To obtain a compensation apparatus which can compensate an influence on the response waveform of a vibration base with reference to a load change and to a disturbance applied to the vibration base by a method wherein disturbance- estimation compensator which generates an input used to compensate and offset the disturbance applied to the vibration base by means of the feedback of a displacement is installed at a feedback circuit.
When a desired value is applied as a voltage from a vibration signal device 11, the voltage is converted into a current so as to be amplified by a servoamplifier 12 which is composed of adders 7, 8 and of an amplifier 6, and the current is supplied to a servo valve 3. The acceleration of a table detected by an acceleration detector 5 and a speed which is converted by integrating an acceleration by using a feedback control device 9 which is composed of an integrator 12, of a accelerometer 14 and of a displacement meter 15 are fed back to the adders as voltage signals. When a disturbance is applied to the table, an acceleration signal is sent to a disturbance observer 10, the disturbance observer 10 compares the acceleration signal with a deviation due to the vibration signal device and due to a feedback signal, and a signal which offsets the disturbance is superposed on the adder 8.
FUJIWARA KOJI
HIRAI HIROTAKE
KOBAYASHI MASATO
