Robot apparatus and control method

A control method of a door opening/closing robot, the control method comprising:

• providing the door opening/closing robot including:
• a base provided at a position different from a conveyance line on which a vehicle body is conveyed,
• a first arm attached to the base to rotate around a first axis extending along a vertical direction, and extending away from the first axis,
• a second arm attached to the first arm to rotate around a second axis parallel to the first axis, and extending away from the second axis,
• a third arm attached to the second arm to rotate around a third axis parallel to the first axis, and extending in a direction intersecting the third axis and away from the third axis, and
• a fourth arm provided with a tool capable of holding a door attached to the vehicle body, and attached to the third arm to extend along the vertical direction and rotate around a fourth axis parallel to the first axis,
• controlling the door opening/closing robot such that the tool of the fourth arm opens the door at an upstream side of the first axis in a direction of the conveyance line;
• controlling the door opening/closing robot such that an opened state of the door is maintained while the vehicle body is being conveyed along the conveyance line;
• and
• controlling the door opening/closing robot such that the tool of the fourth arm closes the door at a downstream side of the first axis in the direction of the conveyance line.

A robot apparatus comprising:

• a door opening/closing robot configured to perform a predetermined work;
• and
• a controller configured to control the door opening/closing robot,
• wherein the door opening/closing robot includes:
• a base provided at a position different from a conveyance line on which a vehicle body is conveyed,
• a first arm attached to the base to rotate around a first axis extending along a vertical direction, and extending away from the first axis;
• a second arm attached to the first arm to rotate around a second axis parallel to the first axis, and extending away from the second axis,
• a third arm attached to the second arm to rotate around a third axis parallel to the first axis, and extending away from the third axis, and
• a fourth arm provided with a tool capable of holding a door attached to the vehicle body, and attached to the third arm to extend along the vertical direction,
• wherein the door opening/closing robot is disposed between a side surface of the vehicle body that is being conveyed along the conveyance line and a booth side wall formed along the conveyance line, and
• wherein the controller is configured to sequentially perform:
• a door opening control for controlling the door opening/closing robot such that the tool opens the door at an upstream side of the first axis in a direction of the conveyance line,
• a door following control for controlling the door opening/closing robot such that an opened state of the door is maintained while the vehicle body is being conveyed along the conveyance line, and
• a door closing control for controlling the door opening/closing robot such that the tool closes the door at a downstream side of the first axis in the direction of the conveyance line,
• wherein, in the door following control, the controller controls the door opening/closing robot such that a portion where the tool holds the door moves on a holding line which is in parallel with the conveyance line, and
• wherein the fourth arm is attached to the third arm to rotate together with the tool around a fourth axis parallel to the first axis, and
• in the door following control, the controller controls the door opening/closing robot such that when viewed in a vertical direction, a virtual line segment connecting the portion where the tool holds the door and the fourth axis maintains a predetermined angle with respect to the door.