液压比例系统特性分析与非对称控制策略

Characteristic analysis of hydraulic proportional system and asymmetric control strategy

建立了非零开口的比例阀控非对称液压系统数学模型,分析了外负载和结构参数变化对系统负载流量的影响,得到了非对称系统负载流量特性曲线,提出了非对称控制策略,具体通过对液压缸不同运动方向或者同向不同负载情况时设置不同的最大流量、最小流量、比例放大系数和参考输入以实现液压缸速度基本一致.实验对比了有无非对称控制策略的系统速度响应情况,结果表明:采用非对称控制策略能有效地提高速度响应的一致性,响应时间均在0.2s内,误差小于0.002m/s.并将非对称控制策略应用于大型挤压机节流调速系统,实现了节流调速系统正反方向速度特性基本一致.实验和应用结果表明了特性分析的正确性和非对称控制策略的有效性.

The mathematics model of asymmetric hydraulic proportional system with nonzero lap was built.The characteristic of the system under the change of load and asymmetric structure was analyzed.An asymmetric load flow characteristic curve was obtained.An asymmetric control strategy was put forward according to load flow curve.According to cylinder move forward and reverse,the maximum flow,minimum flow,reference input and proportional amplification coefficience were designed differently.The speed response experiment was carried out with and without asymmetric control strategy.The results show that the speed consistent is improved with the asymmetric control strategy.The speed response time is less than 0.2s,and speed error less than 0.002m/s.The throttle system of large scale extruder speed consistent was realized by using asymmetric control strategy and the correctness of the modeling and analysis and the effective of control strategy by the experiment results and industry application was proved.