Abstract
In the field of a precise positioning, an active isolation system, which is arranged 6 acceleration sensors in total in the horizontal and vertical direction, is generally installed and measures the movement of 6 degrees-of-freedom. In this case, the body supported by isolation unit has inclination Θ of the direction of pitch or roll, inclination components are superimposed to the acceleration sensor output of horizontal direction. When this component is canceled by high pass filter, the body oscillates in the cutoff frequency of the filter. Therefore, the inclination angle Θ is measured by position sensing devices equipped with isolation unit, and the inclination component can be correctly compensated. Then, the necessary performance for isolation unit is able to be achieved.
