Motor control apparatus, motor control method, control system, and position estimation method to be used in control system

A control system for use with a body to be controlled, the control system comprising:

• a motor structured to drive said body to be controlled;
• a sensor structured to detect position data of said body to be controlled, based on the rotational angle of said motor, at a predetermined cycle;
• a servo control unit structured to servo-control said motor;
• and
• a position control unit configured to issue an operation command (a position command) to said servo control unit;
• wherein said position control unit comprises a command generating means for generating an operation command to said servo control unit, a position data storage means for storing said position data obtained from said sensor together with the obtaining time, and a position estimating means for estimating the position of said body to be controlled at a time, based on said position data taken at a predetermined cycle;
• said position estimating means is configured to express the position f(t) of said body to be controlled at time t by a polynomial based on said position data to estimate the position of said body to be controlled at said time through a polynomial interpolation;
• wherein said position estimating means is configured to estimate the position of said body to be controlled at said time using a third-order polynomial;
• and
• wherein said position estimating means is configured to, based on position data at said time at which the position of said body to be controlled is estimated, estimate the position of said body to be controlled at said time.