A robot joint friction model calibration device and method

Abstract

The present application belongs to the technical field of six-degree-of-freedom vertical multi-joint industrial robot electromechanical coupling parameter calibration, and particularly relates to a robot joint friction model calibration device and method. The device comprises a base, a waist seat, a two-axis speed reducer, a large arm, a load, a detection assembly and a support, wherein the base is arranged on the support, the waist seat is connected with the base, the two-axis speed reducer is arranged on the waist seat, the input end of the two-axis speed reducer is connected with the detection assembly, one end of the large arm is connected with the output end of the two-axis speed reducer, the load is arranged on the other end of the large arm, the large arm is swung upward to a set angle through the detection assembly, the large arm is swung downward again under the gravity of the load, and the rotation angle and torque curve of the large arm are obtained through the detection assembly. The present application automatically collects torque and rotation speed curves online, effectively calibrates the friction and load mass relationship curve of the robot joint friction model, and provides mechanical physical data for the matching optimization of the robot electromechanical parameters of the robot.

Description

Technical Field

[0001] This invention belongs to the field of electromechanical coupling parameter calibration technology for six-degree-of-freedom vertical multi-joint industrial robots, and specifically relates to a robot joint friction model calibration device and method. Background Technology

[0002] The calibration of robot joint friction models is one of the key parameters in the calibration of robot electromechanical coupling parameters. The friction of joints in industrial machines varies under different load conditions, dynamic positions, and postures. Researching friction modeling techniques for industrial robot electromechanical coupling systems, constructing an electromechanical coupling system model that integrates the coupling behaviors of multiple parameters in a "machine-electric-control" system, and revealing the influence mechanisms and action principles among coupling factors are crucial. Overcoming the challenges of electromechanical coupling parameter calibration techniques is essential. This involves identifying the main factors and key parameters affecting the performance of the robot's electromechanical system, extracting the minimum identifiable variable set, optimizing the excitation trajectory, and studying electromechanical coupling parameter identification strategies to achieve optimal matching of robot electromechanical parameters. Therefore, a robot joint friction model calibration device and method are urgently needed. Summary of the Invention

[0003] To address the aforementioned problems, the present invention aims to provide a robot joint friction model calibration device and method to achieve the goal of matching and optimizing robot electromechanical parameters.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] This invention provides a robot joint friction model calibration device, including a base, a waist seat, a two-axis reducer, a large arm, a load, a detection component, and a support. The base is mounted on the support, the waist seat is connected to the base, the two-axis reducer is mounted on the waist seat, the input end of the two-axis reducer is connected to the detection component, one end of the large arm is connected to the output end of the two-axis reducer, and the load is mounted on the other end of the large arm. The detection component causes the large arm to swing upward to a set angle, and the large arm then swings downward under the gravity of the load. The detection component obtains the rotation angle and torque curve of the large arm.

[0006] In one possible implementation, the detection assembly includes a connecting bracket, a torque and speed sensor, a handwheel, and a drive shaft. The connecting bracket is connected to the support, the torque and speed sensor is mounted on the connecting bracket, one end of the drive shaft is connected to one end of the torque and speed sensor, and the other end of the drive shaft is connected to the input end of the two-axis reducer. The handwheel is mounted on the drive shaft. The torque and speed sensor is used to detect the torque and speed of the drive shaft.

[0007] In one possible implementation, the power input side of the two-axis reducer is provided with a two-axis motor interface, which is connected to an adapter plate. The drive shaft is rotatably connected to the adapter plate via bearings, and the input gear of the two-axis reducer is mounted on the drive shaft.

[0008] In one possible implementation, the other end of the torque-speed sensor is provided with an eddy current brake.

[0009] In one possible implementation, the load includes a wire rope, a mandrel, and multiple load discs, wherein the multiple load discs are mounted on the mandrel, and the upper end of the mandrel is connected to the other end of the boom via the wire rope.

[0010] In one possible implementation, the bracket has an L-shaped structure, with the axis of the base arranged horizontally, and the base and the waist support are relatively fixed.

[0011] Based on the above concept, another aspect of the present invention provides a calibration method using the robot joint friction model calibration device described above, comprising the following steps:

[0012] Step S1: Secure the robot, consisting of the base, waist support, two-axis reducer, and upper arm, to the support frame in place;

[0013] Step S2: Install the detection component;

[0014] Step S3: Attach the load to the end of the boom;

[0015] Step S4: Manually rotate the handwheel to rotate the upper arm to the swing angle θ;

[0016] Step S5: Release the rotating handwheel, and the boom will swing downward under the gravity of the load; the torque and speed sensor detects the torque and speed of the drive shaft, thereby obtaining the boom's rotation angle-torque curve information;

[0017] Step S6: Repeat steps S1 to S5 to obtain the rotation angle-torque curve information of N booms by varying the number of load plates.

[0018] Step S7: Input the N rotation angle-torque curve information into the robot's friction model, and then calibrate the theoretical and experimental values ​​of the robot's friction model.

[0019] The advantages and beneficial effects of this invention are as follows: This invention provides a robot joint friction model calibration device and method, which effectively calibrates the relationship curve between friction and load mass of the robot joint friction model, providing mechanical and physical data for the matching and optimization of robot electromechanical parameters; this invention conforms to ergonomics, is safe to operate, and the manual operation area is far away from moving parts; it has a high degree of automation, automatically collecting torque and speed curves online.

[0020] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings.

[0021] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0022] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0023] Figure 1 This is an isometric view of a robot joint friction model calibration device according to the present invention;

[0024] Figure 2 This is a side view of a robot joint friction model calibration device according to the present invention;

[0025] Figure 3 This is a schematic diagram of the detection component in this invention.

[0026] In the diagram: 1-base, 2-waist seat, 201-single-axis reducer, 202-single-axis motor, 203-two-axis motor interface, 3-two-axis reducer, 4-boom, 5-load, 501-wire rope, 502-spindle, 503-load plate, 6-detection component, 601-eddy current brake, 602-connecting bracket, 603-torque and speed sensor, 604-handwheel, 605-drive shaft, 606-bearing, 607-adapter plate, 608-two-axis reducer input gear, 609-coupling I, 6010-coupling II, 7-load center, 9-bracket, θ-swing angle. Detailed Implementation

[0027] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0028] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0029] One embodiment of the present invention provides a robot joint friction model calibration device, which effectively calibrates the relationship curve between friction and load mass of the robot joint friction model, providing mechanical and physical data for the matching and optimization of robot electromechanical parameters. See also Figures 1 to 3 As shown, the robot joint friction model calibration device includes a base 1, a waist seat 2, a two-axis reducer 3, a large arm 4, a load 5, a detection component 6, and a support 9. The base 1 is mounted on the support 9, the waist seat 2 is connected to the base 1, the two-axis reducer 3 is mounted on the waist seat 2, the input end of the two-axis reducer 3 is connected to the detection component 6, one end of the large arm 4 is connected to the output end of the two-axis reducer 3, and the load 5 is mounted on the other end of the large arm 4. The detection component 6 causes the large arm 4 to swing upward to a set angle, and the large arm 4 then swings downward under the gravity of the load 5. The detection component 6 obtains the rotation angle and torque curve of the large arm 4.

[0030] See Figure 1 , Figure 2 As shown, in this embodiment of the invention, the support 9 has an L-shaped structure, and its lower end is fixed to the ground. The axis of the base 1 is arranged horizontally, and the base 1 and the waist seat 2 are relatively fixed. Specifically, since the base 1 and the waist seat 2 are connected by a shaft reducer 201, the brake of the shaft motor 202 is activated, making the base 1 and the waist seat 2 relatively stationary.

[0031] See Figure 3 As shown, in an embodiment of the present invention, the detection component 6 includes a connecting bracket 602, a torque and speed sensor 603, a handwheel 604, and a drive shaft 605. The connecting bracket 602 is connected to the bracket 9. The torque and speed sensor 603 is disposed on the connecting bracket 602. One end of the drive shaft 605 is connected to one end of the torque and speed sensor 603, and the other end of the drive shaft 605 is connected to the input end of the two-axis reducer 3. The handwheel 604 is disposed on the drive shaft 605. The torque and speed sensor 603 is used to detect the torque and speed of the drive shaft 605.

[0032] Furthermore, the power input side of the two-axis reducer 3 is provided with a two-axis motor interface 203, which is connected to the adapter plate 607. The drive shaft 605 is rotatably connected to the adapter plate 607 via a bearing 606. The two-axis reducer input gear 608 of the two-axis reducer 3 is mounted on the drive shaft 605. The detection component 6 is mechanically coupled to the planetary gear 301 of the two-axis reducer 3.

[0033] Furthermore, one end of the torque and speed sensor 603 is connected to the drive shaft 605 via coupling II 6010, and the other end of the torque and speed sensor 603 is connected to the eddy current brake 601 via coupling I 609. The eddy current brake 601 is used to brake the drive shaft 605.

[0034] See Figure 1 As shown, in an embodiment of the present invention, the load 5 includes a wire rope 501, a spindle 502 and a plurality of load discs 503, wherein the plurality of load discs 503 are mounted on the spindle 502, and the upper end of the spindle 502 is connected to the other end of the boom 4 via the wire rope 501.

[0035] The present invention provides a robot joint friction model calibration device with a high degree of automation. It automatically collects torque and speed curves online, effectively calibrates the relationship curve between friction and load mass of the robot joint friction model, and provides mechanical and physical data for matching and optimizing the robot's electromechanical parameters.

[0036] Another embodiment of the present invention provides a method for calibrating a robot joint friction model, which is implemented using the robot joint friction model calibration device described in the above embodiment. See also Figures 1 to 3 As shown, the calibration method includes the following steps:

[0037] Step S1: Secure the robot, consisting of base 1, waist support 2, two-axis reducer 3, and upper arm 4, to the support 9 in place;

[0038] Step S2: Install detection component 6;

[0039] Step S3: Attach the load 5 to the end of the boom 4;

[0040] Step S4: Manually rotate handwheel 604 to rotate the upper arm 4 to the swing angle θ;

[0041] Step S5: Release the rotating handwheel 604, and the boom 4 will swing downward under the gravity drive of the load 5; the torque and speed sensor 603 detects the torque and speed of the drive shaft 605, thereby obtaining the rotation angle-torque curve information of the boom 4.

[0042] Step S6: Repeat steps S1 to S5 to obtain the rotation angle-torque curve information of N booms 4 by varying the number of load plates 503.

[0043] Step S7: Input the N rotation angle-torque curve information into the robot's friction model, and then calibrate the theoretical and experimental values ​​of the robot's friction model.

[0044] Specifically, the swing angle θ is the angle between the boom 4 and the horizontal plane. The weight of the load 5 is k×m+a; where k is the number of load discs 503, m is the weight of the load discs 503, and a is the sum of the weights of the wire rope and the spindle 502. Therefore, the torque relationship between the load 5 and the two-shaft reducer 3 is as follows:

[0045] T=(k×m+a)×L×cosθ

[0046] Where T is the torque and L is the boom length.

[0047] The load 5 mounted at the end of the boom 4 can achieve different loading weights through different numbers of load discs 503, and different numbers of load discs 503 share a common load center 7. Preferably, the two-axis reducer 3 adopts an RV700H-B type reducer, which belongs to the RV type reducer. The eddy current brake 601 adopts the WZ-10 specification manufactured by China Aerospace Electromechanical Automatic Control Co., Ltd. The housing of the eddy current brake 601 is fixedly connected to the bracket 9 through the connecting bracket 602. The rotor of the eddy current brake 601 is connected to the rotor of the torque and speed sensor 603 through the coupling I 609. The torque and speed sensor 603 is selected from Beijing Zhonghang Kedian Measurement and Control Technology Co., Ltd., with the specification model ZHO07-FT-3. It has an accuracy class of 0.2, a torque range of 3Nm, a speed range of 4000RPM, 30 teeth, and a tooth power supply of 12V. The housing of the torque and speed sensor 603 is fixedly connected to the bracket 9 through the connecting bracket 602. One end of the drive shaft 605, simulating the input shaft of a motor, is locked to the input gear 608 of the two-axis reducer via screws and keys. The other end of the drive shaft 605 is connected to the rotor of the torque and speed sensor 603 via coupling II 6010. The middle part of the drive shaft 605 is connected to the two-axis motor interface 203 via bearing 606, adapter plate 607, and screws, forming a rotary kinematic pair. The bearing 606 is preferably an industrial robot cross roller bearing, and more preferably the NSK brand RU85UUCC0P5.

[0048] This invention provides a method for calibrating a robot joint friction model, which effectively calibrates the relationship curve between friction and load mass of the robot joint friction model, providing mechanical and physical data for matching and optimizing the robot's electromechanical parameters; this invention conforms to ergonomics, is safe to operate, and the manual operation area is far away from moving parts; it has a high degree of automation, automatically collecting torque and speed curves online.

[0049] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A calibration device for a robot joint friction model, characterized in that, The device includes a base (1), a waist seat (2), a two-axis reducer (3), a boom (4), a load (5), a detection component (6), and a bracket (9). The base (1) is mounted on the bracket (9), the waist seat (2) is connected to the base (1), the two-axis reducer (3) is mounted on the waist seat (2), the input end of the two-axis reducer (3) is connected to the detection component (6), one end of the boom (4) is connected to the output end of the two-axis reducer (3), and the load (5) is mounted on the other end of the boom (4). The boom (4) is swung upward to a set angle by the detection component (6), and then swung downward under the gravity of the load (5). The rotation angle and torque curve of the boom (4) are obtained by the detection component (6). The detection component (6) includes a connecting bracket (602), a torque and speed sensor (603), a handwheel (604), and a drive shaft (605). The connecting bracket (602) is connected to the bracket (9). The torque and speed sensor (603) is mounted on the connecting bracket (602). One end of the drive shaft (605) is connected to one end of the torque and speed sensor (603), and the other end of the drive shaft (605) is connected to the input end of the two-axis reducer (3). The handwheel (604) is mounted on the drive shaft (605). The torque and speed sensor (603) is used to detect the torque and speed of the drive shaft (605). The load (5) includes a wire rope (501), a spindle (502) and multiple load discs (503), wherein the multiple load discs (503) are mounted on the spindle (502), and the upper end of the spindle (502) is connected to the other end of the boom (4) via the wire rope (501).

2. The robot joint friction model calibration device according to claim 1, characterized in that, The power input side of the two-axis reducer (3) is provided with a two-axis motor interface (203), which is connected to the adapter plate (607). The transmission shaft (605) is rotatably connected to the adapter plate (607) through a bearing (606). The two-axis reducer input gear (608) of the two-axis reducer (3) is set on the transmission shaft (605).

3. The robot joint friction model calibration device according to claim 1, characterized in that, The other end of the torque and speed sensor (603) is provided with an eddy current brake (601).

4. The robot joint friction model calibration device according to claim 1, characterized in that, The bracket (9) has an L-shaped structure, the axis of the base (1) is arranged in the horizontal direction, and the base (1) and the waist seat (2) are relatively fixed.

5. A calibration method using the robot joint friction model calibration device according to claim 1, characterized in that, Includes the following steps: Step S1: Fix the robot, consisting of the base (1), waist seat (2), two-axis reducer (3) and upper arm (4), and the support (9) into place; Step S2: Install the detection component (6); Step S3: Attach the load (5) to the end of the boom (4); Step S4: Manually rotate the handwheel (604) to rotate the upper arm (4) to the swing angle θ; Step S5: Release the rotating handwheel (604), and the boom (4) will swing downward under the gravity drive of the load (5); the torque and speed sensor (603) detects the torque and speed of the drive shaft (605) to obtain the rotation angle-torque curve information of the boom (4); Step S6: Repeat steps S1 to S5, and obtain the rotation angle-torque curve information of N booms (4) by varying the number of load plates (503); Step S7: Input the N rotation angle-torque curve information into the robot's friction model, and then calibrate the theoretical and experimental values ​​of the robot's friction model.

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