基于Simulink电液比例位置控制系统的性能分析和优化

Performance Analysis of Electro-Hydraulic Proportional Control System Based on Simulink

为改善某钢铁公司电液比例位置控制系统相关系统性能,文章使用数值计算分析方法,建立电液比例位置控制系统的数学模型,通过Simulink软件构建模型,并分析可知,系统的幅值裕度为25 dB,相位裕度为89.6°,结合伯德图的曲线特征,发现该系统的准确性与稳定性已满足基本要求,但通过系统的阶跃响应曲线,发现其上升时间为4.26 s、调整时间为5.83 s,系统响应的快速性没有达到要求。为进一步改进系统性能,选取结构简单、适用范围广的PID控制器,通过添加PID控制和不断修改PID控制器参数,优化系统性能,优化后的系统幅值裕度为5.18 dB,相位裕度90°,上升时间为0.236 s,调整时间为0.435 s,系统在保持良好的准确性和稳定性的基础上,快速性也得到了改善,已完全满足工业生产的要求。最后讨论了液压缸有效面积对PID控制性能的影响:A_(h)=0.15~0.20 m^(2)时系统性能仍有较好的适用性;小于0.15 m^(2)时会发生剧烈震动;大于0.20 m^(2)会大大增加响应时间。

In order to improve the performance of the relevant system of the electro-hydraulic proportional position control system of a steel company,the mathematical model of the electro-hydraulic proportional position control system was first established by using numerical calculation and analysis method,and the model was constructed with Simulink software.Through analysis,the amplitude margin of the system was 25 dB and the phase margin was 89.6°.It is found that the accuracy and stability of the system have met the basic requirements,but through the step response curve of the system,it is found that the rise time is 4.26 s and the adjustment time is 5.83 s,and the rapidity of the system response does not meet the requirements.In order to further improve the performance of the system,the PID controller with simple structure and wide application range is selected in this paper.By adding PID control and constantly modifying PID controller parameters,the performance of the system is optimized.The final optimized system amplitude margin is 5.18 dB,and the phase margin is 90°.The rise time is 0.236 s,the adjustment time is 0.435 s,the system in maintaining good accuracy and stability on the basis of speed has been improved,has fully met the requirements of industrial production.Finally,the effect of the effective area of the hydraulic cylinder on the PID control performance is discussed.When the effective area of the hydraulic cylinder is A_(h)=0.15~0.20,the system performance still has good applicability;when it is less than 0.15,severe vibration will occur,and when it is greater than 0.20,the response time will be greatly increased.This analysis provides some reference for the subsequent scholars to adjust the PID parameters.