Device for steering a steerable wheeled vehicle

Claim 1

A method for steering a steerable vehicle along a linear path marking (1), there being arranged in the vehicle a linear detector (3) rigidly mounted in the vehicle essentially perpendicular to the principal direction of movement of the vehicle, said vehicle including at least one wheel providing a steering angle for the vehicle, comprising: sensing the linear path marking at two successive positions along the path of said vehicle for determining the deviation of the linear marking from an index point on the linear detector, constituting two lateral deviation determinations Δx 1 and Δx 2 ; measuring the distance Δs between the different positions; measuring the attitude angle ψ 1 between the linear path marking and the vehicle from the difference Δx 2 -Δx 1 divided by the travelled distance s; determining a third lateral deviation Δx 3 at a measured distance s 3 from the last of said successive positions; determining a new attitude angle ψ 2 using Δx 3 -Δx 2 and s 3 ; and entering said values ψ 1 , ψhd 2, Δx 3 , Δx 2 and a value Δt 3 for the time passed in traversing distance s 3 in a steering equation ##EQU5## where a, b, c and d are constants and e is a constant e o when Δx 3 and ψ 2 have the same sign and is otherwise zero, whereby the calculated value δ is used for setting said steered one wheel of the vehicle; and steering said vehicle one wheel to provide a steering angle δ.

Claim 2

A method for steering a steerable vehicle along a linear path marking (1), there being arranged in the vehicle a linear detector (3) rigidly mounted in the vehicle essentially perpendicular to the principal direction of movement of the vehicle, said vehicle including at least one wheel providing a steering angle for the vehicle, comprising: sensing the linear path marking at two successive positions along the path of said vehicle for determining the deviation of the linear marking from an index point on the linear detector, constituting two lateral deviation determinations Δx 1 and Δx 2 ; measuring the distance Δs between the different positions; measuring the attitude angle ψ 1 between the linear path marking and the vehicle from the difference Δx 2 -Δx 1 divided by the travelled distance s; determining a third lateral deviation Δx 3 at a measured distance s 3 from the last of said successive positions; determining a new attitude angle ψ 2 using Δx 3 -Δx 2 and s 3 ; and entering said values ψ 1 , ψhd 2, Δx 3 , Δx 2 and a value Δt 3 for the time passed in traversing distance s 3 in a steering equation ##EQU5## where a, b, c and d are constants and e is a constant e o when Δx 3 and ψ 2 have the same sign and is otherwise zero, whereby the calculated value δ is used for setting said steered one wheel of the vehicle; and steering said vehicle one wheel to provide a steering angle δ.