基于模糊PID的变幅液压控制系统

Variable Amplitude Hydraulic Control System Based on Fuzzy PID

针对高空带电机器人作业时出现臂架振动和抖动的问题,设计了基于模糊PID控制器的闭环液压控制系统。以液压缸活塞杆速度的误差和误差变化率为输入变量,经过模糊化、模糊推理、解模糊的方式来动态调节活塞杆的速度,使其达到稳定状态。以高空带电机器人的臂架变幅液压系统为研究对象,通过建立液压平衡回路数学模型得到系统的传递函数,在MATLAB/Simulink环境内搭建模糊PID和经典PID的控制方案仿真模型,并搭建试验平台进一步验证。结果表明:与经典PID控制相比较,模糊PID控制的响应滞后时间由0.55 s降到了0.2 s,缩短了63.6%,最大超调量由0.09 m降到了0.01 m,相对降低了88.9%,稳定时间由2.4 s缩短至0.4 s,相对降低了83.3%;另外实验结果为模糊PID控制下的系统响应滞后时间相对于经典PID缩短了0.2 s,超调量降低了0.032 m,稳定时间缩短了1.7 s,跟仿真结果相一致。实验数据表明,模糊PID控制器有效地解决了臂架振动和抖动问题,提高了臂架运动控制的稳定性。

In order to solve the problem of boom vibration and jitter,This paper designs a closed-loop hydraulic control system based on Fuzzy PID controller.Taking the velocity error and its change rate of piston rod of hydraulic cylinder as input variables,the velocity of piston rod is dynamically adjusted by means of fuzzing,fuzzy reasoning and solving fuzziness,so that it can reach a stable state.In this paper,the boom luffing hydraulic system of high-altitude electrified robot is taken as the research object.The transfer function of the system is obtained by establishing the mathematical model of hydraulic balance circuit.The simulation model of fuzzy PID and classic PID control scheme is built in MATLAB/Simulink environment,and the test platform is built for further verification.The simulation results show that compared with the classical PID control,the response lag time of fuzzy PID control is reduced from 0.55 s to 0.2 s,which is 63.6%shorter;the maximum overshot is reduced from 0.09 m to 0.01 m,which is 88.9%lower;the stability time is reduced from 2.4 s to 0.4 s,which is 83.3%lower.In addition,the experimental results show thatthe lag time for the system response under the fuzzy PID control is reduced by 0.2 s,the overshot is reduced by 0.032 m,and the stability time is reduced by 1.7 s,which is consistent with the simulation results.Experimental data show that the fuzzy PID controller can effectively solve the vibration and jitter problems of the boom and improve the stability of the boom motion control.