CN104128928A - Robot joint module and control method thereof - Google Patents

Abstract

The present invention discloses a robot joint module and a control method thereof, wherein a passive component is stacked on a deceleration mechanism, a plurality of buffer springs are stacked on the passive component, and a sensor is stacked on the buffer spring to form a multi-stacked joint module. The phase difference angle of the torsion buffer spring is detected to control the motor to rotate in the direction of the resistance force to ensure operation safety.

Description

Robot joint module and control method thereof

technical field

The invention relates to a robot, in particular to a joint module in the robot that provides elastic actuation force for driving a load, and a method for controlling the rotation of the joint module.

Background technique

The robot has the flexibility of movement and the accuracy of positioning, and also has the characteristics of continuous operation. In the environment of high labor costs and continuous labor disputes, it has gradually developed into a powerful tool for manufacturing and assembling products on the production line. The best weapon to reduce costs.

As shown in FIG. 1 , it is a side sectional view of a joint module of a robot in the prior art. The joint module 1 of the prior art robot is mainly composed of a motor (Motor) 2, an encoder (Encoder) 3, a reducer (Reducer) 4 and a transmission mechanism (transmission) 5, etc. which are connected in series on the same rotating shaft 6. The motor 2 provides power to rotate the rotating shaft 6 , and the encoder 3 located at the rear side of the motor 2 records the rotation angle of the rotating shaft 6 by detecting the rotation of the motor 2 . The reducer 4 utilizes planetary gear (Planetary gear) or harmonic gear (Harmonic gear) and other reduction mechanisms to reduce the speed of the motor 2 to drive the rotating shaft 6, to rotate the transmission mechanism 5 with a lower output speed, and then the transmission mechanism 5 provides the robot proper The moving speed drives the load. By detecting the rotation angle of the rotating shaft 6 recorded by the encoder 3, the moving position of the robot can be precisely controlled.

The robot in the prior art uses the output power of the joint module 1 to drive the object to a predetermined position. If it encounters an object with a large load or an operator and is blocked and cannot continue to rotate, although it can be detected by a sensor (not shown) Emergency braking due to obstacles, to stop the rotation of the joint module 1, to avoid damage to items or injury to operators.

However, the motor 2, the encoder 3, the reducer 4, and the transmission mechanism 5 of the joint module 1 are sequentially combined in series on the shaft 6 to form a bulky and heavy joint module 1, which is not only bulky and not conducive to the movement of the robot. Flexibility, and occupy too much space in the production line, and heavy weight will form a relatively strong movement inertia, which is not conducive to the mobile positioning of industrial robots. In addition, the joint module 1 rigidly drives larger objects. If the inertia continues to move, the joint module 1 of the stopped robot will face the danger of being crushed and damaged, and the operator who is crushed cannot push away from the stopped joint. Module 1 out of danger. Therefore, there are still problems to be solved urgently in terms of structure and control of the joint module of the robot.

Contents of the invention

The object of the present invention is to provide a joint module of a robot. Through multiple nested joint modules, the volume and weight of the joint module can be reduced, so as to increase the flexibility of movement of the robot.

In order to achieve the purpose of the aforementioned invention, the joint module of the robot of the present invention fixes the rotating shaft of the motor in the hollow interior of the casing, and the rotation angle of the rotating shaft is detected by the encoder, and the rotating speed reducer changes the output speed of the rotating shaft to rotate the passive part. Stacked on the outer periphery of the deceleration mechanism, one end of multiple buffer springs is fixed on the passive part, nested on the outer periphery of the passive part, the transmission flange is provided with a plurality of through holes, some of the through holes are connected to one end of the buffer spring as it rotates, and some The through hole of the load is connected to the load, and the sensor is sleeved on the outer circumference of the buffer spring and fixed on the casing to detect the rotation angle of the transmission flange.

Another object of the present invention is to provide a joint module of a robot, which uses a plurality of buffer springs arranged at cross intervals to form a single layer, and uses the number of buffer springs to adjust the buffer force of the preset joint module subjected to external resistance to provide a safe buffer space.

In order to achieve the purpose of the aforementioned invention, the joint module of the robot of the present invention is provided with a plurality of buffer springs intersecting at intervals to form a single-layer coiled tubular spring, and by selecting the number of buffer springs, the buffer force of the preset joint module subjected to external resistance is adjusted.

Another object of the present invention is to provide a control method for the joint module of the robot, which uses the buffer spring of the joint module to control the rotation of the joint module of the robot according to the compliance resistance, so as to avoid damage to the joint module and the operator, so as to ensure the safety of work.

In order to achieve the purpose of the aforementioned invention, the control method of the joint module of the robot in the first embodiment of the present invention, first detects the rotation angle of the motor; converts the rotation angle of the motor to the rotation angle of the passive part; detects the rotation angle of the transmission flange ;Calculate the angle difference between the rotation angle of the transmission flange and the rotation angle of the driven part; check that the angle difference is not greater than the buffer angle, then continue to detect, check that the angle difference is greater than the buffer angle, then control the motor so that the motor follows the direction of the resistance force, that is, the phase difference The direction generated by the angle turns to the preset safe angle, and then stops the motor from turning.

In order to achieve the purpose of the aforementioned invention, the control method of the joint module of the robot in the second embodiment of the present invention includes detecting the rotation angle of the motor; detecting the rotation angle of the transmission flange; calculating the rotation angle of the transmission flange and the rotation of the motor The difference angle of the angle; check that the difference angle is not greater than the buffer angle, then continue to detect, check that the difference angle is greater than the buffer angle, then control the motor to rotate to the preset safe angle in the direction generated by the difference angle; then stop the motor rotation.

Description of drawings

Fig. 1 is the side sectional view of the joint module of prior art robot;

Fig. 2 is the perspective view of the joint module of robot of the present invention;

Fig. 3 is an exploded view of parts of the joint module of the robot of the present invention;

Fig. 4 is a side sectional view of the joint module of the robot of the present invention;

Fig. 5 is a schematic diagram of joint module buffering of the robot of the present invention;

6 is a flow chart of the joint module control method of the robot according to the first embodiment of the present invention;

FIG. 7 is a flowchart of a method for controlling a joint module of a robot according to a second embodiment of the present invention.

Symbol Description

10 joint modules

11 shell

12 fixed end

13 outputs

14 motor

15 encoders

16 reducer

17 transmission mechanism

18 cables

19 shafts

20 deceleration mechanism

21 Passive parts

22 buffer spring

23 sensors

24 transmission flange

25 bearing cover

26 through holes

27 bearings

28 bolts

Detailed ways

In order to achieve the above object, the present invention adopts the technical means and its effects, hereby give preferred embodiments, and illustrate as follows in conjunction with the accompanying drawings.

Please refer to Fig. 2, Fig. 3 and Fig. 4 at the same time, Fig. 2 is a perspective view of the joint module of the robot of the present invention, Fig. 3 is an exploded view of parts of the joint module of the robot of the present invention, and Fig. 4 is a side section of the joint module of the robot of the present invention picture. The joint module 10 of the robot of the present invention has a hollow shell 11 , one end of the shell 11 is a fixed end 12 , and the other end is an output end 13 . The hollow interior of the casing 11 accommodates a motor 14 , an encoder 15 , a speed reducer 16 , a transmission mechanism 17 and the like. The motor 14 is fixed on the fixed end 12 of the casing 11 , and is connected to external electric power through the cable 18 to provide power to rotate the rotating shaft 19 . The encoder 15 arranged at the rear side of the motor 14 records the rotation angle of the rotating shaft 19 by detecting the rotation of the motor 14 . The speed reducer 16 is fixed inside the casing 11 and connected to the rotating shaft 19 on the front side of the motor 14, and the speed reducer 16 is driven to rotate by the rotating shaft 19. The speed reducer 16 uses a reduction mechanism 20 such as a planetary gear or a harmonic gear to change the rotational speed output by the rotating shaft 19 to rotate the driven member 21 at a lower rotational speed. The driven part 21 is in the shape of a cylindrical cap, nested on the outer periphery of the cylindrical reduction mechanism 20, and drives the connected transmission mechanism 17 to rotate.

The transmission mechanism 17 of the joint module 10 includes a buffer spring 22 , a sensor 23 , a transmission flange 24 , a bearing cover 25 and the like. The buffer spring 22 is a coiled tubular spring nestled on the outer periphery of the cylindrical cap-shaped passive part 21 . One end of the buffer spring 22 is fixed on the passive element 21 to rotate with the passive element 21 , and the other end is connected to the transmission flange 24 . The transmission mechanism 17 includes a plurality of buffer springs 22 , and the buffer force of the joint module 10 subjected to external resistance is adjusted by using the number of the buffer springs 22 . Each buffer spring 22 is arranged at intervals to form a single coiled tubular spring, which is sheathed on the outer periphery of the passive part 21 in a single layer, so as to reduce the nested volume. The sensor 23 is in the shape of a ring, and the inner ring is nested on the outer periphery of the buffer spring 22, and is adjacent to the end of the buffer spring 22 close to the transmission flange 24, and the outer ring of the sensor 23 is fixed on the inner surface of the housing 11 , used to detect the rotation angle of the transmission flange 24.

The transmission flange 24 is a disc shape, and the disc surface is provided with a plurality of through holes 26, and part of the through holes 24 is connected to one end of the buffer spring 22, so that the transmission flange 24 rotates with the buffer spring 22, and part of the through holes 26 can be Connect the output load (not shown) to rotate the load. A bearing 27 is arranged around the periphery of the transmission flange 24, and a bolt 28 is used to pass through the bearing cover 25, the bearing cover 25 is locked on the output end 13 of the casing 11, and the bearing 27 is fixed on the casing 11 to support the rotation of the transmission flange 24.

Please refer to FIG. 4 again. When the joint module 10 of the robot of the present invention is activated, the electric cable 18 is supplied with power from the external motor 14 to rotate the rotating shaft 19 . The rotation angle of the rotating shaft 19 is detected and recorded by the encoder 15 arranged at the rear side of the motor 14 . The speed reducer 16 fixed on the casing 11 is rotated by the rotating shaft 19 . The speed reducer 16 utilizes the reduction mechanism 20 to reduce the rotational speed output by the rotating shaft 19 to rotate the passive member 21 . The cylindrical cap-shaped passive part 21 is nested on the outer periphery of the cylindrical reduction mechanism 20, and one end of a plurality of coil-shaped buffer springs 22 is fixed on the passive part 21, and the intersecting intervals are arranged to form a single coil-tubular spring, and the single layer is nested again. The outer periphery of the passive element 21 rotates with the passive element 21, and the other end of the buffer spring 22 drives the transmission flange 24 to rotate to rotate the load. The sensor 23 for detecting the rotation angle of the transmission flange 24 is nested on the outer periphery of the buffer spring 22 .

Therefore, the joint module of the robot of the present invention can simplify the structure of the joint module and reduce The volume and weight of the joint module can further reduce the inertia of the joint module, so as to achieve the purpose of increasing the mobility of the robot. And by selecting the number of buffer springs, the buffer force of the preset joint module subjected to external resistance can be adjusted to achieve an appropriate safe buffer space.

Please refer to FIG. 4 and FIG. 5 at the same time. FIG. 5 is a schematic diagram of the joint module cushioning of the robot of the present invention. The joint module 10 of the robot of the present invention is rotated by the motor 14 to the rotating shaft 19, and the output speed of the rotating shaft 19 is reduced by the reducer 16 to rotate the passive member 21. The gear ratio can be designed to obtain a fixed deceleration ratio from the motor 14 to the passive member 21. Therefore, the encoder 15 detects and records the rotation angle of the rotating shaft 19 of the motor 14 , and can be converted into the rotation angle of the driven part 21 through calculation by a fixed deceleration ratio. The passive part 21 rotates the transmission flange 24 by the buffer spring 22. When the rotation load of the transmission flange 24 is not hindered, the transmission flange 24 rotates with the passive part 21, and the rotation angle of the transmission flange 24 detected by the sensor 23 It is synchronized with the rotation angle of the passive member 21 detected by the encoder 15, and the rotation angles of the two are consistent.

Once the rotating load of the transmission flange 24 is hindered, or pushed and moved by pressure when stationary, the transmission flange 24 and the passive part 21 connected to the two ends of the buffer spring 22 will force the buffer spring 22 to twist, allowing the sensor 23 to detect the transmission. The rotation angle F of the flange 24 is different from the rotation angle M of the driven part 21 detected by the encoder 15 by an angle θ. If the obstacle or pressure is not eliminated, the difference angle θ between the rotation angle of the transmission flange 24 detected by the sensor 23 and the rotation angle of the passive part 21 detected by the encoder 15 will become larger and larger, forcing the buffer spring 22 to increase The large torsion provides a buffer space for the joint module 10 of the robot to remove obstacles, so as to prevent the robot or obstacles from being damaged by the continuous rotational power of the joint module 10 .

However, the buffer spring 22 also has a limited amount of torsion, which cannot provide an excessive amount of buffer space. If the obstacle or pressure is not removed in time, the robot or obstacle will still be damaged in the end. Therefore, the joint module 10 of the present invention sets a limitation L on the buffer space, and presets the buffer angle β. When the rotating load of the driving flange 24 is blocked or squeezed when the load is stationary, the difference angle θ between the rotating angle of the driving flange 24 detected by the sensor 23 and the rotating angle of the passive member 21 detected by the encoder 15 is greater than the buffer angle β , the joint module 10 will comply with the resistance of the obstacle to prevent the rotation of the transmission flange 24, that is, the direction generated by the difference angle θ, control the motor 14 to rotate in the direction of the resistance, rotate the passive part 21 to the preset safe angle Δα, and then stop The motor rotates to avoid damage to the joint module, and at the same time, squeezed objects or operators are automatically out of danger to ensure safe operation.

As shown in FIG. 6 , it is a flow chart of the method for controlling the joint module of the robot according to the first embodiment of the present invention. The steps for controlling the joint module of the robot in the present invention are described in detail as follows: first step S1, detect the rotation angle of the motor; step S2, convert the rotation angle of the motor to the rotation angle of the passive part; step S3 detect the rotation of the transmission flange Angle; step S4, calculate the difference angle θ between the rotation angle of the transmission flange and the rotation angle of the passive part; step S5, check whether the difference angle θ is greater than the preset buffer angle β? If the difference angle θ is not greater than the buffer angle β, return to Step S1 continues to detect, if the difference angle θ is greater than the preset buffer angle β, then go to step S6, control the motor to follow the direction of the resistance force, that is, rotate in the direction generated by the difference angle θ, and rotate to the preset safe angle α; and then go to Step S7, stop the rotation of the motor.

As shown in FIG. 7 , it is a flow chart of the joint module control method of the robot according to the second embodiment of the present invention. In the previous embodiment, the transmission flange and the passive part at both ends of the buffer spring in the joint module are used as the calculation basis for the phase difference angle Δθ. But the motor rotates the driven part by reducing the speed of the rotating shaft through the reducer, and the fixed deceleration ratio from the motor to the driven part has a corresponding rotation angle. Therefore, the rotation angle of the motor can be detected and recorded by the encoder instead of the rotation angle of the driven element, so as to simplify the step S2 of the aforementioned conversion. The steps of controlling the joint module of the robot in the second embodiment of the present invention are described in detail as follows: first step T1, detect the rotation angle of the motor; step T2, detect the rotation angle of the transmission flange; step T3, calculate the rotation angle of the transmission flange The difference between the rotation angle and the rotation angle of the motor; step T4, check whether the difference angle is greater than the buffer angle β? If the difference angle is not greater than the buffer angle β, return to step T1 to continue detection, if the difference angle is greater than the buffer angle β, then to Step T5, control the motor to rotate in the direction of the resistance force, that is, rotate to the preset safe angle α in the direction generated by the difference angle; then go to step T6, stop the motor from rotating.

Therefore, the control method of the joint module of the robot of the present invention can use the buffer spring of the joint module to provide a buffer space for encountering obstacles, and when the buffer angle is exceeded, the motor is controlled to rotate at a safe angle in accordance with the resistance to avoid damage to the joint module , and allow items or operators to escape from danger automatically to achieve the purpose of ensuring operation safety.

The above are only preferred embodiments for conveniently illustrating the present invention, and the scope of the present invention is not limited to these preferred embodiments. Any changes made according to the present invention will not depart from the spirit of the present invention. , all belong to the scope of the patent application of the present invention.

Claims (9)

1. A joint module of a robot has a shell, and the hollow interior of the shell contains: A motor, fixed to the housing, provides power to rotate the shaft; an encoder for detecting the rotation angle of the rotating shaft; The reducer is rotated by the rotating shaft, and uses the reduction mechanism to change the output speed of the rotating shaft to rotate the passive part, and the passive part is nested on the outer periphery of the reduction mechanism; A plurality of buffer springs, one end of which is fixed to the passive part and is nested on the outer periphery of the passive part as it rotates; The transmission flange is provided with a plurality of through holes, some of which are connected to one end of the buffer spring as it rotates, and some of the through holes are connected to the load; and The sensor is in the shape of a ring, the inner ring is nested on the outer periphery of the buffer spring, and the outer ring is fixed on the inner surface of the shell to detect the rotation angle of the transmission flange. 2 . The joint module of the robot according to claim 1 , wherein the driven part is in the shape of a cylindrical cap, nested on the outer periphery of the cylindrical reduction mechanism. 3 . 3 . The joint module of the robot according to claim 1 , wherein the plurality of buffer springs are intersected and spaced to form a single layer of coiled tubular springs. 4 . 4. The joint module of the robot as claimed in claim 1, wherein the transmission flange is in the shape of a disc, and the plurality of through holes are provided on the disc. 5 . The joint module of the robot as claimed in claim 1 , wherein the buffer spring adjusts the buffer force of the preset joint module subjected to external resistance by a selected amount. 6 . 6. A control method for a joint module of a robot, the passive part and the transmission flange of the joint module are respectively connected to the two ends of the buffer spring, and the motor rotates the passive part through the reducer, and the steps of the control method include: (1) The rotation angle of the detected motor; (2) Convert the rotation angle of the motor to the rotation angle of the passive part; (3) Detect the rotation angle of the transmission flange; (4) Calculate the angle difference between the rotation angle of the transmission flange and the rotation angle of the passive part; (5) Check whether the phase difference angle is greater than the buffer angle, if the phase difference angle is not greater than the buffer angle, return to step (1) to continue detection, if the phase difference angle is greater than the buffer angle, then go to step (6); (6) Control the motor to rotate to the preset safe angle in the direction generated by the difference angle; (7) Stop the motor from rotating. 7. The control method of the joint module of the robot as claimed in claim 6, wherein the rotational angle of the motor is converted into the rotational angle of the passive element by reducing the rotational speed of the motor through the reducer to rotate the passive element with a fixed deceleration ratio. 8 . The control method of the joint module of the robot as claimed in claim 6 , wherein the direction generated by the phase difference angle is the direction in which the motor complies with the resistance force. 9. A method for controlling a joint module of a robot, the motor of the joint module drives the buffer spring to rotate the transmission flange through a reducer, and the steps of the control method include: (1) The rotation angle of the detected motor; (2) Detect the rotation angle of the transmission flange; (3) Calculate the angle difference between the rotation angle of the transmission flange and the rotation angle of the motor; (4) Check whether the phase difference angle is greater than the buffer angle, if the phase difference angle is not greater than the buffer angle, go back to step (1) to continue detection, if the phase difference angle is greater than the buffer angle, then go to step (5); (5) Control the motor to rotate to a preset safe angle in the direction generated by the angle difference; (6) Stop the motor from rotating.