Affiliation:
1. Korea Advanced Institute of Science and Technology Department of Mechanical Engineering Taejon, Korea
Abstract
A poppet-type electropneumatic servovalve developed in this study utilizes a poppet directly operated by a moving-coil actuator in the metering stage and is controlled by a digital controller. This servovalve is insensitive to air contamination and has no problem of air leakage at null, but it has relatively large friction between the O-rings installed in the peripheral grooves of the balance pistons and the valve sleeve. For friction compensation control, a static friction model that enables simulation of the stick-slip phenomena and a dynamic model that captures the friction behaviour such as presliding displacement and varying break-away force are presented. The parameters for the friction models are identified by utilizing an evolution strategy, one of the evolutionary algorithms, which is a probabilistic global search algorithm based on the model of natural evolution. These friction models are then used in designing a non-linear friction compensation controller. It is found in the experiment that the electropneumatic servovalve has almost no hysteresis and that the friction compensation control significantly improves valve performance. The experimental results of the open loop test on poppet positioning agree well with simulation results of the valve model with identified friction parameters. It is also shown that the experimental results of friction compensation control using a static friction model show a small steady state error but those using a dynamic friction model show almost no such error.
Subject
Mechanical Engineering,Control and Systems Engineering
Reference25 articles.
1. Further Study of a Low-Pressure on-off Pneumatic Servomechanism
2. Choi S. H., Ann C., Lee C. O. Application of fuzzy logic adaptor to the position control of a pneumatic system using on-off valves. In Proceedings of the ASME International Mechanical Engineering Congress and Exposition, FPST-Vol. 2, San Francisco, California, 1995, pp. 21–28 (American Society of Mechanical Engineers, New York).
3. Adaptive Tracking Control of an Air Powered Robot Actuator
4. The application of servo-pneumatic drives for flexible mechanical handling techniques
Cited by
4 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献