JPS6351898B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicle light control device that automatically turns on and off lights based on whether the vehicle is running or stopping and the brightness or darkness of the outside illuminance.

Conventional vehicle light control devices include, for example, a first
The vehicle light control device shown in the figure consists of an optical sensor 1 using a photoelectric element such as a CdS or a photodiode, a rise delay circuit 2, a comparator 3, and a drive circuit 4. It is roughly structured.

For example, as the illuminance outside the vehicle decreases after sunset, the output voltage of the optical sensor 1 increases, and when it exceeds the reference voltage Vs at the comparator 3 (corresponding to the illuminance level outside the vehicle that requires the lights to be turned on). The output of the comparator 3 becomes "H" and the transistor 6 of the drive circuit 4 is turned on, thereby driving the relay 7 and lighting the light 8.

Further, the rise delay circuit 2 delays the turning off of the light 8 when the illuminance outside the vehicle suddenly increases, and the diode 5 delays the turning on of the light 8 when the illuminance outside the vehicle suddenly decreases. It is done quickly and without delay.

As a result, for example, when driving at night and passing through a place where the illuminance outside the vehicle changes repeatedly due to street lights, the phenomenon where the lights repeatedly flash (hereinafter referred to as hunting phenomenon) can be prevented to some extent. It can be prevented.

Furthermore, although not shown, in addition to the above configuration, a circuit for detecting running/stopping of the vehicle is provided,
Generally, the light is turned on only when the outside illuminance is reduced and the vehicle is running and the vehicle is running.

However, in the case of the above-mentioned vehicle light control device, the rise delay circuit 2 is configured to prevent light hunting, and therefore, as mentioned above, when street lights are installed at night, When the vehicle is traveling slowly on a road due to traffic congestion, the time it takes to pass under a street light exceeds the delay time in the delay circuit 2, causing a problem of hunting of the lights 8.

Therefore, the present applicant has previously proposed a vehicle light control device that eliminates the hunting phenomenon described above during slow driving.

This is configured to capture external illuminance data from an optical sensor and determine the brightness or darkness of the external illuminance every time the vehicle travels a certain distance (for example, the interval between street lights) based on the output of the vehicle speed sensor. This is what I did.

However, since the above-mentioned vehicle light control device is configured to sample the illumination data outside the vehicle based on the output of the vehicle speed sensor, if an abnormality occurs in the vehicle speed sensor system, the illuminance data outside the vehicle will be Sampling of illuminance data stops,
There is a risk that the write control may not be performed correctly.

This invention was made in view of the above circumstances, and when an abnormality occurs in the vehicle speed sensor system,
Since then, the sampling of outside illumination data based on the output of the vehicle speed sensor has been changed to sampling at fixed time intervals, so even if the output of the vehicle speed sensor is interrupted, the ability to determine the brightness of the illuminance outside the vehicle can be maintained. An object of the present invention is to provide a vehicle light control device that can maintain the following conditions.

Embodiments of the vehicle light control device according to the present invention will be described in detail below with reference to FIG. 2 and subsequent drawings.

FIG. 2 is a block diagram showing an embodiment of a vehicle light control device according to the present invention.

In the figure, a CPU 11 is, for example, a one-chip microcomputer installed in this type of vehicle, and executes a system program stored in a ROM 12, and uses a memory 13 composed of a RAM etc. to store various variable data. It is used as an area to perform light control according to the present invention and various other vehicle controls.

A pulse train with a frequency proportional to the vehicle speed output from the vehicle speed sensor 14 is input to the input port of the CPU 11, and the CPU
interface 15 for supplying interrupt signals to 11
, a timer 16 that supplies an interrupt signal to the CPU 11 at fixed time intervals, and an A/D converter 17 that A/D converts the illuminance level outside the vehicle detected by the optical sensor 1 and supplies it to the CPU 11. An ON signal from a throttle switch 18 that detects an accelerator depression operation is supplied via an interface 19.

A write control signal is supplied from the output port to the drive circuit 4 via the buffer 20.

FIGS. 3a and 3b are flowcharts showing the contents of interrupt processing executed by the CPU 11 in response to interrupt signals from the interface 15 and timer 16, respectively.

In the case of an interrupt process performed based on a pulse train from the vehicle speed sensor 14, as shown in FIG. 3a,
When the interrupt processing is started, first, in step 21, "0" is stored in the flag F in the memory 13. This flag F is set to "1" when an abnormality occurs in the vehicle speed sensor system.

The abnormality detection process for detecting whether or not an abnormality has occurred in the vehicle speed sensor system is executed within the CPU 11, and although not shown, for example, each pulse period in the pulse train supplied from the vehicle speed sensor 14 is The system calculates the deceleration rate of the vehicle speed from the difference between successive pulse cycles, and determines whether this deceleration rate exceeds a preset maximum deceleration rate (for example, the deceleration rate when suddenly stopping while driving at medium to high speeds). is subtracted and compared, and if the deceleration rate is larger than the maximum deceleration rate, it is determined that an abnormality has occurred in the vehicle speed sensor system, or when the pulse train is not supplied from the vehicle speed sensor 14, the throttle switch 18 Arithmetic processing that counts the time during which the ON signal is supplied, and determines that there is an abnormality in the vehicle speed sensor system when this count value exceeds a predetermined reference value (for example, the pulse period of the above pulse train when traveling at 5 km/h) The system is configured to detect abnormalities in the vehicle speed sensor system.

Next, proceed to step 22 and convert A/D converter 1.
The illuminance data outside the vehicle supplied from step 7 is taken in, and in step 23, the brightness or darkness of the illuminance outside the vehicle is determined. That is, by subtracting and comparing the captured external illuminance data with threshold data stored in memory in advance (corresponding to the illuminance level at which the lights need to be turned on), the above-mentioned external illuminance data is determined as the threshold data. If it is smaller, a determination signal corresponding to "dark" is output, and if it is larger, a determination signal corresponding to "bright" is output.

Then, the process proceeds to step 24, and when it is determined in step 23 that the light is "dark", a light lighting instruction signal is output, and this lighting instruction signal is supplied to the drive circuit 4, so that the light 8 is automatically turned on ( If it is lit, it will continue to be lit (the same applies hereinafter).

If "bright" is determined in step 23, a light extinguishing instruction signal is supplied to the drive circuit 4, and the light 8 is automatically extinguished (if it is already extinguished, it continues to be extinguished; the same applies hereinafter).

On the other hand, in the case of interrupt processing by the timer 16, as shown in FIG. 3b, when the interrupt processing is started,
At step 25, it is determined whether or not "1" is set in the flag F. If it is "0", all of the following steps 26, 27, and 28 are jumped and the process returns to normal processing.

If an abnormality is detected in the abnormality detection process of the vehicle speed sensor system and the flag F is set to "1", the process proceeds to step 26, where the outside illuminance data is fetched from the A/D converter 17 and the Processing similar to the arithmetic processing performed in step 23 is performed to determine the brightness and darkness of the illuminance outside the vehicle, and the process proceeds to step 28, where, similar to the processing in step 24, the light is 8 automatic lighting/extinguishing is performed.

As mentioned above, the light control is normally performed by interrupt processing based on the output of the vehicle speed sensor 14, and during the period when a pulse train is not supplied from the vehicle speed sensor 14 due to an abnormality in the vehicle speed sensor system, the period shown in FIG. 3a is Interrupt processing is no longer performed, and write control is performed by interrupt processing at fixed time intervals by the timer 16 in FIG. 3b.

In this embodiment, the timer 16 is operated at all times, but the timer 16 may be started when an abnormality in the vehicle speed sensor system is detected.

Further, it can also be used as a timer that measures the cycle of pulses from the vehicle speed sensor 14 used to detect an abnormality in the vehicle speed sensor system, or as a timer that measures the time that the throttle switch 18 is in the ON state.

Furthermore, by using a one-chip microcomputer with a built-in timer, the above-mentioned various counts can be easily switched using software, and the circuit configuration can be simplified.

As explained above, in the vehicle light control device of the present invention, when an abnormality occurs in the vehicle speed sensor system, the sampling of the vehicle exterior illuminance data that has been performed based on the output of the vehicle speed sensor is performed at a constant rate. By configuring the system to switch to hourly sampling, even if the supply of output from the vehicle speed sensor is interrupted, the function of determining the brightness of the outside illumination can be maintained, improving safety in light control. be able to.

[Brief explanation of the drawing]

FIG. 1 is a schematic circuit configuration diagram showing a conventional vehicle light control device, FIG. 2 is a block diagram showing a schematic configuration of an embodiment of a vehicle light control device according to the present invention, and FIG. 3 is a block diagram of the same embodiment. 2 is a flowchart showing processing contents according to the present invention in a system program executed by a CPU. 1...Light sensor, 8...Light, 11...
CPU, 12...ROM, 13...Memory, 15...
...Interface, 16...Timer, F...Flag.

Claims (1)

[Scope of Claims] 1. Main acquisition control means for acquiring vehicle exterior illuminance data from an optical sensor that detects vehicle exterior illuminance every time the vehicle travels a certain distance based on the output of the vehicle speed sensor; a vehicle speed sensor abnormality detection means for detecting; when an abnormality in the vehicle speed sensor system is detected, a sub-taking control means for acquiring the vehicle exterior illuminance data at regular time intervals; A vehicle light control device comprising: a brightness/darkness determination unit that determines whether or not the level is below a set level; and a light drive unit that turns on/off the light based on the brightness/darkness determination result. .