Work robot

A work robot designed to perform a given work while traveling autonomously over a given area, the work robot comprising:

• a traveling device configured to switch between forward and backward movements of the work robot, and change an orientation of the work robot;
• collision sensors configured to output a signal regarding a collision between the work robot and an obstacle;
• and
• a control device configured to determine, based on the signal received from the collision sensors, whether or not the work robot has collided with an obstacle, and further determine a collision side indicative of whether the work robot has collided with the obstacle on a left side with respect to a center of the work robot, or has collided with the obstacle on a right side with respect to the center of the work robot, so as to control the traveling device,
• wherein the collision sensors comprise a magnet, and a hall sensor having a detection part to detect an intensity of a magnetic field generated by the magnet, the hall sensor being configured to output a signal corresponding to the intensity of the magnetic field,
• in a direction parallel to a straight line passing through an N pole and an S pole of the magnet, the detection part of the hall sensor is disposed at a position between an N pole-side end and an S pole-side end of the magnet,
• the position of the detection part of the hall sensor with respect to the magnet is changeable in the direction parallel to the straight line, based on the collision between the work robot and the obstacle,
• the collision sensors have a first collision sensor and a second collision sensor,
• the magnet of the first collision sensor is disposed such that the straight line passing through the N pole end and the S pole thereof passes through the center of the work robot and becomes approximately parallel to a center line extending along a forward/backward direction of the work robot,
• the magnet of the second collision sensor is disposed such that the straight line passing through the N pole end and the S pole thereof becomes approximately orthogonal to the center line, and
• based on the signals received from the first and second collision sensors during the forward movement and during the backward movement, the control device is configured and/or operable to determine that the work robot has collided with the obstacle with an external force applied to the work robot in a direction inclined to the center line that indicates a collision on the left side or a collision on the right side with respect to the center of the work robot, and the control device is configured and/or operable to control the traveling device to change the orientation of the work robot toward a side opposite to the collision side, and then move the work robot forwardly.