WU Haoyu, GU Lichen, GENG Baolong, LIU Jiamin, ZHAO Baojian, YANG Sha
（School of Mechatronic Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, China）
Abstract： For variable speed pump-controlled hydraulic cylinder system, the nonlinear change of hydraulic system parameters is brought in by large-scale change of speed or load. It causes the control system, which is designed by the linear model, to have the problems such as difficult correction of control parameters, unstable precision or even control instability. In this paper, a multi-model adaptive PID (MMA-PID) control method is proposed by analyzing the state space of a typical variable speed pump-controlled hydraulic cylinder system. According to the nonlinear change of the bulk elastic modulus of oil caused by the change of the system pressure, the system behavior is described by using multiple linear sub-models. A reasonable controller is designed for each sub-model. During the control process, the output weight coefficient of each sub-model is estimated separately through the Kalman filter, and the weighted fusion of all the sub-models control output is used as the final control input of the system. The simulation and experimental results demonstrate that when the working conditions are vary widely, the MMA-PID can adapt to the nonlinear change of system parameters better than the traditional PID, and it owns better control effect and dynamic performance.
Key words： variable speed pump-controlled hydraulic cylinder; state space; nonlinear parameter; Kalman filter; multi-model adaptive PID (MMA-PID)
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变转速泵控液压缸系统的多模型自适应PID控制
仵浩宇， 谷立臣， 耿宝龙， 刘佳敏， 赵宝建， 杨莎
（西安建筑科技大学 机电工程学院， 陕西 西安 710055）
摘要：变转速泵控液压缸系统转速或负载大范围变动导致的液压系统参量非线性变化， 可使基于线性模型设计的控制系统出现控制参数不合理、 精度不稳定， 甚至控制失稳等问题， 本文通过分析典型变转速泵控液压缸系统的状态空间， 提出了一种多模型自适应PID （Multi-model adaptive PID, MMA-PID）控制方法。 该方法根据系统压力的改变引起的油液体积弹性模量的非线性变化， 用多个线性子模型分别描述系统行为， 并针对每个子模型， 单独设计一个合理的控制器。 控制过程中， 通过卡尔曼滤波器分别估计各个子模型的输出权重系数， 并将所有子模型控制输出加权融合作为系统最终的控制输入。 仿真和实验结果表明， 在工况大范围变化时， 多模型自适应PID控制相较于传统的PID控制， 能更好的适应系统参量的非线性变化， 具有更好的控制效果和动态性能。
关键词：变转速泵控液压缸； 状态空间； 非线性参量； 卡尔曼滤波器； 多模型自适应PID
引用格式：WU Haoyu, GU Lichen, GENG Baolong, et al． Multi-model adaptive PID control of variable speed pump-controlled hydraulic cylinder system． Journal of Measurement Science and Instrumentation， 2023， 14（2）： 209-217. DOI： 10．3969／j．issn．1674-8042．2023．02．010
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