Abstract: It is constructed so as to be able to follow without delay and flexibly cope with a change in a command of a host controller in the case of receiving a target command value at the present time from the host controller every certain period. In a servo control apparatus 2 for causing an output of a controlled object 3 to follow target commands received from a host controller 1 every certain period, predictive target commands to the next M steps are generated every each period using a history of the target commands and command follow-up control is performed by predictive and preview control or feedback gain switching control using the predictive target commands.

Abstract: Flexible structures with two or more inertia systems connected through spring elements have heretofore presented problems that references and loads do not perfectly accord and that complicated calculations required involve an enormous amount of calculations, a servo control method using feed-forward is characterized by comprising the steps of expressing the position of a load and the position of a motor in respective functions capable of higher order differentiation, determining such functions capable of higher order differentiation from operating conditions (4) and mechanical parameters (5), calculating the motor position, speed and torque reference from the determined functions capable of higher-order differentiation, and using the calculated motor position, speed and torque reference as feed-forward references or of calculating a motor torque reference from the determined function capable of higher order differentiation, inputting the calculated torque reference into a mechanical model, and using the obtai