Device for controlling return of robot to origin thereof, and method of searching return path of robot to origin thereof

A non-transitory computer-readable storage medium storing a program therein, the program enabling a CPU (central processing unit) serving as a calculator to access a recording unit in which operation log data of a robot with a movable arm is recorded, to perform steps for searching a return path along which a position and a posture of the arm of the robot is returned from the current position to an origin previously set on a trajectory of the robot, based on the operation log data,

• the program enables the CPU to functionally perform,
• return necessity determining step determining whether it is necessary to return the arm from the current position to the origin;
• straight-line portion determining step determining whether there is a trajectory portion regarded as being a straight line on a motion trajectory of the arm, based on the operation log data recorded in the recording unit at a time when the return necessity determining step determines that the arm is necessary to be returned to the origin, the motion trajectory being provided at or before the return necessity determination;
• decimating step decimate operation log data of a node which are present between two nodes which are at both ends of the trajectory portion regarded as being a straight line in a time-series space produced at every constant timing, when the straight-line portion determining step determines that there is the trajectory portion regarded as being the straight line on the motion trajectory of the arm;
• and
• calculating step calculating the return path along which the arm returns to the origin, based on remaining operation log data which are left in the operation data log after the decimation.

A device for controlling return of a robot with a movable arm, by which the arm is returned to a previously set origin in a space in which the arm is allowed to move, comprising:

• a recording unit into which a position and a posture of the arm are recorded at constant timing as operation log data of the robot;
• and
• a controller controlling motions of the arm,
• wherein the controller comprises:
• a return necessity determining unit determining whether it is necessary to return the arm from the current position to the origin;
• a straight-line portion determining unit determining whether there is a trajectory portion regarded as being a straight line on a motion trajectory of the arm, based on the operation log data recorded in the recording unit at a time when the return necessity determining unit determines that the arm is necessary to be returned to the origin, the motion trajectory being provided at or before the return necessity determination;
• a decimating unit decimate operation log data of a node which are present between two nodes which are at both ends of the trajectory portion regarded as being a straight line in a time-series space produced at every constant timing, when the straight-line portion determining unit determines that there is the trajectory portion regarded as being the straight line on the motion trajectory of the arm;
• and
• a calculating unit calculating the return path along which the arm returns to the origin, based on remaining operation log data which are left in the operation data log after the decimation.