Digital system for controlling the wheels of a heavy-duty commercial vehicle

Steering system for a vehicle having a plurality of individually controllable wheels, comprising, in combination, first means for furnishing a desired angular position signal varying as a linear function of the desired angular position of said wheels relative to a determined axis of said vehicle;

• second means for furnishing actual position signals varying as a linear function of the actual position of said wheel relative to said determined axis, at least said first or said second means comprising means for furnishing a digital signal having a plurality of determined values each corresponding to one of a plurality of angular positions of said wheels relative to said determined axis;
• and control means connected to said first and second means and said wheels for adjusting the angular position of said wheels as a function of said desired and actual position signals, said control means comprising computer means for computing a non-linear position signal varying as a predetermined non-linear function of said desired or said actual position signals, comparator means for comparing said non-linear position signal to the other of said desired and actual position signals and furnishing a difference signal corresponding to the difference therebetween, and output means connected to said comparator means for controlling said angular position of said wheels in such a manner that the amplitude of said difference signal decreases towards zero.

Steering system for a vehicle having a plurality of individually controllable wheels, comprising, in combination, first means for furnishing a desired angular position signal indicative of the desired angular position of said wheels relative to a determined axis of said vehicle;

• second means for furnishing actual position signals indicative of the actual position of said wheel relative to said determied axis, at least said first or said second means comprising means for furnishing a digital signal having a plurality of determined values each corresponding to one of a plurality of angular positions of said wheels relative to said determined axis, at least said first or said second means having a non-linear transfer characteristic whereby said desired or said actual position signal varies as a predetermined non-linear function of said desired or actual position of said wheels respectively;
• and control means connected to said first and second means and said wheels for adjusting the angular position of said wheels as a function of said desired and actual position signals, said control means comprising comparator means for directly comparing the so-furnished actual and desired position signals and furnishing a difference signal corresponding to the difference therebetween, and output means connected to said comparator means for controlling said angular position of said wheels in such a manner that the amplitude of said difference signal decreases towards zero.