Digital Twin System and Method for a Joint Robot

Abstract

This paper proposes a digital twin method and system based on articulated robots, including an articulated robot basic entity system, a physical twin system, an articulated robot virtual simulation system, a historical database, and a sensor data acquisition and processing module. In this system, its virtual simulation system is independent of the physical system. By using the data set generated by the movement of the physical object, the kinematic model of the articulated robot is optimized to construct a high-fidelity virtual simulation system. The virtual system serves as the core in the data transmission framework and is connected to the historical database, the robot basic entity system, and the sensor data acquisition and processing module respectively. This digital twin system integrates real-time mapping, historical mapping, remote control, virtual simulation, and virtual monitoring, and has powerful functions.

Description

Technical Field

[0001] The present invention relates to the field of operating state monitoring and remote control of articulated robots, and particularly to a digital twin system and method for an articulated robot. Background Art

[0002] With the widespread application of sensor technology, a large amount of data in daily life and production equipment has been recorded, laying a foundation for digital and informatization research. At the same time, digital twin technology has also been widely studied and applied at home and abroad. Digital twin relies on the data information of a physical entity to construct a digital virtual model of the physical entity, and uses the high fidelity of the dynamic characteristics of the physical entity and the virtual model. Through the behavior and data of the physical data and the virtual space generated by the virtual model, combined with data analysis, decision optimization and other methods, functions such as equipment control, model optimization, fault diagnosis and behavior prediction are completed.

[0003] At present, the digital twin technology of articulated robots is mainly applied to data monitoring of articulated robots and visualization of three-dimensional models, but the construction of the surrounding environment is lacking, and the relative position relationship between the robot and the surrounding environment is not reflected. In addition, compared with the physical system, its simulation system lacks certain measures for the fidelity of the DH parameters and the joint motion function of the simulation system, resulting in a large difference in information between the virtual system and the physical system. Summary of the Invention

[0004] The present invention discloses a digital twin method and system for an articulated robot, which can realize functions such as real-time mapping, historical mapping, virtual simulation, remote control and virtual monitoring, facilitating decision-making and remote management by managers; at the same time, the least squares method is used in this paper to solve the robot kinematics optimization model and the joint angle motion function is corrected with actual data, further ensuring the consistency between the virtual model and the physical model, making the measured values in the virtual space meaningful, facilitating data measurement by managers and more detailed operations.

[0005] To solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A digital twin system for an articulated robot, characterized by comprising: an articulated robot basic entity system, a physical twin system, an articulated robot virtual simulation system, a historical database, and a sensor data acquisition and processing module;

[0007] Among them, the basic entity system of the articulated robot includes a robot mechanical entity, a control system for the robot mechanical entity, and an application interface for the robot mechanical entity. The control system for the robot mechanical entity drives the robot mechanical entity, and the mechanical entity application interface is connected to the control system for the robot mechanical entity to reflect the parameters of the control system for the robot mechanical entity;

[0008] The physical twin system is used to connect the basic entity system of the articulated robot and the simulation system of the articulated robot and realize real-time mapping between the basic entity system of the articulated robot and the simulation system of the articulated robot;

[0009] The virtual simulation system of the articulated robot includes a 3D model of the articulated robot, a virtual controller, and a virtual application interface. The virtual simulation system of the articulated robot integrates virtual simulation and data driving, and can perform simulation motion independently of the physical twin system;

[0010] The historical database stores the historical data of the operation of the physical twin system;

[0011] The sensor data acquisition and processing module acquires sensor message data and decodes it into required data, serving as an intermediate processing module.

[0012] Furthermore, the mechanical entity application interface includes a data monitoring interface, a parameter setting interface, and a motion control interface;

[0013] The data monitoring interface displays the values of each processed data for monitoring the current state of the robot mechanical entity;

[0014] The parameter setting interface sets the motion speed and motion mode of the robot mechanical entity;

[0015] The motion control interface enables the robot to move according to joint angles and inverse-solve motions based on coordinate points and end states.

[0016] Furthermore, the data input into the historical database includes the data processed by the sensor data acquisition and processing module and the time when the data is acquired, and is written into the historical database from top to bottom in time series. The external accesses it with time as the primary key for historical data driving, so as to achieve the function of scene reproduction.

[0017] Furthermore, the virtual simulation system includes a 3D model of the articulated robot, a virtual application interface, and a virtual controller;

[0018] The 3D model of the articulated robot includes a robot entity model and the surrounding obstacle environment. A 1:1 sub-assembly model is established according to the optimized kinematic model DH parameters and the dimensions of the robot entity, and it is correctly assembled to ensure the correctness of the robot DH parameters and the relative position between the robot and the environment. Rendering is performed to assign materials, and the parent-child object relationship of each joint of the articulated robot is established to simplify the joint movement;

[0019] The virtual controller corrects the model based on the joint angle path planning motion function model adopted by the physical twin system and uses the data in the historical database. It drives each joint through interpolation at different times using a fixed-time refresh function to achieve the purpose of simulation motion;

[0020] The virtual application interface includes a virtual human-machine interaction interface, a virtual data monitoring interface, and a virtual historical data reading interface.

[0021] Further, among them,

[0022] The virtual human-machine interaction interface controls the robot to move according to joint motion and point-to-point motion, and inserts the inverse kinematics algorithm of the robot;

[0023] The virtual data monitoring interface monitors joint angle data, the position and attitude of the end effector, collision warning information, running time, and is equipped with a virtual camera to provide a basis for decision-making and debugging for remote control;

[0024] The virtual historical data reading interface searches in the historical database according to the input time period and reads according to the time interval to achieve the purpose of scene reproduction.

[0025] Further, the digital twin system of the articulated robot takes the articulated robot simulation system as the core, and establishes a data connection between the basic entity system of the articulated robot, the physical twin system, the virtual simulation system of the articulated robot, the historical database, and the sensor data acquisition and processing module through data lines and computer IO ports.

[0026] Further, the virtual data monitoring interface arranges a virtual camera in space to monitor the 3D model of the articulated robot, reasonably parameterizes the sizes of the components in the surrounding environment, obtains information about the robot link components that are about to collide within the set distance in the virtual space, and gives early warnings to assist in decision-making; monitors the position and attitude of the end effector of the virtual robot, obtains the coordinate points of the object coordinates in the world coordinate system, the vector directions of the y, z, and x axes, and correctly configures the parent-child objects. Through the conversion of the rotation matrix, the position and attitude information of the end effector can be obtained. Establishing an optimized kinematic model to obtain optimized DH parameters is a prerequisite for virtual monitoring to be realized.

[0027] The present invention also provides a digital twin method for a joint robot, which is characterized by including the following steps:

[0028] Step 1: Based on the robot DH parameters provided by the manufacturer, establish a kinematic mathematical model of the joint robot before correction;

[0029] Step 2: Based on the joint robot encoder, collect joint angle message data and decode it into normal joint angle data, bind the time of the collected data for data transmission;

[0030] Step 3: Based on the laser tracker measurement, obtain the coordinates of the end effector of the joint robot, and combine the joint angle data in Step 2 to collect the joint angle - end effector coordinate data pairs;

[0031] Step 4: Establish an optimized kinematic model of the robot to derive an optimized 3D virtual model of the joint robot;

[0032] Step 5: Based on the optimized 3D virtual model of the joint robot and the processed joint angle data, perform three - dimensional dynamic visualization display on the robot motion entity and the surrounding environment;

[0033] Step 6: Based on the historical data after driving, construct a historical database structure, store the historical data in time series, and provide a basis for historical data driving;

[0034] Step 7: Based on the historical database, analyze the historical data to obtain a robot joint angle motion model, which provides a basis for robot simulation motion;

[0035] Step 6: Based on the 3D virtual model of the joint robot, perform virtual monitoring and remote control on the mechanical state of the robot. Through the joint angles, end effector position and orientation, collision warning information, and the state of the three - dimensional model from multiple perspectives shown in the virtual system, it helps the operator make better decisions and perform equipment debugging.

[0036] Further, the optimized kinematic model of the robot is to construct an initial kinematic model through the robot DH parameters provided by the manufacturer, combine the errors of the robot link length and link offset, use the data set of the collected joint angle - end effector coordinate data pairs, and use the least - squares method to iteratively obtain the optimal DH parameters multiple times, thereby establishing an optimized kinematic model.

[0037] Further, it is characterized in that the joint angle motion model is obtained by correcting the joint angle control track planning model adopted by the actual robot system using the time - joint angle data in the historical database.

[0038] Compared with the prior art, the present invention has at least the following beneficial effects:

[0039] Through the calibration of the kinematic model of the robot based on the data measured by the basic entity system of the robot, the consistency of the DH parameters of the virtual model and the physical model is guaranteed to a great extent, thus ensuring the correctness of the position and posture of the robot end effector obtained from the virtual space and the inverse kinematics solution of the robot, providing a more reliable basis for remote control and decision-making; the data transmission framework of the present invention takes the virtual simulation system as the core of the framework, reduces the intermediate data transmission link of virtual-real mapping, that is, reduces the real-time mapping cycle of data, and improves the real-time performance of the digital twin system; the digital twin system is powerful in function, integrating real-time mapping, historical mapping, remote control, virtual simulation and virtual monitoring; based on the good fidelity of the system, virtual monitoring makes full use of the characteristics of the virtual space, such as collision detection, virtual cameras, and the coordinate points and posture information of the end effector are easy to extract, providing more information for digital monitoring and decision-making. Description of the Drawings

[0040] Figure 1 It is the composition and information flow chart of the digital twin system of the present invention;

[0041] Figure 2 It is the method flow chart of the present invention. Detailed Embodiments

[0042] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0043] It should be noted that the experimental methods described in the following implementation schemes are all conventional methods unless otherwise specified, and the reagents and materials can be obtained from commercial channels unless otherwise specified; in the description of the present invention, the terms "horizontal", "longitudinal", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.

[0044] In addition, terms such as "horizontal", "vertical", "overhanging" do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0045] In the description of the present application, it should also be noted that unless otherwise clearly specified and defined, the terms "set", "installed", "connected", and "linked" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0046] As Figure 1 shown, this embodiment provides a digital twin system for a joint robot, including: a joint robot basic entity system, a physical twin system, a joint robot virtual simulation system, a historical database, and a sensor data acquisition and processing module;

[0047] Among them, the joint robot basic entity system includes a robot mechanical entity, a robot mechanical entity control system, and a robot mechanical entity application interface, and the robot mechanical entity control drives the robot mechanical entity;

[0048] The physical twin system is used to connect the joint robot basic entity system and the joint robot simulation system and realize the real-time mapping between the joint robot basic entity system and the joint robot simulation system;

[0049] The joint robot virtual simulation system includes a joint robot 3D model, a virtual controller, and a virtual application interface. The joint robot virtual simulation system integrates virtual simulation and data driving, and can perform simulation movements independently of the physical twin system; in this embodiment, the joint robot virtual simulation system is developed using Unity3D;

[0050] The historical database stores the historical data of the operation of the physical twin system;

[0051] The sensor data acquisition and processing module collects sensor message data and decodes it into the required data, serving as an intermediate processing module.

[0052] In a further preferred embodiment, the mechanical entity application interface includes a data monitoring interface, a parameter setting interface, and a motion control interface;

[0053] The data monitoring interface displays the values of each data after acquisition and processing, and is used to monitor the current state of the robot mechanical entity;

[0054] The parameter setting interface sets the motion rate and motion mode of the robot mechanical entity, including the motion function of the trajectory planning of each joint;

[0055] A motion control interface enables the robot to move according to joint angles and perform inverse kinematic motion based on coordinate points and end - effector states.

[0056] Further, the data input into the historical database includes the data processed by the sensor data acquisition and processing module and the time when the data is acquired. The time of data acquisition is accurate to milliseconds and is written into the historical database from top to bottom in time series. Externally, access is made using time as the primary key for historical data - driven operation, thus achieving the function of scenario reproduction.

[0057] Further, the virtual simulation system includes a robotic arm 3D model, a virtual application interface, and a virtual controller.

[0058] The robotic arm 3D model includes a robot entity model and a surrounding obstacle environment. A 1:1 sub - assembly model is established according to the optimized kinematic model DH parameters and the dimensions of the robot entity, and correct assembly is ensured to guarantee the correctness of the robot DH parameters and the relative position between the robot and the environment. Materials are rendered and assigned, and the parent - child object relationships of each joint of the robotic arm are established to simplify joint motion.

[0059] The virtual controller, based on the joint - angle path - planning motion function model adopted by the physical twin system, uses the data in the historical database to correct the model. Using a fixed - time refresh function, interpolation is performed based on positions at different times to drive each joint, so as to achieve the purpose of simulation motion. The virtual controller is mainly used to simulate the motion of a real robot and implement the control functions of each virtual interface. In this embodiment, the virtual controller is a script written using Unity3D. Using the robotic arm joint - angle motion function provided by the manufacturer, and through the fitting curve of historical data, correction compensation parameters are obtained, thus obtaining a function close to the actual robotic arm joint - angle motion function. Utilizing the characteristic of the FixedUpdate function in Unity3D to refresh at fixed time intervals and the rotate rotation motion function, interpolation motion is performed according to the motion function. The time interval is very small, thus realizing three - dimensional dynamic simulation motion. A button control click - trigger event function is written to enable changing the internal operating program of the virtual system and inputting interface data through the button. A Socket server program is written, and a data interface is reserved for receiving data and reading database data.

[0060] The virtual application interface includes a human - machine interaction interface, a virtual data monitoring interface, and a historical data reading interface.

[0061] Further, in the human-computer interaction interface, the robot is controlled to move according to joint movement and point-to-point movement (insert the inverse kinematics algorithm of the robot). The same interaction interface is used for remote control and virtual simulation, and the mode is switched through button controls. (2) Virtual data monitoring interface, which monitors joint angle data, end effector position and attitude, collision warning information, running time, virtual camera, etc., providing a basis for decision-making and debugging in remote control. (3) Historical data reading interface, which switches to the corresponding mode through buttons, searches in the historical database according to the input time period, and reads according to the time interval to achieve the purpose of scene reproduction.

[0062] In the above embodiment, the virtual application interface design of the present invention means integrating functions of real-time mapping, historical mapping, virtual simulation, virtual monitoring, and remote control. To meet the above functions, the required interfaces include a human-computer interaction interface, a virtual data monitoring interface, and a historical data reading interface. The UI controls and scripts in Unity3D are used to implement the interface design that combines static and dynamic elements. Considering the immutability of the human-computer interaction interface and the monitoring interface, static UI controls are used to draw their interfaces, and the historical data reading interface is drawn dynamically with scripts.

[0063] The human-computer interaction interface is mainly used to send instructions to the robot, enabling the robot to move according to joint angles and points, setting the running speed of the robot, emergency stop, and cyclic program movement, etc. The same human-computer interaction interface is used for remote control and virtual simulation, and the switch is made through button controls.

[0064] The virtual data monitoring interface displays the angles of each joint, running time, position and attitude of the end effector, data connection status, collision warning information, the mode of the system (real-time data-driven, historical data-driven or virtual simulation), and the two-dimensional virtual camera screen. The joint angles and running time are displayed through the joint angles and time collected by the actual robot. The position and attitude of the end effector can be easily obtained by using the transform component and corresponding attributes in Unity3D. The collision warning information is obtained by reasonably setting the dimensions of the corresponding components in the surrounding environment using the Collider component in Unity3D, that is, the information about the part of the robot model that is about to collide within its dimensions can be obtained and then displayed on the monitoring interface. A virtual camera is arranged in advance in Unity3D using the camera component, and scripts are written to switch the screens of different cameras through buttons, which has a certain significance for simulating real camera monitoring.

[0065] The historical data reading interface is used for reproducing historical scenarios. Static button controls are set. Clicking on the button controls can run the corresponding scripts to draw this interface. By inputting the start and end times of the time period, the data in the historical database is read sequentially at time intervals for driving, achieving the purpose of reproducing historical scenarios.

[0066] Furthermore, the digital twin system of the articulated robot takes the articulated robot simulation system as the core. Through data lines and computer IO ports, data connections are established among the articulated robot basic entity system, the physical twin system, the articulated robot virtual simulation system, the historical database, and the sensor data acquisition and processing module. The connection method between the sensor data acquisition and processing module and the robot entity system is not limited, such as serial port or embedding, etc. Socket communication is carried out between the sensor data acquisition and processing module and the virtual simulation system. The processed joint angle data and acquisition time are transmitted to the virtual system through Socket communication. The virtual system uses this data to drive the 3D model to move. After the driving is completed, the data is stored in the local database according to the time sequence through the computer port number. The database structure includes joint angle information and time information accurate to ms. When reading historical data, the data in the local database is also read using the computer port number. The virtual system is connected to the physical entity of the robot through Socket communication, and motion instructions are transmitted according to the human-computer interaction of the virtual interface, realizing the function of remote control.

[0067] Furthermore, the virtual data monitoring interface arranges virtual cameras in space to monitor the 3D model of the articulated robot, reasonably parameterizes the sizes of the components in the surrounding environment, obtains partial information of the robot that is about to collide within the set distance in the virtual space, and gives early warnings for auxiliary decision-making; monitors the position and posture of the end effector. Using the position, up, forward, and right in the transform component of Unity3D, the coordinate points of the object coordinates in the world coordinate system and the vector directions of the y, z, and x axes can be obtained respectively. By correctly configuring the parent and child objects through the conversion of the rotation matrix, the position and posture information of the end effector can be obtained. Establishing an optimized kinematic model to obtain optimized DH parameters is the prerequisite for virtual monitoring to be realized.

[0068] As Figure 2 shown, the present invention also provides a digital twin method for an articulated robot, which is characterized by including the following steps:

[0069] Step 1: Based on the robot DH parameters provided by the manufacturer, establish a kinematic mathematical model of the articulated robot before correction;

[0070] Step 2: Based on the joint angle message data collected by the articulated robot encoder, decode it into normal joint angle data, and bind the time of the collected data for data transmission;

[0071] Step 3: Measure based on a laser tracker to obtain the coordinates of the end effector of the articulated robot, and collect the joint angle-end effector coordinate data pairs by combining the joint angle data in Step 2;

[0072] Step 4: Establish an optimized kinematic model of the robot to derive an optimized 3D virtual model of the articulated robot;

[0073] Step 5: Based on the optimized 3D virtual model of the articulated robot and the processed joint angle data, perform three-dimensional dynamic visualization display of the robot's moving entity and the surrounding environment;

[0074] Step 6: Based on the historical data after driving, construct the historical database structure, store the historical data in time series, and provide a basis for historical data driving;

[0075] Step 7: Analyze the historical data based on the historical database to obtain the robot joint angle motion model, which provides a basis for the robot simulation motion;

[0076] Step 6: Based on the 3D virtual model of the articulated robot, perform virtual monitoring and remote control of the mechanical entity state of the robot. By monitoring the virtual mapping of the joint angles, the position and orientation of the end effector, the collision warning information, and the state of multiple perspectives of the 3D model, it helps the operator make better decisions and perform equipment debugging.

[0077] Further, in Step 4, the optimized kinematic model of the robot is to construct an initial kinematic model through the DH parameters of the robot provided by the manufacturer, combine the errors of the robot link lengths and link offsets, use the data set of the collected joint angle-end effector coordinate data pairs, and use the least squares method to iteratively obtain the optimal DH parameters multiple times, thereby establishing an optimized kinematic model. In this embodiment, since the parameters provided by the manufacturer are theoretical values, calibration is still required to obtain accurate values. Use a laser tracker to measure and obtain the data set of the joint-end effector coordinates of the articulated robot. Usually, the encoder discs of the articulated robot do not make mistakes, and the included angle between its links is brought in with actual measurements, so its main error comes from the length a of the link i and the deviation value d of the link i . Assuming there are n links, the following can be obtained at this time

[0078]

[0079] Among them, P x , P y , P z respectively represent the coordinates of the end effector in the X, Y, and Z directions; f x , f y , fz is an equation established through the robot kinematic model, with the end-effector X, Y, and Z coordinates as the dependent variables, and a i , d i as the independent variables. a i , represents the length of the i-th link, and d i represents the deviation between the i-th link and the i-1-th link. P x , P y , P z The differential form can be obtained as follows:

[0080]

[0081]

[0082]

[0083] are the error values of the end-effector coordinates, obtained by taking the difference between the true values measured by the laser tracker and the coordinate values solved from the joint angles through the kinematic mathematical model before correction. In the above formula, f x , f y , f z The functions are all known and are equality models established based on the kinematic model. Thus, that is, the error value of the offset between links can be solved. Then, it is compensated into the DH parameters corresponding to the kinematic mathematical model before correction, and the above method is continuously iterated until the error reaches the set expectation. At this time, the optimized kinematic model is obtained.

[0084] In a further optimized embodiment, for the DH parameters of the optimized kinematic model and the dimensions of the robot entity, the robot is divided into multiple assembled sub-objects with each joint as a node. SolidWorks is used to parametrically model each sub-part of the robot at a 1:1 ratio, and then they are assembled together. The installation gaps are correctly allocated to ensure that the DH parameters of the 3D robot model are consistent with the optimized model. The static environment around the robot is modeled, and the relative position relationship between the robot and the environment is correctly configured. The built model is imported into 3Dmax for rendering and material assignment to enhance its authenticity. And its unit (to prevent the model from changing in size), joint angles, and the parent-child object relationship between links are correctly configured. Finally, the FBX file is exported and imported into Unity3D, and the 3D modeling process ends.

[0085] Furthermore, the joint angle motion model is obtained by correcting the joint angle control trajectory planning model adopted by the actual robot system using the time-joint angle data in the historical database.

[0086] The embodiments described above are only descriptions of the preferred embodiments of the present invention, and do not limit the concept and scope of the present invention. Without departing from the design concept of the present invention, various variations and improvements made by those of ordinary skill in the art to the technical solution of the present invention shall fall within the protection scope of the present invention. The technical content for which the present invention requests protection has been fully recorded in the claims.

Claims

1. A digital twin system for a joint robot, characterized in that Including: An articulated robot basic entity system, a physical twin system, an articulated robot virtual simulation system, a historical database, and a sensor data acquisition and processing module; Among them, the articulated robot basic entity system includes a robot mechanical entity, a robot mechanical entity control system, and a robot mechanical entity application interface. The robot mechanical entity control system drives the robot mechanical entity, and the mechanical entity application interface connects to the robot mechanical entity control system to reflect the parameters of the robot mechanical entity control system; The physical twin system is used to connect the articulated robot basic entity system and the articulated robot simulation system and realize real-time mapping between the articulated robot basic entity system and the articulated robot simulation system; The articulated robot virtual simulation system includes an articulated robot 3D model, a virtual controller, and a virtual application interface. The articulated robot virtual simulation system integrates virtual simulation and data driving, and can perform simulation movements independently of the physical twin system; The virtual simulation system includes an articulated robot 3D model, a virtual application interface, and a virtual controller; The articulated robot 3D model includes a robot entity model and a surrounding obstacle environment. A 1:1 sub-assembly model is established according to the optimized kinematic model DH parameters and the dimensions of the robot entity, and correctly assembled to ensure the correctness of the robot DH parameters and the relative position between the robot and the environment. Render and assign materials, and establish the parent-child object relationship of each joint of the articulated robot to simplify the joint movement; The virtual controller, based on the joint angle path planning motion function model adopted by the physical twin system, uses the data in the historical database to correct the model, and uses a fixed-time refresh function to drive each joint through interpolation at different times to achieve the purpose of simulation movement; The virtual application interface includes a virtual human-computer interaction interface, a virtual data monitoring interface, and a virtual historical data reading interface; The virtual human-computer interaction interface controls the robot to move according to joint movement and point-to-point movement, and inserts the inverse kinematics algorithm of the robot; The virtual data monitoring interface monitors joint angle data, end effector position and attitude, collision warning information, running time, and is equipped with a virtual camera to provide a decision-making and debugging basis for remote control; The virtual historical data reading interface searches in the historical database according to the input time period and reads according to the time interval to achieve the purpose of scene reproduction; The historical database stores the historical data of the operation of the physical twin system; The sensor data acquisition and processing module acquires sensor message data and decodes it into the required data, serving as an intermediate processing module.

2. The digital twin system of the articulated robot according to claim 1, characterized in that The mechanical entity application interface includes a data monitoring interface, a parameter setting interface, and a motion control interface; The data monitoring interface displays the values of each processed data for monitoring the current state of the robot mechanical entity; The parameter setting interface sets the motion speed and motion mode of the robot mechanical entity; The motion control interface enables the robot to move according to joint angles and inverse-solve the motion according to coordinate points and end states.

3. The digital twin system of the articulated robot according to claim 1, wherein The data input into the historical database includes the data processed by the sensor data acquisition and processing module and the time when the data is collected, and is written into the historical database one by one from top to bottom according to the time series. The external accesses it with time as the primary key to perform historical data driving, so as to achieve the function of scenario reproduction.

4. The digital twin system of the articulated robot according to claim 1, wherein The articulated robot digital twin system takes the articulated robot simulation system as the core, and establishes data connections among the articulated robot basic entity system, the physical twin system, the articulated robot virtual simulation system, the historical database, and the sensor data acquisition and processing module through data lines and computer IO ports.

5. The digital twin system of the articulated robot according to claim 1, wherein, The virtual data monitoring interface arranges virtual cameras in space to monitor the 3D model of the articulated robot, reasonably parameterizes the sizes of the components in the surrounding environment, and obtains the information of the robot link components that are about to collide within the set distance in the virtual space to provide early warning and auxiliary decision-making. By monitoring the position and posture of the end effector of the virtual robot, the coordinate points of the object coordinates in the world coordinate system and the vector directions of the y, z, and x axes can be obtained. By correctly configuring the parent and child objects through the conversion of the rotation matrix, the position and posture information of the end effector can be obtained. Establishing an optimized kinematic model to obtain the optimized DH parameters is the prerequisite for virtual monitoring.

6. The digital twin method of the articulated robot of the articulated robot digital twin system according to any one of claims 1-5, characterized in that It includes the following steps: Step 1: Based on the DH parameters of the robot provided by the manufacturer, establish the kinematic mathematical model of the articulated robot before correction. Step 2: Based on the articulated robot encoder, collect joint angle message data and decode it into normal joint angle data, and bind the time of the collected data for data transmission. Step 3: Based on the laser tracker measurement, obtain the coordinates of the end effector of the articulated robot, and combine the joint angle data in Step 2 to collect the joint angle-end effector coordinate data pairs. Step 4: Establish an optimized kinematic model of the robot to derive the optimized 3D virtual model of the articulated robot. Step 5: Based on the optimized 3D virtual model of the articulated robot and the processed joint angle data, perform three-dimensional dynamic visualization display of the robot motion entity and the surrounding environment. Step 6: Based on the historical data after driving, construct the historical database structure, store the historical data according to the time series, and provide a basis for historical data driving. Step 7: Based on the historical database, analyze the historical data to obtain the robot joint angle motion model, which provides a basis for the robot simulation motion. Step 8: Based on the 3D virtual model of the articulated robot, perform virtual monitoring and remote control of the robot mechanical state. Through the joint angles, end effector position and direction, collision warning information, and multi-view state of the three-dimensional model shown in the virtual system, it helps the operator make better decisions and perform equipment debugging.

7. A digital twin method for a joint robot according to claim 6, characterized in that, In Step 4, the optimized kinematic model of the robot is constructed by using the DH parameters of the robot provided by the manufacturer to establish an initial kinematic model, combining the errors of the robot link length and link offset, and using the dataset of the collected joint angle-end effector coordinate data pairs. The optimal DH parameters are obtained through multiple iterations using the least squares method, thereby establishing an optimized kinematic model.

8. A digital twin method for a joint robot according to claim 6, characterized in that, The joint angle motion model is obtained by correcting the joint angle control trajectory planning model adopted by the actual robot system using the time-joint angle data in the historical database.

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