CN113734720B - Direct-drive multi-track flexible conveying system and control method thereof - Google Patents

Abstract

The invention discloses a direct-drive multi-track flexible conveying system and a control method thereof. The device comprises an annular base, a primary excitation type linear motor, a power supply module, a power driving module, a position detection module and a wireless communication module. The primary excitation type linear motor comprises a long stator and a plurality of rotors, wherein the long stator is formed by connecting iron cores of a multi-section tooth socket structure and is installed on an annular base, and the rotors comprise a short primary, a power driving module, a position detection module and a wireless communication module. The short primary is of a double-sided structure and is composed of a permanent magnet array, an armature winding and a primary iron core, wherein the permanent magnet array is of an asymmetric structure. The power supply module is composed of a power supply unit and a power receiving unit, and the power receiving unit is mounted on each mover. The annular base is composed of a plurality of annular bases, and the rotor can perform orbital transfer operation on different annular bases. The invention adopts the primary excitation type linear motor with high thrust density, the long stator has simple structure and low cost, all the rotors can completely and independently run, and the flexible conveying is carried out on different annular bases in an orbital transfer way.

Description

Direct-drive multi-track flexible conveying system and control method thereof

technical field

The invention belongs to a flexible conveying system and method in the technical field of flexible conveying systems, and particularly relates to a direct-drive multi-track flexible conveying system and a control method thereof.

Background technique

With the development of manufacturing technology towards precision, intelligence and flexibility, the demand for flexible conveying systems in industrial applications such as long-travel automated production lines, packaging and transportation logistics lines is increasing. Traditional conveying systems usually use rotating motors and mechanical components such as chains and belts to achieve linear transmission. The transmission efficiency is not high, and the reliability and control accuracy are low, and they do not have the basis for flexibility and intelligence. In recent years, in order to meet the requirements of precision, intelligence and flexibility in manufacturing technology, flexible conveying systems directly driven by permanent magnet linear motors have begun to be studied and applied. Permanent magnet linear motors have the advantages of both permanent magnet motors and linear motors. They can directly convert electrical energy into mechanical energy of linear motion without the need for intermediate mechanical transmission parts. They have significant advantages such as high thrust density, high speed, high precision and high efficiency. It can better meet the needs of flexible conveying systems.

The working principle of a traditional permanent magnet linear motor is as follows: when the armature winding is fed with alternating current, an armature magnetic field is generated in the air gap. At the same time, the permanent magnet poles generate an exciting magnetic field in the air gap. The armature magnetic field and the permanent magnet excitation magnetic field together constitute an air-gap magnetic field. When the motor starts, the magnetic pole is dragged, and the armature traveling wave magnetic field and the permanent magnet excitation magnetic field are relatively static, so that the current in the armature winding generates electromagnetic thrust under the action of the air gap magnetic field. If the armature is fixed, the magnetic poles will be pulled in synchronously to make linear motion under the action of thrust; otherwise, the armature will be pulled in synchronously to make linear motion.

Due to the long travel distance (usually tens of meters to hundreds of meters), a major constraint on the popularization and application of flexible conveying systems directly driven by traditional permanent magnet linear motors is cost. When the moving armature structure is used, the permanent magnets are used as long stators, which need to be laid in the entire motion range, and the amount of permanent magnets is very large; when the moving magnetic pole structure is used, the armature windings and iron cores are used as long stators, which need to be installed throughout the entire motion. It is laid within the range of travel, and the armature winding needs to be powered by multiple inverters in parallel, and the control is complicated. Therefore, whether a moving armature or a moving magnetic pole structure is adopted, the overall cost is high.

At present, some patents have proposed flexible conveying systems directly driven by traditional permanent magnet linear motors, such as patent numbers WO1996027544A1 (1996), US8996161B2 (2015), WO2015028212A1 (2015), EP3045399B1 (2017), US10112777B2 (2018), Patents such as US10181780B2 (2019), US10407246B2 (2019), WO2019007198A1 (2019), and US10773847B2 (2020) are all traditional permanent magnet linear motors using a moving magnetic pole structure, armature windings and iron cores as long stators. In order to greatly reduce the cost of the above-mentioned flexible conveying system directly driven by the traditional permanent magnet linear motor, the present invention innovatively proposes a flexible conveying system directly driven by the primary excitation type permanent magnet linear motor. Concentrate on the armature side as a short mover, while the secondary is only composed of a laminated core and acts as a long stator.

The existing primary excitation permanent magnet linear motors mainly have the following two types:

1. Switch flux linkage type permanent magnet linear motor

For example, the switching flux linkage type permanent magnet linear motor proposed by Chinese patents CN101355289B and CN108155775B, the topology structure clamps the permanent magnet in the middle of the armature core teeth, the amount of permanent magnet is small and the length of the armature is short. The stroke application can greatly reduce the cost, but it also brings new problems: (1) the armature core is composed of multiple discrete components, which is difficult to process and install; (2) the slot area and the permanent magnet are mutually restricted, and the thrust density is affected. (3) The permanent magnet is surrounded by the armature winding, and the heat dissipation conditions are poor.

2. Magnetic flux reversed permanent magnet linear motor

For example, the magnetic flux reversed permanent magnet linear motor proposed by Chinese patent CN101552535B, this topology places the permanent magnets on the surface of the armature core teeth close to the air gap. The amount of permanent magnets is small and the length of the armature is short. Long-stroke applications can greatly reduce costs, but it also brings new problems: because the magnetic circuits are connected in series, the armature magnetic circuit needs to pass through the permanent magnet, which makes the equivalent air gap of the armature magnetic circuit larger and the thrust density is limited.

The above two types of primary excitation type permanent magnet linear motors are symmetrical excitation structures, that is, the excitation magnetic fields generated by the permanent magnets of the two polarities are symmetrical to each other, so after the fast Fourier transform, there are only fundamental waves and odd-numbered waves. Harmonic magnetomotive force components, and there is no even-numbered harmonic magnetomotive force components. For the primary excitation type permanent magnet linear motor, which relies on the effective harmonic magnetic field to generate thrust, only relying on the fundamental wave and the odd-numbered harmonic magnetomotive force limits the further improvement of the thrust density of the motor.

SUMMARY OF THE INVENTION

Aiming at the technical problems of the high cost of the existing flexible conveying system and the limited thrust density of the existing primary excitation type permanent magnet linear motor, the present invention proposes an asymmetric multi-harmonic primary excitation type permanent magnet The flexible conveying system directly driven by the linear motor, by constructing the asymmetric excitation structure of the permanent magnet, can generate a higher amplitude harmonic magnetomotive force with twice the number of pole pairs under the same amount of permanent magnet, which can effectively improve the primary excitation type. Thrust density of permanent magnet linear motors. At the same time, the long stator used in the present invention is only composed of laminated iron cores, the structure is simple and the cost is low.

The technical scheme of the present invention is as follows:

1. A direct-drive multi-track flexible conveying system:

The system includes two or more annular bases and primary excitation type linear motors, each annular base is installed on the same horizontal plane, and the primary excitation type linear motor is installed on the annular side of the annular base; the primary excitation type linear motor includes The long stator and multiple movers operate independently of each other and there is no electromagnetic coupling. The mover is adsorbed on the long stator through magnetic attraction and leaves an air gap between the mover and the long stator; the adjacent ring bases There is a gap between the seats to accommodate the passage of a single mover, and the mover runs from one ring base to another at the gap where different ring bases are aligned in parallel; the long stator is fixed on the ring base, The stator core with multi-segment slot structure is arranged and seamlessly connected along the annular side of the annular base, the inner surface of the stator core is fixed on the annular side of the annular base, and the outer surface of the stator core is along the annular side of the annular base There are tooth slots in the annular direction; the mover includes the short primary and the roller guide rail assemblies on both sides, the short primary and the roller guide rail assemblies are fixedly connected together by the bracket, the short primary is located on the outer side of the long stator, and there is air between the short primary and the long stator. There are roller guide rail assemblies on both sides of the short primary. The roller guide rail assemblies include rollers and guide rails. The guide rails are laid along the annular direction of the annular base and parallel to the arrangement direction of the long stator and are fixed to the annular side of the annular base. Attached to the rail and moved along the rail. In this way, the mover is fixed on the guide rail through the roller, and moves on the guide rail through the roller.

The short primary and the long stator are maintained with an air gap under the interconnected support of the rollers and rails in the roller rail assembly.

The stator iron core is divided into a straight line segment arranged on the plane of the annular side surface of the annular base and an arc segment arranged on the arc surface of the annular side surface of the annular base. The inner diameter is the same as the outer diameter of the arc segment on the annular side of the annular base.

The short primary includes an asymmetrical permanent magnet array, an armature winding and a primary iron core, the middle of the primary iron core is a yoke, and the primary iron cores on both sides of the yoke are on the side facing the long stator and on the side away from the long stator. One side is provided with semi-closed slots, each side is provided with a plurality of semi-closed slots parallel to the arrangement direction of the long stator, and armature teeth are formed between adjacent semi-closed slots, that is, the primary iron core teeth, each armature tooth A coil is wound as the armature winding, that is, a coil is wound between two adjacent semi-closed slots where the armature teeth are located; the permanent magnet array is composed of a plurality of permanent magnet units closely arranged side by side and attached to the primary iron. On the surface of the core armature teeth, each permanent magnet unit is composed of permanent magnet A and permanent magnet B in a fixed order and side by side along any unidirectional arrangement parallel to the long stator. The width of the magnet B along the long stator arrangement direction is greater than the width of the permanent magnet A along the long stator arrangement direction, forming asymmetry; a permanent magnet B is arranged at the opening of each semi-closed slot, and the armature teeth of each semi-closed slot are outside A permanent magnet A is arranged on the end face.

The armature winding adopts a concentrated winding structure and is divided into upper and lower units. The upper unit of the armature winding is wound on the armature teeth on the upper side of the yoke of the primary iron core, and the lower unit of the armature winding is wound on the yoke of the primary iron core. On the armature teeth on the lower side of the armature, the upper and lower units of the armature winding are independently powered; when the mover is running on a single ring base, the armature winding unit close to the air gap side is separately powered; when the mover is on the two ring bases When the seat changes rails, the upper and lower units of the armature windings in the rail changing section are powered at the same time, and then the power supply unit of the armature windings on the side of the ring base that was originally running is powered off, and the armature windings on the side of the new ring base are powered off. Power on.

The magnetic pole directions of the permanent magnet A and the permanent magnet B are both along the depth direction of the cogging slot and perpendicular to the moving direction of the mover.

The primary iron core is a laminated iron core, and the lamination direction of the laminated iron core is perpendicular to the moving direction of the mover and parallel to the installation surface of the stator iron core of the long stator.

The number of the permanent magnet units is the same as the number of teeth of the primary iron core, and the number of teeth of the stator iron core of the long stator within the range of the length of a single mover is set to (kN _ph +2N _ph )±1, where kN _ph represents the primary iron core The number of teeth, k represents the slot number coefficient, and N _ph is the phase number of the permanent magnet linear motor.

The primary excitation type linear motor further includes a power supply module, and the power supply module is mainly composed of a power supply unit and a power receiving unit, and the power supply unit and the power receiving unit are respectively installed on the ring base and the mover;

The power supply unit is composed of two sliding contact lines of U-shaped structure. The lines are arranged side by side on both sides of the long stator, respectively forming a positive power line and a negative power line, and the end is connected to an external power supply;

The power receiving unit is composed of two current collectors including carbon brushes. The two current collectors are respectively slidably connected to the two sliding contact lines. The current collectors and the short primary and roller guide rail assemblies are fixed together by a bracket. In this way, the power supply unit and the power receiving unit are connected by sliding contact, and the electric energy can be transmitted to the mover in real time.

The current collector has elasticity, which ensures that the mover can be reliably connected with the sliding contact wire when the mover moves along the annular base, and the electric energy is transmitted to the mover in real time and reliably.

The primary excitation type linear motor further includes a position detection module. The position detection modules are all connected to the power receiving unit. The position detection module includes a passive magnetic scale laid along the long stator and a signal reading head integrated in the mover. The source magnetic scale is arranged along the annular direction of the annular base, parallel to the arrangement direction of the long stator and fixed to the annular side of the annular base. The signal reading head and the mover are fixedly installed together. The primary and roller guide rail assemblies are fixed together by a bracket, the signal read head is located on the side of the passive magnetic scale, and the signal read head and the passive magnetic scale cooperate for position detection.

The position detection module can detect the relative movement position of each movable sub-unit on the ring base in real time, and transmit the position signal to the power drive module.

The primary excitation type linear motor also includes a power drive module, a wireless communication module and a host computer. The power drive module, the wireless communication module and the mover are fixedly installed together. Specifically, the power drive module, the wireless communication module, the signal reading head, the set The electrical appliances, short primary, and roller guide rail components are fixed together by the bracket. The power drive module obtains electric energy from the power receiving unit and outputs three-phase alternating current to the armature winding of the short primary in the mover, which is used to drive the mover to move; The wireless communication module is connected with the upper computer, and the wireless communication module transmits the parameters of each mover detected and collected by the position detection module to the upper computer in real time, and receives the motion instructions issued by the upper computer.

The power drive module and the wireless communication module are all connected to the power receiving unit, and the power receiving unit supplies power to the power drive module, the position detection module and the wireless communication module integrated with the follower.

The power drive module includes a lithium battery energy storage unit, a hardware protection unit, a central control unit, a three-phase full-bridge silicon carbide inverter unit, and a signal acquisition and conditioning unit; the hardware protection unit is connected to the power receiving unit of the power supply module, and the hardware The protection unit is connected to the central control unit after the lithium battery energy storage unit. The hardware protection unit is respectively connected to the three-phase full-bridge silicon carbide inverter unit and the signal acquisition and conditioning unit. The central control unit is respectively connected to the three-phase full-bridge silicon carbide inverter. The unit, the signal acquisition and the conditioning unit are connected; the position detection module is connected with the central control unit, and the wireless communication module is connected with the central control unit.

The power drive module receives the position signal transmitted by the position detection module and the motion command transmitted by the wireless communication module, and thus generates three-phase PWM current to drive the mover to move.

The wireless communication module adopts a 5g communication module, which transmits the position, speed, voltage, current and other parameters of each mover to the host computer in real time, and receives the motion instructions issued by the host computer.

The power receiving unit of the power supply module, the signal reading head of the position detection module, the power drive module and the wireless communication module are integrated and installed around the short primary, and fixed on the bracket to move synchronously with the short primary.

2. A control method for a direct-drive multi-track flexible conveying system, which includes a collaborative control algorithm and a track-change control algorithm; the collaborative control algorithm includes the following steps:

Step 1: Parallel synchronization control is adopted between each mover, and the upper computer issues control instructions to each mover in parallel;

Step 2: According to the position signal feedback, the host computer monitors the real-time positions [P ₁ , P ₂ ,..., P _N ] of the N movers in real time, and calculates the running distance between the N movers [L ₁ , L according to the real-time positions] ₂ ,...,L _N ], where L ₁ represents the distance between the first mover and the second mover, L ₂ represents the distance between the second mover and the third mover, and L _N represents the Nth mover The distance between the first mover and the first mover;

Step 3: Compare and judge the relationship between the running distance [L ₁ , L ₂ , ..., L _N ] between the N movers and the minimum safe running distance L _s , when the k-th section running distance L _k is less than the minimum safe running distance Ls , to retrieve the running data of the kth and k+1th movers;

Step 4: According to the speed and position commands, judge the deviation of the actual running speed and position value of the kth and k+1th movers from the command value respectively. When the deviation is greater than the set threshold, it is determined that the mover has a fault. , the speed and position command values are re-issued to the mover, and the power drive module adjusts the output drive current to correct the motion state;

Step 5: Monitor the running data of the faulty mover. If the running distance between the faulty mover and the adjacent mover is still less than the minimum safe running distance L _s within ten control cycles, all the movers will be shut down in an emergency, and the faulty mover will be sent to the upper computer. fault signal;

The track change control algorithm includes the following steps:

Step 1: Set the position of the track-change segment mark on each ring base [P1 _on , P1 _off , P2 _on , P2 _off , ..., PN _on , PN _off ], where the numbers 1, 2 and N represent the first, For the 2nd and Nth ring bases, on represents the starting position of the track change segment, and off represents the end position of the track change segment. The track change segment is selected on the straight line segment of the annular base, and the start position and end position are set at the coincident position of the straight line segments of two adjacent annular bases;

Step 2: The host computer issues orbital instructions to each mover in parallel, and the orbital instructions include maintaining the operation on the current ring base, or changing the orbit to the adjacent ring base to run;

Step 3: After receiving the track command, each mover determines its real-time position [P ₁ , P ₂ ,..., P _N ] according to the position feedback signal, and judges its real-time position and the track-change section on the ring base where it is located. distance from the starting position [P1 _on , P2 _on , ..., PN _on ];

Step 4: For each mover that needs to be changed, after entering the starting position of the track changing section, the upper and lower units of the armature winding of the mover are powered at the same time, and then the power supply unit of the armature winding on the side of the ring base that was originally running is powered off. , and is powered by the armature winding on the side of the newly operating ring base;

Step 5: After changing the track, each mover feeds back the real-time position signal of the new ring base where it is located to the upper computer, and the upper computer monitors the running state of each mover.

The invention adopts the primary excitation type linear motor with high thrust density, the long stator has simple structure and low cost, and each mover can operate completely independently, and can be flexibly conveyed on different annular bases.

Compared with the prior art, the beneficial effects of the present invention are:

(1) The present invention adopts the direct drive of the primary excitation type permanent magnet linear motor, and concentrates the permanent magnet and armature with higher cost on one side of the armature as a short mover, while the secondary is only made of laminated iron with lower cost The core is constructed and used as a long stator, the system cost can be greatly reduced.

(2) The present invention adopts the permanent magnet asymmetric excitation structure, and can generate a harmonic magnetomotive force with a higher amplitude twice the number of pole pairs under the same amount of permanent magnets, and by reasonably selecting the number of secondary teeth, the fundamental wave can be balanced Magnetomotive force and second harmonic magnetomotive force can effectively improve the thrust density of the motor.

(3) Each mover of the present invention has an independent power supply module and a power drive module, there is no electromagnetic coupling between the movers, and can operate completely independently and realize flexible transportation with a high degree of freedom. The movable and stator adopts modular structure, which is convenient for processing and manufacturing, and can be flexibly configured according to actual needs.

(4) The mover of the present invention adopts a double-sided structure, which can realize the orbit-changing operation on different annular bases, and has a higher degree of freedom compared with the operation of a single annular base, and the orbit-changing operation relies on magnetic suction for switching, without the need for Complex mechanical track change structure.

Description of drawings

Figure 1 is a schematic structural diagram of a direct-drive multi-track flexible conveying system;

Figure 2 is a sectional view of a direct-drive multi-track flexible conveying system; (a) is a plan view of a direct-drive annular flexible conveying system, (b) is a cross-sectional view of A-A of (a), and (c) is an enlarged view of part B of (b) , (d) is the three-dimensional assembly drawing between the long stator and the mover;

Figure 3 is a schematic diagram of the structure of the straight segment and the arc segment of the long stator of the primary excitation type linear motor; (a) is a schematic diagram of the structure of the straight segment of the stator, (b) is a schematic diagram of the structure of the arc segment of the stator;

Figure 4 is a side view of a direct-drive multi-track flexible conveying system; (a) is a general view, (b) is a partial enlarged view;

Figure 5 is a schematic diagram of the structure of the primary excitation type linear motor mover; (a) is a left side view, (b) is a right side view;

6 is a schematic diagram of the electrical and signal connection of each module of the mover;

Figure 7 is a schematic diagram of a short primary structure of a primary excitation type linear motor; (a) is a plan view of the short primary, (b) is a cross-sectional view of the short primary;

Fig. 8 is a schematic diagram of a permanent magnet unit structure and magnetic field distribution;

Figure 9 is a comparison diagram of the air-gap flux density waveform and harmonic distribution under the slotless iron core of the stator; (a) is a comparison diagram of the air-gap flux density waveform, and (b) is a comparison diagram of the harmonic distribution;

Figure 10 is a short primary armature winding connection diagram;

Fig. 11 is a graph showing the variation of the sum of the amplitudes of the fundamental wave and the second harmonic with the ratio of the width of the permanent magnet;

Fig. 12 is a graph showing the variation of the sum of the effective harmonic amplitudes of each order with the ratio of the tooth width of the stator iron core under the modulation of the stator iron core;

Figure 13 is a graph showing the variation of the average thrust of the motor with the ratio of the tooth width of the stator core;

Figure 14 is a comparison diagram of the average thrust of the motor under asymmetric excitation and symmetrical excitation;

Fig. 15 is a block diagram of the cooperative control strategy among the movers;

Figure 16 is a schematic diagram of the running state of each mover;

Figure 17 is a schematic diagram of the minimum safe running distance between two movers;

Fig. 18 is a schematic diagram of the winding switching of the track changer operation of the mover.

In the figure: ring base 1, primary excitation linear motor 2, long stator 21, mover 22, guide rail 23A, roller 23B, straight segment 21A, arc segment 21B, power supply module 24, current collector 242, sliding contact line 241 , Power drive module 25, position detection module 26, passive magnetic scale 26A, signal reading head 26B, wireless communication module 27, short primary 28, permanent magnet array 281, armature winding 282, primary iron core 283.

Detailed ways

In order to describe the present invention in more detail, the technical solutions of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

FIG. 1 is a schematic structural diagram of the direct-drive multi-track flexible conveying system of the present embodiment, which mainly includes an annular base 1 and a primary excitation type linear motor 2 . In this embodiment, the annular base 1 is made of marble, and can also be made of aluminum profiles in practical applications. The multi-track flexible conveying system includes two or more annular bases 1, each annular base 1 is installed on the same horizontal plane, and the annular base 1 is annular. In this embodiment, a multi-track flexible conveying system including two annular bases is used as an example. The primary excitation type linear motor 2 is installed on the annular side surface of the annular base 1, and each annular base 1 is parallel and aligned on the same plane on the annular side surface on which the primary excitation type linear motor is installed, and there is space for air to accommodate the passage of the mover. The mover of the primary excitation type linear motor changes orbits from one annular base 1 to the other at the air gap where different annular bases are aligned in parallel. The primary excitation type linear motor 2 includes a long stator 21 and a plurality of movers 22. The movers operate independently of each other without electromagnetic coupling. The number of movers can be increased or decreased according to actual needs. At the same time, according to different application requirements, the mover 22 can be developed for the second time. After the installation holes are opened on the surface of the mover, it can be used to install different carrying equipment and transport articles of different specifications.

Figure 2 is a cross-sectional view of a direct-drive multi-track flexible conveying system. The long stator 21 is fixed on the annular base 1 and is formed by a stator core with a multi-segment cogging structure seamlessly connected, and includes a plurality of straight segments 21A and a plurality of arc segments 21B as shown in FIG. 3 . The stator core is provided with tooth slots on the side surface facing the mover, a plurality of tooth slots are arranged at intervals along the moving direction of the mover, and each tooth slot is arranged along the movement direction perpendicular to the mover, on the side facing away from the mover The surface is provided with threaded holes, and is fixed on the ring base with screws. The inner diameter of the stator core of the arc-shaped segment 21B on the side facing away from the mover is the same as the outer diameter of the annular arc-shaped segment of the annular base 1 . The mover 22 is fixed on the guide rail 23A by the roller 23B, and the guide rail 23A is laid along the long stator 21 and fixed to the annular base 1 . The mover 22 is adsorbed on the long stator 21 by magnetic attraction with an air gap, and moves on the guide rail by the roller. The size of the air gap between the mover and the long stator is set to 1-2 mm, and in this embodiment, the size of the air gap is 2 mm. In practical applications, considering the radius of the ring base, the length of the mover and the installation distance of the front and rear rollers, the choice of the air gap is restricted, that is, when choosing a smaller air gap to improve the thrust density of the motor, it is necessary to ensure that The mover in the shape of a straight segment can smoothly pass through the arc segment of the stator without jamming.

The power supply module 24 is composed of a power supply unit and a power receiving unit, and the power supply unit and the power receiving unit are respectively installed on the ring base 1 and the mover 22 . In this embodiment, the power supply unit on each annular base is composed of two U-shaped trolley wires 241, and the two trolley wires are arranged side by side on both sides of the long stator 21, and are fixed to the base. Sockets, respectively constitute positive and negative power lines, which are connected to an external power supply at one end. A power receiving unit is installed on each mover, and the power receiving units on the left and right sides of the mover 22 are each composed of two current collectors 242 including carbon brushes, and the two current collectors 242 are respectively arranged on both sides of the short primary 28 . The sliding contact connection between the current collector 242 and the sliding contact line 241 and the current collector 242 has elasticity, which can ensure that the mover is reliably connected with the sliding contact line 241 when the linear segment and the arc segment move, and the electric energy is transmitted to the sliding contact line 241 in real time and reliably. Mover 22. When the carbon brushes on the current collector 242 are severely worn, the entire current collector 242 can be replaced to ensure reliable connection with the trolley wire 241 . By means of sliding contact between the sliding contact wire and the current collector, the problem of cable connection when multiple movers are moving can be effectively avoided, and the cost of replacing the current collector is low. The position detection module 26 is composed of a passive magnetic scale 26A laid along the long stator and a signal reading head 26B integrated in the mover. The position detection module 26 feeds back the collected speed and position signals to the mover 22 in real time for use. drive control. In order to improve the positioning accuracy of the mover, the position detection module can use a grating ruler with higher accuracy.

Figure 4 is a side view of a direct-drive multi-track flexible conveying system. The two ring bases are mounted on the same level. The primary excitation type linear motor 2 is installed on the side of the ring base, and the two ring bases are aligned on the side where the primary excitation type linear motor is installed and there is an air gap for accommodating the passage of the mover, and the two ring bases are coincident. is the track change section. When the mover 22 is running in the track changing section, there are four rollers 23B on each side to support and run on the guide rails 23A. At this time, the power supply module 24 located on the side of the newly entered ring base starts to supply power to the mover 22 at the same time.

FIG. 5 is a schematic diagram of the structure of the primary excitation type linear motor mover. The main part of the mover 22 is composed of a short primary 28 . At the same time, four rollers 23B are installed on the left and right sides of the mover 22 to support the mover to be fixed on the guide rail 23A and maintain a certain air gap with the long stator 21 . It also includes a power drive module 25 , a wireless communication module 27 and a host computer, and the power drive module 25 , the wireless communication module 27 and the mover 22 are fixedly installed together. The power receiving unit, the signal reading head 26B of the position detection module, the power driving module 25 and the wireless communication module 27 are integrated and installed around the short primary 28 and move with it.

FIG. 6 is a schematic diagram of the electrical and signal connection of each module of the mover. The power driving module 25 obtains electric energy from the power receiving unit in real time, and stores a part of the electric energy in the lithium battery through the lithium battery energy storage unit. The three-phase full-bridge silicon carbide inverter unit inverts and outputs the direct current obtained from the power receiving unit into three-phase alternating current, which is used to drive the mover 22 to move. When the power receiving unit fails or is suddenly powered off, the lithium battery energy storage unit will be used to supply power to all modules on the mover 22 . In addition, the hardware protection unit will provide protection for overcurrent, short circuit and other faults of the short primary 28, and the signal acquisition and conditioning unit will condition the collected current, voltage, temperature and other signals and feed it back to the central control unit. The central control unit is the core of the power drive module, which is responsible for receiving the position signal transmitted by the position detection module and the motion command transmitted by the wireless communication module, and thereby generating a three-phase PWM signal to the three-phase full-bridge silicon carbide inverter unit for use. to drive the mover 22 to move. The wireless communication module can transmit the parameters of each mover to the host computer in real time, and receive the motion command issued by the host computer, and feed back the motion command to the power drive module.

7 is a schematic structural diagram of the short primary 28 of the primary excitation type linear motor, which includes an asymmetrical permanent magnet array 281 , an armature winding 282 and a primary iron core 283 . In this embodiment, the permanent magnet array 281 is composed of N _p =12 permanent magnet units closely arranged side by side and attached to the upper and lower surfaces of the armature teeth of the primary iron core 283 . The permanent magnet A and the permanent magnet B are formed by adhering side by side, and the permanent magnet A and the permanent magnet B have different widths and opposite polarities. Figure 8 shows a schematic diagram of the structure of the permanent magnet unit and the distribution of the magnetic field. It can be seen from the figure that when the permanent magnets A and B are asymmetrically distributed with different widths, the peaks of the magnetic fields of the permanent magnets A and B are not the same, and the main manifestations are as follows: The magnetic field amplitude is higher under the smaller width permanent magnet and lower under the larger width permanent magnet, and the positive and negative asymmetry of the amplitude will bring additional even harmonics that can be effectively utilized. Figure 9 shows the air gap flux density waveform and harmonic distribution under the stator slotless iron core of this embodiment. By introducing an asymmetric permanent magnet excitation structure, the permanent magnet magnetomotive force distribution in the motor can be changed from the original symmetrical type The odd-numbered multiple distribution is extended to the asymmetric integer multiple distribution. In the case of the same amount of permanent magnets, the even-numbered harmonic magnetomotive force with larger amplitude, especially the second harmonic magnetomotive force, can be additionally increased and effectively used. A new operating mode of multi-permanent magnetomotive force co-excitation.

Figure 10 shows the connection diagram of the short primary armature winding. The armature winding 282 adopts a single-layer concentrated winding. The upper and lower sides of the primary iron core 283 are wound with a coil every other armature tooth. The three-phase winding has a total of 12 coils. There is an electrical angle difference of 60 degrees between two adjacent coils on one side. The armature winding is divided into upper and lower units. The upper unit of the armature winding is wound on the teeth on the upper side of the yoke of the primary core, and the lower unit of the armature winding is wound on the teeth on the lower side of the yoke of the primary core. The upper and lower units of the pivot winding are powered independently. When the mover 22 runs on a single ring base, it is powered by the armature winding unit close to the air gap side; when the mover runs on the track-change sections of the two ring-shaped bases, the upper and lower units of the armature windings in the track-change section firstly supply power. At the same time, the power is supplied, and then the power supply unit of the armature winding on the side of the ring base in the original operation is de-energized, and the power is supplied by the armature winding on the side of the ring base in the new operation. At this time, after the mover 22 leaves the track changing section, the mover 22 enters a new annular base and starts to run due to the stronger suction on the energized side of the armature winding.

The primary iron core 283 is a laminated iron core with an integral punching type cogging structure, and the lamination direction of the laminated iron core is perpendicular to the moving direction and parallel to the installation plane of the stator iron core. The primary iron core is provided with a plurality of semi-closed slots on both sides of the yoke, the plurality of semi-closed slots are arranged at intervals along the movement direction, and the teeth of the primary iron core are formed between two adjacent semi-closed slots.

The arrangement of the long stators of the two ring-shaped base variable rail sections must meet the following requirements: the centerlines of the long stator core teeth on both sides are staggered by half the pole pitch along the moving direction to form an asymmetric structure, and the pole pitch refers to the long stator phase Periodic spacing between adjacent core teeth. The optimal number of stator core teeth satisfies the following relationship: when the number of primary core slots on one side is 2N _ph (N _ph is the number of phases), the optimal number of stator core teeth is 4N _ph ±1; When the number of core slots is 4N _ph , the optimum number of stator core teeth is 6N _ph ±1; when the number of primary core slots on one side is 6N _ph , the optimum number of stator core teeth is 8N _ph ±1. By analogy, the optimal number of teeth of the stator core is set to (kN _ph +2N _ph )±1, where kN _ph represents the number of teeth on one side of the primary iron core 283, k represents the slot number coefficient, and N _ph is the permanent magnet linear motor. Phase. In this embodiment, the number of phases used is 3 phases, and the number of teeth of the stator core is 17.

Table 1 shows the amplitude of the fundamental wave of the opposite electromotive force under different stator core teeth. It can be seen from Table 1 that when the number of teeth of the stator core is 17, the amplitude of the fundamental wave of the opposite electromotive force is the largest, while the number of teeth of the stator core is 19. Volatility is next. With the reduction of the number of stator core teeth, the amplitude of the fundamental wave of the opposite electromotive force also decreases. The amplitude of the fundamental wave when the stator core teeth are 13/14 close to the slot-pole fit is smaller than that when the stator core teeth are 17/19. The main reason is that the close-slot-pole coordination with a small number of stator core teeth cannot efficiently utilize the second harmonic magnetomotive force. With the increase of the number of teeth of the stator core, the amplitude of the fundamental wave of the opposite electromotive force decreases more obviously. It can be seen from this that, in order to effectively utilize the fundamental wave magnetomotive force and the second harmonic magnetomotive force at the same time, the coordination between the number of primary iron core slots and the number of teeth in the stator core breaks through the "near-slot coordination" in the traditional symmetrical excitation. The number of core teeth seeks a balance between the number of fundamental wave pole pairs and twice the number of harmonic pole pairs, and the optimal number satisfies the above-mentioned relationship.

Table 1 Amplitude of fundamental wave of opposite electromotive force under different stator core teeth number

Number of stator core teeth 13 14 16 17 19 20 twenty two twenty three Amplitude of opposite electromotive force fundamental wave (V) 32.4 33.2 35.1 38.6 37.8 29.1 26.3 23.5

After determining the optimal number of stator core teeth, the optimal setting method based on analytic function can be used to quickly optimize the setting of the optimal ratio of the permanent magnet width and the optimal ratio of the stator core tooth width for the primary excitation type permanent magnet linear motor. , the steps are as follows:

Step 1: In the case of setting the stator without teeth and cogging, establish an analytical model of the slotless air-gap magnetic flux density of the asymmetric excitation pole under the coggingless structure of the stator, which is expressed as:

Among them, x represents the distance that the short primary moves along the moving direction, B _slotless (x) represents the slotless air gap magnetic flux density, α represents the ratio of the width of the permanent magnet A to the total width of the permanent magnet unit, and i represents the harmonic multiple of each order , g represents the air gap between the mover and the stator, B _r represents the remanence of the permanent magnet, μ _r represents the relative permeability of the permanent magnet, h _m represents the thickness of the permanent magnet in the direction of magnetization, and l _p represents the Periodic slot spacing between adjacent semi-closed slots;

Step 2: Calculate the air gap magnetic flux density B _slotless (x) when the number of pole pairs is equal to the number of teeth N _p of the primary core as the fundamental wave amplitude, and calculate the number of pole pairs equal to twice the number of teeth N of the primary core 11 on one side of the core The air gap magnetic flux density B _slotless (x) at _p is used as the second harmonic amplitude, and the maximum sum of the fundamental wave amplitude and the second harmonic amplitude is taken as the optimization goal, and the width of the permanent magnet A is obtained by the optimization solution. The ratio α of the total width of the magnetic unit;

Step 3: In the case of setting the stator with teeth and cogging slots, establish an analytical model of stator permeability, which can be expressed as:

Among them, t represents time, Λ _s (x, t) represents the permeability function when the short primary moves a distance x along the motion direction at time t, Λ _s0 represents the 0-order permeability value, and Λ _s1 represents the 1-order permeability value , N _s represents the number of teeth of the stator in the same length range as the short primary, N _p represents the number of slots of the short primary, V _s represents the moving speed of the short primary relative to the long stator, x _s0 represents the initial position of the short primary relative to the long stator , w _st represents the tooth width of the long stator iron core teeth, τ represents the distance between two adjacent teeth of the long stator iron core, and β represents the variation coefficient;

Step 4: Obtain the ratio α of the width of the permanent magnet A to the total width of the permanent magnet unit according to step 2, and substitute it into the slotless air-gap magnetic flux density analytical model of the asymmetric excitation poles under the stator slotless structure, and then combine the stator permeability analysis The model is substituted into the following analytical model of the air-gap magnetic flux density of the asymmetrical excitation poles under the cogging structure of the stator, and the air-gap magnetic flux density is obtained by solving:

Among them, B _slotted (x, t) represents the air-gap magnetic flux density of the asymmetric excitation pole with cogging structure when the short primary moves a distance x along the motion direction at time t, and μ ₀ represents the vacuum permeability.

Step 5: Calculate the sum of the air-gap magnetic flux densities under different pole pairs according to the formula in step 4, and then sum up the sum of the fast Fourier transform, and take the maximization of the sum of the above air-gap magnetic flux densities as the goal, and optimize the solution to obtain The tooth width of a single stator is used as the optimal value, and then the optimal setting of the primary excitation type permanent magnet linear motor is completed.

Figure 11 shows the change of the sum of the amplitude of the fundamental wave and the second harmonic with the ratio of the width of the permanent magnet. It can be seen from the figure that the results obtained by the fast calculation method based on the analytic function are consistent with the results based on the finite element calculation. , the specific value is slightly different. At the same time, when the ratio α of the width of the permanent magnet A to the total width of the permanent magnet unit is about one-third, the sum of the amplitudes of the fundamental wave and the second harmonic is the largest, and the ratio can be set to the maximum Excellent ratio.

On this basis, the air-gap magnetic flux density is solved by using the air-gap magnetic flux density analytical model of the asymmetrical excitation magnetic poles under the cogging structure of the stator obtained in step 4, and the fast Fourier transform of the air-gap magnetic flux density after the solution is carried out. Transform to obtain the amplitude of the air gap magnetic flux density under different pole pairs, sum the pole pairs of |12i±17|, i=1, the amplitude of the second harmonic, and use the amplitude of the above harmonic The goal is to maximize the sum of the values, and the optimal ratio of the stator core tooth width is optimized to obtain the optimal value. Figure 12 shows the variation of the sum of the effective harmonic amplitudes with the tooth width ratio of the stator iron core under the modulation of the stator iron core. It can be seen from the figure that the results obtained by the fast calculation method based on the analytic function are different from those obtained by the finite element calculation method. The results show the same trend, with slight differences in specific values. When the ratio of the stator core tooth width to the stator pole pitch is about one-third, the sum of the 5th, 7th, 29th and 41st harmonic amplitudes is the largest. At this time, the ratio can be set as the optimal ratio.

Figure 13 shows the variation of the average thrust of the motor with the ratio of the teeth width of the stator core. It can be seen from the figure that the variation trend of the average thrust with the ratio of the teeth width of the stator core and the sum of the effective harmonic amplitudes vary with the teeth of the stator core. The wide variation trend is consistent. It can be seen from this that the optimal setting method based on the analytic function can quickly optimize the setting of the optimum ratio of the width of the permanent magnet and the optimum ratio of the tooth width of the secondary iron core, which can achieve the goal of optimizing and improving the thrust density of the motor, and Quickly achieve optimal settings for key parameters.

Figure 14 shows the comparison chart of the average thrust of the motor under asymmetric excitation and symmetric excitation, in which the optimal slot-pole combination used for asymmetric excitation is 12 slots and 17 poles, and the optimal slot-pole combination used for symmetrical excitation is 12 slots. 14 poles. It can be seen from the figure that under the same copper consumption and permanent magnet dosage, by changing the width ratio of the permanent magnets, the average thrust under asymmetric excitation can be increased by about 38.1% compared with that under symmetrical excitation, and the thrust density of the motor is greatly improved. It can be seen from this that the primary excitation type permanent magnet linear motor with asymmetric excitation and its optimal setting method proposed by the present invention can effectively improve the thrust density of the motor.

After the hardware part of the above-mentioned direct-drive multi-track flexible conveying system is completed, the multi-movers can be driven and controlled to ensure that each mover can operate relatively independently and efficiently. Figure 15 shows the block diagram of the cooperative control strategy among the movers. Parallel synchronous control is adopted between the movers. The upper computer sends control commands to each mover in parallel, and the wireless communication module transmits the control commands to the power drive module after receiving them. The central control unit in the power drive module performs feedback control according to the actual operating conditions of the mover and control commands, and thus generates a three-phase PWM signal to the three-phase full-bridge silicon carbide inverter unit for driving the mover to move. Parallel synchronization control can ensure that each mover maintains a certain degree of independence while operating in coordination, and avoids the interference of the entire system operation caused by the operation error of a single mover.

Fig. 16 is a schematic diagram showing the running state of each mover. According to the position signal feedback, the host computer monitors the real-time positions of N movers in real time and expresses it as [P ₁ , P ₂ ,...,P _N ]. According to the real-time position [P ₁ ,P ₂ ,…,P _N ], the running distance [L ₁ ,L ₂ ,…,L _N ] between N movers can be calculated, where L ₁ represents the first mover and the The distance between the second mover, L ₂ is the distance between the second mover and the third mover, L _k is the distance between the k-th mover and the k+1-th mover, L _N is the distance between the k-th mover and the k+1-th mover The distance between the Nth mover and the first mover.

Figure 17 shows a schematic diagram of the minimum safe running distance between the two movers. Under the parallel synchronous control strategy, each mover has a certain distance in the front and rear directions of operation, which can be used to adjust the operating state during feedback control. In the safe activity area, there is no possibility of collision between the movers, so the system can run safely, and each mover adjusts its own operating state according to the control instructions. During the running process, the host computer compares and judges the relationship between the running distance [L ₁ , L ₂ , ..., L _N ] between the N movers and the minimum safe running distance Ls in real time. When the k-th running distance L _k is less than the minimum safe running distance L _s , the k-th and k+1-th movers have abnormal running states, and the k-th and k+1-th movers need to be called for the operation data.

According to the speed and position commands, the deviation of the actual running speed and position value of the kth and k+1th movers from the command value is judged respectively. When the deviation is greater than the set threshold, it is determined that the mover has a fault, and the The mover re-issues speed and position command values, and the power drive module adjusts the output drive current to correct the motion state. The upper computer continues to focus on monitoring the operation data of the faulty mover. If the running distance from the adjacent mover is still less than the minimum safe running distance L _s within ten control cycles, all movers will be shut down in an emergency, and the faulty mover will be sent to the upper computer. Send a fault signal.

The direct-drive multi-track flexible conveying system can realize the track-change operation by controlling the on-off of the upper and lower units of the short primary armature winding in the mover 22 . First, set the position of the track-change segment mark on each ring base [P1 _on , P1 _off , P2 _on , P2 _off , ..., PN _on , PN _off ], where the numbers 1, 2 and N represent the first and second respectively. 2 and the Nth ring base, on represents the start position of the track change segment, off represents the end position of the track change segment. The track change segment is selected on the straight line segment of the annular base, and the starting position and the ending position are set at the coincident position of the straight line segments of two adjacent annular bases. Orbital commands are issued by the host computer to each mover in parallel. The orbital commands include two types of operation: maintaining the current ring base, or changing the track to the adjacent ring base. After the mover receives the orbit command, each mover determines its real-time position [P ₁ , P ₂ ,..., P _N ] according to the position feedback signal, and judges that its real-time position starts from the orbit change section on the ring base. The distance from the starting position [P1 _on , P2 _on , ..., PN _on ] to prepare for the track change operation.

Fig. 18 shows a schematic diagram of the winding switching of the track-change operation of the mover, which can be divided into three operating states. State 1: For each mover that needs to change rails, when just entering the starting position P _on of the rail changing section, the original power supply unit of the armature winding of the mover 22 still maintains power supply to ensure that the mover 22 runs stably on the long stator; state 2: When the mover 22 completely enters the rail changing section, the new power supply unit of the armature winding starts to supply power, and the amplitude and phase of the three-phase current in the new armature winding refer to the original power supply unit of the armature winding; state 3: when the armature winding After the upper and lower power supply units of the windings supply power stably at the same time and the mover 22 operates stably, the original power supply unit of the armature winding is powered off, and the power is supplied by the armature winding power supply unit on the side of the newly operating ring base. At this time, after the mover 22 leaves the track changing section, the mover 22 enters a new annular base and starts to run due to the stronger suction on the energized side of the armature winding. After changing the track, each mover feeds back the real-time position signal of the new ring base to the upper computer, and the upper computer monitors the running state of each mover.

The above description of the embodiments is for the convenience of those of ordinary skill in the art to understand and apply the present invention. It will be apparent to those skilled in the art that various modifications to the above-described embodiments can be readily made, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above-mentioned embodiments, and improvements and modifications made by those skilled in the art according to the disclosure of the present invention should all fall within the protection scope of the present invention.

Claims (9)

1. The utility model provides a flexible conveying system of direct-drive formula multitrack which characterized in that:

the system comprises two or more annular bases (1) and primary excitation type linear motors (2), wherein each annular base (1) is arranged on the same horizontal plane, and the primary excitation type linear motors (2) are arranged on the annular side surfaces of the annular bases (1); the primary excitation type linear motor (2) comprises a long stator (21) and a plurality of movers (22), wherein the movers (22) operate independently and do not have electromagnetic coupling, the movers (22) are adsorbed on the long stator (21) through magnetic attraction, and air gaps are reserved between the movers (22) and the long stator (21); gaps for accommodating the single rotor (22) to pass are reserved between the adjacent annular bases (1), and the rotor (22) performs track transfer operation from one annular base (1) to the other annular base (1) at the gaps where the different annular bases (1) are aligned in parallel;

the long stator (21) is fixedly connected to the annular base (1) and is formed by arranging stator cores of a multi-section tooth space structure along the annular side face of the annular base (1) and connecting the stator cores in a seamless mode, the inner surface of each stator core is fixed on the annular side face of the annular base (1), and tooth spaces are formed in the outer surface of each stator core along the annular direction of the annular base (1);

the rotor (22) comprises a short primary (28) and a roller guide rail assembly, the short primary (28) and the roller guide rail assembly are fixedly connected together through a support, the short primary (28) is located on the outer side of the long stator (21), an air gap is reserved between the short primary (28) and the long stator (21), the roller guide rail assembly is arranged on each of two sides of the short primary (28) and comprises a roller (23B) and a guide rail (23A), the guide rail (23A) is laid and fixedly connected to the annular side face of the annular base (1) along the annular direction of the annular base (1) and in parallel with the arrangement direction of the long stator (21), and the roller (23B) is connected to the guide rail (23A) and moves along the guide rail;

under the mutual connection support of a roller (23B) and a guide rail (23A) in the roller guide rail assembly, a short primary (28) and a long stator (21) are kept to have an air gap;

the short primary (28) comprises a permanent magnet array (281), an armature winding (282) and a primary iron core (283) which are in asymmetric structures, the middle part of the primary iron core (283) is a yoke part, the primary iron core (283) on two sides of the yoke part is provided with semi-closed slots on one side facing the long stator (21) and one side far away from the long stator (21), each side is provided with a plurality of semi-closed slots at intervals along the arrangement direction parallel to the long stator (21), armature teeth are formed between adjacent semi-closed slots, and each armature tooth is wound with a coil to be used as the armature winding (282);

the permanent magnet array (281) is formed by a plurality of permanent magnet units which are closely arranged side by side and are attached to the surface of the armature teeth of the primary iron core (283), each permanent magnet unit is formed by fixing a permanent magnet A and a permanent magnet B which are sequentially attached side by side along any one direction which is parallel to the long stator (21), the polarities of the permanent magnet A and the permanent magnet B are opposite, and the width of the permanent magnet B along the arrangement direction of the long stator (21) is larger than that of the permanent magnet A along the arrangement direction of the long stator (21), so that asymmetry is formed; a permanent magnet B is uniformly arranged at the opening of each semi-closed slot, and a permanent magnet A is arranged on the outer end face of the armature tooth of each semi-closed slot;

the armature winding (282) is of a concentrated winding structure and is divided into an upper unit and a lower unit, the upper unit of the armature winding is wound on the armature teeth on the upper side of the yoke part of the primary iron core (283), the lower unit of the armature winding is wound on the armature teeth on the lower side of the yoke part of the primary iron core (283), and the upper unit and the lower unit of the armature winding supply power independently.

2. A direct drive multiple track flexible conveyor system according to claim 1, wherein:

the stator core divide into straightway (21A) of arranging on the plane of annular side of annular base (1) and segmental arc (21B) of arranging on the cambered surface of annular side of annular base (1), segmental arc (21B) the same with the segmental arc external diameter of annular side of annular base (1) the arc internal diameter of stator core.

3. A direct drive multiple track flexible conveyor system according to claim 1, wherein:

the primary core (283) adopts a laminated core, and the lamination direction of the laminated core is vertical to the moving direction of the rotor (22) and parallel to the stator core mounting surface of the long stator (21).

4. A direct drive multiple track flexible conveyor system according to claim 1, wherein:

the number of the permanent magnet units is the same as the number of teeth of the primary iron core, and the number of teeth of the stator iron core of the long stator (21) in the length range of a single rotor is set to be (kN)_ph+2N_ph) +/-1, where kN_phDenotes the number of teeth of the primary core (283), k denotes the slot number coefficient, N_phThe number of phases of the permanent magnet linear motor.

5. A direct drive multiple track flexible conveyor system according to claim 1, wherein: the primary excitation type linear motor (2) further comprises a power supply module (24), the power supply module (24) mainly comprises a power supply unit and a power receiving unit, and the power supply unit and the power receiving unit are respectively installed on the annular base (1) and the rotor (22); the power supply unit is composed of two sliding contact lines (241) of a U-shaped structure, each sliding contact line is arranged along the annular direction of the annular base (1) and parallel to the arrangement direction of the long stator (21) and fixedly connected to the annular side face of the annular base (1), the two sliding contact lines are arranged on two sides of the long stator (21) side by side respectively to form a positive power line and a negative power line respectively, and the end parts of the two sliding contact lines are externally connected with a power supply; the power receiving unit is composed of two current collectors (242) including carbon brushes, and the two current collectors (242) are respectively connected to two trolley lines (241) in a sliding contact manner.

6. A direct drive multiple track flexible conveyor system according to claim 1, wherein:

primary excitation type linear electric motor (2) still include position detection module (26), position detection module (26) are including passive magnetic grid chi (26A) and signal reading head (26B), passive magnetic grid chi (26A) are along the circumferencial direction of annular base (1), be on a parallel with long stator (21) and arrange the annular side of direction arrangement and rigid coupling in annular base (1), signal reading head (26B) and active cell (22) fixed mounting together, signal reading head (26B) are located passive magnetic grid chi (26A) side, signal reading head (26B) and passive magnetic grid chi (26A) cooperation carry out position detection.

7. A direct drive multiple track flexible conveyor system according to claim 1, wherein:

the primary excitation type linear motor (2) further comprises a power driving module (25), a wireless communication module (27) and an upper computer, the power driving module (25), the wireless communication module (27) and the rotor (22) are fixedly mounted together, the power driving module (25) obtains electric energy from a power receiving unit and outputs three-phase alternating current to an armature winding (282) of a middle-short primary (28) of the rotor (22) for driving the rotor (22) to move; the position detection module is connected with the upper computer through the wireless communication module, and the wireless communication module (27) transmits each mover parameter detected and collected by the position detection module to the upper computer in real time and receives a motion instruction sent by the upper computer.

8. A direct drive multiple track flexible conveyor system according to claim 5, wherein:

the power receiving unit of the power supply module (24), the signal reading head (26B) of the position detection module (26), the power driving module (25) and the wireless communication module (27) are integrally installed around the short primary (28) and fixed on the support to synchronously move along with the short primary (28).

9. The control method applied to the direct-drive multi-track flexible conveying system of any one of claims 1 to 8, which comprises a cooperative control algorithm and a track change control algorithm; the cooperative control algorithm comprises the following steps:

the method comprises the following steps: the rotors (22) adopt parallel synchronous control, and an upper computer issues control instructions to the rotors in parallel;

step two: according to positionThe upper computer monitors the real-time positions [ P ] of the N movers (22) in real time by feeding back the position signals₁,P₂,…,P_N]Calculating the running distance [ L ] between N movers according to the real-time position₁,L₂,…,L_N]Wherein L is₁Denotes the distance between the first mover and the second mover, L₂Denotes the distance, L, between the second mover and the third mover_NRepresenting the distance between the Nth mover and the first mover;

step three: comparing and judging the running distance [ L ] between N rotors₁,L₂,…,L_N]Distance L from minimum safe operation_sWhen the k-th section runs a distance L_kWhen the minimum safe operation distance Ls is less than the minimum safe operation distance Ls, operation data of the kth mover and the kth +1 mover are called;

step four: according to the speed and position instructions, the deviations of the actual operation speed and position values of the kth mover and the k +1 th mover and the instruction values are respectively judged, when the deviations are larger than a set threshold value, the mover is determined to have a fault, the speed and position instruction values are issued again to the mover, and the power driving module adjusts the output driving current to correct the motion state;

step five: monitoring the operation data of the fault rotor, and if the operation distance between the fault rotor and the adjacent rotor is still less than the minimum safe operation distance L in ten control periods_sAll the rotors are stopped emergently, and the fault rotor sends a fault signal to the upper computer;

the track transfer control algorithm comprises the following steps:

the method comprises the following steps: setting track change mark position [ P1 ] on each annular base_on，P1_off，P2_on，P2_off，…,PN_on,PN_off]Wherein the numbers 1,2 and N denote the 1 st, 2 nd and nth annular bases, respectively, on denotes the start position of the track segment and off denotes the end position of the track segment; the track transfer section is selected from straight line sections of the annular base, and the starting position and the ending position are arranged at the superposition position of the straight line sections of two adjacent annular bases;

step two: an upper computer sends track instructions to each rotor in parallel, wherein the track instructions comprise operation of the existing annular base or operation of the adjacent annular base after track change;

step three: after receiving the track instruction, each rotor determines its real-time position [ P ] according to the position feedback signal₁,P₂,…,P_N]And judging the real-time position of the track changing section and the initial position of the track changing section on the annular base [ P1 ]_on，P2_on，…,PN_on]The distance of (d);

step four: for each rotor needing to be subjected to orbital transfer, after the rotor enters an orbital transfer section initial position, the upper unit and the lower unit of an armature winding of the rotor supply power simultaneously, then the armature winding power supply unit on the side of the ring-shaped base which operates originally is powered off, and the armature winding on the side of the ring-shaped base which operates newly supplies power;

step five: after the orbit is changed, the rotors feed back real-time position signals of the new annular base to the upper computer, and the upper computer monitors the running state of each rotor.

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