Robot system, parallel link mechanism, control method, control device, and storage medium

A control method of a robot system,

• the robot system including:
• an arm mechanism that is articulated;
• a parallel link mechanism having at least four degrees of freedom with respect to the arm mechanism, the parallel link mechanism including
• a fixed part mounted to a distal part of the arm mechanism, and
• a movable part mounted to the fixed part via a plurality of parallel links,
• the movable part being movable with respect to the fixed part;
• an end effector mounted to the movable part, the end effector including a plurality of ultrasonic sensors;
• and
• a detector configured to detect a position or orientation of a control point, the control point being set at a part of the movable part or a part of the end effector,
• the method comprising:
• a first step of setting a posture of the control point to a first posture by moving the arm mechanism, the first posture being prescribed;
• a second step of setting the posture of the control point to a task posture by moving the parallel link mechanism based on a detection result of the detector, the second step being performed after the first step, the end effector performing a task in the task posture;
• referring to a reception result of a reflected wave after the second step, the plurality of ultrasonic sensors transmitting an ultrasonic wave to a task object to obtain the reception result;
• calculating an angle between the plurality of ultrasonic sensors and a direction perpendicular to the task object based on the reception result;
• and
• moving the parallel link mechanism so that the angle becomes smaller.

A control device controlling a robot system,

• the robot system including:
• an arm mechanism that is articulated;
• a parallel link mechanism having at least four degrees of freedom with respect to the arm mechanism, the parallel link mechanism including
• a fixed part mounted to a distal part of the arm mechanism, and
• a movable part mounted to the fixed part via a plurality of parallel links,
• the movable part being movable with respect to the fixed part;
• an end effector mounted to the movable part, the end effector including a plurality of ultrasonic sensors;
• and
• a detector configured to detect a position or orientation of a control point, the control point being set at a part of the movable part or a part of the end effector,
• the control device performing:
• a first operation of setting a posture of the control point to a first posture by moving the arm mechanism, the first posture being prescribed;
• a second operation of setting the posture of the control point to a task posture by moving the parallel link mechanism based on a detection result of the detector, the second operation being after the first operation, the end effector performing a task in the task posture;
• referring to a reception result of a reflected wave after the second operation, the plurality of ultrasonic sensors transmitting an ultrasonic wave to a task object to obtain the reception result;
• calculating an angle between the plurality of ultrasonic sensors and a direction perpendicular to the task object based on the reception result;
• and
• moving the parallel link mechanism so that the angle becomes smaller.

A non-transitory computer-readable storage medium storing a program,

• the program causing a control device to perform a first operation and a second operation,
• the control device controlling a robot system,
• the robot system including:
• an arm mechanism that is articulated;
• a parallel link mechanism having at least four degrees of freedom with respect to the arm mechanism, the parallel link mechanism including
• a fixed part mounted to a distal part of the arm mechanism, and
• a movable part mounted to the fixed part via a plurality of parallel links, the movable part being movable with respect to the fixed part;
• an end effector mounted to the movable part, the end effector including a plurality of ultrasonic sensors;
• and
• a detector configured to detect a position or orientation of a control point, the control point being set at a part of the movable part or a part of the end effector,
• the first operation setting a posture of the control point to a first posture by moving the arm mechanism, the first posture being prescribed,
• the second operation setting the posture of the control point to a task posture by moving the parallel link mechanism based on a detection result of the detector, the second operation being after the first operation, the end effector performing a task in the task posture,
• after the second operation, the program further causing the control device to
• refer to a reception result of a reflected wave, the plurality of ultrasonic sensors transmitting an ultrasonic wave to a task object to obtain the reception result,
• calculate an angle between the plurality of ultrasonic sensors and a direction perpendicular to the task object based on the reception result, and
• move the parallel link mechanism so that the angle becomes smaller.