Control system, control method, and program

A control method for performing control about a motion path of a control target along which the control target possibly makes direct or indirect contact with an object, the control method comprising:

• a model predictive control step including determining, using model predictive control, a manipulative variable to bring external force applied from the object to the control target at a time of the contact into agreement with target force;
• a determination step including determining whether a state of the contact of the control target with the object at a first point in time is a first state or a second state, the first point in time being either simultaneous with, or later than, a second point in time when vibration is produced by the contact of the control target with the object, the first state being a state before the vibration settles, the second state being a state after the vibration has settled;
• and
• an adjustment step including adjusting, in accordance with a decision made in the determination step, a horizon length of at least one horizon selected from the group consisting of a prediction horizon and a control horizon, both the prediction horizon and the control horizon being applied to the model predictive control.