JP4031925B2 - Light distribution control system for vehicular lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To change light distribution for a light distribution control system of a lighting fixture for a vehicle without giving a driver a sense of incongruity even when the vehicle is running on a climbing road and a sloped road. SOLUTION: A main control circuit of the light distribution control system of the lighting fixture for the vehicle calculates an inclination of a traveling road at a step 112 while the vehicle is running and controls light distribution by selecting either mode based on the calculated inclination. When the traveling road is a plain road, light distribution control by a normal mode is practiced at a step 116. When the traveling road is a climbing road, light distribution control by a climbing road mode is practiced at a step 118 and light distribution of a group of lamps is switched at timing which is later than that of practice of light distribution control by a normal mode. When the traveling road is a sloped road, light distribution control by a sloped road mode is practiced at a step 120 and light distribution of a group of lamps is switched at timing which is earlier than that of practice of light distribution control by a normal mode.

Description

[0001]
[Industrial application fields]
The present invention relates to a light distribution control system that controls light distribution of a vehicle lamp such as a headlight.
[0002]
[Prior art]
Conventionally, as this type of system, for example, as shown in Japanese Patent Publication No. 7-71908, a map database storing a road map and the current position of the vehicle are specified on the road stored in the map database. Controlling the light distribution of the vehicle lamp attached to the front part of the vehicle according to the current position of the vehicle on the road stored in the map database specified by the vehicle position specifying means And a light distribution control means for controlling the illumination area of the lamp according to the traveling direction of the vehicle or the traveling environment during the traveling of the vehicle, so that the driver's visual field is always favorably secured. Are known.
[0003]
[Problems to be solved by the invention]
However, in the above conventional system, the light distribution control means switches the light distribution when changing the light distribution of the vehicle lamp according to the current position of the vehicle specified by the vehicle position specifying means. Regardless of the slope, it was always performed at a uniform timing. Therefore, if the light distribution is changed while traveling on an uphill or downhill road, the driver feels that switching of the light distribution is too early during traveling on the uphill road, and the light distribution during traveling on the downhill road. I felt that switching was too slow, and I felt uncomfortable about each.
[0004]
SUMMARY OF THE INVENTION
An object of the present invention is to provide a light distribution system for a vehicular lamp that can change a light distribution without giving a sense of incongruity to a driver even when the vehicle is traveling on an uphill road or a downhill road. .
[0005]
A structural feature of the present invention is that a light distribution control system for a vehicle lamp provided with the map database, vehicle position specifying means, and light distribution control means is provided with a gradient detection means for detecting the gradient of the traveling path of the vehicle. When the light distribution control means changes the light distribution of the vehicular lamp, the light distribution switching timing is adjusted according to the gradient of the vehicle travel path detected by the gradient detection means, and the vehicle travel path is an uphill road In such a case, the timing for starting the switching of the light distribution is delayed, and when the traveling path of the vehicle is a downhill road, the timing for starting the switching of the light distribution is advanced. According to this, even when the light distribution is changed during traveling on the uphill road or downhill road, the light distribution switching timing is adjusted according to the gradient of the traveling road of the vehicle. Giving a sense of incongruity.
[0006]
Note that one of the control during traveling on the uphill road and the control during traveling on the downhill road may be omitted, and only one of them may be employed. This also makes it possible to expect the effects of the present invention accordingly.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The vehicle lamp light distribution control system shown in FIG. 1 controls the light distribution of the lamp group 10 by the light distribution control circuit 20, and partially uses a navigation (route guidance) system 30 mounted on the vehicle. Configured.
[0008]
The lamp group 10 includes a plurality of lamps such as a head lamp, a fog lamp, and a corner lamp attached to the front portion of the vehicle, and irradiates the side from the front of the vehicle. Alternatively, the entire light distribution can be changed by changing the amount of light. The light distribution control circuit 20 controls the light distribution of the lamp group 10 according to the instruction signal output from the navigation control circuit 31 of the navigation system 30.
[0009]
The navigation system 30 includes an input / output unit 32, a map database 33, a GPS receiver 34, a direction sensor 35, a vehicle speed sensor 36, and a VICS receiver 37 that are connected to the main control circuit 31. The input / output unit 32 is operated by a driver at the time of instructing a destination, and outputs necessary guidance information to the driver by screen display or voice. The map database 33 stores road positions and shapes as a plurality of nodes (nodes) and a plurality of links (line segments) connecting the nodes.
[0010]
A GPS (Global Positioning System) receiver 34 receives a GPS signal representing the current position of a vehicle transmitted from a GPS satellite. The direction sensor 35 detects a direction in which the vehicle is facing. The vehicle speed sensor 36 detects the speed of the vehicle. A VICS (Vehicle Information & Communication System) receiver 37 receives a VICS signal representing road traffic information such as a traffic amount of a traveling road of the vehicle by road-to-vehicle communication using FM multiplexing, radio wave beacons, optical beacons, and the like. .
[0011]
The main control circuit 31 includes an instruction operation by the driver in the input / output unit 32, map data stored in the map database 33, GPS and VICS signals received by the GPS and VICS receivers 34 and 37, and sensors 35, A program corresponding to the flowchart shown in FIG. 2 is executed on the basis of the detection by 36 to perform processing as a navigation system, determine the light distribution of the lamp group 10 and output an instruction signal to the light distribution control circuit 20. Is. The main control circuit 31 is also connected with a lighting switch 41 for instructing lighting of the lamp group 10 and a throttle opening sensor 43 for detecting the opening of the throttle valve of the engine.
[0012]
Next, the operation of the light distribution control system configured as described above will be described with reference to the flowchart of FIG. Initially, when an ignition switch of a vehicle (not shown) is turned on, the main control circuit 31 starts executing the program in step 100, and thereafter continues to repeatedly execute the circulation process including steps 102 to 120.
[0013]
First, in step 102, the main control circuit 31 inputs a signal indicating the driver's instruction operation, map data, GPS and VICS signals, and detection signals. In step 104, map matching processing is executed. Map matching processing refers to any road represented by map data by calculating the current position of the vehicle based on the input GPS signal and each detection signal and matching the calculated current position with the map data. This is a process for identifying the current position of the vehicle. This process is repeatedly executed during the circulation process without stopping the progress of the program, and the calculated current position of the vehicle is not consistent with the map data, and the vehicle is placed on the road represented by the map data. Even when the current position cannot be specified, the program can proceed to the next step 106 and subsequent steps without completing the process.
[0014]
In step 106, a route to the destination of the vehicle is calculated based on the current position of the vehicle specified by the map matching process, the signal indicating the driver's input operation, the map data, and the VICS signal. Then, processing as a navigation system (navigation processing) such as guidance to the driver is executed.
[0015]
In step 108, it is determined whether the map matching process is completed. At this time, if the map matching process is incomplete, that is, if the calculated current position of the vehicle does not match the map data and the current position of the vehicle cannot be specified on the road represented by the map data, the main control The circuit 31 returns the program to step 102 under the determination of “NO”. On the other hand, if the map matching process is completed at this time, the main control circuit 31 advances the program to step 110 and subsequent steps based on the determination of “YES”.
[0016]
In step 110, it is determined whether or not the lighting switch 41 is on. At this time, if the driver is not instructed to turn on the lamp group 10 and the lighting switch 41 is in the OFF state, the main control circuit 31 determines “NO” and returns the program to step 102. On the other hand, if lighting of the lamp group 10 is instructed by the driver at this time and the lighting switch 41 is in the ON state, the main control circuit 31 determines “YES” and advances the program to step 112 and the subsequent steps to distribute the light. Start the process for control.
[0017]
In step 112, the correlation between the vehicle speed detected by the vehicle speed sensor 36 and the opening degree of the throttle valve of the engine detected by the throttle opening degree sensor 43 is compared with the basic output map of the vehicle, so that the gradient of the traveling path of the vehicle is obtained. Is calculated. In step 114, based on the calculated gradient, it is determined whether the vehicle traveling road is a flat road having almost no gradient, an uphill road, or a downhill road, and the program is branched.
[0018]
If it is determined that the traveling road is a flat road, the main control circuit 31 executes light distribution control in the normal mode in step 116. Specifically, this process is executed as follows.
[0019]
First, as shown in FIG. 3 (a), the road stored in the map database 33 based on the current position of the vehicle specified by the map matching process in step 104 and the vehicle speed detected by the vehicle speed sensor 36. The predicted position of the vehicle after a predetermined time (for example, 2.5 seconds) is specified. And while updating the predicted position at any time as the vehicle advances, it continues to determine whether or not the predicted position has reached a point that requires light distribution change control. Here, the point requiring the light distribution change control is, for example, a point where the road shape changes such as a point approaching the curve from the straight road or a point exiting from the curve to the straight road, an intersection, or the map database 33 in advance. This is a point where a travel area of a vehicle (for example, an urban area, a suburb, a highway, etc.) defined on the map data is switched.
[0020]
However, this process is repeatedly executed during the cyclic process consisting of the steps 102 to 120 without stopping the progress of the program. If the newly specified predicted position has not reached the light distribution change control point, the program is temporarily returned to step 102 without executing the light distribution change control, and the next execution of step 116 is performed. Sometimes the predicted position is updated and the same determination is made again. By repeating this, the main control circuit 31 waits for the predicted position of the vehicle to reach the light distribution change control point.
[0021]
If the predicted position reaches the light distribution change control point during the circulation process, the main control circuit 31 determines an appropriate light distribution for the same point, and performs a light distribution control on a signal indicating the determined light distribution. Output to the circuit 20. In response to this, the light distribution control circuit 20 controls the lamp group 10 to switch the light distribution.
[0022]
On the other hand, when it is determined in step 114 that the traveling road is an uphill road, the main control circuit 31 executes light distribution control in the uphill road mode in step 118. Even in the same mode, the main control circuit 31 specifies the predicted position, determines the light distribution when the predicted position reaches the required light distribution change control point, and outputs the light distribution instruction signal. In this case, as shown in FIG. 3B, the predicted position is compared with the light distribution control in the normal mode in step 116, the position closer to the current position of the vehicle, that is, the vehicle is earlier (for example, 1 .5 seconds later) Specify the position to be reached. Therefore, when the light distribution control in the uphill road mode is executed, the light distribution of the lamp group 10 is switched at a later timing than in the light distribution control in the normal mode.
[0023]
On the other hand, if it is determined in step 114 that the traveling road is a downhill road, the main control circuit 31 executes light distribution control in the downhill road mode in step 120. Even in the same mode, the main control circuit 31 specifies the predicted position, determines the light distribution when the predicted position reaches the required light distribution change control point, and outputs the light distribution instruction signal. In this case, as shown in FIG. 3C, the predicted position is compared with the light distribution control in the normal mode in step 116, a position far from the current position of the vehicle, that is, the vehicle is slow (for example, 3 .5 seconds later) Specify the position to be reached. Therefore, when the light distribution control in the downhill road mode is executed, the light distribution of the lamp group 10 is switched at an earlier timing than in the execution of the light distribution control in the normal mode.
[0024]
In each of the above cases, the light distribution is switched gradually and continuously. For example, when the optical axis α of the lamp group 10 is swung to the left and right, the light distribution is switched by gradually increasing the swing angle α of the optical axis after the light distribution switching start timing (see FIG. 3). ).
[0025]
As described above, in the above-described embodiment, the light distribution control processing in each mode of steps 116 to 120 is selected and the light distribution switching timing is adjusted according to the gradient of the vehicle traveling path calculated in step 112. It has come to be. Therefore, even when the light distribution is changed during traveling on the uphill road or downhill road, it is avoided that the driver feels uncomfortable.
[0026]
In the above embodiment, the relationship between the vehicle speed detected by the vehicle speed sensor 36 and the throttle valve opening of the engine detected by the throttle opening sensor 43 is defined as the vehicle basic output map. Instead of this, instead of this, as indicated by a two-dot chain line in FIG. 1, a gradient sensor 44 for detecting the vehicle gradient is separately provided and detected by the same gradient sensor 44. The vehicle gradient may be used for the determination in step 112 as the gradient of the traveling road. Alternatively, road gradient information may be stored in the map database 33 in advance. Alternatively, the difference between the reference acceleration on a flat road estimated from the engine output and the actual acceleration of the actual vehicle is calculated. If the actual acceleration is greater than the reference acceleration by a predetermined value or more, it is determined as a downhill road, If it is smaller than the value, it may be determined that the road is an uphill road.
[0027]
Further, in the above embodiment, the three types of light distribution control of the normal mode, the uphill road mode, and the downhill road mode are selectively executed based on the gradient of the traveling road. The division may be further subdivided according to the magnitude of the gradient. Further, the predicted position may be directly determined from the magnitude of the gradient, and the light distribution switching timing may be arbitrarily adjusted according to the magnitude of the gradient. Further, one of the uphill road mode and the downhill road mode may be omitted, and only one of the control during the uphill road traveling and the control during the downhill road traveling may be employed. This also makes it possible to expect the effects of the present invention accordingly.
[Brief description of the drawings]
FIG. 1 is an overall schematic diagram of a light distribution control system for a vehicular lamp according to an embodiment of the present invention.
FIG. 2 is a flowchart showing a program executed by the main control circuit of FIG.
3A shows the light distribution switching start timing while traveling on a flat road, FIG. 3B shows the light distribution switching start timing when traveling on an uphill road, and FIG. 3C shows the light distribution switching timing when traveling on a downhill road. It is explanatory drawing showing the switching start timing of light.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Lamp group, 20 ... Light distribution control circuit, 30 ... Navigation system, 31 ... Main control circuit, 33 ... Map database, 44 ... Gradient sensor.

Claims (3)

A map database that stores road maps;
Vehicle position specifying means for specifying the current position of the vehicle on the road stored in the map database;
Light distribution control means for controlling the light distribution of the lamps attached to the front of the vehicle according to the current position of the vehicle on the road stored in the map database specified by the vehicle position specifying means In a light distribution control system for a vehicle lamp,
Provided with a gradient detecting means for detecting the gradient of the traveling path of the vehicle,
The light distribution control means adjusts the light distribution switching timing according to the gradient of the vehicle travel path detected by the gradient detection means when changing the light distribution of the vehicular lamp. When the vehicle is an uphill road, the timing for starting the switching of the light distribution is delayed, and when the traveling path of the vehicle is a downhill road, the timing for starting the switching of the light distribution is advanced. Light distribution control system for lighting equipment. A map database that stores road maps;
Vehicle position specifying means for specifying the current position of the vehicle on the road stored in the map database;
Light distribution control means for controlling the light distribution of the lamps attached to the front of the vehicle according to the current position of the vehicle on the road stored in the map database specified by the vehicle position specifying means In a light distribution control system for a vehicle lamp,
Provided with a gradient detecting means for detecting the gradient of the traveling path of the vehicle,
The light distribution control means adjusts the light distribution switching timing according to the gradient of the vehicle travel path detected by the gradient detection means when changing the light distribution of the vehicular lamp. When the vehicle is an uphill road, the light distribution control system for a vehicular lamp is characterized in that the light distribution switching start timing is delayed as compared with a flat road. A map database that stores road maps;
Vehicle position specifying means for specifying the current position of the vehicle on the road stored in the map database;
Light distribution control means for controlling the light distribution of the lamps attached to the front of the vehicle according to the current position of the vehicle on the road stored in the map database specified by the vehicle position specifying means In a light distribution control system for a vehicle lamp,
Provided with a gradient detecting means for detecting the gradient of the traveling path of the vehicle,
The light distribution control means adjusts the light distribution switching timing according to the gradient of the vehicle travel path detected by the gradient detection means when changing the light distribution of the vehicular lamp. When the vehicle is a downhill road, the light distribution control system for a vehicular lamp is characterized in that the timing for starting the switching of the light distribution is advanced compared to a flat road.

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