Effect of downward depth and inflation pressure on contact force of gasbag polishing

- A coupling contact force model is built based on the experimental monitoring data.
- The prediction of inflation pressure can help to get the optional combination and controllable range of polishing contact force.
- The steady-state error of the coupling contact force control system is no more than 2 N.
- The polishing uniformity and quality of the mold surface is improved effectively.

Gasbag polishing is a kind of ultra-precision machining technology by means of flexible contact, while how to control the polishing contact force online is one of the key issues. In this paper, by analyzing the effect of downward depth and inflation pressure on the contact force experimentally, and then the coupling contact force model is developed. Thus, the predictions of polishing contact force and inflation pressure in terms of the nonlinear composite material of rubber gasbag can be obtained, which can be used to get the optional combination and controllable range of polishing contact force, and to construct the control system of coupling contact force as well. Experimental study shows that applying coupling contact force model to the control system of gasbag polishing contact force with BP neural network PID control strategy is a proper method, which realizes the polishing contact force controllable online and uniform surface quality of mold.