Electric apparatus and control method therefor

An electric apparatus for controlling movement of a target object, comprising:

• a detector configured to detect the movement of the target object;
• a first estimation unit configured to estimate, based on a detection signal output from the detector, a control quantity for performing first feedback control for the target object during a first period;
• a second estimation unit configured to estimate, based on the detection signal output from the detector, a velocity of the target object and an acceleration obtained by time differentiation of the velocity in order to perform second feedback control for the target object during a second period shorter than the first period;
• a first generation unit configured to generate a first operation quantity for the first feedback control based on the control quantity estimated by the first estimation unit;
• a second generation unit configured to generate a second operation quantity for the second feedback control based on the velocity and the acceleration estimated by the second estimation unit;
• and
• a synthesizing unit configured to generate an operation quantity on the target object,
• wherein if one of a predetermined target value and the velocity of the target object estimated by the second estimation unit is higher than a first threshold value for the velocity, the synthesizing unit generates the operation quantity on the target object based on the first operation quantity and the second operation quantity, and if one of the target value and the velocity of the target object is lower than the first threshold value, the synthesizing unit generates the operation quantity on the target object using only the first operation quantity from among the first operation quantity and the second operation quantity,
• the first generation unit is implemented by executing a program by a processor, and
• the first estimation unit, the second estimation unit, the second generation unit, and the synthesizing unit are implemented by an ASIC.