CN102029941B - Headlamp adaptive control method and device - Google Patents

Abstract

The invention discloses an adaptive control method and device for automobile headlights. The method includes: 1) acquiring the current speed v of the automobile in real time, and obtaining the safe braking distance S of the automobile at the current speed; 2) obtaining the maximum speed of the headlight. 3) obtain the vertical deflection angle β corresponding to the best lighting position of the headlight; 4) output control signals to control the rotation of the headlight in real time; the device includes a control unit (1) and a control unit (1) respectively The detection unit (2) and the drive mechanism (3) connected to the unit (1), the detection unit (2) includes a speed sensor (21), a steering wheel angle sensor (22), a front wheel vehicle height sensor (23), a rear wheel vehicle height sensor Sensor (24), sunlight and rain sensor (25) and acceleration sensor (26). The invention has the advantages of large irradiation range, good lighting effect, difficult reflection glare, simple structure, precise control, good environmental adaptability, safety and reliability, and comfortable driving.

Description

Automobile headlight adaptive control method and device

technical field

The invention relates to the field of automobiles, in particular to an adaptive control method and device for automobile headlights.

Background technique

The irradiation direction of traditional car headlights is parallel to the body and cannot be deflected with the adjustment of the direction of the vehicle. Therefore, in practical applications, there are often many problems, such as: the effectiveness of lighting in urban areas with complex traffic conditions at night will be reduced, especially when there are dark areas of lighting when turning; the front and rear loads of the vehicle change, or start And when accelerating and braking while driving, the headlights will move along with the vehicle body, resulting in a reduction in the irradiation range; when the vehicle is driving in rainy days, the water on the ground reflects the light of the headlights, which is prone to reflective glare. It seriously affects the driver's judgment on the road ahead, resulting in a reduction in the safety performance and driving comfort of the car.

Contents of the invention

The technical problem to be solved by the present invention is to provide a self-adaptive automobile headlight with large irradiation range, good lighting effect, not easy to produce reflected glare, simple and efficient structure, precise control, good environmental adaptability, safety and reliability, and comfortable driving. Control method and device.

In order to solve the above-mentioned technical problems, the technical solution adopted in the present invention is: a kind of automobile headlamp self-adaptive control method, and its implementation steps are as follows:

1) Get the current speed v of the car in real time, and get the safe braking distance S of the car at the current speed;

并根据式（101）2) Obtain the steering wheel angle of the car in real time

And according to formula (101)

式（101）

Formula (101)

的比例系数，D为汽车前后轮轮轴之间的距离；Obtain the horizontal deflection angle ω corresponding to the current optimal lighting position of the headlight, where k is the steering angle of the front wheel and the steering wheel angle

The proportional coefficient of D is the distance between the front and rear wheel axles of the car;

3) Obtain the change amount ΔH ₁ of the front wheel body height and the change amount ΔH ₀ of the rear wheel body height in real time, and according to formula (102)

$\mathrm{\&beta;}={\mathrm{the\; tan}}^{-1}\frac{\mathrm{\&Delta;}{h}_0-\mathrm{\&Delta;}{\mathrm{<figure-callout\; id="1"\; label="h"\; filenames="HDA0000038974430000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_1}{\mathrm{D.}}+{\mathrm{the\; tan}}^{-1}\frac{\frac{L-\mathrm{D.}}{\mathrm{D.}}(\mathrm{\&Delta;}{h}_0-\mathrm{\&Delta;}{h}_1)+h}{\mathrm{D.}}-{\mathrm{the\; tan}}^{-1}\frac{h}{C}$ Formula (102)

The vertical deflection angle β corresponding to the current optimal lighting position of the headlight is obtained, where L is the horizontal distance between the headlight and the rear wheel axle, C is the lighting distance when the headlight is horizontal, and H is the distance of the light axis of the headlight height above the ground;

4) Output the control signal according to the above-mentioned horizontal deflection angle ω and vertical deflection angle β to control the rotation of the headlight in real time.

As a further improvement of the adaptive control method for automobile headlights of the present invention:

In the step 1), the preset fitting parameter data table is obtained before the safe braking distance S. When obtaining the safe braking distance S, the current rainfall, light intensity, vehicle front and rear tilt state and road flatness are obtained first, and then according to Find the fitting parameter data table for the above information to obtain the turning distance fitting parameters K ₁ , K ₂ , and K ₃ , and obtain the current speed v and S=K ₁ v ² +K ₂ v+K ₃ according to the current speed v obtained in the above step 1) Safe braking distance S.

The detailed steps of obtaining the fitting parameters K ₁ , K ₂ , and K ₃ of the turning distance are as follows:

① Make a decision on the amount of rainfall and determine whether it is sunny, light rain or heavy rain;

② Make a decision on the light intensity, and determine whether it belongs to strong light, dim light or night;

③Decision-making on the forward and backward tilt state of the car, and determine whether it is forward tilt, normal or backward tilt;

④ Make a decision on the flatness of the road, and determine whether it is flat, normal or uneven;

⑤ Make a decision on the driving speed of the car, and determine whether it belongs to high speed, normal or low speed;

⑥ According to the decision results of ①～⑤ above, query the fitting parameter data table to obtain the turning distance fitting parameters K ₁ , K ₂ , and K ₃ .

The step 1) before obtaining the current speed v of the car includes the step of detecting the rotation of the headlights of the car. If the rotation of the headlights fails, reset the position of the headlights and stop the adaptation to the headlights control.

The control signal output in step 4) is a gradually changing control signal.

The control signal is a PWM signal, and the gradual change control signal means that the relationship between the control signal and the initial control signal is (PP ₀ )=nt, where P is the duty ratio parameter of the current output PWM signal, and P ₀ is The duty ratio parameter of the initial PWM signal, n is the variation of each adjustment, and t is the adjustment time, and the value of t is related to the road flatness decision result obtained in the step 4 and the vehicle speed obtained in the step 5 The decision result is related. When the car is driving at high speed and the road is uneven, the value of t is infinite, and the PWM signal remains unchanged; when the car is driving at high speed and the road is normal, the value of t is 0.75s; when the car is driving at high speed and the road is flat, the value of t is 0.5 s; when the car is driving normally and the road is uneven, the value of t is 1.5s; when the car is driving normally and the road is normal, the value of t is 1s; When the vehicle is flat, the value of t is 2s; when the car is running at a low speed and the road is normal, the value of t is 1.5s; when the car is driving at a low speed and the road is flat, the value of t is 1.25s.

前轮车身高度变化量ΔH₁以及后轮车身高度变化量ΔH₀并输出至控制单元，所述控制单元获取汽车在当前速度v下的安全制动距离S，并根据所述检测单元的输出信息以及安全制动距离S获取前照灯当前最佳照明位置对应的水平偏转角ω、垂直偏转角β，并将所述水平偏转角ω和垂直偏转角β转换为对前照灯的转动控制信号并输出至驱动机构实时控制前照灯转动。The present invention also provides an adaptive control device for automobile headlights, which includes a control unit, a detection unit and a driving mechanism respectively connected to the control unit, and the detection unit obtains the current speed v and steering wheel angle of the vehicle in real time

The front wheel body height change ΔH ₁ and the rear wheel body height change ΔH ₀ are output to the control unit. The control unit obtains the safe braking distance S of the car at the current speed v, and according to the output information of the detection unit And the safe braking distance S obtains the horizontal deflection angle ω and the vertical deflection angle β corresponding to the current optimal lighting position of the headlight, and converts the horizontal deflection angle ω and the vertical deflection angle β into a rotation control signal for the headlight And output to the driving mechanism to control the rotation of the headlight in real time.

As a further improvement of the adaptive control device for automobile headlights of the present invention: the control unit according to formula (101)

式（101）

Formula (101)

Obtain the horizontal deflection angle ω corresponding to the current best lighting position of the headlight, according to formula (102)

$\mathrm{\&beta;}={\mathrm{the\; tan}}^{-1}\frac{\mathrm{\&Delta;}{h}_0-\mathrm{\&Delta;}{\mathrm{<figure-callout\; id="1"\; label="h"\; filenames="HDA0000038974430000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_1}{\mathrm{D.}}+{\mathrm{the\; tan}}^{-1}\frac{\frac{L-\mathrm{D.}}{\mathrm{D.}}(\mathrm{\&Delta;}{h}_0-\mathrm{\&Delta;}{h}_1)+h}{\mathrm{D.}}-{\mathrm{the\; tan}}^{-1}\frac{h}{C}$ Formula (102)

的比例系数，D为汽车前后轮轮轴之间的距离，L为前照灯与后轮轮轴的水平距离，C为前照灯水平时的照明距离、H为前照灯灯光光轴的离地高度。Get the vertical deflection angle β corresponding to the current optimal lighting position of the headlight, where v is the current speed of the car, and k is the front wheel steering angle and steering wheel angle

D is the distance between the front and rear wheel axles of the car, L is the horizontal distance between the headlight and the rear wheel axle, C is the illumination distance when the headlight is horizontal, and H is the ground clearance of the light axis of the headlight high.

的方向盘转角传感器、用于获取汽车的前轮车身高度变化量ΔH₁的前轮车身高度传感器、用于获取汽车的后轮车身高度变化量ΔH₀的后轮车身高度传感器、用于获取环境的雨量和光线强度的阳光雨量传感器和用于获取汽车加速度的加速度传感器，所述信号调理单元将阳光雨量传感器输出的雨量判定为晴天、小雨或者大雨，将阳光雨量传感器输出的光线强度判定为强光、微光或者黑夜，根据前轮车身高度传感器、后轮车身高度传感器输出的高度信息判定汽车前后倾斜状态为前倾、正常或者后倾，根据加速度传感器输出的加速度信息判定路面平坦度为平坦、正常或者不平坦，将速度传感器输出的汽车行驶速度判定为高速、正常或者低速，所述控制决策单元根据信号调理单元的决策结果从所述拟合参数数据表中查找拐弯距离拟合参数K₁、K₂、K₃，所述输出运算单元获得安全制动距离S，并根据所述检测单元输出的检测数据和所述安全制动距离S输出前照灯当前最佳照明位置对应的水平偏转角ω和垂直偏转角β，所述执行单元将所述水平偏转角ω和垂直偏转角β转换为对前照灯的控制信号并输出至驱动机构。The control unit includes a fitting parameter data table and a sequentially connected signal conditioning unit, a control decision-making unit, an output operation unit and an execution unit, the fitting parameter data table is connected to the control decision-making unit, and the detection unit includes a function for obtaining The speed sensor of the car's current speed v, used to obtain the steering wheel angle of the car

The steering wheel angle sensor, the front wheel body height sensor used to obtain the vehicle body height change of the front wheel ΔH ₁ , the rear wheel body height sensor used to obtain the rear wheel body height change ΔH ₀ of the car, the environment The sunlight and rain sensor of rainfall and light intensity and the acceleration sensor used to obtain the acceleration of the car, the signal conditioning unit determines the rainfall output by the sunlight and rain sensor as sunny, light rain or heavy rain, and determines the light intensity output by the sunlight and rain sensor as strong light , twilight or dark night, according to the height information output by the front wheel vehicle height sensor and rear wheel vehicle height sensor, it can be judged whether the front and rear tilt state of the car is forward, normal or backward, and the road surface flatness can be determined according to the acceleration information output by the acceleration sensor. Normal or uneven, determine the vehicle speed output by the speed sensor as high speed, normal or low speed, and the control decision-making unit searches the curve distance fitting parameter _K from the fitting parameter data table according to the decision result of the signal conditioning unit , K ₂ , K ₃ , the output calculation unit obtains the safe braking distance S, and outputs the horizontal deflection corresponding to the current optimal lighting position of the headlight according to the detection data output by the detection unit and the safe braking distance S Angle ω and vertical deflection angle β, the execution unit converts the horizontal deflection angle ω and vertical deflection angle β into control signals for the headlights and outputs them to the drive mechanism.

The drive mechanism includes a horizontal drive unit and a vertical drive unit. The horizontal drive unit includes a horizontal adjustment steering gear for driving the headlamp to rotate in the horizontal direction. The input end of the horizontal adjustment steering gear is connected to the control unit. The vertical drive unit includes a vertical adjustment steering gear for driving the headlight to rotate in the vertical direction, the input end of the vertical adjustment steering gear is connected to the control unit, the horizontal drive unit includes a horizontal cut-off point detection circuit, and the horizontal The cut-off point detection circuit outputs a detection signal to the control unit when the headlight rotates to the maximum angle position in the horizontal direction; the vertical drive unit includes a vertical cut-off point detection circuit, and the vertical cut-off point detection circuit when the headlight rotates to the vertical direction Output a detection signal to the control unit at the maximum rotation angle position.

The present invention has the following advantages:

1. The self-adaptive control method for automobile headlights of the present invention obtains the safe braking distance first, and then calculates the rotation angle of the headlights that should be driven according to formula (101) and formula (102), and automatically bends inward to one side when turning It can be adjusted to increase the viewing distance of the curve. When the front and rear loads of the vehicle change, the longitudinal angle of the headlight can be automatically adjusted to ensure the largest viewing range. It has the advantages of simple and efficient structure, precise control, good environmental adaptability, safety and reliability, and comfortable driving.

2. The present invention performs strategy matching according to the detection information to find the preset turning distance fitting parameters K ₁ , K ₂ , and K ₃ , and obtains the safe braking distance S through the turning distance fitting parameters K ₁ , K ₂ , and K ₃ , which can The processing is effectively simplified, the processing efficiency of the processor is improved, and the performance requirements of the hardware are lower.

3. The present invention searches for the curve fitting parameters K ₁ , K ₂ , and K ₃ by performing strategy matching according to rainfall, light intensity, vehicle front and rear inclination, road flatness, and vehicle speed in sequence, which can effectively simplify the data processing model, and In the decision-making sequence, since the change of rainfall and light intensity information is a gradual process, and the change of speed and road surface flatness is real-time, it is beneficial to increase the decision-making efficiency to make decisions on the sun and rainfall first. When driving in rainy days, the longitudinal angle of the headlights will be raised, so that it is not easy to reflect light due to ground water, which can prevent ground water from reflecting glare. In urban areas with complicated traffic conditions at night, the illumination distance is longer, and the lights are more concentrated and brighter. stronger.

4. The present invention uses an error detection mechanism. Once an initialization error occurs in the headlight control system, the rotation of the headlight fails, or the reading of sensor data fails during operation, the position of the headlight is reset and the headlight is stopped. The adaptive control of lights can effectively prevent accidents in the adaptive control of headlights, and has good safety and effectiveness.

5. The control signal output in step 4) of the present invention is a gradual control signal, so the output signal of each adjacent two cycles changes gradually, and no signal mutation occurs, thereby improving the continuity of the headlight lighting. Stability, safety and effectiveness can reduce the wear and noise caused by the sudden acceleration of the steering gear, and at the same time avoid the risk of loss of control caused by sudden angle adjustments.

6. The control signal of the present invention is a PWM signal, and the adjustment time of the PWM signal is related to the road flatness decision result obtained in step ④ and the vehicle speed decision result obtained in step ⑤, so the change period of the PWM signal can be adjusted according to different road conditions , so that the intelligent program and adaptability of the headlight control can be improved, making it safer and more reliable.

The auto headlight adaptive control device of the present invention has hardware devices corresponding to the above-mentioned adaptive control method of headlights, so it also has the advantages corresponding to the above method.

Description of drawings

Fig. 1 is the implementation flow schematic diagram of the method embodiment of the present invention;

Fig. 2 is the schematic diagram of the mathematical model of the horizontal corner situation of the embodiment of the present invention;

Fig. 3 is the schematic diagram of the mathematical model of the vertical adjustment situation of the embodiment of the present invention;

Fig. 4 is a schematic flowchart of strategy matching search for preset turning distance fitting parameters according to the method embodiment of the present invention;

Fig. 5 is the structural representation of the device embodiment of the present invention;

Fig. 6 is a schematic structural diagram of a control unit in an embodiment of the device of the present invention;

Fig. 7 is a schematic diagram of the processing flow of the control unit in the device embodiment of the present invention;

Fig. 8 is a top view structural schematic diagram of the driving mechanism in the device embodiment of the present invention;

Fig. 9 is a rear view structural schematic diagram of the driving mechanism in the device embodiment of the present invention;

Fig. 10 is a schematic diagram of the circuit principle of the cut-off point detection circuit in the device embodiment of the present invention.

Legend: 1. Control unit; 11. Signal conditioning unit; 12. Control decision-making unit; 13. Output calculation unit; 14. Execution unit; 15. Fitting parameter data table; 2. Detection unit; 21. Speed sensor; 22 , steering wheel angle sensor; 23, front wheel vehicle height sensor; 24, rear wheel vehicle height sensor; 25, sunlight and rain sensor; 26, acceleration sensor; 3, driving mechanism; 31, horizontal drive unit; 310, horizontal adjustment steering gear; 311. Horizontal cutoff point detection circuit; 32. Vertical drive unit; 320. Vertical adjustment servo; 321. Vertical cutoff point detection circuit; 4. Headlight; 41. Contact.

Detailed ways

As shown in Figure 1, the implementation steps of the adaptive control method for automobile headlights in the embodiment of the present invention are as follows:

1) Obtain the current speed v of the car in real time, and obtain the safe braking distance S of the car at the current speed v;

并根据式（101）2) Obtain the steering wheel angle of the car in real time

And according to formula (101)

式（101）

Formula (101)

Obtain the horizontal deflection angle ω corresponding to the current optimal lighting position of the headlight, where k is the steering angle of the front wheel and the steering wheel angle The proportional coefficient of D is the distance between the front and rear wheel axles of the car;

3) Obtain the change amount ΔH ₁ of the front wheel body height and the change amount ΔH ₀ of the rear wheel body height in real time, and according to formula (102)

$\mathrm{\&beta;}={\mathrm{the\; tan}}^{-1}\frac{\mathrm{\&Delta;}{h}_0-\mathrm{\&Delta;}{\mathrm{<figure-callout\; id="1"\; label="h"\; filenames="HDA0000038974430000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_1}{\mathrm{D.}}+{\mathrm{the\; tan}}^{-1}\frac{\frac{L-\mathrm{D.}}{\mathrm{D.}}(\mathrm{\&Delta;}{h}_0-\mathrm{\&Delta;}{h}_1)+h}{\mathrm{D.}}-{\mathrm{the\; tan}}^{-1}\frac{h}{C}$ Formula (102)

The vertical deflection angle β corresponding to the current optimal lighting position of the headlight is obtained, where L is the horizontal distance between the headlight and the rear wheel axle, C is the lighting distance when the headlight is horizontal, and H is the distance of the light axis of the headlight height above the ground;

4) Output the control signal according to the above-mentioned horizontal deflection angle ω and vertical deflection angle β to control the rotation of the headlight in real time.

根据阿克曼转向几何原理：sinδ=D/R对安全制动距离S采用拟合方法进行预估，则有S=2Rsinω，由此可以推导得出式（101）。汽车的方向盘转角

与前轮转向角之间呈线性关系，k即为前轮转向角与方向盘转角

的比例系数，车型不同，比例系数k的具体取值也会有所不同。As shown in Figure 2, δ is the steering angle of the outer front wheel, so we know

According to Ackermann's steering geometry principle: sinδ=D/R, the safe braking distance S is estimated by fitting method, then S=2Rsinω, from which the formula (101) can be derived. car steering wheel angle

There is a linear relationship between it and the front wheel steering angle, k is the front wheel steering angle and the steering wheel angle

The specific value of the proportional coefficient k will be different for different models.

As shown in Figure 3, the fore and aft inclination angle of the vehicle body is α, and ρ is the illumination angle when the headlight 4 is horizontal, then there is

therefore $\mathrm{\&alpha;}={\mathrm{the\; tan}}^{-1}\frac{\mathrm{\&Delta;}{h}_0-\mathrm{\&Delta;}{\mathrm{<figure-callout\; id="1"\; label="h"\; filenames="HDA0000038974430000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_1}{\mathrm{D.}},$ And according to

$\mathrm{<span\; class="notranslate">\; \&rho;</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; the\; tan</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}\frac{\mathrm{<span\; class="notranslate">\; \&Delta;H</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; h</span>}}{\mathrm{<span\; class="notranslate">\; D.</span>}}{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; the\; tan</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}\frac{\mathrm{<span\; class="notranslate">\; h</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}<span\; class="notranslate">\; ,</span>$

$\mathrm{<span\; class="notranslate">\; \&Delta;H</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; L</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; D.</span>}}{\mathrm{<span\; class="notranslate">\; D.</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&Delta;</span>}{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; \&Delta;</span>}{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>$

β=α+ρ

Where ΔH is the change in height of the optical axis of the light, from which formula (102) can be derived.

The safe braking distance S can theoretically be estimated by combining the average friction coefficient of the road surface with the current speed v of the vehicle. In order to improve the estimation accuracy of the safe braking distance S, in this embodiment, the safe braking distance S is estimated by combining the information of rainfall, light intensity, vehicle tilt state, road flatness and vehicle speed. In step 1), obtain the preset fitting parameter data table before the safe braking distance S. When obtaining the safe braking distance S, first obtain the current rainfall, light intensity, vehicle front and rear tilt status, and road flatness, and then search for the proposed model according to the above information. Obtain the curve distance fitting parameters K ₁ , K ₂ , and K ₃ according to the parameter data table, and obtain the safe braking distance S according to the current speed v obtained in step 1) and S=K ₁ v ² +K ₂ v+K ₃ .

In this embodiment, the rainfall is divided into sunny, light rain and heavy rain according to the numerical range, and the light intensity is divided into strong light, dim light and night according to the numerical range. The speed is divided into flat, normal and uneven according to the numerical range, and the driving speed of the car is divided into high speed, normal and low speed according to the numerical range. When setting the fitting parameters K ₁ , K ₂ , and K ₃ of the turning distance, first conduct an experiment on each element in the set of five factors including rainfall, light intensity, vehicle front and rear tilt, road flatness, and vehicle speed, and obtain Multiple sets of corresponding experimental values of speed and safe braking distance S under the corresponding factors of this element, and then obtain the fitting parameters K ₁ , K ₂ , K ₃ of the turning distance under the corresponding factors of this element through quadratic curve fitting of the least square method . For example, multiple sets of corresponding experimental values of speed and safe braking distance S under the corresponding factors of a certain element are shown in the following table:

i 0 1 2 3 4 5 6 7 8 9 x _i 10 20 30 40 50 60 70 80 90 100 y _i 7 12 15 twenty two 27 41 58 64 83 102

Among them, i is the serial number, x _i is the vehicle speed (in m/s), and y _i is the safe braking distance (in m).

Quadratic curve fitting using the least squares method:

$\left[\begin{array}{ccc}\mathrm{<span\; class="notranslate">\; 10</span>}& \underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}}{\overset{\mathrm{<span\; class="notranslate">\; 9</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}& \underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}}{\overset{\mathrm{<span\; class="notranslate">\; 9</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="i"\; filenames="HDA0000038974430000031.png"\; state="\{\{state\}\}">i</figure-callout></span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\\ \underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}}{\overset{\mathrm{<span\; class="notranslate">\; 9</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}& \underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}}{\overset{\mathrm{<span\; class="notranslate">\; 9</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="i"\; filenames="HDA0000038974430000031.png"\; state="\{\{state\}\}">i</figure-callout></span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}& \underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}}{\overset{\mathrm{<span\; class="notranslate">\; 9</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="3"\; label="i"\; filenames="HDA0000038974430000031.png"\; state="\{\{state\}\}">i</figure-callout></span>}}}^{\mathrm{<span\; class="notranslate">\; 3</span>}}\\ \underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}}{\overset{\mathrm{<span\; class="notranslate">\; 9</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="i"\; filenames="HDA0000038974430000031.png"\; state="\{\{state\}\}">i</figure-callout></span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}& \underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}}{\overset{\mathrm{<span\; class="notranslate">\; 9</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="3"\; label="i"\; filenames="HDA0000038974430000031.png"\; state="\{\{state\}\}">i</figure-callout></span>}}}^{\mathrm{<span\; class="notranslate">\; 3</span>}}& \underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}}{\overset{\mathrm{<span\; class="notranslate">\; 9</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}^{\mathrm{<span\; class="notranslate">\; 4</span>}}\end{array}\right]\left[\begin{array}{c}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\\ {\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}\\ {\mathrm{<span\; class="notranslate">\; <figure-callout\; id="3"\; label="K"\; filenames="HDA0000038974430000031.png"\; state="\{\{state\}\}">K</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}\end{array}\right]<span\; class="notranslate">\; =</span>\left[\begin{array}{c}\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}}{\overset{\mathrm{<span\; class="notranslate">\; 9</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}\\ \underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}}{\overset{\mathrm{<span\; class="notranslate">\; 9</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}\\ \underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}}{\overset{\mathrm{<span\; class="notranslate">\; 9</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}^{\mathrm{<span\; class="notranslate">\; no</span>}}{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}\end{array}\right]$

The fitting parameters of the turning distance are obtained: K ₁ =0.0095833 K ₂ =-0.012348, K ₃ =6.8833. Finally, any combination of the five factors of rainfall, light intensity, car tilt state, and road flatness can be combined to obtain a set of five factor combinations. Experiments are carried out on each element of the set, and finally 3 ^{to 5} sets of turning distance fitting parameters can be obtained. K ₁ , K ₂ , and K ₃ are stored in the fitting parameter data table 15 in advance. During the working process, it is only necessary to obtain the rainfall, light intensity, vehicle front and rear tilt status, and road flatness information according to the sensor data and adjust them into matching information, and then carry out strategy matching according to the adjustment results to find the preset turning distance fitting Parameters K ₁ , K ₂ , and K ₃ can quickly obtain the safe braking distance S.

As shown in Figure 4, the detailed steps for obtaining the curve fitting parameters K ₁ , K ₂ , and K ₃ in this embodiment are as follows:

① Make a decision on the amount of rainfall and determine whether it is sunny, light rain or heavy rain;

② Make a decision on the light intensity, and determine whether it belongs to strong light, dim light or night;

③Decision-making on the forward and backward tilt state of the car, and determine whether it is forward tilt, normal or backward tilt;

④ Make a decision on the flatness of the road, and determine whether it is flat, normal or uneven;

⑤ Make a decision on the driving speed of the car, and determine whether it belongs to high speed, normal or low speed;

⑥ According to the decision results of ①～⑤ above, query the fitting parameter data table to obtain the turning distance fitting parameters K ₁ , K ₂ , and K ₃ .

By adopting different control strategies, the irradiation distance is longer, the light is more concentrated and the brightness is stronger on the expressway with flat road surface and fast speed; Improve the lighting on the sidewalk on the driver's side; in rainy, snowy and foggy days with weak rain light intensity, by reducing the lighting angle of the scattered headlights, prevent the formation of concentrated light in front of the car, and reduce the light reflected by the ground water to the head The glare effect caused by the vehicle, at the same time, the lighting near the front and the left and right sides of the driver is improved; according to the speed of the vehicle, the angle of the steering wheel and the inclination of the body, the angle of the headlights is dynamically adjusted to ensure the safe lighting range of the curve. Under various bumpy roads and short-term road impacts (deceleration roadblocks), the headlight irradiation distance will not be adjusted frequently to prevent driver's eye fatigue.

Step 1) before obtaining the current speed v of the car includes the step of detecting the rotation of the headlights of the car. If the rotation of the headlights fails, reset the position of the headlights and stop the adaptive control of the headlights. In addition, if there is an error in initialization or a fault occurs during operation, the position of the headlight is also reset, and the adaptive control of the headlight is stopped. The initial position reset detection of the headlights can ensure safety and effectiveness, and prevent accidents in the adaptive control of the headlights.

The control signal output in step 4) is a gradual control signal. In this embodiment, the control signal is a PWM signal, and the gradually changing control signal means that the relationship between the control signal and the initial control signal is (PP ₀ )=nt, where P is the duty ratio parameter of the current output PWM signal, and P ₀ is the duty cycle parameter of the initial PWM signal, n is the amount of change for each adjustment, t is the adjustment time, and the value of t is related to the decision result of road flatness obtained in step ④ and the decision result of vehicle speed obtained in step ⑤. When driving at high speed and the road is uneven, the value of t is infinite, and the PWM signal remains unchanged; when the car is driving at high speed and the road is normal, the value of t is 0.75s; when the car is driving at high speed and the road is flat, the value of t is 0.5s; the car is running normally 1. When the road is uneven, t is 1.5s; when the car is driving normally and the road is normal, t is 1s; when the car is driving normally and the road is flat, t is 0.75s; The value of t is 2s; when the car is running at low speed and the road is normal, t takes the value of 1.5s; when the car is running at low speed and the road is flat, t takes the value of 1.25s. The relationship is shown in the table below:

Uneven normal flat high speed t=∞ t=0.75 t=0.5 normal t=1.5 t=1 t=0.75 low speed t=2 t=1.5 t=1.25

For the horizontal deflection angle ω, there is ω=mP, and for the vertical deflection angle β, there is β=m′P, where m is the ratio coefficient of the horizontal steering deflection angle of the vehicle light to the duty cycle, and m’ is the vertical deflection angle of the vehicle light and the duty ratio The proportional coefficient of the duty ratio, P is the duty ratio parameter of the output deflection control signal. In the process of adjusting the rotation angle, the output value of the control signal adopts the method of step-by-step change, and a variable is increased in each system cycle until the output value becomes the operation required value. Therefore, the output signal of each adjacent two cycles changes gradually, and no signal mutation occurs, thereby improving the continuous stability, safety and effectiveness of the headlight lighting, and reducing the wear caused by the sudden acceleration of the steering gear and noise, while avoiding the risk of loss of control due to sudden angle adjustments.

的比例系数，D为汽车前后轮轮轴之间的距离，L为前照灯与后轮轮轴的水平距离，C为前照灯水平时的照明距离、H为前照灯灯光光轴的离地高度。As shown in Figure 5, the adaptive control device for automobile headlights of the embodiment of the present invention includes a control unit 1 and a detection unit 2 and a drive mechanism 3 that are respectively connected to the control unit 1, and the detection unit 2 obtains the current speed v, steering wheel angle The front wheel body height change ΔH ₁ and the rear wheel body height change ΔH ₀ are output to the control unit 1, the control unit 1 obtains the safe braking distance S of the car at the current speed v, and the safe braking distance S and the detection unit 2 The output detection data obtains the horizontal deflection angle ω and the vertical deflection angle β corresponding to the current optimal lighting position of the headlamp, and converts the horizontal deflection angle ω and the vertical deflection angle β into rotation control signals for the headlamp and outputs them to The driving mechanism 3 controls the rotation of the headlights in real time, where v is the current speed of the car, and k is the steering angle of the front wheels and the steering wheel angle

D is the distance between the front and rear wheel axles of the car, L is the horizontal distance between the headlight and the rear wheel axle, C is the illumination distance when the headlight is horizontal, and H is the ground clearance of the light axis of the headlight high.

In this embodiment, the control unit 1 according to formula (101)

Formula (101)

Obtain the horizontal deflection angle ω corresponding to the current best lighting position of the headlight, according to formula (102)

$\mathrm{\&beta;}={\mathrm{the\; tan}}^{-1}\frac{\mathrm{\&Delta;}{h}_0-\mathrm{\&Delta;}{\mathrm{<figure-callout\; id="1"\; label="h"\; filenames="HDA0000038974430000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_1}{\mathrm{D.}}+{\mathrm{the\; tan}}^{-1}\frac{\frac{L-\mathrm{D.}}{\mathrm{D.}}(\mathrm{\&Delta;}{h}_0-\mathrm{\&Delta;}{h}_1)+h}{\mathrm{D.}}-{\mathrm{the\; tan}}^{-1}\frac{h}{C}$ Formula (102)

Get the vertical deflection angle β corresponding to the current optimal lighting position of the headlight, where v is the current speed of the car, and k is the front wheel steering angle and steering wheel angle D is the distance between the front and rear wheel axles of the car, L is the horizontal distance between the headlight and the rear wheel axle, C is the illumination distance when the headlight is horizontal, and H is the ground clearance of the light axis of the headlight high.

的方向盘转角传感器22、用于获取汽车的前轮车身高度变化量ΔH₁的前轮车身高度传感器23、用于获取汽车的后轮车身高度变化量ΔH₀的后轮车身高度传感器24、用于获取环境的雨量和光线强度的阳光雨量传感器25和用于获取汽车加速度的加速度传感器26，信号调理单元11将阳光雨量传感器25输出的雨量判定为晴天、小雨或者大雨，将阳光雨量传感器25输出的光线强度判定为强光、微光或者黑夜，根据前轮车身高度传感器23、后轮车身高度传感器24输出的高度信息判定汽车前后倾斜状态为前倾、正常或者后倾，根据加速度传感器26输出的加速度信息判定路面平坦度为平坦、正常或者不平坦，将速度传感器21输出的汽车行驶速度判定为高速、正常或者低速，控制决策单元12根据信号调理单元11的决策结果从拟合参数数据表15中查找拐弯距离拟合参数K₁、K₂、K₃，输出运算单元13获得安全制动距离S，并根据检测单元2输出的检测数据和安全制动距离S输出前照灯当前最佳照明位置对应的水平偏转角ω和垂直偏转角β，执行单元14将水平偏转角ω和垂直偏转角β转换为对前照灯的控制信号并输出至驱动机构3。As shown in Figure 5 and Figure 6, the control unit 1 includes a fitting parameter data table 15 and a signal conditioning unit 11, a control decision-making unit 12, an output operation unit 13 and an execution unit 14 connected in sequence, the fitting parameter data table 15 and the control The decision-making unit 12 is connected, and the detection unit 2 includes a speed sensor 21 for obtaining the current speed v of the automobile, and a steering wheel angle for obtaining the automobile.

Steering wheel angle sensor 22, the front wheel body height sensor 23 for obtaining the front wheel body height variation ΔH ₁ of the automobile, the rear wheel body height sensor 24 for obtaining the rear wheel body height variation ΔH ₀ of the automobile, Obtain the sunshine rain sensor 25 of the rainfall of environment and light intensity and be used to obtain the acceleration sensor 26 of automobile acceleration, the signal conditioning unit 11 judges the rainfall that sunshine rain sensor 25 outputs as sunny day, light rain or heavy rain, the output of sunshine rain sensor 25 The light intensity is judged as glare, low light or night, and the height information output by the front wheel vehicle height sensor 23 and the rear wheel vehicle height sensor 24 is used to determine whether the front and rear tilt state of the car is forward, normal or backward, and according to the output of the acceleration sensor 26 Acceleration information determines that the road surface flatness is flat, normal or uneven, and the vehicle speed output by the speed sensor 21 is determined as high speed, normal or low speed, and the control decision unit 12 selects from the fitting parameter data table 15 according to the decision result of the signal conditioning unit 11. Find the fitting parameters K ₁ , K ₂ , and K ₃ of the turning distance, and the output operation unit 13 obtains the safe braking distance S, and outputs the current optimal lighting of the headlight according to the detection data output by the detection unit 2 and the safe braking distance S The position corresponds to the horizontal deflection angle ω and the vertical deflection angle β. The execution unit 14 converts the horizontal deflection angle ω and the vertical deflection angle β into control signals for the headlights and outputs them to the drive mechanism 3 .

In this embodiment, the control unit 1 is connected to the sunlight and rain sensor 25 through the LIN bus, and connected to the speed sensor 21 and the steering wheel angle sensor 22 through the CAN bus. The front wheel vehicle height sensor 23 and the rear wheel vehicle height sensor 24 detect the change in vehicle height through the rotating rod on the transmission rod connected to the axle or wheel suspension. The front wheel vehicle height sensor 23 and the rear wheel vehicle height sensor 24 are usually placed Between the vehicle body and the suspension, the height of the vehicle body is judged by the switch state of the optocoupler component, and the information is generally collected by the electronically controlled suspension and then shared through the vehicle body network. For vehicles without electronically controlled suspension, it is only necessary to install a vehicle height sensor. The sunlight and rain sensor 25 is a sensor module produced by KSTAR, and the sunlight and rain sensor 25 is connected with the control unit 1 through the LIN bus. The sunlight and rain sensor 25 includes a light sensor, emitting and receiving diodes, the photosensitive sensor is a photoelectric tube, and the detected light intensity information is also transmitted to the control unit 1 through the LIN bus. The emitting and receiving diodes emit and receive infrared rays respectively. The light leaves the emitter diode and reaches the receiving diode after multiple reflections. If the windshield around the optical unit becomes wet or dirty, part of the reflected light will be lost, and the received light It is evaluated by the sun and rain sensor 25 and converted into a signal value. The micro-control element in the rain sensor can detect the change of the signal, and transmit the signal to the control unit 1 through the LIN bus. The acceleration sensor 26 adopts the ADXL330 acceleration sensor. The output signal of the ADXL330 acceleration sensor is the acceleration information of the three-dimensional coordinate axis. The acceleration value in the corresponding direction is obtained through AD sampling. The real-time monitoring of the acceleration can effectively judge the short-term vehicle body inclination caused by similar speed bumps Changes, combined with the vehicle height change information, can effectively judge the road condition.

In this embodiment, when judging the flatness of the road surface according to the acceleration information output by the acceleration sensor 26, by continuously using the acceleration information, if the acceleration change exceeds 0.5g, it is determined that a jump occurs, and then it is judged according to the number of jumps in a certain period road conditions. The relationship between the number of jumps and the flatness of the road surface in this embodiment is shown in the table below:

sampling time Sampling times jump threshold Number of jumps road flatness 0.1s 20 0.5g Greater than 6 Uneven 0.1s 20 0.5g 2～6 normal 0.1s 20 0.5g Less than 2 flat

In this embodiment, the main control chip of the control unit 1 adopts a freescale eight-bit controller MC9S08DZ60, which integrates modules such as SCI, CAN, A/D, PWM, and SPI. The power controller adopts MC33742. MC33742 is a system basic chip integrating CAN transceiver and power conversion function. The power controller is connected to the 12V power supply of the car, and the 12V power supply is converted into a 5V power supply to supply power to the control unit 1. As shown in Figure 7, after the system is powered on, the main control chip of the control unit 1 is first powered on and initialized. After the internal phase-locked loop works stably, the module registers such as SCI, CAN, I/O, and PWM are initialized. Configure the LIN bus and monitor the CAN bus data. Then call the self-inspection subroutine, PWM controls the steering gear to adjust the headlight to the maximum angle of up, down, left, and right, and reads the state of the I/O port at the same time. After the self-inspection is completed, judge the self-inspection result: if there is a fault, disable the adaptive control function of the headlight, send the headlight adjustment to the origin control command, and output the fault information; if there is no fault, read the rainfall, The signal conditioning unit 11 adjusts the above information to obtain information suitable for control decision-making; the control decision-making unit 12 adjusts the decision-making results for control decision-making, and selects the curve fitting parameters The output operation unit 13 obtains the safe braking distance of the automobile according to the curve distance fitting parameters, and outputs the horizontal deflection angle ω and the vertical deflection angle β according to the detection data and the safe braking distance output by the detection unit 2; the execution unit 14 will deflect the horizontal The angle ω and the vertical deflection angle β are converted into PWM signals and output.

As shown in FIG. 8 and FIG. 9 , the headlight 4 is connected with the power supply of the automobile through a contact 41 . The drive mechanism 3 includes a horizontal drive unit 31 and a vertical drive unit 32. The horizontal drive unit 31 includes a horizontal adjustment steering gear 310 for driving the headlamp to rotate in the horizontal direction. The input end of the horizontal adjustment steering gear 310 is connected to the control unit 1. The vertical driving unit 32 includes a vertical adjustment steering gear 320 for driving the headlamp to rotate in the vertical direction, and the input end of the vertical adjustment steering gear 320 is connected to the control unit 1 . In this embodiment, the horizontal drive unit 31 includes a horizontal cut-off point detection circuit 311, and the horizontal cut-off point detection circuit 311 outputs a detection signal to the control unit 1 when the headlamp rotates to the maximum horizontal angle position; the vertical drive unit 32 includes a vertical cut-off point detection circuit 311. The point detection circuit 321 , the vertical cut-off point detection circuit 321 outputs a detection signal to the control unit 1 when the headlamp rotates to the maximum rotation angle position in the vertical direction.

As shown in Figure 10, the horizontal cut-off point detection circuit 311 includes two cut-off point detection switches K1 and K2 horizontally arranged on both sides of the headlight, and the vertical cut-off point detection circuit 321 includes two vertically arranged on both sides of the headlight The cut-off detection switches K3 and K4, the cut-off detection switches K1, K2, K3 and K4 respectively correspond to the output ports PB0, PB1, PB2 and PB3, and the output ports PB0, PB1, PB2 and PB3 are connected to the control unit 1. When the headlight rotates to the maximum rotation angle position corresponding to the cut-off point detection switch, its corresponding output terminal outputs a high-level signal to the control unit 1 . At the time of initialization, the control unit 1 controls the horizontal adjustment steering gear 310 and the vertical adjustment steering gear 320 to perform the maximum angle rotation. After outputting the control signal, one or more of the ports connected to PB0, PB1, PB2 and PB3 do not input high power. Ping, then it can be judged that there is an error. At this time, the control unit 1 outputs an alarm signal through the CAN bus, and disables the adaptive control function of the headlight.

The above descriptions are only preferred implementations of the present invention, and the protection scope of the present invention is not limited to the above-mentioned embodiments, and all technical solutions under the idea of the present invention belong to the protection scope of the present invention. It should be pointed out that for those skilled in the art, some improvements and modifications without departing from the principles of the present invention should also be regarded as the protection scope of the present invention.

Claims (7)

1. A method for adaptive control of automobile headlights, characterized in that its implementation steps are as follows: 1) Obtain the current speed v of the car in real time, and obtain the safe braking distance S of the car at the current speed v; 2) Obtain the steering wheel angle of the car in real time

And according to formula (101)

Formula (101) Obtain the horizontal deflection angle ω corresponding to the current optimal lighting position of the headlight, where k is the steering angle of the front wheel and the steering wheel angle

The proportional coefficient of D is the distance between the front and rear wheel axles of the car; 3) Obtain the front wheel body height change ΔH ₁ and the rear wheel body height change ΔH ₀ in real time, and according to formula (102) $\mathrm{\&beta;}={\mathrm{the\; tan}}^{-1}\frac{\mathrm{\&Delta;}{h}_0-\mathrm{\&Delta;}{h}_1}{\mathrm{D.}}+{\mathrm{the\; tan}}^{-1}\frac{\frac{L-\mathrm{D.}}{\mathrm{D.}}(\mathrm{\&Delta;}{h}_0-\mathrm{\&Delta;}{h}_1)+h}{\mathrm{D.}}-{\mathrm{the\; tan}}^{-1}\frac{h}{C}$ Formula (102) The vertical deflection angle β corresponding to the current optimal lighting position of the headlight is obtained, where L is the horizontal distance between the headlight and the rear wheel axle, C is the lighting distance when the headlight is horizontal, and H is the distance of the light axis of the headlight height above the ground; 4) Output the control signal according to the above horizontal deflection angle ω and vertical deflection angle β to control the rotation of the headlight in real time; In the step 1), the preset fitting parameter data table is obtained before the safe braking distance S. When obtaining the safe braking distance S, the current rainfall, light intensity, vehicle front and rear tilt state and road flatness are obtained first, and then according to Find the fitting parameter data table for the above information to obtain the turning distance fitting parameters K ₁ , K ₂ , and K ₃ , and obtain the current speed v and S=K ₁ v ² +K ₂ v+K ₃ according to the current speed v obtained in the above step 1) Safe braking distance S. 2. The adaptive control method for automobile headlights according to claim 1, characterized in that: the detailed steps of obtaining the fitting parameters K ₁ , K ₂ , and K ₃ of the turning distance are as follows: ① Make a decision on the amount of rainfall and determine whether it is sunny, light rain or heavy rain; ② Make a decision on the light intensity, and determine whether it belongs to strong light, dim light or night; ③Decision-making on the forward and backward tilt state of the car, and determine whether it is forward tilt, normal or backward tilt; ④ Make a decision on the flatness of the road, and determine whether it is flat, normal or uneven; ⑤ Make a decision on the driving speed of the car, and determine whether it belongs to high speed, normal or low speed; ⑥ According to the decision results of ①～⑤ above, query the fitting parameter data table to obtain the turning distance fitting parameters K ₁ , K ₂ , and K ₃ . 3. The adaptive control method for automobile headlights according to claim 1 or 2, wherein the step 1) includes the step of detecting the rotation of the automobile headlights before obtaining the current speed v of the automobile, if If the rotation of the headlight fails, the position of the headlight is reset and the adaptive control of the headlight is stopped. 4. The adaptive control method for automobile headlights according to claim 1 or 2, characterized in that the control signal output in step 4) is a gradual control signal. 5. The adaptive control method for automobile headlights according to claim 4, characterized in that: the control signal is a PWM signal, and the gradual change control signal means that the relationship between the control signal and the initial control signal is ( PP ₀ )=nt, wherein P is the duty cycle parameter of the current output PWM signal, P ₀ is the duty cycle parameter of the initial PWM signal, n is the variation of each adjustment, and t is the adjustment time, and the value of t is Relevant to the road flatness decision result obtained in step ④ and the vehicle speed decision result obtained in step ⑤, when the car runs at high speed and the road is uneven, t takes an infinite value, and the PWM signal remains unchanged; when the car runs at high speed, When the road is normal, the value of t is 0.75s; when the car is driving at high speed and the road is flat, the value of t is 0.5s; when the car is driving normally and the road is uneven, the value of t is 1.5s; 1s; when the car is driving normally and the road is flat, the value of t is 0.75s; when the car is driving at a low speed and the road is uneven, the value of t is 2s; when the car is driving at a low speed and the road is normal, the value of t is 1.5s; When t takes the value of 1.25s. 6. An adaptive control device for automobile headlights, comprising a control unit (1), a detection unit (2) connected to the control unit (1), and a drive mechanism (3), characterized in that: the detection unit ( 2) Obtain the current speed v and steering wheel angle of the car in real time The front wheel body height change ΔH ₁ and the rear wheel body height change ΔH ₀ are output to the control unit (1), and the control unit (1) obtains the safe braking distance S of the car at the current speed v, and according to the Obtain the horizontal deflection angle ω and the vertical deflection angle β corresponding to the current optimal lighting position of the headlamp from the output information of the detection unit (2) and the safe braking distance S, and convert the horizontal deflection angle ω and the vertical deflection angle β In order to control the rotation of the headlight and output the signal to the drive mechanism (3) to control the rotation of the headlight in real time; the control unit (1) according to formula (101)

Formula (101) Obtain the horizontal deflection angle ω corresponding to the current best lighting position of the headlight, according to formula (102) $\mathrm{\&beta;}={\mathrm{the\; tan}}^{-1}\frac{\mathrm{\&Delta;}{h}_0-\mathrm{\&Delta;}{h}_1}{\mathrm{D.}}+{\mathrm{the\; tan}}^{-1}\frac{\frac{L-\mathrm{D.}}{\mathrm{D.}}(\mathrm{\&Delta;}{h}_0-\mathrm{\&Delta;}{h}_1)+h}{\mathrm{D.}}-{\mathrm{the\; tan}}^{-1}\frac{h}{C}$ Formula (102) Get the vertical deflection angle β corresponding to the current optimal lighting position of the headlight, where v is the current speed of the car, and k is the front wheel steering angle and steering wheel angle

D is the distance between the front and rear wheel axles of the car, L is the horizontal distance between the headlight and the rear wheel axle, C is the illumination distance when the headlight is horizontal, and H is the ground clearance of the light axis of the headlight Height; the control unit (1) includes a fitting parameter data table (15) and a signal conditioning unit (11), a control decision-making unit (12), an output calculation unit (13) and an execution unit (14), which are sequentially connected. The fitting parameter data table (15) is connected to the control decision-making unit (12), and the detection unit (2) includes a speed sensor (21) for obtaining the current speed v of the vehicle, a steering wheel angle for obtaining the vehicle

The steering wheel angle sensor (22), the front wheel body height sensor (23) used to obtain the vehicle body height variation of the front wheels ΔH ₁ , the rear wheel body height sensor used to obtain the vehicle body height change amount of the rear wheels ΔH ₀ (24), the sunlight and rain sensor (25) used to obtain the environmental rain and light intensity and the acceleration sensor (26) used to obtain the acceleration of the vehicle, the signal conditioning unit (11) outputs the sunlight and rain sensor (25) The rainfall is judged as sunny, light rain or heavy rain, and the light intensity output by the sunlight and rain sensor (25) is judged as strong light, dim light or night, according to the output of the front wheel vehicle height sensor (23) and the rear wheel vehicle height sensor (24) Determine whether the front and rear tilt state of the car is forward, normal or backward based on the height information, determine whether the road surface flatness is flat, normal or uneven according to the acceleration information output by the acceleration sensor (26), and determine the vehicle speed output by the speed sensor (21) is high speed, normal or low speed, the control decision unit (12) looks up the curve distance fitting parameters K ₁ , K ₂ , K from the fitting parameter data table (15) according to the decision result of the signal conditioning unit (11) _3. The output calculation unit (13) obtains the safe braking distance S, and outputs the level corresponding to the current optimal lighting position of the headlight according to the detection data output by the detection unit (2) and the safe braking distance S The deflection angle ω and the vertical deflection angle β, the execution unit (14) converts the horizontal deflection angle ω and the vertical deflection angle β into control signals for the headlights and outputs them to the drive mechanism (3). 7. The adaptive control device for automobile headlights according to claim 6, characterized in that: the driving mechanism (3) includes a horizontal driving unit (31) and a vertical driving unit (32), and the horizontal driving unit ( 31) Including a horizontal adjustment steering gear (310) for driving the headlight to rotate in the horizontal direction, the input end of the horizontal adjustment steering gear (310) is connected to the control unit (1), and the vertical driving unit (32) It includes a vertical adjustment steering gear (320) for driving the headlamp to rotate in the vertical direction, the input end of the vertical adjustment steering gear (320) is connected to the control unit (1), and the horizontal driving unit (31) includes a horizontal Cutoff point detection circuit (311), the horizontal cutoff point detection circuit (311) outputs a detection signal to the control unit (1) when the headlamp rotates to the maximum horizontal angle position; the vertical drive unit (32) includes a vertical A cut-off point detection circuit (321), the vertical cut-off point detection circuit (321) outputs a detection signal to the control unit (1) when the headlamp rotates to the maximum vertical angle position.

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