A desired position instruction of a user is generated even if a plurality of position instructions satisfying a vibration control condition exist. An instruction generator includes a conditional expression selector configured to select a conditional expression that should generate the position instruction from a plurality of conditional expressions based on a control performance condition, a parameter calculator configured to calculate a parameter based on a machine performance index and the selected vibration control conditional expression, and a position instruction generator configured to calculate the position instruction based on the parameter.

A desired position instruction of a user is generated even if a plurality of position instructions satisfying a vibration control condition exist. An instruction generator includes a conditional expression selector configured to select a conditional expression that should generate the position instruction from a plurality of conditional expressions based on a control performance condition, a parameter calculator configured to calculate a parameter based on a machine performance index and the selected vibration control conditional expression, and a position instruction generator configured to calculate the position instruction based on the parameter.