基于PLC控制的电子凸轮系统设计

Design of electronic cam control system based on PLC

针对机械凸轮为高副接触(点或线),存在压强较大、易磨损、有噪声、凸轮轮廓加工比较困难等特点,设计了电子凸轮方案,对凸轮的运动特性、曲线规律、电机调速、伺服控制等方面进行了研究,提出了基于三菱Q系列可编程逻辑控制器(PLC)控制的电子凸轮系统。利用双CPU伺服控制,同时处理顺序控制和运动控制,提高了其控制精度与控制效率。采用了闭环控制模式的伺服控制系统,由位置编码器计算出伺服电机的位置、速度等控制指令,模拟出了凸轮轨迹的效果,实现了推杆往复运动。同时制作了机械凸轮结构,连接推杆做往复运动,与电子凸轮推杆运动作了对比。研究结果表明,该电子凸轮系统方案可实现推杆的各类往复运动规律,控制精度及反应速度较好;且通过调整电子凸轮输入曲线,可以达到完全替代机械凸轮的效果。

Aiming at the disadvantages of conventional mechanical cam： points or lines contact, highpressure, easy to wear, noise, difficult to machine, an electronic cam was designed. The cam motion characteristics, motion curve, motorcontrol, servo control was studied, a design of electronic cam control system based on Mitsubishi Q series PLC was proposed with double CPU servo control, which can deal with the sequential control and motion control, the control precision and control efficiency was improved. A closed loop control mode was employed. The servo-motor＇s position and speed instructions were calculated by the position encoder, which drive the push rod move straightly back and forth. At the same time, as a comparison with electronic cam, a mechanical cam structure was maded. The experiment results indicate that any kinds of reciprocating motion can be gained by using the electronic cam. By adjusting the input curve of electronic cam, the effect of completely replacing the mechanical cam can be realized.