A voltage control method for a single joint of a robot

Abstract

The present invention proposes a robot single joint voltage control method, comprising: setting an outer loop control mode and an inner loop control mode for the single joint voltage control mode of the robot, wherein the outer loop control mode is used for dynamic calculation, and the inner loop control mode is used for voltage control; calculating the outer loop control quantity θ md ; The outer loop control quantity θ md It is transmitted to the inner loop and the inner loop motor voltage control quantity u(t) is calculated; the calculated inner loop motor voltage control quantity u(t) is input into the servo motor to realize voltage control.

Description

Technical Field

[0001] The invention relates to the technical field of industrial robots, and in particular to a robot single-joint voltage control method. Background Art

[0002] With the continuous expansion of the application fields of industrial robots and the rapid development of modern industry, people have higher and higher requirements on the performance of industrial robots in order to further improve production efficiency and product quality. Therefore, high speed and high precision have become the current development trend of robot control.

[0003] However, robot control currently still faces some important challenges, because the robot is a strongly nonlinear, strongly time-varying, and strongly coupled system, and there are many uncertainties in the system modeling process, such as external disturbances, the establishment and changes of system parameters, etc.

[0004] At present, robots mainly use the traditional three-loop PI control method of single-joint servo. This method is the most commonly used control method. It does not require a control model and achieves the command target by correcting the deviation. However, due to the flexibility of the robot's single joint, it will produce large position errors and torque errors, unexpected transitions, and even affect the stability of the system. Therefore, the high speed and high precision of the robot's single joint are still challenges facing modern robot control. Summary of the invention

[0005] The object of the present invention is to solve at least one of the technical drawbacks.

[0006] To this end, the purpose of the present invention is to provide a robot single joint voltage control method.

[0007] In order to achieve the above object, an embodiment of the present invention provides a robot single joint voltage control method, comprising the following steps:

[0008] Step S1, setting an outer loop control mode and an inner loop control mode for a single joint voltage control mode of the robot, wherein the outer loop control mode is used for dynamic calculation, and the inner loop control mode is used for voltage control;

[0009] Step S2, calculate the outer loop control variable θ md ;

[0010] Step S3: the outer loop control variable θ md It is passed to the inner loop and the inner loop motor voltage control quantity u(t) is calculated;

[0011] Step S4, inputting the calculated inner loop motor voltage control variable u(t) into the servo motor to achieve voltage control.

[0012] Further, in step S2, the outer loop control amount θ is calculated by dynamicsmd ,include:

[0013]

[0014] f(t)=k(e)e(t)

[0015] k(e)=K0+K1{I n -sech(e)}

[0016] in:

[0017] e(t)=θ d -θ

[0018]

[0019] Among them, θ d : Target motor position; K p ,K d ,K I : adjustable parameters, diagonal matrix composed of the position loop PID control parameters of each joint; K0, K1: adjustable parameters, diagonal matrix; θ is the actual position of the connecting rod end; the robot has n joints, I n is the n-order unit matrix; e i is the connecting rod end position of joint i.

[0020] Further, in step S3, the outer loop control amount θ md It is passed to the inner loop and the inner loop motor voltage control quantity u(t) is calculated, including:

[0021]

[0022] Where: β is an adjustable parameter, a diagonal matrix, R is the resistance, I a is the phase A current, K b is the motor voltage control parameter, i.e., the voltage to speed ratio, and E is the difference between the target motor position and the actual motor position; is θ md The differential of .

[0023] According to the robot single joint voltage control method of the embodiment of the present invention, the joint flexibility is taken into consideration and the design is applied to the robot position control, and the control accuracy and stability of the system are improved through the voltage control strategy. Specifically, the present invention reduces the dependence on system parameters and improves the system control accuracy through non-model control, and after integration, the bandwidth and stability of the system are significantly improved.

[0024] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0026] Figure 1 4 is a flow chart of a robot single joint voltage control method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0027] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0028] like Figure 1 As shown, the robot single joint voltage control method according to the embodiment of the present invention comprises the following steps:

[0029] Step S1, for the single joint voltage control mode of the robot, set the outer loop control mode and the inner loop control mode respectively, wherein the outer loop control mode is used for dynamic calculation, and the inner loop control mode is used for voltage control. Among them, in motor control, the motor is divided into three loops for control, and the control quantity is calculated by the outer loop and passed to the next loop, which is generally called the inner loop. Here, there are only two loops, so they are called the outer loop and the inner loop. The outer loop: used for dynamic calculation; the inner loop: used for voltage control.

[0030] Step S2, calculate the outer loop control variable θ md .

[0031] Specifically, the outer loop control quantity θ is calculated by dynamics md ,include:

[0032]

[0033] f(t)=k(e)e(t)

[0034] k(e)=K0+K1{I n -sech(e)}

[0035] in:

[0036] e(t)=θ d -θ

[0037]

[0038] Among them, θ d : Target motor position; K p ,K d ,K I: adjustable parameters, diagonal matrix composed of the position loop PID control parameters of each joint; K0, K1: adjustable parameters, diagonal matrix; θ is the actual position of the connecting rod end; the robot has n joints, I n is the n-order unit matrix; e i is the connecting rod end position of joint i.

[0039] Step S3: set the outer loop control variable θ md It is passed into the inner loop and the inner loop motor voltage control quantity u(t) is calculated.

[0040] Specifically, the outer loop control quantity θ md It is passed to the inner loop and the inner loop motor voltage control quantity u(t) is calculated, including:

[0041]

[0042] Where: β is an adjustable parameter, a diagonal matrix, R is the resistance, I a is the phase A current, K b is the motor voltage control parameter, i.e., the voltage to speed ratio, and E is the difference between the target motor position and the actual motor position; is θ md The differential of .

[0043] Step S4, inputting the calculated inner loop motor voltage control variable u(t) into the servo motor to achieve voltage control.

[0044] According to the robot single joint voltage control method of the embodiment of the present invention, the joint flexibility is taken into consideration and the design is applied to the robot position control, and the control accuracy and stability of the system are improved through the voltage control strategy. Specifically, the present invention reduces the dependence on system parameters and improves the system control accuracy through non-model control, and after integration, the bandwidth and stability of the system are significantly improved.

[0045] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0046] Although the embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and cannot be understood as limiting the present invention. Those skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A robot single joint voltage control method, characterized in that: The steps include: Step S1, setting an outer loop control mode and an inner loop control mode for a single joint voltage control mode of the robot, wherein the outer loop control mode is used for dynamic calculation, and the inner loop control mode is used for voltage control; Step S2, calculate the outer loop control variable θ md ; Among them, the outer loop control quantity θ is calculated by dynamics md ,include: f(t)=k(e)e(t) k(e)=K0+K1{I n -oneself} in: e(t)=θ d -θ Among them, θ d : Target motor position; K p ,K d ,K I : adjustable parameters, diagonal matrix composed of the position loop PID control parameters of each joint; K0, K1: adjustable parameters, diagonal matrix; θ is the actual position of the connecting rod end; the robot has n joints, I n is the n-order unit matrix; e i is the connecting rod end position of joint i; Step S3: the outer loop control variable θ md It is passed to the inner loop and the inner loop motor voltage control quantity u(t) is calculated, including: Where: β is an adjustable parameter, a diagonal matrix, R is the resistance, I a is the phase A current, K b is the motor voltage control parameter, i.e., the voltage to speed ratio, and E is the difference between the target motor position and the actual motor position; is θ md The differential of Step S4, inputting the calculated inner loop motor voltage control variable u(t) into the servo motor to achieve voltage control.

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