Aparatus for controlling the displacement of an object between any two points

Claim 1

Apparatus for controlling the displacement of an object between any two points wherein a direct current motor is provided comprising: a first generator means for generating a first signal representative of the distance remaining to be traveled by said object, said first generator means comprising: means for receiving a signal representative of the distance which said object must travel between said two points, means for measuring the current position of said object and for providing a signal representative of the current position, a distance reducer means for reducing the signal representative of the distance which said object must travel by the amount of distance traveled by said object, said distance reducer means comprising a digital register followed by a digital to analog converter; a second generator means for generating a second signal representative of the actual speed of said object; a function generator, controlled by the first signal representative of the distance remaining to be traveled by said object, for generating a reference speed signal; means for comparing the second signal representative of the actual speed of said object with the reference signal and for generating an error signal indicative of the signal difference; and control means for controlling the polarity of the supply voltage to said direct current motor in accordance with the polarity of said error signal.