Optimal high-bandwidth control of ball-screw drives with acceleration and jerk feedback

This paper presents an optimal non-collocated control strategy for flexible ball-screw feed drives. Within the non-collocated controller framework, all the feedback measurements are taken from table (load) side. The table acceleration and jerk feedback measurements are used to control both rigid body and the structural dynamics, which enables modal damping capability. Linear quadratic regulator (LQR) framework is then utilized to achieve optimal placement of the poles. State based LQR weights are mapped to frequency domain performance targets, i.e. crossover frequency and phase margin, and hence a novel frequency domain optimal tuning strategy is achieved. A kinematic state observer design is also presented to fuse analog accelerometer measurements with linear encoder feedback to realize high-fidelity state feedback and wide bandwidth motion control. Finally, robustness analysis of non-collocated control is carried out, and comparison against conventional full closed-loop collocated controllers is presented. Comprehensive experimental validations and performance benchmarks are conducted on an industrial scale precision ball-screw driven motion stage.