大惯量专用转台高精度控制研究

针对大惯量专用转台运行过程中存在的系统响应时间长、易产生振荡以及末端位置定位误差较大的问题,提出了一种基于全闭环+模糊自适应PID(proportion integral differential,比例积分微分)的精度控制方法。在大惯量专用转台执行机构处加入多圈绝对式编码器,以实现控制系统的全闭环;利用模糊自适应PID控制实现不同负载下高精度控制系统的快速调节。为更加深入研究大惯量对专用转台控制系统的影响,对转台进行了系统建模;同时在MATLAB仿真环境中分别建立了基于模糊自适应PID控制和普通PID控制的转台控制系统仿真模型,并搭建了转台测试平台进行验证实验。对比不同控制方式下系统控制性能的仿真结果可知:普通PID控制系统响应时间长,系统跟随误差大;而使用模糊自适应PID控制可使系统的响应速度提高75%,跟随误差降低降低70%。由实验结果可知专用转台定位精度为-0.2°,0.2°],满足了设计精度要求。仿真和实验结果表明利用模糊自适应PID控制可有效提高系统的响应速度,全闭环控制可使系统的定位精度得到有效提高。研究结果为转台控制系统的设计提供了有效的参考数据,促进了大惯量转台的高精度化发展。

Research on high precision control of large inertia special turntable

In the process of running a large inertia special turntable, the system has some problems such as long response time, easy oscillation and large positional error at the end position, so a method based on full-closed loop + fuzzy adaptive PID (proportion integration differentiation) control is proposed. The multi-turn absolute encoder was added at the actuator of large inertia special turntable to achieve full-closed loop of the control system; the fuzzy adaptive PID control was used to achieve fast adjustment under different loads. In order to study the influence of large inertia on the control system further, a turntable model was established systematically. Turntable control system simulation models based on fuzzy adaptive PID control and common PID control were set up respectively in the MATLAB simulation environment, and turntable test platform was built for verification experiment.Comparing the simulation results of system control performance under different control methods, the common PID control system had a long response time and the system followed the error. The fuzzy adaptive PID control could increase the system response speed by 75% and the system’s following error reduced by 70%. The experimental results showed that the positional accuracy of the special turntable was -0.2°, 0.2°], which satisfied the design accuracy requirement. By analyzing the simulation results and experimental results, the fuzzy adaptive PID control can effectively improve the system response speed, and the full closed-loop control also can effectively improve system positioning accuracy. The research result provides effective reference data for the design of the turntable control system and promotes high-precision development of large inertia turntable.