Servo motor controller

A servo motor controller that controls a servo motor to drive a driving target and executes position control for controlling the position of the driving target and force control for controlling force to be applied to a subject by the driving target, the servo motor controller comprising:

• a position command generation unit that generates a position command for instructing the position of the driving target;
• a position detection unit that detects the position of the driving target;
• a position control unit that generates a velocity command for the servo motor for the position control based on the position command generated by the position command generation unit and the position detected by the position detection unit;
• a force command generation unit that generates a force command for instructing force to be applied to the subject by the driving target;
• a force detection unit that detects force applied to the subject by the driving target;
• a force control unit that generates a velocity command for the servo motor for the force control based on the force command generated by the force command generation unit and the force detected by the force detection unit;
• a selection unit that selects one of the position control and the force control;
• and
• a storage unit that stores a force threshold for selection by the selection unit, wherein
• the selection unit compares the velocity command for the position control generated by the position control unit and the velocity command for the force control generated by the force control unit, and selects one of the velocity commands of a smaller value, and
• if the force detected by the force detection unit is smaller than the force threshold, the selection unit selects the velocity command for the position control independently of a result of the comparison.