Force control device, force control method, and force control program

A force control method performed by a computer, the method comprising:

• a position detecting step of detecting a position of a control target;
• a force detecting step of detecting a force by which the control target is in contact with an object;
• a computing step of computing a torque command value for a driving unit that includes a motor that uses the torque command value as an input to operate a moving mechanism that movably holds the control target;
• and
• a moving step of moving the control target based on a computation result of the computing step, wherein the computing step comprises:
• calculating a position at a next time, the position being calculated by simulating a motion of a virtual object when a target force exerted on the control target and a measured value of the force detecting step are given to the virtual object, using the virtual object and a position control rule that are stored in the computer, the virtual object having predetermined dynamic characteristics;
• obtaining a torque calculated when the calculated position is given to the position control rule as a target position at the next time;
• when the obtained torque is within a predetermined range set previously, determining the obtained torque as the torque command value to determine the calculated position as a position of the virtual object at the next time;
• and
• when the obtained torque is outside the predetermined range set previously, determining the position of the virtual object at the next time based on a boundary value of the predetermined range and the obtained torque.

A force control program that makes a computer to function as:

• position detecting means for detecting a position of a control target;
• force detecting means for detecting a force by which the control target is in contact with an object;
• computing means for computing a torque command value for a driving unit that includes a motor that uses the torque command value as an input to operate a moving mechanism that movably holds the control target;
• and
• moving control means for controlling a movement of the control target based on a computation result of the computing means, wherein the computing means:
• calculates a position at a next time, the position being calculated by simulating a motion of the virtual object when a target force exerted on the control target and a measured value detected by the force detecting means are given to the virtual object, using the virtual object and a position control rule that are stored in the computer, the virtual object having predetermined dynamic characteristics;
• obtains a torque calculated when the calculated position is given to the position control rule as a target position at the next time;
• when the obtained torque is within a predetermined range set previously, determines the obtained torque as the torque command value to determine the calculated position as a position of the virtual object at the next time;
• and
• when the obtained torque is outside the predetermined range set previously, determines the position of the virtual object at the next time based on a boundary value of the predetermined range and the obtained torque.