Automatic headlight leveling system for motor vehicles
AssigneeBayerische Motoren Werke Aktiengesellschaft
InventorsFrank Bilz, Peter Lehnert
Life of this patent
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Abstract
A system for automatic headlight leveling control in a motor vehicle has two level sensors which are offset in the longitudinal direction for measuring the vehicle body pitch angle in the form of a level difference. An electronic control unit determines a desired value for the headlight adjustment as a function of the first derivative of the directly measured or further processed level difference. In one embodiment of the invention, electronic control unit determines a static level difference and a dynamic level difference, and the desired value is determined as a function of the first derivative or the second derivative of the dynamic level difference.
Claims9
An automatic leveling system for vehicle headlights comprising:
- at least two level sensors which are offset in a longitudinal direction of the vehicle body for measuring vehicle body pitch angle in the form of a level difference;
- and
- an electronic control unit for determining a target value for headlight adjustment as a function of the measured level difference;
- wherein the control unit determines the target value as a function of the first derivative of at least one of the measured level difference and a further processed level difference.
A method of controlling an inclination angle of vehicle headlights, comprising:
- measuring time varying vehicle pitch;
- calculating a first derivative, with respect to time, of measured vehicle pitch;
- averaging said vehicle pitch over a first time period, wherein said first time period is determined as a function of said calculated first derivative;
- and
- generating a headlight adjustment control signal as a function of averaged vehicle pitch determined in said averaging step.
A method of controlling an inclination angle of vehicle headlights, comprising:
- measuring time varying vehicle pitch;
- determining a static vehicle pitch by averaging said time varying vehicle pitch over a first time period;
- determining a dynamic vehicle pitch by averaging said time variable vehicle pitch over a second time period which is significantly shorter than said first time period;
- calculating first and second derivatives, with respect to time, of measured time variable vehicle pitch;
- and
- generating headlight adjustment control signals as a function of said static and dynamic averages and at least said first derivative.
Dependencies are inferred from the claim text.