Ground microgravity crawling test system for space robot

Abstract

A space robot ground microgravity crawling test system is characterized in that the lower end of an outer frame is fixed on the ground, the upper end of the outer frame is provided with an X / Z-axis gravity compensation module and a Y-axis gravity compensation module, the upper surface of a centroid following module is fixedly connected with a suspension rope in the X / Z-axis gravity compensation module through a tension sensor, and the lower surface of the centroid following module is fixedly connected with a space crawling robot through a universal joint and a spherical hinge; the space crawling robot conducts a space microgravity crawling test on the target simulator, the target simulator is placed on the ground through universal wheels, and when the robot crawl, the target simulator moves in an X / Y mode and rotates around the Z axis under the counter-acting force, so that three-degree-of-freedom space microgravity simulation conditions are provided. Meanwhile, the X / Z-axis gravity compensation module and the Y-axis gravity compensation module can realize micro-gravity compensation autonomous following of the space crawling robot in the X / Y / Z directions, and the mass center following module can realize that the mass center of the robot is always on a suspension point extension line when the posture and the configuration of the robot are changed.

Description

Technical Field

[0001] The invention relates to a ground microgravity crawling test system for a space robot, and belongs to the field of space microgravity environment simulation tests. Background Art

[0002] Large spacecraft are high-value aerospace equipment for space resource utilization and scientific exploration, and on-orbit services are the key to ensuring their long-term stable operation in orbit. However, typical tasks such as extravehicular sudden fault handling, routine inspection and maintenance, etc., still rely on astronauts' extravehicular activities to complete, which are highly dangerous, poor in real-time performance, and have long cycles. There is an urgent need for the ability to replace astronauts to achieve full-area on-orbit inspections of large spacecraft. In order to reach a large range in a multi-obstacle environment outside the cabin, the development of space crawling robot technology is a necessary way to enhance the on-orbit service and maintenance capabilities of large spacecraft. Its core lies in adapting to the complex structure of the spacecraft, and possessing multi-mode motion planning and control capabilities and low-energy driving capabilities. In order to verify the above key capabilities, it is necessary to develop a ground microgravity crawling test system to provide conditions and guarantees for the ground verification of space robots.

[0003] The scientific document "Design and Implementation of a Ground Test Platform for Space Robots Based on Air Flotation" (Modern Machinery, Vol. 3, No. 1, June 2007) introduced a test platform for realizing ground microgravity simulation tests of space robots using air flotation as a gravity compensation method. However, this platform can only realize gravity-compensated microgravity simulation movements of space robots on a two-dimensional plane. Chinese patent CN113264203B discloses a multi-target six-degree-of-freedom microgravity ground simulation system and a method of use, which consists of a high-rigidity gantry, a discrete guidance system, a six-degree-of-freedom simulation platform, and a motion measurement system. The system uses an external measurement system to obtain the spatial position of the suspended object in the system. However, the surface structure of large spacecraft is complex and there are a large number of blocked areas. External visual measurement is prone to lose the suspended object, so it is impossible to fully simulate the scene of a space robot crawling on the complex surface of a large spacecraft; Chinese patent CN103466109A discloses a ground simulation experimental device for a space microgravity environment, which consists of a foundation, two support columns, a transverse air-floating guide rail, a longitudinal air-floating guide rail, a pulley, and a weightlessness simulation control system. The system uses a single-point suspension fixed point, and the posture and configuration of the space crawling robot will change during the crawling process, resulting in a time-varying center of mass. The use of a fixed-point suspension will cause the space crawling robot to overturn due to the gravity deflection torque, so it does not meet the use requirements. Summary of the invention

[0004] The technical problem to be solved by the present invention is: to overcome the shortcomings of the prior art and provide a ground microgravity crawling test system for a space robot, which has the advantage of autonomously achieving three-dimensional gravity compensation following without the help of external measurement data, and can avoid the risk of overturning caused by changes in the center of mass of the suspended robot.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] A ground microgravity crawling test system for a space robot 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 X / Z-axis gravity compensation module and the Y-axis gravity compensation module are installed on the upper end; the center of mass following module is fixedly connected to the suspension rope in the X / Z-axis gravity compensation module through a tension sensor on the upper end, and is fixedly connected to the space crawling robot through a universal joint and a ball joint on the lower end; the space crawling robot is placed on the upper end of the target simulator, and the lower end is placed on the ground through universal wheels;

[0007] The outer frame is used to provide support and transmission capabilities for the entire system;

[0008] 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;

[0009] The center of mass following module is used to passively adapt to the robot's posture changes and configuration changes to adjust the suspension point position so that the suspension always passes through the robot's center of mass;

[0010] The space crawler robot is used to provide the suspended target and to feed back its own joint angles to the robot control computer;

[0011] The target simulator is used to provide a passive microgravity simulation environment with three degrees of freedom.

[0012] Furthermore, the outer frame includes a supporting truss, a Y-axis movable guide rail, a Y-axis movable rack, an X-axis movable support beam, an X-axis movable guide rail, and an X-axis movable rack; the lower end of the supporting truss is fixed to the ground, and the Y-axis movable guide rail and the Y-axis movable rack are installed in parallel at the upper end; the lower end of the X-axis movable support beam is fixed to the Y-axis gravity compensation base, and the X-axis movable guide rail and the X-axis movable rack are installed on it; wherein the Y-axis movable rack is meshed with the Y-axis gravity compensation gear, the Y-axis gravity compensation slider is installed on the Y-axis movable guide rail, the X-axis movable rack is meshed with the X-axis gravity compensation gear, and the X-axis gravity compensation slider is installed on the X-axis movable guide rail.

[0013] Furthermore, the X / Z-axis gravity compensation module includes an X-axis gravity compensation servo motor, an X-axis gravity compensation reducer, a first rope output small pulley, a rope output rear limit plate, a 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 output mobile base, an X-axis gravity compensation slider, a Y-axis rope output compensation slider, a Y-axis rope output compensation guide rail, a suspension rope, a rope output front limit plate, a Hall angle sensor, a second rope output small pulley, a rope output rotating block, a rope output limit hole shaft, a rope output 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, and the lower end of the X-axis gravity compensation reducer is fixed on the X / Z-axis gravity compensation base together with the rear limit plate after the rope is output, the Z-axis rope winding motor module, the X-axis gravity compensation slider, the rope output compensation guide rail, the rope output front limit plate, and the X / Z-axis gravity compensation control module. At the same time, the output shaft of the X-axis gravity compensation reducer is connected with the X-axis gravity compensation gear in a tight fit; one end of the suspension rope is fixed to the rope winding wheel connected to the rope winding motor module, and then along the pulley in the tension sensor module fixed on the rear limit plate of the rope output to the first rope output small pulley, and then to the rope output large pulley fixed on the rope output moving base, and then through the rope output limit hole shaft and the second rope output small pulley fixed on the rope output rotating block, and finally the other end of the suspension rope is connected to the tension sensor in the center of mass following module.

[0014] Furthermore, 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, 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, and the Y-axis gravity compensation gear is connected to the output shaft of the Y-axis gravity compensation reducer.

[0015] Furthermore, 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 ball joint, a ball joint connecting column, an X / Y direction servo, an X-axis guide rail fixing plate, an axis guide rail bearing, a synchronous pulley, a synchronous belt, a Y-axis guide rail, a suspension fixed block, a Z-direction linear servo, a tension sensor, a universal joint, a universal joint connecting column, a synchronous belt fixed slider, a servo fixing plate, a servo connecting flange, an X-axis guide rail, a Y guide rail fixing plate, and a suspension fixed block moving guide rail. The mass follower upper plate is connected to the mass follower lower plate through the upper and lower plate connecting columns, the X / Y direction servo is connected to the mass follower lower plate through the servo fixing plate, and is connected to the synchronous pulley through the servo connecting flange, and the synchronous pulley is connected to the X-axis guide rail and the Y-axis guide rail through a tight fit; the X-axis guide fixing plate and the Y-guide fixing plate are both connected to the mass follower lower plate, and the X-axis guide fixing plate is fixedly connected to the X-axis guide rail through the shaft guide bearing, and the Y-guide fixing plate is fixedly connected to the Y-axis guide rail through the shaft guide bearing; two synchronous belt fixed sliders are arranged in the X and Y directions, and the synchronous belt fixed sliders in the X and Y directions are respectively arranged in the X and Y directions and are driven by the synchronous belts to move along the X-axis guide rail and the Y-axis guide rail, and the suspension is fixed at the same time. One end of the fixed block moving guide rail is connected to the synchronous belt fixed slider, and the other end is connected to the suspension fixed block. When the synchronous belt fixed slider moves, the suspension fixed block will also be driven to move accordingly; the Z-direction linear servo is fixedly connected to the suspension fixed block, and the output shaft is connected to the tension sensor; the two ends of the universal joint connecting column are respectively connected to the center of mass following upper plate and the space crawling robot using universal joints, and the two ends of the other three ball joint connecting columns are respectively connected to the center of mass following upper plate and the space crawling robot using ball joints. On the one hand, this can make the center of mass following module only change in pitch and tilt direction, while limiting the rolling freedom around the vertical axis. On the other hand, it can avoid excessive constraints and cause module motion interference.

[0016] Furthermore, the space robot ground microgravity crawling test system also includes a robot control computer, a wireless communication module, and a ground test system console;

[0017] The robot control computer calculates the rotation control amount of each joint of the robot according to the crawling motion trajectory, and then sends the 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; at the same time, the angle information of each leg joint of the space crawling robot is collected, and then the robot's center of mass position is obtained by solving the corresponding relationship between the angle and the center of mass, and then sent 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 motor in the three directions of the center of mass tracking module 7, and then sends it to the X / Y direction servo 7-6 and the Z direction linear servo 7-13 to control the corresponding change of the suspension point position of the suspension rope 5-17, so as to change the structure of the parallel hanger in real time to ensure that the center of mass 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, and then the ground test system console 3 respectively controls the corresponding The amount is sent to the X / Z-axis gravity compensation control module 5-24 and the Y-axis gravity compensation control module 6-4, and 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 operate, and the Y-axis gravity compensation control module 6-4 controls the Y-axis gravity compensation servo motor 6-1 to operate, thereby driving 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 rear limit plate 5-4 after the rope is discharged move the rope-discharging mobile base 5-13 to the equilibrium position under the antagonistic action of tension / pressure, and adjust the tension on the suspension rope 5-17 to the gravity compensation value.

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

[0020] (1) The present invention uses the system's internal sensor to obtain the robot's position, and then controls gravity compensation for real-time autonomous following. Compared with the prior art, it reduces the number of external measurement devices, reduces the overall cost of the system, and can also avoid the risk of loss of measurement data due to occlusion and thus loss of control of gravity tracking, while increasing the real-time following frequency.

[0021] (2) The present invention uses a suspension rope to connect the robot through parallel similar hangers. Compared with the fixed suspension in the prior art, it can passively and autonomously achieve the tracking effect of the robot's posture and eliminate the gravity deflection torque caused by the change of the robot's posture during single-rope suspension.

[0022] (3) The present invention adopts a center of mass following module to replace the fixed suspension point in the prior art, which can realize real-time change of the structure of the parallel hanger 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 THE DRAWINGS

[0023] Figure 1 The following is a simplified diagram of the system structure in an embodiment of the present invention.

[0024] Figure 2 Schematic diagram of the inner and outer frame modules in an embodiment of the present invention.

[0025] Figure 3 Schematic diagram of an X / Z-axis gravity compensation module in an embodiment of the present invention.

[0026] Figure 4 Schematic diagram of a Y-axis gravity compensation module in an embodiment of the present invention.

[0027] Figure 5 Schematic diagram of a centroid following module in an embodiment of the present invention.

[0028] Figure 6 Schematic diagram of the force acting on the center of mass following module in an embodiment of the present invention.

[0029] Figure numerals: 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-out rear limit 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-out moving base-5-13, X-axis gravity compensation slider-5-14, Y-axis rope-out compensation slider-5-15, Y-axis rope-out compensation guide rail-5-16, suspension rope-5-17, rope-out front limit plate-5-18, Hall angle sensor- 5-19, second small pulley for rope output-5-20, rope output rotating block-5-21, rope output limit hole shaft-5-22, rope output 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, ball joint-7-4, ball joint connection Column-7-5, X / Y servo-7-6, X-axis guide fixing plate-7-7, shaft guide bearing-7-8, synchronous pulley-7-9, synchronous belt-7-10, Y-axis guide-7-11, suspension fixing block-7-12, Z-direction linear servo-7-13, tension sensor-7-14, universal joint-7-15, universal joint connecting column-7-16, synchronous belt fixing slider-7-17, servo fixing plate-7-18, servo connecting flange-7-19, X-axis guide-7-20, Y guide fixing plate-7-21, suspension fixing block moving guide-7-22. DETAILED DESCRIPTION

[0030] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0031] like Figure 1As shown, a ground microgravity crawling test system for a space robot comprises a robot control computer 1, a wireless communication module 2, a ground test system 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 fixedly connected to the suspension rope 5-17 of the X / Z-axis gravity compensation module 5 through its own tension sensor 7-14, and the lower end is fixedly connected to the suspension rope 5-17 of the X / Z-axis gravity compensation module 5 through the tension sensor 7-14. Universal joint 5-12 and ball joint 5-4 are fixedly connected to space crawling robot 8. Space crawling robot 8 performs space microgravity crawling test on target simulator 9. Target simulator 9 is placed on the ground through universal wheels. When the robot crawls, it will generate reaction force on target simulator 9. Target simulator 9 is not constrained from the ground and will move X / Y and rotate around Z axis under the reaction force. When the friction between the ground and target simulator is ignored, it can be considered that the target simulator has three-degree-of-freedom space microgravity simulation capability in X / Y movement and Z rotation. The definition of three axes can refer to the example Figure 1 For explanation, the origin is fixed at the lower right corner of the frame ground, 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, and the Y-axis follows the right-hand rule.

[0032] like Figure 2 As shown, the outer frame 4 of the present invention includes a supporting truss 4-1, a Y-axis movable guide rail 4-2, a Y-axis movable rack 4-3, an X-axis movable support beam 4-4, an X-axis movable guide rail 4-5, and an X-axis movable rack 4-6; the lower end of the supporting truss 4-1 is fixed to the ground, and the Y-axis movable guide rail 4-2 and the Y-axis movable rack 4-3 are installed in parallel on the upper end; the lower end of the X-axis movable support beam 4-4 is fixed on the Y-axis gravity compensation base 6-5, and the X-axis movable guide rail 4-5, The X-axis moving rack 4-6; wherein the Y-axis moving rack 4-3 is meshed with the Y-axis gravity compensation gear 6-3, the Y-axis gravity compensation slider 6-6 is installed on the Y-axis moving guide rail 4-2, the X-axis moving rack 4-6 is meshed with the X-axis gravity compensation gear 5-9, and the X-axis gravity compensation slider 5-14 is installed on the 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 the gear rack transmission to realize the gravity compensation position adjustment.

[0033] like Figure 3As shown, the X / Z-axis gravity compensation module 5 of the present invention includes an X-axis gravity compensation servo motor 5-1, an X-axis gravity compensation reducer 5-2, a first rope-out small pulley 5-3, a rope-out rear limit plate 5-4, a rope winding motor module 5-5, a rope 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, and a Y-axis compression Compensation spring 5-12, rope-out moving base 5-13, X-axis gravity compensation slider 5-14, Y-axis rope-out compensation slider 5-15, Y-axis rope-out compensation guide rail 5-16, suspension rope 5-17, rope-out front limit plate 5-18, Hall angle sensor 5-19, second rope-out small pulley 5-20, rope-out rotating block 5-21, rope-out limit hole shaft 5-22, rope-out large pulley 5-23, X / Z-axis gravity compensation control module 5-24. The upper end of the X-axis gravity compensation reducer 5-2 is connected to the X-axis gravity compensation servo motor 5-1, and the lower end of the X-axis gravity compensation reducer 5-2 and the rear limit plate 5-4 after the rope is discharged, the Z-axis rope winding motor module 5-5, the X-axis gravity compensation slider 5-14, the rope discharge compensation guide rail 5-16, the rope discharge front limit 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 (the components fixed on the upper surface of the X / Z-axis gravity compensation base 5-7 include the lower end of the X-axis gravity compensation reducer 5-2 and the rear limit plate 5-4 after the rope is discharged, the Z-axis rope winding motor module 5-5, the rope discharge 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 include the X-axis gravity compensation reducer 5-2 and the rear limit plate 5-4 after the rope is discharged, the Z-axis rope winding motor module 5-5, the rope discharge compensation guide rail 5-16, and the X / Z-axis gravity compensation control module 5-24 Compensation slider 5-14; the components fixed on the front surface of the X / Z-axis gravity compensation base 5-7 include the front limit plate 5-18 for rope output, and at the same time, the output shaft of the X-axis gravity compensation reducer 5-2 is tightly fitted and connected to the X-axis gravity compensation gear 5-9; one end of the suspension rope 5-17 is fixed on the rope winding wheel 5-6 connected to the rope winding motor module 5-5, and then along the pulley in the tension sensor module 5-8 fixed on the rear limit plate 5-4 for rope output to the first small rope output pulley 5-3, and then to the large rope output pulley 5-23 fixed on the rope output moving base 5-13, and then through the rope output limit hole shaft 5-22 and the second small rope output pulley 5-20 fixed on the rope output rotating block 5-21, and finally the other end of the suspension rope 5-17 is connected to 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 rope-out compensation slider 5-15 fixedly connected to the rope-out mobile base 5-13 to move on the Y-axis rope-out compensation guide rail 5-16. At this time, the laser displacement sensor 5-10 fixed on the rear limit plate 5-4 after rope out will collect the value of Y-axis movement, and then feed it back to the ground test system console 3. Then the ground test system console 3 calculates the movement 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 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 rear limit plate 5-4 after rope out move the rope-out mobile base 5-13 to a balanced position under the antagonistic action of tension / pressure.

[0034] like Figure 4 As shown, the Y-axis gravity compensation module 6 of the present invention 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 fixedly connected to the Y-axis gravity compensation servo motor 6-1, and the lower end is fixed together with the Y-axis gravity compensation control module 6-4 on the Y-axis gravity compensation base 6-5, and the Y-axis gravity compensation gear 6-3 is connected to the output shaft of the Y-axis gravity compensation reducer 6-2.

[0035] like Figure 5As shown, the center of mass following module 7 of the present invention includes a center of mass following upper plate 7-1, an upper and lower plate connecting column 7-2, a center of mass following lower plate 7-3, a ball joint 7-4, a ball joint connecting column 7-5, an X / Y direction servo 7-6, an X-axis guide rail fixing 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 servo 7-13, a tension sensor 7-14, a universal joint 7-15, a universal joint connecting column 7-16, a synchronous belt fixed slider 7-17, a servo fixing plate 7-18, a servo connecting flange 7-19, an X-axis guide rail 7-20, a Y-guide rail fixing plate 7-21, and a suspension fixed block moving guide rail 7-22. The mass follower upper plate 7-1 is connected to the mass follower lower plate 7-3 through the upper and lower plate connecting column 7-2, the X / Y direction servo 7-6 is connected to the mass follower lower plate 7-3 through the servo fixing plate 7-18, and is connected to the synchronous pulley 7-9 through the servo connecting flange 7-19, and the synchronous pulley 7-9 is connected to the X-axis guide rail 7-20 and the Y-axis guide rail 7-11 by tight fit; the X-axis guide rail fixing plate 7-7 and the Y-guide rail fixing plate 7-21 are both connected to the mass follower lower plate 7-3 At the same time, the X-axis guide rail fixing plate 7-7 is fixedly connected to the X-axis guide rail 7-20 through the shaft guide rail bearing 7-8, and the Y-axis guide rail fixing plate 7-21 is fixedly connected to the Y-axis guide rail 7-11 through the shaft guide rail bearing 7-8; two synchronous belt fixed sliders 7-17 are arranged in the X and Y directions, and the synchronous belt fixed sliders 7-17 in the X and Y directions are respectively driven by the synchronous belts 7-10 arranged in the X and Y directions to move along the X-axis guide rail 7-20 and the Y-axis guide rail 7-11, and at the same time, the suspension is fixed One end of the fixed block moving guide rail 7-22 is connected to the synchronous belt fixed slider 7-17, and the other end is connected to the suspension fixed block 7-12. When the synchronous belt fixed slider 7-17 moves, the suspension fixed block 7-12 will also move accordingly; the Z-direction linear servo 7-13 is fixedly connected to the suspension fixed block 7-12, and the output shaft is connected to the tension sensor 7-14; the center of mass following upper plate 7-1 and the space crawling robot 8 are connected through a set of universal joints and three sets of ball joints, wherein the two ends of the universal joint connecting column 7-16 are respectively connected to the center of mass following upper plate 7-1 and the space crawling robot 8 by universal joints 7-15, and the two ends of the three ball joint connecting columns 7-5 are respectively connected to the center of mass following upper plate 7-1 and the space crawling robot 8 by ball joints 7-4. On the one hand, this can make the center of mass following module only change in pitch and tilt direction, and limit the rolling freedom around the vertical axis. On the other hand, it can avoid excessive constraints and module motion interference. Figure 5 The origin of the central coordinate system is fixed at the center of the upper surface of the tension sensor 7-14, the X-axis direction indicates that it points outward from the origin along the parallel X-axis guide 7-20, the Z-axis direction indicates that it points vertically upward along the rope from the origin, and the Y-axis follows the right-hand rule.

[0036] like Figure 6As shown, in order to ensure that the compensation force acts equivalently on the internal mass center O' of the space crawling robot 8 in space, four connection points A, B, C, and D are set on the upper plate 7-1 of the mass center following module to form a tetrahedron with the connection point O of the suspension rope 5-17; according to The congruence relationship sets connection points A', B', C', and D' at corresponding positions of the space crawling robot; when the space crawling robot 8 does not move, that is, the position of the center of mass does not change relative to the robot body, but the posture of the entire robot pitches and tilts, according to the principle of parallel similar hangers, it can be seen that the compensation force f always acts equivalently on the internal center of mass O'.

[0037] The robot control computer 1 calculates the rotation control amount of each joint of the robot according to the crawling motion trajectory, and then sends a control motion instruction to the space crawling robot 8 through the wireless communication module 2 to control 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, and then the robot's center of mass position is obtained by solving the corresponding relationship between the angle and the center of mass, and then sent to the ground test system console 3 through the wireless communication module 2.

[0038] 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 motor in the three directions of the center of mass tracking module 7, and then sends it to the X / Y direction servo 7-6 and the Z direction linear servo 7-13 to control the corresponding change of the suspension point position of the suspension rope 5-17, so as to change the structure of the parallel hanger in real time to ensure that the center of mass 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, and then the ground test system console 3 respectively controls the corresponding The amount is sent to the X / Z-axis gravity compensation control module 5-24 and the Y-axis gravity compensation control module 6-4, and 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 operate, and the Y-axis gravity compensation control module 6-4 controls the Y-axis gravity compensation servo motor 6-1 to operate, thereby driving 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 rear limit plate 5-4 after the rope is discharged move the rope-discharging mobile base 5-13 to the equilibrium position under the antagonistic action of tension / pressure, and adjust the tension on the suspension rope 5-17 to the gravity compensation value.

[0039] That is, the control principle is as follows: when the robot's quadruped moves, in addition to the posture change of the robot body, its configuration also changes, which causes the position of its center of mass relative to the body to change accordingly, and at this time, a gravity deflection torque is generated, which makes the robot capsize. In order to eliminate this risk, the center of mass following module 7 in the ground microgravity crawling test system of a space robot of the present invention also includes an X / Y direction servo 7-6, a Z direction linear servo 7-13, a synchronous pulley 7-9, a synchronous belt 7-10, etc. When the space crawling robot 8 starts crawling, the robot collects the angles of its leg joints in real time and sends them to the robot control computer 1, which then calculates the robot's center of mass position through the corresponding relationship between the angle and the center of mass, and then sends it to the ground test system console 3, which calculates the three-direction motor movement angles of the center of mass tracking module 7, and then sends them to the X / Y servo 7-6 and the Z-direction linear servo 7-13 to control the corresponding changes in the suspension point position of the suspension rope 5-17, so as to change the structure of the parallel hanger in real time to ensure that the robot's center of mass is always on the extension line of the suspension rope 5-17.

[0040] At the same time, in order to ensure the gravity compensation effect of the crawling robot 8 in the ground microgravity crawling test space throughout the whole process, when the robot moves, in the X-axis direction: the suspension rope 5-17 will cause the rope-out rotating block 5-21 to rotate, and the rotation angle of the rope-out rotating block 5-21 around the Z-axis direction is α. At this time, the Hall angle sensor 5-19 fixed on the rope-out moving base 5-13 collects the rotation angle and sends it to the ground test system console 3. The ground test system console 3 calculates the movement value of the X-axis, and then sends it to the X / Z-axis gravity compensation control module 5-24 and controls the X-axis gravity compensation servo motor 5-1 to actuate, driving 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 rope-out compensation slider 5-15 fixed to the rope-out moving base 5-13 to move on the Y-axis rope-out compensation guide rail 5-16. At this time, the laser displacement sensor 5-10 fixed on the rope-out rear limit plate 5-4 will collect the Y-axis movement The value is then fed back to the ground test system console 3, and then the ground test system console 3 calculates the movement 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 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 rear limit plate 5-4 after the rope is discharged move the rope-discharging mobile base 5-13 to the equilibrium position under the antagonistic action of tension / pressure; in the Z direction, the tension on the suspension rope 5-17 will change, and its change value is obtained through the tension sensor 7-14 and the tension sensor module 5-8 in the center of mass following module 7, and then the ground test system console 3 obtains the Z-direction compensation value by calculating the change value, and then sends it to the X / Z-axis gravity compensation control module 5-24 and controls the Z-axis winding motor module 5-5 to operate to adjust the tension to the gravity compensation value.

[0041] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

[0042] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A space robot ground microgravity crawling test system, characterized in that: It includes an outer frame, an X / Z-axis gravity compensation module, a Y-axis gravity compensation module, a center of mass following module, a target simulator, a robot control computer, a wireless communication module, and a ground test system console; the lower end of the outer frame is fixed on the ground, and the X / Z-axis gravity compensation module and the Y-axis gravity compensation module are installed on the upper end; the center of mass following module is connected to the suspension rope in the X / Z-axis gravity compensation module through a tension sensor on the upper side, and is connected to the space crawling robot through a universal joint and a ball joint on the lower side; the space crawling robot is placed on the upper side of the target simulator, and the lower end is placed on the ground through universal wheels; The outer frame is used to provide 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 the robot's posture changes and configuration changes to adjust the suspension point position so that the suspension always passes through the robot's center of mass; The space crawler robot acts as a suspended target and simultaneously feeds back its own 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 amount of each joint of the space crawling robot according to the crawling motion trajectory, sends control motion instructions to the space crawling robot through the wireless communication module, and controls the space crawling robot 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 is collected, and then the robot's center of mass position is obtained by solving the corresponding relationship between the angle and the center of mass, and then sent to the ground test system console through the wireless communication module; the ground test system console solves the motor movement angles in three directions of the center of mass tracking module, and then sends them to the center of mass following module to control the corresponding changes in the suspension point position, 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 is characterized in that: The outer frame includes a supporting 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 supporting truss is fixed on the ground, and the Y-axis moving guide rail and the Y-axis moving rack are installed in parallel on the upper end; the lower end of the X-axis moving support beam is fixed on the Y-axis gravity compensation base, and the X-axis moving guide rail and the X-axis moving rack are installed on it; The Y-axis moving rack is meshed with the Y-axis gravity compensation gear, the Y-axis gravity compensation slider is installed on the Y-axis moving guide rail, the X-axis moving rack is meshed 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 space robot ground microgravity crawling test system 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 small pulley, a rope-out rear limit plate, a 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 mobile 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 small 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, and the X-axis gravity compensation servo motor is connected to the X-axis gravity compensation servo motor. The lower end of the force compensation reducer and the rear limit plate after the rope is output, the Z-axis rope winding motor module, the X-axis gravity compensation slider, the rope output compensation guide rail, the front limit plate before the rope is output, and the X / Z-axis gravity compensation control module are fixed on the X / Z-axis gravity compensation base. At the same time, the output shaft of the X-axis gravity compensation reducer is connected with the X-axis gravity compensation gear in a tight fit; one end of the suspension rope is fixed on the rope winding wheel connected to the rope winding motor module, and then along the pulley in the tension sensor module fixed on the rear limit plate after the rope is output to the first rope output small pulley, and then to the rope output large pulley fixed on the rope output moving base, and then through the rope output limit hole shaft and the second rope output small pulley fixed on the rope output rotating block, and finally the other end of the suspension rope is connected to the tension sensor in the center of mass following module.

4. The space robot ground microgravity crawling test system according to claim 3 is 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 after 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; the components fixed on the front surface of the X / Z-axis gravity compensation base include the front limit plate after rope output.

5. The space robot ground microgravity crawling test system according to claim 3 is characterized in that: In the Y-axis direction, the suspension rope will cause the Y-axis rope compensation slider fixed to the rope-out moving base to move on the Y-axis rope-out compensation guide rail. At this time, the laser displacement sensor fixed on the limit plate after rope out will collect the value of Y-axis movement, and then feed it back to the ground test system console. Then the ground test system console calculates the movement 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, 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 the Y-axis compression compensation spring fixed on the limit plate after rope out move the rope-out moving base to a balanced position under the antagonistic action of tension / pressure.

6. The space robot ground microgravity crawling test system according to claim 3, characterized in that: The ground test system console collects data from the tension sensor, Hall angle sensor, and laser displacement sensor of the center of mass following module, and calculates the position of the suspension point. Then the ground test system console sends the corresponding control quantity to the X / Z-axis gravity compensation control module and the Y-axis gravity compensation control module of the Y-axis gravity compensation module. Then the X / Z-axis gravity compensation control module controls the X-axis gravity compensation servo motor and the Z-axis rope winding motor module to actuate, and the Y-axis gravity compensation control module controls the Y-axis gravity compensation servo motor of the Y-axis gravity compensation module to actuate, thereby driving 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 and the Y-axis compression compensation spring fixed on the limit plate after the rope is discharged move the rope-discharging mobile base to the equilibrium position under the antagonistic action of tension / pressure, and adjust the tension on the suspension rope to the gravity compensation value.

7. The space robot ground microgravity crawling test system 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, 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, and the Y-axis gravity compensation gear is connected to the output shaft of the Y-axis gravity compensation reducer.

8. The space robot ground microgravity crawling test system according to claim 1, characterized in that: The mass following module includes a mass following upper plate, an upper and lower plate connecting column, a mass following lower plate, a ball joint, a ball joint connecting column, an X / Y servo, an X-axis guide fixing plate, an axis guide bearing, a synchronous pulley, a synchronous belt, a Y-axis guide, a suspension fixing block, a Z-direction 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, a Y-guide fixing plate, and a suspension fixing block moving guide; the mass following upper plate is connected to the mass following lower plate through the upper and lower plate connecting column, the X / Y servo is connected to the mass following lower plate through the servo fixing plate, and is connected to the synchronous pulley through the servo connecting flange, and the synchronous pulley is connected to the X-axis guide and the Y-axis guide through a tight fit; the X-axis guide fixing plate and the Y-guide fixing plate are both connected to the mass following lower plate, and the X-axis guide fixing plate It is fixedly connected to the X-axis guide rail through the shaft guide rail bearing, and the Y-axis guide rail fixing plate is fixedly connected to the Y-axis guide rail through the shaft guide rail bearing; two synchronous belt fixed sliders are arranged in the X and Y directions respectively, and the synchronous belt fixed sliders in the X and Y directions are respectively arranged and moved along the X-axis guide rail and the Y-axis guide rail under the drive of the synchronous belts in the X and Y directions. At the same time, one end of the suspension fixed block moving guide rail is connected to the synchronous belt fixed slider, and the other end is connected to the suspension fixed block. When the synchronous belt fixed slider moves, it will drive the suspension fixed block to move accordingly; the Z-direction linear servo is fixedly connected to the suspension fixed block, and the output shaft is connected to the tension sensor; the two ends of the universal joint connecting column are respectively connected to the center of mass following upper plate and the space crawling robot using universal joints, and the two ends of the three ball joint connecting columns are respectively connected to the center of mass following upper plate and the space crawling robot using ball joints.

Images