A safe and controllable power supply design method for repeated crawling of a robotic arm on track

Abstract

The present invention provides a power supply safety and controllable design method suitable for repeated on-orbit crawling of a robotic arm. By designing a dual-bus power supply system, a multi-channel hierarchical controllable power bus, a multi-level controllable command bus, and a multi-path command drive circuit, an effective electrical link control strategy and power link safety management are provided for the on-orbit crawling mission of the space station robotic arm.

Description

Technical Field

[0001] The invention belongs to the field of spacecraft power supply and distribution system design, and relates to a safe and controllable power supply design method suitable for repeated on-orbit crawling of a robotic arm. Background Art

[0002] The robotic arm adopts a 7-degree-of-freedom robotic arm solution, and the main body consists of 7 joints, 2 end effectors, 2 arm rods, 1 central controller and 1 visual camera system. In order to cover the needs of the entire space station envelope for robotic arm support tasks, the robotic arm adopts a "crawling" method, and the end effector is used to dock and separate multiple times with the target adapter installed on the cabin wall to achieve the movement requirements on the cabin surface.

[0003] Before the space station mission, my country's aerospace industry was still in the exploratory stage for the on-orbit mission support of the robotic arm. A surface-access robotic arm was installed on the Chang'e-5 satellite to achieve the lunar sampling mission. The surface-access robotic arm adopts a fixed structure. During the mission, the robotic arm does not move, and the power and information links supporting the operation of the robotic arm remain connected. This design cannot meet the needs of the space station robotic arm repeatedly "crawl" on orbit, and the power and information links need to be connected and disconnected multiple times when moving to different target adapters in the cabin.

[0004] 1) Electrical link control strategy

[0005] Domestic manned space flight has achieved the connection and separation of two spacecraft through rendezvous and docking. The electrical interface between the two spacecraft includes: grid power supply and information bus interface. In the preparation stage of the rendezvous and docking of the two spacecraft, the grid power supply interface and the information bus interface are always in the disconnected state through the execution switch to ensure that the electrical interfaces of the docking surfaces of the two spacecraft are not powered during the entire rendezvous and docking process. After the rendezvous and docking is completed and the combination is formed, the switch is controlled to be turned on to achieve the connection of the grid power supply and information bus communication between the two spacecraft.

[0006] The above electrical link control strategy does not meet the mission requirements of the space station manipulator, mainly manifested as follows:

[0007] During the on-orbit "crawling" mission of the space station's robotic arm, the electrical link needs to transmit multiple information channels, including: power interface, command bus interface, remote control command interface, telemetry parameter interface, information bus interface, and Ethernet network interface. In different "crawling" states of the robotic arm, the working states of each stand-alone device are different. The power link must adopt multi-channel hierarchical control, and the electrical link control strategy is more complicated. At the same time, the information link cannot be completely disconnected, and there is a need for live plugging and unplugging, and the interface circuit needs to take safety protection measures.

[0008] 2) Power link safety management

[0009] To ensure the safety of astronauts' extravehicular operations, safety hazards such as short circuits and leakage must be eliminated on the 100V high-voltage power transmission path. In the rendezvous and docking mission, the power supply bus adopts a single bus and relay switch control, which does not have intelligent management capabilities. In the event of a fault, the grid-connected power supply link can only be disconnected, resulting in the failure of the grid-connected mission of the assembly. This design cannot meet the space station's goal of "one fault to ensure business continuity, and two faults to ensure spacecraft safety." The on-orbit "crawling" mission of the robotic arm requires the intelligent management of the power bus, and the safety of astronauts must be ensured in the event of a fault, and the completion of the mission must be ensured under ground support conditions.

[0010] Therefore, my country's current successful experience in the Chang'e-5 robotic arm and rendezvous and docking missions is not applicable to the high-reliability and repeated "crawl" mission requirements of the space station robotic arm in orbit. Summary of the invention

[0011] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art, to provide a safe and controllable power supply design method suitable for the repeated crawling of a robotic arm on track, to provide an effective electrical link control strategy and a power link safety management method for the robotic arm during the crawling process of the robotic arm on track.

[0012] The technical solution of the present invention is: a design method for safe and controllable power supply suitable for repeated crawling of a robot arm on track, comprising:

[0013] Before crawling, the robot arm is locked and fixed on the target adapter HXC-C;

[0014] Execute the power-on status setting process for each single unit of the fixed end effector;

[0015] At the beginning of crawling, the robot arm moves to the top of the target adapter HXC-A required by the task, and the free end end effector captures, drags and locks the target adapter HXC-A. At the same time, the self-controlled docking floating electrical connector at the front end of the locking mechanism completes docking with the electrical connector on the target adapter HXC-A to achieve electrical connection;

[0016] Execute the power-off process of the fixed-end end effector;

[0017] Execute the free end end effector power-on process;

[0018] The end effector fixed with the target adapter HXC-C is locked and released, and the multi-joint linkage of the robot arm adjusts the configuration;

[0019] The robotic arm crawls to the task required position and is locked and fixed with the target adapter HXC-A.

[0020] Before crawling, the fixed end end effector of the robotic arm is locked and fixed on the target adapter HXC-C. The target adapter HXC-C is equipped with an automatic docking floating electrical connector socket, and the fixed end end effector is equipped with an automatic docking floating electrical connector plug. Through the connection between the automatic docking floating electrical connector plug and the socket, the power and electrical information in the space station are transmitted to the end effector of the robotic arm.

[0021] The power-on status setting process of each single machine includes: 100V primary bus power-on status setting in the robot arm, secondary bus power-on status setting, and instruction bus power-on status setting.

[0022] The 100V primary busbar power-on state setting adopts a three-level power distribution control system in series, and the specific design is as follows:

[0023] Primary power distribution: implemented by the power control unit in the space station cabin

[0024] The power control unit in the space station cabin provides four 100V buses and one 29V command bus for the robotic arm. Each 100V bus is on and off controlled in the power control unit to achieve the first-level control of power distribution.

[0025] Secondary power distribution: realized by the end power supply module in the end effector of the robot arm

[0026] The 4-way 100V and 29V command buses output by the space station power control unit are input to the terminal power supply module. The 4-way 100V buses and 29V command buses are designed with relays to control on and off in the terminal power supply module.

[0027] The on / off of the first 100V bus and the 29V command bus is controlled by the space station computer, and the on / off of the remaining three 100V buses is controlled by the end controller of the robotic arm.

[0028] The terminal power supply module divides the 100V bus of the first route to obtain the main and standby heat control buses for heating control of the robot arm controller;

[0029] Three-level power distribution: realized by a single machine inside the robot arm;

[0030] The terminal power supply module provides a power supply bus for the terminal controller;

[0031] The 100V bus is split in the joint and sent to the motor power module in the joint, and then transmitted to the next joint. The joint controller controls the power on and off of the power module by controlling the enable end of the motor power module.

[0032] In the central controller, the 100V bus is divided and sent to the central controller electronic components and other equipment, and then transmitted to the next joint;

[0033] Each product is designed with an on-off control switch. The space station directly controls the power on and off of the terminal controller and the central controller, and the central controller controls the power on and off of the joint controller.

[0034] In the primary power distribution, there are 4 100V busbars, and the power distribution is divided as follows:

[0035] The first 100V bus supplies power to all controllers and heaters controlled by the controllers;

[0036] The second 100V bus supplies power to all joint motors;

[0037] The third 100V busbar supplies power to the thermal control of the boom and arm temperature relays;

[0038] The fourth 100V busbar supplies power to the forearm in combined arm mode.

[0039] The secondary bus power-on status settings include: adopting a decentralized power distribution system, implemented by a DC / DC power module, including a single-machine power module, a 200W power module, a 100W power module, and a 50W power module.

[0040] The specific design of the DC / DC power supply module is as follows:

[0041] The single-machine power supply module is installed inside the single machine to provide ±12V and 5V power for the single machine CPU, FPGA, interface chip, etc. The main and standby power supply modules supply power to the main and standby circuits respectively;

[0042] Two 200W power modules are installed in each joint to achieve 100V to 28V bus conversion, respectively supplying power to the main and backup motors in the joint;

[0043] Two 100W / 28V power modules are installed in the end controller to achieve 100V to 28V bus conversion, which supplies power to the main and standby windings of the end effector motor respectively;

[0044] Two 50W power modules are installed in the central controller of the robot arm and used in parallel to achieve 100V to 29.5V bus conversion, which serves as the internal command power supply of the robot arm and provides power for the single-machine relay package inside the robot arm.

[0045] The command bus power-on state setting includes: adopting a multi-level controllable command bus system, the specific design is as follows:

[0046] The 29V space station command bus input from the space station is directly provided to the relay line package for powering on and off the first 100V bus in the terminal power supply module and the 29V command bus in the space station;

[0047] After the terminal power supply module controls the 29V command bus of the space station, it provides the terminal controller and the central controller with the power on / off relay line package;

[0048] The 29V robot command bus A, which is transformed in parallel by two 50W power modules in the robot central control component, is provided to the joint controller and other equipment for switching on and off, and the 2nd, 3rd, and 4th 100V bus plus power-off relay line package in the terminal power supply module;

[0049] After the robot command bus A is controlled in the terminal controller, a 29V robot command bus B is formed, which is output through diode isolation to the relay line package that cuts off the power of the first 100V bus in the terminal power supply module to ensure that in the event of a fault, the robot can automatically disconnect the first 100V bus.

[0050] In the normal working mode, a single control machine selects an instruction bus to execute the power on and off control, which is a single-path instruction drive circuit; when encountering an emergency fault, the first 100V bus is powered off and a multi-path instruction drive circuit is designed, which can be controlled and driven by the space station computer or by the robotic arm itself; during the crawling process, once an emergency fault that affects safety occurs, the robotic arm will automatically disconnect the 100V power input bus at the first time to ensure that the 100V power bus is not powered and the robotic arm product is safe.

[0051] The process of executing the power-on and power-off of the fixed-end end effector includes: according to the working mode requirements of each single machine during the crawling process of the robot arm, each control single machine selects different command buses and drives the execution switch to realize the power-on and power-off of the single machine or the bus.

[0052] The advantages of the present invention compared with the prior art are:

[0053] 1) Design a dual-bus power supply system, which can ensure the safety of the robot arm product in the event of a single bus power failure, and can continue to perform tasks after the bus returns to normal;

[0054] 2) Design a multi-channel hierarchical controllable power bus to effectively isolate overcurrent or short-circuit faults in the power link. The upper power link uses a solid-state power electronic switch SSPC to achieve intelligent management of the power bus, and the lower power link uses redundant relay switch control, which is used in series with the upper SSPC switch, and the parameters of the upper and lower devices match. When an overcurrent or short-circuit fault occurs in the power link, the upper SSPC switch is disconnected first, and the lower relay withstands the allowable overload, effectively isolating the faulty line. When the fault mode is eliminated, the power link can work normally, which can ensure the power supply safety of the robot arm's repeated "crawling" tasks on track;

[0055] 3) Design a multi-level controllable command bus. According to the working mode requirements of each single machine during the crawling process of the robot arm, each control unit selects a different command bus and drives the execution switch to realize the power on and off of the single machine / bus;

[0056] 4) Design a multi-path instruction drive circuit. For the power off of the 100V bus, a multi-path instruction drive circuit is designed. It can be driven by the space station computer or by the robot. During the crawling process, if an emergency failure that affects safety occurs, the robot can disconnect the 100V power bus immediately to ensure that the 100V power bus is not plugged in with power, and the robot is safe.

[0057] 5) Select an automatic docking floating electrical connector that can withstand the space environment to achieve reliable connection and transmission of power and electrical information between the equipment in the space station cabin and the robotic arm. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 This is the flow chart of the robot arm crawling process. DETAILED DESCRIPTION

[0059] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0060] According to the layout of the target adapters used by the robotic arm on the space station, an on-orbit crawling sequence plan is formulated. When carrying out on-orbit crawling tasks, the conventional route is preferred. When the conventional route cannot meet the needs, a special route is selected, and the "original route to the original route and back" is guaranteed as much as possible, so that the fixed end of the robotic arm on each adapter is determined.

[0061] The present invention discloses a design method for safe and controllable power supply for repeated on-orbit crawling of a robotic arm. The "robotic arm" adopts a 7-degree-of-freedom robotic arm solution, and the main body is composed of 7 joints, 2 end effectors, 2 arm rods, 1 central controller and 1 visual camera system. The "crawling" method is: the end effector of the robotic arm is repeatedly docked and separated with the target adapter installed on the bulkhead to achieve the movement requirements on the surface of the cabin. Taking crawling from the target adapter HXC-C installed on the bulkhead to the target adapter HXC-A as an example, before the crawling task starts, one end effector of the robotic arm is locked with HXC-C, and the other end effector is in a free release state. The end effector locked with HXC-C is called the fixed end, and the end effector in the free release state is called the free end. After the crawling task is completed, the end effector of the free end of the robotic arm is locked with HXC-A, and the end effector of the fixed end is in a free release state. Figure 1 As shown in the figure, the design of safe and controllable power supply when the robot arm crawls is as follows:

[0062] 1) Before crawling, the robot arm is locked and fixed on the target adapter HXC-C, and the SSPC of the 4-way 100V bus in the power control unit in the cabin is turned on and input to the fixed end effector through HXC-C.

[0063] Step 1: The 100V power bus of the space station adopts an independent topology design of A and B dual buses, which are safely isolated and have the ability to be repaired, replaced and restored on orbit in case of failure;

[0064] Step 2: The 100V power busbars 1, 2, and 4 use the space station B power busbar to provide all control stand-alone work for the robotic arm. If the space station B busbar loses power in the event of a fault, the robotic arm will be in a low-temperature thermal control state and the entire arm will be safe. After the fault is eliminated, the robotic arm can work normally;

[0065] Step 3: The third 100V power bus uses the space station A power bus to provide a temperature control path for the robot arm temperature relay. If the space station A bus loses power in the event of a fault, the active temperature control function of the B bus controller is activated, and all functions and performances of the robot arm subsystem are not affected.

[0066] Step 4: In the power control unit in the cabin, the 4 100V busbars are all connected / disconnected by a 10A solid-state power electronic switch SSPC, which has an I2t inverse time protection function. The maximum unprotected current of the 10A SSPC product is 14A, the minimum protected current is 16A, and more than 50A is considered a load short circuit.

[0067] Step 5: There is a fuse at the front end of the SSPC as a backup protection method for overcurrent. When an overcurrent or short circuit occurs in the distribution line, the SSPC is first disconnected to isolate the related fault line. When the fault is repaired, the SSPC is closed again. Two 10A fuses are selected in parallel, with a fusing current of about 65A and a fusing time of within 2ms to 5s.

[0068] 2) Execute the power-on status setting process for each single machine. The 4-way 100V bus control relay of the end power supply module in the end effector is turned on to meet the power supply requirements of the equipment during the crawling process.

[0069] Step 1: The 4-way 100V bus control relays of the end power supply module in the end effector all adopt a double relay multi-contact parallel design, and the 4-way 100V power supply paths all adopt an isolation design to meet the requirement that the isolation impedance is greater than 10M.

[0070] Step 2: The 100V control relay adopts a derating design. The rated current of the single contact of the relay that controls the 1st, 2nd and 4th 100V plus power-off is 25A, and the overload is 50A. Each control uses a double relay with two pairs of contacts in parallel, that is, each channel can withstand a rated current of 100A and an overload of 200A. Therefore, when the short-circuit current is greater than 50A, the front-end SSPC is disconnected, and the relay contacts can withstand this overload without damage;

[0071] Step 3: The relay that controls the 3rd 100V power on and off uses a single contact with a rated current of 10A and an overload of 20A, that is, each channel can withstand a rated current of 40A and an overload of 80A. Therefore, when the short-circuit current is greater than 50A, the SSPC is disconnected, and the relay contacts can withstand this overload without damage.

[0072] 3) The 4-way 100V bus provided by the cabin power control unit connected to the HCX-A target adapter is in the disconnected state, and the 4-way 100V bus control relay in the free end end effector power supply module is in the disconnected state.

[0073] 4) According to the instruction, the free end end effector executes the process of capturing the HXC-A target adapter. The free end end effector captures, drags and locks the target adapter HXC-A. At the same time, the self-controlled docking floating electrical connector at the front end of the locking mechanism completes docking with the electrical connector on the target adapter to achieve electrical connection;

[0074] Step 1: After the rough positioning and precise docking of the mechanism, the floating docking electrical connector socket at the target adapter end is docked with the floating docking electrical connector plug at the end effector end to achieve connectivity of the electrical link;

[0075] Step 2: The self-controlled docking floating electrical connector is a 6-DOF floating electrical connector with high docking benchmark requirements. The floating device maintains a certain offset in all 6 DOF directions. It transmits a lot of electrical information, and different types of information such as high-power, low-frequency information, and high-speed data are mixed and transmitted. It has strong anti-electromagnetic interference. It has high space environment resistance and meets the low-orbit anti-proton oxygen performance for more than 15 years. The mechanical life is required to be more than 6,000 times. During the plugging process, there is a plug-in temperature difference of about 200 degrees between the plug and the socket. After plugging, the elastic element is subjected to pressure and torsional torque for a long time. After multiple high and low temperature alternating temperature shocks, it can still meet multiple separation and plug-in tasks.

[0076] Step 3: The 4-way 100V busbars are in the disconnected state, and the power busbars are plugged in without power, which can ensure the safety of the high-voltage power circuit;

[0077] Step 4: The command power supply of the space station is a public power supply. The 29V command bus is powered on during the flight mission. Therefore, the 29V command bus at the HXC-A target adapter is always powered, and the floating electrical connector is designed as a pin. The load of the command power supply is a relay, which needs to be driven by a command to form a current path. During the plugging process of the free-end end effector and the HXC-A target adapter, the space station has no command drive, and the command power supply has no current output, which will not affect the command power supply of the space station. At the same time, the electrical connection is verified to be reliable and safe through the grasping test and the hot plug test of the command bus interface.

[0078] Step 5: The space station remote control commands introduced into the end effector through the target adapter are all product power-off commands, the load is the relay line package, and the command drive of the digital tube equipment in the cabin is in the form of OC gate. The command line of the HXC-A target adapter end in the initial state is a suspended state without load, which has no effect on the digital tube equipment in the cabin; when the end effector is plugged into the target adapter, the command is in an undriven state, and connecting the relay line package will not generate a current path, which will not affect the command interface of the digital tube equipment.

[0079] Step 6: The telemetry parameters are output after resistor isolation. The initial telemetry of the HXC-A target adapter is suspended, which has no effect on the digital tube device; when the end effector is plugged into the target adapter, the analog telemetry output of the robot arm product is less than 5V, and the voltage has no effect on the digital tube device during connection.

[0080] Step 7: The information bus uses transformer coupling and supports hot plugging. What is plugged in is the branch line of the information bus, and there is no problem of matching resistance influence.

[0081] Step 8: The Ethernet interface supports hot swapping while powered on.

[0082] 5) Execute the power-off process of the end effector of the fixed end of the manipulator, power off the in-cabin power control unit connected to the HXC-C target adapter, and disconnect the 4-way 100V bus control relay of the end power supply module in the fixed end effector;

[0083] Step 1: Redundancy measures are taken on the command drive link for the power failure of the 100V bus. In normal working mode, the power failure of the 100V bus is selected by the space station digital tube computer to drive the space station command bus. In emergency failure mode, the robot end controller selects the robot command bus B drive, and the robot can disconnect the 100V bus by itself in the first time to ensure that the 100V power bus is not plugged in with power, and the robot product is safe.

[0084] Step 2: The power failure of the 2nd to 4th 100V busbars can be controlled by the robot end controller, which adopts a master and standby single-machine design.

[0085] 6) Execute the power-on process of the manipulator, the 4-way 100V bus provided by the cabin power control unit connected to the HCX-A target adapter is turned on, and input to the free end end effector through HXC-A, and the 4-way 100V bus control relay of the end power supply module in the free end end effector is turned on;

[0086] 7) After the robot arm status is confirmed to be normal, the fixed end effector connected to the HXC-C target adapter performs the disengagement process;

[0087] 8) Complete the crawling of the target adapter HXC-C to HXC-A.

[0088] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A design method for safe and controllable power supply for repeated crawling of a robot arm on track, characterized in that include: Before crawling, the robot arm is locked and fixed on the target adapter HXC-C; Execute the power-on status setting process for each single unit of the fixed end effector; At the beginning of crawling, the robot arm moves to the top of the target adapter HXC-A required by the task, and the free end end effector captures, drags and locks the target adapter HXC-A. At the same time, the self-controlled docking floating electrical connector at the front end of the locking mechanism completes docking with the electrical connector on the target adapter HXC-A to achieve electrical connection; Execute the power-off process of the fixed-end end effector; Execute the free end end effector power-on process; The end effector fixed with the target adapter HXC-C is locked and released, and the multi-joint linkage of the robot arm adjusts the configuration; The robotic arm crawls to the mission required position and is locked and fixed with the target adapter HXC-A; The power-on status setting process of each stand-alone machine includes: setting the power-on status of the 100V primary bus in the robot arm, setting the power-on status of the secondary bus, and setting the power-on status of the command bus; The 100V primary busbar power-on state setting adopts a three-level power distribution control system in series, and the specific design is as follows: Primary power distribution: implemented by the power control unit in the space station cabin The power control unit in the space station cabin provides four 100V buses and one 29V command bus for the robotic arm. Each 100V bus is on and off controlled in the power control unit to achieve the first-level control of power distribution. Secondary power distribution: realized by the end power supply module in the end effector of the robot arm The 4-way 100V and 29V command buses output by the space station power control unit are input to the terminal power supply module. The 4-way 100V buses and 29V command buses are designed with relays to control on and off in the terminal power supply module. The on / off of the first 100V bus and the 29V command bus is controlled by the space station computer, and the on / off of the remaining three 100V buses is controlled by the end controller of the robotic arm. The terminal power supply module divides the 100V bus of the first route to obtain the main and standby heat control buses for heating control of the robot arm controller; Three-level power distribution: realized by a single machine inside the robot arm; The terminal power supply module provides a power supply bus for the terminal controller; The 100V bus is split in the joint and sent to the motor power module in the joint, and then transmitted to the next joint. The joint controller controls the power on and off of the power module by controlling the enable end of the motor power module. In the central controller, the 100V bus is divided and sent to the central controller electronic components and then transmitted to the next joint; Each product is designed with an on-off control switch. The space station directly controls the power on and off of the terminal controller and the central controller, and the central controller controls the power on and off of the joint controller. The command bus power-on state setting includes: adopting a multi-level controllable command bus system, the specific design is as follows: The 29V space station command bus input from the space station is directly provided to the relay line package for powering on and off the first 100V bus in the terminal power supply module and the 29V command bus in the space station; After the terminal power supply module controls the 29V command bus of the space station, it provides the terminal controller and the central controller with the power on / off relay line package; The 29V robot command bus A, which is transformed in parallel by two 50W power modules in the robot central control component, is provided to the joint controller switch and the 2nd, 3rd, and 4th 100V bus plus power-off relay wire package in the terminal power supply module; After the robot command bus A is controlled in the terminal controller, a 29V robot command bus B is formed, which is output through diode isolation to the relay line package that cuts off the power of the first 100V bus in the terminal power supply module to ensure that in the event of a fault, the robot can automatically disconnect the first 100V bus.

2. A design method for safe and controllable power supply for repeated crawling of a robot arm on track as claimed in claim 1, characterized in that: Before crawling, the fixed end end effector of the robotic arm is locked and fixed on the target adapter HXC-C. The target adapter HXC-C is equipped with an automatic docking floating electrical connector socket, and the fixed end end effector is equipped with an automatic docking floating electrical connector plug. Through the connection between the automatic docking floating electrical connector plug and the socket, the power and electrical information in the space station are transmitted to the end effector of the robotic arm.

3. A design method for safe and controllable power supply for repeated crawling of a robot arm on track as claimed in claim 2, characterized in that: In the primary power distribution, there are 4 100V busbars, and the power distribution is divided as follows: The first 100V bus supplies power to all controllers and heaters controlled by the controllers; The second 100V bus supplies power to all joint motors; The third 100V busbar supplies power to the thermal control of the boom and arm temperature relays; The fourth 100V busbar supplies power to the forearm in combined arm mode.

4. A design method for safe and controllable power supply for repeated crawling of a robot arm on track as claimed in claim 3, characterized in that: The secondary bus power-on status settings include: adopting a decentralized power distribution system, implemented by a DC / DC power module, including a single-machine power module, a 200W power module, a 100W power module, and a 50W power module.

5. A design method for safe and controllable power supply for repeated crawling of a robot arm on track as claimed in claim 4, characterized in that: The specific design of the DC / DC power supply module is as follows: The single-machine power supply module is installed inside the single machine to provide ±12V and 5V power for the single machine CPU, FPGA, and interface chip. The main and standby power supply modules supply power to the main and standby circuits respectively; Two 200W power modules are installed in each joint to achieve 100V to 28V bus conversion, respectively supplying power to the main and backup motors in the joint; Two 100W / 28V power modules are installed in the end controller to achieve 100V to 28V bus conversion, which supplies power to the main and standby windings of the end effector motor respectively; Two 50W power modules are installed in the central controller of the robot arm and used in parallel to achieve 100V to 29.5V bus conversion, which serves as the internal command power supply of the robot arm and provides power for the single-machine relay package inside the robot arm.

6. A design method for safe and controllable power supply for repeated crawling of a robot arm on track as claimed in claim 5, characterized in that: In normal working mode, a single control machine selects an instruction bus to execute power on and off control, which is a single-path instruction drive circuit; when encountering an emergency fault, a multi-path instruction drive circuit is designed to cut off the power to the 100V bus, which can be controlled and driven by the space station computer and by the robotic arm itself; during the crawling process, once an emergency fault that affects safety occurs, the robotic arm will automatically disconnect the 100V power input bus at the first time to ensure that the 100V power bus is not powered and the robotic arm product is safe.

7. A method for designing safe and controllable power supply for repeated crawling of a robot arm on track as described in any one of claims 1 to 6, characterized in that: The process of executing the power-on and power-off of the fixed-end end effector includes: according to the working mode requirements of each single machine during the crawling process of the robot arm, each control single machine selects different command buses and drives the execution switch to realize the power-on and power-off of the single machine or the bus.

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