| 摘要 |
PURPOSE:To eliminate the non-linearity in the sensitivity of a detector for angle of inclination and to expand the measurement range of said detector by combining the detector for angle of inclination and a tilting device and driving the tilting device so that the signal detected by the detector for angle of inclination is made zero. CONSTITUTION:When a surface 9 to be measured inclines, a support member 8 inclines as well and a tilting table 7 which is hydrostatically supported with the member 8 inclines. The inclination of the table 7 is detected by a detector 1 for angle of inclination and is outputted to a controller 2. The controller 2 increases or decreases a control signal Vc according to the output of the detector 1. The signal Vc is outputted at all times so that the output of the detector 1 is made zero. On the other hand, the difference between the displacement detection signals of displacement detectors 18, 19 held by the member 8 is determined by a differential amplifier 20, by which the angle of inclination of the table 7 is determined and the difference thereof from the control signal Vc of the controller 2 is detected and amplified with a differential amplifier 3. The amplified error signal is servo-amplified as it passes through a compensation circuit 4 and is supplied to a servocontrol valve 6 as a control signal I. |
