Conveyance robot system, method of controlling a conveyance robot and non-transitory computer readable storage medium storing a robot control program

A method of controlling a conveyance robot comprising:

• a robot arm to which an end effector for holding an object is attached and configured to move a position of the end effector;
• a wheel configured to move a housing;
• a safety cover configured to cover the housing and provided with an arm opening in a predetermined surface of the conveyance robot from which the robot arm is extended and in which the robot arm is retracted;
• a storage box space for placing a storage box for storing the picked up object in the safety cover;
• an intrusion detection sensor configured to detect an intrusion of an object into the arm opening;
• and
• a distance sensor configured to measure a clearance distance indicating a distance between an arm entry/exit surface and a shelf, the arm entry/exit surface being a surface of the conveyance robot in which the arm opening is provided from among surfaces of the conveyance robot constituting the safety cover, and the object being stored in the shelf, wherein the distance sensor comprises two or more distance sensors disposed separately from each other along a horizontal direction of the shelf, the method comprising:
• disposing the two or more distance sensors at a fixed height of the shelf in the horizontal direction and at a height of the shelf corresponding to a part to be measured;
• moving the housing so that each of the clearance distances obtained from the two or more distance sensors becomes a distance within a predetermined range;
• disabling the intrusion detection sensor and allowing the robot arm to perform a work by extending from the housing when the clearance distance becomes less than or equal to a high-speed work allowance threshold;
• and
• when the clearance distance is greater than the high-speed work allowance threshold, removing an operation speed limit of the robot arm only inside the safety cover.

A non-transitory computer readable storage medium storing a robot control program executed by a robot control unit in a conveyance robot system comprising:

• a conveyance robot;
• and
• the robot control unit configured to control an operation of picking up an object performed by the conveyance robot, wherein
• the conveyance robot comprises:
• a robot arm to which an end effector for holding the object is attached and configured to move a position of the end effector;
• a wheel configured to move a housing;
• a safety cover configured to cover the housing and provided with an arm opening in a predetermined surface of the conveyance robot from which the robot arm is extended and in which the robot arm is retracted;
• a storage box space for placing a storage box for storing the picked up object in the safety cover;
• an intrusion detection sensor configured to detect an intrusion of an object into the arm opening;
• and
• a distance sensor configured to measure a clearance distance indicating a distance between an arm entry/exit surface and a shelf, the arm entry/exit surface being a surface of the conveyance robot in which the arm opening is provided from among surfaces of the conveyance robot constituting the safety cover, and the object being stored in the shelf, wherein
• the distance sensor comprises two or more distance sensors disposed separately from each other along a horizontal direction of the shelf, the two or more distance sensors being disposed at a fixed height of the shelf in a horizontal direction and at a height of the shelf corresponding to a part to be measured,
• the robot control unit is configured to move the housing so that each of the clearance distances obtained from the two or more distance sensors becomes a distance within a predetermined range,
• the robot control program is configured to disable the intrusion detection sensor and to allow the robot arm to perform a work by extending from the housing when the clearance distance becomes less than or equal to a high-speed work allowance threshold, and the robot control unit is configured to, when the clearance distance is greater than the high-speed work allowance threshold, remove an operation speed limit of the robot arm only inside the safety cover.