JP2011084150A - Auto-leveling device of head lamp for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect the pitch angle of a vehicle without using a vehicle height sensor and to achieve proper auto-leveling control of a head lamp. <P>SOLUTION: An auto-leveling device includes the head lamp HL illuminating the front of the vehicle, and a leveling ECU 1 calculating the pitch angle when the front and rear parts of the vehicle tilt vertically and performing vertical deflection-control of the optical axis of the head lamp based on the calculated pitch angle. The vehicle includes a plurality of load sensors S1-S5 detecting the load of an occupant and a cargo, and the leveling ECU 1 calculates the pitch angle based on the load detected by the plurality of load sensors S1-S5 and positions of respective load sensors on the vehicle (distance from the center of gravity). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a headlamp that illuminates the front of a vehicle such as an automobile, and in particular, the lamp optical axis of the headlamp according to a change in the inclination of the vehicle so that the light irradiation direction of the headlamp is a constant angle with respect to the road surface. The present invention relates to an auto leveling device for a vehicular lamp that automatically controls a lamp vertically and vertically.

  In recent automobiles, a headlamp system that automatically and appropriately controls the light irradiation direction of the headlamp has been proposed as one of the purposes of improving driving safety. For example, the light irradiation direction of the headlamp corresponding to the change in the pitch angle of the vehicle (vertical vertical inclination angle along the longitudinal direction of the vehicle) accompanying the change in the vehicle occupant and the loaded cargo, that is, the vertical vertical lamp light There is an auto-leveling device that controls the change of the shaft angle so that the light irradiation direction is a constant angle with respect to the road surface regardless of the change in the pitch angle of the automobile. Patent Document 1 includes a vehicle height sensor for detecting vehicle heights at the front and rear wheels of an automobile, and load state detection means for detecting changes in the load state of the vehicle accompanying changes in the occupant or cargo. There has been proposed an auto leveling device that detects the pitch angle of the automobile based on the outputs of the vehicle height sensor and the load state detection means, and automatically controls the lamp optical axis angle of the headlamp based on the detected pitch angle.

  In such an auto-leveling device, if a vehicle height sensor is provided for each of the left and right front wheels and the rear wheels of the vehicle in order to detect the pitch angle, the pitch angle of the vehicle can be accurately obtained. However, the vehicle height sensor is a sensor for measuring the height of the vehicle body with respect to the road surface, and is extremely expensive due to its complicated structure. Therefore, the technique of Patent Document 1 is configured to reduce the number of vehicle height sensors so that an accurate pitch angle can be obtained even when the vehicle height sensor is provided only on either the front wheel or the rear wheel. ing.

JP 2004-196212 A

  In the technique of Patent Document 1, since it is only necessary to equip either one of the front wheels or the rear wheels with a vehicle height sensor, the vehicle height sensor is one on the left or right wheel, or two on the left and right wheels at the maximum. It is sufficient to reduce the cost of the auto leveling device. However, since the vehicle height sensor is expensive as described above, there is a limit to reducing the cost of the auto leveling device as long as the vehicle height sensor is used.

  An object of the present invention is to provide an auto leveling device for a vehicle headlamp that can detect the pitch angle of a vehicle without using a vehicle height sensor at all and can realize an appropriate leveling control of the lamp optical axis. It is.

  An auto leveling device for a vehicle headlamp according to the present invention calculates a headlamp that illuminates at least the front of a vehicle and a pitch angle when the front and rear portions of the vehicle are tilted up and down, and the head is based on the calculated pitch angle. And leveling control means for controlling the deflection of the lamp optical axis of the lamp up and down, and the vehicle has a plurality of load detection means for detecting the load of the occupant and the load, and the leveling control means is detected by the plurality of load detection means. The pitch angle is calculated based on the applied load and the positions of the plurality of load detecting means on the vehicle.

  In the present invention, the load detecting means is constituted by a load sensor disposed on a seat or floor in a vehicle interior of the vehicle. Further, the load sensor may include means for detecting the weight of fuel of the automobile. Furthermore, you may provide the seat position sensor for detecting the position on the vehicle of a load detection means.

  According to the present invention, a plurality of load sensors for detecting the weight of an occupant or a load are provided in the vehicle, and the pitch angle of the vehicle is calculated based on the detection output of these load sensors. Even if the vehicle is not equipped with, the pitch angle of the vehicle can be calculated, and appropriate leveling control of the headlamp becomes possible. Therefore, an expensive vehicle height sensor is not required, and the cost of the auto leveling control device can be reduced.

  In the present invention, the seat position sensor for detecting the position of the load sensor disposed on the seat is provided, so that even when the seat is moved, the pitch angle of the vehicle can be accurately calculated, and suitable auto leveling control is performed. Can be realized.

The conceptual block diagram of the motor vehicle to which this invention is applied. The block diagram which shows the whole structure containing leveling ECU. The schematic diagram which shows the relationship between the reference length of a load sensor, and a tilting moment. 5 is a flowchart of pitch angle calculation or leveling control according to the first embodiment. Tilt moment and pitch angle correlation chart.

(Embodiment 1)
Next, Embodiment 1 of the present invention will be described. FIG. 1 is a conceptual configuration diagram of an automobile CAR to which an auto leveling device of the present invention is applied, and shows an example applied to a five-seater station wagon. The cabin of the automobile CAR provided with the driver's seat and the passenger seat as the front seats FS, rear seat RS is configured as a bench seat for three-seat. Further, the rear part of the passenger compartment is configured as a luggage compartment LR. Headlamps HL to be subjected to auto leveling control according to the present invention are arranged on the left and right sides of the front part of the body CB of the automobile.

In the headlamp HL, a lamp housing 20 is constituted by a lamp body 21 and a front transparent cover 22, and a projector type lamp 23 is housed in the lamp housing 20. The projector lamp 23 is supported by a bracket 24 that can be tilted in the front-rear direction, and the tilting angle can be controlled by the leveling actuator 2. That is, the leveling actuator 2 is fixed to a part of the lamp body 21, and is configured as an actuator having an electromagnetic solenoid structure or an electric motor structure that moves the driving rod 2a forward and backward when a leveling control signal is input. Yes. As a result, the leveling actuator 2 changes the tilt angle of the bracket 24 by the input leveling control signal, tilts the projector-type lamp 23 supported by the bracket 24 in the front-rear direction, and controls the deflection of the optical axis LA of the lamp in the vertical direction. Thus, so-called leveling control is performed.

  The leveling actuator 2 is connected to a leveling ECU 1, which is an electronic control unit for generating the leveling control signal and controlling the leveling actuator 2. Four load sensors S1 to S4 are connected to the leveling ECU 1. That is, one load sensor S1, S2 provided in each of the driver seat and the passenger seat, and one provided substantially in the center of the rear seat in order to detect the total load of the rear seat that can be seated by three persons, or There are three load sensors corresponding to each occupant, here, the former one load sensor S3 and one load sensor S4 disposed at the bottom of the luggage compartment LR. These load sensors S1 to S4 are composed of, for example, strain gauges, and when the occupant is seated on the seat, the load sensors S1 to S4 are deformed together with the seat, resulting in deformation strain, or the strain loaded due to the weight of the load mounted in the luggage compartment, These deformation strains are detected as changes in the resistance value of the electric resistance. Since the configuration of this type of load sensor is already widely known, detailed description thereof is omitted here.

  Further, seat position sensors SP1, SP2 are connected to the leveling ECU 1. That is, although the rear seat RS is fixed to the vehicle body CB, the front seat FS of the driver seat and the passenger seat is configured to be able to move the seat position, that is, the seat position back and forth, and this seat position is detected. For this purpose, a seat position sensor SP1 is provided in the driver's seat and a seat position sensor SP2 is provided in the passenger seat. For the seat position sensors SP1 and SP2, in particular, in the case of an auto position seat that stores and automatically restores the seat position at the driver's seat, the sensor employed in the auto position seat can be used as it is. In addition, even when newly arranged, an inexpensive sensor such as a slide resistance type stroke sensor can be used.

Further, in the first embodiment, the automobile CAR is provided with a gasoline amount sensor S5 for detecting the remaining amount of gasoline in the gasoline tank GT, and this gasoline amount sensor S5 is also connected to the leveling ECU 1. In the present invention, the gasoline amount sensor S5 functions as a load detection means for detecting the weight of the gasoline remaining amount.

  As shown in the block diagram of FIG. 2, the leveling ECU 1 calculates the pitch angle Pθ of the vehicle based on the detected values from the load sensors S1 to S4, the seat position sensors SP1 and SP2, and the gasoline amount sensor S5. Leveling that calculates a vertical deflection angle of the lamp optical axis LA of the headlamp HL based on the pitch angle calculation unit 11 and the calculated pitch angle Pθ and outputs a leveling control signal for controlling the leveling actuator 2. A control signal output unit 12 is provided.

The pitch angle calculation unit 11 stores a reference length along the longitudinal direction of each vehicle from the center of gravity of the vehicle CAR to each of the load sensors S1 to S4 and the gasoline amount sensor S5 as will be described later. Unit 3, a reference length correction unit 4 for correcting the reference length of the driver seat and the passenger seat based on the detection of the seat position sensors SP1 and SP2, and loads detected by the load sensors S1 to S4 and A pitch angle calculation unit 5 that calculates the pitch angle Pθ using the gasoline weight detected by the gasoline amount sensor S5 and the reference length of the reference length storage unit 3 and the correction value from the reference length correction unit 4 is provided.

As schematically shown in FIG. 3, the reference length storage unit 3 measures and defines a centroid position G in the front-rear direction of the car CAR in advance and defines the load sensors S1 to S4 and The distance along the longitudinal direction of the automobile to the position where the gasoline amount sensor S5 is disposed is stored as a reference length. FIG. 3 shows a load sensor S1 for the driver's seat FS1, one load sensor S3 for the rear seat RS, a load sensor S4 for the luggage compartment LR, and angular reference lengths L1, L3. L4. L5 is illustrated. Here, the driver seat and the passenger seat set the reference length for the load sensor when the seat is set at a predetermined position. For example, when the seat position of the driver's seat is changed, the reference length correction unit 4 detects the change length by the seat position sensor SP1, sets the detected length as the correction value La, and uses the correction value La as a reference. By adding or subtracting to the length L1, the distance of the load sensor at the moved position, that is, the correction reference length L1a is calculated. The same applies to the passenger seat.

The pitch angle calculation unit 5 includes a front tilt moment calculation unit 5F that calculates a tilt moment in which the front portion of the vehicle body CB of the car CAR tilts downward with respect to the center of gravity G, and the rear portion of the vehicle body CB is opposite to this. A rear tilt moment calculating unit 5R that calculates a tilt moment tilting downward with respect to the center of gravity G is provided. The front tilting moment calculating unit 5F includes a driver seat tilting moment calculating unit 51 and a passenger seat tilting moment calculating unit 52. For example, the driver seat tilting moment calculating unit 51 is stored in the reference length storage unit 3. A correction reference length L1a obtained by correcting the reference length L1 of the driver's seat with the correction length La detected by the seat position sensor SP1 is obtained, and the correction reference length L1a is multiplied by the load detected by the load sensor S1 to obtain a vehicle center of gravity G. The driver seat tilting moment M1 is calculated and output to the matrix unit 56. The passenger seat tilting moment calculation unit 52 similarly calculates the passenger seat tilting moment M2 and outputs it to the matrix unit 56.

Here, the rear tilting moment calculating unit 5R is composed of three tilting moment calculating units 53 to 55. The rear seat tilting moment calculation unit 53 multiplies the reference length L3 in the load sensor S3 of the rear seat RS stored in the reference length storage unit 3 and the load detected by the load sensor S3 of the rear seat, respectively, to multiply the center of gravity of the vehicle body A rear seat tilting moment M3 with respect to G is calculated. The luggage tilting moment calculating unit 54 multiplies the reference length L4 in the load sensor S4 of the luggage compartment LR stored in the reference length storage unit 3 by the load of the load detected by the load sensor S4, and the luggage compartment tilting moment M4. Is calculated. The gasoline tilting moment calculating unit 55 multiplies the reference length L5 in the gasoline amount sensor S5 of the gasoline tank GT stored in the reference length storage unit 3 by the gasoline amount detected by the gasoline amount sensor S5, that is, the gasoline weight. A gasoline tilting moment M5 is calculated. These rear seats, luggage compartments, and gasoline tilting moments M3 to M5 are output to the matrix unit 56, respectively. The matrix unit 56 adds all the tilting moments M1 to M5, calculates the pitch angle Pθ of the car CAR from the added tilting moment, and outputs it.

  The outline of the leveling control operation in this automatic leveling apparatus will be described with reference to the flowchart of FIG. When an occupant gets into the automobile and sits on a seat while the automobile CAR is stopped, a load corresponding to the weight of the occupant is detected from the load sensors S1 to S3 of each seat. Further, when a load is loaded in the luggage compartment LR, the load of the load is detected from the load sensor S4. Further, the gasoline amount, that is, the gasoline weight is detected from the gasoline amount sensor S5 in the gasoline tank GT (S11). Among the seat load sensors, the load sensors S1 and S2 (S12) detect the seat position from the seat position sensors SP1 and SP2 when the occupant seated in the driver seat and the passenger seat changes the seat position back and forth (S13). ). The pitch angle calculation unit 5 calculates a correction value La of the reference length of the driver's seat from the seat position detected by the reference position correction unit 4 from the seat position sensor SP1 of the driver's seat (S14), and stores it in the reference length storage unit 3 The reference length L1 of the driver's seat being read is read out and corrected to calculate the corrected reference length L1a (S15). For example, when the driver's seat is moved forward, the reference length is corrected to be long, and when the driver's seat is moved backward, the reference length is corrected to be short. Then, the driver seat tilt moment calculation unit 51 multiplies the correction reference length L1a by the load detected from the driver seat load sensor S1 to calculate the driver seat tilt moment M1 (S16). Similarly, the passenger seat tilting moment M2 is calculated for the passenger seat. The obtained driver seat tilting moment M1 and passenger seat tilting moment M2 are added in the matrix portion 56, and this is used as the front tilting moment MF (S17). The front tilting moment MF is a moment that tilts the front of the vehicle body downward due to the weight of the passenger in the front seat. When the passenger does not sit on the passenger seat, the passenger seat tilting moment M2 is “0”.

  On the other hand, in cases other than the load sensors S1 and S2 (S12), the rear seat tilt moment calculation unit 53 reads the rear seat reference length L3 stored in the reference length storage unit 3 (S21), and this reference length L3. Is multiplied by the load detected from the rear seat load sensor S3 to calculate the rear seat tilting moment M3 (S22). Further, the baggage tilting moment calculation unit 54 reads the reference length L4 of the luggage compartment stored in the reference length storage unit 3 (S21), and the weight of the load detected from the load sensor S4 of the luggage compartment is obtained as the reference length L4. And the baggage tilting moment M4 is calculated (S22). Further, the gasoline tilting moment calculating unit 55 reads the reference length L5 of the gasoline tank stored in the reference length storage unit 3 (S21), and this reference length L5. Is multiplied by the gasoline amount detected from the gasoline amount sensor S5 in the gasoline tank GT, that is, the gasoline weight, to calculate a gasoline tilting moment M5 (S22).

Then, the rear seat tilting moment M3, the baggage tilting moment M4, and the gasoline tilting moment M5 are added in the matrix portion 56, and this is set as the rear tilting moment MR (S23). This rearward tilting moment MR is a moment for tilting the rear part of the vehicle body CB downward due to the weight of the passenger in the rear seat, the load in the luggage compartment, and the gasoline in the gasoline tank.

  Accordingly, the matrix unit 56 calculates the total tilting moment of the automobile CAR by setting the front tilting moment MF to a negative value and the rear tilting moment MR to a positive value and adding them together. Then, the pitch angle Pθ of the automobile is calculated by applying this tilt moment to the correlation equation between the tilt moment measured in advance and the pitch angle of the vehicle body (S31). When the tilting moment is negative, the front part of the car CAR is tilted downward, and when it is positive, the front part of the car CAR is tilted upward. As this correlation equation, for example, as shown in FIG. 5, the relationship between the tilting moment and the pitch angle is measured in advance for an actual vehicle, and a chart showing the correlation between the positive and negative values of the tilting moment and the pitch angle based on this measurement. By creating a (characteristic diagram) and applying the obtained tilting moment to this chart, the pitch angle can be easily calculated.

The leveling control signal output unit 12 calculates the vertical deflection angle of the lamp optical axis LA of the headlamp HL based on the pitch angle Pθ output from the pitch angle calculation unit 11, and uses the leveling control signal as the leveling control signal. 2 (S32). As a result, the leveling actuator 2 tilts the bracket 24 based on the leveling control signal, and executes leveling control for deflecting the lamp optical axis LA of the projecting lamp 23 in the vertical direction (S33).

  As described above, in the first embodiment, a plurality of load sensors (including a gasoline amount sensor) S1 to S5 are arranged in the passenger compartment of the automobile, the pitch angle Pθ of the automobile is calculated based on the detection output of these load sensors, and the head Appropriate leveling control of the lamp HL becomes possible. On the other hand, since the pitch angle can be calculated without using an expensive vehicle height sensor, the cost of the auto leveling control device can be reduced.

  Since the first embodiment is applied to an automobile in which the seat positions of the driver seat and the passenger seat can be changed, a seat position sensor is provided in these seats to calculate the pitch angle more accurately. In the case of a car that can change the seat position, a seat position sensor is also installed in the rear seat, and the reference length of the rear seat is corrected based on the detection output of the seat position sensor to calculate the rear seat tilting moment. May be performed.

  On the other hand, the seat position sensor may be omitted because the change range of the seat position is small in the driver's seat and the passenger seat, and the change in the pitch angle accompanying the change in the seat position is often negligible. By omitting the seat position sensor and omitting the reference length correction unit 4 in the leveling ECU 1, further cost reduction of the automatic leveling control device can be realized.

Here, as described above, a plurality of load sensors may be disposed corresponding to each occupant seated in the load sensor disposed in the rear seat. In addition, in the case of an automobile in which a rear seat is folded and a load is loaded, a load sensor is disposed on a floor portion in a vehicle interior corresponding to the bottom surface of the rear seat so as to detect a load including the rear seat. Also good. In other words, whether the occupant is seated on the rear seat or the load is loaded on the folded rear seat, the tilting moment at the rear of the vehicle is detected by detecting the load on the rear seat, and based on this Thus, the pitch angle can be calculated.

  Further, in the case of an automobile with a low frequency of occupant seating such as the rear seat, a seat belt signal may be used to detect the load on the rear seat. Many existing automobiles are provided with a seat belt sensor that detects a state in which the seat belt is worn. Therefore, it is detected that an occupant is seated by the output of the seat belt sensor. In this case, for example, 50 kg as the occupant's body weight is used as a reference weight, and when the occupant is seated, a tilting moment is calculated on the assumption that a load of that weight is mounted, and the pitch angle is calculated. Thereby, the number of load sensors can be reduced and further cost reduction can be realized.

In the first embodiment, the example in which the auto leveling control is executed based on the detection output of the load sensor in a state where the automobile is stopped is described. However, the acceleration / deceleration change of the automobile and the uneven road are also performed when the automobile is running. The pitch angle of the automobile changes as the vehicle travels, and the detection output accompanying the change in gravitational acceleration changes in the load sensor based on this. Therefore, the change in the pitch angle of the automobile can be calculated. Therefore, the present invention can be applied to auto leveling control when the automobile is running. In auto leveling control when the vehicle is running, the detection output of the load sensor may fluctuate slightly as the vehicle runs, and the leveling control may become unstable. Stable auto-leveling control is possible by configuring to absorb fluctuations.

  The present invention can be applied to an auto leveling device configured to calculate the pitch angle of a vehicle and control the optical axis of the headlamp in the vertical vertical direction based on the obtained pitch angle.

1 Leveling ECU
2 Leveling Actuator 11 Pitch Angle Calculation Unit 12 Leveling Control Signal Output Unit 3 Reference Length Storage Unit 4 Reference Length Correction Unit 5 Pitch Angle Calculation Units 51-55 Tilt Moment Calculation Unit 56 Matrix Unit HL Headlamp LA Lamp Optical Axis CAR Automobile CB Car Body S1-S5 Load sensors SP1, SP2 Sheet position sensors L1-L5 Reference length

Claims (4)

  A headlamp that illuminates at least the front of the vehicle, and a leveling that calculates a pitch angle when the front and rear portions of the vehicle are tilted up and down, and controls deflection of the lamp optical axis of the headlamp up and down based on the calculated pitch angle. Control means, and the vehicle includes a plurality of load detection means for detecting a load of an occupant or a load, and the leveling control means includes a load detected by the plurality of load detection means, and a plurality of load detection means. An automatic leveling device for a vehicle headlamp, wherein the pitch angle is calculated based on a position on a vehicle.   2. The vehicle headlamp auto-leveling device according to claim 1, wherein the load detecting means comprises a load sensor disposed on a seat or a floor in a vehicle interior of the vehicle. 3. The vehicle headlamp auto leveling device according to claim 2, wherein the load sensor includes means for detecting the weight of fuel of the automobile. Automatic leveling device for a vehicle headlamp according to any one of claims 1 to 3, characterized in that it comprises a seat position sensor for detecting the position on the vehicle of the load detecting means.

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