基于滑模控制的气动伺服焊枪软接触研究

Soft Contact of Pneumatic Servo Gun Based on Sliding Mode Control

为了提高电阻点焊过程的焊接效率,避免电极接近时过大的冲击力对焊件造成损坏,通过分析焊枪电极的碰撞机理,提出了气动伺服焊枪的软接触指标。利用分段滑模控制的方法对点焊过程的渐进阶段进行控制,同时提出了最优缓冲距离的概念。通过实验比较了PID控制、滑模变结构控制和分段滑模变结构控制方法的缓冲效果。实验结果表明,分段滑模变结构控制在保证加载过程时间较短的基础上,能有效地减小焊枪电极对焊件的冲击,基本实现了提出的技术指标,该方法具有一定的应用价值。

In order to improve the welding efficiency of resistance spot welding process and prevent the large impact force damaging the weldment when the electrode approaches, we provide the soft contact index of pneumatic servo gun through analyzing the collision mechanism of electrodes in this study. The gradual stage of the spot welding process is controlled by the method of subsection sliding mode control. At the same time, the concept of the optimal buffer distance is put forward. The buffer effects of PID control, sliding mode variable structure control and subsec- tion sliding mode variable structure control are compared by experiments. The experimental results show that the subsection sliding mode variable structure control can effectively reduce the impact of the electrode of the welding gun on the weldment on the basis of ensuring the short loading study are basically realized. This method has certain application time, and the technical indexes proposed in this value.