Method for steering a steerable vehicle along a guide line marking

Claim 1

A method for steering a steerable vehicle along a guide line marking (L), there being arranged in the vehicle a linear detector (1) rigidly mounted in the vehicle essentially perpendicular to the principal direction of movement of the.vehicle, and whereby the detector is made to sense the guide line marking for determining the-deviation of the marking from an index point in the linear detector, constituting a lateral deviation Ax, two such determinations Δx 1 and A X2 being made at successive different positions along the path, whereby a distance S 1 is measured between the different positions, and the attitude angle ϕ 1 between the marking and the vehicle is calculated from the difference ΔX 2 -ΔX 1 divided by the travelled distance S1 , and said steering is performed by counteracting said lateral deviation and attitude angle, characterized in that a third determination Ax 3 of the lateral deviation is made at a measured distance S2 further travelled that a new attitude angle cp 2 is calculated using ΔX 3 -ΔX 2 and s 2 , and that said values ϕ 1 , ϕ 2 , ΔX 3 , A X2 and a value At 2 for the time passed in traversing distance S2 are entered as values in a steering equation where a, b, c and d are constants and e is a constant e o when ΔX 3 and ϕ 2 have the same sign and is otherwise zero, and the calculated value 6 is a steering angle used for setting a steered wheel (33) of the vehicle.