CONSTANT GAP AND MINIMUM ENERGY SUPPLY CONTROL FOR A PROPORTIONAL PNEUMATIC FLOATING VACUUM PAD

In this paper, a new proportional pneumatic floating vacuum pad is developed and constructed. There are two features concerning this new vacuum pad. The first one is the introduced proportional solenoid, which enables the continuously variable control of the suction force output. In addition, the floating mechanism design between the vacuum pad and work-piece is the second feature, which is more preferable in real industries because it can protect the surface of the work-piece from scratching or other damages. Moreover, two control schemes are also proposed in this paper. The first one is the gap control. A pre-set constant gap is input to the controller as the command input which further drives the proportional solenoid to maintain a steady-state gap between the vacuum pad and work-piece. In the second control approach, the gap between the vacuum pad and work-piece is kept as large as possible to minimize the energy consumption. Both control schemes are successfully implemented in this study. It is expected that the newly developed prototype with two different control schemes may find some real applications in the future.