Robot system and incline detection method

A robot system comprising:

• a robotic hand configured to load and unload a workpiece into and from a cassette in which a plurality of workpieces are accommodated in multiple stages and aligned in a first direction;
• a sensor configured to detect the workpiece;
• means for changing a relative position of the sensor with respect to the cassette from a first position to a second position by changing the relative position of the sensor in a second direction intersecting the first direction,
• means for changing the relative position of the sensor in the first direction when the sensor is located at the first position so that the sensor acquires first mapping data indicating placement of the workpieces in the first direction, and changing the relative position of the sensor in the first direction when the sensor is located at the second position so that the sensor acquires second mapping data indicating the placement of the workpieces in the first direction;
• and
• means for determining a state of incline of one or more of the workpieces based on the first mapping data and the second mapping data.

A method comprising:

• arranging a sensor at a first position with respect to a cassette including multiple storage locations in which a plurality of workpieces are aligned in a first direction;
• commanding the sensor to scan in the first direction, while changing a relative position of the sensor with respect to the cassette, with the sensor arranged at the first position;
• acquiring first mapping data with the sensor arranged at the first position, the first mapping data indicating placement of the workpieces in the first direction;
• arranging the sensor at a second position different from the first position by changing the relative position of the sensor in a second direction intersecting the first direction;
• commanding the sensor to scan in the first direction, while changing the relative position of the sensor in the first direction, with the sensor arranged at the second position;
• acquiring second mapping data with the sensor arranged at the second position, the second mapping data indicating the placement of the workpieces in the first direction;
• determining that one or more of the workpieces are inclined based on the first mapping data and the second mapping data;
• and
• prohibiting entry of a robotic hand into at least one of the storage locations in response to determining that one or more of the workpieces are inclined.