JP2004196212A - Irradiating direction control device of vehicular lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase accuracy and suppress the rise of cost on the irradiating direction control of a lamp according to a variation in the attitude of the vehicle by detecting a variation in the load distribution of the vehicle to switch a control line even if a vehicle height detecting means is installed on the axle part of either of the front wheels and rear wheels of the vehicle. <P>SOLUTION: This irradiating direction control device 1 of the vehicle lamp varying the irradiating direction of the lamp according to the attitude of the vehicle in the forwarding direction of the vehicle comprises the vehicle height detection means 2 for detecting a variation in the height of the axle part of the front wheels or rear wheels of the vehicle and a driving means 6 for facing the irradiating light of the lamp in a specified direction. The device also comprises a load distribution detection means 3 for detecting the load distribution of the vehicle according to the variation of the number of occupants and the weight of cargos on the vehicle. The detection means detects a variation in load of the vehicle according to the riding conditions and loading conditions of the vehicle, and switches the control line or the inclination or intercept of the control line corresponding to a present load state. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention detects a vehicle height displacement with respect to an axle portion of a front wheel or a rear wheel of a vehicle, and determines an occupant arrangement, a loaded state of luggage, and the like, thereby controlling an irradiation direction of a vehicular lamp in accordance with a change in posture of the vehicle. This is related to technology for appropriately performing the above.
[0002]
[Prior art]
When the vehicle stops or travels, the change in the vehicle attitude is canceled in order to prevent the direction of the irradiation light of the lamp attached to the vehicle from becoming unstable due to the change in the attitude in the vehicle traveling direction. A device that constantly corrects the irradiation direction of a lamp (a so-called auto-leveling device) is known.
[0003]
For example, based on a detection signal obtained by a vehicle height detecting means attached to an axle portion of a rear wheel, a change in a pitch angle related to a vehicle posture is obtained, and the irradiation direction of a lamp is controlled accordingly. The following devices have been proposed (for example, refer to Patent Literature 1, Patent Literature 2, and Patent Literature 3).
[0004]
[Patent Document 1]
JP-A-10-226271
[Patent Document 2]
JP-A-10-230777
[Patent Document 3]
JP 2001-80409 A
[0005]
[Problems to be solved by the invention]
However, since the attitude of the vehicle is affected by the riding conditions of the occupants and the loading conditions of the luggage, it is necessary to realize appropriate control characteristics according to the load state of the vehicle. There are certain limits to the improvement of For example, there is a problem that the control and the configuration are complicated in increasing the accuracy.
[0006]
Therefore, the present invention detects a change in the load distribution in the vehicle and switches the control line even when the vehicle height detecting means is provided only for one of the front wheels and the rear wheels of the vehicle. Accordingly, it is an object to accurately control the irradiation direction according to a change in the attitude of the vehicle and to avoid complicating the configuration and the like.
[0007]
[Means for Solving the Problems]
The present invention has the following configuration to solve the above-mentioned problems.
[0008]
Vehicle height detecting means for detecting a vehicle height displacement related to the axle portion of the front wheel or the rear wheel of the vehicle;
Driving means for changing the direction of the illumination optical axis of the lamp;
Load state detecting means for detecting a change in the load state of the vehicle due to a change in the occupant or the load;
Irradiation control means for transmitting a correction signal relating to the irradiation direction of the lamp to the drive means in accordance with signals from the vehicle height detection means and the load state detection means;
[0009]
Then, in the irradiation control means, when the vehicle height displacement detected by the vehicle height detecting means is “Δh” and the pitch angle of the vehicle with respect to the vehicle height displacement is “p”, the correlation between them is p−Δh A plurality of control lines each having a characteristic represented by a primary expression are prepared in advance for each load state of the vehicle, and a control line corresponding to the current load state or an inclination related to the control line is determined based on a signal from the load state detection unit. Alternatively, the intercept on the p-axis is switched, and the pitch angle is calculated from the vehicle height displacement according to the control line.
[0010]
Therefore, according to the present invention, the load state detecting means grasps the load state due to the occupant or the load, and selectively prepares a control line prepared for the state or an inclination or a slice on the p-axis according to the control line. By simply switching to the above, the irradiation direction of the lamp can be controlled according to the pitch angle based on the detection signal of the vehicle height displacement.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 shows an example of a basic configuration of an irradiation direction control device for a vehicle lamp according to the present invention.
[0012]
The irradiation direction control device 1 includes a vehicle height detection unit 2, a load state detection unit 3, a vehicle speed detection unit 4, an irradiation control unit 5, and a driving unit 6. The lamp 7 whose irradiation direction is controlled by the irradiation control unit 5 via the driving unit 6 includes, for example, a head lamp, a fog lamp, a cornering lamp, and the like in the case of a vehicle lamp.
[0013]
The vehicle height detecting means 2 is provided for detecting a vehicle height displacement related to an axle portion of a front wheel or a rear wheel of the vehicle, and the detection signal includes basic information for grasping a stopping posture and a running posture of the vehicle. Is done. For example, there is a method in which a vehicle height sensor is provided as the vehicle height detecting means 2 for detecting the vertical fluctuation of the axle portion of the front wheel or the rear wheel to detect the amount of expansion and contraction of the suspension.
[0014]
The load state detecting means 3 is provided for detecting a change in the load distribution of the vehicle due to a change in the occupant or the load in the vehicle. That is, since the vehicle attitude is affected by the load distribution of the vehicle, it is necessary to grasp the load distribution of the vehicle in order to accurately calculate the vehicle attitude based on the detection signal of the vehicle height detecting means 2.
[0015]
In detecting the load distribution, it is preferable to perform detection separately for a human load change and a physical load change from the viewpoint of processing efficiency as described below.
[0016]
(A) Load change depending on the number and arrangement of occupants
(B) Load change due to the weight and arrangement of the load.
[0017]
First, (A) is a change in load due to a change in occupant position and weight in the vehicle. For example, information can be directly obtained by detecting whether or not a person is sitting on the seat by using a seating sensor or a weight detection sensor provided on the seat, or detecting the weight of the seated person. In addition, whether or not a person is sitting on the seat is detected by a non-contact type sensor using light (such as infrared rays) or sound waves, or a sensor (including a buckle sensor or the like) is used to determine whether or not a seat belt is worn. And an average value is assumed for the weight of a person (for example, whether a person is an adult or a child is determined based on the sitting height of a seated person, and a predetermined weight value is determined in accordance with the determination result. Use, etc.), the load can be calculated indirectly. Alternatively, when the boarding position is determined like a car, it can be determined whether or not a person is sitting in the passenger seat based on a door opening / closing signal and an opening / closing time interval. Although the occupant weight can be detected as a continuous amount, it is preferable to perform stepwise range division in terms of simplification of control.
[0018]
Regarding the above (B), a sensor for detecting the position and weight of the loaded luggage may be attached to the vehicle. For example, a load change can be directly detected by detecting the presence or absence of a load applied to a trunk room or a bed of a vehicle and the amount of the load. At this time, the weight of the load can be detected as a continuous amount, but it is preferable to perform stepwise range division in terms of simplification of control.
[0019]
Since the signals from the vehicle height detecting means 2 and the load state detecting means 3 are sent to the irradiation control means 5, a correction signal relating to the direction of the irradiation optical axis of the lamp 7 is sent to the driving means 6 in accordance with these signals. . At that time, leveling control is performed in the following procedure.
[0020]
(1) When the vehicle height displacement detected by the vehicle height detecting means 2 is described as “Δh” and the inclination angle (pitch angle) of the vehicle attitude with respect to the displacement is described as “p”, the correlation between them is p−Δh A plurality of control lines whose characteristics are expressed by linear expressions are prepared in advance for each load state of the vehicle.
(2) On the basis of a signal from the load state detecting means 3, the control line corresponding to the current load state is switched, or the slope or the intercept on the p-axis of the control line is switched.
[0021]
(3) Based on the control line of (2), a pitch angle related to the vehicle attitude is calculated from the detection signal of the vehicle height detection means 2.
[0022]
(4) A correction signal for controlling the direction of the irradiation optical axis with respect to the pitch angle of (3) is sent to the driving means 6. Thereby, the irradiation optical axis of the lamp 7 is tilted in the vertical direction (or in the vertical plane).
[0023]
The stopping posture and the running posture of the vehicle can be obtained by calculating the pitch angle from the height change of the axle portion before and after the vehicle, but only for one of the front wheels or the rear wheels of the vehicle. If the vehicle height detecting means is not provided, or if only the vehicle height detecting means provided for one of the front wheels or the rear wheels is functioning normally due to a failure of the vehicle height detecting means, the vehicle It is necessary to define the correlation between the high displacement and the vehicle attitude in advance, and the procedure for that is (1).
[0024]
FIG. 2 illustrates the two control lines g1 and g2, with the horizontal axis representing the vehicle height displacement “Δh” and the vertical axis representing the pitch angle “p”. The point “Q1” located at the origin represents a situation in which one driver is in the vehicle (passenger car), and performs an initial adjustment (a so-called aiming adjustment) of the illumination optical axis of the lamp at the time of shipment. By doing so, it is set to the origin position.
[0025]
The meaning of each point shown in the figure is as follows.
[0026]
・ Point “Q2” = indicates a situation where one driver is on board and one is on the passenger seat.
・ Point "Q3" = Indicates the situation where the capacity (5 people) is on board
・ Point “Q4” = indicates a situation where the capacity (5 people) is on board and luggage is loaded in the trunk room
Point "Q5" = indicates a situation where only one driver is on board and luggage is loaded in the trunk room.
[0027]
The control lines g1 and g2 are both defined as linear expressions using linear approximation. The control line g1 is an approximate straight line for the points Q1 and Q5, and the control line g2 is a point Q1, a point Q2 and a point Q3. , Q4 are shown respectively.
[0028]
As shown in the drawing, each control line is defined as a straight line, and the slope of the control line g1 is expressed by a proportional expression “p = α1 · Δh” when the inclination is described as “α1 (<0)”. When the inclination of the control line g2 is described as “α2 (<0)”, this is expressed by a proportional expression “p = α2 · Δh + β” (the control line g1 is the control line in FIG. 2). Since the inclination is larger than g2, | α1 |> | α2 |, and an example of “β = 0” is shown.)
[0029]
As described above, when the correlation equation indicating the p-Δh characteristic is a first-order approximation equation and the control line is defined as a straight line passing through the origin, there is an advantage that the calculation process is simplified. When these two control lines are properly used, it is only necessary to provide a seating sensor for detecting whether or not a person is seated on the passenger seat as a load state detecting means. That is, it is known that there is no need to detect the presence or absence of a cargo in the trunk room because it is known that no person is seated in the passenger seat in the state shown by the points Q1 and Q5. This is because the line can be specified immediately (there is no need to discriminate between the points Q4 and Q5).
[0030]
Therefore, in this example, the control line g1 may be selected when the seating of the passenger on the passenger seat is not detected, and the control line g2 may be selected when the seating of the passenger on the passenger seat is detected. There is an advantage that the switching can be easily performed according to the presence or absence of the passenger seating.
[0031]
By the way, since the characteristics shown in FIG. 2 are not always guaranteed in all vehicles, the accuracy of the vehicle attitude detection caused by the variation in the mounting accuracy of the vehicle height sensor to the vehicle body is a problem. Become.
[0032]
FIG. 3 shows that the data is shifted in the horizontal axis (Δh axis) direction as shown at points Q1 ′ to Q5 ′ due to the offset caused by the mounting error of the vehicle height sensor or the like with respect to points Q1 to Q5 shown in FIG. It shows the state. In the figure, the control lines indicated by dotted lines indicate the above-mentioned g1 and g2, whereas the control lines g1 'and g2' indicated by the solid lines are located at positions offset on the p-axis downward in the figure. .
[0033]
That is, since the control line g1 'for the points Q1' and Q5 'is a straight line passing through two points, the p-intercept only passes through a position shifted from the origin, and there is no problem in the approximation accuracy. As can be seen from the figure, g2 'comes far away from the points Q2', Q3 ', and Q4', and the approximation accuracy due to this positional shift is a problem.
[0034]
Therefore, the following method can be cited as a countermeasure.
[0035]
(I) Method of performing origin calibration by initial setting when mounting a vehicle height sensor
(Ii) Method of storing output of vehicle height sensor at the time of initial aiming adjustment
(Iii) A method of approximating each control line with straight lines parallel to each other
[0036]
The above method (i) is a method of offsetting the mounting error of the vehicle height sensor by the initial adjustment (zero point adjustment) and calibrating the absolute value of the sensor output.
[0037]
In the method (ii), the output data of the vehicle height sensor at the time of the aiming adjustment is stored in the device, so that the mounting error of the vehicle height sensor and the variation of the vehicle posture are canceled to calibrate the absolute value of the sensor output. How to do it.
[0038]
However, these methods require initial adjustment and data storage in the memory, and are cumbersome to work, or have to be re-calibrated again during subsequent aiming adjustment, so if you want to avoid such inconveniences Method (iii) is preferred.
[0039]
FIG. 4 illustrates two parallel control lines G1 and G2, with the horizontal axis representing the vehicle height displacement “Δh” and the vertical axis representing the pitch angle “p”. The meanings of the points Q1 to Q5 are as described above.
[0040]
The control lines G1 and G2 are both defined as linear expressions by using linear approximation, but both have the same gradient (this is described as “α” (<0)) and are on the p-axis. Are different straight lines. That is, the control line G1 is an approximate straight line for the points Q1 and Q5 and is represented by “p = α · Δh”, while the control line G2 is an approximate straight line for the points Q2, Q3 and Q4, = Α · Δh + β ”. The control line G1 is selected when the seating of the passenger in the passenger seat is not detected, and the control line G2 is selected when the seating of the passenger in the passenger seat is detected.
[0041]
FIG. 5 shows a state in which the data is shifted in the horizontal axis (Δh axis) direction as shown at points Q1 ′ to Q5 ′ due to an offset caused by a mounting error of the vehicle height sensor or the like with respect to points Q1 to Q5. It is. In the figure, the control lines indicated by dotted lines indicate the above-mentioned G1 and G2, and the control lines G1 'and G2' indicated by solid lines respectively correspond to the positions shifted by a downward offset on the p-axis. Control line.
[0042]
As can be seen from the figure, for example, it is understood that there is no change in the relative positional relationship between the points Q1 and Q5 with respect to the control line G1 and the relative positional relationship between the points Q1 'and Q5' with respect to the control line G1 '. That is, the length of the perpendicular foot hanging from the point Q5 to the control line G1 (see "d5" in the figure) is the length of the perpendicular foot hanging from the point Q5 'to the control line G1' (see the figure). "D5 '").
[0043]
Similarly, it can be seen that there is no change in the relative positional relationship between the points Q2, Q3, Q4 with respect to the control line G2 and the relative positional relationship between the points Q2 ', Q3', Q4 'with respect to the control line G2'. For example, the length of a perpendicular foot hanging from the point Q2 to the control line G2 (see “d2” in the figure) and the length of a perpendicular foot hanging from the point Q2 ′ to the control line G2 ′ (see FIG. "D2 '") are equal, and the length of a perpendicular foot (see "d4" in the figure) hanging from the point Q4 to the control line G2 is equal to the length of the foot from the point Q4' to the control line G2 '. It can be easily confirmed from the fact that the lengths of the legs of the perpendicular line (see "d4 '" in the figure) are equal.
[0044]
As described above, in the method (iii), even if an offset occurs in each output value of the vehicle height sensor, the relationship that the control lines are parallel to each other is maintained, so that the relative position between each point and the control line is maintained. There is an advantage that the positional relationship is not adversely affected (that is, no displacement occurs), and since the control lines are parallel to each other, the switching of the p-intercept is performed according to the presence or absence of the passenger seating. The control line to be used can be selected simply by performing the operation.
[0045]
When the number of occupants in the front seat or the occupant weight is detected based on the detection signal from the load state detecting means 3, the control lines are switched in accordance with the load state at that time, for example, in the following three forms. .
[0046]
-A form in which the inclination of the control line is switched (one of the linear control lines passing through the origin is selected.)
A mode in which the intercept on the p-axis of the control line is switched (any one of linear control lines having the same inclination and different p-intercepts is selected)
A mode in which the inclination of the control line and the intercept on the p-axis are switched.
[0047]
In the examples shown in FIGS. 2 and 4, it is preferable that the inclination is switched from the viewpoint of the approximation accuracy of the control line, and from the viewpoint of the control accuracy due to the variation in the mounting accuracy of the vehicle height detecting means, p is used. It is preferable to switch the section on the axis (it is important to use each mode properly according to the purpose).
[0048]
Next, a specific configuration in the case of controlling the direction of the irradiation optical axis of the lamp with respect to the change in the vehicle pitch angle will be described.
[0049]
First, as a configuration in which the presence / absence of an occupant or the occupant's weight is detected by the load state detecting means 3 and the control line is switched, for example, the following embodiments are given.
[0050]
(I) A form in which the number of occupants in the front seat or the occupant weight is detected, and the control line is switched according to the load state at that time.
(II) A form in which the occupant weights of the driver's seat and the passenger's seat are separately detected, the load state is classified into a plurality of stages, and the control line is switched according to the load state of each stage.
(III) A form in which the total weight of the occupant in the front seat is detected, the load state is classified into a plurality of stages, and the control line is switched according to the load state in each stage.
[0051]
First, in the form (I), the load state of the front seat is grasped based on a detection signal from the load state detecting means, and the inclination or intercept of the control line is switched according to the grasp.
[0052]
For example, a configuration using the following sensor is adopted as the load state detecting means.
[0053]
-Passenger's seat sensor (a sensor that can detect a weight of 30 kg or more and is used in an airbag system, etc.)
A driver's seat sensor (for example, a sensor capable of detecting a weight of 60 kg or more; a sensor having a different threshold value in comparison with a passenger's seat sensor);
[0054]
By using these two sensors, for example, the following four states can be determined for the riding state of the front seat of the vehicle.
[0055]
(C1) One driver less than 60 kg, no passengers in the front passenger seat
(C2) Driver seat 60 kg or more, 1 person, no passenger in front passenger seat
(C3) One driver less than 60 kg, one passenger more than 30 kg
(C4) Driver's seat 60 kg or more and one passenger's seat 30 kg or more.
[0056]
The control line (first-order approximation straight line) may be switched according to the load state detected by each sensor. When the inclination of the control line is almost constant (that is, when the inclination of the first-order approximation expression hardly changes due to a change in the load state), it can be easily handled by switching the intercept of the control line.
[0057]
FIG. 6 is a graph illustrating the correlation between the change in the vehicle height of the rear wheels and the change in the pitch angle with respect to the change in the load on the front seat. The relationship between the two is schematically shown with the pitch angle "p" taken on the axis.
[0058]
In the figure, the meaning of each graph line indicated by gf1 to gf3 is as follows.
[0059]
"Gf1" = first-order approximate straight line when the front seat load is 30 kg
"Gf2" = first-order approximate straight line when the front seat load is 75 kg
"Gf3" = first-order approximate straight line when the front seat load is 120 kg
[0060]
Note that these three graph lines are based on data obtained when luggage is not put in the trunk room of the vehicle, and are all expressed by linear approximations by linear approximation.
[0061]
The graph lines gg1, gg2, and gg3 are based on data obtained when a heavy load of 100 kg is loaded in the trunk room of the vehicle, and the meaning of each graph line is as follows.
[0062]
-"Gg1" = first approximation straight line when the front seat load is 30 kg and the trunk load is 100 kg
"Gg2" = first-order approximate straight line when the front seat load is 75 kg and the trunk load is 100 kg
"Gg3" = first-order approximate straight line when the front seat load is 120 kg and the trunk load is 100 kg
[0063]
These graph lines can also be represented by linear approximations by linear approximation, however, the point common to the graph lines gf1 to gf3 and gg1 to gg3 is that the slopes are almost equal. That is, each graph line is represented by a linear expression “p = a · Δh + b” where a common slope is “a”, and only the intercept b (p intercept) differs for each graph line. Therefore, even if the load on the front seat or the trunk room changes, the inclination of the control line hardly changes. Therefore, an accurate approximate expression can be obtained only by switching the intercept b according to the load state.
[0064]
Therefore, for example, the front seat load can be classified into a plurality of stages as in the above (C1) to (C4) to divide the load state, and an appropriate control line can be selected according to each state.
[0065]
In the mode (II), the main point is that the load state detection means 3 detects the occupant weights of the driver's seat and the passenger's seat separately and classifies the load state into a plurality of stages.
[0066]
That is, in the form of detecting the occupant weight as a continuous amount, it is necessary to prepare innumerable control lines corresponding to the detected weight, or to define the slope or p-intercept of the control line as a function of the detected weight. In the embodiment, the weight applied to each seat is detected in a stepwise range. For example, after detecting the weight of each seat at intervals of 5 kg or 10 kg, a control line corresponding to each load state may be selected stepwise.
[0067]
Regarding the form (III), the weight applied to the driver's seat and the passenger's seat is not detected separately, and the load state is specified by a combination thereof. It is classified into. In other words, the control can be simplified because the total weight of the occupant in the front seat is divided into stages or divided into ranges and the control line corresponding to the load state at each stage is selected. The load state of the front seat of the vehicle is determined at a predetermined weight interval such as 5 kg or 10 kg from the minimum value.)
[0068]
Next, control when the load state detecting means 3 detects the presence or absence of a load or the weight of the load will be described.
[0069]
As shown in FIG. 6, even if the total occupant weight in the front seat of the vehicle is the same, the control lines differ depending on the weight of the cargo in the trunk room, but the slopes of the control lines hardly change, and the p-intercepts differ. ing. Therefore, when the presence or absence of the load applied to the trunk room or the bed of the vehicle or the weight of the load is detected, the intercept of the control line may be switched according to the load state at that time.
[0070]
FIG. 7 is a graph showing an example of the correlation between the change in the vehicle height of the rear wheel and the change in the pitch angle with respect to the change in the load of the trunk (luggage). The vertical axis represents the pitch angle "p", and schematically shows the relationship between the two.
[0071]
The meaning of each graph line is as follows.
[0072]
-"K0" = first approximation straight line when the load is 0 kg (no luggage)
-"K1" = first-order approximate straight line when the load is 30 kg
-"K2" = first-order approximate straight line when the load is 75 kg
-"K3" = first-order approximate straight line when the load is 100 kg
[0073]
It should be noted that the graph curve is located on the upper side of FIG. 7 as the load increases, but this is because the sinking of the rear wheel portion increases.
[0074]
As can be seen from the figure, each graph line can be represented by a first-order approximation formula, and is a straight line substantially parallel to each other, and the slopes of each line are almost equal. That is, each graph line is represented by a linear expression “p = a · Δh + b” when the inclination is “a”, and only the intercept b differs depending on the graph line. Therefore, even if the load applied to the trunk room changes, the inclination of the control line hardly changes, and an accurate approximate expression can be obtained only by switching the intercept b according to the load state.
[0075]
Note that this embodiment can be combined with the above embodiments (I) to (III). For example, a seating sensor capable of detecting the load of the front seat (driver's seat and passenger's seat) in stages and a load detecting sensor for the trunk room are additionally provided to detect the total load of the front seat and the load applied to the trunk. By switching the control line according to the detection result, more accurate irradiation direction control can be realized. In other words, more detailed load state detection becomes possible as the state progresses from detecting the presence / absence of a seat and the presence / absence of a load applied to the trunk room to detecting the weight at the time of sitting and the weight of the load stepwise.
[0076]
Regarding vehicle height data according to conditions such as occupant placement and weight, and the position and weight of cargo in the trunk room, it is clear if data on changes in vehicle attitude are changed by actually changing those loads. However, it can also be calculated from a calculation method relating to the vehicle attitude. In fact, in the development of an auto-leveling device, changes in vehicle attitude due to load conditions are calculated based on vehicle design data.
[0077]
The load applied to the vehicle is set to “M”, the position coordinates of the load point are written as (X, Y) (the traveling direction of the vehicle is set to the Y-axis direction, and the width direction of the vehicle is set to the X-axis direction). When the load applied to each of the front wheel and the rear wheel is described as “Fi” (i = 1 to 4), “M = ΣFi” (“Σ” means the sum of i) is established by the load distribution.
[0078]
Further, using the position data (xi, yi) of the left and right front wheels and the rear wheels, two relational expressions are obtained from the balance of the moment of force. That is, the sum of the components of the moment, Σ (X−xi) · Fi and Σ (Y−yi) · Fi, are both zero for the X axis and the Y axis.
[0079]
When the difference between the left and right vehicle height changes related to the front wheels is "L1-L2" and the difference between the right and left vehicle height changes related to the rear wheels is "L3-L4", they are assumed to be equal (L1-L2 = L3). -L4). This takes into account that the support portion of each wheel is on a single plane, and the difference between the left and right vehicle height of the front wheel portion and the difference of the left and right vehicle height of the rear wheel portion are the same (that is, The plane connecting the four points does not twist with respect to the change in vehicle height of each wheel from the reference position.)
[0080]
Further, when the spring constants of the front wheel portion and the rear wheel portion corresponding to the elastic modulus of the suspension are denoted by “Kf” and “Kr”, respectively, “Fi = Kf · Li” (i = 1, 2), “Fi” = Kr · Li ”(i = 3,4).
[0081]
The position data “(xi, yi)” (i = 1 to 4) of each wheel can be known from the tread width of the front wheels and the rear wheels and the wheel base.
[0082]
Therefore, Li (i = 1 to 4) can be solved by simultaneous equations.
[0083]
If the position information is given as the load M as the weight of the occupant or the load, the change in vehicle height at that time can be accurately calculated.
[0084]
Note that a plurality of loads may be calculated for each load, and the sum of the results may be obtained.
[0085]
【Example】
8 to 11 show an embodiment in which the present invention is applied to an irradiation control device (auto-leveling device) for a vehicle lamp.
[0086]
FIG. 8 shows a main part of the device configuration example 8, and includes the following elements (numbers in parentheses indicate symbols).
[0087]
・ Rear height sensor (9)
・ Seat sensor (10)
・ Load sensor (11)
・ Vehicle speed sensor (12)
・ ECU (13)
.Drive source (14) and leveling mechanism (15)
・ Head lamp (16)
[0088]
The ECU 13 is an abbreviation of an electronic control unit, and includes a signal conversion unit 13a, a vehicle attitude calculation unit 13b, an arithmetic processing unit 13c, and a drive control unit 13d, as illustrated. The actual control is realized by software processing using a microcomputer. Although not shown, various signals such as an instruction signal from a headlamp switch and an ignition signal as an engine start signal are input to the ECU 13.
[0089]
The left and right headlamps attached to the front of the vehicle include a drive source 14 such as a motor and a leveling mechanism 15. For example, a mechanism that uses a stepping motor as a drive source is attached to the back of the lamp body of the headlamp 16, and illuminates the headlamp by tilting a reflecting mirror in the lamp room on a vertical plane including its optical axis. The optical axis is controlled so as to face a desired direction. In the following, only one headlamp will be described because of the simplification of the description and the fact that there is no difference in leveling control between the two headlamps. Of course, a mode in which the irradiation optical axis directions of the lamps are individually controlled is also possible.)
[0090]
The vehicle height sensor 9 is provided on, for example, a rear suspension, and a detection signal corresponding to the vehicle height displacement is sent to the ECU 13. A sensor or the like provided for an electronically controlled air suspension for the rear wheels is used.
[0091]
The seating sensor 10 is provided to detect whether or not a person is sitting in a passenger seat or a driver's seat, and an output signal thereof is sent to the ECU 13. For example, the presence / absence of a weight of 15 kg or more in the passenger seat can be detected by a seating sensor. A sensor provided in a passenger seat as an existing facility (a sensor provided for detecting a weight of a passenger so that an airbag is not activated when a child is seated in an airbag system, etc.). No. Further, the presence of the occupant can be detected using the buckle sensor of the seat belt.
[0092]
The load sensor 11 is provided to detect a load in the trunk room, and a detection signal is sent to the ECU 13.
[0093]
The vehicle speed sensor 12 provides information for detecting the vehicle speed and determining whether the vehicle is stopped or running. The detection signal is sent to the ECU 13. Note that, as the vehicle speed sensor, for example, a sensor provided on the rear wheel for an ABS (Anti-skid Break System) can be used, and a detection signal from the sensor is sent from the ABS control unit to the ECU 13.
[0094]
The signal conversion unit 13a converts the output voltage of the vehicle height sensor 9 into vehicle height value data, and the result is sent to the vehicle posture calculation unit 13b at the subsequent stage.
[0095]
The vehicle attitude calculator 13b calculates a vehicle pitch angle corresponding to a change in the vehicle height value according to a predetermined control line. Here, the predetermined control lines are control lines indicating the above-mentioned p-Δh characteristic, and these are processed as a first-order approximate expression. Detection signals from the seating sensor 10 and the load sensor 11 are sent to the vehicle attitude calculator 13b, and a control line to be used is determined according to the load state determination result based on the signals. Is specified.
[0096]
The arithmetic processing unit 13c receives the information indicating the vehicle posture from the vehicle posture calculation unit 13b, calculates a control amount for driving the leveling mechanism 15, and sends it to the drive control unit 13d. At this time, since the signal from the vehicle speed sensor 12 is sent to the arithmetic processing unit 13c, the ECU 13 can know whether the vehicle is currently stopped or running. Therefore, for example, it is possible to perform control such that the leveling control is performed when the vehicle is stopped or the vehicle is traveling stably, and the leveling control is prohibited in other situations (for example, a rough road having a lot of unevenness). In addition, as for the method of determining whether or not "stable driving", for example, a method of determining from the vehicle speed and acceleration during vehicle running, furthermore, a method of determining from the jerk, a method of determining from the aspect of the vehicle height change, and the like. Various forms are known.
[0097]
The drive control unit 13d sends a control signal corresponding to the control amount from the arithmetic processing unit 13c to the drive source 14 (stepping motor or the like) to operate the leveling mechanism 15. As a result, control is performed such that the angle of the headlamp 16 with respect to the irradiation optical axis or the visual recognition distance in front of the lamp becomes constant in accordance with the change in the vehicle attitude.
[0098]
FIG. 9 schematically shows the arrangement of the above elements in a vehicle.
[0099]
A link type sensor is used as the vehicle height sensor 9 and is provided on the axle portion of the rear wheel, and a carbon contact type sensor is used as the seating sensor 10 attached to the passenger seat or the like. Can be The vehicle speed sensor 12 is provided on the rear wheel for ABS.
[0100]
The output signal of each sensor is sent to the ECU 13. For example, the output signal of the ECU is sent to a motor, and the rotation force of the sensor serves as the power of the leveling mechanism 15 in the headlamp 16.
[0101]
FIGS. 10 and 11 are flowcharts showing an example of the flow of main processing in the ECU.
[0102]
First, in step S1 in FIG. 10, after processing such as initialization of an input / output port and a memory is performed on the microcomputer in the ECU, the initial setting of the control reference position (that is, the origin position of the actuator, etc.) is finished. After that, the timer interrupt is permitted in the next step S2, and then the process proceeds to step S3.
[0103]
In step S3, data from the vehicle height sensor 9 is obtained.
[0104]
Then, in the next step S4, the load distribution of the front seat is detected. For example, the seating sensor 10 detects whether or not a person is seated in the front passenger seat. As a result, if only one driver (driver) is detected in the front seat, the process proceeds to step S5, and two passengers (front driver) are detected. If a driver and a passenger on the passenger seat are detected, the process proceeds to step S6.
[0105]
In step S5, a control line to be used is selected according to the weight assumed in the case of one front seat or the detected weight of the driver. In step S6, a control line to be used is selected in accordance with the estimated weight of the two front seats or the detected value of the total weight of the front seat occupants. In the case of measuring the weight of luggage in the trunk room, an appropriate control line is determined with reference to the detection result of the load sensor 11.
[0106]
In step S7 following steps S5 and S6, the vehicle pitch angle with respect to the vehicle height displacement is calculated according to the selected control line.
[0107]
In the next step S8, after detecting the detection data from the vehicle speed sensor by the interruption process, the process proceeds to step S9 in FIG. 11 to calculate the vehicle speed.
[0108]
Then, in the next step S10, the acceleration is calculated from the time rate of change of the vehicle speed.
[0109]
In the next step S11, the response to the pitch angle obtained in the previous step S7 is defined according to the vehicle running state (vehicle speed and acceleration). That is, leveling control is performed on the pitch angle data that reflects the data as it is (control by real-time processing), or a value (moving average value, etc.) after filtering processing based on the data is obtained, and leveling control corresponding to the value is performed. Decide what to do.
[0110]
For example, in the case where the control category according to the traveling speed and the traveling acceleration is adopted, if the traveling speed falls below the lower threshold, a pitch angle average value in a predetermined time (for example, 0.5 seconds) is used; If the traveling speed is equal to or higher than the lower threshold value, the magnitude of the acceleration is determined. When the magnitude of the acceleration exceeds the upper threshold, the pitch angle obtained in step S7 is used as it is to perform the real-time processing. When the magnitude of the acceleration exceeds the lower limit threshold, the average pitch angle value for a predetermined time (for example, 0.5 seconds) is used. A pitch angle average value (for example, 5 seconds) is used.
[0111]
The real-time processing or the averaging processing by filtering is designed in consideration of the following items.
[0112]
-If the acceleration is large, it is better to shorten the time required for the averaging process as much as possible to make the control response faster.
[0113]
When the vehicle is stopped, it is preferable that the irradiation direction control follows the change of the vehicle attitude without time delay.
[0114]
When the acceleration is small (for example, when traveling on a rough road with a lot of unevenness), the control response is delayed so that the control of the irradiation optical axis direction is not over-corrected, and the optical axis direction is changed in a dark state. It is preferable not to change.
[0115]
When the change in acceleration is remarkable such as sudden acceleration (when the jerk is large), transition to the moving average processing after real-time processing can follow the change in the vehicle attitude without time delay.
[0116]
In the next step S12, the ECU 13 calculates a control amount related to the irradiation optical axis direction control according to the pitch angle determined in the previous step, and then proceeds to step S13 to determine whether or not an instruction to turn on the headlamp 6 is issued. Judge. That is, if the headlamp switch has issued an instruction to turn on the headlamp, the process proceeds to the next step S14, but if not, the process returns to step S3 in FIG.
[0117]
In step S14, a control signal from the ECU 13 is sent to a motor drive circuit and the like constituting the leveling mechanism 15, and the irradiation direction of the headlamp 16 is controlled. Then, the process returns to step S3 in FIG.
[0118]
【The invention's effect】
As is apparent from the above description, according to the first aspect of the present invention, the load state of the occupant or the load in the vehicle is grasped by the load state detecting means, and the posture of the vehicle is determined based on the detection signal of the vehicle height detecting means. Control in the direction of the irradiation optical axis can be performed with high accuracy. Moreover, for this purpose, it is not necessary to provide vehicle height detecting means on the axles of the front wheels and the rear wheels of the vehicle. Then, since it is only necessary to selectively switch a control line prepared in advance or a slope related to the control line or a slice on the p-axis with respect to the load state, control and configuration are not complicated.
[0119]
According to the invention according to claim 2, by detecting the presence or absence or the weight of the occupant, the irradiation direction of the lamp can be accurately controlled.
[0120]
According to the third aspect of the invention, by detecting the presence or absence of a load or the weight of the load, the irradiation direction of the lamp can be accurately controlled.
[0121]
According to the invention of claim 4, the control accuracy can be enhanced by dividing the load state according to the occupant weight of the driver's seat and the passenger's seat into a plurality of stages.
[0122]
According to the invention of claim 5, the control accuracy can be enhanced by dividing the load state according to the total weight of the occupant in the front seat into a plurality of stages.
[0123]
According to the invention of claim 6, control accuracy can be improved by using a control line according to the presence or absence of a load and the weight.
[0124]
According to the invention according to claims 5 and 6, by switching the intercept of the control line according to the load state, it is possible to easily cope with a difference in the load condition.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a basic configuration example of an irradiation direction control device for a vehicle lamp according to the present invention.
FIG. 2 is a graph illustrating a relationship between a vehicle height displacement and a vehicle posture.
FIG. 3 is a graph for explaining the effect of a mounting error of a vehicle height sensor.
FIG. 4 is a graph for explaining an approximation method in which control lines are set to straight lines parallel to each other;
FIG. 5 is a graph for explaining the influence of a mounting error of a vehicle height sensor in the method of FIG. 4;
FIG. 6 is a graph illustrating the relationship between a change in vehicle height of a rear wheel and a pitch angle with respect to a change in load on a front seat of a vehicle.
FIG. 7 is a graph illustrating a relationship between a change in vehicle height of a rear wheel and a pitch angle with respect to a change in load on a trunk.
FIG. 8 shows an embodiment of the present invention together with FIG. 9 to FIG. 11, and FIG. 8 is a block diagram showing an apparatus configuration.
FIG. 9 is a diagram schematically showing an arrangement of sensors and the like in a vehicle.
FIG. 10 is a flowchart illustrating an example of a process together with FIG. 11, and FIG. 10 is a diagram illustrating a first half of the process.
FIG. 11 is a diagram illustrating the latter half of the process.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 irradiation direction control device 2 vehicle height detection means 3 load state detection means 5 irradiation control means 6 driving means 7 vehicle lighting

Claims (6)

In an irradiation direction control device for a vehicle lamp for changing the irradiation direction of the lamp in accordance with the inclination of the vehicle posture in the traveling direction of the vehicle,
Vehicle height detecting means for detecting a vehicle height displacement related to an axle portion of a front wheel or a rear wheel of the vehicle,
Driving means for changing the direction of the irradiation optical axis of the lamp,
Load state detection means for detecting a change in the load state of the vehicle due to a change in the occupant or the load,
Irradiation control means for transmitting a correction signal related to the irradiation direction of the lamp to the driving means in accordance with signals from the vehicle height detection means and the load state detection means,
When the vehicle height displacement detected by the vehicle height detecting means is set to “Δh” and the pitch angle of the vehicle with respect to the vehicle height displacement is set to “p”, the irradiation control means sets the correlation between the two as p−Δh A plurality of control lines each having a characteristic represented by a primary expression are prepared in advance for each load state of the vehicle, and a control line corresponding to the current load state or a control line corresponding to the control line based on a signal from the load state detection unit is provided. An irradiation direction control device for a vehicular lamp, wherein an irradiation control unit calculates a pitch angle from a vehicle height displacement in accordance with the control line while switching a slope or a slice on a p-axis. The irradiation direction control device for a vehicle lamp according to claim 1,
An irradiation direction control device for a vehicle lamp, wherein the presence or absence or weight of an occupant is detected by the load state detection means. The irradiation direction control device for a vehicle lamp according to claim 1,
An irradiation direction control device for a vehicle lamp, wherein the presence or absence of a load or the weight of the load is detected by the load state detecting means. The irradiation direction control device for a vehicle lamp according to claim 2,
The occupant weights of the driver's seat and the passenger's seat are individually detected based on the detection signal by the load state detecting means, and the load state is classified into a plurality of stages, and the control line is switched according to the load state of each stage. Direction control device for vehicle lighting. The irradiation direction control device for a vehicle lamp according to claim 2,
A vehicular lamp characterized by detecting the total weight of the occupant in the front seat based on a detection signal from the load state detecting means, classifying the load state into a plurality of stages, and switching a control line according to the load state at each stage. Irradiation direction control device. The irradiation direction control device for a vehicle lamp according to claim 3,
An irradiation direction control device for a vehicular lamp, wherein the load state detecting means detects the presence or absence of a load applied to a trunk room or a cargo bed of a vehicle or the weight of the load, and switches an intercept of a control line according to the load state.

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