Patent ID: 7278511

Claim:
A vehicle for traveling along the ground, the vehicle comprising: at least one rear wheel; at least one front wheel; an actuator coupled to the at least one rear wheel for rotating the at least one rear wheel about a steering axis; an input device operable to select one of a plurality of steering modes, the input device providing an input signal corresponding to the selected one of the plurality of steering modes; a means for providing an enabling signal for enabling the selected one of the plurality of steering modes, the means for providing an enabling signal including at least one sensor and a comparator, the comparator operably coupled to the at least one sensor for detecting a degree of slippage between either one of the front and rear wheels and the ground, the comparator comparing the degree of slippage to a threshold and generating the enabling signal when the degree of slippage is greater than the threshold; and a controller responsive to the input signal and the enabling signal for controlling the actuator to rotate the at least one rear wheel in accordance with the selected one of the plurality of steering modes.