JPH0474219B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a headlight control device for a vehicle that automatically changes the irradiation range of the headlight in accordance with light rays from the front of the vehicle.

(Prior Art) A light sensor that receives light from the front of a vehicle and generates a light reception signal, an adjustment means that adjusts the irradiation range of the headlight, and a light sensor and adjustment means that adjusts the irradiation range according to the light reception signal. A vehicle headlight control device is known which includes a control circuit provided between the vehicle headlight control device and the control circuit. Such a device has the advantage that the vehicle headlights do not dazzle oncoming or preceding vehicles.

In conventional devices, the pointing angle of the optical sensor is fixed.

(Problems to be Solved by the Invention) Therefore, on a wide road (for example, two lanes on each side) or on a slope, an oncoming vehicle or a vehicle in front that should be detected may be out of the range of the pointing angle. For this reason, if we want to expand the directivity angle of the optical sensor,
A problem arises in that the sensor becomes sensitive to ambient light from street lights and the like.

Therefore, the present invention can detect an oncoming vehicle or a vehicle in front without being sensitive to ambient light as much as possible.
Another object of the present invention is to provide a headlight control device for a vehicle that can accurately adjust the irradiation range of a headlight.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides the above-mentioned vehicle headlight control device with a signal generating means for generating a running state signal according to the running state of the vehicle. , and control means for substantially changing the pointing range of the optical sensor in accordance with the driving state signal.

In implementation, the signal generating means may, for example, generate a signal representative of the speed of the vehicle or a signal representative of the angle of inclination of the vehicle.

The control means may change the orientation angle of the optical sensor in the left-right direction or in the vertical direction. In this case, although the optical sensor or the optical system associated therewith may be configured movably, it is more desirable to configure it stationary. For example, an optical sensor can generate multiple detection signals corresponding to multiple detection areas in front of the vehicle,
The control means may be configured to discard the detection signal corresponding to the pointing angle to be selected.

(Effects) With the above-described configuration, the control means changes the pointing range of the optical sensor in accordance with the driving state signal generated by the signal generation means. As a result, the optical sensor receives light from in front of the vehicle in a pointing range that is appropriate for the vehicle's driving conditions, so it receives as little external light as possible, or misses the oncoming vehicle or the vehicle in front as much as possible. This can contribute to accurate adjustment of the irradiation range of the headlight.

(Example) The present invention will be described below based on an example shown in the drawings. In FIG. 1, numeral 10 is a lens for condensing the headlight light of an oncoming vehicle and the taillight light of a vehicle in front. Reference numeral 20 denotes an optical sensor composed of a plurality of photoelectric elements (in this embodiment, as shown in FIG. 2, 30 photoelectric elements with vertical i=3 and horizontal j=10) arranged two-dimensionally on the same plane. , a plurality of photoelectric signals Sij (in the embodiment, ij
= 11 to 30).

Reference numeral 30 denotes an input processing circuit which sequentially switches the photoelectric signal Sij using an analog multiplexer according to a control signal Cij from a control circuit 50, which will be described later, and converts it into a voltage Vij at a predetermined amplification factor.
40 is an AD conversion circuit which converts each output Vij from the input processing circuit 30 into a digital value Dij and outputs the digital value Dij.

50 is a control circuit that executes digital arithmetic processing by software according to a predetermined program, and is connected to a microcomputer CUP, ROM,
The calculations shown in FIGS. 3A and B, which will be described later, include a RAM, an I/O circuit section, a clock generation section, etc., and supply a stable voltage of 5V from an on-board battery via a stabilizing power supply circuit (none of which is shown). Execute processing.

Reference numeral 60 denotes a drive circuit for driving the headlight, and in response to the output OUT from the control circuit 50, when the OUT signal is a Hi level signal, the transistor and relay are turned on, and the low beam filament 72 of the vehicle headlight 70 is turned on. In addition, the OUT
If the signal is a LOW level signal, the transistor and relay will be in the OFF state and the vehicle headlight 70 will be turned off.
The high beam filament 71 lights up. 80
is a vehicle speed sensor (not shown, see JP-A-55-87955)
A distance signal SP of 60 pulses is generated for each rotation of the speedometer cable. 90 is an example of Tokkai Sho.
This is a slope sensor that generates a slope signal SL proportional to the slope of the vehicle, as shown in No. 59-42409 "Slope Detector". The vehicle running state detection means 100 is composed of a vehicle speed sensor 80 and an inclination sensor 90.

Here, the optical sensor 20 is arranged on a plane separated by the focal point f of the lens 10 so that the center line of the lens coincides with the center of the photoelectric elements in i=2 rows. The light receiving range (light receiving direction angle) is uniquely determined by the diameter φ of the lens 10, the focal point f, and the size of each photoelectric element. In this embodiment, the upper and lower light receiving directivity angles of each photoelectric element are set to ±1°, and the left and right light receiving directivity angles are set to 1.3°.
Therefore, for the optical sensor 20 as a whole, the left and right light receiving directivity angles are at most 13 degrees, and the top and bottom light receiving directivity angles are ±3 degrees.
The operation of the above configuration will be explained with reference to the calculation flowcharts A and B in FIG. 3. In FIG. 3, in step 101, the registers, counters, latches, etc. of the microcomputer in the control circuit 50 are initialized, and the process proceeds to step 102. In step 102, it is determined whether or not the timer has elapsed for 125 msec. If 125 msec has not elapsed, step 102 is repeatedly executed.

When 125 msec has elapsed, the determination becomes YES and the process proceeds to step 103. In step 103, the timer is reset and the process proceeds to step 104.

In step 104, the variable n is set to 1, and the flags Fi (j=1 to 10 in the embodiment) corresponding to the left and right photoelectric elements are all set to zero. In step 105, the tilt signal SL from the tilt sensor 90 is read. In step 106, the vehicle inclination angle determined based on the inclination signal SL is set to a predetermined value (in the embodiment, ±
1°) or more, that is, when the vehicle is traveling uphill or accelerating, the process proceeds to step 107 and selects the photoelectric element array with i=1 in order to set the directivity angle of the optical sensor 20 downward. Further, if the vehicle inclination angle is equal to or greater than a predetermined value (-1° in the embodiment) in step 106, that is, if the vehicle is traveling downhill or decelerating, a step is executed to set the directivity angle of the optical sensor 20 upward. Proceed to step 109 and select the photoelectric element array with i=3. Further, if the vehicle inclination angle is within a predetermined value (±1° in the embodiment) in step 106, the beam direction angle of the optical sensor 20 is set at the center, so the process proceeds to step 108 and selects the photoelectric element array with i=2.

In step 110, the distance signal SP from the vehicle speed sensor 80 is read. In step 111, it is determined whether the vehicle speed determined based on the distance signal SP is equal to or higher than a predetermined value (80 km/h in the embodiment), and if the determination is
If YES, it is determined that the vehicle is traveling on a wide road such as an expressway, and the process proceeds to step 114.
If the determination in step 111 is NO, it is determined that the vehicle is traveling on a general road, and the process proceeds to step 112.

In step 112, the variable i=n+2 is calculated, and the process proceeds to step 113, where it is determined whether or not j is 8 or less.
If the determination is YES, that is, j of the optical sensor 20 is 8.
If the th photoelectric element is also not selected, the process advances to step 116. In step 114, the variable j=n is calculated, and in step 115, it is determined whether or not j is 10 or less. If the determination is YES, that is, j of the optical sensor 20 is
=If the 10th photoelectric element has not been selected yet, proceed to step 116. Step 113 and Step
If the determination in step 115 is NO, that is, if the input processing for a plurality of predetermined photoelectric elements of the optical sensor 20 has been completed, the process proceeds to step 122.

In step 116, the control signal Cij is output to the input processing circuit 30. In step 117, the AD-converted digital value Dij of the photoelectric element indicated by the control signal Cij is read. In step 118, it is determined whether the digital value Dij is greater than a constant K1, and if the determination is YES, that is, if the ijth photoelectric element of the optical sensor 20 receives a predetermined amount of light or more, the process proceeds to step 119. Set flag Fj indicated by variable j to “1”
and proceed to step 121. Judgment is made in step 118.
If NO, that is, if the ij-th photoelectric element of the photosensor 20 does not receive more than a predetermined amount of light, the process proceeds to step 120, where the flag Fj indicated by the variable j is set to "0", and the process proceeds to step 121.

In step 121, 1 is added to variable n, and the process returns to step 111, where the above calculation process is repeated until variable j becomes 9 or 11. At step 113, variable j becomes 9,
If variable j becomes 11 in step 115, that is, once every 125 ms, the program proceeds to step 122, checks the state of flag Fi (j = 1 to 10) indicated by variable j, and determines whether all flags Fj are "0" or If three or more consecutive flags Fj of variable j are "1" (for example, f ₃ , F ₄ , F ₅ are "1"), that is, the optical sensor 20 is not receiving more than a predetermined amount of light, or If the above amount of light is being received over a wide range (this is caused by the reflection of the own vehicle's headlights from a guardrail or the like), the process proceeds to step 123. If one or more of the flags Fj is “1” in step 122 (however,
(Except when three or more consecutive flags Fj of variable j are "1"), that is, when the optical sensor 20 receives light of a predetermined level or more with three or more consecutive non-continuous one or more photoelectric elements, the process proceeds to step 124. move on.

In step 123, the OUT signal is set to "0", that is, in order to turn the vehicle headlights 70 into high beams 71.
Outputs a LOW level signal and returns to step 102. In step 124, the OUT signal is output as "1", that is, a Hi level signal in order to set the vehicle headlight 70 to the low beam 72, and the process returns to step 102.

FIG. 4 shows the change in the vertical direction angle. This shows the case where

Figure 5 shows changes in the steering angle in the left and right directions.
If the vehicle speed is less than Km/hour and the range of j=1 to 8 is selected, and B is the vehicle speed is 80Km/hour or more,
The cases where the range of j=1 to 10 is selected are shown below.

In the above embodiment, only the digital value Dij of a specific photoelectric element is read based on the outputs of the vehicle speed sensor 80 and the tilt sensor 90, but after reading all the digital values, the vehicle headlight 70 is read based on the distance signal SP and the tilt signal SL. It is also possible to perform filament control for low beam and high beam. In addition, if light is detected by a certain photoelectric element determined by the tilt signal SL and the distance SP, and the light is no longer detected after 125ms, the tilt signal
By checking the flags on the photoelectric elements above and below the SL regardless of the SL, the light source will be detected when the vehicle in front enters a slope or approaches a vehicle with a high taillight position (bus, etc.) or a low vehicle (light vehicle, etc.) I can deal with losing sight of things. Also, similarly, the vehicle speed is 80
If the speed is less than Km/h, the end of the optical sensor 20, i.e., j=3
Or, if the photoelectric element indicated by j = 8 is detecting light and then stops detecting light after 125 ms, the photoelectric elements on the left and right of it (if j = 3, j = 2, if j = 8, then j = 9)
By checking the flag, it is possible to avoid losing sight of the light source when the vehicle in front travels on a curved road.

Furthermore, in the above embodiment, the number of photoelectric elements of the optical sensor 0 was set to 30 (i = 3, j = 10), but i may be increased or decreased by increasing or decreasing the vertical receiving directivity angle, or j can be increased or decreased by increasing or decreasing the horizontal directivity angle. It may be increased or decreased. Furthermore, the size of each photoelectric element may be changed as long as it can distinguish between the reflection of the own vehicle's light and the light from the vehicle, and satisfies the upper and lower light receiving directivity angles.

Although a microcomputer type control circuit 50 is shown, the same thing can be done using a hard logic circuit.

In addition, although a case has been described in which the vehicle speed sensor 80 and the tilt sensor 90 are used simultaneously to change the vertical and horizontal light receiving finger pointing angles, the left and right light receiving finger pointing angles are changed stepwise depending on the speed using only the vehicle speed sensor 80. Alternatively, it may be possible to use only the inclination sensor 90 and to change the angle in stages according to the inclination of the upper and lower light-receiving directivity angles.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention;
FIG. 2 is a schematic diagram showing an example of the arrangement of photoelectric elements in the optical sensor 20 shown in FIG.
A series of flowcharts showing the control program of the illustrated microcomputer 50, FIG.
B, C and FIGS. 5A and 5B are explanatory diagrams of changes in the pointing angle of the optical sensor. 20... Optical sensor, 50... Microcomputer, 80... Vehicle speed sensor, 90... Tilt sensor.

Claims (1)

[Claims] 1. An optical sensor that receives light from the front of the vehicle and generates a light reception signal, an adjustment means that adjusts the irradiation range of the headlight, and an adjustment means between the optical sensor and the adjustment means that adjusts the irradiation range according to the light reception signal. a control circuit provided in the vehicle, comprising a signal generating means for generating a driving condition signal according to the driving condition of the vehicle, and control for substantially changing the pointing range angle of the optical sensor according to the driving condition signal. A vehicle headlight control device comprising means.