An Estimation Method of Inner Pressure of Pneumatc Active Anti Vibration Apparatus Using Minimum Order Observer

Abstract

In the field of precision positioning and measurement, air-type anti-vibration apparatus are widely used. This apparatus equips an air spring which has anti-resonance and resonance characteristic on frequency response. Due to this characteristic, it is known that deformation of main body occurs for the difference of pressure each air spring. In order to avoid the deformation of main body supported by air springs and to manage the driving force, the pressure feedback was especially implemented as a minor loop. However, it is undesirable to install pressure sensors in the field of industrial application because it takes cost and the sensors have low resolution against a request for the management of the driving force. Then, this paper proposes minimum order observer to estimate inner pressure of an air spring without a pressure sensor. Some correction gains for observer are usually set by pole assignment method, however these gains are depend on parameters of plant. Therefore, observer needs adjustment of correct gains for implement. Then, this presentation proposes the minimum observer which is able to adjust with monitoring the measured frequency response, and clear the role of correction gains.