Control device, control program and control method

A control program stored in a non-transitory storage that controls a control system which contains a motion body and a driving source driving the motion body, enabling a computer to execute the steps as follows:

• obtaining a torque actual value and a velocity actual value, wherein the torque actual value represents a torque generated by the driving source for driving the motion body and the velocity actual value represents a velocity of the motion body;
• calculating an external force inferred value and a velocity inferred value every other operation period based on the torque actual value by using an operation formula of a predetermined model representing driving of the motion body, wherein the external force inferred value represents an external force generated by the control system, the velocity inferred value corresponds to the external force inferred value and represents a velocity of the motion body, and the operation formula contains items for updating the velocity inferred value and the external force inferred value such that the velocity actual value and the velocity inferred value are consistent;
• evaluating a reliability of the external force inferred value based on the velocity inferred value calculated together if the external force inferred value is calculated, and effectively outputting the external force inferred value when it is judged that there is a designated reliability;
• and
• maintaining an output value of the external force inferred value output at the previous time when judging there is no designated reliability, where the designated reliability is dynamically decided by a setting of a disturbance observer,
• wherein the step of evaluating the reliability of the external force inferred value based on the velocity inferred value calculated together if the external force inferred value is calculated comprises:
• judging that there is the designated reliability when a difference between the velocity inferred value and the corresponding velocity actual value is smaller than a predetermined value.

A control method that controls a control system which contains a motion body and a driving source driving the motion body, comprising the steps as follows:

• obtaining a torque actual value and a velocity actual value, wherein the torque actual value represents a torque generated by the driving source for driving the motion body and the velocity actual value represents a velocity of the motion body;
• calculating an external force inferred value and a velocity inferred value every other operation period based on the torque actual value by using an operation formula of a predetermined model representing driving of the motion body, wherein the external force inferred value represents an external force generated by the control system, the velocity inferred value corresponds to the external force inferred value and represents a velocity of the motion body, and the operation formula contains items for updating the velocity inferred value and the external force inferred value such that the velocity actual value and the velocity inferred value are consistent;
• evaluating a reliability of the external force inferred value based on the velocity inferred value calculated together if the external force inferred value is calculated, and effectively outputting the external force inferred value when it is judged that there is a designated reliability;
• and
• maintaining an output value of the external force inferred value output at the previous time when judging there is no designated reliability, where the designated reliability is dynamically decided by a setting of a disturbance observer,
• wherein the step of evaluating the reliability of the external force inferred value based on the velocity inferred value calculated together if the external force inferred value is calculated comprises:
• judging that there is the designated reliability when a difference between the velocity inferred value and the corresponding velocity actual value is smaller than a predetermined value.