Synchronizing dual-drive gantry of chip mounter with LQR approach

The present paper deals with the development of synchronizing controller for a dual-drive servo system that is often used for high speed and precision gantry system. The dual-drive mechanism has been used to increase the system bandwidth of precision gantry systems. This work is achieved by the evaluation of an synchronizing control with LQR scheme aimed specifically at improving synchronous accuracy in dual feed drives. The performance index for the optimal control formulation explicitly includes the synchronizing errors both in position and velocity, which is to be minimized. An assembly machine for surface mount devices is used for simulations and experiments. The system is modeled as the first order approximation and cross-coupled optimal synchronizing controller is designed. The design parameters are obtained by multi-variable frequency domain analysis. Simulations and experiments are carried about various gains and mismatched dynamics. The results show that the proposed controller reduces the synchronous error considerably, compared to the conventional uncoupled control for the dual-drive system.