Control system for power unit

A control system for a power unit that has an actuator, which outputs a driving force for actuating an element to be driven, and a spring member, which receives the driving force of the actuator through the intermediary of a power transmission element, converts the received driving force into an elastic force, and outputs the elastic force to the element to be driven, the power transmission element being configured to have springiness between an input section thereof adjacent to the actuator and an output section thereof adjacent to the spring member, the control system comprising:

• a force detecting unit that generates an output based on a force actually applied to the element to be driven;
• a displacement motion detecting unit that generates an output based on a displacement motion of an output section of the actuator;
• a basic command value determining unit that sequentially determines a basic command value for controlling the driving force of the actuator according to an output of the force detecting unit and a desired value of a force to be applied to the element to be driven so as to converge a value of a force indicated by an output of the force detecting unit to the desired value of the force;
• an actuator control unit that sequentially determines a desired actuator control value that defines a driving force to be actually output from the actuator and controls the actuator according to the desired actuator control value;
• and
• a manipulated variable determining unit that determines a manipulated variable for correcting the basic command value based on an output of the displacement motion detecting unit, an output of the force detecting unit, and a desired actuator control value determined by the actuator control unit so as to bring a driving force, which is to be applied to the element to be driven according to the desired actuator control value, close to a resultant force of an inertial force, which is defined by a value of a displacement acceleration of the output section of the actuator indicated by an output of the displacement motion detecting unit and a set value of an inertial mass or an inertial moment of a system extending from the actuator to the spring member, and a force indicated by an output of the force detecting unit,
• wherein the actuator control unit is configured to determine the desired actuator control value by correcting the basic command value according to the manipulated variable at the time of determining a new desired actuator control value.