Steering method and system employing ellipsoidal relationships

Claim 3

The method of claim 1 wherein the modifying of step (d) comprises interrupting the steer signal to the oversteered wheel that is being steered more than its said relative degrees of steer with respect to said other steerable wheel.

Claim 4

The method of claim 2 wherein two outside nonsteering wheels are also attached to said frame and said identical ellipses have a distance between the two focal points on each respective major axis of each ellipse that is equal to said major axis multiplied by the cosine of angle Alpha generated by lines extending from a midpoint between said outside nonsteering wheel attached to said frame to one of said outside, nonsteering wheels and to the steerable wheel on the same side as said one of said outside, nonsteering wheels and said ellipses have each respective minor axis length that is equal to said major axis length multiplied by the sine of the angle Alpha .

Claim 5

The method of claim 2 wherein said oversteered wheel is the outside wheel on a turn from 0* of steer; said other steerable wheel is the inside wheel on said turn; and said driven ellipse is rotated through a different number of degrees than said driving ellipse.

Claim 6

In a wheeled vehicle having a vehicle frame, a steering system comprising: a. two wheels attached to said frame and separately steerable; b. two steering means, each connected respectively with one of said wheels and operable to steer said wheel in response to a steer signal; c. actuator means connected with said steering means for effecting a turn of said vehicle by generating a steer signal; d. modifier means interposed in connection with said actuator means and with respective said steering means and operable to modify the steer signal from said actuator means to respective said steering means; e. two multiplier means, each being connected with a respective wheel for doubling the degrees through which said wheel has been steered from 0* of steer and adapted to generate a first representation that is a function of twice the degrees of steer for the respective wheel; f. two sensing means, each being connected with a respective multiplier means and operable to effect a respective output signal that is a predetermined function of the respective first representation; g. comparator means connected with said sensing means and said modifier means and operable to effect, in response to the output signals from said sensing means, modification of the steer signal to the respective steering means associated with a steerable wheel that departs from its relative degrees of steer with respect to the other steerable wheel; and h. programmer means connected with one of said sensing means so as to modify what would otherwise be its unmodified output signal to an output signal that is related to the unmodified output signal as the degrees of rotation of the first focal point of a driven ellipse is related to the number of degrees of rotation of the opposite first focal point of a driving ellipse rotating twice the number of degrees that the steerable wheel associated with said one of said sensing means is steered; said ellipses being identical, being placed tangential such that their focal points on their major axes form the apices of a rectangle at the position equivalent to 0* of steer, having a set of first and opposite focal points disposed a fixed distance apart and located at points fixed in space and, having their other Respective and opposite focal points on their major axes in fixed spaced relationship but free to move in a plane.

Claim 7

In a wheeled vehicle having a vehicle frame, a steering system comprising: a. two wheels attached to said frame and separately steerable; b. two steering means, each connected respectively with one of said wheels and operable to steer said wheel in response to a steer signal; c. actuator means connected with said steering means for effecting a turn of said vehicle by generating a steer signal; d. modifier means interposed in connection with said actuator means and with respective said steering means and operable to modify the steer signal from said actuator means to respective said steering means; e. two multiplier means, each being connected with a respective wheel for doubling the degrees through which said wheel has been steered from 0* of steer and adapted to generate a first representation that is a function of twice the degrees of steer for the respective wheel; f. two sensing means, each being connected with a respective multiplier means and operable to effect a respective output signal that is a predetermined function of the respective first representation; g. comparator means connected with said sensing means and said modifier means and operable to effect, in response to the output signals from said sensing means, modification of the steer signal to the respective steering means associated with a steerable wheel that departs from its relative degrees of steer with respect to the other steerable wheel; and h. programmer means connected with one of said sensing means so as to modify what would otherwise be its unmodified output signal to an output signal that is related to the unmodified output signal as the degrees of rotation of the first focal point of a driven ellipse is related to the number of degrees of rotation of the opposite first focal point of a driving ellipse rotating twice the number of degrees that the steerable wheel associated with said one of said sensing means is steered; said ellipses being identical, being placed tangential such that their focal points on their major axes form the apices of a rectangle at the position equivalent to 0* of steer, having a set of first and opposite focal points disposed a fixed distance apart and located at points fixed in space and, having their other Respective and opposite focal points on their major axes in fixed spaced relationship but free to move in a plane.

Claim 8

The steering system of claim 5 wherein said modifier means is an interrupter means that is operable to effect electrical disconnection, upon a suitable signal from said comparator means, of the actuator means from the steering means associated with an oversteered wheel that is being steered more than its relative degrees of steer with respect to the other steerable wheel; and said multiplier means, said programmer means, said sensing means and said comparator means are operable to delineate said oversteered wheel and to effect the suitable signal to said interrupter means.

Claim 9

The steering system of claim 5 wherein said programmer means comprises as said ellipses a first shaft with its center at the focal point of said driving ellipse and having rigid connection means with a first connecting means located with its center at the other focal point on the major axis of said driving ellipse, and a second shaft with its center at the opposite focal point of said driven ellipse and having second rigid connection means with a second connecting means located with its center at the other focal point on the major axis of said driven ellipse; said first connecting means and said second connecting means being maintained in fixed spaced relationship but free to move in a plane, and as opposite focal points by a connecting bar; and meshing means attached to respective said rigid connection means and located at the points in space equivalent to the maximum dimensions of the major axis of each respective ellipse to move said rigid connection means from dead center position and maintain said shafts as opposite focal points.

Claim 10

The steering system of claim 7 wherein the distance between each respective shaft and connecting means along the respective rigid connection means is the major axis of said ellipse multiplied by the cosine of an angle Alpha that is the smallest absolute angle included between a first line which is the axis of a nonsteering wheel attached to said frame and a second line which extends from a steering point on the first line to the pivot axis of the steerable wheel on the same side as said nonsteering wheel, and said shafts and said connecting means are so spaced as to define a minor axis length of said ellipse that is the major axis length multiplied by the sine of the angle Alpha .

Claim 11

The steering system of claim 8 wherein there are two nonsteering wheels have a common axis and said steering point is the midpoint of said common axis between said two nonsteering wheels.

Claim 12

The steering system of claim 7 wherein the effective radius of said respective meshing means is equal to said major axis multiplied by (sine Alpha )2.

Claim 13

The steering system of claim 7 wherein said steering means is an electric motor turning an arrangement of gears connected so as to impart steer to said wheel in response to rotation of said motor; and said actuator means comprises a turn switch mounted on an operator''s console and adapted for generating a steer left signal when moved in one direction and for generating a steer right signal when moved in another direction and a source of electrical power.

Claim 14

The steering system of claim 7 wherein said sensing means comprise a pair of selsyn units, each being positioned responsively to the degrees of steer of its respective steerable wheel; said pair of selsyns being also coconnected electrically to effect zero output signal when a first steerable wheel has its correct relative degrees of steer with respect to the other steerable wheel; and to effect an output signal that indicates with respect to an inlet signal when a first movable element in a first selsyn leads the corresponding second movable element in a second selsyn and when said first movable element lags behind said second movable element.

Claim 15

The steering system of claim 12 wherein said comparator means comprises a phase responsive circuit means for deTermining when said output signal is in phase with said inlet signal and for energizing a first interrupter means, and when said output signal is out of phase with said inlet signal and for energizing a second interrupter means; and a magnitude-responsive circuit means for determining when neither of said interrupter means should be actuated and when both of said interrupter means should be actuated.

Claim 16

The steering system of claim 13 wherein said interrupter means are connected so that one of said interrupter means effects interruption of a steer left signal to the right steerable wheel and a steer right signal to the left steerable wheel and the other of said interrupter means effects interruption of a steer right signal to the right steerable wheel and a steer left signal to the left steerable wheel.

Claim 17

The steering system of claim 13 wherein said phase-responsive circuit comprises parallel rectifying circuits for passing only one polarity signal and connected with respective interrupter means and with respective switch means; only one of said switch means being closed during the positive phase of said alternating current inlet signal, and only the other of said switch means being closed during the negative phase of said alternating current inlet signal, and said magnitude-responsive circuit means comprises a gate means for ultimately actuating one of said interrupter means when a signal magnitude above a minimum threshold is detected, and a shorting means for actuating both said interrupter means when a signal magnitude above a predetermined maximum is detected.

Claim 18

The steering system of claim 15 wherein said magnitude-responsive circuit means includes a latching circuit that latches on when said gate means detects a signal greater than said minimum threshold, and an unlatching circuit that is adapted to render said latching circuit nonconducting when it is conducting and in the absence of said signal on said gate means.

Claim 19

The steering system of claim 7 wherein each steerable wheel is steerable through 360*.