Ground vehicle bumper system

A vehicle comprising:

• a body having a first outer periphery in a first plane that is parallel to a surface on which the vehicle moves in a horizontal direction;
• a bumper assembly having a second outer periphery in a second plane parallel to the first plane, the second outer periphery including portions that extend beyond the first outer periphery in the horizontal direction;
• one or more flexible couplings coupling the bumper assembly to the body, the one or more flexible couplings allowing for horizontal planar deflection of the bumper assembly relative to the body when the bumper assembly impacts an obstacle when the vehicle is moving in the horizontal direction, each of the one or more flexible couplings comprising an extension spring, an axis in which the extension spring compresses extending in a direction orthogonal to the horizontal direction when the extension spring is in a neutral position, with a first end of the extension spring being coupled to the bumper assembly and a second end of the extension spring being coupled to the body, wherein, when the bumper assembly is in horizontal planar deflection, the extension spring provides restorative force in the horizontal direction;
• one or more sensors mounted relative to the bumper assembly and to the body to detect horizontal planar deflection of the bumper assembly, the one or more sensors being configured to generate signals indicating the bumper assembly has deflected in the horizontal planar direction at least a threshold amount;
• and
• a drive system configured to propel the vehicle in the horizontal direction and that receives, as input, the signals generated by the one or more sensors and in response to the signals indicating the bumper assembly has deflected in the horizontal planar direction at least a threshold amount, causes the vehicle to stop moving in the horizontal planar direction.