Angle calibration method

An angle calibration method for calibrating an angle of a robot, the robot including

• a first member,
• a second member that is coupled to the first member in a relatively rotatable manner, and
• an actuator that changes an angle of the second member relative to the first member in accordance with a command value,
• the angle calibration method comprising:
• a first step of obtaining a measurement object distance, which is a distance between two measurement object portions including a first measurement object portion in the first member and a second measurement object portion in the second member, by measuring a distance between wall surfaces of the two measurement object portions, the measurement being made while the actuator is given an arbitrary command value;
• and
• a second step of obtaining an angular difference by calculation, the angular difference corresponding to a difference in distance between two measurement object portions, the calculation being made based on a reference measurement object distance obtained in the past and the measurement object distance obtained in the first step, the reference measurement object distance having been obtained by measuring the measurement object distance while the actuator was given an arbitrary command value, wherein
• one of the two measurement object portions is a pin that protrudes from the first member, and
• the other of the two measurement object portions is a pin that protrudes from the second member,
• at least one of the two pins is removable from the first member or the second member,
• at least one of the two pins has a tapered portion, and
• the first member or the second member has a tapered recess corresponding to the tapered portion.

An angle calibration method for calibrating an angle of a robot, the robot including

• a first member,
• a second member that is coupled to the first member in a relatively rotatable manner, and
• an actuator that changes an angle of the second member relative to the first member in accordance with a command value,
• the angle calibration method comprising:
• a first step of obtaining a measurement object distance, which is a distance between two measurement object portions including a first measurement object portion in the first member and a second measurement object portion in the second member, by measuring a distance between wall surfaces of the two measurement object portions, the measurement being made while the actuator is given an arbitrary command value;
• and
• a second step of obtaining an angular difference by calculation, the angular difference corresponding to a difference in distance between two measurement object portions, the calculation being made based on a reference measurement object distance obtained in the past and the measurement object distance obtained in the first step, the reference measurement object distance having been obtained by measuring the measurement object distance while the actuator was given an arbitrary command value, wherein
• each of the two measurement object portions is cut in a plane perpendicular to the central axis of the second member, and a resulting cross-section has a circular contour.