A space robot ground microgravity crawling test system

Abstract

A space robot ground microgravity climbing test system, the lower end of the outer frame is fixed on the ground, the upper end is provided with X / Z axis gravity compensation module and Y axis gravity compensation module, the centroid following module is fixed with the suspension rope in the X / Z axis gravity compensation module through the tension sensor, and the lower end is fixed with the space climbing robot through the universal joint and spherical hinge, the space climbing robot performs space microgravity climbing test on the target simulator, the target simulator is placed on the ground through the universal wheel, when the robot climbs, the target simulator moves in X / Y and rotates around Z axis under the reaction force, so as to provide three degrees of freedom space microgravity simulation conditions. Meanwhile, the X / Z axis gravity compensation module and the Y axis gravity compensation module can realize the autonomous following of the space climbing robot in X / Y / Z three directions, and the centroid following module can realize that the centroid of the robot is always on the extension line of the suspension point when the robot changes the posture and configuration.

Description

TECHNICAL FIELD

[0001] The present application relates to a space robot ground microgravity crawling test system, belonging to the field of space microgravity environment simulation test. BACKGROUND

[0002] Large spacecraft is a high-value space equipment for space resource utilization and scientific exploration, and on-orbit servicing is the key to ensure its long-term stable operation in orbit. However, the current typical tasks such as extravehicular emergency fault handling and routine inspection and maintenance still rely on astronauts' extravehicular activities, which has the problems of high risk, poor real-time performance and long cycle. The ability to replace astronauts to realize on-orbit inspection of large spacecraft covering the whole area is urgently needed. In view of the large-scale reaching in the extravehicular multi-obstacle environment, developing space crawling robot technology is a necessary way to improve the on-orbit servicing and maintenance capability of large spacecraft. Its core is to adapt to the complex structure of spacecraft, have multi-mode motion planning and control capability and low-energy consumption driving capability. In order to verify the above key capabilities, a ground microgravity crawling test system needs to be developed to provide conditions for space robot ground verification.

[0003] The scientific literature "Design and Implementation of Space Robot Ground Test Platform Based on Air-floating Mode" (Modern Machinery, Vol. 3, No. 1, June 2007) introduces a test platform that realizes space robot ground microgravity simulation test with air-floating as the gravity compensation mode, but this platform can only realize the gravity compensation microgravity simulation motion of space robots in two-dimensional plane. A multi-target six-degree-of-freedom microgravity ground simulation system and its use method in Chinese patent CN113264203B are composed of a high-rigidity gantry, a discrete guide system, a six-degree-of-freedom simulation platform and a motion measurement system. This system uses an external measurement system to obtain the spatial pose of the hoisted object in the system. However, the surface structure of a space large spacecraft is complex and there are a large number of occluded areas, so the external visual measurement is easy to lose the hoisted object, and therefore the scene of space robot crawling on the complex surface of a large spacecraft cannot be completely simulated. A space microgravity environment ground simulation experiment device in Chinese patent CN103466109A is composed of a foundation, two support columns, a transverse air-floating guide rail, a longitudinal air-floating guide rail, a trolley and a weightlessness simulation control system. This system uses a single-point suspension fixed point. However, the attitude and configuration of a space crawling robot will change during the crawling process, resulting in time-varying of the center of mass. Using a fixed-point suspension will cause the space crawling robot to overturn due to the gravity deflection torque, and therefore cannot meet the use requirements. SUMMARY

[0004] The technical problem to be solved by the present application is to overcome the shortcomings of the prior art and provide a space robot ground microgravity crawling test system. The system has the advantages of not relying on external measurement data to realize three-dimensional gravity compensation following and can avoid the overturning risk caused by the change of the center of mass of the suspended robot.

[0005] The application aims to realize the following technical solutions.

[0006] A space robot ground microgravity climbing test system comprises an outer frame, an X / Z-axis gravity compensation module, a Y-axis gravity compensation module, a center of mass following module and a target simulator; the lower end of the outer frame is fixed on the ground, and the upper end is provided with the X / Z-axis gravity compensation module and the Y-axis gravity compensation module; the center of mass following module is fixed on the upper end of the X / Z-axis gravity compensation module through a tension sensor and a suspension rope, and is fixed on the lower end of the space climbing robot through a universal joint and a spherical hinge; the upper end of the target simulator is provided with the space climbing robot, and the lower end is placed on the ground through a universal wheel.

[0007] The outer frame is used for providing support and transmission capacity for the whole system.

[0008] The X / Z-axis gravity compensation module and the Y-axis gravity compensation module are used for keeping the position of the suspension rope following the robot in three directions.

[0009] The center of mass following module is used for adjusting the suspension point position when the robot posture and configuration are changed, so that the suspension always passes through the center of mass of the robot.

[0010] The space climbing robot is used for providing a suspension target and feeding back the joint angle of the robot to a robot control computer.

[0011] The target simulator is used for providing a three-degree-of-freedom passive microgravity simulation environment.

[0012] Further, the outer frame comprises a support truss, a Y-axis moving guide rail, a Y-axis moving rack, an X-axis moving support beam, an X-axis moving guide rail and an X-axis moving rack; the lower end of the support truss is fixed on the ground, and the upper end is provided with the Y-axis moving guide rail and the Y-axis moving rack in parallel; the lower end of the X-axis moving support beam is fixed on the Y-axis gravity compensation base, and the upper end is provided with the X-axis moving guide rail and the X-axis moving rack; the Y-axis moving rack is engaged with a Y-axis gravity compensation gear, the Y-axis moving guide rail is provided with a Y-axis gravity compensation sliding block, the X-axis moving rack is engaged with an X-axis gravity compensation gear, and the X-axis moving guide rail is provided with an X-axis gravity compensation sliding block.

[0013] Further, the X / Z-axis gravity compensation module comprises an X-axis gravity compensation servo motor, an X-axis gravity compensation reducer, a first rope outlet small pulley, a rope outlet rear limiting plate, a winding motor module, a winding wheel, an X / Z-axis gravity compensation base, a tension sensor module, an X-axis gravity compensation gear, a laser displacement sensor, a Y-axis tension compensation spring, a Y-axis compression compensation spring, a rope outlet moving base, an X-axis gravity compensation slider, a Y-axis rope outlet compensation slider, a Y-axis rope outlet compensation guide rail, a suspension rope, a rope outlet front limiting plate, a Hall angle sensor, a second rope outlet small pulley, a rope outlet rotating block, a rope outlet limiting hole shaft, a rope outlet large pulley, and an X / Z-axis gravity compensation control module. The upper end of the X-axis gravity compensation reducer is connected with the X-axis gravity compensation servo motor, the lower end of the X-axis gravity compensation reducer is fixed on the X / Z-axis gravity compensation base together with the rope outlet rear limiting plate, the Z-axis winding motor module, the X-axis gravity compensation slider, the rope outlet compensation guide rail, the rope outlet front limiting plate, and the X / Z-axis gravity compensation control module, and meanwhile, the output shaft of the X-axis gravity compensation reducer is connected with the X-axis gravity compensation gear in tight fit. One end of the suspension rope is fixed on the winding wheel connected with the winding motor module, then passes through the pulley fixed in the tension sensor module of the rope outlet rear limiting plate to the first rope outlet small pulley, then to the rope outlet large pulley fixed on the rope outlet moving base, then through the rope outlet limiting hole shaft and the second rope outlet small pulley fixed on the rope outlet rotating block, and finally the other end of the suspension rope is connected with the tension sensor in the center-of-mass following module.

[0014] Further, the Y-axis gravity compensation module comprises a Y-axis gravity compensation servo motor, a Y-axis gravity compensation reducer, a Y-axis gravity compensation gear, a Y-axis gravity compensation control module, a Y-axis gravity compensation base, and a Y-axis gravity compensation slider. The upper end of the Y-axis gravity compensation reducer is fixedly connected with the Y-axis gravity compensation servo motor, the lower end of the Y-axis gravity compensation reducer is fixed on the Y-axis gravity compensation base together with the Y-axis gravity compensation control module, and meanwhile, the Y-axis gravity compensation gear is connected with the output shaft of the Y-axis gravity compensation reducer.

[0015] Further, the center-of-mass following module includes a center-of-mass following upper plate, an upper-and-lower plate connecting column, a center-of-mass following lower plate, a spherical hinge, a spherical hinge connecting column, an X / Y direction steering engine, an X axis guide rail fixed plate, a guide rail bearing, a synchronous pulley, a synchronous belt, a Y axis guide rail, a suspension fixed block, a Z direction linear steering engine, a tension sensor, a universal joint, a universal joint connecting column, a synchronous belt fixed sliding block, a steering engine fixed plate, a steering engine connecting flange, an X axis guide rail, a Y guide rail fixed plate, and a suspension fixed block moving guide rail. The center-of-mass following upper plate is connected with the center-of-mass following lower plate through the upper-and-lower plate connecting column, the X / Y direction steering engine is connected with the center-of-mass following lower plate through the steering engine fixed plate and connected with the synchronous pulley through the steering engine connecting flange, the synchronous pulley is connected with the X axis guide rail and the Y axis guide rail through tight fitting, the X axis guide rail fixed plate and the Y guide rail fixed plate are both connected with the center-of-mass following lower plate, the X axis guide rail fixed plate is fixedly connected with the X axis guide rail through the guide rail bearing, and the Y guide rail fixed plate is fixedly connected with the Y axis guide rail through the guide rail bearing, two synchronous belt fixed sliding blocks are arranged in the X and Y directions respectively, the synchronous belt fixed sliding blocks in the X and Y directions are driven by the synchronous belts in the X and Y directions to move along the X axis guide rail and the Y axis guide rail, one end of the suspension fixed block moving guide rail is connected with the synchronous belt fixed sliding block, and the other end is connected with the suspension fixed block, so that when the synchronous belt fixed sliding block moves, the suspension fixed block also moves correspondingly, the Z direction linear steering engine is fixedly connected with the suspension fixed block, and the output shaft is connected with the tension sensor, the universal joint connecting column is connected with the center-of-mass following upper plate and the space crawling robot through the universal joint at both ends, and the other three spherical hinge connecting columns are connected with the center-of-mass following upper plate and the space crawling robot through the spherical hinge at both ends, which can make the center-of-mass following module only change in the pitch and roll directions and limit the roll degree of freedom around the vertical axis, and can also avoid excessive constraint and cause module motion interference.

[0016] Further, the space robot ground microgravity crawling test system further includes a robot control computer, a wireless communication module, and a ground test system console.

[0017] The robot control computer calculates the control amount of each joint rotation of the robot according to the crawling motion trajectory, then sends a control motion instruction to the space crawling robot through the wireless communication module to control the space crawling robot to crawl on the target spacecraft according to the specified path, collects the angle information of each leg joint of the space crawling robot, then obtains the position of the center of mass of the robot through the angle and center-of-mass corresponding relationship, and then sends the position to the ground test system console through the wireless communication module.

[0018] The ground test system console 3 receives the center of mass position information sent by the robot control computer 1 through the wireless communication module 2, calculates the movement angle of the three direction motors of the center of mass tracking module 7, and then sends the movement angle to the X / Y direction steering wheel 7-6 and the Z direction linear steering wheel 7-13 to control the change of the hanging point position of the suspension rope 5-17, so as to change the structure of the parallel hanger in real time, ensure that the center of mass of the robot is always on the extension line of the suspension rope 5-17, and collect the data of the tension sensor 7-14, the Hall angle sensor 5-19 and the laser displacement sensor 5-10, calculate the position of the hanging point, and then send the corresponding control amount to the X / Z axis gravity compensation control module 5-24 and the Y axis gravity compensation control module 6-4, and then control the X / Z axis gravity compensation control module 5-24 to control the X axis gravity compensation servo motor 5-1 and the Z axis rope winding motor module 5-5 to act, and the Y axis gravity compensation control module 6-4 controls the Y axis gravity compensation servo motor 6-1 to act, so as to drive the X / Z axis gravity compensation module to move along the X axis, the Y axis and the Z axis, and the Y axis tension compensation spring 5-11 and the Y axis compression compensation spring 5-12 fixed on the rope outlet limiting plate 5-4 move the rope outlet base 5-13 to the balance position under the antagonistic action of tension / pressure, and adjust the tension of the suspension rope 5-17 to the gravity compensation value.

[0019] Compared with the prior art, the present application has the following beneficial effects:

[0020] (1) The present application uses internal sensors to obtain the position of the robot, and then controls the gravity compensation to follow in real time, which reduces the external measuring equipment, reduces the overall cost of the system, avoids the risk of loss of measurement data due to shielding and loss of control of gravity tracking, and improves the real-time following frequency.

[0021] (2) The present application uses a suspension rope to connect the robot through a parallel similar hanger, which can passively and autonomously realize the tracking effect of the robot posture compared with the fixed suspension in the prior art, and eliminate the gravity deflection torque caused by the change of the robot posture when the single rope is suspended.

[0022] (3) The present application uses a center of mass following module to replace the fixed hanging point in the prior art, which can change the structure of the parallel hanger in real time during the robot crawling process, ensure that the center of mass of the robot is always on the extension line of the suspension rope, and eliminate the gravity deflection torque caused by the change of the center of mass. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The figure is a system configuration diagram in the embodiment of the present application.

[0024] Figure 2 The figure is a schematic view of the outer frame module in the embodiment of the present application.

[0025] Figure 3 Figure 5 is a schematic diagram of a gravity compensation module in the embodiment of the present application.

[0026] Figure 4 Figure 6 is a schematic diagram of a Y-axis gravity compensation module in the embodiment of the present application.

[0027] Figure 5 Figure 7 is a schematic diagram of a center-of-mass following module in the embodiment of the present application.

[0028] Figure 6 Figure 8 is a schematic diagram of a force on the center-of-mass following module in the embodiment of the present application.

[0029] Reference signs: robot control computer-1, wireless communication module-2, ground test system console-3, outer frame-4, X / Z axis gravity compensation module-5, Y axis gravity compensation module-6, center of mass following module-7, space crawling robot-8, target simulator-9, support truss-4-1, Y axis moving guide rail-4-2, Y axis moving rack-4-3, X axis moving support beam-4-4, X axis moving guide rail-4-5, X axis moving rack-4-6, X axis gravity compensation servo motor-5-1, X axis gravity compensation reducer-5-2, first rope outlet small pulley-5-3, rope outlet rear limiting plate-5-4, rope winding motor module-5-5, rope winding wheel-5-6, X / Z axis gravity compensation base-5-7, tension sensor module-5-8, X axis gravity compensation gear-5-9, laser displacement sensor-5-10, Y axis tension compensation spring-5-11, Y axis compression compensation spring-5-12, rope outlet moving base-5-13, X axis gravity compensation slider-5-14, Y axis rope outlet compensation slider-5-15, Y axis rope outlet compensation guide rail-5-16, suspension rope-5-17, rope outlet front limiting plate-5-18, Hall angle sensor-5-19, second rope outlet small pulley-5-20, rope outlet rotating block-5-21, rope outlet limiting hole shaft-5-22, rope outlet large pulley-5-23, X / Z axis gravity compensation control module-5-24, Y axis gravity compensation servo motor-6-1, Y axis gravity compensation reducer-6-2, Y axis gravity compensation gear-6-3, Y axis gravity compensation control module-6-4, Y axis gravity compensation base-6-5, Y axis gravity compensation slider-6-6, center of mass following upper plate-7-1, upper and lower plate connecting column-7-2, center of mass following lower plate-7-3, spherical hinge-7-4, spherical hinge connecting column-7-5, X / Y direction steering engine-7-6, X axis guide rail fixed plate-7-7, shaft guide rail bearing-7-8, synchronous pulley-7-9, synchronous belt-7-10, Y axis guide rail-7-11, suspension fixed block-7-12, Z direction linear steering engine-7-13, tension sensor-7-14, universal joint-7-15, universal joint connecting column-7-16, synchronous belt fixed slider-7-17, steering engine fixed plate-7-18, steering engine connecting flange-7-19, X axis guide rail-7-20, Y guide rail fixed plate-7-21, suspension fixed block moving guide rail-7-22. DETAILED DESCRIPTION

[0030] In order to make the objectives, technical solutions and advantages of the present application clearer, the embodiments of the present application will be further described in detail below with reference to the drawings.

[0031] As Figure 1As shown, a microgravity crawling test system for a space robot includes a robot control computer 1, a wireless communication module 2, a ground test system control console 3, an outer frame 4, an X / Z axis gravity compensation module 5, a Y axis gravity compensation module 6, a center of mass following module 7, and a target simulator 9. The lower end of the outer frame 4 is fixed to the ground, and the X / Z axis gravity compensation module 5 and the Y axis gravity compensation module 6 are installed on the upper end. The center of mass following module 7 is fixed to the suspension rope 5-17 of the X / Z axis gravity compensation module 5 via its own tension sensor 7-14, and the lower end is connected via... Universal joint 5-12 and ball joint 5-4 are fixedly connected to the space crawling robot 8. The space crawling robot 8 conducts a microgravity crawling experiment on the target simulator 9. The target simulator 9 is placed on the ground via universal wheels. When the robot crawls, it generates a reaction force on the target simulator 9. Since the target simulator 9 is unconstrained with the ground, it will undergo X / Y movement and rotation around the Z axis under the reaction force. When the friction between the ground and the target simulator is ignored, the target simulator can be considered to have three degrees of freedom in space microgravity simulation capability in X / Y movement and Z rotation. The definition of the three axes can be found in the example. Figure 1 The origin is fixed at the lower right corner of the ground directly opposite the frame. The X-axis direction is from the origin along the outer edge of the frame to the left. The Z-axis direction is from the origin along the outer edge of the frame perpendicular to the ground. The Y-axis follows the right-hand rule.

[0032] like Figure 2 As shown, the outer frame 4 of this invention includes a support truss 4-1, a Y-axis moving guide rail 4-2, a Y-axis moving rack 4-3, an X-axis moving support beam 4-4, an X-axis moving guide rail 4-5, and an X-axis moving rack 4-6. The lower end of the support truss 4-1 is fixed to the ground, and the upper end is equipped with the Y-axis moving guide rail 4-2 and the Y-axis moving rack 4-3 side by side. The lower end of the X-axis moving support beam 4-4 is fixed to the Y-axis gravity compensation base 6-5, and the upper end is equipped with the X-axis moving guide rail 4-5 side by side. X-axis moving rack 4-6; Y-axis moving rack 4-3 meshes with Y-axis gravity compensation gear 6-3, Y-axis gravity compensation slider 6-6 is installed on Y-axis moving guide rail 4-2, X-axis moving rack 4-6 meshes with X-axis gravity compensation gear 5-9, X-axis gravity compensation slider 5-14 is installed on X-axis moving guide rail 4-5. When the corresponding gravity compensation motor rotates, the corresponding slider moves on the guide rail through the reducer and gear rack transmission to achieve gravity compensation position adjustment.

[0033] like Figure 3As shown, the X / Z axis gravity compensation module 5 of the application includes an X axis gravity compensation servo motor 5-1, an X axis gravity compensation reducer 5-2, a first rope outlet small pulley 5-3, a rope outlet rear limiting plate 5-4, a winding motor module 5-5, a winding wheel 5-6, an X / Z axis gravity compensation base 5-7, a tension sensor module 5-8, an X axis gravity compensation gear 5-9, a laser displacement sensor 5-10, a Y axis tension compensation spring 5-11, a Y axis compression compensation spring 5-12, a rope outlet moving base 5-13, an X axis gravity compensation slider 5-14, a Y axis rope outlet compensation slider 5-15, a Y axis rope outlet compensation guide rail 5-16, a suspension rope 5-17, a rope outlet front limiting plate 5-18, a Hall angle sensor 5-19, a second rope outlet small pulley 5-20, a rope outlet rotating block 5-21, a rope outlet limiting hole shaft 5-22, a rope outlet large pulley 5-23, and an X / Z axis gravity compensation control module 5-24. The upper end of the X axis gravity compensation reducer 5-2 is connected with the X axis gravity compensation servo motor 5-1, and the lower end of the X axis gravity compensation reducer 5-2 and the rope outlet rear limiting plate 5-4, the Z axis winding motor module 5-5, the X axis gravity compensation slider 5-14, the rope outlet compensation guide rail 5-16, the rope outlet front limiting plate 5-18, and the X / Z axis gravity compensation control module 5-24 are all fixed on the X / Z axis gravity compensation base 5-7 (among them, the components fixed on the upper surface of the X / Z axis gravity compensation base 5-7 are the lower end of the X axis gravity compensation reducer 5-2 and the rope outlet rear limiting plate 5-4, the Z axis winding motor module 5-5, the rope outlet compensation guide rail 5-16, and the X / Z axis gravity compensation control module 5-24; the components fixed on the lower surface of the X / Z axis gravity compensation base 5-7 are the X axis gravity compensation slider 5-14; and the components fixed on the front surface of the X / Z axis gravity compensation base 5-7 are the rope outlet front limiting plate 5-18), and meanwhile, the output shaft of the X axis gravity compensation reducer 5-2 is connected with the X axis gravity compensation gear 5-9 in over-tight fitting. One end of the suspension rope 5-17 is fixed on the winding wheel 5-6 connected with the winding motor module 5-5, then passes through the pulley in the tension sensor module 5-8 fixed on the rope outlet rear limiting plate 5-4 to the first rope outlet small pulley 5-3, then to the rope outlet large pulley 5-23 fixed on the rope outlet moving base 5-13, then through the rope outlet limiting hole shaft 5-22 and the second rope outlet small pulley 5-20 fixed on the rope outlet rotating block 5-21, and finally the other end of the suspension rope 5-17 is connected with the tension sensor 7-14 in the center of mass following module 7.In the Y-axis direction, the suspension rope 5-17 will cause the Y-axis out- rope compensation slider 5-15 fixed with the out- rope moving base 5-13 to move on the Y-axis out- rope compensation guide rail 5-16, at this time the laser displacement sensor 5-10 fixed on the out- rope rear limiting plate 5-4 will collect the Y-axis movement value, and then feedback to the ground test system console 3, then the ground test system console 3 calculates the movement amount of the Y-axis gravity compensation module 6, and then sends the control data to the Y-axis gravity compensation control module 6-4 to control the Y-axis gravity compensation servo motor 6-1 to act, drive the X / Z-axis gravity compensation module to move along the Y-axis, at the same time, the Y-axis tension compensation spring 5-11 and the Y-axis compression compensation spring 5-12 fixed on the out- rope rear limiting plate 5-4 will move the out- rope moving base 5-13 to the balance position under the antagonistic action of tension / pressure.

[0034] As shown in Figure 4 The Y-axis gravity compensation module 6 of the present application includes a Y-axis gravity compensation servo motor 6-1, a Y-axis gravity compensation reducer 6-2, a Y-axis gravity compensation gear 6-3, a Y-axis gravity compensation control module 6-4, a Y-axis gravity compensation base 6-5 and a Y-axis gravity compensation slider 6-6; the upper end of the Y-axis gravity compensation reducer 6-2 is fixed with the Y-axis gravity compensation servo motor 6-1, the lower end is fixed on the Y-axis gravity compensation base 6-5 together with the Y-axis gravity compensation control module 6-4, and at the same time, the Y-axis gravity compensation gear 6-3 is connected with the output shaft of the Y-axis gravity compensation reducer 6-2.

[0035] As shown in Figure 5As shown, the centroid following module 7 of the application includes a centroid following upper plate 7-1, an upper and lower plate connecting column 7-2, a centroid following lower plate 7-3, a spherical hinge 7-4, a spherical hinge connecting column 7-5, an X / Y direction steering engine 7-6, an X axis guide rail fixed plate 7-7, an axis guide rail bearing 7-8, a synchronous pulley 7-9, a synchronous belt 7-10, a Y axis guide rail 7-11, a suspension fixed block 7-12, a Z direction linear steering engine 7-13, a tension sensor 7-14, a universal joint 7-15, a universal joint connecting column 7-16, a synchronous belt fixed sliding block 7-17, a steering engine fixed plate 7-18, a steering engine connecting flange 7-19, an X axis guide rail 7-20, a Y guide rail fixed plate 7-21, and a suspension fixed block moving guide rail 7-22. The centroid following upper plate 7-1 is connected with the centroid following lower plate 7-3 through the upper and lower plate connecting column 7-2, the X / Y direction steering engine 7-6 is connected with the centroid following lower plate 7-3 through the steering engine fixed plate 7-18, and simultaneously connected with the synchronous pulley 7-9 through the steering engine connecting flange 7-19, the synchronous pulley 7-9 is connected with the X axis guide rail 7-20 and the Y axis guide rail 7-11 through tight fitting. The X axis guide rail fixed plate 7-7 and the Y guide rail fixed plate 7-21 are both connected with the centroid following lower plate 7-3, and simultaneously the X axis guide rail fixed plate 7-7 is fixedly connected with the X axis guide rail 7-20 through the axis guide rail bearing 7-8, and the Y guide rail fixed plate 7-21 is fixedly connected with the Y axis guide rail 7-11 through the axis guide rail bearing 7-8. Two synchronous belt fixed sliding blocks 7-17 are arranged in the X and Y directions respectively, the synchronous belt fixed sliding blocks 7-17 in the X and Y directions are respectively driven by the synchronous belts 7-10 to move along the X axis guide rail 7-20 and the Y axis guide rail 7-11, and one end of the suspension fixed block moving guide rail 7-22 is connected with the synchronous belt fixed sliding block 7-17 and the other end is connected with the suspension fixed block 7-12, so that when the synchronous belt fixed sliding block 7-17 moves, the suspension fixed block 7-12 also moves correspondingly. The Z direction linear steering engine 7-13 is fixedly connected with the suspension fixed block 7-12, and the output shaft is connected with the tension sensor 7-14. The centroid following upper plate 7-1 is connected with the space crawling robot 8 through a group of universal joints and three groups of spherical hinges, wherein the two ends of the universal joint connecting column 7-16 are respectively connected with the centroid following upper plate 7-1 and the space crawling robot 8 using the universal joint 7-15, and the two ends of the three spherical hinge connecting columns 7-5 are respectively connected with the centroid following upper plate 7-1 and the space crawling robot 8 using the spherical hinge 7-4. On the one hand, this can make the centroid following module only change in the pitch and tilt directions, and limit the roll degree of freedom around the vertical axis, and on the other hand, it can avoid excessive constraint and cause module motion interference. Figure 5 The origin of the coordinate system is fixed on the upper surface of the tension sensor 7-14, the X axis direction indicates the direction from the origin to the outside along the parallel X axis guide rail 7-20, the Z axis direction indicates the vertical upward direction from the origin, and the Y axis follows the right-hand rule.

[0036] As Figure 6As shown, in order to ensure that the compensation force is equivalent to the internal centroid O' of the space crawling robot 8 in space, four connection points A, B, C, D are arranged on the centroid tracking module upper plate 7-1, and a four pyramid is formed with the suspension rope 5-17 connection point O; according to The full equivalent relationship is set at the corresponding position of the space crawling robot A', B', C', D'; when the space crawling robot 8 does not move, that is, the centroid position does not change relative to the robot body, but the whole robot attitude changes, according to the parallel similar suspension principle, the compensation force f is always equivalent to the internal centroid O'.

[0037] The robot control computer 1 calculates the control amount of each joint rotation of the robot according to the crawling motion trajectory computer, then sends the control motion instruction to the space crawling robot 8 through the wireless communication module 2, controls the space crawling robot 8 to crawl on the target spacecraft according to the specified path; at the same time, the angle information of each leg joint of the space crawling robot 8 is collected, then the robot centroid position is obtained by angle and centroid corresponding relationship solution, then it is sent to the ground test system console 3 through the wireless communication module 2.

[0038] The ground test system console 3 receives the centroid position information sent by the robot control computer 1 through the wireless communication module 2, calculates the motion angle of the three direction motors of the centroid tracking module 7, then sends it to the X / Y direction rudder 7-6 and Z direction linear rudder 7-13 to control the change of the suspension point position of the suspension rope 5-17, so as to change the structure of the parallel suspension in real time, and ensure that the centroid of the robot is always on the extension line of the suspension rope 5-17; at the same time, the ground test system console 3 collects the data of the tension sensor 7-14, the Hall angle sensor 5-19 and the laser displacement sensor 5-10, calculates the position of the suspension point, then the ground test system console 3 sends the corresponding control amount to the X / Z axis gravity compensation control module 5-24 and the Y axis gravity compensation control module 6-4 respectively, then the X / Z axis gravity compensation control module 5-24 controls the X axis gravity compensation servo motor 5-1 and the Z axis rope winding motor module 5-5 to act, and the Y axis gravity compensation control module 6-4 controls the Y axis gravity compensation servo motor 6-1 to act, so as to drive the X / Z axis gravity compensation module to move along the X axis, Y axis and Z axis, at the same time, the Y axis tension compensation spring 5-11 and the Y axis compression compensation spring 5-12 fixed on the rope outlet limiting plate 5-4 move the rope outlet base 5-13 to the balance position under the antagonistic action of tension / pressure, and adjust the tension of the suspension rope 5-17 to the gravity compensation value.

[0039] The control principle is as follows: when the robot four-foot moves, in addition to the posture change of the robot body, the configuration also changes, which causes the position of the center of mass relative to the body to change, at this time, the gravity deflection torque is generated, so that the robot has the risk of overturning. In order to eliminate the risk, the center of mass following module 7 in the space robot ground microgravity crawling test system further comprises an X / Y direction steering wheel 7-6, a Z direction linear steering wheel 7-13, a synchronous pulley 7-9, a synchronous belt 7-10 and the like. When the space crawling robot 8 starts to move, the robot collects the angles of each leg joint in real time and sends them to the robot control computer 1, then the robot control computer 1 obtains the position of the center of mass of the robot through the angle and center of mass corresponding relationship, and then sends it to the ground test system console 3 to obtain the movement angle of the three direction motors of the center of mass tracking module 7, and then sends it to the X / Y direction steering wheel 7-6 and the Z direction linear steering wheel 7-13 to control the change of the hanging point position of the suspension rope 5-17, so as to change the structure of the parallel hanging frame in real time, and ensure that the center of mass of the robot is always on the extension line of the suspension rope 5-17.

[0040] In order to ensure the gravity compensation effect of the space crawling robot 8 in the whole process of the ground microgravity crawling test, when the robot moves, in the X-axis direction: the suspension rope 5-17 will cause the out-rope rotating block 5-21 to rotate, the rotating angle of the out-rope rotating block 5-21 around the Z-axis direction is alpha, at this time, the Hall angle sensor 5-19 fixed on the out-rope moving base 5-13 collects the rotating angle and sends it to the ground test system console 3, the movement value of the X-axis is obtained through the ground test system console 3, and then the X / Z-axis gravity compensation control module 5-24 is sent and controls the X-axis gravity compensation servo motor 5-1 to act, so as to drive the X / Z-axis gravity compensation module to move along the X-axis; in the Y-axis direction, the suspension rope 5-17 will cause the Y-axis out-rope compensation slider 5-15 fixed on the out-rope moving base 5-13 to move on the Y-axis out-rope compensation guide rail 5-16, at this time, the laser displacement sensor 5-10 fixed on the out-rope rear limiting plate 5-4 will collect the movement value of the Y-axis, and then feedback to the ground test system console 3, then the movement amount of the Y-axis gravity compensation module 6 is obtained through the ground test system console 3, and then the control data is sent to the Y-axis gravity compensation control module 6-4 to control the Y-axis gravity compensation servo motor 6-1 to act, so as to drive the X / Z-axis gravity compensation module to move along the Y-axis, and at the same time, the Y-axis tension compensation spring 5-11 and the Y-axis compression compensation spring 5-12 fixed on the out-rope rear limiting plate 5-4 will move the out-rope moving base 5-13 to the balance position under the antagonistic action of tension / pull force; in the Z direction, the tension of the suspension rope 5-17 will change, the change value is obtained through the tension sensor 5-8 and the tension sensor module 7-14 in the center of mass following module 7, then the ground test system console 3 obtains the Z-direction compensation value through the change value, and then sends it to the X / Z-axis gravity compensation control module 5-24 and controls the Z-axis around the rope motor module 5-5 to act to adjust the tension to the gravity compensation value.

[0041] The contents not described in detail in the specification of the present application are the known technology of those skilled in the art.

[0042] Although the present application has been disclosed with the preferred embodiments as above, it is not intended to limit the present application, and any person skilled in the art can make possible changes and modifications to the technical solutions of the present application by using the disclosed methods and technical contents without departing from the spirit and scope of the present application, therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application, which does not depart from the content of the technical solutions of the present application, all belong to the protection scope of the technical solutions of the present application.

Claims

1. A microgravity crawling test system for a space robot, characterized in that, The system includes an outer frame, X / Z axis gravity compensation modules, Y axis gravity compensation modules, a center of mass following module, a target simulator, a robot control computer, a wireless communication module, and a ground test system control console. The lower end of the outer frame is fixed to the ground, and the X / Z axis gravity compensation modules and Y axis gravity compensation modules are installed on the upper end. The center of mass following module is fixed to the suspension rope in the X / Z axis gravity compensation module through a tension sensor, and fixed to the space crawling robot through a universal joint and ball joint. The space crawling robot is placed on the upper end of the target simulator, and placed on the ground through universal wheels at the lower end. The outer frame provides support and transmission capabilities for the entire system; The X / Z axis gravity compensation module and the Y axis gravity compensation module are used together to ensure that the position of the suspension rope always follows the robot in three directions; The center of mass following module is used to passively adapt to changes in robot posture and configuration by adjusting the position of the suspension point so that the suspension always passes through the robot's center of mass; The space crawling robot serves as a suspended target, while simultaneously feeding back its joint angles to the robot control computer; The target simulator is used to provide a passive microgravity simulation environment with three degrees of freedom; The robot control computer calculates the rotation control quantities of each joint of the space crawling robot based on the crawling trajectory, and sends control motion commands to the space crawling robot through the wireless communication module, controlling the space crawling robot to crawl on the target spacecraft along the specified path. At the same time, it collects the angle information of each leg joint of the space crawling robot, and then calculates the position of the robot's center of mass by solving the correspondence between the angle and the center of mass. Then, it sends the information to the ground test system control console through the wireless communication module. The ground test system control console calculates the three-direction motor motion angles of the center of mass tracking module, and then sends them to the center of mass following module to control the position of the suspension point to change accordingly, so as to ensure that the center of mass of the space crawling robot is always on the extension line of the suspension rope of the X / Z axis gravity compensation module.

2. The space robot ground microgravity crawling test system according to claim 1, characterized in that, The outer frame includes a support truss, a Y-axis moving guide rail, a Y-axis moving rack, an X-axis moving support beam, an X-axis moving guide rail, and an X-axis moving rack; the lower end of the support truss is fixed to the ground, and the upper end is equipped with the Y-axis moving guide rail and the Y-axis moving rack in parallel; the lower end of the X-axis moving support beam is fixed to the Y-axis gravity compensation base, and the upper end is equipped with the X-axis moving guide rail and the X-axis moving rack. The Y-axis moving rack meshes with the Y-axis gravity compensation gear, and the Y-axis gravity compensation slider is installed on the Y-axis moving guide rail. The X-axis moving rack meshes with the X-axis gravity compensation gear, and the X-axis gravity compensation slider is installed on the X-axis moving guide rail.

3. The microgravity crawling test system for space robots according to claim 1, characterized in that, The X / Z axis gravity compensation module includes an X-axis gravity compensation servo motor, an X-axis gravity compensation reducer, a first rope-out pulley, a rope-out rear limit plate, a Z-axis rope-winding motor module, a rope-winding wheel, an X / Z axis gravity compensation base, a tension sensor module, an X-axis gravity compensation gear, a laser displacement sensor, a Y-axis tension compensation spring, a Y-axis compression compensation spring, a rope-out moving base, an X-axis gravity compensation slider, a Y-axis rope-out compensation slider, a Y-axis rope-out compensation guide rail, a suspension rope, a rope-out front limit plate, a Hall angle sensor, a second rope-out pulley, a rope-out rotating block, a rope-out limit hole shaft, a rope-out large pulley, and an X / Z axis gravity compensation control module. The upper end of the X-axis gravity compensation reducer is connected to the X-axis gravity compensation servo motor. The lower end of the force compensation reducer, the rope exiting rear limit plate, the Z-axis rope winding motor module, the X-axis gravity compensation slider, the rope exiting compensation guide rail, the rope exiting front limit plate, and the X / Z-axis gravity compensation control module are all fixed on the X / Z-axis gravity compensation base. At the same time, the output shaft of the X-axis gravity compensation reducer is tightly connected to the X-axis gravity compensation gear. One end of the suspension rope is fixed on the winding wheel connected to the Z-axis rope winding motor module, and then along the pulley in the tension sensor module fixed to the rope exiting rear limit plate to the first rope exiting small pulley, then to the rope exiting large pulley fixed to the rope exiting moving base, then through the rope exiting limit hole shaft and the second rope exiting small pulley fixed to the rope exiting rotating block, and finally the other end of the suspension rope is connected to the tension sensor in the center of gravity following module.

4. The space robot ground microgravity crawling test system according to claim 3, characterized in that, The components fixed on the upper surface of the X / Z axis gravity compensation base include the lower end of the X-axis gravity compensation reducer and the rear limit plate for rope output, the Z-axis rope winding motor module, the rope output compensation guide rail, and the X / Z axis gravity compensation control module; the components fixed on the lower surface of the X / Z axis gravity compensation base include the X-axis gravity compensation slider; and the components fixed on the front surface of the X / Z axis gravity compensation base include the front limit plate for rope output.

5. The microgravity crawling test system for space robots according to claim 3, characterized in that, In the Y-axis direction, the suspension rope causes the Y-axis rope output compensation slider, which is fixed to the rope output moving base, to move on the Y-axis rope output compensation guide rail. At this time, the laser displacement sensor fixed to the rope output rear limit plate will collect the value of the Y-axis movement and then feed it back to the ground test system control console. Then, the ground test system control console calculates the movement amount of the Y-axis gravity compensation module and then sends the control data to the Y-axis gravity compensation control module of the Y-axis gravity compensation module to control the Y-axis gravity compensation servo motor of the Y-axis gravity compensation module to actuate, driving the X / Z axis gravity compensation module to move along the Y-axis. At the same time, the Y-axis tension compensation spring and Y-axis compression compensation spring fixed to the rope output rear limit plate move the rope output moving base to the equilibrium position under the antagonistic action of tension / compression.

6. The space robot ground microgravity crawling test system according to claim 3, characterized in that, The ground test system control console collects data from the tension sensor, Hall angle sensor, and laser displacement sensor of the center of mass following module, calculates the location of the suspension point, and then sends the corresponding control quantities to the X / Z axis gravity compensation control module and the Y-axis gravity compensation control module of the Y-axis gravity compensation module. The X / Z axis gravity compensation control module then controls the X-axis gravity compensation servo motor and the Z-axis rope winding motor module to operate, while the Y-axis gravity compensation control module controls the Y-axis gravity compensation servo motor of the Y-axis gravity compensation module to operate, thereby driving the X / Z axis gravity compensation module to move along the X, Y, and Z axes. At the same time, the Y-axis tension compensation spring and the Y-axis compression compensation spring fixed on the rope exit limit plate move the rope exit moving base to the equilibrium position under the antagonistic action of tension and compression, and adjust the tension on the suspension rope to the gravity compensation value.

7. The microgravity crawling test system for space robots according to claim 1, characterized in that, The Y-axis gravity compensation module includes a Y-axis gravity compensation servo motor, a Y-axis gravity compensation reducer, a Y-axis gravity compensation gear, a Y-axis gravity compensation control module, a Y-axis gravity compensation base, and a Y-axis gravity compensation slider; The upper end of the Y-axis gravity compensation reducer is fixedly connected to the Y-axis gravity compensation servo motor, and the lower end of the Y-axis gravity compensation reducer and the Y-axis gravity compensation control module are fixed together on the Y-axis gravity compensation base. At the same time, the Y-axis gravity compensation gear is connected to the output shaft of the Y-axis gravity compensation reducer.

8. The microgravity crawling test system for space robots according to claim 1, characterized in that, The center-of-gravity following module includes a center-of-gravity following upper plate, upper and lower plate connecting columns, a center-of-gravity following lower plate, a ball joint, a ball joint connecting column, X / Y directional servos, an X-axis guide rail fixing plate, a directional guide rail bearing, a synchronous pulley, a synchronous belt, a Y-axis guide rail, a suspension fixing block, a Z-axis linear servo, a tension sensor, a universal joint, a universal joint connecting column, a synchronous belt fixing slider, a servo fixing plate, a servo connecting flange, an X-axis guide rail, a Y-axis guide rail fixing plate, and a suspension fixing block moving guide rail. The center-of-gravity following upper plate is connected to the center-of-gravity following lower plate via the upper and lower plate connecting columns. The X / Y directional servos are connected to the center-of-gravity following lower plate via the servo fixing plate and simultaneously connected to the synchronous pulley via the servo connecting flange. The synchronous pulley is tightly fitted to the X-axis and Y-axis guide rails. Both the X-axis and Y-axis guide rail fixing plates are connected to the center-of-gravity following lower plate. The X-axis guide rail is fixedly connected to the Y-axis guide rail via a bearing. Two synchronous belt fixed sliders are arranged in both the X and Y directions. These sliders move along the X-axis and Y-axis guide rails under the influence of the synchronous belts in the X and Y directions, respectively. Simultaneously, one end of the suspension block moving guide rail is connected to the synchronous belt fixed slider, and the other end is connected to the suspension block. Therefore, when the synchronous belt fixed slider moves, the suspension block also moves accordingly. The Z-direction linear servo is fixedly connected to the suspension block, and its output shaft is connected to a tension sensor. The two ends of the universal joint connecting column are connected to the center-of-gravity following plate and the space crawling robot via universal joints, respectively. The two ends of the three ball joint connecting columns are connected to the center-of-gravity following plate and the space crawling robot via ball joints, respectively.

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