JP5192838B2 - Auto leveling system for vehicle lamps - Google Patents

Description

  The present invention relates to an auto leveling system for a vehicle lamp for automatically controlling an irradiation light axis in a vertical direction of a vehicle lamp that illuminates the front of the vehicle such as a headlamp or a fog lamp of a vehicle such as an automobile.

  Due to the change in the vertical inclination angle (hereinafter referred to as the pitch angle) of the front part of the vehicle body when the automobile is stopped or running, the irradiation optical axis with respect to the road surface of the headlamp is also changed vertically. When the irradiation optical axis is directed upward, other vehicles such as the preceding vehicle and the oncoming vehicle are dazzled, and when the irradiation optical axis is directed downward, the frontal illumination is insufficient and the driver's distance visibility is reduced. To solve this problem, the headlamp's illumination optical axis can be controlled to change up and down with respect to the vehicle body, and a change in the vehicle body pitch angle relative to the reference pitch angle is detected. There has been proposed an auto leveling system in which control is performed so that the change of the angle is canceled and the irradiation optical axis of the headlamp with respect to the road surface coincides with a predetermined aiming angle. In such an automatic leveling system, if the change in the pitch angle is directly applied to the change control of the irradiation optical axis, the irradiation optical axis is changed even by a slight change in the pitch angle during traveling. You may feel it. Therefore, a technique has also been proposed in which filtering is performed to slow down the change in the irradiation optical axis that follows the change in the pitch angle, and the irradiation optical axis is not changed following the change in the high-speed pitch angle. . However, when such filtering is performed, the load applied to the vehicle body from the road surface changes due to acceleration or deceleration of the automobile, and when the pitch angle of the vehicle body changes, the filtering causes a delay in controlling the irradiation optical axis. As a result, proper leveling control may not be possible.

Therefore, in Patent Document 1, the vehicle speed and acceleration (including deceleration, the same applies hereinafter) of the automobile are detected, and filtering is performed when the acceleration is within a predetermined value range, but filtering is not performed when the acceleration is out of the predetermined range. Thus, a technique for avoiding a delay in controlling the irradiation optical axis during acceleration or deceleration has been proposed. Similarly, in Patent Document 2, when the acceleration or deceleration of the automobile is lower than a predetermined determination level, the filtering effect at the time of filtering is strengthened, and when the determination level is exceeded, the filtering effect is weakened to accelerate or decelerate. A technique for avoiding a delay in control of the irradiation optical axis at the time has been proposed.
JP 9-301055 A JP-A-10-250463

  Since the technologies of Patent Documents 1 and 2 do not perform filtering based on the acceleration or speed of the vehicle or weaken the filter effect, the vehicle acceleration exceeds a predetermined level and the pitch angle of the vehicle body has already changed. In this state, it is possible to control to an appropriate irradiation optical axis corresponding to the pitch angle. However, the car body is temporarily suspended, such as when the driver suddenly brakes suddenly while driving at a cruising speed (medium or constant speed), or when the accelerator pedal is momentarily depressed. When it turns downward or upward, the acceleration or speed has not yet exceeded the specified level at that time, so a relatively strong filter effect is functioning, and the irradiation optical axis follows regardless of the change in the pitch angle of the car body. An uncontrolled situation occurs. Therefore, during this time, the state where the irradiation optical axis is downwardly following the vehicle body downwards is continued and the driver's frontal visibility is lowered, or the state where the irradiation optics is upwards following the vehicle body upwards. As a result, dazzling other cars will occur.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an auto leveling system for a vehicle lamp that enables proper control of an irradiation optical axis even when a vehicle body pitch angle is changed during sudden braking or sudden acceleration during cruising. .

The present invention provides the vehicle lamps of the auto-leveling system for change control in the vertical direction irradiation optical axis of the lamp according to the pitch angle of the vehicle, a high speed response of the change control of the irradiation optical axis with respect to the change of the pitch angle, medium Responsiveness change means that can be changed to either a high speed or a low speed is provided, and the responsiveness change means sets the responsiveness to medium speed when the vehicle is stopped, and responsiveness when the vehicle is slower than a predetermined speed. Is set to a high speed, the responsiveness is set to a low speed when the vehicle is traveling at a constant speed higher than a predetermined speed, and the pitch angle is changed more than a predetermined angle when the vehicle is suddenly accelerated or decelerated when the vehicle is at a predetermined speed or higher. The responsiveness is set at a high speed when

According to the present invention, when the vehicle stops, travels at a low speed, travels at a constant speed above a predetermined speed, travels at a speed above a predetermined speed, suddenly accelerates, suddenly decelerates, or changes in pitch angle above a predetermined angle. Since the responsiveness of the responsiveness changing means is changed to the low, medium, and high response speeds according to the difference in the travel mode, the appropriate leveling control according to each travel mode can be realized. That is, by setting the responsiveness to medium speed when the vehicle is stopped, leveling control is performed when the occupant's getting on and off and the like are completed and the pitch angle of the vehicle body is stabilized. By setting the responsiveness to a low speed when running with a stable pitch angle, such as constant speed running at a predetermined speed or higher, leveling control is not frequently performed, and the lighting area is changed by leveling control. Annoyance can be avoided. Responds when driving on uneven roads, braking at low speeds, during sudden acceleration, sudden deceleration, or when the pitch angle changes more than a predetermined angle during acceleration or deceleration. By setting the performance at a high speed, it is possible to realize a high-speed leveling control that can quickly respond to these travels. As a result, it becomes possible to prevent dazzling with respect to other vehicles and to ensure front vehicle far visibility .

  Next, Example 1 of the present invention will be described. FIG. 1 is a schematic diagram showing a schematic configuration of a first embodiment in which the auto leveling system of the present invention is applied to a headlamp of an automobile, and FIG. 2 is a block configuration diagram thereof. Headlamps (headlamps) HL for illuminating the front of the vehicle are arranged on the left and right of the front part of the automobile CAR. In the headlamp HL, the irradiation optical axis can be controlled to be deflected in the vertical direction by a leveling mechanism. For example, as shown in detail in FIG. 2, the headlamp HL has a configuration in which at least a projector-type lamp 23 as a low beam lamp is housed in a lamp housing 20 including a lamp body 21 and a front cover 22. The projector lamp 23 is supported by a bracket 24 that can tilt in the front-rear direction with the upper end as a fulcrum. A leveling actuator 25 in which a drive shaft 25a moves back and forth is connected to the lower part of the bracket 24. By driving the leveling actuator 25, the lower part of the bracket 24 is tilted back and forth, and the tilt angle is controlled. Thus, leveling control of the irradiation optical axis of the projector lamp 24, that is, control for changing the angle formed by the irradiation optical axis of the headlamp HL with respect to the road surface in the vertical direction is possible.

  In FIG. 1, a front vehicle height sensor 11 is provided on the front wheel portion FW of the automobile CAR, and a rear vehicle height sensor 12 is provided on the rear wheel portion RW. It is possible to detect the height from the axle in the front wheel part FW and the rear wheel part RW of the vehicle body BD of the automobile CAR, in other words, the height from the road surface. The front vehicle height sensor 11 and the rear vehicle height sensor 11 are connected to an ECU (Electronic Control Unit) 1 capable of performing necessary calculation and control. The vehicle CAR is provided with a vehicle speed sensor 13 for detecting its own vehicle speed, and this vehicle speed sensor 13 is also connected to the ECU 1. Further, the control end of the ECU 1 is connected to the leveling actuator 25 of the headlamp HL, and the ECU 1 controls the leveling actuator 25 to control the irradiation optical axis of the headlamp HL in the vertical direction as described above. It is possible.

  As shown in FIG. 2, the ECU 1 includes a pitch angle calculation unit 102 that calculates the pitch angle of the vehicle body BD of the automobile CAR from the vehicle heights detected by the front vehicle height sensor 11 and the rear vehicle height sensor 12, and the vehicle speed. A vehicle speed calculation unit 103 that calculates the vehicle speed based on the vehicle speed signal detected by the sensor 13 and an acceleration calculation unit 104 that calculates the acceleration of the vehicle based on a change with time of the calculated vehicle speed are provided. These calculated pitch angle, vehicle speed, and acceleration are each input to the control unit 101. In addition, a filter unit 105 for filtering the pitch angle calculated by the pitch angle calculation unit 102 to change the input / output characteristics of the pitch angle, and a pitch angle output filtered by the filter unit 105 And an actuator driving unit 106 for controlling the leveling actuator 25 to control the irradiation optical axis of the headlamp HL in the vertical direction. The control unit 101 recognizes the input pitch angle over time, calculates a change angle of the recognized pitch angle, compares the change angle with a preset reference angle, and a vehicle speed calculation unit 103. A function for comparing the vehicle speed input from the vehicle with a reference vehicle speed set in advance, and a function for comparing the acceleration input from the acceleration calculation unit 104 with a reference acceleration set in advance. A filter setting function for determining the attitude and running state of the vehicle by performing a calculation with a required algorithm based on the comparison result of the acceleration as described later, and setting the constant of the filter unit 105 based on this determination. Also have.

  Here, the filter unit 105 is configured as a circuit that performs a moving average process on the pitch angles output in time series from the pitch angle calculation unit 102 and outputs the result. As the processing time of the moving average processing, here, processing times corresponding to three types of filter effects of strong effect (5 seconds), medium effect (1 second), and weak effect (0.5) seconds are selected in advance. These three types of processing times are set by the control unit 101. In the filter unit 105, the longer the processing time, the stronger the filter effect becomes, and the slower the output responsiveness to the input pitch angle change. On the contrary, the shorter the processing time, the weaker the filter effect becomes. The response of the output to the pitch angle change becomes faster. In addition, the control unit 101 includes a built-in timer 107, and can manage a time for setting a filter constant to be set in the filter unit 105.

  The leveling control of the irradiation optical axis of the headlamp in the leveling system having the above configuration will be described with reference to the flowchart of FIG. When an ignition switch or the like of an automobile whose description is omitted is turned on, the flow starts, a vehicle speed signal from the vehicle speed sensor 13 is input to the ECU 1, and the ECU 1 calculates the vehicle speed in the vehicle speed calculation unit 103 (S101), and further obtained. The acceleration calculation unit 104 calculates the acceleration from the change of the vehicle speed on the time axis (S102). Further, vehicle height signals from the front vehicle height sensor 11 and the rear vehicle height sensor 12 are input to the ECU 1, and the ECU 1 calculates the pitch angle of the vehicle in the pitch angle calculation unit 102 (S103). These vehicle speed, acceleration, and pitch angle are input to the control unit 101, and the control unit 101 sets the filter constant of the filter unit 105 by the following algorithm. That is, the control unit 101 first determines whether or not “posture sudden change control” is ON as the current state (S104). This “attitude rapid change control” is a processing flow when a brake or an accelerator is instantaneously operated and the pitch angle of the vehicle changes greatly instantaneously when the vehicle is traveling as described later. When it is determined that the “attitude rapid change control” is ON in the current state, it is determined whether or not a preset control time has elapsed based on the elapsed time of the timer 107 (S105). The control is maintained, and when the control time has elapsed, the “posture sudden change control” is canceled (S106).

  On the other hand, when it is determined that the current state is not “posture sudden change control ON”, the vehicle speed and acceleration calculated by the vehicle speed calculation unit 103 and the acceleration calculation unit 104 are referred to, and the vehicle speed and acceleration are referred to as a reference vehicle speed and a reference acceleration region. In comparison with the above, it is determined whether the current traveling state is “rapid acceleration traveling”, “rapid deceleration traveling”, “cruising traveling”, “low speed traveling”, or “stop”. FIG. 4 is a determination map of these travels. When the vehicle speed is 0 to 10 km / h or less as the first reference vehicle speed, the vehicle is “stopped”, and the vehicle speed is higher than this and the second reference vehicle speed is 30 km / h. When the vehicle speed is less than or equal to the degree, “low speed running” is set, and when the vehicle speed is higher than the second reference vehicle speed, “cruising running” is set. In addition, during “cruising”, when the acceleration is larger than the upper limit of the reference acceleration or smaller than the lower limit and is not within the reference acceleration region between these upper and lower limits, "Decelerated travel".

  That is, first, the vehicle speed is compared with the first reference vehicle speed to determine whether or not the vehicle speed is “stop” (S111), and when it is determined to be “stop”, the medium effect filter is selected (S112). When the vehicle speed is higher than the first reference vehicle speed, the vehicle speed is compared with the second reference vehicle speed to determine whether or not the vehicle is running at low speed (S113). When it is determined that the vehicle is running at low speed, the weak effect filter is selected. (S114). When the vehicle speed is higher than the second reference vehicle speed, it is determined as “cruising”, and then it is determined whether the acceleration is sudden acceleration or sudden deceleration (S115). That is, when the acceleration is larger than the upper limit of the reference acceleration region, it is determined as “rapid acceleration traveling”, and when the acceleration is smaller than the lower limit of the reference acceleration region, it is determined as “rapid deceleration traveling”. An effect filter is selected (S116).

  Furthermore, when it is determined in step S115 that the vehicle is not in a sudden acceleration / deceleration state during “cruising”, a change with time in the pitch angle calculated by the pitch angle calculation unit 102 is obtained, and this change in pitch angle is determined as a reference angle. It is determined whether or not it is “posture sudden change” (S117). When it is not “abrupt change in posture”, that is, when the change in pitch angle is within the range of the reference angle, the determination of “cruising” is held, and at this time, the strong effect filter is selected (S118). On the other hand, when it is determined in step S117 that the posture is suddenly changed, that is, when the front part of the vehicle body is suddenly turned upward such that the change in pitch angle is not within the range of the reference angle, or the front part of the vehicle body is downward. When it is pointed, the weak effect filter is selected (S119), and “attitude rapid change control” is immediately turned ON (S120). Here, the reference angle for the determination of “abrupt change in posture” is set in a range of 0.1 ° to 0.5 ° in the vertical direction with respect to the reference pitch angle to be controlled by the leveling system. .

  The control unit 101 sets the constant of the filter unit 105, that is, the moving average processing time, based on the strong, medium, and weak effect filters selected after the above flow. As described above, the processing time is set to 5 seconds for the strong effect filter, 1 second for the medium effect filter, and 0.5 second for the weak effect filter. In response to this, the filter unit 105 performs filtering by taking a moving average for the pitch angle input from the pitch angle calculation unit 102 over time based on the set processing time, and the filtered pitch angle is used as the actuator driving unit 106. The actuator driving unit 106 controls the leveling actuator 25 based on the filtered pitch angle, and controls deflection of the irradiation optical axis of the headlamp HL up and down (S121).

  Accordingly, when the car CAR is “stopped”, the control unit 101 sets the filter unit 105 to a medium effect filter constant, that is, the moving average processing time is set to 1 second. Even when the pitch angle of the vehicle body BD changes due to passengers getting on and off, loading and unloading, etc., the leveling control of the irradiation light axis of the headlamp HL is performed when the change in the pitch angle becomes stable thereafter. become. Therefore, even if the pitch angle slightly fluctuates during this time, the irradiation optical axis of the headlamp HL does not change following this, and the driver, passenger, etc. due to frequent fluctuations in the irradiation optical axis. Does not feel annoying.

  When the car CAR is “running at low speed”, the control unit 101 sets the filter unit 105 to a constant of a weak effect filter, that is, the moving average processing time is set to 0.5 seconds. When the pitch angle of the vehicle body BD changes during traveling on an urban area or a rough road traveling at a low speed, the irradiation optical axis of the headlamp HL is leveled following the pitch angle change in a state close to high sensitivity. Be controlled. Therefore, when the front part of the vehicle body changes upward and downward, the light beam axis of the headlamp HL is leveled and controlled almost in real time, and at the same time, the front and rear visibility is ensured without dazzling other vehicles. It becomes possible to do.

  When the car CAR is “cruising”, the control unit 101 sets the filter unit 105 to a strong effect filter constant, that is, the moving average processing time is set to 5 seconds, so that the response of the filter to the pitch angle change is slow. Even when the pitch angle of the vehicle body changes minutely and at high speed due to road surface unevenness or the like when traveling on a suburb or highway traveling at a relatively high speed, irradiation of the headlamp HL regardless of the change in the pitch angle. The optical axis is rarely leveled and the irradiating optical axis is directed in a substantially constant direction so that the driver does not feel bothered.

  In this “cruising traveling”, when the acceleration changes due to sudden acceleration or sudden deceleration, the control unit 101 determines “rapid acceleration traveling” or “rapid deceleration traveling” when the acceleration exceeds the reference acceleration region. The constant of the filter unit 105 is set to a weak effect filter to increase the responsiveness to a change in pitch angle, and the irradiation optical axis of the headlamp HL is leveled and controlled following the change in the pitch angle accompanying the sudden acceleration or sudden deceleration. Become so. Thereby, when the front part of the vehicle body is directed upward during sudden acceleration, the irradiation optical axis of the headlamp HL is corrected downward to prevent dazzling with respect to other vehicles, and when the front part of the vehicle body is directed downward during sudden deceleration. The irradiation optical axis of the headlamp HL can be corrected upward to ensure the driver's front visibility.

  In this “cruising”, when the accelerator is instantaneously operated and the front part of the vehicle body is suddenly directed upwards, or the brake is operated and the vehicle body front part is suddenly directed downwards. In some cases, the control unit 101 determines “posture sudden change control” when the change angle of the pitch angle exceeds the reference value, and sets the constant of the filter unit 105 to the weak effect filter. That is, the filter unit 105 is set to the constant of the weak effect filter even in a situation where the acceleration of the vehicle does not exceed the reference acceleration region and is not determined as “rapid acceleration travel” or “rapid deceleration travel”. Become. As a result, the responsiveness of the filter to the change in the pitch angle is increased, and the headlamp HL can be used even when the acceleration does not exceed the upper limit value of the reference acceleration region when the front part of the vehicle body changes upward by a predetermined angle by an instantaneous accelerator operation. The irradiating optical axis is rapidly leveled downward to instantly set the time for the irradiating optical axis to be upward and prevent dazzling with respect to other vehicles. Further, when the front part of the vehicle body changes downward by a predetermined angle or more by an instantaneous brake operation, the irradiation light axis of the headlamp HL is instantaneously leveled upward even when the acceleration does not become lower than the lower limit value of the reference acceleration region. The time when the shaft is downward can be instantaneously ensured the driver's front distance visibility. The “posture sudden change control” is turned on only during a control time of 1 to 3 seconds preset by the built-in timer 107 of the control unit 101. Therefore, when the control unit 101 determines in step S104 that the “posture sudden change control”, the “posture sudden change control” is kept on until the control time in the timer 107 elapses (S105). When the time elapses, “posture sudden change control” is turned off (S106).

  Thus, in the system of the first embodiment, when the car CAR is traveling, the filter unit 105 is set as a strong effect filter so that the irradiation optical axis of the headlamp can be set regardless of a minute change in pitch angle. It can be controlled in a predetermined direction, and the driver can be prevented from feeling annoyance due to minute fluctuations in the irradiation optical axis. On the other hand, when the change in the pitch angle of the vehicle body changes by a predetermined angle or more due to an instantaneous accelerator operation or braking operation while traveling, the filter unit 105 is immediately set as a weak effect filter, so the acceleration of the vehicle Even in a situation where does not exceed the reference acceleration region, leveling control of the irradiation optical axis of the headlamp HL that immediately follows the change in the pitch angle of the vehicle body is performed. That is, even when the accelerator operation has not yet exceeded the upper limit value of the reference acceleration area, when the front part of the vehicle body is largely directed upward, the irradiation optical axis of the headlamp HL is quickly leveled and controlled downward. Even if the acceleration is still not lower than the lower limit value of the reference acceleration area even when the brake operation is performed, the irradiation optical axis of the headlamp HL is quickly adjusted when the front part of the vehicle body is greatly directed downward. Further, leveling control can be performed upward to ensure the driver's front visibility.

  This “posture sudden change control” is only during the control time of 1 to 3 seconds as described above, and when the accelerator operation or the brake operation is instantaneous and the operation is immediately released during the control time. Since the pitch angle of the vehicle body is also restored to the previous state, the filter unit 105 is returned to the setting of the strong effect filter of “cruising”. In addition, if the accelerator operation or brake operation continues throughout the control time, even if the “posture sudden change control” ends, the vehicle acceleration usually exceeds the reference acceleration region at that time. Therefore, the setting of the weak effect filter in the filter unit 105 is retained. Further, when the brake operation is continued and the vehicle speed becomes equal to or lower than the second reference vehicle speed, the low speed running state is set and the filter unit 105 is set as a weak effect filter. Therefore, even when “posture sudden change control” is performed, the subsequent leveling control is not affected at all.

  The system of the present invention is not limited to the configuration of the first embodiment, and appropriate modifications are possible. In particular, in the first embodiment, the constant of the filter unit 105 is uniformly set to the weak effect filter in each of “low speed running”, “rapid acceleration / deceleration”, and “attitude change suddenly”. It is also possible to configure the degree to be different. In particular, in order to enhance the leveling control effect in “posture sudden change” which is the main object of the present invention, the constant of the filter unit 105 is set to be more than the degree of the weak effect of “low speed running” or “rapid acceleration / deceleration”. It is possible to set the filter effect to be substantially “0” with the filter effect weakened. With regard to the weak effect filter in “rapid acceleration / deceleration”, the filter effect may be weaker than in “low speed running”. Further, the pitch angle range of 0.1 ° to 0.5 ° and the control time of 1 to 3 seconds in the “posture sudden change control” in the first embodiment are not limited to these specific values. It can be changed as appropriate. Furthermore, the vehicle lamp according to the present invention is not limited to a headlamp, and can be similarly applied as long as it is capable of leveling control by illuminating the front of the vehicle.

It is a conceptual block diagram of Example 1 of this invention. It is a block block diagram of the leveling system of Example 1. It is a flowchart for demonstrating leveling control. It is a speed and acceleration map for explaining a running state.

Explanation of symbols

1 ECU
11 front vehicle height sensor 12 rear vehicle height sensor 13 vehicle speed sensor 20 lamp body 23 projector type lamp 25 leveling actuator 101 control unit 102 pitch angle calculation unit 103 vehicle speed calculation unit 104 acceleration calculation unit 105 filter unit 106 actuator drive unit CAR automobile HL head lamp

Claims (1)

In a vehicle lamp auto-leveling system that controls the illumination optical axis of the lamp to change in the vertical direction according to the pitch angle of the vehicle, the response control of the illumination optical axis change control to the change in the pitch angle is high speed, medium speed, and low speed. Responsiveness change means that can be changed to any one of the response speeds, the responsiveness change means sets the responsiveness to a medium speed when the vehicle is stopped, and increases the responsiveness when the vehicle is slower than a predetermined speed. When the vehicle is traveling at a constant speed equal to or higher than a predetermined speed, the responsiveness is set to a low speed. When the vehicle is higher than the predetermined speed, the vehicle is suddenly accelerated or decelerated, or the pitch angle is changed by a predetermined angle or more. An auto leveling system for a vehicle lamp, characterized in that the responsiveness is set at a high speed .

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