大型液压成形装备快降运动曲线的平稳性设计与控制

Design and Control of the Motion Curve for the Rapidly Falling of the Large-Tonnage Hydraulic Forming Equipment

大型液压成形装备活动横梁快降过程中存在较强的时变性和非线性特点,带来运行过程的冲击和振动问题,严重影响工艺成形质量。针对现有快降控制技术存在的问题,分析活动横梁快降时液压系统的动力学特点,提出基于五次曲线的快降运动规律设计方法。以平均速度最大与冲击最小为约束,采用NSGA-II算法求解最优运动曲线,开发了基于模糊PID的运动曲线跟踪控制策略。通过仿真和实验研究,验证了快降运动曲线设计与控制的有效性,结果表明:活动横梁运动过程中的冲击得到了有效缓解,降低幅度达21%。

The impact and vibration issues caused by strong time-varying and non-linear characteristics during the rapidly falling operation of large-tonnage hydraulic forming equipment,will seriously affect the forming quality of the process.According to the problems in the existing rapidly falling control technology,the dynamic characteristics of the hydraulic system were analyzed,and the design method of rapidly falling motion law based on the quintic curve was proposed.Constrained with the maximum average velocity and the minimum impact,NSGA-II algorithm was used to solve the optimal motion curve and develop a control strategy of motion curve tracking based on fuzzy PID.The effectiveness of design and control of the motion curve for the rapidly falling were validated by simulation and experiments.The results show that the impact during moving cross member movement is effectively reduced by 21%.