Headlight optical axis control apparatus

Patent metadata

Field	Value
Publication number	US-2018257540-A1
Application number	US-201515533145-A
Country	US
Kind code	A1
Filing date	Mar 12, 2015
Priority date	Mar 12, 2015
Publication date	Sep 13, 2018
Grant date	—

Abstract

A headlight optical axis control apparatus calculates an inclination angle of a vehicle with respect to a road surface from a ratio of a difference between acceleration signals in the front-and-rear direction measured at two time points (kn, kn+1) to a difference between acceleration signals in the up-and-down direction measured at the two time points (kn, kn+1), the two time points being in the vicinity of a time when the attitude of a vehicle body becomes equivalent to a stationary state, in a period from a time when the travelling vehicle stops to a time when the vehicle body comes to a halt.

First claim

1 . A headlight optical axis control apparatus comprising a controller which calculates an inclination angle of a vehicle with respect to a road surface on a basis of acceleration signals in an up-and-down direction and in a front-and-rear direction, measured by an acceleration sensor mounted on the vehicle and which generates control signals to operate a headlight optical axis,
wherein the controller calculates the inclination angle of the vehicle with respect to the road surface from a ratio of a difference between the acceleration signals in the up-and-down direction measured at two time points to a difference between the acceleration signals in the front-and-rear direction measured at the two time points, the two time points being selected from a period ranging from a time immediately before attitude of a vehicle body is identical to a stationary state to a time immediately after the attitude of the vehicle body is identical to the stationary state, from a time when the travelling vehicle stops to a time when the vehicle body comes to a halt.

2 . The headlight optical axis control apparatus according to claim 1 , wherein the acceleration signals measured at the two time points from the time when the travelling vehicle stops to the time when the vehicle body comes to a halt are acceleration signals caused by vibration of the vehicle body from a time when wheels of the vehicle stop to the time when the vehicle body comes to a halt.

3 . The headlight optical axis control apparatus according to claim 2 , wherein the time when the attitude of the vehicle body is identical to the stationary state corresponds to a time when the vehicle body passes through a center of amplitude in the up-and-down direction during a period in which the vehicle body vibrates after the wheels of the vehicle stop.

4 . The headlight optical axis control apparatus according to claim 3 , wherein the time when the vehicle body passes through the center of the amplitude in the up-and-down direction during the period in which the vehicle body vibrates after the wheels of the vehicle stop corresponds to
a time when the acceleration signal in the up-and-down direction is at zero, a time when jerk that is obtained by differentiating the acceleration signal in the up-and-down direction reaches a local maximum or a local minimum a time when moving velocity that is obtained by integrating the acceleration signal in the up-and-down direction reaches a local maximum or a local minimum, or a time when a moving amount that is obtained by integrating the moving velocity is a central value between a local maximum value of the moving amount and a local minimum value of the moving amount or a mean value of the moving amount.

5 . The headlight optical axis control apparatus according to claim 1 , wherein the acceleration sensor is integrally constituted.

6 . The headlight optical axis control apparatus according to claim 1 , wherein vehicle-mounted electrical equipment mounted on the vehicle is integrally constituted.

Assignees

• Mitsubishi Electric Corp

Inventors

• Ohsawa Takashi
• Tsujita Wataru

Classifications

• B60Q2300/114

  Vehicle acceleration or deceleration · CPC title

• B60Q2300/132

  Pitch · CPC title

• B60Q1/115 Primary

  by electric means {(details of the electric drive components, e.g. motors, shafts, ball joints B60Q1/076)} · CPC title

• B60Q2300/324

  Road inclination, e.g. uphill or downhill · CPC title

• G01M11/062

  using an indicator mounted on the head-light · CPC title