A method for the smooth escape of the manipulator for disassembling and assembling the bolster spring of a railway freight car bogie

Abstract

The invention relates to the technical field of intelligent equipment for railway freight car maintenance, and specifically to a method for the smooth escape of a railway freight car bogie pillow spring disassembly and assembly robot. Different robot escape movement strategies can be adopted according to different trapped states of the trapped pillow spring, and a robot impedance control escape algorithm is proposed for possible collisions during the escape of the robot. The collision force threshold between the robot and the environment is set, and the displacement of the robot is calculated according to force feedback data of a three-dimensional force sensor at the end of the robot, so as to achieve a dynamic balance between the end position of the robot and the collision force, thereby avoiding a rigid collision between the robot and the bogie or other pillow springs during the process of grasping and moving the target pillow spring, and achieving smooth escape of the pillow spring.

Description

Technical Field

[0001] The invention relates to the technical field of intelligent equipment for railway freight car maintenance, and in particular to a method for smoothly getting out of trouble for a railway freight car bogie spring disassembly and assembly robot. Background Art

[0002] At present, when disassembling and installing the vibration damping device of the bogie, manual handling is usually adopted to carry the pillow springs and the wedges. However, the weight of each pillow spring is more than 10kg, which leads to very high labor intensity and low efficiency for the workers. At the same time, it is easy to cause dangerous situations during the installation process due to hand slippage and loss of strength. Based on this, a pillow spring disassembly manipulator and a pillow spring installation manipulator are proposed for the pillow spring disassembly and installation operation. The disassembly and installation of the wedges and pillow springs on the bogie are realized by adding an end manipulator to a six-axis robot.

[0003] However, due to the manufacturing errors of the pillow springs and side frames and the differences in the working conditions such as the load of the vehicle operation, the position and top clearance of each pillow spring in each bogie during maintenance are random. Once the state of the work object is different, the pillow spring is very likely to interfere with the positioning pins on the top of the side frame, which can easily cause the positioning pins to get stuck during the removal of the pillow spring and tip over during the installation process. Currently, there is a lack of a manipulator control method for the pillow spring to be released from the trap, and the pillow spring can only be released by manually adjusting the position of the pillow spring, which is inefficient. Summary of the invention

[0004] In view of the above problems, an embodiment of the present invention provides a method for smoothly getting out of trouble for a railway freight car bogie bogie bolster spring disassembly and assembly robot.

[0005] An embodiment of the present invention provides a method for smoothly getting out of trouble for a railway freight car bogie bolster spring disassembly and assembly robot, comprising:

[0006] Obtaining position information of the pillow spring and the side frame, and determining trapped information of the pillow spring in combination with the existing three-dimensional models of the pillow spring and the side frame;

[0007] When it is determined based on the trapped information that the pillow spring is stuck with the top positioning pin of the side frame in an inclined posture, a path for the manipulator to reach the center of the upper end surface of the pillow spring is planned based on the position information, and the manipulator is controlled to move to the center of the upper end surface of the pillow spring according to the planned path;

[0008] Use the position-based impedance controller to control the manipulator movement to try to hook the pillow spring;

[0009] In case of successful hooking, confirm that the pillow spring is freed; in case of unsuccessful hooking, control the manipulator to move to the front end of the pillow spring and push the pillow spring straight, then rotate the pillow spring by the manipulator so that the notch on the upper end of the outer spring of the pillow spring is directly behind the positioning pin, and hook the pillow spring again to complete the freeing of the pillow spring.

[0010] Optionally, a process of controlling the movement of the manipulator to try to hook the pillow spring by using a position-based impedance controller includes:

[0011] Set the parameters of the impedance controller, including stiffness, inertia, damping, and expected contact force. The direction of the expected contact force is the contact direction between the pillow spring and the manipulator.

[0012] Control the manipulator to start hooking the pillow spring. During the hooking process, the contact force between the manipulator and the pillow spring is detected in real time through the three-dimensional force feedback device at the end of the manipulator. The contact force is fed back to the impedance controller to calculate the position information of the manipulator, and the movement of the manipulator is controlled in combination with the position information.

[0013] During the hooking process, the contact force continuously converges to the expected contact force. When the contact force reaches the expected contact force and continues for a predetermined time and the pillow spring is still not hooked up, it is confirmed that the pillow spring is not successfully hooked up. Otherwise, it is confirmed that the pillow spring is successfully hooked up.

[0014] Optionally, also include:

[0015] When it is determined based on the trapped information that the pillow spring is trapped in the side frame in a tilted or lying posture, a grasping path of the pillow spring is planned based on the position information;

[0016] Move the manipulator according to the grasping path and grasp the pillow spring;

[0017] After the grasping is successful, a transportation path is planned to carry the pillow spring out of the side frame, and the pillow spring is transported according to the transportation path. During the transportation process, the collision force between the pillow spring and the internal structure of the side frame is detected in real time through the three-dimensional force feedback device at the end of the manipulator;

[0018] When the collision force is not greater than the collision force threshold, it is determined that the pillow spring has not collided with the internal structure of the side frame, and the pillow spring is transported by maintaining the current transport path until it is moved out of the side frame;

[0019] When the collision force is greater than the collision force threshold, the collision force and the position-based impedance controller are used to calculate the displacement information of the manipulator. Based on the displacement information, the manipulator is controlled to move so that the pillow spring is separated from the collision point, and the transport path is replanned to transport the pillow spring until it is moved out of the side frame.

[0020] Optionally, the process of obtaining displacement information of the manipulator by calculating the collision force and the position-based impedance controller, and controlling the manipulator to move so that the pillow spring is separated from the collision point based on the displacement information includes:

[0021] Set the parameters of the impedance controller, including stiffness, inertia, damping, and expected collision force, where the direction of the expected collision force is the same as the direction of the collision force;

[0022] The collision force is fed back to the impedance controller to calculate the position information of the manipulator, and the movement of the manipulator is controlled based on the position information to ensure that the collision force does not exceed the expected collision force during the movement;

[0023] Add a virtual force to the input of the impedance controller. The direction of the virtual force is perpendicular to the direction of the collision force. Under the action of the impedance controller, the manipulator moves along the direction of the virtual force. During the movement, detect whether the collision force disappears.

[0024] When it is detected that the collision force disappears, the virtual force is set to zero, so that the manipulator continues to move along the direction of the expected collision force under the action of the impedance controller. After a predetermined time, the manipulator is controlled to stop moving, completing the pillow spring's separation from the collision point.

[0025] Compared with the prior art, the beneficial effects of the present invention are: different manipulator escape movement strategies are adopted according to the different trapped states of the trapped pillow spring, and in view of the collision that may occur during the manipulator's escape process, a manipulator impedance control escape algorithm is proposed, and the collision force threshold between the manipulator and the environment is set. According to the force feedback data of the three-dimensional force sensor at the end of the manipulator, the manipulator displacement is calculated to achieve a dynamic balance between the manipulator end position and the collision force, thereby avoiding a rigid collision between the manipulator and the bogie or other pillow springs during the process of grasping and moving the target pillow spring, and achieving smooth escape of the pillow spring. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings described herein are used to provide a further understanding of the present invention, constitute a part of the present application, and do not constitute a limitation of the present invention. In the drawings:

[0027] Figure 1 A schematic flow chart of a method for smoothly getting out of trouble for a railway freight car bogie bolster spring disassembly and assembly manipulator provided in an embodiment of the present invention;

[0028] Figure 2 A schematic flow chart of another method for smoothly getting out of trouble for a railway freight car bogie bolster spring disassembly and assembly manipulator provided by an embodiment of the present invention;

[0029] Figure 3 A block diagram of an impedance controller provided by an embodiment of the present invention;

[0030] Figure 4 A schematic diagram of a state in which a pillow spring and a positioning pin are slightly stuck according to an embodiment of the present invention;

[0031] Figure 5 A schematic diagram of a state in which a pillow spring and a positioning pin are severely stuck according to an embodiment of the present invention;

[0032] Figure 6 A schematic diagram of a state in which the notch of the outer spring of the pillow spring provided by the embodiment of the present invention is located directly behind the positioning pin;

[0033] Figure 7 A schematic diagram of a state in which a pillow spring provided by an embodiment of the present invention is trapped in a side frame in an inclined posture;

[0034] Figure 8 A schematic diagram of a state in which a pillow spring provided by an embodiment of the present invention is trapped in a side frame in a flat position;

[0035] Fig. 9 A schematic diagram of a state in which a pillow spring provided by an embodiment of the present invention collides with the internal structure of a side frame during transportation, wherein Figure B is a partially enlarged schematic diagram of Figure A;

[0036] Fig.10 A schematic diagram of the force direction and virtual force direction of the pillow spring provided in an embodiment of the present invention;

[0037] Fig.11 A schematic diagram of the force acting on the collision point between the pillow spring and the side frame provided by an embodiment of the present invention;

[0038] Fig.12 A schematic diagram of a state where the pillow spring provided by an embodiment of the present invention is freed from trouble under the action of a virtual force;

[0039] Fig.13 A schematic diagram of the state of the manipulator provided in an embodiment of the present invention when it reaches the center of the upper end surface of the pillow spring and is ready to hook the pillow spring. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments and the accompanying drawings. Here, the illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0041] See also Figure 1 The embodiment of the present invention provides a method for smoothly getting out of trouble for a railway freight car bogie bolster spring disassembly and assembly manipulator, comprising:

[0042] Step 1: Obtain position information of the pillow spring and the side frame, and determine trapped information of the pillow spring in combination with the existing three-dimensional models of the pillow spring and the side frame.

[0043] During implementation, the position information of the side frame and the pillow spring can be obtained through sensors such as industrial cameras or laser radars. The trapped information mainly includes the trapped state and posture information of the pillow spring and the environmental information inside the side frame (including the position of the side frame, the internal structure, and the number and position of other pillow springs inside except the trapped pillow spring). When removing the pillow spring, the pillow spring is easy to get stuck in the side frame in a tilted posture. At this time, it is mainly caused by the interference between the outer spring of the pillow spring and the positioning pin on the top of the side frame. The positioning pin jam can be divided into slight jam and severe jam, as follows: Figure 4 , Figure 5As shown in the figure; during the installation of the pillow spring, there may be installation failures. At this time, the pillow spring is mostly trapped in the bogie side frame in a tilted or lying posture, such as Figure 7 , Figure 8 shown.

[0044] Step 2: Based on the trapped information, it is determined that the pillow spring is stuck with the top positioning pin of the side frame in an inclined posture. Based on the position information, a path for the manipulator to reach the center of the upper end surface of the pillow spring is planned, and the manipulator is controlled to move to the center of the upper end surface of the pillow spring according to the planned path, such as Fig.13 shown.

[0045] In implementation, the path planning process can be completed using an RRT-based path planning algorithm.

[0046] Step 3: Use the position-based impedance controller to control the robot movement to try to hook the pillow spring.

[0047] In practice, the position-based impedance control principle is to achieve control by adjusting the position / speed of the robot end according to the contact force deviation between the robot and the environment. The block diagram of the impedance controller in the present invention is as follows: Figure 3 As shown in the figure, x r Indicates the expected position input of the robot; x f Indicates the desired position correction of the manipulator; x d Indicates the actual position input of the robot; q d represents the input of the robot's motion joint angle; τ represents the robot's joint torque; q represents the actual motion joint angle of the robot; x represents the actual motion position of the robot's end; f e Indicates the actual contact force at the end of the manipulator; f d represents the expected contact force at the end of the manipulator; e f Indicates the manipulator end force correction error.

[0048] In specific implementation, the parameters of the impedance controller can be set, including stiffness, inertia, damping and expected contact force, and the direction of the expected contact force is the contact direction between the pillow spring and the manipulator;

[0049] Control the manipulator to start hooking the pillow spring. During the hooking process, the contact force between the manipulator and the pillow spring is detected in real time through the three-dimensional force feedback device at the end of the manipulator. The contact force is fed back to the impedance controller to calculate the position information of the manipulator, and the movement of the manipulator is controlled in combination with the position information.

[0050] During the hooking process, the contact force continuously converges to the expected contact force. When the contact force reaches the expected contact force and continues for a predetermined time and the pillow spring is still not hooked up, it is confirmed that the pillow spring is not successfully hooked up. Otherwise, it is confirmed that the pillow spring is successfully hooked up.

[0051] Step 4: If the hook is successfully pulled over, confirm that the pillow spring is freed and control the manipulator to withdraw from the side frame; if the hook is not successfully pulled over, control the manipulator to move to the front end of the pillow spring and push the pillow spring straight, and then rotate the pillow spring through the manipulator so that the notch on the upper end of the outer spring of the pillow spring is directly behind the positioning pin. Figure 6 As shown, the reason for doing so is that the notch of the outer spring is lower than other positions on the top of the outer spring, and it is not easy to get stuck with the positioning pin; thereafter, the pillow spring is hooked back to complete the release of the pillow spring and control the manipulator to exit the side frame.

[0052] In summary, for the release from minor jams, the method adopted is to increase the contact force of the manipulator to hook up the pillow spring through the impedance controller, and forcibly hook up the pillow spring; for the release from severe jams, the manipulator needs to push the pillow spring back into the limit groove, and then rotate the pillow spring by the manipulator so that the notch of the outer spring is directly behind the positioning pin, and then hook it up.

[0053] For situations where the bolster springs are trapped in the side frame in a tilted or lying position, see Figure 2 , a railway freight car bogie bolster spring disassembly and assembly manipulator smooth escape method provided by an embodiment of the present invention also includes:

[0054] When it is determined based on the trapped information that the pillow spring is trapped in the side frame in a tilted or lying posture, a grasping path for the pillow spring is planned based on the position information.

[0055] Move the robot according to the grasping path and grasp the pillow spring.

[0056] After successful grasping, a transportation path is planned to carry the pillow spring out of the side frame, and the pillow spring is transported according to the transportation path. During the transportation process, the collision force between the pillow spring and the internal structure of the side frame is detected in real time through the three-dimensional force feedback device at the end of the manipulator.

[0057] When the collision force is not greater than the collision force threshold, it is determined that the pillow spring has not collided with the internal structure of the side frame, and the pillow spring is transported by maintaining the current transport path until it is moved out of the side frame.

[0058] When the collision force is greater than the collision force threshold, it is determined that the pillow spring collides with the internal structure of the side frame, such as Fig. 9 The figure shows a collision situation. After the collision, the collision force and the position-based impedance controller can be used to calculate the displacement information of the manipulator. Based on the displacement information, the manipulator is controlled to move so that the pillow spring is separated from the collision point, and the transportation path is replanned to transport the pillow spring until it is moved out of the side frame.

[0059] In a specific implementation, in order to make the pillow spring separate from the collision point, the parameters of the impedance controller can be set, including stiffness, inertia, damping and expected collision force, and the direction of the expected collision force is the same as the direction of the collision force;

[0060] The collision force is fed back to the impedance controller to calculate the position information of the manipulator, and the movement of the manipulator is controlled based on the position information. During the movement, the collision force is ensured not to exceed the expected collision force, so as to avoid the collision force from continuously increasing and damaging the equipment.

[0061] In order to free the pillow spring, a virtual force is added to the input of the impedance controller at the same time. The direction of the virtual force is perpendicular to the direction of the collision force, such as Fig.10 As shown, the manipulator moves along the direction of the virtual force under the action of the impedance controller, and detects whether the collision force disappears during the movement;

[0062] When the collision force disappears, the virtual force is set to zero, such as Fig.11 As shown, the manipulator continues to move along the direction of the desired collision force under the action of the impedance controller, and the manipulator is controlled to stop moving after a predetermined time, so that the pillow spring is separated from the collision point, as shown in FIG. Fig.12 shown.

[0063] In practical applications, the above-mentioned escape method can be applied to the escape system. The whole escape system consists of seven main parts, including a robot module (including a manipulator), a PLC, an industrial computer, a force control module, a path planning module, a communication module and a force acquisition module; the force acquisition module is composed of a three-dimensional force sensor and a data transmitter; the force control module and the path planning module are arranged on the industrial computer, and the path planning module mainly plans the motion path of the manipulator through the RRT path planning algorithm after receiving the signal sent back by the PLC, and sends it to the robot module through the communication module and the PLC module; the force control module processes the force information collected by the force acquisition module, and starts the impedance controller, formulates an escape strategy, receives force feedback information in real time and calculates the displacement data of the manipulator, and interacts the displacement data with the PLC and the robot module through the communication module, and the PLC sends instructions to the robot module and the industrial computer through the communication module according to the action flow, and the robot module completes the corresponding pillow spring escape action under the instruction of the PLC.

[0064] Embodiment 1

[0065] In the first step, the trapped pillow spring information is input into the path planning module in the industrial computer, which mainly includes the trapped state and posture information of the pillow spring and the environmental information inside the side frame (including the position and internal structure of the side frame, and the number and position of other pillow springs inside the side frame except the trapped pillow spring). The trapped information is generally obtained by obtaining the position information of the side frame and the pillow spring through sensors such as cameras or lidars, and then determined in combination with the existing three-dimensional models of the side frame and the pillow spring; the path planning module performs path planning based on the RRT path planning algorithm. When the path planning module is ready, it transmits signals to the robot module through the PLC and communication module to control the robot to move to the initial position outside the side frame.

[0066] In the second step, when the pillow spring is stuck with the positioning pin in an inclined posture, it is first assumed to be slightly stuck and a strategy of forcibly hooking it down is adopted; a path planning module is used to plan a path for the robot to reach the center of the upper end surface of the pillow spring, and the robot is controlled to move along the path to the center of the upper end surface of the pillow spring, preparing to try to forcibly hook the pillow spring down.

[0067] The third step is to ensure that the contact force of the manipulator in the process of hooking the pillow spring is not too large, turn on the impedance controller, first set the impedance controller parameters stiffness = 300, inertia = 1, damping = 1500, and expected contact force = 200N; after turning on the impedance controller, the impedance controller receives the force information of the three-dimensional force feedback device at the end of the manipulator in real time, obtains the position information of the manipulator through calculation, and transmits it to the robot module to control the manipulator to hook the pillow spring. In this process, the contact force between the manipulator and the pillow spring continues to converge to the expected contact force. If the pillow spring is successfully hooked on the pillow spring receiving device on the manipulator, it means that the pillow spring is successfully freed. It only needs to plan the path through the path planning module to control the manipulator to exit the side frame. If the contact force between the manipulator and the pillow spring reaches the expected contact force, and the pillow spring is not hooked for more than 5 seconds, it is considered that the pillow spring is in a serious stuck state and the escape strategy needs to be changed, then proceed to the next step.

[0068] In the fourth step, the path planning module plans the path, controls the robot to move to the front end of the pillow spring, and then re-plans the path, controls the robot to push the pillow spring straight, and rotates the pillow spring through the pillow spring rotating device on the robot so that the notch on the upper end of the outer spring of the pillow spring is directly behind the positioning pin.

[0069] The fifth step is to control the robot arm through the path planning module to return to the center of the upper end surface of the pillow spring, and re-hook the pillow spring to complete the escape.

[0070] Embodiment 2

[0071] The first step is to input the information of the trapped pillow spring into the path planning module in the industrial computer; after the path planning module is ready, it transmits signals to the robot module through the PLC and communication module to control the robot to move to the initial position outside the side frame.

[0072] In the second step, the path planning module plans a grasping path for the manipulator to grasp the pillow spring. After passing it to the robot module, the robot module moves the manipulator according to this grasping path and grasps the pillow spring, and proceeds to the next step after successful grasping.

[0073] The third step is to use the path planning module to plan a transport path for the manipulator to exit the side frame, pass it to the robot module, and control the manipulator to move along this transport path. At the same time, the force acquisition module needs to be turned on, and the collected force information is input into the industrial computer through the communication module and PLC. The collision force threshold is set to 5N. When the force detected by the force sensor is greater than this threshold, the industrial computer determines that the pillow spring collides with the internal structure of the side frame and proceeds to the next step; if the manipulator has exited the side frame and no force information greater than the collision force threshold is detected in the middle, it is confirmed that the manipulator has completed the escape and has not collided with the internal structure of the side frame in the middle.

[0074] In the fourth step, the industrial computer starts the impedance controller and sets the impedance parameters as stiffness = 300, inertia = 1, damping = 1500, and expected collision force = 20N (the direction of the expected collision force is the same as the direction of the collision force). The impedance controller receives the force information of the three-dimensional force feedback device at the end of the manipulator in real time, obtains the position information of the manipulator through calculation, and transmits it to the robot module to control the movement of the manipulator, ensuring that the contact force between the pillow spring and the internal structure of the side frame does not exceed 20N to ensure the safety of the equipment.

[0075] Step 5: To free the manipulator and the pillow spring, the industrial computer adds a virtual force f to the input of the impedance controller. v =100N, virtual force f v The direction is perpendicular to the direction of the collision force. According to the characteristics of the impedance controller, the manipulator will move in the direction of the virtual force. During the movement, the pillow spring and the internal structure of the side frame are still in contact and impedance control is being performed. When the contact force disappears, it means that the pillow spring has been freed. The industrial computer sets the virtual force to 0 to prevent the manipulator from continuing to move in the direction of the virtual force. After that, due to the characteristics of impedance control, the manipulator will continue to move in the direction of the expected collision force Fd. After waiting for 2 seconds to ensure that the manipulator will not collide again, the industrial computer turns off the impedance controller and sends a signal to the robot module through the communication module and PLC to stop the manipulator from moving.

[0076] In the sixth step, the industrial computer opens the path planning module and replans the path to make the robot exit the side frame. If a collision force is detected during this process, the fourth step is repeated until the robot is out of trouble.

[0077] The solution provided by the embodiment of the present invention adopts different manipulator escape movement strategies according to the different trapped states of the trapped pillow spring, and proposes a manipulator impedance control escape algorithm for the collision that may occur during the manipulator's escape process, sets the collision force threshold between the manipulator and the environment, calculates the manipulator displacement according to the force feedback data of the three-dimensional force sensor at the end of the manipulator, and achieves a dynamic balance between the manipulator's end position and the collision force, thereby avoiding a rigid collision between the manipulator and the bogie or other pillow springs during the process of grasping and moving the target pillow spring, and achieving smooth escape of the pillow spring.

[0078] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A method for smoothly getting out of trouble for a railway freight car bogie bolster spring disassembly and assembly manipulator, characterized in that: include: Obtaining position information of the pillow spring and the side frame, and determining trapped information of the pillow spring in combination with the existing three-dimensional models of the pillow spring and the side frame; When it is determined based on the trapped information that the pillow spring is stuck with the top positioning pin of the side frame in an inclined posture, a path for the manipulator to reach the center of the upper end surface of the pillow spring is planned based on the position information, and the manipulator is controlled to move to the center of the upper end surface of the pillow spring according to the planned path; Use the position-based impedance controller to control the manipulator movement to try to hook the pillow spring; If the hook is successful, confirm that the pillow spring is freed; if the hook is unsuccessful, control the manipulator to move to the front end of the pillow spring and push the pillow spring straight, then rotate the pillow spring by the manipulator so that the notch on the upper end of the outer spring of the pillow spring is directly behind the positioning pin, and hook the pillow spring again to complete the pillow spring freeing; The process of using a position-based impedance controller to control the robot movement to try to hook the pillow spring includes: Set the parameters of the impedance controller, including stiffness, inertia, damping, and expected contact force. The direction of the expected contact force is the contact direction between the pillow spring and the manipulator. Control the manipulator to start hooking the pillow spring. During the hooking process, the contact force between the manipulator and the pillow spring is detected in real time through the three-dimensional force feedback device at the end of the manipulator. The contact force is fed back to the impedance controller to calculate the position information of the manipulator, and the movement of the manipulator is controlled in combination with the position information. During the hooking process, the contact force continuously converges to the expected contact force. When the contact force reaches the expected contact force and continues for a predetermined time and the pillow spring is still not hooked up, it is confirmed that the pillow spring is not successfully hooked up. Otherwise, it is confirmed that the pillow spring is successfully hooked up.

2. A railway freight car bogie bolster spring disassembly and assembly manipulator smooth escape method as claimed in claim 1, characterized in that: Also includes: When it is determined based on the trapped information that the pillow spring is trapped in the side frame in a tilted or lying posture, a grasping path of the pillow spring is planned based on the position information; Move the manipulator according to the grasping path and grasp the pillow spring; After the grasping is successful, a transportation path is planned to carry the pillow spring out of the side frame, and the pillow spring is transported according to the transportation path. During the transportation process, the collision force between the pillow spring and the internal structure of the side frame is detected in real time through the three-dimensional force feedback device at the end of the manipulator; When the collision force is not greater than the collision force threshold, it is determined that the pillow spring has not collided with the internal structure of the side frame, and the pillow spring is transported by maintaining the current transport path until it is moved out of the side frame; When the collision force is greater than the collision force threshold, the collision force and the position-based impedance controller are used to calculate the displacement information of the manipulator. Based on the displacement information, the manipulator is controlled to move so that the pillow spring is separated from the collision point, and the transport path is replanned to transport the pillow spring until it is moved out of the side frame.

3. A railway freight car bogie bolster spring disassembly and assembly manipulator smooth escape method as claimed in claim 2, characterized in that: The process of obtaining displacement information of the manipulator by calculating the collision force and the position-based impedance controller and controlling the manipulator to move so that the pillow spring is separated from the collision point based on the displacement information includes: Set the parameters of the impedance controller, including stiffness, inertia, damping, and expected collision force, where the direction of the expected collision force is the same as the direction of the collision force; The collision force is fed back to the impedance controller to calculate the position information of the manipulator, and the movement of the manipulator is controlled based on the position information to ensure that the collision force does not exceed the expected collision force during the movement; Add a virtual force to the input of the impedance controller. The direction of the virtual force is perpendicular to the direction of the collision force. Under the action of the impedance controller, the manipulator moves along the direction of the virtual force. During the movement, detect whether the collision force disappears. When it is detected that the collision force disappears, the virtual force is set to zero, so that the manipulator continues to move along the direction of the expected collision force under the action of the impedance controller. After a predetermined time, the manipulator is controlled to stop moving, completing the pillow spring's separation from the collision point.

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