Large-load robot transmission rigidity calibration device and method

Abstract

The invention belongs to the technical field of industrial robot body rigidity testing, and particularly relates to a large-load robot transmission rigidity calibration device and method. The device comprises a switching frame, a fixed cross beam, a test torque cross beam, a counterweight mechanism, a measuring instrument, a locking mechanism and a position changing machine, the switching frame is connected with a position changing rotating disc of the position changing machine, a to-be-calibrated robot joint is installed on the switching frame, and an output shaft of the to-be-calibrated robot joint and the position changing rotating disc are coaxial. An input shaft of the to-be-calibrated robot joint is locked through a locking mechanism; the test torque cross beam is connected with an output shaft of a to-be-calibrated robot joint, and counterweight mechanisms are arranged at two ends of the test torque cross beam; the fixed beam is connected to an output end shell of a to-be-calibrated robot joint, the measuring instrument is arranged at one end of the fixed beam, one end of the test torque beam is loaded, the torsion angle of the other end of the test torque beam is measured through the measuring instrument, and therefore rigidity calibration of the robot joint is achieved. The rigidity testing device is simple in structure, capable of effectively controlling rigidity testing errors, accurate in testing result and low in cost.

Description

Technical Field

[0001] The invention belongs to the technical field of industrial robot body stiffness testing, and in particular relates to a heavy-load robot transmission stiffness calibration device and method. Background Art

[0002] Industrial robots are multi-joint manipulators or multi-degree-of-freedom machine devices widely used in the industrial field. They have a certain degree of automation and can rely on their own power and control capabilities to achieve various industrial processing and manufacturing functions. Industrial robots are widely used in various industrial fields such as electronics, logistics, and chemicals. With the continuous development of robot technology and the increasing popularity of intelligent manufacturing, traditional large-load industrial robots have become the focus of the manufacturing industry. Among them, large-load industrial robots have been introduced into production and manufacturing by more and more manufacturers due to their safety, ease of use, flexibility, low investment, and rapid production.

[0003] The transmission stiffness of a robot refers to the ability of the robot's structural transmission chain to resist deformation under the action of acceleration torque. It is an important performance indicator of an industrial robot. It not only determines the positioning accuracy of the industrial robot under load, but also affects the dynamic characteristics of the robot's body structure, the robot's vibration suppression strategy, and the basic data for optimizing the robot's beat capability. Joints are an important part of collaborative robots, and the stiffness index of joints also greatly affects the dynamic and static performance of the entire large-load robot. Therefore, the evaluation of the joint stiffness index of collaborative robots is particularly important. At present, when testing joint stiffness, it is usually necessary to build a relatively precise tooling, and measure it separately after the joints are assembled. This method is relatively complicated to operate and has a high testing cost. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to provide a large-load robot transmission stiffness calibration device and method to solve the problem that the existing joint stiffness test requires the construction of relatively precise tooling, and the measurement is performed separately after the joints are assembled, which is complicated to operate and has high testing costs.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] On the one hand, the present invention provides a large-load robot transmission stiffness calibration device, including an adapter frame, a fixed beam, a test torque beam, a counterweight mechanism, a measuring instrument, a locking mechanism and a positioner, wherein the adapter frame is connected to the positioner rotating disk of the positioner, the robot joint to be calibrated is installed on the adapter frame, and the output shaft of the robot joint to be calibrated is coaxial with the positioner rotating disk, and the input shaft of the robot joint to be calibrated is locked by the locking mechanism; the middle part of the test torque beam is connected to the output shaft of the robot joint to be calibrated, and the two ends of the test torque beam are respectively connected to two groups of counterweight mechanisms; the fixed beam is connected to the output end housing of the robot joint to be calibrated, the measuring instrument is arranged at one end of the fixed beam, and the end of the test torque beam away from the measuring instrument is loaded, and the torsion angle of the test torque beam is measured by the measuring instrument, thereby realizing the stiffness calibration of the robot joint.

[0007] The counterweight mechanism comprises a configuration cylinder, the counterweight cylinder is suspended at the end of the test torque beam, and a counterweight medium of a fixed mass is added into the counterweight cylinder.

[0008] The upper parts of both ends of the test torque beam are provided with test rods, and the test rods are used to cover load plates of a certain mass, and loading of different masses can be achieved through different numbers of load plates.

[0009] The measuring instrument includes a magnetic base, a dial indicator bracket and a dial indicator, wherein one end of the dial indicator bracket is fixedly connected to the magnetic base, and the other end is equipped with a dial indicator; the magnetic base is magnetically attracted to the fixed beam, the dial indicator is located above the test torque beam, and the needle of the dial indicator is in contact with the test torque beam.

[0010] The locking mechanism includes a locking disk and a locking shaft, wherein the locking disk is symmetrically provided with two arc-shaped waist holes, the locking shaft is fixed at the center of the locking disk, the locking shaft is connected to the input shaft of the robot joint to be calibrated through a key, and the locking disk is connected to the input end housing of the robot joint to be calibrated through two manual turning screws respectively accommodated in the two arc-shaped waist holes.

[0011] The robot joint to be calibrated is the forearm of a six-degree-of-freedom vertical multi-joint industrial robot.

[0012] Another aspect of the present invention provides a calibration method using the large-load robot transmission stiffness calibration device as described above, the calibration method comprising the following steps:

[0013] Step S1: Install the robot joint to be calibrated on the positioner;

[0014] First, install the adapter frame on the positioner's positioner rotating disk, then connect the input end housing of the robot joint to be calibrated to the adapter frame, and make the axis of the output shaft of the robot joint to be calibrated collinear with the axis of the positioner rotating disk;

[0015] Step S2: the positioner adjusts the angle of the positioner rotating disk to align the transfer frame and level it with a level ruler;

[0016] Step S3: the middle of the test torque beam is connected to the output shaft of the robot joint to be calibrated, the counterweight mechanism is connected to both ends of the test torque beam, and the test torque beam is leveled with a level ruler, and then the input shaft of the robot joint to be calibrated is locked by a locking mechanism;

[0017] Step S4: Connect the fixed beam to the output end housing of the robot joint to be calibrated, and install the measuring instrument on the fixed beam;

[0018] Step S5: loading a load step by step at one end of the test torque beam, and measuring the torsion angle step by step at the other end of the test torque beam by using a measuring instrument; then removing the load step by step, and measuring the change of the torsion angle step by step;

[0019] Loads are applied step by step at the other end of the test torque beam, and the reverse torsion angle is measured step by step by a measuring instrument; then the loads are removed step by step, and the reverse torsion angle change is measured step by step, so as to obtain the first stiffness hysteresis closed-loop curve of the first phase of the transmission gear meshing of the robot joint to be calibrated;

[0020] Step S6: the positioner adjusts the positioner rotating disk to step the preset angle, unlocks the locking mechanism, rotates the input shaft of the robot joint to be calibrated, keeps the test torque beam in a horizontal state, and levels it with a level ruler;

[0021] Step S7: executing step S5 to obtain a second stiffness hysteresis curve of the second phase of the transmission gear meshing of the robot joint to be calibrated;

[0022] Step S8: Repeat steps S6 and S7 to obtain multiple transmission stiffness hysteresis curves, and perform data processing and analysis.

[0023] The advantages and beneficial effects of the present invention are: a large-load robot transmission stiffness calibration device provided by the present invention has a simple structure and can utilize existing robot joints and joint arms to test joint stiffness without the need for additional tooling. On the one hand, it can effectively control errors and make the test results more accurate; on the other hand, it utilizes existing positioners, requires less investment, and is more cost-effective.

[0024] The method of the present invention is simple to operate, can effectively and quickly test the stiffness of the robot joints, and has high testing accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is an axonometric diagram of a vertical multi-jointed robot;

[0026] Figure 2This is an axonometric diagram of a transmission stiffness calibration device for a large-load robot according to the present invention;

[0027] Figure 3 for Figure 2 A partial enlarged view of the middle part;

[0028] Figure 4 It is a front view of a transmission stiffness calibration device for a large-load robot according to the present invention;

[0029] Figure 5 for Figure 4 A partial enlarged view of point C in the middle;

[0030] Figure 6 for Figure 4 Partial cross-sectional view of middle BB;

[0031] Figure 7 Schematic diagram of the non-positive position calibration of the robot forearm in an embodiment of the present invention;

[0032] Figure 8 Schematic diagram of different transmission gear meshing phases in an embodiment of the present invention.

[0033] In the figure: 1-six degrees of freedom vertical multi-joint industrial robot, 101-base, 102-waist seat, 103-big arm, 104-shoulder joint, 105-small arm component, 106-wrist, 107-end flange, 2-adapter frame, 3-small arm, 301-housing, 302-third stage big gear, 303-third stage small gear, 304-power input gear shaft, 305-middle tooth meshing, 306-top tooth meshing, 4-fixed beam, 5-test torque Crossbeam, 501-test rod, 6-load plate, 7-counterweight cylinder, 8-measuring instrument, 801-magnetic base, 802-micrometer bracket, 803-micrometer, 804-needle, 9-locking mechanism, 901-locking plate, 902-locking shaft, 903-key, 904-manual toggle screw, 905-locking screw, 906-locating pin, 907-arc waist hole, 908-flat washer, 909-spring washer, 10-positioner, 1001-positioning rotating plate. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] See also Figure 1As shown, the large load robot is generally a six-degree-of-freedom vertical multi-joint industrial robot 1, which includes a base 101, a waist seat 102, an upper arm 103, a shoulder joint 104, a forearm component 105, a wrist 106 and an end flange 107. There are driven axes between two adjacent components of the seven components, including one axis between the base 101 and the waist seat 102, two axes between the waist seat 102 and the upper arm 103, three axes between the upper arm 103 and the shoulder joint 104, four axes between the shoulder joint 104 and the forearm component 105, five axes between the forearm 105 and the wrist 106, and six axes between the wrist 106 and the end flange 107. The above six axes are defined axes in the robot control mathematical model. The forearm component 105 includes a forearm 3, and the motion output end of the forearm 3 contains a fifth axis mechanical interface connected to the wrist 106.

[0036] See also Figures 2 to 4 As shown, an embodiment of the present invention provides a large-load robot transmission stiffness calibration device, including an adapter frame 2, a fixed beam 4, a test torque beam 5, a counterweight mechanism, a measuring instrument 8, a locking mechanism 9 and a positioner 10, wherein the adapter frame 2 is connected to the positioner rotating disk 1001 of the positioner 10, the robot joint to be calibrated is installed on the adapter frame 2, and the output shaft of the robot joint to be calibrated is coaxial with the positioner rotating disk 1001, and the input shaft of the robot joint to be calibrated is locked by the locking mechanism 9; the middle part of the test torque beam 5 is connected to the output shaft of the robot joint to be calibrated, and the two ends of the test torque beam 5 are respectively connected to two sets of counterweight mechanisms, and initial leveling is performed by the two sets of counterweight mechanisms; the fixed beam 4 is connected to the output end housing of the robot joint to be calibrated, the measuring instrument 8 is arranged at one end of the fixed beam 4, and loading is performed at the other end of the fixed beam 4, and the torsion angle of the test torque beam 5 is measured by the measuring instrument 8, thereby realizing the stiffness calibration of the robot joint.

[0037] See also Figure 2 As shown, in the embodiment of the present invention, the positioner 10 is preferably a single-axis L-type positioner, the bottom of the positioner 10 is connected to the ground, the rotating axis of the positioner rotating disk 1001 is parallel to the ground and is colinear with the fifth axis of the forearm 3.

[0038] See also Figure 2 As shown, in the embodiment of the present invention, the weight balancing mechanism includes a configuration cylinder 7, the weight balancing cylinder 7 is suspended at the end of the test torque beam 5, and a fixed mass of weight medium is added to the weight balancing cylinder 7. In this embodiment, a fixed mass of water is added to the weight balancing cylinder 7 to perform initial gravity bending moment balancing, that is, to test that the torque beam 5 is relatively level with the ground in a free state.

[0039] Further, the upper parts of both ends of the test torque beam 5 are provided with test rods 501, and the test rods 501 are used to set the load disks 6 of a certain mass, and different masses are loaded by different numbers of load disks 6. In this embodiment, the load disk 6 is a discus with a center hole. The middle part of the test torque beam 5 is designed as a part of the fifth axis mechanical interface, and then the middle part of the test torque beam 5 is connected to the motion output end (output shaft) of the forearm 3.

[0040] See also Figure 3 As shown, in an embodiment of the present invention, the measuring instrument 8 includes a magnetic base 801, a micrometer bracket 802 and a micrometer 803, wherein one end of the micrometer bracket 802 is fixedly connected to the magnetic base 801, and the micrometer 803 is installed on the other end; the magnetic base 801 is magnetically attracted to the fixed beam 4, the micrometer 803 is located above the test torque beam 5, and the needle 804 of the micrometer 803 is in contact with the test torque beam 5.

[0041] See also Figure 5 , Figure 6 As shown, in the embodiment of the present invention, the locking mechanism 9 includes a locking disk 901 and a locking shaft 902, wherein the locking disk 901 is symmetrically provided with two arc-shaped waist holes 907, and the two arc-shaped waist holes 907 are located on the same circumference. One end of the locking shaft 902 is positioned with the locking disk 901 through a positioning pin 906, and is fixed to the center of the locking disk 901 through a plurality of locking screws 905, and the other end of the locking shaft 902 is connected to the input shaft of the robot joint to be calibrated through a key 903, and the locking disk 901 is connected to the input end housing of the robot joint to be calibrated through two manual dial screws 904 respectively accommodated in the two arc-shaped waist holes 907. When it is necessary to adjust the position of the input shaft of the robot joint to be calibrated, loosen the manual dial screw 904, rotate the locking disk 901 through the manual dial screw 904, and then drive the input shaft of the robot joint to be calibrated to rotate to any position through the locking shaft 902, and tighten the manual dial screw 904 after adjusting the angle to complete the locking of the input shaft of the robot joint to be calibrated.

[0042] In this embodiment, the robot joint to be calibrated is the arm 3 of a six-degree-of-freedom vertical multi-joint industrial robot 1, and the internal transmission of the arm 3 is a three-stage gear reduction box configuration. Figure 6 , Figure 8As shown, the three-stage gear reduction box includes a housing 301 and a three-stage gear transmission arranged in the housing 301, the first-stage gear transmission is connected to the power input gear shaft 304, the three-stage gear transmission includes a third-stage large gear 302 and a third-stage small gear 303 that mesh with each other, and the third-stage large gear 302 is connected to the output shaft. The servo motor housing in the arm 3 is fixed on the housing 301 in application, and the servo motor output shaft in the arm 3 is relatively fixed to the power input gear shaft 304 in application. The power input gear shaft 304 is locked at any position by the locking mechanism 9, and the power input gear shaft 304 can be locked at any angle relative to the housing 301.

[0043] Furthermore, the locking plate 901 is rotated to any position, and at least two screw holes provided on the housing 301 are exposed in the two arc-shaped waist holes 907. In this embodiment, the distribution angle of the arc-shaped waist holes 907 relative to the center is 95°. When the locking plate 901 is rotated to the required angle for the stiffness test, the screw 904 is manually turned through the two sets of spring washers 909 and flat washers 908 and the corresponding arc-shaped waist holes 907 to lock the rotating plate 901 and the housing 301, thereby locking the power input gear shaft 304 relative to the housing 301 of the three-stage gear reduction box at any angle.

[0044] The present invention provides a large-load robot transmission stiffness calibration device, and its working principle is:

[0045] During bending moment loading, multiple discus with center holes are placed on the test rod 501 at one end of the test torque beam 5, or water is released or pumped out of the counterweight cylinder 7 to achieve positive loading or unloading, reverse loading or unloading of the output shaft of the forearm 3, and calibrate the required torque test dimension Nm.

[0046] In the torsional stiffness test, the fixed beam 4 is fixed to the housing 301 of the three-stage gear reducer, the magnetic base 801 of the measuring instrument is adsorbed to the appropriate position of the fixed beam 4, and the spatial position of the micrometer bracket 802 is adjusted so that the needle 804 of the micrometer 803 is in vertical contact with the specific position of the test torque beam 5, so as to measure the displacement, and the torsion angle of the test torque beam 5 can be obtained through the measured displacement. Specifically, through the relative position of the specific position of the test torque beam 5 and the housing 301 of the three-stage gear reducer and the reading of the micrometer 803, the robot measurement professional will convert the torsion angle test dimension arc.min.

[0047] See also Figure 8 As shown in (a), the robot arm is calibrated in the positive position, for the housing 301, the third-stage large gear 302 and the third-stage small gear 303 of the three-stage gear reducer, wherein the third-stage large gear 302 is relatively fixed to the ground, and the third-stage large gear 302 and the third-stage small gear 303 are meshed in the middle of the teeth 305. Figure 8As shown in (b), the robot arm is calibrated in a non-positive position. If the third-stage large gear 302 and the third-stage small gear 303 are in different relative positions to the ground, some are close to the tooth root, and some are close to the tooth top, that is, the tooth top meshes 306. Therefore, the meshing phase is different, and the meshing stiffness is also different. Therefore, the present invention has the ability to calibrate the stiffness curve of the gear of the fifth-axis gearbox configuration of the large-load robot at different meshing phases, thereby improving the optimization strategy database of the control stiffness model and the vibration model.

[0048] Another embodiment of the present invention provides a calibration method using the large-load robot transmission stiffness calibration device in any of the above embodiments, the calibration method comprising the following steps:

[0049] Step S1: Install the robot joint to be calibrated on the positioner 10;

[0050] First, install the adapter frame 2 on the position changing rotating disk 1001 of the position changing machine 10, then connect the input end housing of the robot joint to be calibrated to the adapter frame 2, and make the axis of the output shaft of the robot joint to be calibrated collinear with the axis of the position changing rotating disk 1001;

[0051] Step S2: the positioner 10 adjusts the angle of the position-changing rotating disk 1001 to align the adapter frame 2 and level it with a level ruler;

[0052] Step S3: The middle part of the test torque beam 5 is connected to the output shaft of the robot joint to be calibrated, and the test torque beam 5 is leveled with a level ruler, and then the input shaft of the robot joint to be calibrated is locked by the locking mechanism 9;

[0053] Step S4: Connect the fixed beam 4 to the output end housing of the robot joint to be calibrated, and install the measuring instrument on the fixed beam 4;

[0054] Step S5: Load is applied step by step at one end of the test torque beam 5, and the torsion angle is measured step by step at the other end of the test torque beam 5 by a measuring instrument; then the load is removed step by step and the torsion angle change is measured step by step;

[0055] Load is applied step by step at the other end of the test torque beam 5, and the reverse torsion angle is measured step by step by a measuring instrument; then the load is removed step by step, and the reverse torsion angle change is measured step by step, so as to obtain the first stiffness hysteresis closed-loop curve of the first phase of the transmission gear meshing of the robot joint to be calibrated;

[0056] Step S6: the positioner 10 adjusts the position rotation disk 1001 to step the preset angle, unlocks the locking mechanism (9), rotates the input shaft of the robot joint to be calibrated, keeps the test torque beam (5) in a horizontal state, and levels it with a level ruler;

[0057] Step S7: executing step S5 to obtain a second stiffness hysteresis curve of the second phase of the transmission gear meshing of the robot joint to be calibrated;

[0058] Step S8: Repeat steps S6 and S7 to obtain multiple transmission stiffness hysteresis curves, and perform data processing and analysis to obtain values ​​such as backlash and idle stroke of each gear meshing phase as a control system stiffness database.

[0059] The invention provides a large-load robot transmission stiffness calibration device, which has a simple structure and can use existing robot joints and joint arms to test joint stiffness without adding additional tooling; on the one hand, it can effectively control errors and make the test results more accurate; on the other hand, it uses existing positioners, with less investment and more cost savings. The method of the invention is simple to operate, can effectively and quickly test the stiffness of robot joints, and has high test accuracy.

[0060] The above description is only an embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, expansion, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A large load robot transmission stiffness calibration device, characterized in that: The invention comprises an adapter frame (2), a fixed beam (4), a test torque beam (5), a counterweight mechanism, a measuring instrument (8), a locking mechanism (9) and a positioner (10), wherein the adapter frame (2) is connected to a positioner rotating disk (1001) of the positioner (10), the robot joint to be calibrated is mounted on the adapter frame (2), the output shaft of the robot joint to be calibrated is coaxial with the positioner rotating disk (1001), and the input shaft of the robot joint to be calibrated is locked by the locking mechanism (9); the middle part of the test torque beam (5) is connected to the output shaft of the robot joint to be calibrated, and the two ends of the test torque beam (5) are respectively connected to two sets of counterweight mechanisms; the fixed beam (4) is connected to the output end housing of the robot joint to be calibrated, the measuring instrument (8) is arranged at one end of the fixed beam (4), loading is performed at one end of the test torque beam (5) away from the measuring instrument (8), and the torsion angle of the test torque beam (5) is measured by the measuring instrument (8), thereby realizing the stiffness calibration of the robot joint.

2. The large-load robot transmission stiffness calibration device according to claim 1, characterized in that: The counterweight mechanism comprises a configuration cylinder (7), the counterweight cylinder (7) is suspended at the end of the test torque beam (5), and a counterweight medium of a fixed mass is added into the counterweight cylinder (7).

3. The large-load robot transmission stiffness calibration device according to claim 1, characterized in that: The upper parts of both ends of the test torque crossbeam (5) are provided with test rods (501), and the test rods (501) are used to fit load plates (6) of a certain mass, so that loading of different masses can be achieved through different numbers of load plates (6).

4. The large-load robot transmission stiffness calibration device according to claim 1, characterized in that: The measuring instrument (8) comprises a magnetic base (801), a dial gauge bracket (802) and a dial gauge (803), wherein one end of the dial gauge bracket (802) is fixedly connected to the magnetic base (801), and the dial gauge (803) is installed at the other end; the magnetic base (801) is magnetically attracted to the fixed beam (4), the dial gauge (803) is located above the test torque beam (5), and the needle (804) of the dial gauge (803) is in contact with the test torque beam (5).

5. The large-load robot transmission stiffness calibration device according to claim 1, characterized in that: The locking mechanism (9) comprises a locking disk (901) and a locking shaft (902), wherein the locking disk (901) is symmetrically provided with two arc-shaped waist holes (907), the locking shaft (902) is fixed at the center of the locking disk (901), the locking shaft (902) is connected to the input shaft of the robot joint to be calibrated via a key (903), and the locking disk (901) is connected to the input end housing of the robot joint to be calibrated via two manual toggle screws (904) respectively accommodated in the two arc-shaped waist holes (907).

6. The large-load robot transmission stiffness calibration device according to claim 1, characterized in that: The robot joint to be calibrated is the forearm (3) of a six-degree-of-freedom vertical multi-joint industrial robot (1).

7. A calibration method using the large-load robot transmission stiffness calibration device according to any one of claims 1 to 6, characterized in that: The calibration method comprises the following steps: Step S1: installing the robot joint to be calibrated on a positioner (10); First, the adapter frame (2) is installed on the position changing rotating disk (1001) of the position changing machine (10), and then the input end housing of the robot joint to be calibrated is connected to the adapter frame (2), and the axis of the output shaft of the robot joint to be calibrated is aligned with the axis of the position changing rotating disk (1001); Step S2: the positioner (10) adjusts the angle of the positioner rotating disk (1001) to align the adapter frame (2) and level it using a level ruler; Step S3: The middle part of the test torque beam (5) is connected to the output shaft of the robot joint to be calibrated, the counterweight mechanism is connected to both ends of the test torque beam (5), and the test torque beam (5) is leveled by a level ruler, and then the input shaft of the robot joint to be calibrated is locked by a locking mechanism (9); Step S4: Connect the fixed crossbeam (4) to the output end housing of the robot joint to be calibrated, and install the measuring instrument on the fixed crossbeam (4); Step S5: loading a load step by step at one end of the test torque beam (5), and measuring the torsion angle step by step at the other end of the test torque beam (5) by using a measuring instrument; then removing the load step by step, and measuring the change of the torsion angle step by step; Loads are applied step by step at the other end of the test torque beam (5), and the reverse torsion angle is measured step by step by a measuring instrument; then the loads are removed step by step, and the change of the reverse torsion angle is measured step by step; Obtaining a first stiffness hysteresis closed-loop curve of a first phase of a transmission gear meshing of a robot joint to be calibrated; Step S6: the positioner (10) adjusts the positioner rotating disk (1001) to step by a preset angle, unlocks the locking mechanism (9), rotates the input shaft of the robot joint to be calibrated, keeps the test torque beam (5) in a horizontal state, and levels it with a level ruler; Step S7: executing step S5 to obtain a second stiffness hysteresis curve of the second phase of the transmission gear meshing of the robot joint to be calibrated; Step S8: Repeat steps S6 and S7 to obtain multiple transmission stiffness hysteresis curves, and perform data processing and analysis.

Images