Position controller

A position controller that performs position control by outputting a drive signal to a control valve of a hydraulic actuator that changes an operation position of an object, the position control comprising:

• a position acquisition unit that acquires an actual value of an operation position of the object;
• a position control unit that calculates an operation command value for the control valve by closed-loop control so as to reduce a deviation between a target value of the operation position of the object and the actual value;
• a vibration wave application unit that applies a vibration wave to a signal of the closed-loop control so that the operation command value vibrates at a predetermined frequency at start of the closed-loop control;
• and
• an oil temperature acquisition unit that acquires information on an oil temperature of the hydraulic actuator,
• wherein, when it is determined that the oil temperature acquired by the oil temperature acquisition unit is lower than a reference temperature at the start of the closed-loop control, the vibration wave application unit applies the vibration wave to the signal of the closed-loop control.

A position controller that performs position control by outputting a drive signal to a control valve of a hydraulic actuator that changes an operation position of an object, the position control comprising:

• a position acquisition unit that acquires an actual value of an operation position of the object;
• a position control unit that calculates an operation command value for the control valve by closed-loop control so as to reduce a deviation between a target value of the operation position of the object and the actual value;
• a vibration wave application unit that applies a vibration wave to a signal of the closed-loop control so that the operation command value vibrates at a predetermined frequency at start of the closed-loop control;
• and
• a warm-up acceleration unit that outputs a drive signal to the control valve so as to reciprocate a spool of the control valve during a warm-up operation before the start of the closed-loop control,
• wherein a frequency of the vibration wave of the vibration wave application unit is higher than a frequency of the drive signal of the warm-up acceleration unit.