https://pure.tue.nl/ws/files/4362785/614692.pdf

Trajectory planning and feedforward design for electromechanical motion systems

In this paper, effort is devoted to point-to-point motion control for the high-acceleration positioning table driven by linear motors. New performance indices for point-to-point motion are first introduced. Then, a cascaded controller is designed. It consists of an inner loop velocity PI controller and an outer loop position P plus A-type iterative learning controller. In the subsequence, the convergence analysis in both time and frequency domains is given. The control strategy has the property that only the position signal is required in the outer loop. With the common motion profiles, i.e., T-curve and S-curve, and partial knowledge of the system, point-to-point motion experiments are carried out. The maximum acceleration of the motion profile is 0.04 (about 4.07 g), and the maximum velocity is 0.4 mm/ms. Experimental results illustrate that the proposed controller can greatly improve the performance, and the S-curve motion profile has advantages over the T-curve one.

Point-to-Point Motion Control for a High-Acceleration Positioning Table via Cascaded Learning Schemes

This paper considers model-based feedforward for motion systems The proposed feedforward controller consists of an acceleration feedforward part and an inverse dynamics model of flexible modes Based on analysis and H/sub /spl infin// model-based feedforward design, the inverse dynamics can be restricted to a second order filter in the form of a skew notch even if the motion system has more parasitic modes The benefit of this is an on-line tuning possibility Tracking errors and settling times can be reduced significantly compared to acceleration feedforward

/pdf/model-based-feedforward-for-motion-systems-4010qxzeuh.pdf

Model-based feedforward for motion systems

This paper considers a general class of linear iterative learning control (ILC) algorithm applied to tracking tasks which require the plant output to reach given points at predetermined time instants, without the specification of intervening reference points. A framework is developed in the frequency-domain in which the reference is updated between trials. It is shown that superior convergence and robustness properties are obtained compared with those associated with using the original class of ILC algorithm to track a prescribed arbitrary reference trajectory satisfying the point-to-point output constraints. Experimental results using a non-minimum phase test facility are presented to illustrate the theoretical findings.

/pdf/iterative-learning-control-for-multiple-point-to-point-uyp3nb89i2.pdf

Iterative Learning Control for Multiple Point-to-Point Tracking Application

A technique is presented to design input signals for point-to-point control problems with the property of minimal excitation of parasitic system oscillations. This technique is compared to impulse based input design techniques in experiments performed on an industrial XY-positioning table. Impulse input shaping was formulated as a solution to an optimisation problem, which has been transformed for the case of point-to-point problems, resulting in a more time-optimal solution. The results from this new optimisation are very impressive considering the simplicity.

Input design for optimal discrete time point-to-point motion of an industrial XY-positioning table

Comparison of Standard and Lifted ILC on a Motion System

Iterative Learning Control (ILC) is a technique for improving the performance of systems or processes that operate repetitively over a x ed time interval. The basic idea of ILC is that it exploits every possibility to incorporate past repetitive control information, such as tracking errors and control input signals into the construction of the present control action. Past control information is stored and then used in the control action in order to ensure that the system meets the control specications such as convergence. The goal of the research presented in this paper is to liken two different ILC techniques applied to the wafer stage of a wafer scanner motion system. Namely, we consider briey the concepts of standard and lifted ILC and we evaluate the ILC performance in terms of tracking errors.

/pdf/standard-and-lifted-approaches-of-iterative-and-learning-39u983pp06.pdf

Branko Dijkstra

Papers

Input design for optimal discrete time point-to-point motion of an industrial XY-positioning table

Comparison of Standard and Lifted ILC on a Motion System

Standard and lifted approaches of iterative and learning control applied on a motion system