Servo control system carrying out coarse control and fine control

A servo control system, comprising:

• a controlled system including a controlled object to be position controlled and a drive unit for driving said controlled object;
• speed control means for controlling the speed of said controlled object through said drive unit to move and position said controlled object to a reference position;
• differential means for differentiating a position signal for indicating a position of said controlled object and outputting a differential signal;
• integral means for integrating said position signal and outputting an integration signal;
• adding means for adding said differential signal from said differential means, said integration signal from said integral means, and said position signal;
• and
• control means for controlling the position of said controlled object to move to said reference position, said controlling of said control means being carried out after said controlled object is moved to the position adjacent to said reference position by said speed control means.

A servo control system, comprising:

• speed error generation means for generating a speed error signal based on a position signal from a controlled object;
• position error generation means for receiving and adding a differential signal of said position signal, an integration signal of said position signal, and said position signal to generate a position error signal;
• control means for switching from a coarse control mode for driving said controlled object by said speed error signal to a fine control mode for driving said controlled object by said position error signal;
• and
• differential means for obtaining said differential signal of said position error generation means having a variable gain, the gain of said differential means being increased for a predetermined period of time from a point at which said control means switches from said coarse control mode to said fine control mode.