Virtual-simulation-platform-based verification method for tool changing of tunnel boring machine

Abstract

A virtual-simulation-platform-based verification method for the tool changing of a tunnel boring machine. By means of the method, a motion simulation and state monitoring function for an automatic tool-changing robot for a tunnel boring machine is developed on the basis of the Unity game engine. The method comprises: motion simulation, which involves a user designing a start pose and an end pose of a robot in a virtual environment, and completing path planning for the robot; three-dimensional visual monitoring, which involves monitoring an operation state of the robot, and presenting the operation state in a three-dimensional manner; and operation state reproduction, which involves storing operation data of the robot, and reproducing the operation state when the user inputs a historical time node. The problems of high costs, low efficiency, low accuracy and poor safety during a change of a large-scale disc cutter are solved, so as to realize the real-time visual monitoring of a tool-changing robot, thereby improving the operation safety of the tool-changing robot; and technical verification, such as robot trajectory planning and motion simulation, can be performed in a virtual system. A database is constructed for data of a virtual environment, so as to store key operation parameters of the robot, thereby improving the reproduction of an operation state of the robot.

Description

A virtual simulation platform verification method for shield machine tool changing TECHNICAL FIELD

[0001] The present application relates to the technical field of large rolling tool changing, in particular to a virtual simulation platform verification method for shield machine tool changing. BACKGROUND

[0002] At present, in the field of large rolling tool changing, it mainly relies on manual work and some auxiliary tools, and the process is complicated and inconvenient. In order to reduce labor costs, a special mechanical arm is introduced in the process of changing tools, and the self-changing of the mechanical arm to the large rolling tool is completed through visual positioning and other ways. Since the robot is used to change the tool of the shield machine, the sudden obstacle and the actual obstacle are considered, the robot trajectory is planned according to the actual tool changing grabbing position of the shield machine, and the optimal motion path result is output for the robot.

[0003] SUMMARY

[0004] In view of the problems of high cost, low efficiency, low accuracy and poor safety in large rolling tool changing, a virtual simulation platform verification method for shield machine tool changing is proposed.

[0005] The virtual simulation platform is used to simulate and verify the motion trajectory of the robot, and the optimal motion planning result is given, and the device running information is displayed and stored.

[0006] The technical scheme of the present application is:

[0007] A virtual simulation platform verification method for shield machine tool changing is realized through the following process:

[0008] Motion simulation: let the user design the starting and ending pose of the robot in the virtual environment, complete the path planning of the robot, verify the safety of the path before the actual work of the robot, and use the collision detection technology to find the collision points in the path in advance;

[0009] Three-dimensional visual monitoring: monitor and three-dimensionally display the running state of the robot, including the speed, acceleration and angle of each axis of the robot;

[0010] Running state reproduction: store the running data of the robot, and the user can reproduce the running state by inputting the historical time node;

[0011] The specific implementation steps are as follows:

[0012] Step S1: first, based on the virtual simulation platform development system, all the corresponding requirements can be intuitively displayed and operated through the interface;

[0013] Step S2: Import the model of the corresponding shield automatic tool changer robot and tool space pose simulation mechanism into the virtual simulation platform, and establish a scale environment model in the virtual platform that completely corresponds to the actual object and spatial layout;

[0014] Step S21: Perform motion control on the joints of the robot in the virtual environment, input the corresponding rotation angle of each joint through the virtual simulation platform, and move the mechanical arm to the specified position to design the teaching point for the robot twin model;

[0015] Step S22: Select the mode of trajectory planning, and use the forward and inverse kinematics of the robot and the trajectory planning algorithm to plan the trajectory of the robot according to the teaching points designed by the user, to obtain the planning sequence, wherein the trajectory planning algorithm is written in the form of a script in the virtual simulation platform, and interpolation is performed using related functions in the virtual simulation platform to realize motion;

[0016] Step S23: Perform motion simulation analysis and collision detection, and use the virtual environment to perform motion simulation on the planning results, and call the collision detection algorithm during the simulation process;

[0017] Step S24: If a collision is detected during the simulation process, a collision prompt is given, and the collision detection is realized based on the bounding box technology;

[0018] Step S25: Track the end trajectory to visually display the motion trajectory, output the planning results, control the physical entity, and then import the results into the controller to control the motion of the physical robot;

[0019] Step S3: Establish a virtual system using the virtual simulation platform, map the twin data into the virtual system, synchronize the virtual system and the physical entity, make the three-dimensional model in the virtual system and the real device run synchronously, display and store the device operation information, update the model attributes in each frame through the control of the logic layer script, make the model follow the real device to move synchronously, and display the current device operation data;

[0020] Step S4: For the data transmitted by the server, on the one hand, it is mapped to the model as real-time data to drive the model motion, and on the other hand, it is stored in the database as the data source for querying the historical working state; The system adopts C / S architecture, that is, it is composed of a client and a server, the robot controller is the server, and the simulation monitoring system established by the virtual simulation platform is the client; Socket is used to realize the communication between the server and the client;

[0021] Select a database as the data storage platform, load the database plug-in in the virtual simulation platform, develop the database operation class SQL class, and encapsulate the connection, closing, adding, deleting, modifying and querying operations of the database as methods.

[0022] Preferably, the virtual simulation platform is Unity3D software.

[0023] Preferably, the database is a MySQL database.

[0024] Further, in step S1, the interface includes a monitoring start panel, a running state reproduction panel, a motion simulation panel and a data display panel.

[0025] Further, in step S22, the trajectory planning algorithm is written in the virtual simulation platform in the form of a script, and interpolation is performed by using related functions in the virtual simulation platform to realize motion; wherein, joint space interpolation is realized by using Mathf.Lerp, and the return value is a floating point number; straight line interpolation is realized by using Vector3.Lerp, and the return value is a three-dimensional vector; by changing the value of time in each frame of animation, that is, in the Update() method, the return value is changed, and then the joint rotation angle is changed to form a continuous animation.

[0026] Further, in step S22, the mode of trajectory planning includes joint planning, straight line planning and circular arc planning.

[0027] Further, in step S24, collision detection is realized by using a bounding box-based technology, and specifically:

[0028] Step S241 obtains the AABB bounding box of the detection object as the root node of the tree;

[0029] Step S242 finds the longest axis of the bounding box, takes the midpoint of the axis as the split point, makes a plane perpendicular to the split axis through the split point, that is, the split plane, and divides the triangular patches of the model into two subsets according to the split plane, and for the triangular shape located on the split plane, it is divided into the collection with less triangular shapes;

[0030] Step S243 constructs the bounding box for the divided collection as the left and right child nodes of the parent node, and repeats the process of step S242 and step S243.

[0031] Further, in step S3, the monitoring data includes the control value of each axis, the motor operation mode, the actual position of the motor, the joint angle, the joint speed, the joint acceleration and the joint torque.

[0032] The present application has the advantages of:

[0033] 1. The present application improves the synchronization between the virtual platform and the robot by building a twin data mapping, and the spatial information capture accuracy of the mechanical arm is ≤0.5mm.

[0034] 2、The application adopts the mixed hierarchical bounding box to construct the model, and effectively reduces the average time required for detection.

[0035] 3、The application adopts the whole system flow scheme, provides state reproduction and three-dimensional visualization monitoring on the basis of simulation, and facilitates subsequent statistical analysis on the collision condition.

[0036] 4、The path planning of the robot tool changing is fully simulated and verified, the optimal motion path result is output for the robot, and the safety and efficiency in the robot tool changing process are improved. ACCURACY

[0037] In order to better describe the purpose and scheme of the application, the application will be described in detail below according to the drawings:

[0038] Fig. 1 is a method implementation flowchart of the application;

[0039] Fig. 2 is a trajectory planning algorithm schematic diagram of the application;

[0040] Fig. 3 is a collision detection method schematic diagram of the application;

[0041] Fig. 4 is a data storage flowchart schematic diagram of the application. DETAILED DESCRIPTION

[0042] The application will be described in detail below in combination with the drawings and specific embodiments. The embodiment is implemented on the premise of the technical scheme of the application, and gives a detailed implementation manner and specific operation process, but the protection scope of the application is not limited to the following embodiments.

[0043] The application provides a virtual simulation platform verification method for tool changing of a shield machine, which can fully verify the motion trajectory of the robot when the robot performs tool changing of the shield machine, output an optimal path result, so as to simulate the tool changing process of the mechanical arm, and improve the safety and operation efficiency of the robot tool changing.

[0044] As shown in Fig. 1 to Fig. 4, the virtual simulation platform verification method for tool changing of a shield machine provided by the application is mainly realized through the following flow:

[0045] 1. Motion simulation: let the user design the initial and final poses of the robot in the virtual environment, complete the path planning of the robot, verify the safety of the path before the actual work of the robot, and use the collision detection technology to find the collision points in the path in advance.

[0046] 2. Three-dimensional visualization monitoring: the running state of the robot is monitored and three-dimensionally displayed, and these states include the speed, acceleration and angle of each axis of the robot.

[0047] 3. Running state reproduction: the running data of the robot is stored, and the user can reproduce the running state by inputting the historical time node.

[0048] The specific implementation steps are as follows:

[0049] S1: First, develop a system interface based on the Unity3D platform, the interface includes a monitoring start panel, a running state reproduction panel, a motion simulation panel, and a data display panel, and all corresponding requirements can be intuitively displayed through the interface;

[0050] S2: Import the model of the corresponding shield machine automatic tool changer robot and tool space pose simulation mechanism into the Unity software, and establish a full-scale environmental model corresponding to the actual object and space layout in the virtual platform;

[0051] S21: Control the joints of the robot in the virtual environment, input the corresponding rotation angle of each joint through the virtual simulation platform, and make the mechanical arm move to the specified position, so as to design the teaching point for the robot twin model;

[0052] S22: Select the mode of trajectory planning, including joint planning, straight line planning, and circular arc planning, according to the teaching point designed by the user, use the forward and inverse kinematics of the robot and the trajectory planning algorithm to plan the trajectory of the robot, and get the planning sequence, wherein the trajectory planning algorithm is written in the form of script in Unity3D, and the related functions in Unity3D are used for interpolation to realize the motion. Joint space interpolation is achieved by using Mathf.Lerp(from:float,to:float,time:float), which returns a floating-point number. Straight line interpolation is achieved by using Vector3.Lerp(from:Vector3,to:Vector3,timer:float), which returns a three-dimensional vector. By changing the value of time in each frame of animation, that is, in the Update() method, the return value is changed, and then the rotation angle of each joint is changed to form a continuous animation; as shown in FIG. 2, which is a joint interpolation method.

[0053] S23: Motion simulation analysis and collision detection, use the virtual environment to simulate the motion of the planning result, and call the collision detection algorithm in the simulation process;

[0054] S24: As shown in FIG. 3, if a collision is detected during simulation, a collision prompt is given, and collision detection is mainly achieved through the technology based on the bounding box,

[0055] First, the AABB bounding box of the detection object is calculated as the root node of the tree;

[0056] Secondly, find the longest axis of the bounding box, and take the midpoint of the axis as the split point. Then, make a plane perpendicular to the split axis through the split point, which is the split plane. According to the split plane, the triangular patches of the model are divided into two subsets. For the triangular patches on the split plane, they are divided into the subset with less triangular patches.

[0057] Finally, build the bounding box for the divided subsets as the left and right child nodes of the parent node, and repeat the second and third steps.

[0058] S25: Track the end trajectory, visually display the motion trajectory, output the planning result, control the physical entity, and then import the result into the controller to control the motion of the physical robot;

[0059] S3: Establish a virtual system using the Unity3D platform, map the twin data to the virtual system, synchronize the virtual system and the physical entity, make the three-dimensional model in the virtual system and the real device run synchronously, display and store the device running information, update the model attributes in each frame through C# logic layer script control, make the model follow the real device to run synchronously, and display the current device running data. The monitoring data includes the control value of each axis, the motor operation mode, the actual position of the motor, the joint angle, the joint speed, the joint acceleration, and the joint torque.

[0060] S4: As shown in FIG. 4, for the data transmitted by the server side (robot controller), on the one hand, it is mapped to the model as real-time data to drive the model motion, and on the other hand, it is stored in the database as the data source for querying the historical working state. The system adopts C / S (Client / Server) architecture, which is composed of client and server. The robot controller is the server side, and the simulation monitoring system established by Unity3D is the client side. Socket is used to realize the communication between the server side and the client side.

[0061] MySQL database is selected as the data storage platform, and MySQL plug-in is loaded in Unity3D. The database operation class SQL class is developed to encapsulate the connection, closing, adding, deleting, modifying, and querying operations of the database as methods to improve code reusability, facilitate database operation, and improve development efficiency.

[0062] In summary, the automatic tool changing robot motion simulation and state monitoring system based on the Unity game engine can realize real-time visual monitoring of the tool changing robot, improve the safety of the tool changing robot operation, and verify the robot trajectory planning and motion simulation in the virtual system. A database is constructed for the virtual environment data to store the key operating parameters of the robot, reproduce the operating state of the robot, and perform data analysis and data mining in the future to improve the operating efficiency of the robot.

[0063] The above-described embodiments only express one implementation of the present application, which is described in a more specific and detailed manner, but should not be understood as a limitation to the scope of the patent. It should be noted that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of protection of the present application. Therefore, the scope of protection of the patent of the present application should be subject to the appended claims.

Claims

1. A virtual simulation platform verification method for a shield machine tool changing, characterized in that, The implementation is achieved through the following process: Motion simulation: let the user design the robot starting and ending pose in the virtual environment, complete the robot path planning, check the safety of the path before the robot actually works, and use collision detection technology to find collision points in the path in advance; Three-dimensional visualization monitoring: monitor and three-dimensionally display the running state of the robot, including the speed, acceleration and angle of each axis of the robot; Running state reproduction: store the robot running data, and reproduce the running state by inputting the historical time node; The specific implementation steps are as follows: Step S1: first, develop a system based on a virtual simulation platform, and all corresponding requirements can be intuitively displayed and operated through the interface; Step S2: import the model of the corresponding shield machine automatic tool changer robot and tool space pose simulation mechanism into the virtual simulation platform, and establish a proportional environment model in the virtual platform that completely corresponds to the actual object and space layout; Step S21: control the joints of the robot in the virtual environment, input the corresponding rotation angle of each joint through the virtual simulation platform, and make the mechanical arm move to the specified position to design the teaching point for the robot twin model; Step S22: select the mode of trajectory planning, use the forward and inverse kinematics of the robot and the trajectory planning algorithm to plan the trajectory of the robot according to the teaching points designed by the user, and obtain the planning sequence, wherein the trajectory planning algorithm is written in the form of a script in the virtual simulation platform, and the related functions in the virtual simulation platform are used for interpolation to realize motion; Step S23: motion simulation analysis and collision detection, use the virtual environment to simulate the motion of the planning result, and call the collision detection algorithm during the simulation process; Step S24: if a collision is detected during the simulation process, a collision prompt is given, and the collision detection is realized through the technology based on the bounding box; Step S25: track the end trajectory, intuitively display the motion trajectory, output the planning result, control the physical entity, and then import the result into the controller to control the motion of the physical robot; Step S3: use the virtual simulation platform to establish a virtual system, map the twin data to the virtual system, realize the synchronization of the virtual system and the physical entity, make the three-dimensional model in the virtual system and the real device run synchronously, display and store the device running information, and update the model attributes in each frame through the control of the logic layer script, so that the model follows the real device to move synchronously, and the current device running data is displayed; Step S4: for the data transmitted by the server side, on the one hand, it is mapped to the model as real-time data to drive the model motion, and on the other hand, it is stored in the database as the data source for querying the historical working state; the system adopts C / S architecture, that is, it is composed of a client and a server, the robot controller is the server, and the simulation monitoring system established by the virtual simulation platform is the client; the communication between the server and the client is realized by using Socket; Select a database as the data storage platform, load the database plug-in in the virtual simulation platform, develop the database operation class SQL class, and encapsulate the connection, closing, adding, deleting, modifying and querying operations of the database as methods.

2. The method of claim 1, wherein, The virtual simulation platform is Unity3D software.

3. The method of claim 1, wherein, The database is a MySQL database.

4. The method of claim 1, wherein, In step S1, the interface includes a monitoring start panel, a running state reproduction panel, a motion simulation panel and a data display panel.

5. The method of claim 1, wherein, In step S22, the trajectory planning algorithm is written in the virtual simulation platform in the form of a script, and interpolation is performed by using relevant functions in the virtual simulation platform to realize motion; wherein, joint space interpolation is implemented by using Mathf.Lerp, and the return value is a floating point number; straight line interpolation is implemented by using Vector3.Lerp, and the return value is a three-dimensional vector; by changing the value of time in each frame of animation, that is, in the Update() method, the return value is changed, and then the joint rotation angle is changed to form a continuous animation.

6. The method of claim 1, wherein, In step S22, the trajectory planning mode includes joint planning, straight line planning and circular arc planning.

7. The method of claim 1, wherein, In step S24, collision detection is implemented by using a bounding box-based technology, and specifically: In step S241, the AABB bounding box of the detection object is calculated as the root node of the tree; In step S242, the longest axis of the bounding box is found, and the midpoint of the axis is taken as the split point, a plane perpendicular to the split axis is made through the split point, that is, the split plane, and the triangular patches of the model are divided into two subsets according to the split plane, and the triangular patches located on the split plane are divided into the collection with fewer triangular patches; In step S243, the bounding box is constructed for the divided collection as the left and right child nodes of the parent node, and the process of step S242 and step S243 is repeated.

8. The method of claim 1, wherein, In step S3, the monitoring data includes the control value of each axis, the motor operation mode, the actual position of the motor, the joint angle, the joint speed, the joint acceleration and the joint torque.

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