CN111890410A - A drive-control integrated collaborative robot joint with running status monitoring function - Google Patents

Abstract

The invention discloses a drive-control integrated collaborative robot joint with running state monitoring function, comprising a joint shell, a permanent magnet synchronous motor, a harmonic reducer, a motor end encoder, an output end encoder, a brake, a driver and the like. In the present invention, the harmonic reducer is driven to rotate by the permanent magnet synchronous motor, and the output end encoder is placed behind the output return shaft. The motor end integrates a flat power-off permanent magnet protection brake, which can brake the joint and maintain the posture in an emergency. The back end of the joint integrates the driver and controller. The mechanical structure design integrating the motor output spindle and the wave generator can effectively reduce the joint mass, simplify the joint structure and increase the structural rigidity. The wiring method of hollow wiring can realize 360° continuous rotation of the joint motor. Adopt CAN bus communication mode, can realize multi-joint communication control. The invention effectively increases joint integration, positioning accuracy and stability, reduces joint mass and simplifies wiring.

Description

A drive-control integrated collaborative robot joint with running status monitoring function

technical field

The invention relates to the technical field of robots, and more particularly, to a drive-control integrated collaborative robot joint with a function of running state monitoring.

Background technique

With the development of collaborative robot technology, higher requirements are also put forward for its core components. Collaborative robot joints are the core components of robot motion. Modular, lightweight and high-precision integrated robot joints are the development trend of robot joints. Collaborative robots have proposed joint modules due to their own characteristics, such as miniaturization, light weight, large torque-to-weight ratio, high precision, and highly integrated joint modules. With the development of integrated technology, the requirement of integrated drive and control is also put forward for collaborative robot joints to reduce the difficulty of using collaborative robot joints in robots.

Traditional robot joints mostly use a simple combination of reducers and motors, which cannot be highly integrated. The joints lack core components or redundant components, and most joints do not integrate and reduce components according to the characteristics of collaborative robots. Traditional collaborative robot joints can be divided into reduction box joints, planetary reducer joints, and harmonic reducer joints according to the deceleration principle. Gearbox type joints and planetary reducer joints have the advantages of low cost and simple design structure, but it is not easy to achieve a hollow wiring structure in the construction of robots, and the reduction ratio is low and cannot be used under large torque. The harmonic reducer joint can better meet the requirements of collaborative robots. Traditional collaborative robot joints use harmonic reducer housings, output encoder housings, output flanges, adapter mounts or flanges, multiple bearing mounts, couplings, brake mounts, etc. . The structure is complex and the volume is large.

According to the requirements of the national standard GB11291, collaborative robots need to meet the ability of hazard recognition. As the core driving hardware of collaborative robots, robot joints need to meet the ability of emergency braking. Robot joints with special flat, small volume and large aperture robot joint brakes can maximize Good to meet the requirements of national standards. Existing robot joints mostly use chuck-type, pin-type, and general-purpose brakes. The chuck-type and pin-type brakes have braking gaps and cannot achieve complete positioning. The general-purpose permanent magnet brakes have small diameters, excessive braking torque, and The mass and volume are too large and cannot well meet the requirements of the collaborative robot for shutdown quality.

As mentioned above, the traditional collaborative robot joints have the following problems: complex and heavy structure, huge volume; insufficient integration, no shared structure between parts; lack of key components in the collaborative robot joint set, such as brakes, output encoders, drives controller etc.

SUMMARY OF THE INVENTION

According to the characteristic requirements of the collaborative robot, the invention adopts a single shell design, an integrated main shaft design of the motor spindle and the wave generator, integrates dual encoders, and adopts a flat special permanent magnet power-off brake, which can better meet the national standards and cooperation. Robot performance requirements.

The purpose of the present invention is to overcome the above-mentioned shortcomings of the existing technology, solve the problem of complex structure of the traditional brake, simplify the structure and reduce the connecting parts and fixing parts, so as to simplify the joint and reduce the weight; At the same time, the shutdown volume is reduced, the drive and control are integrated, and the torque sensor mounting flange and hollow wiring structure are reserved. The torque sensor can be installed at the end or any joint as required.

In order to solve the technical problem, the technical scheme adopted by the present invention is:

A drive-control integrated collaborative robot joint with running state monitoring function, comprising a shell, a harmonic reducer, a magnetic synchronous motor, a harmonic reducer, a motor end encoder, an end encoder, a temperature sensor, a brake, a driver, Joint main shaft, end return shaft, sealed bearing and oil seal. Harmonic reducer, magnetic synchronous motor, harmonic reducer, motor end encoder, end encoder, temperature sensor, brake, driver, joint spindle, end return shaft, sealed bearing and oil seal are all integrated in the housing. Through the end return shaft, the speed information is transmitted to the encoder inside the housing. The drive controller is integrated at the end of the joint.

The invention adopts a single shell design method, the main bearing fixing part and the shell are designed into an integrated structure, the harmonic reducer is fixed on the shell through the flange, and the steel wheel fixing method is adopted; the permanent magnet synchronous motor is fixed on the shell by gluing In the housing motor compartment; the harmonic reducer wave generator and the motor spindle are designed as an integral structure. The main bearing, motor rotor, brake rotor, incremental encoder rotor, skeleton oil-sealed rotor are installed on the main shaft, and the main shaft is fixed on the harmonic reducer. Inside and through the motor stator, it is fixed in the shell through the front and rear bearings; the return shaft is fixed on the flex wheel of the harmonic reducer, and returns to the inside of the shell through the hollow spindle, and the absolute encoder rotor is installed on the return spindle; the encoder stator mounted on the housing.

Further, the shell of the joint is made of aviation aluminum alloy.

Further, the power component includes a permanent magnet synchronous motor and a harmonic reducer; the permanent magnet synchronous motor and the harmonic reducer are connected by an integrated main shaft, and the main shaft is a mechanical structure shared by the harmonic wave generator and the permanent magnet synchronous motor rotor. . The harmonic reducer is directly connected to the housing by the rigid wheel fixing method, the permanent magnet synchronous motor stator is fixed in the housing motor compartment by gluing, and the main shaft uses two sealed bearings to connect with the end flange and the housing bearing method. Lan fixed.

Further, the integrated design of the main shaft and the main shaft of the harmonic reducer reduces the number of fixed parts and shortens the length of the main shaft. The two ends of the main shaft are fixed by bearings, and the bearing fixing flanges are installed in the housing.

Further, the speed measuring assembly of the present invention includes two encoders, which are an absolute encoder at the end and an incremental encoder at the motor end. The incremental encoder at the motor end is directly fixed on the joint spindle, and the end output encoder is fixed on the return shaft of the end output flange. One end of the return shaft is fixed on the end output flange through the flange, and the other end is fixed inside the housing. on the support bearing.

Further, the brake adopts a flat large-diameter permanent magnet power-off brake, which is fixed on the bearing flange. If the joint loses power or receives a braking command during operation, the principle of friction braking will be used to lock the spindle for braking.

Further, the drive controller adopts a circular structure and integrates the driver and the controller. The driver also has CAN bus communication, serial communication, and WIFI wireless communication, as well as a temperature sensor and a vibration sensor. CAN communication has the characteristics of strong real-time data communication between nodes in the network. Multiple robot joints can communicate with the host computer through CAN bus connection. The connection method is shown in Figure 6. The joint can transmit the rotational speed of the joint, Current, position, temperature, and vibration information can be used with the host computer for secondary development of operation detection and data processing as needed. The schematic diagram of WIFI information transmission is shown in Figure 7.

Further, 360° continuous rotation can be achieved through the hollow shaft.

The invention highly integrates harmonic reducers, permanent magnet synchronous motors, encoders, brakes, drivers, controllers, sensors, etc., can be quickly installed through flanges, used in series through a bus, and has broad application prospects.

Compared with the prior art, the present invention has the following beneficial effects:

The present invention adopts the integrated design of the shared mechanical structure, adopts the design method that the harmonic motor shares one main shaft, and installs the return shaft bearing fixed part in the brake, which effectively reduces the length of the joint, and does not cut down the key compared with the traditional electromechanical actuator. The premise of the component has a flatter structure.

On the basis of meeting the performance requirements, the present invention omits the harmonic shell, the coupling or shaft connecting flange, the main shaft bearing fixing part, and the sealing bearing at the input end of the harmonic reducer, and adopts the skeleton oil seal to seal the lubricating oil. . The dual encoder central control wiring structure is adopted, and the encoder at the rear output end is directly fixed on the joint housing, omitting the encoder fixing part. Effectively reduce joint volume and weight.

The design of the high-precision output absolute encoder and the harmonic motor sharing one main shaft effectively increases the absolute positioning accuracy and repeatable positioning accuracy.

The flat and large-diameter permanent magnet power-off brake can effectively increase the braking accuracy. Compared with the traditional permanent magnet brake, the space in the casing is effectively used, and the joint is flatter.

Description of drawings

Figure 1. Sectional view of the robot joint.

Figure 2. External structure diagram of the robot joint.

Figure 3. Schematic diagram of the robot joint transmission structure.

Figure 4. Schematic diagram of the robot joint spindle.

Figure 5. Schematic diagram of robot joint control.

Figure 6. Schematic diagram of the CAN bus connection of the robot joint.

Figure 7. Schematic diagram of robot joint operation detection.

In the attached drawings: 1-output flange; 2-harmonic reducer; 3-frame oil seal fixing part; 4-main shell; 5-spindle bearing plate; 6-spindle bearing; 7-brake; 8-return shaft bearing Fixed parts; 9-drive controller; 10-spindle seal bearing; 11-wave generator; 12-skeleton oil seal; 13-permanent magnet synchronous motor; 14-joint spindle; 15-incremental encoder; 16-return shaft bearing; 17 - Absolute encoder; 18 - Sealed housing.

Detailed ways

The present invention will be further described below in conjunction with specific embodiments. The accompanying drawings are only used for exemplary description, are only schematic diagrams and are not real objects, and should not be construed as limitations of this patent. In order to better illustrate the present invention, the drawings are enlarged or reduced, and do not represent the actual size. Certain well-known structures and descriptions thereof may be omitted in the drawings.

The same parts in the present invention use the same reference numbers,

Example

1 to 4 are the first embodiment of the present invention, including a housing 4, an output flange 1 for connecting the load and the robot joint, the flange is provided with a return shaft, and the housing 4 has an integrated main shaft bearing Fixing part 5, the main shaft 14 has an integrated harmonic reducer wave generator structure, the rotor of the permanent magnet synchronous motor 13 is fixed on the main shaft 14, the rotor part of the customized power-loss brake 7, the incremental encoder 15, the absolute encoder The rotor part of 17; the main shaft 14 is respectively fixed on the output flange 1 and the housing 4 through the bearing 11 and the bearing 6; the fixed part 8 of the return shaft is fixed with the drive controller 9, the stator structure of the power-off brake 7 and the return The shaft bearing 16; the stator structure of the main shaft bearing 6 and the incremental encoder 15 is fixed on the integrated main shaft bearing fixing part; the sealing casing 18 is fixed at the rear end of the casing.

The housing 4 is fixed to the harmonic reducer 2 by 4 fixing bolts on the steel wheel, and the other 12 bolt holes on the harmonic reducer are used to fix the robot joints on the fixing parts of the robot. There is a skeleton oil seal 12 between the harmonic reducer 2 and the housing 4, and a sealed bearing 10 between the harmonic reducer 2 and the output flange 1. The skeleton oil seal 12 and the sealed bearing 10 are used to seal the harmonic reducer. , to prevent oil leakage.

The incremental encoder rotor is fixed on the main shaft 4 by gluing, and the incremental encoder stator is fixed on the main shaft bearing fixing member 5, so as to realize the purpose of common fixing member and reducing mechanical structure.

The rotor of the brake 7 is connected with the main shaft 4 through interference fit, and the stator is installed on the return shaft bearing fixing member 8, which can provide a braking torque of 5N·M during power failure braking.

The stator of the absolute encoder is installed on the outer side of the return shaft fixing member 8, the rotor of the absolute encoder is installed at the end of the return shaft, the output flange drives the load to rotate, and the angular acceleration is transmitted to the absolute encoder through the return shaft.

In order to ensure the tightness of the sealed housing 18 and the housing 4, a sealing gasket is used to increase the overall tightness during installation. The shell of the joint is made of aviation aluminum alloy, and the shell includes the fixing flange of the harmonic reducer, the motor compartment, the brake compartment and the sensor compartment. The rear end is made of 3D printing material to drive the control compartment.

This design has a hollow diameter of 7MM to meet the requirements of hollow wiring. The hollow wiring can increase the rotation range of the robot joint, enabling it to perform 360° continuous rotation.

The stator of the permanent magnet synchronous motor 13 is installed in the motor compartment of the casing, the rotor of the permanent magnet synchronous motor 13 is installed on the main shaft 14 , and the motor circuit is connected to the drive control board through the through hole on the integrated bearing fixture 5 .

The invention improves the connection mode of the harmonic reducer and the motor, reduces the sealing bearing between the harmonic reducer and the motor, and adopts a skeleton oil seal for sealing. The purpose of reducing the mechanical structure and increasing the degree of integration is achieved. The main shaft is fixed with a bearing at the rear end of the motor, which can better suppress the radial runout and increase the stability of the system.

The invention reduces the brake fixing frame, the incremental encoder fixing frame and the absolute encoder fixing frame, and the brake and the encoder are fixed on the bearing fixing parts by bolts or copper columns, which reduces the mechanical structure and increases the system stability.

Figure 4 shows the hollow main shaft. The main shaft is designed with an integrated wave generator structure. The stepped main shaft reserves the size allowance of each step. In actual assembly, the influence of precision on the actual robot joints is effectively reduced.

The joint adopts dual encoders to improve the positioning accuracy. The joint is controlled and positioned with high precision through the current loop, speed loop and position loop. The control process is shown in Figure 5. The joint motor detects the output current of each phase of the motor through the Hall device. Negative feedback performs PID adjustment for the current setting, so that the output current is as close as possible to the set current and controls the motor torque; the drive controller performs negative feedback PID adjustment by detecting the relative signal of the extreme encoder at the joint point. The inner PID output is directly the setting of the current loop; the position loop is the outermost loop, and the motor position is determined by detecting the position signal of the encoder at the end of the joint.

The invention adopts CAN bus communication, and can connect multiple robot joints through the bus. Built-in temperature sensor, vibration sensor, motor input encoder, and output encoder, which can conduct real-time bus monitoring of its speed, torque current, position, vibration information, and temperature information, and can also perform wireless communication through the built-in WIFI module. Operational status monitoring.

Claims (9)

1. A drive-control integrated collaborative robot joint with running state monitoring function is characterized in that: harmonic reducer, magnetic synchronous motor, harmonic reducer, motor end encoder, end encoder, temperature sensor, brake, The driver, the joint spindle, the end return shaft, the sealed bearing and the oil seal are all integrated in the casing; the speed information is transmitted to the encoder inside the casing through the end return shaft; the drive controller is integrated at the end of the joint. 2. The drive-control integrated collaborative robot joint with running state monitoring function according to claim 1, characterized in that: a single shell design method is adopted, the main bearing fixing part and the shell are integrated in structure, and harmonic deceleration is adopted. The generator is fixed on the shell through the flange; the permanent magnet synchronous motor is fixed in the shell motor compartment by gluing; the harmonic reducer wave generator and the motor spindle are designed as an integral structure, and the main bearing, the motor rotor and the brake are installed on the spindle. The rotor, the incremental encoder rotor, the skeleton oil-sealed rotor, the main shaft is fixed in the harmonic reducer and passes through the motor stator, and is fixed in the shell through the front and rear bearings; the return shaft is fixed on the harmonic reducer flex wheel, and through the The hollow main shaft is returned to the inside of the casing, and the absolute encoder rotor is installed on the returning main shaft; the encoder stator is installed on the casing. 3 . The drive-control integrated collaborative robot joint with running state monitoring function according to claim 1 or 2 , wherein the shell is made of aviation aluminum alloy. 4 . 4. A drive-control integrated collaborative robot joint with running state monitoring function according to claim 1 or 2, characterized in that: the power component comprises a permanent magnet synchronous motor and a harmonic reducer; the permanent magnet synchronous motor is harmonious The wave reducer is connected by an integrated main shaft, and the main shaft is a mechanical structure shared by the harmonic wave generator and the rotor of the permanent magnet synchronous motor; the harmonic reducer is directly connected to the shell by fixing the rigid wheel, and the stator of the permanent magnet synchronous motor is directly connected to the shell. It is fixed in the housing motor compartment by means of gluing, and the main shaft is fixed by two sealed bearings with the end connecting flange and the housing bearing flange. 5. A drive-control integrated collaborative robot joint with running state monitoring function according to claim 1 or 2, characterized in that: the main shaft and the main shaft of the harmonic reducer are designed in an integrated manner, the two ends of the main shaft are fixed by bearings, and the shell is fixed. The bearing mounting flange is installed in the body. 6. The drive-control integrated collaborative robot joint with a running state monitoring function according to claim 1, wherein the speed measuring assembly comprises two encoders, which are an absolute encoder at the end and an incremental encoder at the motor end. ;The incremental encoder at the motor end is directly fixed on the joint spindle, the end output encoder is fixed on the return shaft of the end output flange, one end of the return shaft is fixed on the end output flange through the flange, and the other end is fixed on the shell on the inner support bearing. 7. A drive-control integrated collaborative robot joint with running state monitoring function according to claim 1, characterized in that: the brake selects a flat large-diameter permanent magnet power-off brake, and the brake is fixed on the bearing flange; If power is lost during operation or a braking command is received, the principle of friction braking will be used to lock the main shaft for braking. 8. The drive-control-integrated collaborative robot joint with a running state monitoring function according to claim 1, wherein the drive controller selects a circular structure, the integrated driver and the controller are integrated, and the driver also has CAN Bus communication, serial communication, and WIFI wireless communication, with temperature sensors and vibration sensors; CAN communication has the characteristics of strong real-time data communication between nodes in the network, connecting multiple robot joints through CAN bus to communicate with the host computer, The joint transmits the rotational speed, current, position, temperature, and vibration information of the joint through the WIFI wireless module. 9 . The drive-control integrated collaborative robot joint according to claim 1 , wherein the 360° continuous rotation is realized through the hollow shaft. 10 .

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