A simulation method, system and device for dynamic characteristics of a linear servo joint and a medium

Abstract

This invention provides a simulation method, system, device, and medium for the dynamic characteristics of linear servo joints. The method embeds a transmission chain considering nonlinear factors into the initial electromechanical coupling system-level model, resulting in an optimized electromechanical coupling system-level model. The transmission chain considering nonlinear factors includes a transmission clearance model, a friction model, and / or a stiffness model. This solves the problem of treating the transmission chain as an ideal system in existing co-simulation methods, and can realistically reflect the actual dynamic behavior of the joint under the influence of nonlinear factors. A software interface is constructed based on the GSE state equation module of the dynamic simulation software ADAMS and the interface module of the multi-domain system modeling and simulation software AMESim. Real-time data transmission of the transmission parameters is performed based on the software interface, realizing the collaborative solution of the multibody dynamics model and the optimized electromechanical coupling system-level model. This method can accurately describe the mechanical dynamic characteristics of the joint and finely characterize the electromechanical coupling process of the servo motor-control-transmission chain.

Description

Technical Field

[0001] This invention belongs to the field of robot joint simulation technology, specifically relating to a simulation method, system, device, and medium for the dynamic characteristics of a linear servo joint. Background Technology

[0002] Linear servo joints are core drive components in the robotics field. Through a highly integrated design of servo motors, transmission mechanisms, and detection sensors, they can directly output high-precision linear motion, eliminating the cumbersome structure of traditional rotary servo joints with conversion mechanisms. They offer significant advantages such as compact structure, fast response speed, high motion accuracy, and excellent dynamic performance. Currently, these joints are widely used in high-end equipment fields such as industrial collaborative robots, high-speed sorting robots, humanoid bionic robots, and special-purpose robots for extreme environments. They are the core foundation for ensuring the overall motion accuracy, response speed, operational stability, and load adaptability of robots, and their dynamic characteristics directly determine the overall operational performance and service life of the robot.

[0003] Currently, the technical means used in the industry to obtain the dynamic characteristics of linear servo joints and verify their motion performance are mainly divided into three categories: physical testing, single software simulation, and simplified model simulation. However, all three methods have obvious technical shortcomings and are difficult to accurately reproduce the actual working state of the joint. Among them, physical testing requires the fabrication of physical prototypes and the construction of dedicated test platforms. Not only are the costs of prototype development, equipment procurement, and test maintenance high, but the testing process is also cumbersome and the testing cycle is long. Furthermore, it cannot be adapted to early-stage product iterations and structural optimizations, making it difficult to quickly verify the dynamic performance of joints under different structures and parameters, which seriously restricts the efficiency of new product development.

[0004] Compared to physical experiments, software simulation offers advantages such as low cost, high efficiency, and iterative capabilities. However, single simulation software has functional limitations and cannot complete full-dimensional electromechanical coupling simulation. The dynamics simulation software ADAMS focuses on multibody dynamics simulation, but its servo control algorithm development and refined transmission system modeling capabilities are insufficient, making it difficult to accurately simulate the dynamic process of motor drive and transmission coordination. While the multi-domain system modeling and simulation software AMESim excels at modeling electromechanical and hydraulic transmission systems, it suffers from low accuracy in its multibody dynamics simulation module and poor simulation effects for rigid and flexible body motion. Therefore, no single software can completely and accurately depict the integrated electromechanical coupling dynamic process of "servo motor-transmission mechanism-load," resulting in significant deviations between simulation results and actual operating conditions.

[0005] While current mainstream co-simulation methods integrate the advantages of multiple software programs, they generally suffer from simplification issues during modeling. Most employ linear or rigid body models for simulation calculations, idealizing the joint transmission chain and assuming the transmission system has no backlash, no friction, and infinite stiffness, completely ignoring the nonlinear factors in actual working conditions. However, in real-world scenarios, the transmission backlash of linear servo joints can cause motion return errors, resulting in collisions and impacts during high-speed reversals; contact surface friction can lead to crawling at low speeds and abrupt changes in trajectory tracking errors; and insufficient structural elastic stiffness can cause elastic deformation and continuous vibration. These nonlinear factors are coupled and work together, which are the key factors affecting the dynamic response accuracy of joints, reducing motion stability, and causing overall machine malfunctions. This is also the main reason for the current disconnect between simulation technology and practical applications.

[0006] Therefore, this application anticipates a co-simulation method that can realistically reflect the dynamic characteristics of linear servo joints under the influence of clearance, friction, and stiffness coupling. Summary of the Invention

[0007] To address the problems existing in the prior art, this invention provides a simulation method, system, device, and medium for the dynamic characteristics of linear servo joints. The aim is to systematically embed three nonlinear factors—transmission clearance, friction, and stiffness—into a co-simulation model, thereby achieving accurate acquisition of the dynamic characteristics of linear servo joints under the influence of nonlinear factors.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] In a first aspect, embodiments of this disclosure provide a simulation method for the dynamic characteristics of a linear servo joint, comprising the following steps:

[0010] Step S1: Establish a multibody dynamics model of the linear servo joint in the dynamics simulation software ADAMS, and establish an initial electromechanical coupling system-level model including the servo motor and control model in the multi-domain system modeling and simulation software AMESim based on the actual working principle of the linear servo joint.

[0011] Step S2: Embed a transmission chain considering nonlinear factors into the initial electromechanical coupling system-level model to obtain an optimized electromechanical coupling system-level model. The transmission chain considering nonlinear factors includes a transmission clearance model, a friction model, and / or a stiffness model.

[0012] Step S3: Using the associated parameters of the multibody dynamics model and the optimized electromechanical coupling system-level model as transfer parameters, a software interface is constructed based on the GSE state equation module of the dynamics simulation software ADAMS and the interface module of the multi-domain system modeling and simulation software AMESim. Based on the software interface, the transfer parameters are transferred in real time, and the linear servo joint is jointly simulated.

[0013] Furthermore, establishing the multibody dynamics model includes the following steps:

[0014] In the 3D software SolidWorks, a 3D model is created based on the dimensions of the linear servo joints and the hinge relationship between the robot's thigh and lower leg, and then the 3D model is imported into the dynamic simulation software ADAMS.

[0015] In the dynamic simulation software ADAMS, a driving mode is added to the prismatic joint of the linear servo joint, and a force is added to the end of the robot's lower leg to generate an initial multibody dynamic model.

[0016] Furthermore, the transmission clearance model is configured in the multi-domain system modeling and simulation software AMESim to connect two spring damping elements with clearance in series. One is used to set the clearance of the reverse planetary roller screw, and the other is used to set the bearing clearance. The bearing clearance is the sum of the clearances of the four-point contact ball bearing and the spherical plain bearing. The sum of the clearance of the reverse planetary roller screw and the bearing clearance is used as the total clearance of the transmission clearance model.

[0017] The friction model is configured to set the friction torque of the bearing in the bearing friction loss element, and the friction torque of the bearing is the sum of the friction torques of the four-point contact ball bearing, the spherical plain bearing and the deep groove ball bearing.

[0018] The friction model is also configured to obtain the friction torque of the reverse planetary roller screw by constructing the Stribeck friction function and introducing the Stribeck friction function into the rotating friction disk element;

[0019] The friction model is also configured to provide frictional resistance to the supporting sealing end in a two-port mass block element with friction.

[0020] The stiffness model is configured to set the transmission stiffness of the reverse planetary roller screw in the screw nut element, set the bearing stiffness in the spring damping element with clearance, and obtain the total equivalent stiffness of the transmission chain.

[0021] Furthermore, the Stribeck friction function include:

[0022] ;

[0023] In the formula, This represents the Coulomb friction torque; This represents the Stribeck friction torque; The torque representing the load on the joint; Indicates Stribeck's speed; Indicates the angular velocity of the mechanism; Indicates the average coefficient of the influence of external forces; Indicates the quadrant determination coefficient.

[0024] Furthermore, the total equivalent stiffness of the transmission chain includes:

[0025] ;

[0026] In the formula, For the overall equivalent stiffness; The axial stiffness of the reverse planetary roller screw; This refers to the axial stiffness of a four-point contact ball bearing. This refers to the radial stiffness of the spherical bearing.

[0027] Furthermore, the associated parameters include:

[0028] Joint load, which is a parameter passed from the dynamic simulation software ADAMS model to the multi-domain system modeling and simulation software AMESim, includes force components in the X, Y and Z directions;

[0029] The joint displacement is a parameter transmitted from the AMESim model (a multi-domain system modeling and simulation software) to the ADAMS dynamics simulation software.

[0030] Furthermore, when transmitting parameters in real time via a software interface, the following steps are included:

[0031] Step A1: The multi-domain system modeling and simulation software AMESim is compiled to generate a dynamic link library;

[0032] Step A2: The dynamic simulation software ADAMS calls the dynamic link library through the GSE state equation module. At each communication moment, the dynamic simulation software ADAMS solves the current joint load by calling the dynamic link library and passes the current joint load as input to the multi-domain system modeling and simulation software AMESim.

[0033] Step A3: The multi-domain system modeling and simulation software AMESim calculates the current joint displacement based on the current joint load and in combination with the optimized electromechanical coupling system-level model.

[0034] Step A4: Return the current joint displacement as output to the dynamic simulation software ADAMS. The dynamic simulation software ADAMS uses the current joint displacement to drive the multibody dynamics model to solve for the joint load at the next moment.

[0035] Step A5: Input the joint load at the next moment into the dynamic link library, and repeat steps A2 to A4 until the co-simulation ends, to obtain a joint response simulation diagram with time as the horizontal axis and joint displacement, joint velocity, and joint load as the vertical axis.

[0036] In a second aspect, embodiments of this disclosure provide a simulation system for the dynamic characteristics of a linear servo joint, comprising:

[0037] The initialization unit is configured to establish a multibody dynamics model of the linear servo joint in the dynamics simulation software ADAMS, and to establish an initial electromechanical coupling system-level model containing the servo motor and control model in the multi-domain system modeling and simulation software AMESim based on the actual working principle of the linear servo joint.

[0038] The optimization unit is configured to embed a transmission chain considering nonlinear factors into the initial electromechanical coupling system-level model to obtain an optimized electromechanical coupling system-level model. The transmission chain considering nonlinear factors includes a transmission clearance model, a friction model, and a stiffness model.

[0039] The simulation unit is configured to use the associated parameters of the multibody dynamics model and the optimized electromechanical coupling system-level model as transmission parameters, construct a software interface based on the GSE state equation module of the dynamics simulation software ADAMS and the interface module of the multi-domain system modeling and simulation software AMESim, and perform real-time data transmission of the transmission parameters based on the software interface to perform joint simulation of the linear servo joint.

[0040] In a third aspect, embodiments of this disclosure provide an electronic device, characterized in that the electronic device comprises:

[0041] At least one processor; and,

[0042] The memory is communicatively connected to the at least one processor; wherein,

[0043] The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the simulation method for the dynamic characteristics of the linear servo joint.

[0044] In a fourth aspect, embodiments of this disclosure provide a non-transitory computer-readable storage medium, characterized in that the non-transitory computer-readable storage medium stores computer instructions for causing the computer to execute the simulation method for the dynamic characteristics of the linear servo joint.

[0045] Compared with the prior art, the present invention has the following beneficial technical effects:

[0046] This invention provides a simulation method, system, device, and medium for the dynamic characteristics of linear servo joints. The method embeds a transmission chain considering nonlinear factors into the initial electromechanical coupling system-level model, resulting in an optimized electromechanical coupling system-level model. The transmission chain considering nonlinear factors includes a transmission clearance model, a friction model, and / or a stiffness model. This solves the problem of treating the transmission chain as an ideal system in existing co-simulation methods, and can realistically reflect the actual dynamic behavior of the joint under the influence of nonlinear factors, providing a reliable basis for performance evaluation in the design phase. The method is based on the GSE state equation module of the dynamic simulation software ADAMS and the interface module of the multi-domain system modeling and simulation software AMESim. The software interface is constructed and real-time data transmission of parameters is performed based on the software interface. This enables the collaborative solution of the multibody dynamics model and the optimized electromechanical coupling system-level model. The complementary advantages of the two can accurately describe the mechanical dynamic characteristics of the joint and finely characterize the electromechanical coupling process of the servo motor-control-transmission chain, overcoming the technical defects of "giving one thing and losing another" in single software simulation. At the same time, when performing co-simulation of linear servo joints, the clearance model, friction model or stiffness model can be selectively activated or shielded. It is possible to obtain the joint dynamic response data under the individual action and arbitrary combination of nonlinear factors under the same co-simulation framework, providing data support for the accurate optimization of the transmission system. Attached Figure Description

[0047] Figure 1 A flowchart of a simulation method for the dynamic characteristics of a linear servo joint in an embodiment of this disclosure is shown;

[0048] Figure 2 A schematic diagram of the nonlinear factors of a linear servo joint according to an embodiment of the present disclosure is shown;

[0049] Figure 3 The diagram illustrates the influence of the transmission clearance model on the displacement response in the nonlinear factors of this disclosure embodiment.

[0050] Figure 4 The diagram illustrates the influence of the transmission clearance model on the joint load response in the nonlinear factors of this disclosure embodiment.

[0051] Figure 5 The diagram illustrates the influence of the friction model on the displacement response in the nonlinear factors of this disclosure embodiment.

[0052] Figure 6 The diagram illustrates the influence of the friction model on the joint load response in the nonlinear factors of this disclosure embodiment.

[0053] Figure 7 The diagram illustrates the influence of the friction model on the velocity response in the nonlinear factors of this disclosure embodiment.

[0054] Figure 8 The diagram illustrates the influence of the stiffness model on the velocity response in the nonlinear factors of this disclosure embodiment.

[0055] Figure 9 The diagram illustrates the influence of the stiffness model on the joint load response in the nonlinear factors of this disclosure embodiment.

[0056] Figure 10 The diagram illustrates the influence of nonlinear factor coupling on displacement response according to an embodiment of this disclosure.

[0057] Figure 11 A diagram illustrating the influence of nonlinear factor coupling on joint load response according to an embodiment of this disclosure is shown.

[0058] Figure 12 The diagram illustrates the influence of coupling on velocity response in the nonlinear factors of this disclosure.

[0059] Figure 13 A diagram of a simulation method apparatus for the dynamic characteristics of a linear servo joint according to an embodiment of this disclosure is shown. Detailed Implementation

[0060] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0061] Figure 1 A flowchart 90 shows a simulation method for the dynamic characteristics of a linear servo joint according to the first embodiment of this disclosure, as shown below. Figure 1 As shown, it includes the following steps:

[0062] In step S101, a multibody dynamics model of the linear servo joint is established in the dynamics simulation software ADAMS, and an initial electromechanical coupling system-level model including the servo motor and control model is established in the multi-domain system modeling and simulation software AMESim based on the actual working principle of the linear servo joint.

[0063] Furthermore, establishing the multibody dynamics model includes the following steps:

[0064] In the 3D software SolidWorks, a 3D model is created based on the dimensions of the linear servo joints and the hinge relationship between the robot's thigh and lower leg, and then the 3D model is imported into the dynamic simulation software ADAMS.

[0065] In the dynamics simulation software ADAMS, a driving mode is added to the prismatic joint of the linear servo joint, and a force is applied to the end of the robot's lower leg to generate an initial multibody dynamics model. Specifically, the driving mode applied to the prismatic joint enables the lower leg to rotate around the thigh, and the force is applied only to the end of the robot's lower leg to simulate the load on the lower leg end.

[0066] In this embodiment, a three-dimensional model is established in the 3D software SolidWorks by combining the joint dimensions and the hinge relationship with the robot's thigh and calf. Non-stress features such as fillets, chamfers, and threads are simplified to improve simulation efficiency. The 3D model is then saved in *.x_t format, which can be recognized by the dynamic simulation software ADAMS, and imported into the dynamic simulation software ADAMS. The units are set to MMKS—distance in millimeters (mm), mass in kilograms (kg), joint load in Newtons (N), and time in seconds (s).

[0067] Table 1 lists the main constraints used in the linear servo joint in this embodiment. It should be noted that some components have their mutual constraints defined as fixed constraints due to synchronous movement. For example, the joint bearing housing and the joint housing are relatively fixed, but this is not shown in the table.

[0068] Table 1. Main constraints of the linear servo joint dynamics model

[0069]

[0070] The rotating joint between the thigh and the calf is located at the hinge point between the lower end of the thigh and the upper end of the calf; the rotating joint between the thigh and the upper joint bearing is located at the hinge point between the thigh and the upper end of the joint; the rotating joint between the calf and the lower joint bearing is located at the hinge point between the calf and the lower end of the joint; and the sliding joint between the nut and the push rod is oriented along the axis of the nut and the push rod.

[0071] At the same time, necessary driving methods are added according to the actual situation. For example, in the dynamic simulation software ADAMS, displacement drive is created on the sliding joint of the push rod and nut, and the driving function is set to read the output value of the GSE state equation module.

[0072] Then, the directions of the relevant forces are defined in the dynamic simulation software ADAMS. For example, they can be defined along the coordinate axes or along the direction of the line connecting two points. To simulate the force on the joint when the robot's lower leg bends, a vertically upward force of 500N is applied to the robot's lower leg.

[0073] Next, proceed to step S102.

[0074] In step S102, a transmission chain considering nonlinear factors is embedded in the initial electromechanical coupling system-level model to obtain an optimized electromechanical coupling system-level model. The transmission chain considering nonlinear factors includes a transmission clearance model, a friction model, and / or a stiffness model.

[0075] It should be noted that, in this embodiment, the multi-domain system modeling and simulation software AMESim is a graphical programming language with an intuitive presentation that directly reflects the working principle of the system. The graphical program of the linear servo joint is established in AMESim according to its actual working principle, mainly including a control module, a motor module, and a mechanical module. The control strategy of the control module adopts a three-loop PID control with position, speed, and current loops. The motor is a permanent magnet synchronous motor, and its parameters are shown in Table 2. The lead screw and nut element is used to simulate a reverse planetary roller screw, converting the rotational motion of the permanent magnet synchronous motor into linear motion. In AMESim, the lead screw diameter is set to 7.2mm and the lead is set to 1.5mm to calculate the linear displacement when the rotational motion is converted into linear motion. At this time, since the rotational motion reaches the lead screw and nut element, only the nonlinear factors corresponding to the bearing friction loss element and the rotating friction disk element exist in the joint displacement.

[0076] Table 2 Parameter Table of Permanent Magnet Synchronous Motor

[0077]

[0078] Furthermore, such as Figure 2 As shown, the transmission clearance model is configured in the multi-domain system modeling and simulation software AMESim by connecting two spring damping elements MCLC0AA with clearance in series. One is used to set the clearance of the reverse planetary roller screw, and the other is used to set the bearing clearance. The bearing clearance is the sum of the clearances of the four-point contact ball bearing and the spherical plain bearing. The sum of the clearance of the reverse planetary roller screw and the bearing clearance is used as the total clearance of the transmission clearance model.

[0079] The friction model is configured to set the friction torque of the bearing in the bearing friction loss element TRBE000B, and the friction torque of the bearing is the sum of the friction torques of the four-point contact ball bearing, the spherical plain bearing and the deep groove ball bearing.

[0080] The friction model is also configured to obtain the friction torque of the reverse planetary roller screw by constructing the Stribeck friction function and introducing the Stribeck friction function into the rotating friction disk element MECFRIR0A.

[0081] The friction model is also configured to provide frictional resistance to the supporting sealing end in the frictional dual-port mass block element MAS11.

[0082] The stiffness model is configured to set the transmission stiffness of the reverse planetary roller screw in the screw nut element SRWNT1, set the bearing stiffness in the spring damping element MCLC0AA with clearance, and obtain the total equivalent stiffness of the transmission chain.

[0083] Specifically, the Stribeck friction function include:

[0084] ;

[0085] In the formula, This represents the Coulomb friction torque; This represents the Stribeck friction torque; The torque representing the load on the joint; Indicates Stribeck's speed; Indicates the angular velocity of the mechanism; Indicates the average coefficient of the influence of external forces; Indicates the quadrant determination coefficient.

[0086] It should be noted that the rotational angular velocity of the mechanism The torque loaded on the joint is acquired in real time via a speed sensor. The force is acquired in real time through a force sensor at the load end.

[0087] Specifically, the total equivalent stiffness of the transmission chain includes:

[0088] ;

[0089] In the formula, For the overall equivalent stiffness; The axial stiffness of the reverse planetary roller screw; This refers to the axial stiffness of a four-point contact ball bearing. This refers to the radial stiffness of the spherical bearing.

[0090] The nonlinear transmission chain operates as follows: After simulation, the control unit drives the motor to rotate according to the joint displacement command. This rotational motion passes sequentially through the bearing friction loss element TRBE000B and the rotating friction disk element MECFRIR0A to the lead screw nut element SRWNT1. In SRWNT1, it is converted into linear motion, which then passes through a spring-damped element MCLC0AA with clearance, a friction-bearing dual-port mass element MAS11, and another spring-damped element MCLC0AA with clearance before outputting the joint displacement considering nonlinear factors. This motion transmission process comprehensively considers various nonlinear factors such as clearance, friction, and stiffness within the joint. The final output of the joint displacement, considering nonlinear factors, reflects the losses and vibration characteristics during the actual joint motion transmission process. Similarly, the load transmission path of the joint also includes various nonlinear factors, thus reflecting the impact vibration characteristics during the load transmission process within the joint.

[0091] Next, proceed to step S103.

[0092] In step S103, the associated parameters of the multibody dynamics model and the optimized electromechanical coupling system-level model are used as transmission parameters. A software interface is constructed based on the GSE state equation module of the dynamics simulation software ADAMS and the interface module of the multi-domain system modeling and simulation software AMESim. Real-time data transmission of the transmission parameters is performed based on the software interface to perform joint simulation of the linear servo joint.

[0093] Specifically, the associated parameters include:

[0094] Joint load, which is a parameter passed from the dynamic simulation software ADAMS model to the multi-domain system modeling and simulation software AMESim, includes force components in the X, Y and Z directions;

[0095] The joint displacement is a parameter transmitted from the AMESim model (a multi-domain system modeling and simulation software) to the ADAMS dynamics simulation software.

[0096] Furthermore, when transmitting parameters in real time via a software interface, the following steps are included:

[0097] Step A1: The multi-domain system modeling and simulation software AMESim is compiled to generate a dynamic link library;

[0098] Step A2: The dynamic simulation software ADAMS calls the dynamic link library through the GSE state equation module. At each communication moment, the dynamic simulation software ADAMS solves the current joint load by calling the dynamic link library and passes the current joint load as input to the multi-domain system modeling and simulation software AMESim.

[0099] Step A3: The multi-domain system modeling and simulation software AMESim calculates the current joint displacement based on the current joint load and in combination with the optimized electromechanical coupling system-level model.

[0100] Step A4: Return the current joint displacement as output to the dynamic simulation software ADAMS. The dynamic simulation software ADAMS uses the current joint displacement to drive the multibody dynamics model to solve for the joint load at the next moment.

[0101] Step A5: Input the joint load at the next moment into the dynamic link library, and repeat steps A2 to A4 until the co-simulation ends, to obtain a joint response simulation diagram with time as the horizontal axis and joint displacement, joint velocity, and joint load as the vertical axis.

[0102] Specifically, in co-simulation, the dynamic simulation software ADAMS obtains the current joint load by calling the dynamic link library generated by the multi-domain system modeling and simulation software AMESim. Essentially, this process encapsulates the optimized electromechanical coupling system-level model, which includes nonlinear factors, constructed by AMESim into a standardized function interface. This allows the solver in ADAMS to immediately obtain the corresponding joint motion response by passing in the current joint load at each integration step, much like calling a subroutine. The specific implementation process is as follows:

[0103] First, using the code export function of the multi-domain system modeling and simulation software AMESim, the optimized electromechanical coupling system-level model of the integrated linear servo joint, along with its internal solution algorithm, is compiled to generate a dynamic link library file suitable for the dynamic simulation software ADAMS environment. The dynamic link library file essentially encapsulates all the mathematical relationships and nonlinear characteristics of the model, and the external interface of the dynamic link library file conforms to the general state equation specification defined by the dynamic simulation software ADAMS.

[0104] At the start of the co-simulation, the dynamic simulation software ADAMS loads the dynamic link library file. Upon entering each simulation time step, the ADAMS solver calls the existing calculation functions in the dynamic link library file, passing the current joint load value calculated in the current step as input parameters to the calculation function. At this time, the AMESim solver, a multi-domain system modeling and simulation software within the dynamic link library file, is driven. Based on the received current joint load, the current internal state of the initial electromechanical coupling system-level model, and the transmission chain of embedded nonlinear factors, it advances one solution step to calculate the current joint displacement. This current joint displacement is then returned to the ADAMS dynamic simulation software as the function's output parameter.

[0105] Thus, the dynamic simulation software ADAMS, through a single function call, synchronously retrieves joint displacements, including nonlinear factors such as clearance, friction, and stiffness, from the dynamic link library file. This data is then used to update the motion state of the joints in the multibody dynamics model, thereby completing the co-simulation for that time step. This process is repeated cyclically, achieving real-time conversion and transmission of "joint load input → nonlinear dynamics calculation within the dynamic link library file → joint displacement output."

[0106] In this embodiment, Table 3 shows the relationship between the input and output variables between the dynamic simulation software ADAMS and the multi-domain system modeling and simulation software AMESim.

[0107] Table 3 Variables of the ADAMS and AMESim Model Interfaces

[0108]

[0109] In the multi-domain system modeling and simulation software AMESim, create an interface module of type "Adams(co-simulation)". In the pop-up parameter setting dialog box, set the number of input variables to 1 and define the name as "var_displacement" to correspond to joint displacement; set the number of output variables to 3 and name them "var_forceX", "var_forceY", and "var_forceZ" respectively, corresponding to the load forces in the X, Y, and Z directions of the joint transmitted from the dynamic simulation software ADAMS. At the same time, insert the signal processing element "FXYZ" to synthesize the load forces in the three directions of the joint to form the joint load, and apply the joint load to the load end of the joint in the multi-domain system modeling and simulation software AMESim. After setting, set the simulation step size to 0.001s and the simulation time to 2s in the multi-domain system modeling and simulation software AMESim, run the co-simulation, and automatically generate the dynamic link library file "sum_guanjie_320_.dll".

[0110] In the dynamic simulation software ADAMS, create data cells “ARRAY_U”, “ARRAY_X”, and “ARRAY_Y”. Define the load forces in the X, Y, and Z directions of the joint as the U array, the joint displacements as the Y array, and the X array as the state variables required for the equations to run. Set the input array of the GSE state equations in the GSE state equations module to “ARRAY_U” and the output array to “ARRAY_Y”. Set the function driving the moving joint on the nut and push rod to read the output value Y of the GSE state equations. In the solver dialog box for dynamic analysis, select “Execute” and specify the path to the dynamic link library file generated by the multi-domain system modeling and simulation software AMESim in the solver library, such as “D: / Lian_He_Fang_Zhen / sum_guanjie_320_.dll”. After setting up, create a simulation script, set the step size to 0.001s, the termination time to 2s, and run the simulation. The dynamic simulation software ADAMS solver calls the dynamic link library of the multi-domain system modeling and simulation software AMESim at each communication moment to pass the current joint load to AMESim. After receiving the joint load, AMESim solves the joint displacement and passes it to the dynamic simulation software ADAMS. The two solve alternately until the simulation ends.

[0111] After the simulation, the joint displacement, joint velocity, and joint load response were exported as ".data" format files that Origin can recognize in the multi-domain system modeling and simulation software AMESim. The data was imported into Origin, and a graph of the joint response was plotted with time on the x-axis and joint displacement, joint velocity, and joint load on the y-axis for comparative analysis. It should be noted that AMESim solves for the joint's motion parameters, including joint displacement, joint velocity, and joint acceleration, and the data transmitted to the dynamic simulation software ADAMS also consists of these motion parameters. In this embodiment, joint displacement necessarily includes joint velocity and joint acceleration; that is, joint velocity and joint acceleration can be obtained simultaneously through joint displacement alone.

[0112] Only the nonlinearity of the clearance was retained in the simulation model. The total clearance of the transmission chain was set to 0.05 mm, 0.1 mm, and 0.2 mm, respectively. The influence of the clearance on the dynamic characteristics of the joint was analyzed, and the results are as follows: Figure 3 and Figure 4 As shown, by Figure 3 and Figure 4It is known that the presence of the gap causes the system displacement to lag, and the lag time is extended as the gap increases; at the same time, the gap will cause an impact at the initial moment of the load response, and the larger the gap, the higher the amplitude of the impact force.

[0113] By removing all nonlinear factors from the simulation model and retaining only the frictional nonlinear factor, the dynamic responses of the joint with and without friction were obtained through simulation. The results are as follows. Figure 5 , Figure 6 and Figure 7 As shown. By Figure 5 , Figure 6 and Figure 7 It can be seen that after introducing frictional resistance, the system displacement response speed slows down and the time required to reach steady state is longer; the error increases in steady state, reducing the positioning accuracy of the system; and in the low-speed region, the system frequently switches between dynamic and static frictional forces, and the Stribeck effect exacerbates the system speed fluctuation.

[0114] Only the stiffness nonlinearity factor is retained in the simulation model, and the overall equivalent stiffness of the transmission chain is set to 1.11 × 10⁻⁶. 8 N / m, 1.11×10 7 N / m, 1.11×10 6 N / m, the effect of stiffness on the dynamic characteristics of the joint was analyzed, and the results are as follows: Figure 8 and Figure 9 As shown, by Figure 8 and Figure 9 It can be seen that as the stiffness decreases, the oscillation amplitude of the load force increases; at a stiffness of 1.11 × 10⁻⁶, the oscillation amplitude of the load force increases. 6 At N / m, the system load force response lags significantly; as the system stiffness decreases, the amplitude of velocity oscillations increases; at a stiffness of 1.11 × 10⁻⁶ N / m, the system load force response lags significantly. 6 When the speed is N / m, the system speed response lags, and the maximum speed decreases.

[0115] Figure 10 , Figure 11 and Figure 12 Table 4 shows the dynamic response of a joint under the coupled effects of three nonlinear factors: clearance, friction, and stiffness. The values ​​of each nonlinear factor are shown in Table 4.

[0116] Table 4. Values ​​of each nonlinear factor

[0117]

[0118] Depend on Figure 6 As shown in Table 4, after considering nonlinear factors, the displacement response, load force response, and speed response of the linear servo joint all exhibit lag, and with the increase of amplitude, the displacement steady-state error increases, and the system's speed, stability, and accuracy decrease.

[0119] The second embodiment of the present invention also provides a simulation system for the dynamic characteristics of a linear servo joint, comprising:

[0120] The initialization unit is configured to establish a multibody dynamics model of the linear servo joint in the dynamics simulation software ADAMS, and to establish an initial electromechanical coupling system-level model containing the servo motor and control model in the multi-domain system modeling and simulation software AMESim based on the actual working principle of the linear servo joint.

[0121] The optimization unit is configured to embed a transmission chain considering nonlinear factors into the initial electromechanical coupling system-level model to obtain an optimized electromechanical coupling system-level model. The transmission chain considering nonlinear factors includes a transmission clearance model, a friction model, and a stiffness model.

[0122] The simulation unit is configured to use the associated parameters of the multibody dynamics model and the optimized electromechanical coupling system-level model as transfer parameters, construct a software interface based on the GSE state equation module of the dynamics simulation software ADAMS and the interface module of the multi-domain system modeling and simulation software AMESim, and perform real-time data transfer of the transfer parameters based on the software interface to perform joint simulation of the linear servo joint. The third embodiment of the present invention also provides an electronic device, which includes:

[0123] At least one processor; and,

[0124] The memory is communicatively connected to the at least one processor; wherein,

[0125] The memory stores instructions that can be executed by the at least one processor, which enables the at least one processor to perform a simulation method for the dynamic characteristics of a linear servo joint in any of the foregoing embodiments.

[0126] The fourth embodiment of the present invention also provides a non-transitory computer-readable storage medium storing computer instructions for causing the computer to execute the simulation method for the dynamic characteristics of a linear servo joint as described in any of the foregoing embodiments.

[0127] The fifth embodiment of the present invention also provides a computer program product, which includes a computing program stored on a non-transitory computer-readable storage medium. The computer program includes program instructions that, when executed by a computer, cause the computer to perform a simulation method for the dynamic characteristics of a linear servo joint according to any of the foregoing embodiments.

[0128] Figure 13The illustration shows a method or device 1000 implementing an embodiment of the present invention. In some embodiments, more or fewer devices may be included than illustrated. In some embodiments, it may be implemented using a single or multiple devices. In some embodiments, it may be implemented using cloud-based or distributed devices.

[0129] like Figure 13 As shown, device 1000 includes a processor 1001 for performing various appropriate operations and processes based on programs and / or data stored in read-only memory (ROM) 1002 or programs and / or data loaded from storage portion 1008 into random access memory (RAM) 1003. Processor 1001 may be a multi-core processor or may contain multiple processors. In some embodiments, processor 1001 may include a general-purpose main processor and one or more special coprocessors, such as a central processing unit (CPU), graphics processing unit (GPU), neural network processor (NPU), digital signal processor (DSP), etc. Various programs and data required for the operation of device 1000 are also stored in RAM 1003. Processor 1001, ROM 1002, and RAM 1003 are interconnected via bus 1004. Input / output (I / O) interface 1005 is also connected to bus 1004.

[0130] The processor and memory described above are used together to execute programs stored in the memory. When the program is executed by a computer, it can implement the methods, steps, or functions described in the above embodiments.

[0131] The following components are connected to I / O interface 1005: an input section 1006 including a keyboard, mouse, touchscreen, etc.; an output section 1007 including a cathode ray tube (CRT), liquid crystal display (LCD), etc., and speakers, etc.; a storage section 1008 including a hard disk, etc.; and a communication section 1009 including a network interface card such as a LAN card, modem, etc. The communication section 1009 performs communication processing via a network such as the Internet. A drive 1010 is also connected to I / O interface 1005 as needed. A removable medium 1011, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., is installed on drive 1010 as needed so that computer programs read from it can be installed into storage section 1008 as needed. Figure 13 The diagram only shows a portion of the components and does not imply that the device 1000 only includes... Figure 13 The components shown.

[0132] The systems, devices, modules, or units described in the above embodiments can be implemented by a computer or its associated components. The computer may be, for example, a mobile terminal, smartphone, personal computer, laptop computer, in-vehicle human-machine interface device, personal digital assistant, media player, navigation device, game console, tablet computer, wearable device, smart TV, Internet of Things system, smart home, industrial computer, server, or a combination thereof.

[0133] Although not shown, in this embodiment of the invention, a computer-readable storage medium is provided, on which a computer program / instruction is stored, which, when executed by a processor, implements the simulation method for the dynamic characteristics of a linear servo joint as described in the embodiment.

[0134] Storage media in embodiments of the present invention include articles that are permanent and non-permanent, removable and non-removable, capable of storing information by any method or technology. Examples of storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transfer medium that can be used to store information accessible by a computing device.

[0135] Although not shown, embodiments of the present invention also provide a computer program product, including: a computer program / instructions that, when executed by a processor, implement the simulation method for the dynamic characteristics of a linear servo joint as described in the embodiments.

[0136] The methods, programs, systems, apparatuses, etc., in embodiments of the present invention can be executed or implemented in one or more networked computers, or practiced in a distributed computing environment. In the embodiments of this specification, in these distributed computing environments, tasks can be performed by remote processing devices connected via a communication network.

Claims

1. A simulation method for the dynamic characteristics of a linear servo joint, characterized in that, Includes the following steps: Step S1: Establish a multibody dynamics model of the linear servo joint in the dynamics simulation software ADAMS, and establish an initial electromechanical coupling system-level model including the servo motor and control model in the multi-domain system modeling and simulation software AMESim based on the actual working principle of the linear servo joint. Step S2: Embed a transmission chain considering nonlinear factors into the initial electromechanical coupling system-level model to obtain an optimized electromechanical coupling system-level model. The transmission chain considering nonlinear factors includes a transmission clearance model, a friction model, and / or a stiffness model. Step S3: Using the associated parameters of the multibody dynamics model and the optimized electromechanical coupling system-level model as transfer parameters, a software interface is constructed based on the GSE state equation module of the dynamics simulation software ADAMS and the interface module of the multi-domain system modeling and simulation software AMESim. Based on the software interface, the transfer parameters are transferred in real time, and the linear servo joint is jointly simulated.

2. The simulation method for the dynamic characteristics of a linear servo joint according to claim 1, characterized in that, The steps involved in establishing the multibody dynamics model are as follows: In the 3D software SolidWorks, a 3D model is created based on the dimensions of the linear servo joints and the hinge relationship between the robot's thigh and lower leg, and then the 3D model is imported into the dynamic simulation software ADAMS. In the dynamic simulation software ADAMS, a driving mode is added to the prismatic joint of the linear servo joint, and a force is added to the end of the robot's lower leg to generate an initial multibody dynamic model.

3. The simulation method for the dynamic characteristics of a linear servo joint according to claim 1, characterized in that, The transmission clearance model is configured in the multi-domain system modeling and simulation software AMESim to connect two spring damping elements with clearance in series. One element is used to set the clearance of the reverse planetary roller screw, and the other element is used to set the bearing clearance. The bearing clearance is the sum of the clearances of the four-point contact ball bearing and the spherical plain bearing. The sum of the clearance of the reverse planetary roller screw and the bearing clearance is used as the total clearance of the transmission clearance model. The friction model is configured to set the friction torque of the bearing in the bearing friction loss element, and the friction torque of the bearing is the sum of the friction torques of the four-point contact ball bearing, the spherical plain bearing and the deep groove ball bearing. The friction model is also configured to obtain the friction torque of the reverse planetary roller screw by constructing the Stribeck friction function and introducing the Stribeck friction function into the rotating friction disk element; The friction model is also configured to provide frictional resistance to the supporting sealing end in a two-port mass block element with friction. The stiffness model is configured to set the transmission stiffness of the reverse planetary roller screw in the screw nut element, set the bearing stiffness in the spring damping element with clearance, and obtain the total equivalent stiffness of the transmission chain.

4. The simulation method for the dynamic characteristics of a linear servo joint according to claim 3, characterized in that, The Stribeck friction function include: ； In the formula, This represents the Coulomb friction torque; This represents the Stribeck friction torque; The torque representing the load on the joint; Indicates Stribeck's speed; Indicates the angular velocity of the mechanism; Indicates the average coefficient of the influence of external forces; Indicates the quadrant determination coefficient.

5. The simulation method for the dynamic characteristics of a linear servo joint according to claim 3, characterized in that, The total equivalent stiffness of the transmission chain includes: ； In the formula, For the overall equivalent stiffness; The axial stiffness of the reverse planetary roller screw; This refers to the axial stiffness of a four-point contact ball bearing. This refers to the radial stiffness of the spherical bearing.

6. The simulation method for the dynamic characteristics of a linear servo joint according to claim 1, characterized in that, The associated parameters include: Joint load, which is a parameter passed from the dynamic simulation software ADAMS model to the multi-domain system modeling and simulation software AMESim, includes force components in the X, Y and Z directions; The joint displacement is a parameter transmitted from the AMESim model (a multi-domain system modeling and simulation software) to the ADAMS dynamics simulation software.

7. The simulation method for the dynamic characteristics of a linear servo joint according to claim 6, characterized in that, When transmitting parameters in real time via a software interface, the following steps are included: Step A1: The multi-domain system modeling and simulation software AMESim is compiled to generate a dynamic link library; Step A2: The dynamic simulation software ADAMS calls the dynamic link library through the GSE state equation module. At each communication moment, the dynamic simulation software ADAMS solves the current joint load by calling the dynamic link library and passes the current joint load as input to the multi-domain system modeling and simulation software AMESim. Step A3: The multi-domain system modeling and simulation software AMESim calculates the current joint displacement based on the current joint load and in combination with the optimized electromechanical coupling system-level model. Step A4: Return the current joint displacement as output to the dynamic simulation software ADAMS. The dynamic simulation software ADAMS uses the current joint displacement to drive the multibody dynamics model to solve for the joint load at the next moment. Step A5: Input the joint load at the next moment into the dynamic link library, and repeat steps A2 to A4 until the co-simulation ends, to obtain a joint response simulation diagram with time as the horizontal axis and joint displacement, joint velocity, and joint load as the vertical axis.

8. A simulation system for the dynamic characteristics of a linear servo joint, characterized in that, The simulation method based on the dynamic characteristics of the linear servo joint according to any one of claims 1-7 includes: The initialization unit is configured to establish a multibody dynamics model of the linear servo joint in the dynamics simulation software ADAMS, and to establish an initial electromechanical coupling system-level model containing the servo motor and control model in the multi-domain system modeling and simulation software AMESim based on the actual working principle of the linear servo joint. The optimization unit is configured to embed a transmission chain considering nonlinear factors into the initial electromechanical coupling system-level model to obtain an optimized electromechanical coupling system-level model. The transmission chain considering nonlinear factors includes a transmission clearance model, a friction model, and a stiffness model. The simulation unit is configured to use the associated parameters of the multibody dynamics model and the optimized electromechanical coupling system-level model as transmission parameters, construct a software interface based on the GSE state equation module of the dynamics simulation software ADAMS and the interface module of the multi-domain system modeling and simulation software AMESim, and perform real-time data transmission of the transmission parameters based on the software interface to perform joint simulation of the linear servo joint.

9. An electronic device, characterized in that, The electronic device includes: At least one processor; and, The memory is communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the simulation method for the dynamic characteristics of a linear servo joint as described in any one of claims 1 to 7.

10. A non-transitory computer-readable storage medium, characterized in that, The non-transitory computer-readable storage medium stores computer instructions for causing the computer to execute the simulation method for the dynamic characteristics of a linear servo joint as described in any one of claims 1 to 7.

Images