Device and method for controlling the application height of a road finisher

A method for controlling the height of a vertically adjustable coupling device of a road finisher comprising a tractor and a floating screed, which is attached by means of at least one drawarm to the tractor in such a way that said screed is arranged behind said tractor in the direction in which the road finisher is moving when in operation, a first end of said at least one drawarm being secured to the tractor by means of the vertically adjustable coupling device, and a second end of said at least one drawarm being rigidly secured to the floating screed, said method comprising the following steps which are repeated cyclically in succession:

• a) detecting the height in the area of a screed edge in relation to a reference height, said screed edge being the rear lower edge of the screed in the direction of movement;
• b) detecting the inclination of said at least one drawarm in relation to a reference plane;
• and
• c) controlling the height of the vertically adjustable coupling device on the basis of the detected inclination and the detected height of the rear lower edge of the screed by
• c1) forming a height deviation value on the basis of the detected height and a target height,
• c2) determining a target-inclination-value modification value on the basis of said height deviation value making use of stored tables,
• c3) determining a target inclination value on the basis of said target-inclination-value modification value and a target inclination value of a preceding cycle or a predetermined target inclination value,
• c4) producing a control signal for the vertically adjustable coupling device on the basis of a comparison between the target inclination value and the detected inclination;
• and
• c5) controlling the height of the vertically adjustable coupling device by means of said control signal.