Vehicle Control Systems and Methods

Abstract

Systems for controlling the speed and direction of vehicles such as tractors, including vehicles that have low to zero turning radius capability. Systems include steering and speed coordination systems that control the direction and speed of rotation of vehicle drive units.

1 . A vehicle control system for a vehicle having a steering wheel, left and right front steerable non-driving wheels, and left and right rear drivable wheels, the vehicle control system comprising:
 a first gear pair that turns the right front steerable non-driving wheel following a steering input from a steering wheel corresponding to a zero-radius turn from a straight-ahead position;   a second gear pair that turns the left front steerable non-driving wheel following the steering input;   a pair of links, each link having a slot that is straight over substantially all of the length of the slot;   a first follower positioned in the slot of one of the links, the first follower movable in an arc following the steering input;   a second follower positioned in the slot of the other of the links, the second follower movable in an arc following the steering input;   a pair of speed cams, one speed cam coupled to one of the links and the other speed cam coupled to the other of the links, each speed cam including a curved slot and being pivotable following a speed input from a speed pedal;   where pivoting of the speed cams following the speed input while the first and second followers are in respective positions corresponding to the zero-radius turn will cause each link to move in a plane that is parallel to any flat surface on which vehicle is positioned, causing the left and right drivable wheels to rotate in opposite directions.