Methods of calibrating positions of wheels in an automated guided vehicle, and automated guided vehicle

An automated guided vehicle, AGV, comprising a support structure and at least two drive units connected to the support structure, wherein each drive unit comprises:

• a wheel rotatable about a wheel axis and about a steering axis perpendicular to the wheel axis;
• a wheel motor arranged to drive the wheel about the wheel axis;
• a wheel sensor device arranged to determine a rotational position of the wheel about the wheel axis;
• a steering motor arranged to drive the wheel about the steering axis;
• and
• a steering sensor device arranged to determine a rotational position of the wheel about the steering axis;
• wherein a controller is configured to calibrate positions of the wheels of the at least two drive units,
• wherein for calibrating the positions of the wheels, the controller is configured to:
• position a second wheel tangentially on an imaginary second circle centered with respect to a center position in which a first wheel is fixed;
• drive the second wheel a second distance along the second circle such that the AGV rotates about the center position;
• determine the second distance based on data from the second wheel sensor device of the second wheel;
• determine an angle of rotation about the center position based on data from the first steering sensor device of the first wheel during the rotation of the AGV;
• and
• determine relative positions between the first wheel and the second wheel based on the second distance and the angle of rotation.