Specified time control method and device, electronic equipment and storage medium

Abstract

The invention discloses a specified time control method and device, electronic equipment and a storage medium, and the method comprises the steps: setting a displacement vector, a speed vector, target position information and target speed information of a mechanical arm; the displacement vector, the speed vector, the target position information, the target speed information and preset control time are input into a preset time controller, a control signal is output, the preset time controller is established based on a preset projection strategy and a PD controller, and the preset projection strategy is used for establishing connection between an infinite time domain and a finite time domain; and controlling the mechanical arm to perform dynamic trajectory tracking according to the control signal. Thus, real-time target position information and target speed information are introduced through the PD controller, dynamic trajectory tracking can be achieved, asymptotic stability of the mechanical arm is controlled, meanwhile, time in the infinite time domain is mapped to preset control time in the finite time domain through the preset projection strategy, and convergence in the preset control time is achieved.

Description

Technical Field

[0001] The present application relates to the field of automatic control technology, and in particular to a designated time control method, device, electronic device and storage medium. Background Art

[0002] The dynamic trajectory tracking problem is a widespread problem in control systems. It involves enabling a dynamic system (such as a robotic arm) to accurately follow a given and time-varying trajectory. This trajectory is usually defined by a series of parameters such as position, velocity, acceleration, etc. Because the parameters change over time, it is called a dynamic trajectory.

[0003] In order to solve the dynamic trajectory tracking problem, various control methods are usually used, such as adaptive control, robust control, etc. However, in the current technology, most of the research is about discussing trajectory tracking control in the infinite time domain. In the existing controller design that meets the convergence performance requirements, the final convergence time is a conservative approximate estimate, that is, the existing technology does not pay attention to the specific time when the tracking error converges to the steady state. In practical applications, it is often necessary to pre-set a specific convergence time, that is, the existing controller design cannot adapt to the actual application requirements. Although the finite time control method can make the system converge to a steady state within a finite time, it has no constraints on transient states. In addition, for a class of preset performance control of trajectories, this type of control can simultaneously meet the transient and steady state requirements of the trajectory, but it cannot clearly give the time when the control system enters the steady state. Therefore, there is an urgent need for a control method that can pre-set a specific convergence time. Summary of the invention

[0004] The present application provides a specified time control method, device, electronic device and storage medium, which can preset a specific convergence time and realize dynamic trajectory tracking within the preset control time.

[0005] In a first aspect, the present application provides a specified time control method, which is applied to a robotic arm, and the method comprises:

[0006] Setting the displacement vector, velocity vector, target position information and target velocity information of the robotic arm;

[0007] Input the displacement vector, the velocity vector, the target position information, the target velocity information and the preset control time into a preset time controller, and output a control signal, wherein the preset time controller is established based on a preset projection strategy and a PD controller, and the preset projection strategy is used to establish a connection between an infinite time domain and a finite time domain;

[0008] The robot arm is controlled to perform dynamic trajectory tracking according to the control signal.

[0009] Optionally, the process of obtaining the preset time controller includes:

[0010] Establishing the Lagrangian dynamic equation corresponding to the robotic arm; the Lagrangian dynamic equation is used to describe the motion law of the robotic arm;

[0011] According to the control target requirements, the target position information and target speed information of the robot arm are set;

[0012] Constructing a PD controller; the PD controller is constructed according to the weighted sum of a proportional term and a differential term; the proportional term is the product of a proportional gain and the position error; the differential term is the product of a differential gain and the speed error; the position error is defined according to an actual displacement vector and the target position information; the speed error is defined according to an actual speed vector and the target speed information; the actual displacement vector and the actual speed vector are obtained according to the Lagrangian dynamic equation;

[0013] Establishing a preset projection strategy according to a time transformation function; the time transformation function is used to map an infinite time domain to a finite time domain; the preset projection strategy is used to project the actual displacement vector, the actual velocity vector and the actual acceleration vector to obtain a projected position vector, a projected velocity vector and a projected acceleration vector;

[0014] According to the preset projection strategy and the PD controller, a preset time controller is constructed, and the preset time controller is used to output a control signal, and the control signal is used to control the robotic arm to reach the projection position vector and the projection velocity vector within a preset time.

[0015] Optionally, constructing a preset time controller according to the preset projection strategy and the PD controller includes:

[0016] Establishing a projection function based on the time transformation function and the preset projection strategy;

[0017] The preset time controller is constructed according to the projection function and the PD controller.

[0018] Optionally, the control function expression corresponding to the PD controller is:

[0019] Among them, K p is the proportional gain, K d is the differential gain, q is the actual displacement vector, q d is the target location information, is the actual speed information, is the target speed information.

[0020] Optionally, establishing the Lagrangian dynamics equation corresponding to the robotic arm includes:

[0021] A Lagrangian energy function corresponding to the robotic arm is established by using a second-class Lagrangian method, wherein the Lagrangian energy function is defined as the difference between the total kinetic energy and the total potential energy in the control system where the robotic arm is located;

[0022] The Lagrangian energy function is differentiated to obtain the Lagrangian dynamic equation; the Lagrangian energy function is used to describe the dynamic state of the control system where the robotic arm is located.

[0023] Optionally, the Lagrangian energy function is:

[0024]

[0025] Where q is the displacement vector; is the velocity vector.

[0026] Optionally, the Lagrangian dynamic equation is:

[0027]

[0028] Where, M(q)=[M ij ]; M(q)∈R n×n is the inertia matrix, q is the displacement vector, is the velocity vector, is the acceleration vector; is the centrifugal force and Coriolis moment; G(q)∈R n is the gravitational moment; is the resistance torque, u∈R n To control the torque.

[0029] In a second aspect, the present application provides a designated time control device, applied to a robotic arm, the device comprising:

[0030] An acquisition unit, used for setting a displacement vector, a velocity vector, target position information and a target velocity information of the robotic arm;

[0031] An input unit, used to input the displacement vector, the velocity vector, the target position information, the target velocity information and the preset control time into a preset time controller, and output a control signal, wherein the preset time controller is established based on a preset projection strategy and a PD controller, and the preset projection strategy is used to establish a connection between an infinite time domain and a finite time domain;

[0032] A control unit is used to control the robotic arm to perform dynamic trajectory tracking according to the control signal.

[0033] Optionally, the acquisition unit includes:

[0034] A dynamic equation establishment subunit is used to establish the Lagrangian dynamic equation corresponding to the robotic arm; the Lagrangian dynamic equation is used to describe the motion law of the robotic arm;

[0035] A setting subunit, used to set the target position information and target speed information of the robot arm according to the control target requirements;

[0036] A construction subunit is used to construct a PD controller; the PD controller is constructed according to the weighted sum of a proportional term and a differential term; the proportional term is the product of a proportional gain and the position error; the differential term is the product of a differential gain and the speed error; the position error is defined according to an actual displacement vector and the target position information; the speed error is defined according to an actual speed vector and the target speed information;

[0037] A projection strategy subunit, used to establish a preset projection strategy according to a time transformation function; the time transformation function is used to map an infinite time domain to a finite time domain; the preset projection strategy is used to project the actual displacement vector, the actual velocity vector and the actual acceleration vector to obtain a projected projection position vector, a projection velocity vector and a projection acceleration vector;

[0038] A construction subunit is used to construct a preset time controller according to the preset projection strategy and the PD controller, and the preset time controller is used to output a control signal, and the control signal is used to control the robotic arm to reach the projection position vector and the projection velocity vector within a preset time.

[0039] Optionally, the construction subunit is specifically used to:

[0040] Establishing a projection function based on the time transformation function and the preset projection strategy;

[0041] The preset time controller is constructed according to the projection function and the PD controller.

[0042] Optionally, the control function expression corresponding to the PD controller is:

[0043] Among them, K p is the proportional gain, K d is the differential gain, q is the actual displacement vector, q d is the target location information, is the actual speed information, is the target speed information.

[0044] Optionally, the kinetic equation establishment subunit is specifically used for:

[0045] A Lagrangian energy function corresponding to the robotic arm is established by using a second-class Lagrangian method, wherein the Lagrangian energy function is defined as the difference between the total kinetic energy and the total potential energy in the control system where the robotic arm is located;

[0046] The Lagrangian energy function is differentiated to obtain the Lagrangian dynamic equation; the Lagrangian energy function is used to describe the dynamic state of the control system where the robotic arm is located.

[0047] Optionally, the Lagrangian energy function is:

[0048]

[0049] Where q is the displacement vector; is the velocity vector.

[0050] Optionally, the Lagrangian dynamic equation is:

[0051]

[0052] Where, M(q)=[M ij ]; M(q)∈R n×n is the inertia matrix, q is the displacement vector, is the velocity vector, is the acceleration vector; is the centrifugal force and Coriolis moment; G(q)∈R n is the gravitational moment; is the resistance torque, u∈R n To control the torque.

[0053] In a third aspect, the present application further provides an electronic device, the electronic device comprising a processor and a memory:

[0054] The memory is used to store computer programs;

[0055] The processor is used to execute the method provided in the first aspect according to the computer program.

[0056] In a fourth aspect, the present application further provides a computer-readable storage medium, wherein the computer-readable storage medium is used to store a computer program, and the computer program is used to execute the method provided in the first aspect above.

[0057] It can be seen that this application has the following beneficial effects:

[0058] The present application provides a specified time control method, device, electronic device and storage medium, in which the displacement vector, velocity vector, target position information and target velocity information of the robot are set; the displacement vector, velocity vector, target position information, target velocity information and preset control time are input into a preset time controller, and a control signal is output, the preset time controller is established based on a preset projection strategy and a PD controller, and the preset projection strategy is used to establish a connection between an infinite time domain and a finite time domain; the robot is controlled to perform dynamic trajectory tracking according to the control signal. In this way, by introducing real-time target position information and target velocity information through the PD controller, dynamic trajectory tracking can be achieved and the progressive stability of the robot can be controlled. At the same time, the time in the infinite time domain is mapped to the preset control time in the finite time domain through the preset projection strategy, so as to achieve convergence within the preset control time. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0060] Figure 1 A schematic diagram of a flow chart of a designated time control method in an embodiment of the present application;

[0061] Figure 2 This is a design idea diagram of a preset time controller in an embodiment of the present application;

[0062] Figure 3 This is a schematic diagram of the tracking effect of different target position information under a preset control time in an embodiment of the present application;

[0063] Figure 4 This is another schematic diagram of tracking effect of different target position information under a preset control time in an embodiment of the present application;

[0064] Figure 5 This is a comparison diagram of tracking effects when parameter a is different and parameters b and c are the same in the preset projection function in the embodiment of the present application;

[0065] Figure 6 This is a comparison diagram of tracking effects when parameters b and c are different and parameter a is the same in the preset projection function in the embodiment of the present application;

[0066] Figure 7 A schematic diagram of the structure of a designated time control device 700 provided in an embodiment of the present application;

[0067] Figure 8 A schematic diagram of the structure of an electronic device 800 provided in an embodiment of the present application. DETAILED DESCRIPTION

[0068] The multiple involved in the embodiments of the present application means greater than or equal to two. It should be noted that in the description of the embodiments of the present application, the words "first", "second", etc. are only used for the purpose of distinguishing the description, and cannot be understood as indicating or implying relative importance, nor can they be understood as indicating or implying an order.

[0069] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the embodiments of the present application are further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It is understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. In addition, it should be noted that, for ease of description, only the parts related to the present application are shown in the accompanying drawings, not all structures.

[0070] The applicant's research found that most of the existing technologies discuss trajectory tracking control in the infinite time domain. However, in the existing controller designs that meet the convergence performance requirements, the final convergence time is a conservative approximate estimate, but in practical applications, it is often necessary to pre-set a specific convergence time, that is, the existing design methods cannot adapt to practical application needs; in one possible implementation method, a finite time control method can be used. The finite time control method can make the system tracking error converge to a steady state within a finite time, but it has no constraints on transient performance; in one possible implementation method, there is a type of preset performance control of the trajectory. This type of control can simultaneously meet the transient performance and steady-state performance requirements of the trajectory, but it cannot clearly give the time when the system enters a steady state.

[0071] Based on this, the embodiment of the present application provides a designated time control method, device, electronic device and storage medium, in which the displacement vector, velocity vector, target position information and target velocity information of the robot arm are set; the displacement vector, velocity vector, target position information, target velocity information and preset control time are input into the preset time controller, and a control signal is output, the preset time controller is established based on the preset projection strategy and the PD controller, and the preset projection strategy is used to establish a connection between the infinite time domain and the finite time domain; the robot arm is controlled to perform dynamic trajectory tracking according to the control signal. Among them, the progressive stability of the robot arm can be controlled by introducing the target position information and the target velocity information through the PD controller. At the same time, the time in the infinite time domain is mapped to the preset control time in the finite time domain through the preset projection strategy, so as to achieve convergence within the preset control time. In this way, the embodiment of the present application ensures that the control system has fast tracking capability and anti-interference capability while achieving designated time tracking of any dynamic target position information or target velocity information.

[0072] To facilitate understanding of the specific implementation of a specified time control method provided in an embodiment of the present application, the following will be described in conjunction with the accompanying drawings.

[0073] It should be noted that the subject implementing the specified time control method may be a specified time control device provided in the embodiment of the present application, and the specified time control device may be carried in an electronic device or a functional module of an electronic device. The electronic device in the embodiment of the present application may be any device capable of implementing the specified time control method in the embodiment of the present application, for example, an Internet of Things (IoT) device.

[0074] See also Figure 1 , is a flow chart of a designated time control method in an embodiment of the present application. The method can be applied to a designated time control device, which can be such as Figure 7 The device 700 for specifying time control shown in FIG. 1 may also be integrated in the device 700 for specifying time control. Figure 8 Functional modules in the electronic device 800 are shown.

[0075] For example, the following steps may be included:

[0076] S1, set the displacement vector, velocity vector, target position information and target velocity information of the robot arm.

[0077] S2, input the displacement vector, velocity vector, target position information, target velocity information and preset control time into a preset time controller, and output a control signal.

[0078] Among them, the preset time controller is established based on the preset projection strategy and the proportional-derivative (PD) controller. The preset projection strategy is used to establish a connection between the infinite time domain and the finite time domain; the PD controller is a controller used to control the stability and output response speed of the system, which consists of two parts: proportional (P) and differential (D).

[0079] S3, controlling the robot arm to perform dynamic trajectory tracking according to the control signal.

[0080] It should be noted that the dynamic trajectory may generally include a periodic signal, a ramp signal, a step signal or an exponential signal.

[0081] In this way, through the method provided in the embodiment of the present application, the target position information and target speed information are introduced through the PD controller, so as to control the progressive stability of the robot arm. At the same time, the time in the infinite time domain is mapped to the preset control time in the finite time domain through the preset projection strategy, so as to achieve convergence within the preset control time.

[0082] In a possible implementation, the process of obtaining the preset time controller can refer to the design idea diagram of the preset controller shown in 2, see Figure 2 In (a), we first design a PD controller Make the closed-loop response of system (1) asymptotically stable, then construct a set of K-type functions k(·) and M-type functions μ(·) and design a projection strategy, so as to establish the relationship between the infinite time domain and the preset time domain, see Figure 2 In (b), the designed projection strategy and the originally designed PD controller are then substituted into the system (1), and the designed preset time controller is obtained after conversion. The process of obtaining the preset time controller may include the following steps:

[0083] S10, establishing the Lagrangian dynamic equation corresponding to the robotic arm; the Lagrangian dynamic equation is used to describe the motion law of the robotic arm.

[0084] In a possible implementation, the improved S10 in the embodiment of the present application may include: using the second-class Lagrangian method to establish a Lagrangian energy function corresponding to the robot arm; and deriving the Lagrangian energy function to obtain the Lagrangian dynamics equation.

[0085] It should be noted that the Lagrangian energy function is defined as the difference between the total kinetic energy and the total potential energy in the control system where the robot is located, that is, L = K-V. The Lagrangian energy function is used to describe the dynamic state of the control system where the robot is located.

[0086] It should be noted that there may be multiple types of dynamic equations for establishing a control system. The embodiment of the present application uses the second-class Lagrangian method to derive the Lagrangian dynamic equations. Because the second-class Lagrangian method is used to derive the dynamic equations corresponding to the control system, it is only necessary to obtain the kinetic energy and potential energy of the control system, which can reduce the error rate. Of course, other methods can also be used to establish the dynamic equations of the control system, and the embodiment of the present application does not limit this.

[0087] In one possible implementation, the Lagrangian energy function is: Where q is the displacement vector; is the velocity vector, is kinetic energy, P(q) is potential energy; L() is the Lagrangian energy function, K() is the kinetic energy function, and P() is the potential energy function.

[0088] In one possible implementation, the Lagrangian dynamics equation is: Where, M(q)=[M ij ]; M(q)∈R n×n is the inertia matrix, q is the displacement vector, is the velocity vector, is the acceleration vector; is the centrifugal force and Coriolis moment; G(q)∈R n is the gravitational moment; is the resistance torque, u∈R n is the control torque, and n is an integer greater than 1.

[0089] S20, setting the target position information and target speed information of the robot arm according to the control target requirement.

[0090] Among them, the control target is required to achieve target control of the robotic arm so as to control the robotic arm to achieve the progressive stability of target position information and target speed information.

[0091] S30, constructing a PD controller.

[0092] It should be noted that the PD controller is constructed based on the weighted sum of the proportional term and the differential term; the proportional term is the product of the proportional gain and the position error; the differential term is the product of the differential gain and the speed error; the position error is defined based on the actual displacement vector and the target position information; the speed error is defined based on the actual speed vector and the target speed information, and the actual displacement vector and the actual speed vector are obtained based on the Lagrangian dynamic equation.

[0093] Among them, the proportional term is adjusted according to the current error (that is, the deviation between the actual value and the target value), and the proportional gain K p The larger the value, the faster the control output changes. p If it is too large, the control system may oscillate. The differential term is adjusted according to the rate of error change, and the differential gain K d It can reduce the rate of change of system response and thus reduce oscillation. By adjusting the differential of the error, the control system can reach the target value more smoothly.

[0094] In one possible implementation, the control function expression corresponding to the PD controller is: Among them, K p is the proportional gain, K d is the differential gain, q is the actual displacement vector, q d is the target location information, is the actual velocity vector, is the target speed information, [qq d ] represents the position error, Indicates speed error.

[0095] S40, establishing a preset projection strategy according to the time transformation function.

[0096] It should be noted that the time transformation function is used to map the infinite time domain to the finite time domain; the preset projection strategy is used to project the actual displacement vector, the actual velocity vector and the actual acceleration vector to obtain the projected position vector, the projection velocity vector and the projection acceleration vector.

[0097] In one possible implementation, by defining Δt=tt 0 ,η(t)=μ(Δt)+t 0 , the time transformation function μ(·) is introduced. The time transformation function is used to map the original time t to a new time scale η, so as to better process or analyze the dynamic behavior of the robot. In order to improve the convenience of derivation, it is assumed that t 0 =0, then construct the preset projection strategy shown in the following formula (1):

[0098]

[0099] Among them, and p. and They respectively represent the projection position vector, projection velocity vector and projection acceleration vector after projection, t represents the time symbol before projection, and η represents the time symbol after projection.

[0100] S50: constructing a preset time controller according to the preset projection strategy and the PD controller, wherein the preset time controller is used to output a control signal, and the control signal is used to control the robot arm to reach the projection position vector and the projection velocity vector within a preset time.

[0101] In a possible implementation, S50 may include: establishing a projection function based on the time transformation function and the preset projection strategy; constructing a preset time controller according to the projection function and the PD controller;

[0102]

[0103] In formula (2), P and D are both negative definite matrices, k(·) represents the projection function, and the embodiment of the present application selects k(t)=at b / (τ-t) c , where a>0, b>0 and c>0, τ represents a specified time or a preset time, which can produce an increasingly greater control effect when approaching time τ, thereby forcing the control system state to converge quickly to the target state.

[0104] In the embodiment of the present application, the target speed information is introduced into the originally designed PD controller. According to the projection strategy, Projection, that is, if the target position information at time t in the infinite time domain is expressed by q d Indicated by, the projection target position information at time μ(t) in the preset time domain is q d ; If the target speed information at time t in the infinite time domain is expressed as Indicated by, the projection velocity information at time μ(t) in the preset time domain is It can be understood that the position information before and after the projection remains unchanged, and the speed will be scaled proportionally.

[0105] It should be noted that, in order to make the method provided in the embodiment of the present application clearer and easier to understand, a specific example of the method is described below. Assuming that the robotic arm is a two-link robotic arm, a two-link robotic arm refers to a mechanical device composed of two links, then the Lagrangian dynamic equation model of the two-link robotic arm is:

[0106]

[0107] The dynamic parameters of each robot arm are obtained by the following formulas (3) to (10):

[0108] M 11 (q) = 2m 2 l 1 c 1 cos(q 2 )+m 1 (c 1 2 +c 2 2 )+m 2 (l 1 2 +c 2 2 )+I 1 +I 2 Formula (3)

[0109] M 12 (q) = M 21 (q) = m 2 l 1 c 2 sin(q 1 +q 2 )sin(q 1 )+m 2 c 2 2 sin 2 (q 1+q 2 )+I 2 Formula (4)

[0110] M 22 (q) = m 2 c 2 2 sin 2 (q 1 +q 2 )+I 2 Formula (5)

[0111]

[0112]

[0113]

[0114] C 22 (q)=0 Formula (9)

[0115]

[0116] It should be noted that the rod length of the robot arm 1 is denoted by l 1 The length of the rod of robot arm 2 is represented by l 2 Indicated by; the center of gravity of the robot arm 1 is c 1 The center of gravity of robot arm 2 is represented by c 2 Indicated by; the mass of the rod of the robot arm 1 is expressed in m 1 The mass of the rod of robot arm 2 is expressed as m 2 Indicated by; the inertia moment of robot arm 1 is I 1 The moment of inertia of robot arm 2 is represented by I 2 The parameters of the robot arm are shown in Table 1:

[0117] Table 1 Robotic arm parameters

[0118] Rod length Center of gravity Rod quality Moment of inertia Robotic Arm 1 <![CDATA[l 1 =1m]]> <![CDATA[c 1 =1m]]> <![CDATA[m 1 =2kg]]> <![CDATA[I 1 =0.5kg·m 2 ]]> Robotic Arm 2 <![CDATA[l 2 =1m]]> <![CDATA[c 2 =1m]]> <![CDATA[m 2 =2kg]]> <![CDATA[I 2 =0.5kg·m 2 ]]>

[0119] Construct projection function k(t)=at b / (τ-t) c , where a>0, b>0 and c>0.

[0120] In a possible implementation, when the projection function parameters a=20, b=1, c=1, the PD controller parameters P=-[2,0; 0,1], D=-[0.1,0; 0,1], and g are selected 0 =9.81m / s 2 When , the simulation results are as follows Figure 3 and Figure 4 As shown; among them, Figure 3Tracking dynamic target position information q under τ = 15 d1 =3sin(t)+t,q d2 =10ln(t+1), Figure 4 Tracking dynamic target position information q under τ = 15 d1 =sin(t)+0.01t 2 -0.001t 3 ,q d2 =t-0.01t 2 +0.001t 3 .

[0121] It should be noted that from Figure 3 and Figure 4 It can be seen that, given the preset control time τ = 15, the two-link manipulator can track dynamic trajectories such as periodic signals, ramp signals and exponential signals within the preset time, which shows that the proposed preset time controller has good performance.

[0122] In a possible implementation, a dynamic tracking target q is selected d1 =3sin(t)+t and q d2 =10ln(t+1), the controller parameters and dynamic parameters are the same as above, and the relevant experimental results are as follows Figure 5 , Figure 6 See Figure 5 , used to represent the tracking effect comparison diagram when the corresponding preset projection function has different parameters a and the parameters b and c are the same. The dotted line represents the tracking trajectory when a=20,b=c=1, and the solid line represents the tracking trajectory when a=30,b=c=1. Please refer to Figure 6 , used to represent the tracking effect comparison diagram when the parameters b and c in the preset projection function are different and the parameter a is the same. Figure 5 and Figure 6 It can be seen from the figure that when the parameter a is different, the dotted line represents the tracking trajectory when a=20, b=c=1, and the solid line represents the tracking trajectory when a=20, b=c=1.5. When the parameters b and c are the same, the changes in b and c have a greater impact on the dynamic overshoot of the system, and have an impact on the tracking performance of both robot 1 and robot 2; while the change in parameter a has a greater impact on the performance of robot 1 and a smaller impact on robot 2.

[0123] Thus, in an embodiment of the present application, an asymptotically stable PD controller including dynamic target position and velocity information is designed to address the problem of dynamic trajectory tracking. In view of the problem that a specific convergence time cannot be set in advance, a projection strategy is proposed to map the position information and velocity information in an infinite time domain to a preset time domain. The PD controller and the projection strategy are fitted to finally obtain a preset time controller to output a control signal to achieve tracking of the dynamic trajectory within a preset time.

[0124] See also Figure 7 The embodiment of the present application further provides a designated time control device 700, which is applied to a robotic arm, and the device 700 includes:

[0125] An acquisition unit 701 is used to set a displacement vector, a velocity vector, target position information and target velocity information of the robot arm;

[0126] An input unit 702 is used to input the displacement vector, the velocity vector, the target position information, the target velocity information and the preset control time into a preset time controller, and output a control signal, wherein the preset time controller is established based on a preset projection strategy and a PD controller, and the preset projection strategy is used to establish a connection between an infinite time domain and a finite time domain;

[0127] The control unit 703 is used to control the robot arm to perform dynamic trajectory tracking according to the control signal.

[0128] Optionally, the acquiring unit 701 includes:

[0129] A dynamic equation establishment subunit is used to establish the Lagrangian dynamic equation corresponding to the robotic arm; the Lagrangian dynamic equation is used to describe the motion law of the robotic arm;

[0130] A setting subunit, used to set the target position information and target speed information of the robot arm according to the control target requirements;

[0131] A construction subunit is used to construct a PD controller; the PD controller is constructed according to the weighted sum of a proportional term and a differential term; the proportional term is the product of a proportional gain and the position error; the differential term is the product of a differential gain and the speed error; the position error is defined according to an actual displacement vector and the target position information; the speed error is defined according to an actual speed vector and the target speed information; the actual displacement vector and the actual speed vector are obtained according to the Lagrangian dynamic equation;

[0132] A projection strategy subunit, used to establish a preset projection strategy according to a time transformation function; the time transformation function is used to map an infinite time domain to a finite time domain; the preset projection strategy is used to project the actual displacement vector, the actual velocity vector and the actual acceleration vector to obtain a projected projection position vector, a projection velocity vector and a projection acceleration vector;

[0133] A construction subunit is used to construct a preset time controller according to the preset projection strategy and the PD controller, and the preset time controller is used to output a control signal, and the control signal is used to control the robotic arm to reach the projection position vector and the projection velocity vector within a preset time.

[0134] Optionally, the construction subunit is specifically used to:

[0135] Establishing a projection function based on the time transformation function and the preset projection strategy;

[0136] The preset time controller is constructed according to the projection function and the PD controller.

[0137] Optionally, the control function expression corresponding to the PD controller is:

[0138] Among them, K p is the proportional gain, K d is the differential gain, q is the actual displacement vector, q d is the target location information, is the actual velocity vector, is the target speed information.

[0139] Optionally, the kinetic equation establishment subunit is specifically used for:

[0140] A Lagrangian energy function corresponding to the robotic arm is established by using a second-class Lagrangian method, wherein the Lagrangian energy function is defined as the difference between the total kinetic energy and the total potential energy in the control system where the robotic arm is located;

[0141] The Lagrangian energy function is differentiated to obtain the Lagrangian dynamic equation; the Lagrangian energy function is used to describe the dynamic state of the control system where the robotic arm is located.

[0142] Optionally, the Lagrangian energy function is:

[0143]

[0144] Where q is the displacement vector; is the velocity vector.

[0145] Optionally, the Lagrangian dynamic equation is:

[0146]

[0147] Where, M(q)=[M ij ]; M(q)∈R n×nis the inertia matrix, q is the displacement vector, is the velocity vector, is the acceleration vector; is the centrifugal force and Coriolis moment; G(q)∈R n is the gravitational moment; is the resistance torque, u∈R n To control the torque.

[0148] It should be noted that the specific implementation method of the device 700 and the technical effects achieved can be found in Figure 2 The relevant description in the method shown.

[0149] In addition, the present application embodiment also provides an electronic device 800, such as Figure 8 As shown, the electronic device 800 includes a processor 801 and a memory 802:

[0150] The memory 802 is used to store computer programs;

[0151] The processor 801 is used to execute according to the computer program Figure 2 The method provided.

[0152] In addition, an embodiment of the present application further provides a computer-readable storage medium, wherein the computer-readable storage medium is used to store a computer program, and the computer program is used to execute the method provided by the embodiment of the present application.

[0153] Through the description of the above implementation methods, it can be known that those skilled in the art can clearly understand that all or part of the steps in the above-mentioned embodiment method can be implemented by means of software plus a general hardware platform. Based on such an understanding, the technical solution of the present application can be embodied in the form of a software product, which can be stored in a storage medium, such as a read-only memory (ROM) / RAM, a magnetic disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network communication device such as a router) to execute the methods described in each embodiment of the present application or some parts of the embodiments.

[0154] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. The device embodiment described above is only schematic, in which the modules described as separate components may or may not be physically separated, and the components displayed as modules may or may not be physical modules, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules can be selected according to actual needs to achieve the goals of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative work.

[0155] The above is only a preferred embodiment of the present application and is not intended to limit the protection scope of the present application. It should be noted that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the present application, and these improvements and modifications should also be regarded as the protection scope of the present application.

Claims

1. A designated time control method, characterized in that: Applied to a robotic arm, the method comprises: Setting the displacement vector, velocity vector, target position information and target velocity information of the robotic arm; Input the displacement vector, the velocity vector, the target position information, the target velocity information and the preset control time into a preset time controller, and output a control signal, wherein the preset time controller is established based on a preset projection strategy and a PD controller, and the preset projection strategy is used to establish a connection between an infinite time domain and a finite time domain; The robot arm is controlled to perform dynamic trajectory tracking according to the control signal.

2. The method according to claim 1, characterized in that The process of obtaining the preset time controller includes: Establishing the Lagrangian dynamic equation corresponding to the robotic arm; the Lagrangian dynamic equation is used to describe the motion law of the robotic arm; According to the control target requirements, the target position information and target speed information of the robot arm are set; Constructing a PD controller; the PD controller is constructed according to the weighted sum of a proportional term and a differential term; the proportional term is the product of a proportional gain and the position error; the differential term is the product of a differential gain and the speed error; the position error is defined according to an actual displacement vector and the target position information; the speed error is defined according to an actual speed vector and the target speed information; the actual displacement vector and the actual speed vector are obtained according to the Lagrangian dynamic equation; Establishing a preset projection strategy according to a time transformation function; the time transformation function is used to map an infinite time domain to a finite time domain; the preset projection strategy is used to project the actual displacement vector, the actual velocity vector and the actual acceleration vector to obtain a projected position vector, a projected velocity vector and a projected acceleration vector; According to the preset projection strategy and the PD controller, the preset time controller is constructed, and the preset time controller is used to output a control signal, and the control signal is used to control the robotic arm to reach the projection position vector and the projection velocity vector within a preset time.

3. The method according to claim 2, characterized in that The step of constructing a preset time controller according to the preset projection strategy and the PD controller comprises: Establishing a projection function based on the time transformation function and the preset projection strategy; The preset time controller is constructed according to the projection function and the PD controller.

4. The method according to claim 2, characterized in that: The control function expression corresponding to the PD controller is: Among them, K p is the proportional gain, K d is the differential gain, q is the actual displacement vector, q d is the target location information, is the actual velocity vector, is the target speed information.

5. The method according to claim 2, characterized in that: The Lagrangian dynamic equation corresponding to the robotic arm is established, including: A Lagrangian energy function corresponding to the robotic arm is established by using a second-class Lagrangian method, wherein the Lagrangian energy function is defined as the difference between the total kinetic energy and the total potential energy in the control system where the robotic arm is located; The Lagrangian energy function is differentiated to obtain the Lagrangian dynamic equation; the Lagrangian energy function is used to describe the dynamic state of the control system where the robotic arm is located.

6. The method according to claim 5, characterized in that The Lagrangian energy function is: Where q is the displacement vector; is the velocity vector.

7. The method according to claim 5, characterized in that The Lagrangian dynamic equation is: in, is the inertia matrix, q, q is the displacement vector, is the velocity vector, is the acceleration vector; is the centrifugal force and Coriolis moment; G(q)∈R n is the gravitational moment; is the resistance torque, u∈R n To control the torque.

8. A designated time control device, characterized in that: Applied to a robotic arm, the device comprises: An acquisition unit, used for setting a displacement vector, a velocity vector, target position information and a target velocity information of the robotic arm; An input unit, used to input the displacement vector, the velocity vector, the target position information, the target velocity information and the preset control time into a preset time controller, and output a control signal, wherein the preset time controller is established based on a preset projection strategy and a PD controller, and the preset projection strategy is used to establish a connection between an infinite time domain and a finite time domain; A control unit is used to control the robotic arm to perform dynamic trajectory tracking according to the control signal.

9. An electronic device, characterized in that: The electronic device comprises a processor and a memory: The memory is used to store computer programs; The processor is configured to execute the method according to any one of claims 1 to 7 according to the computer program.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium is used to store a computer program, and the computer program is used to execute the method according to any one of claims 1 to 7.

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