A robotic lawnmower comprises, inter alia, a chassis (2), a body which is movably fitted to the chassis by means of at least one suspension (7, 8) and at least one collision sensor for detecting an obstacle by sensing a movement of the body relative to the chassis when the lawnmower collides with the obstacle, and for providing sensor signals indicative thereof for bringing the lawnmower to respond, e.g. stop or change traversing direction. The suspension (7, 8) comprises a joystick element (12) by means of which the body is fitted to the chassis (2) and a resilient positioning member (13) for holding the joystick element in a neutral position (N). The resilient positioning member (13) also permits movement of the joystick element (12) when the lawnmower collides with the obstacle and the body moves relative to the chassis (2), and return of the joystick element to the neutral position (N) after the collision. The resilient positioning member (13) of the suspension (7, 8) is a spring element (14) of a time and wear resistant material.
