US 12,228,890 B2
Method and apparatus for precise control of position of servo motor based on space-time two-dimensional optimization
Bitao Zhang, Guangzhou (CN)
Assigned to Guangdong Polytechnic Normal University, Guangzhou (CN)
Filed by Guangdong Polytechnic Normal University, Guangzhou (CN)
Filed on Mar. 14, 2024, as Appl. No. 18/605,523.
Claims priority of application No. 202310761407.5 (CN), filed on Jun. 27, 2023.
Prior Publication US 2025/0004427 A1, Jan. 2, 2025
Int. Cl. G05B 11/42 (2006.01)
CPC G05B 11/42 (2013.01) 5 Claims
OG exemplary drawing
 
1. A method for precise control of a position of a servo motor based on space-time two-dimensional optimization comprising the following steps:
targeting either one of an angle or a displacement of the servo motor as a target value;
obtaining a set value and a feedback value of the target value;
based on the set value and the feedback value of the target value, performing processing by a control algorithm integrating a time dimension and a space dimension to obtain an output of the target value at a time t in a k dimension;
wherein specifically, based on the set value and the feedback value of the target value, performing processing by the control algorithm integrating the time dimension and the space dimension to obtain the output of the target value at the time t in the k dimension comprises:
performing processing by the control algorithm in the time dimension, including:
defining e(t) as a following error of the target value,
e(t)=Pr(t)−P(t)  (1)
wherein Pr(t) is the set value of the target value, and P(t) is the feedback value of the target value;
calculating a control rate rk(t) at the time t in the k dimension based on the following error e(t) of the target value and a state deviation δ(xk(t)) of the target value at the t time in the k dimension and a k−1 dimension,

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wherein a control rate gain is defined by a two-dimensional matrix Kp=k1, k2),
δ(xk(t))=xk(t)−xk-1(t)  (3)
xk(t) is a state of the target value at the time t in the k dimension, and xk-1(t) is a state of the target value at the time t in the k−1 dimension, which are read by a memory, and the memory is used for storing a state value and an output value of the previous dimension;
performing processing by the control algorithm in the space dimension, including:
calculating an output uk(t) of a controller at the time t in the k dimension;
uk(t)=uk-1(t)+rk(t)  (4)
wherein uk-1(t) is an output of the controller at the time t in the k−1 dimension, and is read by the memory,
inputting uk(t) into a motor mechanism model Σs to obtain an output Pk(t) of the target value at the time t in the k dimension,

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wherein A, B, and C are electrical coefficients of the servo motor, ΔA(t) and ΔB(t) are changes in the electrical coefficients of the servo motor: d(t) is an external disturbance; and Tp represents an operating cycle time of the servo motor in the space dimension, using the simultaneous equations (1)-(4), an output uk(t) of the controller of the servo motor is calculated, and the target value of the servo motor is controlled to follow the set value, and
performing control of the servo motor based on a calculated output of the target value at the time t in the k dimension.