift 402, rotor 120 will be driven vertically, applying a net vertical force to stator 110. In some embodiments, because first magnets 362 are electrically coupled to second magnets 364, current induced in first magnets 362 due to magnetic field 410 increasing in magnitude will be conducted to second magnets 364 (e.g., due to the zero flux condition), causing the magnitude of magnetic field 412 to increase, in turn pulling fourth magnets 374 closer to second magnets 364 and thereby maintaining a position of rotor 120 relative to stator 110 along the rotor shaft 122. The repulsive force associated with the stabilization implemented by the LGS 360 may be linear, which may facilitate the stabilization effect.

Systems and methods for improved orientation of a rotor relative to a stator

[0073] The present solution may allow for better orientation of a rotor relative to a stator (e.g., rotor 120, stator 110), so as to maintain the rotor in an appropriate position along an axis perpendicular to the rotation axis 122 in response to the rotor moving closer to or further from the stator. In implementations where the stator drives a rotor, the rotor may have a tendency to shift laterally during rotation (e.g., due to centrifugal and centripetal forces). As a result of such lateral shifts, the rotor and stator may become misaligned, which may cause the system to malfunction or even become inoperative. The implementations and embodiments described herein maintain the position of the rotor relative to the stator to prevent misalignment.

[0074] In some embodiments, a system includes a rotor and a stator. The rotor includes a sidewall and a rotor wall extending from an end of the sidewall. The rotor includes a rotor magnet coupled to the rotor wall. The stator includes a support structure adjacent to the rotor wall. The stator includes a first stator magnet and a second stator magnet. The stator magnets are coupled to a surface of the support structure proximate to the rotor magnet. The stator magnets may be electrically coupled to each other. The rotor magnet may induce a current in the first stator magnet corresponding to a magnetic force between the first stator magnet and the rotor magnet. The second stator magnet may receive current from the first stator magnet to control a magnetic force between the second stator magnet and the rotor magnet.

[0075] As shown in FIGS. 4 and 6, the first magnets 362 (e.g., stator magnets) include pairs of first magnets 362, a radially inward first magnet 362a and a radially outward first magnet 362b. The second magnets 364 (e.g., stator magnets) similarly include a second inner magnet 364a and a second outer magnet 364b. In some embodiments, first magnet 362a is electrically coupled to first magnet 362b and second magnet 364a is electrically coupled to second magnet 364b, allowing a similar zero-flux condition between corresponding magnets 362, 364. In a balanced position, magnets 362a, 364a are inside of corresponding magnets 372, 374 (e.g., rotor magnets) and magnets 362b, 364b are outside of corresponding magnets 372, 374. If rotor 120 moves toward stator 110, the magnitude of magnetic fields 376 will change to counteract the displacement. For example, as rotor 120 and thus magnets 372, 374 move closer to the axis of rotor 122, magnets 372, 374 will move toward magnets 362a, 364a and further toward magnets 362b, 364b. As such, the distance between magnets 372, 374 and magnets 362a, 364a increases. In turn, the magnitude of a first field 604a (e.g., a magnetic force of the first magnetic field 604a) between magnet 372 and magnet 362a will increase, while the magnitude of a second field 604b (e.g., a magnetic force of the second magnetic field 604b) between magnet 372 and magnet 362b will decrease (likewise for magnet 374 and magnets 364a, 364b). As the magnitude of field 604a increases, current is induced in magnet 362a. Because magnets 362a, 362b are electrically coupled, changes in the induced currents between magnets 362a, 362b will counteract the motion of magnet 372 and thus move rotor 120 back to the equilibrium position. The induced current between magnets 362a, 362b, 364a, 364b can control the magnetic force between magnets 372, 374 and magnets 362a, 362b, 364a, 364b to move rotor 120 back to the equilibrium position.

C. Systems and control methods of a VTOL platform

[0076] Referring now to FIGS. 7-9, a flight controller 700 is shown in accordance with one embodiment of the present disclosure. The flight controller 700 may incorporate features of the flight controller 316 described with reference to FIG. 3, including for generating instructions to control the movement of a VTOL platform (e.g., VTOL platform 100 described with reference to FIGS. 1-3). For example, the flight controller 700 may generate commands to cause thrust, yaw, pitch, and roll motion of the VTOL platform (e.g., thrust, moment of force about the yaw axis, moment of force about the platform pitch axis, moment of force about the platform roll axis).

Systems and methods for controlling the drive of a rotor with magnetic bearing functionality

[0077] The present solution may be used to control the operation of the rotor 120 to control the movement of the VTOL platform 100 so as to cause the rotor 120 to generate lift. In some embodiments, the flight controller 700 includes a flight dynamics model 702. The flight dynamics model 702 may calculate variables associated with the movement of the VTOL platform 100. For example, the flight dynamics model 702 may model relationships between thrust, drag, and gravity acting on the VTOL platform 100. The flight dynamics model 702 may calculate lift corresponding to forces acting on the VTOL platform 100. The flight dynamics model 702 may include a function that calculates a thrust generated by each rotor blade (e.g., rotor blades 124, 126) based on a pitch angle of each rotor blade; Similarly, the flight dynamics model 702 may calculate a total thrust generated by all rotor blades (e.g., a magnitude and direction of the total thrust) based on the pitch angle of all rotor blades.

[0078] The flight controller 700 includes a flight dynamics controller 704. The flight dynamics controller 704 may include flight dynamics control laws used to generate control commands 708 to cause the VTOL platform 100 to perform desired motion, such as selectively controlling (e.g., via motor controller 1000 and stator system 1100, as described below) the stator magnets 352 to produce respective magnetic fields that interact with the rotor magnets 380 to rotate the rotor 120 about the rotation axis 122 to generate lift, and to control the operation of the rotor blades 124, 126 to control an angle of the rotor blades 124, 126 about respective blade axes 440. In particular, the flight dynamics controller 704 may generate a vertical command 708a, a pitch command 708b, a vertical command 708c, a vertical command 708d, a vertical command 708e, a vertical command 708f, a vertical command 708f, a vertical command 708f, and a vertical command 708f. yaw command 708c and a roll command 708d. Flight dynamics controller 704 may generate commands 708a, 708b, 708c, 708d by mapping the pitch angles of each rotor blade to the corresponding thrust generated by each rotor blade and mapping the thrust of each rotor blade to the resulting thrust (e.g., total thrust), yaw, pitch, and roll. Flight dynamics controller 704 may generate command 708b for a moment force about the yaw axis, command 708c for a moment force about the pitch axis, and command 708d for a moment force about the roll axis.

[0079] Flight dynamics controller 704 may generate vertical command 708a to indicate a desired vertical movement of VTOL platform 100. For example, flight dynamics controller 704 may generate vertical command 708a to indicate a desired elevation to be achieved by VTOL platform 100.

[0080] Flight dynamics controller 704 may generate vertical command 708a to perform collective rotor pitch control to generate vertical acceleration, such that the upper and lower rotor disks (e.g., upper disk corresponding to rotor blades 124, lower disk corresponding to rotor blades 126, as shown in FIGS. 1-5) may increase or decrease thrust equally to negate yaw torque at a center of VTOL platform 100. Flight dynamics controller 704 may generate vertical command 708a to control thrust by collectively changing a pitch angle of each of rotor blades 124, 126, independent of an angular position of each rotor blade 124, 126 relative to rotation axis 122.

[0081] For example, as shown in FIG. 8, flight dynamics controller 704 may cause rotor blades 800 (e.g., illustrating an implementation of rotor blades 124 or rotor blades 126) to have a pitch angle resulting in individual thrusts 802 parallel to a rotor axis 806, resulting in total thrust 804 parallel to the rotor axis 806. FIG. 8 illustrates each rotor blade 800 having the same pitch angle about their respective pitch axes, such as pitch axis 808 illustrated for one of rotor blades 800.

Systems and methods for independent pitch control of rotor blades to achieve directional control

[0082] The present solution may be used to independently control the pitch of each rotor blade 800, enabling directional control of the VTOL platform (e.g., thrust, pitch, yaw, roll control). For example, the flight dynamics controller 704 may perform cyclic rotor pitch control to control the pitch and roll of the VTOL platform 100. For example, as shown in FIG. 9 , the flight dynamics controller 704 may cause a first rotor blade 900 to have a pitch corresponding to a greater thrust 902a than the remaining rotor blades 900, particularly than a lesser thrust 902b of the rotor blade 900 opposite the first rotor blade 900, resulting in a total thrust 904 having a horizontal component relative to the rotor axis 906, the horizontal component corresponding to a greater amount of thrust being generated on a first side of the rotor axis 906 where the first rotor blade 900 is located. As will be described with reference to FIGS. 11-12, as rotor blades 900 rotate about rotor axis 906, flight dynamics controller 704 may cause each rotor blade 900 to achieve a desired pitch angle as a function of the position of rotor blade 900. For example, to achieve the total thrust 904 illustrated in FIG. 9 for a desired period of time, flight dynamics controller 704 may generate commands to cause each rotor blade 900 to change its pitch angle through the various pitch angles shown in FIG. 9 as rotor blades 900 rotate about rotor axis 906. As discussed further herein, the pitch angle of each rotor blade 900 may be controlled through various mechanisms, such as a motor coupled to rotor blade 900 to rotate rotor blade 900 or rotor magnets coupled to rotor blade 900 that may be driven by stator magnets to rotate rotor blade 900.

[0083] In some embodiments, the flight dynamics controller 704 uses an operator input 706 (which may be received from the user interface 340 described with reference to FIG. 3) to generate the control commands 708. For example, the flight dynamics controller 704 may extract movement instructions indicated by the operator input to generate the control commands 708. In some embodiments, the flight dynamics controller 704 uses an autopilot to generate the control commands 708. For example, the autopilot may provide a target destination to the flight dynamics controller 704, such as a waypoint in a flight plan. The autopilot may provide a plurality of target destinations over time to define a path for the VTOL platform 100 to follow (e.g., a path through a plurality of waypoints).

[0084] Flight dynamics controller 704 may use flight dynamics model 702 to generate control commands 708. For example, flight dynamics controller 704 may use flight dynamics model 702 to calculate a lift expected to be generated by rotor 120 given pitch angles of the rotor blades. Flight dynamics controller 704 may execute flight dynamics control laws to convert instructions indicative of desired motion (e.g., instructions elicited via operator input indicating desired motion to a higher altitude at a given vertical speed and airspeed) and use flight dynamics model 702 to determine how to control the operation of rotor blades 900 to generate the expected lift, yaw, pitch, and/or roll to achieve the desired motion.

[0085] The flight dynamics controller 704 issues the control commands 708 to a first network 710. The first network 710 may be a communication bus, such as a controller area network (CAN) bus, a local interconnect network (LIN) bus, or a filled jittering operating network (PJON). The first network 710 may operate using a microcontroller stack network stack protocol.

[0086] Referring now to FIG. 10, a motor controller 1000 is shown in accordance with one embodiment of the present disclosure. The motor controller 1000 may incorporate features of the motor controller 318 described with reference to FIG. 3, including generating electronic instructions for controlling the operation of a stator of a VTOL platform (e.g., stator 110 and VTOL platform 100 described with reference to FIGS. 1-3).

[0087] The motor controller 1000 includes at least one motor control circuit 1002. For example, as shown in FIG. 10, the motor controller 1000 includes a first motor control circuit 1002a, a second motor control circuit 1002b, and a third motor control circuit 1002c. The at least one motor control circuit 1002 may receive control commands from the first network 710 (e.g., control commands 708 as described with reference to FIG. 7) and generate motor control signals 1004 to be sent to the stator 110 via the second network 1006. The second network 1006 may be similar to the first network 710.

[0088] For example, as shown in FIG. 10, the first motor control circuit 1002a may output the first motor control signal 1004a, the second motor control circuit 1002b may output the second motor control signal 1004b, and the third motor control circuit 1002c may output the third motor control signal 1004c. In some embodiments, the number of motor control circuits 1002 corresponds to the number of operating phases of stator magnets 110; for example, the motor controller 1000 shown in FIG. 10 may be configured for three-phase operation. The motor controller 1000 may perform synchronous control of the stator 110 and may maintain a constant rotational speed of the rotor 120 by maintaining a source frequency of the control signals of the motor 1004, including for any load condition that is less than a maximum rated load.

[0089] As will be described with further reference to FIG. 11, the at least one motor control circuit 1002 may generate motor control signals 1004 to cause specific waveforms to be applied to stator electromagnets 110 to cause resultant motion of rotor magnets 120. The motor controller 1000 includes a position encoder 1004 that receives a position signal 1010 from a third network 1008. The third network 1008 may be similar to the first network 710 and the second network 1006.

[0090] Position signal 1010 indicates positions of rotor magnets 120, which position encoder 1004 can convert to position data that the at least one motor control circuit 1002 can use to determine which stator electromagnets 110 to control (and thus how to generate the waveforms to be applied to the stator electromagnets 110).

Systems and methods for dynamically triggering independent stator coils to control rotor rotational speed

[0091] Referring now to FIG. 11, a stator system 1100 is shown in accordance with one embodiment of the present disclosure. The stator system 1100 may incorporate features of the stator 110 described with reference to FIGS. 1-5. The stator system 1100 includes at least one magneto controller 1102, such as magneto controllers 1102a, 1102b, and 1102c, which may each execute a phase of a three-phase control scheme. The at least one magneto controller 1102 receives motor control signals 1004 from the second network 1006. For example, as depicted in FIG. 11, the first magneto controller 1102a receives the first motor control signal 1004a, the second magneto controller 1102b receives the second motor control signal 1004b, and the third magneto controller receives the third motor control signal 1004c. The stator system 1100 may be used to independently drive stator electromagnets 110 (e.g., stator coils) or groups of electromagnets to output magnetic fields that may be used to rotate the rotor 110 at desired rotation rates about the rotation axis 122.

[0092] The stator system 1100 includes a plurality of electromagnets (e.g., electromagnetic coils). FIG. 11 illustrates nine pairs of electromagnets 1110, 1112; 1114, 1116; 1118, 1120; 1122, 1124; 1126, 1128; 1130, 1132; 1134, 1136; 1138, 1140. One electromagnet of each pair may be provided on a corresponding stator rail 404 or 408, as shown in FIG. 4. For example, electromagnets 1110, 1114, 1118, 1122, 1126, 1130, 1134, 1138, and 1142 may be provided on stator rail 404, and electromagnets 1112, 1116, 1120, 1124, 1128, 1132, 1136, 1140, and 1144 may be provided on stator rail 408. Although FIG. 11 illustrates stator system 1100 including nine pairs of electromagnets controlled by three magnet controllers 1102a, 1102b, and 1102c, it will be understood that stator system 1100 may include such additional modules of magnet controllers and electromagnets—for example, stator system 1100 may include a circumferential ring of magnet controllers and electromagnets to enable stator system 1100 to drive rotor 120 around rotational axis 122.

[0093] The first magnet controller 1102a may control the operation of the electromagnets 1110, 1112; 1122, 1124; and 1134, 1136. For example, the first magnet controller 1102a may transmit individual magnet control signals to each of the electromagnets 1110, 1112; 1122, 1124; and 1134, 1136. In some embodiments, the stator system 1100 includes a first actuator 1142 coupled to the electromagnet 1110 and a second actuator 1144 coupled to the electromagnet 1112. The first actuator 1142 and the second actuator 1144 may be implemented using a switching circuit, such as a metal-oxide-semiconductor field-effect transistor (MOSFET). The stator system 1100 may include an actuator coupled to each electromagnet (as depicted in FIG. 11).

[0094] The at least one magnet controller 1102 may transmit magnet control signals to control the operation of the electromagnets, such as by performing pulse width modulation (PWM) based on the received motor control signals 1004 to control at least one of a current or a voltage of the magnet control signal output based on the received motor control signals 1004. For example, by increasing a duty cycle of the control signals using PWM, the at least one magnet controller 1102 may cause the electromagnets to generate magnetic fields with relatively greater field strengths. The first magnet controller 1102a may transmit a first magnet control signal to cause the first actuator 1142 to drive a first electrical signal through the electromagnet 1110, causing the electromagnet 1110 to emit a corresponding first magnetic field, and may transmit a second magnet control signal to cause the second actuator 1142 to drive a second electrical signal through the electromagnet 1112 to emit a corresponding second magnetic field. Because magnet controllers 1102 control the electromagnets (e.g., based on the magnetic force output of the electromagnets, based on a switching rate between the electromagnets emitting magnetic fields, and so on), magnet controller 1102 may control the rotational speed of rotor 120 relative to stator 110. The switching rate may correspond to a rate of current being conducted through the respective electromagnets or a rate of pulse output by the at least one magnet controller 1102. Magnet controllers 1102 may modify the switching rate by changing a rate at which the electromagnets are sequentially excited to produce a respective magnetic field. Magnet controllers 1102 may modify the magnetic force (e.g., based on the magnitude of the magnetic field strength of the respective magnetic field) by increasing the current, increasing the duty cycle, and so on. For example, magnet controller 1102 may increase the magnetic force to increase the rotational speed, increase the switching rate to increase the rotational speed, and so on. By increasing the rotational speed, rotor blades 124, 126 may produce more lift. In some embodiments, magnet controller 1102a may control electromagnets 1110, 1112; 1122, 1124; and 1134, 1136 at a first switching rate, and second magnet controller 1102b may control electromagnets 1114, 1116; 1126, 1128; and 1138, 1140 at a second switching rate different from the first switching rate.

[0095] The second magnet controller 1102b may control the operation of the electromagnets 1114, 1116; 1126, 1128; and 1138, 1140. For example, the second magnet controller 1102b may transmit individual magnet control signals to each of the electromagnets 1114, 1116; 1126, 1128; and 1138, 1140. The third magnet controller 1102c may control the operation of the electromagnets 1118, 1120; 1130, 1132; and 1142, 1144. For example, the third magnet controller 1102c may transmit individual magnet control signals to each of the electromagnets 1118, 1120; 1130, 1132; and 1142, 1144. Because magnet controllers 1102 control the electromagnets (e.g., based on the magnetic force output of the electromagnets, based on a switching rate between the electromagnets emitting magnetic fields, and so on), magnet controller 1102 can control the rotational speed of rotor 120 relative to stator 110. Magnet controllers 1102 can modify the switching rate by changing the rate at which the electromagnets are sequentially excited to produce a respective magnetic field. For example, magnet controller 1102 can increase the magnetic force to increase the rotational speed, increase the switching rate to increase the speed, and so on. By increasing the speed, rotor blades 124, 126 can produce more lift.

Systems and methods for dynamically triggering independent stator coils to control rotor blade pitch

[0096] The present solution may be used to control the pitch angles of rotor blades 1164 by independently driving and controlling the operation of electromagnets or groups of electromagnets of stator system 1100, in turn controlling the respective magnetic fields produced by the electromagnets interacting with rotor 120 and its magnets. For example, magnet controllers 1102 may output control signals with duty cycles, magnitudes, switching rates, or other parameters that selectively control the electromagnets of stator system 1100 to emit desired magnetic fields. In the configuration depicted in FIG. 11 , the third magnet controller 1102c outputs a magnet control signal to cause the electromagnet 1120 to generate an electromagnetic field 1152. The third magnet controller 1102c configures the electromagnetic field 1152 to repel a first rotor magnet 1160 (e.g., a lower rotor magnet of the two rotor magnets 380 interacting with the rotor blade 124, as shown in FIGS. 4-5), such as by timing a magnitude and polarity of the electromagnetic field 1152 to repel a corresponding lagging side pole of the first rotor magnet 1160. The second magnet controller 1102b outputs a magnet control signal to cause the electromagnet 1128 to generate an electromagnetic field 1154, which is configured to attract the first rotor magnet 1160, such as timing a magnitude and polarity of the electromagnetic field 1154 to attract a corresponding leading-side pole of the first rotor magnet 1160. As such, the stator system 1100 may drive the first rotor magnet 1160 at a desired speed along direction 1170 by controlling the timing, magnitude, and/or polarity of the emitted magnetic fields. Likewise, in the configuration depicted in FIG. 11, the first magnet controller 1102a outputs a magnet control signal to cause the electromagnet 1122 to emit an electromagnetic field 1156 to repel a lagging-side pole of a second rotor magnet 1162, and the third magnet controller 1102c outputs a magnet control signal to cause the electromagnet 1130 to produce an electromagnetic field 1158 to attract a leading-side pole of the second rotor magnet 1162, thereby driving the second rotor magnet 1162 at a desired speed (which may be different from the speed at which the first rotor magnet 1160 is driven) along the direction 1170.

[0097] Rotor blade 1164 is coupled to first and second rotor magnets 1160, 1162 and therefore can be driven along direction 1170 by movement of first and second rotor magnets 1160, 1162. As such, stator system 1100 can generate desired lift based on the speed at which rotor blade 1164 is driven as well as the tilt angle at which rotor blade 1164 is oriented. As will be described with further reference to FIG. 12, the stator system 1100 may selectively retard and drive the first and second rotor magnets 1162, 1164 relative to each other (based on motor control signals 1004 received from the motor controller 1000) to adjust the pitch angle of the rotor blade 1164, enabling pitch, yaw, and roll control. Furthermore, the stator system 1100 may maintain synchronicity with the rotor magnets 1160, 1162 due to the combined attraction and repulsion applied to each pair of rotor magnets 1160, 1162.

[0098] As the rotor magnets 1160, 1162 are driven along direction 1170, the at least one magnet controller 1102 may continue to use the received motor control signals 1004 to selectively activate the electromagnets (including the depicted electromagnets 1110, 1112; 1114, 1116; 1118, 1120; 1122, 1124; 1126, 1128; 1130, 1132; 1134, 1136; 1138, 1140) and thereby drive the rotor magnets 1160, 1162 through a complete rotation about the stator system 1100.

[0099] Stator system 1100 includes a position encoder 1104. Position encoder 1104 may transmit a position signal indicating a position of each rotor blade (e.g., rotor blade 1164) via third network 1008 to position encoder 1004 of motor controller 1000, such that motor controller 1000 may use the position of each rotor blade to generate appropriate motor control signals 1004 for transmitting to stator system 1100. Position encoder 1004 may be distributed throughout stator 110 in a manner similar to the configuration of stator system 1100 shown in FIG. 11 may be distributed throughout stator 110 to allow for full circumferential operation.

[0100] Position encoder 1104 may include a back electromotive force (EMF) encoder that measures a back EMF from each electromagnet of stator system 1100 and determines the positions of rotor magnets 1160, 1162, and thus rotor blades 1164, based on the back EMF. For example, in each motor control state, position encoder 1104 may detect a back EMF from a distributed selection of unpowered electromagnets of stator system 1100; zero-crossing of the voltage signal across each of the electromagnets may indicate passage of corresponding rotor magnets 1160, 1162 over the center of the electromagnet coil. The position encoder 1104 and/or the position encoder 1004 of the motor controller 1000 may use a high resolution of the rotor magnet positions, combined with a Kalman filter, to produce a high-speed measurement and prediction of blade position/pitch for a large number of blades, in order to generate motor control signals 1004 with highly accurate timing.

Systems and methods for variable blade pitch control

[0101] The present solution may enable various solutions for independent and variable pitch control of rotor blades (e.g., rotor blades 124, 126, 1164), enabling directional control of VTOL platform 100 based on the individual and collective pitches (e.g., pitch angle) of the rotor blades. In implementations where VTOL platform 100 is used as a vehicle, it may be desirable to move VTOL platform 100 in different directions. The systems and methods described herein may modify the pitch angle of the rotor blades to achieve a desired overall motion of the rotor and thus VTOL platform 100.

[0102] In some embodiments, the system includes a rotor and a stator. The rotor includes a first rotor magnetic component aligned with one or more first stator coils. The rotor includes a second rotor magnetic component aligned with one or more second stator coils and adjacent to the first rotor magnetic component. The rotor includes an arm connecting the first rotor magnetic component and the second rotor magnetic component. A first arm end of the arm is coupled to the first rotor magnetic component and a second arm end of the arm is coupled to the second rotor magnetic component, which together define an arm angle that changes based on a first magnetic force applied to the first rotor magnetic component relative to a second magnetic force applied to the second rotor magnetic component. The rotor includes a first rotor blade attached to the arm, the first rotor blade extending from the arm along a blade pitch axis. The first rotor blade defines a blade pitch angle relative to the blade pitch axis with the blade pitch angle corresponding to the arm angle. The stator includes a plurality of electromagnets configured to emit at least a first magnetic field that drives the first magnetic component of the rotor and a second magnetic field that drives the second magnetic component of the rotor responsive to control signal(s). The control signals cause the first magnetic field to apply the first magnetic force to the first magnetic component of the rotor and the second magnetic field to apply the second magnetic force to the second magnetic component to control the blade pitch angle.

[0103] In some embodiments, the system includes a rotor and a stator that rotates the rotor about a rotation axis. The rotor includes an annular rotor base defining the rotation axis and including a plurality of rotor segments disposed about the stator. Each rotor segment includes a first rotor blade configured to be rotated about a blade pitch axis perpendicular to the rotation axis. The rotor segments include a power receiver circuit. The rotor segments include a motor that rotates using power received through the power receiver circuit to rotate the first rotor blade about the blade pitch axis. The rotor segments include a motor controller that provides a motor signal to the motor to rotate the first rotor blade about the blade pitch axis in response to a control signal. The rotor segments include a first wireless transceiver that receives the control signal and provides the control signal to the motor controller. The stator includes a second wireless transceiver that receives a control command and wirelessly transmits the control signal to the first wireless transceiver based on the control command. The stator includes a power transmitter circuit that emits a magnetic field that interacts with the power receiver circuit to supply power to the power receiver circuit.

[0104] Referring now to FIG. 12, a rotor control system 1200 is shown in accordance with one embodiment of the present disclosure. The rotor control system 1200 may enable frictionless blade pitch control and may avoid difficulties that may arise from applying traditional pitch control approaches to the form factors achieved by the present solution. For example, existing systems typically use a swash plate to transfer directional control inputs to rotor pitch control. However, when applied to a larger radius rotating at a comparable rotational rate, the radial speed of the annulus hub can be significantly higher, which can result in much higher frictional losses, require more material to withstand cyclic loads in fatigue strength, resulting in more heavily reinforced bearing solutions, may require complex cooling methods, may result in large amounts of wear and more maintenance, and may increase mechanical noise from the cyclic loading of high-speed bearings, which may mitigate the improved noise performance that could be achieved by the annulus and electric motor configuration. The 1200 rotor control system can avoid these difficulties by driving rotor blade rotation using controlled electromagnetic fields across an air gap.

[0105] As shown in FIG. 12 , the rotor control system 1200 includes a first (e.g., upper) magnetic member 1202 supporting the first rotor magnet 1160 and a second (e.g., lower) magnetic member 1204 supporting the second rotor magnet 1162. The first magnet member 1202 is coupled to the second magnet member 1204 by an arm 1206. A rotor blade (e.g., rotor blade 1164 described with reference to FIG. 11) is attached to the arm 1206 such that when the arm 1206 rotates about a tilt axis (extending into the view shown in FIG. 12) perpendicular to a direction of movement 1208 of the magnet members 1202, 1204 (the direction of movement 1208 being about a rotor axis (e.g., rotation axis 122 shown in FIG. 2)), a pitch angle 1210 of the rotor blade will vary.

[0106] An upper stator rail electromagnet 404 emits a first electromagnetic field that applies a first force to the first motor magnet 1160, causing the first magnet element 1202 to be driven forward in direction 1211. The first force will depend on the electric current conducted through the upper stator rail electromagnet 404 (as described with reference to FIG. 11), as well as a spatial relationship between the upper stator rail 404 and the first motor magnet 1160. Likewise, a lower stator rail electromagnet 408 emits a second electromagnetic field that applies a second force to the second rotor magnet 1162 to drive the second magnet element 1204 forward in direction 1212. Based on the initial positions of the magnet members 1202, 1204 and the magnitudes of the first and second forces, the magnet members 1202, 1204, and the magnitudes of the first and second forces, the upper stator rail electromagnet 404 and the first motor magnet 1160 may be driven forward in direction 1212. 1202, 1204 will move to positions resulting in a lag/lead distance 1218 between magnet members 1202, 1204 (e.g., as measured from planes 1214, 1216 at the ends of magnet members 1202, 1204). Lag/lead distance 1218 corresponds to tilt angle 1210 as arm 1206 is attached to magnet members 1202, 1204 and will rotate as lag/lead distance 1218 changes.

[0107] In various embodiments, the synchronization force of the electromagnetic fields that the stator (e.g., stator 110, stator system 1100) applies to the rotor magnets 1160, 1162 may be approximately the same in magnitude as a maximum driving force of the stator. As such, rotor control system 1200 may be configured such that stator and corresponding magnet members 1202, 1204 (e.g., rotor magnets 1160, 1162) are sized to produce a moving electromagnetic field across an air gap between stator rails 404, 408 and magnet members 1202, 1204 that is large enough that a minimum linear driving force from the stator to an individual magnet member 1202, 1204, between phases, is greater than a maximum combination of the following forces: peak blade drag on the rotor blade (e.g., rotor blade 1164), a reactionary force from a peak aerodynamic pitching moment about a 1/4 chord of the rotor blade, and a reactionary force from a maximum rotational inertia of the blade about a diffusion axis of the rotor blade at a maximum cyclic pitch adjustment in overspeed operation. In several of these embodiments, the number of rotor blades can be selected based on such factors, as too few blades can lead to large magnet arrays mounted on each rotor blade hub, and too many rotor blades can lead to increased weight.

[0108] Referring now to FIG. 13, a method 1300 for controlling the operation of a VTOL platform is shown in accordance with one embodiment of the present disclosure. The method 1300 may be implemented using various systems and components disclosed herein, including the VTOL platform 100, the VTOL system 300, the flight controller 700, the motor controller 1000, the stator system 1100, and the rotor control system 1200.

[0109] At 1305, a flight controller of a VTOL platform receives a movement instruction indicating a desired movement of the VTOL platform. The operation instruction may be received from a user interface configured to receive user input. The operation instruction may be received from an autopilot; for example, the desired movement may be indicated as movement toward a waypoint of a flight plan.

[0110] At 1310, the flight controller generates one or more flight control commands based on the desired motion. The flight controller may use a flight dynamics model to generate one or more flight control commands. For example, the flight dynamics controller may use the flight dynamics model to calculate the lift expected to be generated by a VTOL platform rotor, given the pitch angles of the VTOL platform rotor blades. The flight dynamics controller may execute flight dynamics control laws to convert instructions indicative of the desired motion (e.g., instructions elicited via operator input indicating desired motion to a higher altitude at a given vertical speed and airspeed) and use the flight dynamics model to determine how to control the operation of the rotor blades to generate the expected lift, yaw, pitch, and/or roll to achieve the desired motion. In some embodiments, the flight controller generates one or more flight control commands to execute collective pitch control to cause the VTOL platform to generate lift. In some embodiments, the flight controller generates one or more flight control commands to execute cyclic pitch control to cause the VTOL platform to generate movement over pitch and/or roll angles.

[0111] At 1315, a motor controller generates one or more motor control signals based on the flight control command(s). The motor controller may generate the motor control signals to cause specific waveforms to be applied to the electromagnets of a stator of the VTOL platform in order to cause the electromagnets to generate electromagnetic fields expected to cause the VTOL platform to perform the desired motion indicated by the motion instruction. In some embodiments, the motor controller receives a position signal indicating the positions of the rotor blades, which the motor controller may use to generate the motor control signals to individually control the operation of each rotor blade. The motor controller may generate the motor control signals and provide the motor control signals, via one or more transceivers, to control the operation of the motors coupled to the rotor blades to rotate the rotor blades to the desired pitch angles.

[0112] At 1320, the stator drives the stator electromagnets based on motor control signals. For example, the stator may use a plurality of magneto controllers to drive electrical signals at the desired current and/or voltage to each electromagnet based on motor control signals. The magneto controllers may perform PWM to drive electrical signals through each electromagnet. In some embodiments, the magneto controllers operate switching circuits, such as MOSFET circuits, to selectively drive electrical signals through each electromagnet based on motor control signals. In some embodiments, the magnetic bearing/orientation functionality of the stator output magnetic fields interacts with the corresponding rotor magnets to rotate the rotor.

[0113] At 1325, the electromagnets emit electromagnetic fields corresponding to the electrical signals driven through each electromagnet. The rotor magnets, in turn, are moved by the electromagnetic fields. In some embodiments, the rotor includes a plurality of rotor blades, each coupled to a pair of magnets via a rotor arm, such that selective movement of the magnets can vary a rotor blade pitch angle, resulting in desired lift, yaw, pitch, and/or rotation. In some embodiments, the rotor motors receive power via the electromagnetic fields and use the power to rotate the respective rotor blades.

[0114] Referring now to FIGS. 14A and 14B, a rotor control system 1400 is shown in accordance with one embodiment of the present disclosure. Various elements and components shown in the embodiment depicted in FIGS. 14A and 14B are similar to the elements and components described above with reference to FIGS. 1-13. Therefore, the same reference numerals are used to indicate similar features. The rotor control system 1400 is shown to include a blade controller 1402. The blade controller 1402 may be any element, device, component, script, etc. designed or implemented to control the movement of the rotor blades 124, 126 to produce or achieve a desired movement. The blade controller 1402 may be similar in some respects to the flight controller 700 described above. In some implementations, the blade controller 1402 may be incorporated into or a component of the flight controller 700. The blade controller 1402 may be configured to determine a desired pitch angle for the rotor blade(s) 124, 126 (e.g., a blade tilt angle). The blade controller 1402 may determine (e.g., based on a maintained command log, based on data from an encoder coupled directly or indirectly to the rotor blade 124, 126, etc.) a current position of the rotor blade(s) 124, 126. The blade controller 1402 may be configured to modify the pitch angle for the rotor blade(s) 124, 126 to achieve the desired pitch angle to result in a desired motion. As described in more detail below, the blade controller 1402 may be configured to generate motor control signals to a motor 1404 coupled to the rotor blade(s) 124, 126 to move the rotor blade(s) 124, 126 to the desired pitch angle.

[0115] The blade controller 1402 may be configured to generate motor control signals to communicate with the motor 1404 to move the motor 1404. In some implementations, the blade controller 1402 may generate a Pulse Width Modulated (PWM) signal for the motor 1404. The PWM signal may have a duty cycle that moves the motor a certain number of steps or angle of rotation. The blade controller 1402 may communicate the motor control signals to the motor through the stator 110. In some implementations, each rotor blade 124, 126 may correspond to a dedicated blade controller 1402. In other implementations, a plurality of rotor blades 124, 126 may be controlled by a common blade controller 1402.

[0116] Blade controller 1402 is shown as being coupled to a transceiver 1406 of stator 110, which is communicably coupled to a transceiver 1408 of rotor 120. Transceivers 1406, 1408 may be any device(s), component(s), element(s), circuit(s), etc. designed or implemented to transmit data wirelessly over a distance. Transceivers 1406, 1408 may be configured to communicate according to various protocols. For example, transceivers 1406, 1408 may be configured to communicate via a ZigBee (e.g., high frequency) data transmission protocol. In still other embodiments, transceivers 1406, 1408 may be configured to communicate via a near-field communication (NFC) protocol, a Radio Frequency Identification (RFID) protocol, an infrared (IR) or other free-space optical communication transmission protocol, etc.

[0117] The stator 110 is shown to include a power transmission circuit 1410. The power transmission circuit 1410 may be any device(s), component(s), element(s), or circuit(s) designed or implemented to transmit power over a distance. The rotor 120 may correspondingly include a power receiver circuit 1412. The power receiver circuit 1412 may be any device(s), component(s), element(s), or circuit(s) designed or implemented to receive power over a distance. The power receiver circuit 1412 may be any device(s), component(s), element(s), or circuit(s) designed or implemented to receive power over a distance. In some implementations, the power transmission circuit 1410 and the power receiver circuit 1412 may be coupled to each other via magnetodynamic coupling. In other implementations, the power transmitter circuit 1410 and the power receiver circuit 1412 may be coupled to each other via inductive coupling (e.g., Qi or some other form of inductive coupling), resonant inductive coupling, laser coupling, and so on. The power receiver circuit 1412 may be configured to transfer the power received from the power receiver circuit 1410 to the transceiver 1408 of the rotor 120 and to the motor 1404. Thus, the transceiver 1408 and the motor 1404 may be wirelessly powered. In some implementations, the power receiver circuit 1412 may include a rectification circuit (e.g., via diode arrays) to rectify an AC source to drive a DC load as needed. In some implementations, the power receiver circuit 1412 may include a step-up or step-down circuit to increase (or decrease) a voltage/current/power to drive a specific load or device (such as motor 1404 or transceiver 1408 of rotor 120).

[0118] The transceiver 1408 of the rotor 120 may be configured to receive wireless motor control signals from the transceiver 1406 of the stator 110. The transceiver 1408 may be configured to provide the motor control signals to the motor 1404. The motor 1404 may be configured to drive the rotor blade(s) 124, 126. The motor 1404 may be or include various types of motors 1404 designed or implemented to control the position of the rotor blade(s) 124, 126. For example, the motor 1404 may be an air core PM-BLDC motor. In other embodiments, the motor 1404 may be a tilt motor, a gear tooth servo actuator (e.g., remote control (RC)) motor, an iron core PM-BLDC, or another type of motor. The motor 1404 may be configured to receive motor control signals from the blade controller 1402 via the transceivers 1406, 1408. The rotor 120 may include an encoder coupled to the motor 1404 and/or rotor blade(s) 124, 126 configured to detect a position of the motor 1404 and/or rotor blade(s) 124, 126. The encoder may be configured to provide data corresponding to the position of the motor 1404/rotor blade(s) 124, 126 to the blade controller 1402, which the blade controller 1402 uses as feedback to adjust the position of the rotor blade(s) 124, 126.

[0119] References to "or" may be construed as inclusive, such that any terms described using "or" may indicate any one, more than one, and all of the described terms. References to at least one of a conjunctive list of terms may be construed as an inclusive OR to indicate any one, more than one, and all of the described terms. For example, a reference to “at least one of 'A' and 'B'” may include only 'A', only 'B', as well as both 'A' and 'B'. Such references used in conjunction with "comprising" or other open-ended terminology may include additional items.

[0120] The construction and arrangement of the systems and methods as shown in the various exemplary embodiments are illustrative only. Although only exemplary embodiments have been described in detail in this disclosure, many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes, and ratios of the various elements, parameter values, mounting arrangements, use of materials, colors, orientations, etc.). For example, the position of the elements may be reversed or otherwise varied, and the nature or number of discrete elements or positions may be changed or varied. Accordingly, such modifications are intended to be included within the scope of the present disclosure. The order or sequence of any steps of the process or method may be varied or resequenced according to alternative embodiments. Other substitutions, modifications, changes, and omissions may be made in the design, operating conditions, and arrangement of the exemplary embodiments without departing from the scope of the present disclosure.

[0121] The present disclosure contemplates methods, systems, and program products on any machine-readable medium for performing various operations. Embodiments of the present disclosure may be implemented using existing computer processors, or by a special-purpose computer processor for an appropriate system, embedded for this or another purpose, or by a wired system. Embodiments within the scope of the present disclosure include program products comprising machine-readable media for carrying or having machine-executable instructions or data structures stored thereon. Such machine-readable media may be any available media that can be accessed by a general-purpose or special-purpose computer or other machine with a processor. By way of example, such machine-readable media may comprise RAM, ROM, EPROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of machine-executable instructions or data structures and that can be accessed by a general-purpose or special-purpose computer or other machine with a processor. Combinations of the above items are also included in the scope of machine-readable media. Machine-executable instructions include, for example, instructions and data that cause a general-purpose computer, special-purpose computer, or special-purpose processing machine to perform a specific function or group of functions.

[0122] Although the figures show a specific order of method steps, the order of the steps may differ from what is depicted. Furthermore, two or more steps may be performed simultaneously or with partial concurrency. This variation will depend on the software and hardware systems chosen and the designer's choice. All such variations are within the scope of the disclosure. Similarly, software implementations may be implemented using standard programming techniques with rule-based logic and other logic to perform the various connection steps, processing steps, comparison steps, and decision steps.

Claims (8)

1. A vertical takeoff and landing (VTOL) vehicle system (300) comprising: a stator (110) comprising a first stator magnet, a second stator magnet, and one or more propulsion magnets (352) configured to emit a magnetic field that interacts with at least a third rotor magnet (380) to rotate a rotor about a rotational axis (122) relative to the stator (110); a rotor (120) comprising an annular rotor base (128) defining an axis of rotation (122) and comprising a plurality of rotor segments (132) disposed about the stator (110), each rotor segment (132) including a side wall (134) spaced from the axis of rotation (122), a first rotor wall extending from a first end of the side wall (134) and toward the axis of rotation (122), and a second rotor wall extending from a second end of the side wall (134) and toward the axis of rotation (122), the second rotor wall spaced from the first rotor wall, the rotor defining a rotor axis through the first rotor wall and the second rotor wall and parallel to the axis of rotation (122); at least one first rotor magnet (372) coupled to the first rotor wall, the at least one first rotor magnet (372) configured to maintain a first space between the first rotor wall and the first stator magnet (362) along the rotor axis; at least one second rotor magnet (374) coupled to the second rotor wall, the at least one second rotor magnet (374) configured to maintain a second space between the second rotor wall and the second stator magnet (364) along the rotor axis; the at least one third rotor magnet (380) coupled to the sidewall (134) and spaced from one or more drive magnets (352) of the stator, the rotor (120) configured to be driven relative to the axis of rotation (122) by the drive magnets (352), the drive magnets (352) configured to emit the magnetic field in response to a control signal, and the magnetic field interacting with the at least one third rotor magnet (380) to drive the rotor (120), the one or more drive magnets configured to emit the magnetic field responsive to a control signal; characterized in that the rotor (120) further comprises a motor (1404) coupled to the annular rotor base (128), with a rotor blade (124, 126), and with a power receiving unit (1412), the motor receiving wireless power from a power transmission circuit (1410) from the stator to the power receiving unit (1412) to move the rotor blade to a desired pitch angle. 2. The system (300) of claim 1, further comprising: at least one rotor blade (124, 126) rotatably coupled with the sidewall (134) opposite the at least one third rotor magnet (380), the at least one rotor blade (124, 126) rotating about a blade axis extending transversely to the sidewall (134), wherein the at least one third rotor magnet (380) comprises a pair of third rotor magnets, the pair of third rotor magnets interacting with one or more drive magnets (352) via respective magnetic fields to produce rotation of the rotor blade about the blade axis (440). 3. System (300), according to claim 1, characterized by the fact that the rotor segments (132) are contiguous. 4. System (300) according to claim 1, characterized in that it further comprises: at least one rotating wheel (508) coupled to the rotor that extends between the rotor (120) and the stator (110) to separate the rotor (120) from the stator (110). 5. The system (300) of claim 1, wherein the at least one first rotor magnet (372) is aligned with the at least one second rotor magnet (374) along a magnet axis that extends parallel to the rotor axis and the rotation axis (122), wherein the magnet axis and the rotor axis are aligned. 6. System (300) according to claim 1, characterized in that the at least one first rotor magnet (372) and the at least one second rotor magnet (374) are permanent magnets. 7. The system (300) of claim 1, wherein the plurality of rotor segments (132) comprises a plurality of first rotor segments disposed around the stator, and wherein the annular rotor base (128) comprises a plurality of second rotor segments disposed around the stator (110) adjacent to the plurality of first rotor segments, wherein the plurality of first rotor segments are configured to rotate in a first direction about the axis of rotation (122) and wherein the plurality of second rotor segments are configured to rotate in a second direction about the axis of rotation (122) opposite to the first direction. 8. The system (300) of claim 1, wherein the rotor generates lift when driven by one or more propulsion magnets (352), while at least one first rotor magnet (372) maintains the first space and the at least one second rotor magnet (374) maintains the second space.