Method and apparatus to regulate illumination range of a motor vehicle

• US 5,191,530 A
• Filed: 07/30/1991
• Issued: 03/02/1993
• Est. Priority Date: 08/06/1990
• Status: Expired due to Fees

• Current Assignee: HELLA KG Hueck & Co.
• Original Assignee: HELLA KG Hueck & Co.
• Inventors: Hussmann, Micha, Hufnagel, Joachim
• Primary Examiner(s): Chin, Gary
• Application Number:
  US07/737,725
• Time in Patent Office: 581 Days
• Field of Search: 364/424.05, 307/10.8, 315/77, 315/82, 362/71, 362/285, 362/286, 362/277, 362/428
• US Class Current: 701/49
• CPC Class Codes: B60Q 1/115 by electric means details of the electric drive components, e.g. motors, shafts, ball joints B60Q1/076
• CPC Class Codes: B60Q 2300/112 Vehicle speed
• CPC Class Codes: B60Q 2300/114 Vehicle acceleration or deceleration
• CPC Class Codes: B60Q 2300/132 Pitch

Abstract

In a method and apparatus to regulate the illumination range of a motor vehicle in which, at a position on a front axle and at a position on a rear axle, signals are measured which are dependent upon the relative position of a motor-vehicle body to the front axle and the rear axle, with a difference formation between the signal from the front axle and that of the rear axle being accomplished with a resulting difference signal, as a nominal-value signal, being filtered to a first average-value formation. The time for the first average-value formation is determined by a first filter (F1) time constant with positions of adjusting elements being regulated when the first filtered nominal-value deviates from a predetermined, or set, value. In order to be able to recognize inclination changes of the motor-vehicle body which cannot be attributed to changes in load or road surface unevenness, simultaneously with the first average-value formation, a second average-value formation of the nominal-value signal, with a second short filter (F2) time constant, and a third average-value formation of the nominal-value signal, with a third long filter (F3), time constant takes place. The thusly produced second filtered nominal-value signal is compared with the thusly produced third filtered nominal-value signal and upon the existence of a difference between the second filtered nominal-value signal and the third filtered nominal-value signal the first average-value formation is interrupted and upon termination of the difference is again turned on.

Claims

1. In a method of regulating an illumination range of a motor vehicle of a type comprising the steps of developing front-axle and rear-axle signals which respectively depend upon a relative position of a motor-vehicle body to a front axle and a rear axle of the motor vehicle, forming a resulting difference signal indicative of a difference between the front-axle signal and the rear axle signal, filtering and resulting difference signal, as a nominal-value signal, to form a first average value as a function of time, wherein said time for development of the first, average, nominal, value is determined by a first filter time constant, and regulating positions of lamp adjusting elements when the first, filtered average nominal-value deviates from a predetermined value, wherein the improvement:

simultaneously with said formation of the first average value, filtering the resulting difference signal to form a second average value of the nominal-value signal with a filter having a second filter time constant and filtering the resulting difference signal to form a third average value of the nominal-value signal with a third filter time constant;

comparing and thusly produced second nominal average-value signal with the thusly produced third average-value signal, and, upon the presence of a difference between the second average-value signal and the third average-value signal, interrupting use of the first average value formation for regulating positions of said lamp adjusting elements and, upon a termination of said difference, reinstating use thereof for regulating positions of said lamp adjusting elements.

2. Method as in claim 1 wherein the second filter time constant is shorter in time than said first filter time constant and the third filter time constant is longer than the first filter time constant.

3. Method as in claim 2 wherein the first average value formation upon the presence of the difference between the second average-value signal and the third average-value signal is interrupted when the motor vehicle has exceeded a minimum speed and no substantial positive or negative acceleration of the motor vehicle is present.

4. Method as in claim 3 wherein upon the motor vehicle exceeding a minimum border value for said positive or said negative acceleration of the motor vehicle the first average-value formation is interrupted and when the acceleration no longer exceeds the minimum border value the interruption is terminated.

5. Apparatus for regulating the illumination range of a motor vehicle with a front axle sender and a rear axle sender which produces signals in dependence upon the position of a motor vehicle body to the front axle and the rear axle, said apparatus having a nominal-value developer which develops a difference signal indicative of a difference between signals from the front axle sender and the rear axle sender, having at least one first filter which receives said difference signal and which carries out an averaging thereof to create a filtered nominal-value as a function of time, and having a regulator which receives the filtered nominal value and, in dependence upon the filtered nominal value, regulates positions of adjusting elements for adjusting an illumination range of the motor vehicle, said apparatus further including the improvement:

that a switching device is connected between said nominal-value developer and the first filter, having a first filter time constant;

that the nominal-value developer is coupled to a second filter having a second filter time constant and to a third filter having a third filter time constant;

that the second filter and the third filter are coupled to a subtractor;

that the subtractor is coupled with a curve recognition device; and

that the curve recognition device opens the switching device upon the presence of a difference between the signals from the second filter and the third filter and upon termination of the difference again closes the switching device.

6. Apparatus as in claim 5 wherein the second filter time constant is shorter than the first filter time constant and the third filter time constant is longer than the first filter time constant.

7. Apparatus according to claim 6 wherein the curve recognition device, is coupled with a speed signal sender and wherein the curve recognition device has a speed threshold value device for recognizing when a speed indicated by said speed signal sender passes a predetermined speed threshold and modifies operation of the switching device in response thereto.

8. Apparatus according to claim 7 and further comprising an acceleration signal former which is coupled with an acceleration threshold value device for opening the switching device only when an acceleration indicated by said acceleration signal former further exceeds a threshold value of said threshold value device.