An agilely expandable spacecraft equipment grasping device

Abstract

The present invention relates to a grasping device for spacecraft equipment that can be agilely expanded, which includes: an adapter, a guide pin, a return wire rope, a positioning pin sleeve, a wire reel, a wire reel shaft, a synchronous pulley, a synchronous belt, a return spring device, a reversible ratchet device, a main load-bearing vertical plate, and a bottom plate; the grasping device for spacecraft equipment that can be agilely expanded can effectively solve the assembly problems such as grasping, clamping, transferring, and positioning of equipment during the robotic arm-assisted assembly of large spacecraft equipment, improve the safety, reliability, and assembly efficiency of large spacecraft equipment assembly, and at the same time reduce the labor intensity of workers.

Description

Technical Field

[0001] The present invention belongs to the technical field of end effectors of robotic arms. Specifically, the present invention relates to an end effector that is connected to the end flange of a robotic arm and is used for quickly clamping large-scale spacecraft equipment to form a reliable connection. The reaction force formed by the tensile force of a clockwork spring is transmitted to the end sensor of the robotic arm to sense the end drive. A guide pin is used for precise docking between the end and the equipment. After docking, the pulling force is locked by a reversible ratchet mechanism, and the equipment to be grasped is reliably locked and connected to the end effector, realizing the safe and efficient assembly of large-scale spacecraft equipment. Background Art

[0002] With the development trend of spacecraft product function integration, equipment enlargement, and layout compactness, robotic arms are increasingly used in the process of spacecraft assembly. The demand for the robotic arm to safely, quickly, and accurately drive the end effector to grasp equipment has become extremely urgent. Due to the design concepts of different suppliers and other design constraints of the equipment on the spacecraft, the parts where the equipment can be clamped are different. A new end structure is required to adapt to different working conditions, improve the versatility, efficiency, and flexible adaptability of the end effector, and reduce the production cost of tooling, thus the design of this set of end effectors is proposed. Summary of the Invention

[0003] The purpose of the present invention is to provide a force-sensing end effector for the assembly of large-scale spacecraft equipment that can be quickly expanded. This end effector can effectively solve the assembly problems such as grasping, clamping, transferring, and positioning of equipment during the mechanical arm-assisted assembly of large-scale spacecraft equipment, improve the safety and reliability of the assembly of large-scale spacecraft equipment, improve the assembly efficiency, and at the same time reduce the labor intensity of workers.

[0004] The present invention provides a quickly expandable grasping device for spacecraft equipment, which includes an adapter, a guide pin, a return wire rope, a positioning pin sleeve, a wire rope reel, a wire rope reel shaft, a synchronous pulley, a synchronous belt, a return spring device, a reversible ratchet device, a main load-bearing vertical plate, and a bottom plate. One end of the adapter is coupled with the guide pin, and the other end is used to fix the equipment to be installed. One end of the return wire rope is fixed on the guide pin, passes through the positioning pin sleeve, and is wound and stored in the wire rope reel. The positioning pin sleeve is loaded on the main load-bearing vertical plate and can slide on the main load-bearing vertical plate. The wire rope reel is fixed on the main load-bearing vertical plate through the wire rope reel shaft. The part of it inside the main load-bearing vertical plate is used for winding and storing the return wire rope, and the part outside the main load-bearing vertical plate is linked with the synchronous pulley through the synchronous belt. The synchronous pulley is also fixed on the main load-bearing vertical plate. The return spring device and the reversible ratchet device are integrated on the same axis with the synchronous pulley. The return spring device is used for energy storage, and the reversible ratchet device is used to control the state of the return wire rope.

[0005] Preferably, a wire guiding wheel is also built in the positioning pin sleeve.

[0006] Preferably, the reversible ratchet device includes a power and a stop shaft, a ratchet, a counterclockwise stop clip, a clockwise stop clip, a clip spring, and a ratchet housing; when the ratchet is rotated clockwise, the return wire rope is in an extendable state, and when the ratchet is rotated counterclockwise, the return wire rope is in a state where the elastic force can be recovered.

[0007] Preferably, two reversible ratchet devices are used in one transmission unit. In order to reduce the commutation operation, the two ratchets are commutated simultaneously through a crank-rocker mechanism.

[0008] Preferably, the crank-rocker mechanism includes a cam spring, a cam sliding shaft, a swing rod, and a ratchet commutation knob. The commutation of the reversible ratchet device can be realized by rotating the ratchet commutation knob.

[0009] Preferably, the agilely expandable spacecraft equipment grasping device further includes a six-axis force / torque sensor, a flexible control unit, and a robotic arm. The six-axis force / torque sensor is arranged between the end flange of the grasping device and the robotic arm. After eliminating the influence of the load gravity through a gravity compensation algorithm, it senses the external force acting on the load and conducts position guidance and precise docking through the return wire rope.

[0010] Preferably, after docking, the reversible ratchet device is used to lock the position of the tightened return wire rope to ensure reliable grasping of the equipment.

[0011] Preferably, the agilely expandable spacecraft equipment grasping device further includes an expandable part, which can be used for different installation interfaces and installation positions of the equipment to be grasped or for simultaneous installation of multiple devices.

[0012] The present invention also provides a method for installing the agilely expandable spacecraft equipment grasping device, including the following steps:

[0013] 1) Drive the robotic arm to align the grasping device parallel to the equipment installation end face. Initialize the force state of the grasping device when the end is not subject to external force through the six-axis force / torque sensor, and set it to the zero initial state, that is, the relative force in each direction at the end is 0 N, and the torque in each direction is 0 N·m;

[0014] 2) Turn the ratchet switch to the extended state, stretch the return wire rope, reliably screw the connection point at the end of the return wire rope to the equipment adapter, then turn the ratchet switch to the retracted state, and the clockwork spring drives the retractable wire winding mechanism to form a reverse pulling force for pulling the return wire rope, which is transmitted to the sensor at the end of the robotic arm and the six-axis force / torque sensor installed at the end of the robotic arm for end perception;

[0015] 3) Start the robotic arm control system. The end of the robotic arm drive will sense the direction and magnitude of the external force / moment through the control system and move in the same direction as the external force / moment until the external force is lower than 30 N and the external moment is lower than 4 N·m, at which point the movement stops, ensuring that the end effector can complete a compliant docking with the device without the need for observation.

[0016] 4) Use the return force of the return force wire rope to precisely dock the end device and the guide pin. The guide pin ensures that after the docking at each point is completed, due to the one-way recovery characteristic of the ratchet, the return force wire rope is unidirectionally tightened with the device to be installed, that is, the device is reliably grasped.

[0017] 5) After the device to be grasped is installed, turn the ratchet switch to the extended state, drive the robotic arm to stretch the grasping device away from the device to be installed to a safe position. After disconnecting the connection between the return force wire rope and the device, remove the adapter installed on the device.

[0018] The characteristics of a spacecraft equipment grasping device with agile expandability according to the present invention are as follows:

[0019] 1) Through the force / torque sensor, a "sensing" mechanism is added to the robotic arm. After eliminating the influence of the load gravity through the gravity compensation algorithm, the elastic force of the released return spring is then utilized, and the return spring carried by itself pulls the return force wire rope to roll back and precisely dock the end effector with the adapter installed on the device. Then, the ratchet device is used to lock the return force wire rope traction mechanism to ensure a reliable connection between the device and the end effector, improving the safety and reliability of the assembly process.

[0020] 2) The power provided by the device is the energy stored in the return spring after manual stretching, without the need for an additional power device.

[0021] 3) By different combination methods, it can be expanded to connect and install two devices simultaneously.

[0022] 4) By combining different angles of the expansion part, it can be applicable to different device interface positions and installation environments.

[0023] 5) By means of oblong holes, threaded adjustment supports, etc., it is ensured that the interface position can be steplessly adjusted both horizontally and vertically within a certain range, and the interface has strong adaptability.

[0024] 6) Through the combined positioning of the thick guide of the return force wire rope, the cooperation between the guide pin and the pin hole, the grasping difficulty of the device to be installed is reduced, and the positioning accuracy is improved.

[0025] The present invention has the characteristics of simple operation, strong interface adaptability, no need for an external power source for the device, low labor intensity, high assembly efficiency, accurate and reliable clamping and positioning, and the ability to perform continuous dimensional matching in both horizontal and vertical directions for the flat interface of the installation object. The related technologies have been verified through actual working conditions. Brief Description of the Drawings

[0026] Figure 1 It is a schematic structural diagram of a grasping device for spacecraft equipment that can be rapidly expanded; in the figure: 1 - adapter, 2 - guide pin, 3 - return wire rope, 4 - locating pin sleeve, 5 - wire reel, 6 - synchronous pulley, 7 - synchronous belt, 8 - return spring device, 9 - reversible ratchet device, 10 - main load-bearing vertical plate.

[0027] Fig. 2A is an exploded view of the grasping state of the grasping device for spacecraft equipment that can be rapidly expanded, and Fig. 2B is a schematic diagram of the mechanical transmission of a single column; it can be connected to two sets of vertical equipment interfaces. For equipment with four grasping interfaces, a double-column mode with a double transmission system structure can be used to grasp four points, where 11 - wire guide pulley, 12 - wire reel shaft;

[0028] Fig. 3A is a schematic diagram of the transmission of the grasping device for spacecraft equipment that can be rapidly expanded, and Fig. 3B is a schematic diagram of the reversible ratchet device, where 13 - power and stop shaft, 14 - ratchet, 15 - counterclockwise stop clip, 16 - clockwise stop clip, 17 - clip spring, 18 - cam spring, 19 - cam sliding shaft, 20 - swing rod, 21 - ratchet reversing knob, 22 - ratchet housing; one transmission unit uses two reversible ratchet devices 9. In order to reduce the reversing operation, the two ratchets are reversed simultaneously through a crank-rocker mechanism.

[0029] Figure 4 It is a schematic diagram of the state of the lateral adjustment of the distance between the support columns and the state of simultaneous installation of two devices in the grasping device for spacecraft equipment that can be rapidly expanded. Among them, corresponding to the lateral and longitudinal movement of the transfer position, where 23 - extended load-bearing vertical plate, 24 - bottom plate, 25 - intermediate adjustment support rod, 26 - end adapter of the robotic arm.

[0030] Figure 5 It is a schematic diagram of the usage state of the forklift type (right-angle use of the extended part) in the grasping device for spacecraft equipment that can be rapidly expanded, where 27 - six-axis force / torque sensor, 28 - robotic arm, 29 - flexible control unit.

[0031] Figure 6 It is a schematic diagram of the usage state of a single device (folding use of the extended part) in the grasping device for spacecraft equipment that can be rapidly expanded. Detailed Description of the Preferred Embodiments

[0032] The present invention will be further described in detail below with reference to the accompanying drawings, but this is only exemplary and is not intended to limit the protection scope of the present invention in any way.

[0033] As Figure 1 shown, Figure 1The figure shows a schematic diagram of the structure of a spacecraft equipment grabbing device that can be quickly expanded according to an embodiment of the present invention. Figure 1 It can be seen that the agile end effector for the end flange of the robot arm of the present invention includes an adapter 1, a guide pin 2, a return wire rope 3, a positioning pin sleeve 4, a wire drum 5, a synchronous pulley 6, a synchronous belt 7, a return spring device 8, a reversible ratchet device 9, and a main load-bearing vertical plate 10. Its components also include the wire guide wheel 11 and the wire drum shaft 12 in Figure 2A, and the reversible ratchet device 9 in Figure 2B. Figure 4 The expansion load-bearing vertical plate 23, the bottom plate 24, the middle adjustment support rod 25, and the end adapter 26 of the robot arm, Figure 5 The six-dimensional force / torque sensor 27, the flexible control unit 29 and the robotic arm 28.

[0034] See also Figure 5 The six-dimensional force / torque sensor 27 is installed on the flange of the end effector of the robot arm. The six-dimensional force / torque sensor 27 is installed on the base through the end adapter 26 of the robot arm and the main load-bearing vertical plate 10 and the extended load-bearing vertical plate 23. The layout of the positioning pin sleeve interface is adjusted according to the interface size of the equipment. The height direction installation distance H1~H2, H3~H4 and D1~D2 are adjusted through the oblong holes. The horizontal distance W1~W2 is adjusted through the oblong holes of the bottom plate to realize the horizontal distance adjustment between the supporting columns. The position of the positioning pin sleeve is determined to be in line with the interface size of the equipment by external measurement using a steel ruler, so that the end effector can clamp the height and width direction positions of different interface adapters of the installed equipment.

[0035] See also Figure 1 2A, 2B, 3A and 3B show a schematic diagram of the grasping state of a grasping device for a spacecraft device that can be flexibly expanded according to an embodiment of the present invention; specifically, after adjusting the horizontal width and height accordingly according to the theory, the manipulator arm is operated to drive the grasping device to the approximately aligned position of the device, and the manipulator arm flexible follow-up control device is used to release the grasping device to a zero-gravity state. At this time, the device will move in the direction of the force driven by any external force. At this time, the program is temporarily closed, the device will no longer follow, and the device will be retracted. The head of the return wire rope inserted into the pin groove is pulled out, and the screw connected to the guide pin 2 at the front end is screwed into the adapter 1 installed on the connecting hole of the equipment tooling. After the connection is complete, the control program is started, and the robot arm can move forward along the direction of the return wire rope according to the direction of the force. The return device of the return wire rope generates a pulling force that will eventually make the guide pin and the positioning pin sleeve 4 fit tightly together. At this time, the ratchet knob of the grasping device is suspended to the retracted state, and the return wire rope cannot be pulled out. At this time, the equipment and the grasping device are in a locked state, realizing the equipment alignment and grasping.

[0036] See also Figure 4 、 Figure 5 、Figure 6 This device will provide three different working states through connection methods different from the expansion part, so as to be applicable to different device installation interfaces and installation positions.

[0037] This specific embodiment is only an interpretation of the present invention, and it is not a limitation of the present invention. After reading this specification, those skilled in the art can make modifications to this embodiment without creative contributions according to needs, but as long as it is within the scope of the claims of the present invention, it is protected by the patent law.

Claims

1. An agilely expandable spacecraft equipment grasping device, comprising: Transfer adapter, guide pin, return wire rope, positioning pin sleeve, wire reel, wire reel shaft, synchronous pulley, synchronous belt, return spring device, reversible ratchet device, main load-bearing vertical plate and bottom plate. One end of the transfer adapter is coupled with the guide pin, and the other end is used to fix the device to be installed. One end of the return wire rope is fixed on the guide pin, passes through the positioning pin sleeve, and is wound and stored in the wire reel. The positioning pin sleeve is loaded on the main load-bearing vertical plate and can slide on the main load-bearing vertical plate. The wire reel is fixed on the main load-bearing vertical plate through the wire reel shaft. The part of it inside the main load-bearing vertical plate is used to wind and store the return wire rope, and the part outside the main load-bearing vertical plate is linked with the synchronous pulley through the synchronous belt. The synchronous pulley is also fixed on the main load-bearing vertical plate. The return spring device and the reversible ratchet device are integrated on the same axis. The return spring device is used for energy storage, and the reversible ratchet device is used to control the state of the return wire rope. The reversible ratchet device includes a power and stop shaft, a ratchet, a counterclockwise stop clip, a clockwise stop clip, a clip spring and a ratchet housing; When the ratchet is rotated clockwise, the return wire rope is in an extendable state. When the ratchet is rotated counterclockwise, the return wire rope is in a state where the elastic force can be recovered.

2. The agilely expandable spacecraft equipment grasping device according to claim 1, characterized in that, The positioning pin sleeve also internally has a wire guide wheel.

3. The agilely expandable spacecraft equipment grasping device according to claim 1, characterized in that, It also includes a crank-rocker mechanism, which includes a cam spring, a cam slide shaft, a swing rod and a ratchet reversing knob. The reversal of the reversible ratchet device can be achieved by rotating the ratchet reversing knob.

4. The grab device for spacecraft equipment capable of agile expansion according to claim 1, characterized in that, It also includes a six-axis force / torque sensor, a flexible control unit and a robotic arm. The six-axis force / torque sensor is arranged between the end flange of the grasping device and the robotic arm. After eliminating the influence of the load gravity through the gravity compensation algorithm, it senses the external force acting on the load and conducts position guidance and precise docking through the return wire rope.

5. The grab device for spacecraft equipment with agile expandability according to claim 4, characterized in that, After docking, the reversible ratchet device is used to lock the position of the tightened return wire rope to ensure reliable grasping of the device.

6. The grab device for spacecraft equipment capable of agile expansion according to claim 1, characterized in that, It also includes an expandable part, which can be used for different installation interfaces and installation positions of the device to be grasped or for simultaneous installation of multiple devices.

7. A method for installing a device of an agilely expandable spacecraft device grasping device according to claim 4, comprising the following steps: 1) Drive the robotic arm to align the grasping device parallel to the equipment installation end face. Initialize the force state of the grasping device when the end is not subject to external force through the six-axis force / torque sensor, and set it to the zero initial state, that is, the relative force in each direction at the end is 0 N, and the torque in each direction is 0 N·m; 2) Turn the ratchet switch to the extend state, stretch the return wire rope, reliably screw the connection point at the end of the return wire rope to the equipment adapter, and then turn the ratchet switch to the recovery state. The return spring device drives the recoverable wire reel to form a pulling reaction force for the return wire rope, which is transmitted to the end sensor of the robotic arm and the six-axis force / torque sensor installed at the end of the robotic arm for end perception; 3) Start the robotic arm control system. The end of the robotic arm drive will, through the control system, sense the direction and magnitude of the external force / moment, and at the same time move in the same direction as the external force / moment until the external force is lower than 30 N and the external moment is lower than 4 N·m, then stop moving, ensuring that the entire grasping device can complete a compliant docking with the equipment without the need for observation; 4) Use the return force of the return force wire rope to precisely dock the grasping device with the guide pin. The guide pin ensures that after the docking of each point is completed, due to the one-way recovery characteristic of the ratchet, the return force wire rope is unidirectionally tightened with the equipment to be installed, that is, the equipment is reliably grasped; 5) After the equipment to be installed is installed, turn the ratchet switch to the extended state, drive the robotic arm to stretch the grasping device away from the equipment to be installed to a safe position. After disconnecting the connection between the return force wire rope and the equipment to be installed, remove the adapter and the guide pin installed on the equipment to be installed.

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