WO2024108932A1 - 一种车辆前照灯自动调平方法及装置 - Google Patents

一种车辆前照灯自动调平方法及装置 Download PDF

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Publication number
WO2024108932A1
WO2024108932A1 PCT/CN2023/095006 CN2023095006W WO2024108932A1 WO 2024108932 A1 WO2024108932 A1 WO 2024108932A1 CN 2023095006 W CN2023095006 W CN 2023095006W WO 2024108932 A1 WO2024108932 A1 WO 2024108932A1
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Prior art keywords
headlamp
vehicle
angle
vehicle height
distance
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PCT/CN2023/095006
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English (en)
French (fr)
Inventor
李丹
关忠旭
张航
史云霞
翟昭华
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中国第一汽车股份有限公司
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Publication of WO2024108932A1 publication Critical patent/WO2024108932A1/zh

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60Q—ARRANGEMENT OF SIGNALLING OR LIGHTING DEVICES, THE MOUNTING OR SUPPORTING THEREOF OR CIRCUITS THEREFOR, FOR VEHICLES IN GENERAL
    • B60Q1/00—Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor
    • B60Q1/02—Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor the devices being primarily intended to illuminate the way ahead or to illuminate other areas of way or environments
    • B60Q1/04—Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor the devices being primarily intended to illuminate the way ahead or to illuminate other areas of way or environments the devices being headlights
    • B60Q1/06—Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor the devices being primarily intended to illuminate the way ahead or to illuminate other areas of way or environments the devices being headlights adjustable, e.g. remotely-controlled from inside vehicle
    • B60Q1/08—Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor the devices being primarily intended to illuminate the way ahead or to illuminate other areas of way or environments the devices being headlights adjustable, e.g. remotely-controlled from inside vehicle automatically
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60Q—ARRANGEMENT OF SIGNALLING OR LIGHTING DEVICES, THE MOUNTING OR SUPPORTING THEREOF OR CIRCUITS THEREFOR, FOR VEHICLES IN GENERAL
    • B60Q1/00—Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor
    • B60Q1/02—Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor the devices being primarily intended to illuminate the way ahead or to illuminate other areas of way or environments
    • B60Q1/04—Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor the devices being primarily intended to illuminate the way ahead or to illuminate other areas of way or environments the devices being headlights
    • B60Q1/06—Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor the devices being primarily intended to illuminate the way ahead or to illuminate other areas of way or environments the devices being headlights adjustable, e.g. remotely-controlled from inside vehicle
    • B60Q1/08—Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor the devices being primarily intended to illuminate the way ahead or to illuminate other areas of way or environments the devices being headlights adjustable, e.g. remotely-controlled from inside vehicle automatically
    • B60Q1/10—Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor the devices being primarily intended to illuminate the way ahead or to illuminate other areas of way or environments the devices being headlights adjustable, e.g. remotely-controlled from inside vehicle automatically due to vehicle inclination, e.g. due to load distribution
    • B60Q1/115—Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor the devices being primarily intended to illuminate the way ahead or to illuminate other areas of way or environments the devices being headlights adjustable, e.g. remotely-controlled from inside vehicle automatically due to vehicle inclination, e.g. due to load distribution by electric means
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60Q—ARRANGEMENT OF SIGNALLING OR LIGHTING DEVICES, THE MOUNTING OR SUPPORTING THEREOF OR CIRCUITS THEREFOR, FOR VEHICLES IN GENERAL
    • B60Q1/00—Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor
    • B60Q1/02—Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor the devices being primarily intended to illuminate the way ahead or to illuminate other areas of way or environments
    • B60Q1/04—Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor the devices being primarily intended to illuminate the way ahead or to illuminate other areas of way or environments the devices being headlights
    • B60Q1/06—Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor the devices being primarily intended to illuminate the way ahead or to illuminate other areas of way or environments the devices being headlights adjustable, e.g. remotely-controlled from inside vehicle
    • B60Q1/08—Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor the devices being primarily intended to illuminate the way ahead or to illuminate other areas of way or environments the devices being headlights adjustable, e.g. remotely-controlled from inside vehicle automatically
    • B60Q1/12—Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor the devices being primarily intended to illuminate the way ahead or to illuminate other areas of way or environments the devices being headlights adjustable, e.g. remotely-controlled from inside vehicle automatically due to steering position

Definitions

  • the invention relates to the technical field of vehicles, and in particular to a method and a device for automatically leveling a vehicle headlamp.
  • the inertial measurement unit is used to measure acceleration and angular velocity and calculate the posture of the vehicle body, and then send the calculated posture to the corresponding processor.
  • the processor determines whether the vehicle is in a stationary state according to the external input vehicle speed signal. If the vehicle is in a stationary state, the acceleration measured by the inertial measurement unit is considered to be the acceleration of gravity.
  • the posture of the vehicle body at this time can be determined according to its relative direction with the inertial measurement unit.
  • the processor sends a corresponding instruction to the stepper motor connected to the headlamp according to the posture at this time, and the stepper motor rotates vertically so that the illumination direction of the headlamp meets the regulatory requirements; if the vehicle is in a moving state, the inertial measurement unit measures the acceleration of the vehicle to determine whether the vehicle is in an acceleration/braking condition.
  • the processor sends an instruction to the stepper motor according to this information to control the headlamp to rotate vertically to offset the change in the illumination direction of the headlamp caused by the acceleration/deceleration of the vehicle.
  • the above schemes are highly dependent on the acceleration measured by the inertial measurement unit.
  • the acceleration measured by the inertial measurement unit usually has high noise, which may affect the accuracy of the stepper motor output.
  • the frequent shaking of the road surface will cause the measurement results of the inertial measurement unit to change frequently and significantly, making the stepper motor position unstable.
  • the system not only fails to provide safety lighting, but also causes visual discomfort to the driver and drivers of oncoming vehicles.
  • the purpose of the present invention is to provide a method for automatically leveling vehicle headlights, which obtains the rotation angles of the stepper motors of the left and right headlights through real-time estimation of the vehicle state and the road state, thereby realizing the automatic leveling function of the headlights.
  • the present invention provides a method for automatically leveling a vehicle headlamp, comprising:
  • the headlamp control signal is sent to the headlamp, so that the headlamp performs light leveling according to the headlamp control signal.
  • the vehicle headlamp automatic leveling method further includes:
  • the headlamp locks the light angle according to the headlamp control signal.
  • the vehicle height change signals of the plurality of preset positions include: a relative change in the left front vehicle height, a relative change in the left rear vehicle height, a relative change in the right front vehicle height, and a relative change in the right rear vehicle height;
  • Calculating the vehicle posture information according to the vehicle height change signals at the plurality of preset positions includes:
  • the vehicle posture information is calculated based on the relative change in the front vehicle height, the relative change in the right rear vehicle height, the distance between the left front vehicle height sensor and the left rear vehicle height sensor, and the distance between the left front vehicle height sensor and the right front vehicle height sensor.
  • obtaining the headlamp angle information according to the vehicle posture information and the initial aiming angle includes:
  • the headlamp angle information is calculated based on the vehicle posture information, the initial illumination angle, the projection of the distance between the left headlamp and the front axle on the X-axis of the vehicle's sprung mass coordinate system, the distance between the left headlamp and the right headlamp, the wheelbase, the target illumination distance, and the height of the vehicle's center of gravity from the ground.
  • the vehicle height change signals of the plurality of preset positions include: a relative change amount of the left front vehicle height, a relative change amount of the left rear vehicle height;
  • Calculating the vehicle posture information according to the vehicle height change signals at the plurality of preset positions includes:
  • the vehicle posture information is calculated according to the relative change in the left front vehicle height, the relative change in the left rear vehicle height, and the distance between the left front vehicle height sensor and the left rear vehicle height sensor.
  • obtaining the headlamp angle information according to the vehicle posture information and the initial aiming angle includes:
  • the headlamp angle information is calculated based on the vehicle posture information, the initial aiming angle, the headlamp installation height, the projection of the distance between the left headlamp and the front axle on the x-axis of the vehicle sprung mass coordinate system, the wheelbase, the target irradiation distance, and the height of the vehicle's center of gravity from the ground.
  • acquiring the target irradiation distance includes:
  • generating a headlamp control signal according to the headlamp angle information includes:
  • a headlamp control signal is generated according to a lower limit of an output angle, an upper limit of an output angle, an anti-shake threshold, a control cycle, an output angle of the stepper motor at a previous moment, a limiting function, and an output angle scaling value at a current moment.
  • obtaining the output angle scaling value at the current moment includes:
  • the output angle scaling value at the current moment is calculated according to the scaling factor, the left headlamp output angle and/or the right headlamp output angle.
  • the present invention provides an automatic leveling device for vehicle headlights, the automatic leveling device for vehicle headlights comprising:
  • a road condition information acquisition module wherein the road condition information acquisition module is used to acquire road condition information
  • a judgment module used to judge whether the current road surface is a rough road surface according to the road condition information
  • a vehicle height change signal acquisition module wherein the vehicle height change signal acquisition module is used to acquire vehicle height change signals of a plurality of preset positions when the judgment result of the judgment module is no;
  • a posture information acquisition module the posture information acquisition module is used to calculate the vehicle posture information according to the vehicle height change signals at the plurality of preset positions;
  • An initial aiming angle acquisition module wherein the initial aiming angle acquisition module is used to acquire an initial aiming angle
  • a headlamp angle information acquisition module wherein the headlamp angle information acquisition module is used to obtain the headlamp angle information according to the vehicle posture information and the initial irradiation point when the judgment result of the judgment module is no;
  • a headlight control signal acquisition module the headlight control signal acquisition module is used to generate a headlight control signal according to the headlight angle information
  • a sending module is used to send the headlight control signal to the headlight, so that the headlight performs light leveling according to the headlight control signal.
  • the vehicle headlamp automatic leveling method provided by the present invention generates a control signal based on a vehicle body height change signal, has higher stability and robustness than an inertial measurement element solution, and can simultaneously provide three posture data of pitch angle, roll angle and vertical displacement for output angle calculation, and adaptively adjusts the illumination direction of the headlamp vertically when the vehicle posture changes, so that its illumination range remains stable. Avoid potential risks of traffic accidents caused by its irradiation position being too high or too low.
  • FIG1 is a schematic diagram showing the relationship between the position of the light-dark cutoff line and the irradiation distance according to the present invention.
  • FIG. 2 is a schematic flow chart of the method for automatically leveling vehicle headlights according to the present invention.
  • FIG. 3 is a schematic diagram of the vehicle body posture change according to the present invention.
  • FIG. 4 is a schematic diagram of the output angle calculation of the present invention.
  • FIG. 5 is a schematic diagram of the vehicle state during the vehicle acceleration process after using the ALS method described in the present invention.
  • FIG6 is a schematic diagram of the vehicle state at the moment when the vehicle starts braking after using the ALS method described in the present invention.
  • FIG. 7 is a schematic diagram of the vehicle state when the vehicle is completely stopped after using the ALS method described in the present invention.
  • FIG8 is a schematic diagram of the vehicle state during the vehicle acceleration process without the ALS method described in the present invention.
  • FIG. 9 is a schematic diagram of the vehicle state when the vehicle starts braking without the ALS method described in the present invention.
  • FIG. 10 is a schematic diagram of the vehicle state when the vehicle is completely stopped without the ALS method described in the present invention.
  • FIG. 11 is a flow chart of road surface recognition according to the present invention.
  • FIG12 is a flow chart of the decision tree of the present invention.
  • FIG. 13 is a schematic flow chart of the method for automatically leveling vehicle headlights according to the present invention.
  • FIG. 14 is a schematic diagram of an electronic device for implementing the method for automatically leveling vehicle headlights provided by the present invention.
  • FIG. 13 is a schematic flow chart of a method for automatically leveling vehicle headlights according to an embodiment of the present invention.
  • the present invention provides a method for automatically leveling a vehicle headlamp, comprising:
  • the headlamp control signal is sent to the headlamp, so that the headlamp performs light leveling according to the headlamp control signal.
  • the vehicle headlamp automatic leveling method provided by the present invention generates a control signal based on a vehicle body height change signal. Compared with an inertial measurement element solution, it has higher stability and robustness, and can simultaneously provide three posture data of pitch angle, roll angle and vertical displacement for output angle calculation. When the vehicle posture changes, the illumination direction of the headlamp is adaptively adjusted vertically, so that its illumination range remains stable, avoiding the potential risk of traffic accidents caused by its illumination position being too high or too low.
  • the method for automatically leveling vehicle headlights further includes:
  • the headlamp locks the light angle according to the headlamp control signal.
  • the vehicle height change signals of the plurality of preset positions include: a relative change in the left front vehicle height, a relative change in the left rear vehicle height, a relative change in the right front vehicle height, and a relative change in the right rear vehicle height;
  • Calculating vehicle posture information based on vehicle height change signals at multiple preset positions includes:
  • the vehicle posture information is calculated based on the relative change in the left front body height, the relative change in the left rear body height, the relative change in the right front body height, the relative change in the right rear body height, the distance between the left front body height sensor and the left rear body height sensor, and the distance between the left front body height sensor and the right front body height sensor.
  • the vehicle posture information is calculated according to the following formula:
  • ⁇ is the pitch angle of the vehicle sprung mass relative to the vehicle unsprung mass
  • Z fl is the relative change in the left front body height
  • Z rl is the relative change in the left rear body height
  • Z fr is the relative change in the right front body height
  • Z rr is the relative change in the right rear body height
  • ⁇ is the roll angle of the vehicle sprung mass relative to the vehicle unsprung mass
  • ⁇ z is the z-axis displacement of the vehicle sprung mass relative to the vehicle unsprung mass
  • L 0 is the distance between the left front body height sensor and the left rear body height sensor
  • W 0 is the distance between the left front body height sensor and the right front body height sensor.
  • the vehicle posture information includes: the pitch angle of the vehicle's sprung mass relative to the vehicle's unsprung mass, the roll angle of the vehicle's sprung mass relative to the vehicle's unsprung mass, and the z-axis displacement of the vehicle's sprung mass relative to the vehicle's unsprung mass.
  • obtaining the headlamp angle information according to the vehicle posture information and the initial aiming angle includes:
  • the headlamp turning angle information is calculated based on the vehicle posture information, the initial illumination angle, the projection of the distance between the left headlamp and the front axle on the X-axis of the vehicle's sprung mass coordinate system, the distance between the left headlamp and the right headlamp, the wheelbase, the target illumination distance, and the height of the vehicle's center of gravity from the ground.
  • the headlamp angle information is calculated according to the following formula:
  • ⁇ Lout is the output angle of the left headlamp
  • L1 is the projection of the distance between the left headlamp and the front axle on the x-axis of the vehicle sprung mass coordinate system
  • W1 is the distance between the left headlamp and the right headlamp
  • L is the wheelbase
  • D(v) is the target irradiation distance
  • ⁇ 0 is the initial aiming angle
  • H is the height of the vehicle center of gravity from the ground
  • ⁇ Rout is the output angle of the right headlamp.
  • the vehicle height change signals of the plurality of preset positions include: a relative change in the left front vehicle height, a relative change in the left rear vehicle height;
  • Calculating vehicle posture information based on vehicle height change signals at multiple preset positions includes:
  • the vehicle posture information is calculated based on the relative change in the left front vehicle height, the relative change in the left rear vehicle height, and the distance between the left front vehicle height sensor and the left rear vehicle height sensor.
  • ⁇ is the pitch angle of the vehicle sprung mass relative to the vehicle unsprung mass
  • Zf is the relative change in the left front body height
  • Zr is the relative change in the left rear body height
  • ⁇ is the roll angle of the vehicle sprung mass relative to the vehicle unsprung mass
  • ⁇ z is the z-axis displacement of the vehicle sprung mass relative to the vehicle unsprung mass
  • L0 is the distance between the left front body height sensor and the left rear body height sensor.
  • obtaining the headlamp angle information according to the vehicle posture information and the initial aiming angle includes:
  • initial aiming angle, headlamp installation height, left headlamp and front axle is calculated based on the projection of the distance on the X-axis of the vehicle's sprung mass coordinate system, the wheelbase, the target irradiation distance, and the height of the vehicle's center of gravity from the ground.
  • the headlamp angle information is calculated according to the following formula:
  • ⁇ out is the output angle of the headlamp
  • H0 is the installation height of the headlamp
  • L1 is the projection of the distance between the left headlamp and the front axle on the x-axis of the vehicle sprung mass coordinate system
  • L is the wheelbase
  • D(v) is the target irradiation distance
  • H is the height of the vehicle's center of gravity from the ground
  • ⁇ 0 is the initial aiming angle.
  • the output angle of the headlamp is positive when it is downward; the output angles of the left headlamp and the right headlamp are the same.
  • obtaining the target irradiation distance includes:
  • the target irradiation distance is calculated according to the following formula:
  • H0 is the headlight installation height and v is the vehicle speed.
  • generating a headlamp control signal according to the headlamp angle information includes:
  • a headlamp control signal is generated according to a lower limit of an output angle, an upper limit of an output angle, an anti-shake threshold, a control cycle, an output angle of the stepper motor at a previous moment, a limiting function, and an output angle scaling value at a current moment.
  • the output angle of the stepper motor of the vehicle headlight is calculated according to the following formula:
  • ⁇ fout (t) is the output angle of the stepper motor at time t (current time)
  • ⁇ min is the lower limit of the output angle
  • ⁇ max is the upper limit of the output angle
  • ⁇ thres is the anti-shake threshold
  • t0 is the control period
  • ⁇ fout ( tt0 ) is the output angle of the stepper motor at time tt0
  • f( ⁇ out -1 (t)) is the limiting function
  • ⁇ out -1 (t) is the output angle scaling value at time t.
  • Obtaining the output angle scaling value at the current time (time t) includes:
  • the output angle at time t is calculated according to the following formula:
  • ka is the scaling factor
  • ⁇ (i) is the left headlamp output angle and/or the right headlamp output angle
  • a vehicle headlamp automatic leveling method provided by the present invention is described in detail below with reference to a specific embodiment. It should be noted that this embodiment is not a limitation of the present invention.
  • the present invention provides an automatic leveling method for vehicle headlamps (ALS, Automotive Headlamp Leveling System), which takes into account the automatic leveling of the vehicle headlamp's low beam when the vehicle is driving on a horizontal and flat road surface, a rough road surface, on a slope, in transition between two sections of road surfaces with different slopes, and when driving over speed bumps or large potholes.
  • ALS Automotive Headlamp Leveling System
  • a horizontal road surface refers to a road surface that is flat, has no bumps, and is perpendicular to the direction of gravity.
  • a horizontal road surface as shown in Figure 1, it is easy to imagine from the definition of the light-dark cutoff line that since the light emitted by the headlamp can produce a sharp light-dark dividing line on the vertical screen within a certain distance ahead, it should also be able to produce a certain light-dark dividing line on the horizontal road ahead.
  • the projection of the distance between the light-dark dividing line and the headlamp on the ground is called the "illumination distance" of the headlamp, recorded as D.
  • the illumination distance on the horizontal road ahead can be calculated:
  • ⁇ 0 is the initial aiming angle, also known as the initial downward tilt angle, which is positive when it is facing downward.
  • the value of ⁇ 0 can be calculated by the following formula:
  • D0 is the distance between the headlight and the light distribution screen
  • D0 is 10m
  • h0 is the height of the light-dark cut-off line
  • H0 - h0 is 0.1m; due to the different installation conditions of the low beam lights on actual vehicles, the value of ⁇ 0 is not exactly the same.
  • GB4785 stipulates that the initial aiming of the low beam lights should be between -1.0% and -1.5%, that is, 0.57° ⁇ ⁇ 0 ⁇ 0.86°.
  • the point located on the light-dark dividing line on the ground and directly in front of the left and right headlights is called the aiming point of the left and right headlights. It can be considered that the area between the headlights and their aiming points is within the effective lighting range of the headlights. Therefore, “keeping the headlight illumination range stable" can be equivalently described as “keeping the position of the aiming points of the left and right headlights stable.”
  • the coordinate system is established with the unsprung mass of the vehicle as the reference, the direction of the line connecting the center of the front wheel axle and the center of the rear wheel axle is the x-axis direction (pointing to the front of the vehicle), the direction of the wheel axle is the y-axis direction (pointing to the left of the vehicle), and the direction perpendicular to the xy plane is the z-axis direction (pointing to the top of the vehicle);
  • the coordinate system is established with the sprung mass of the vehicle as the reference, the direction of the symmetry axis of the vehicle chassis is the x-axis direction (pointing to the front of the vehicle), the direction perpendicular to the chassis is the z-axis direction (pointing to the top of the vehicle), and the direction perpendicular to the xz plane is the y-axis direction (pointing to the left of the vehicle).
  • the xy plane of the unsprung mass coordinate system is always parallel to the xy plane of the inertial system, while the position of the sprung mass coordinate system relative to the unsprung mass coordinate system will change with changes in load, vehicle speed, etc. Since the headlight is fixedly connected to the sprung mass, its coordinates in the unsprung mass coordinate system and The irradiation direction will also change accordingly, and thus the position of its aiming point will also change. In order to "offset" this change as much as possible, it is necessary to output a turning angle ⁇ Lout and ⁇ Rout to the left and right headlights respectively.
  • LA is a function of the position A of the sprung mass relative to the unsprung mass and the left headlamp turning angle ⁇ Lout output by the ALS method
  • RA is a function of the position A of the sprung mass relative to the unsprung mass and the right headlamp turning angle ⁇ Rout output by the ALS method
  • Formula (1-4) is the goal to be achieved by the vehicle headlight automatic leveling method described in the present invention.
  • the raw data measured by the sensors need to be converted into usable, high-quality ALS method input signals.
  • the sensor measurement signals do not need to be filtered. They only need to be converted into dimensions and subtracted from the zero point before they can be used as the input of the ALS method.
  • the digital signal output by the vehicle height sensor contains noise and needs to be filtered.
  • the height value measured by the vehicle height sensor when the vehicle is in the rated state is called the zero point of the sensor.
  • the posture of the sprung mass should also be based on the posture in the rated state as a reference.
  • the measurement values of the four body height sensors in this state are Z 0_fl , Z 0_fr , Z 0_rl , and Z 0_rr (fl: left front, fr: right front, rl: left rear, rr: right rear). These four values are called the "zero points" of the four body height sensors.
  • the measurement values of the four vehicle height sensors also change accordingly.
  • the relative position between two coordinate systems in three-dimensional space can be described by six parameters: Euler angles in three directions (pitch angle - ⁇ - rotation around the Y axis, roll angle - ⁇ - rotation around the X axis, yaw angle - -rotation around the Z axis) and relative displacements ⁇ x, ⁇ y, ⁇ z in three dimensions. It is impossible to calculate the above six parameters using the four values of Z fl , Z fr , Z rl , and Z rr.
  • the yaw angle of the sprung mass relative to the unsprung mass coordinate system is The x-axis displacement ⁇ x and the y-axis displacement ⁇ y can be ignored. It can be assumed that there are only pitch motion ⁇ , roll motion ⁇ and z-axis motion ⁇ z between the two coordinate systems.
  • the order of change from the unsprung mass coordinate system to the sprung mass coordinate system is ⁇ - ⁇ - ⁇ z (all with the unsprung mass coordinate system as a reference).
  • the coordinates of the connection points of the four vehicle height sensors and the sprung mass are respectively P 0_fl , P 0_fr , P 0_rl , and P 0_rr .
  • the projection of the distance between P 0_fl and P 0_fr on the y-axis is W 0 (the distance between the left front vehicle height sensor and the right front vehicle height sensor).
  • the projection of the distance between P 0_fl and P 0_rl on the x-axis is L 0 (the distance between the left front vehicle height sensor and the left rear vehicle height sensor).
  • the coordinates of the four points are rotated/translated in the three directions of ⁇ - ⁇ - ⁇ z in turn to obtain the coordinates of the connection points of the four sensors and the sprung mass after the posture change: P fl , P fr , P rl , P rr (i.e., the coordinates of the four vertices of the solid line frame in FIG3 ):
  • RX is the rotation transformation matrix of the sprung mass around the X-axis
  • RY is the rotation transformation matrix of the sprung mass around the Y-axis
  • ⁇ is the roll angle of the sprung mass relative to the unsprung mass
  • ⁇ is the pitch angle of the sprung mass relative to the unsprung mass
  • ⁇ z represents the z-axis displacement of the sprung mass relative to the unsprung mass
  • the X-axis and Y-axis coordinates of the four points Pfl , Pfr , Prl , and Prr do not participate in the subsequent calculations, and are replaced by symbols such as xfl and yfl in the formula.
  • the difference between the Z-axis coordinates of Pfl and P0_fl is the value of Zfl , and the same is true for Zfr , Zrl , and Zrr , that is:
  • Equations (2-5), (2-7), and (2-9) are the sprung mass posture estimation methods based on four vehicle height sensors:
  • the pitch angle ⁇ is positive when the head is raised
  • the roll angle ⁇ is positive when the left is higher and the right is lower.
  • the simulation verification was carried out through veDYNA, and the simulation results showed that the pitch angle, roll angle, and z-axis displacement estimation method based on the vehicle height sensor proposed in the present invention (Formula 2-10) has high reliability.
  • the two-sensor configuration can be considered as a special case of four sensors, that is, the left front sensor measurement under two-sensor input can be simultaneously considered as the left front sensor and right front sensor measurement under four-sensor input, and the left rear sensor measurement under two-sensor input can be simultaneously considered as the left rear sensor and right rear sensor measurement under four-sensor input, that is:
  • Zf is the relative height change of the left front vehicle height sensor
  • Zr is the relative height change of the left rear vehicle height sensor
  • the vehicle's headlamp angles ⁇ Lout and ⁇ Rout are derived from the position A of the vehicle's sprung mass relative to the unsprung mass and the initial aiming points LA0 and RA0 :
  • the sprung mass coordinate system and the unsprung mass coordinate system completely overlap.
  • the projection of the distance between the headlamp and the front axle on the x-axis be L1
  • the distance between the left and right headlamps be W1
  • the height of the vehicle's center of gravity from the ground be H
  • the height of the headlamp from the ground be H0 .
  • the coordinates of the initial position PL0 of the left headlamp can be obtained (assuming that the distances from the vehicle's center of gravity to the front and rear axles of the vehicle are equal):
  • the coordinates of the initial aiming point P LA0 of the left headlamp can be obtained:
  • the sprung mass coordinate system undergoes a rotational translation transformation relative to the unsprung mass coordinate system, and the transformation sequence is ⁇ - ⁇ - ⁇ z (all with the unsprung mass coordinate system as a reference). Since the left headlamp is fixedly connected to the sprung mass coordinate system, its coordinates in the sprung mass coordinate system remain unchanged and are still P L0 ; the initial aiming point P LA0 of the left headlamp (i.e., the desired aiming point after the posture change) remains unchanged in the unsprung mass coordinate system, so its coordinates P LA in the sprung mass coordinate system are obtained by the translation transformation in the z-axis direction and the inverse transformation of the XY Euler angles:
  • RX is the rotation transformation matrix of the vehicle around the X-axis
  • RY is the rotation transformation matrix of the vehicle around the Y-axis
  • ⁇ is the roll angle of the sprung mass relative to the unsprung mass
  • ⁇ is the pitch angle of the sprung mass relative to the unsprung mass
  • ⁇ z is the z-axis displacement of the sprung mass relative to the unsprung mass.
  • the purpose of the present invention is to adjust the aiming direction of the left headlamp from the initial direction (the angle with the xz plane is 0, and the angle with the x-axis is ⁇ 0 ) to the desired direction.
  • the left headlamp has two degrees of rotational freedom in its aiming direction, namely, rotation in the xz plane (i.e., up and down rotation) and rotation in the xy plane (i.e., left and right rotation).
  • the headlamp needs to adjust its aiming direction to direction; but in fact, the calculation results show that L x and L z are of the same order of magnitude, while the value of Ly is only about 0.01% of the former two.
  • the headlamp does not need to be adjusted left and right, and only needs to be rotated up and down to achieve the goal.
  • the final angle between the left headlamp irradiation direction and the x-axis i.e., the downward deflection angle of the headlamp
  • the vertical adjustment angle that the left headlamp needs to output is the difference between the initial vertical angle and the required vertical angle, that is:
  • Formulas (3-1)(3-2)(3-3)(3-4)(3-5)(3-6) are the complete contents of the algorithm for automatic leveling of the left headlamp on a flat and horizontal road surface.
  • the algorithm for calculating the left headlamp output angle ⁇ Lout can be obtained using the four sensor measurement value changes Z fl , Z rl , Z fr , and Z rr :
  • the calculation methods of the output angles of the left and right headlights are basically the same.
  • ⁇ Rout of the right headlight it is only necessary to change the y-axis coordinates of the two points L0 and L A0 in the first step to their opposite numbers, that is,
  • H0 is the installation height of the headlamp
  • L1 is the projection of the distance between the left headlamp and the front axle on the X-axis of the vehicle sprung mass coordinate system
  • L is the wheelbase
  • D(v) is the target irradiation distance
  • H is the height of the vehicle's center of gravity from the ground
  • ⁇ 0 is the initial aiming angle
  • the output angle of the headlamp is positive when it is downward;
  • the output angle was simulated by MATLAB.
  • the value of ⁇ z was fixed at 0.
  • the values of ⁇ and ⁇ were adjusted in the range of 0 to 2°.
  • the output angle of the left headlamp was approximately in direct proportion to the input pitch angle and roll angle.
  • the values of ⁇ and ⁇ were fixed at 0.
  • the value of ⁇ z was adjusted in the range of ⁇ 0.25m.
  • the output angle of the left headlamp was also approximately in direct proportion to ⁇ z.
  • veDYNA is used to simulate the process of the vehicle accelerating from rest for a period of time (during four gear changes) and then braking to a stop.
  • the three moments of the vehicle acceleration, braking, and complete stop are captured, and the displacement, speed, acceleration, and pitch angle are recorded during the driving process as the real-time motion status of the vehicle.
  • the height value measured by the vehicle height sensor is recorded as input to calculate the pitch attitude and vertical displacement of the vehicle body.
  • the top of the figure is an animation that reflects the movement of the vehicle and the light.
  • the light illumination range is marked, the upper edge of the area is the cut-off line, and the right line is the imaginary light distribution screen, which is always 10m in front of the headlight.
  • the vehicle body and the light will move with the pitch angle and z-axis displacement of the sprung mass.
  • the position of the cut-off line on the imaginary light distribution screen remains almost unchanged.
  • the headlight angle output by the ALS method is close to the input pitch angle. Due to the effect of ALS, the absolute value of the height change of the cut-off line does not exceed 3cm at most, and does not exceed 1cm in most of the time.
  • ka is the scaling factor
  • ⁇ (i) is the output angle of the left headlight or the output angle of the right headlight when there are four vehicle height sensors
  • the step angle of the stepper motor used in this embodiment is 0.00158°, and the position codes corresponding to the zero position, the upper limit position and the lower limit position are 3288, 4863 and 0 respectively, so that the motor output angle limit values are 2.49° upward and 5.19° downward.
  • ⁇ max 1.43°- ⁇ 0 + ⁇ b , where ⁇ b is a calibrable variable.
  • the calibration method is: first set the value of ⁇ b to 0, and apply extreme load to the vehicle. If the aiming point cannot be adjusted back to the range allowed by the regulations, then slightly increase the value of this parameter. Repeat the above process until the headlamp can be adjusted back to the range allowed by the regulations through the ALS under extreme load, and then take the value of ⁇ b at this time as the final result.
  • the output angle obtained by the ALS algorithm may change frequently due to factors such as changes in road input, vehicle acceleration and deceleration, and sensor noise. If the unprocessed output angle is used as the input of the stepper motor control module, the headlight will frequently shake, which will affect the driver's visual experience and even the driving safety of the vehicle. On the basis of filtering the sensor signal, the output angle also needs to be anti-shake processed, that is, a threshold ⁇ thres is set for the change in the output angle to limit the shake of the headlight. If the change in the output angle is less than this threshold, the angle input to the stepper motor control module remains unchanged.
  • the function of the headlight output angle ⁇ fout (t) used to calculate the motor target position with respect to ⁇ out (t) is:
  • ⁇ fout (t) is the output angle of the stepper motor at time t
  • ⁇ min is the lower limit of the output angle
  • ⁇ max is the upper limit of the output angle
  • ⁇ thres is the anti-shake threshold
  • t 0 is the control period
  • ⁇ fout (tt 0 ) is the output angle of the stepper motor at time tt 0
  • f( ⁇ out-1 (t)) is the limiting function
  • the limiting function satisfies:
  • the target position of the stepper motor is determined by the output rotation angle of the stepper motor.
  • the performance indicators of the output angle of the ALS method can be considered from three aspects: response speed, following accuracy, and stability (i.e., anti-shake ability). These three performance indicators are affected by the anti-shake threshold ⁇ thres and the filter window width n. As ⁇ thres increases, the following accuracy of ALS decreases and the stability improves; as n increases, the response speed of ALS decreases and the stability improves.
  • the vehicle driving state is divided into three types: stationary state, rapid acceleration/deceleration state and slow speed change state. These three driving states correspond to three different working modes of ALS: static mode, dynamic mode and speed following mode:
  • Static mode When the vehicle is stationary, the ALS system works in static mode. At this time, the main factor causing the change in the headlight angle is the change in load. In static mode, the value of ⁇ thres is small, which is used to improve the following accuracy; the value of n is large, which is used to improve stability.
  • the conditions for the vehicle to enter static mode are: 1) The starting state is Running (engine model) or Ready (electric model); 2) The vehicle is stationary; 3) Initialization has been completed; 4) The low beam headlight is turned on;
  • the conditions for the vehicle to enter dynamic mode are: a) the starting state is Running (engine model) or Ready (electric model); b) the vehicle is in motion; c) the gear is in forward gear; d) initialization has been completed; e) the low beam has been turned on; f) the system determines that the current working condition is sudden acceleration or deceleration; g) the vehicle height sensor signal changes; h) the ALS controller has completed initialization;
  • Speed following mode When the vehicle is driving steadily, at a certain speed and with very low acceleration, the ALS system works in speed following mode. At this time, the main factor causing the change in the headlight angle is the change in the target illumination distance caused by the slow change in vehicle speed. In speed following mode, the value of n is large, and the value of ⁇ thres is also large, both of which are to prevent frequent jitter of the output angle.
  • the conditions for the vehicle to enter the speed following mode are: 1) the starting state is Running (engine model) or Ready (electric model); 2) the vehicle is in motion; 3) the gear is in forward gear; 4) initialization has been completed; 5) the low beam has been turned on; 6) the system determines that the current working condition is a slow speed change condition; 7) the ALS controller has completed initialization.
  • the anti-shake threshold and the filter window width are obtained by actual vehicle calibration according to different vehicle models and the number of vehicle height sensors.
  • the present invention only provides the selection trend of the anti-shake threshold and the filter window width.
  • the ALS method on a horizontal road is obtained when the vehicle is traveling at a low speed.
  • the stopping sight distance of the vehicle also increases. This requires that the illumination range of the headlights needs to cover a longer distance of the road to ensure driving safety. Therefore, the target illumination distance is expressed as a function of the vehicle speed v D(v).
  • the target illumination distance D(v) can be described as a piecewise function of the vehicle speed v:
  • the high-frequency vibration input from the road surface will cause the vehicle body to vibrate.
  • the measurement value of the vehicle height sensor will also produce high-frequency jitter, which will cause the jitter of the output angle of the ALS method. Due to the inevitable delay in the algorithm, the jitter of the vehicle body and the jitter of the headlight output angle are not synchronized. In this case, the ALS method needs to identify the rough road surface and shield the output of the ALS algorithm when the vehicle enters the rough road, that is, lock the output angle of the headlight at the current position.
  • the decision tree method in machine learning is used to identify road condition information.
  • the general process of machine learning includes four parts: feature selection and construction, data collection, processing and data set division, and model training and verification.
  • the decision tree used for road surface recognition is a classification problem, and its process is shown in Figure 11, which specifically includes:
  • Data collection, processing and data set division Drive the vehicle on various road conditions/operating conditions (as shown in the table below), record several groups of data (no less than ten groups) for each road condition/operating condition as a data set, and distinguish good roads from bad roads through the amplitude of the data returned by the vehicle height sensor. The part with obvious amplitude is the bad road, and the rest is the good road. All the collected data are divided into training set and test set at a ratio of about 4:1. It should be noted that the ratio of good roads to bad roads in the training set should be the same as the ratio of good roads to bad roads in the test set.
  • the ALS method can select all input data under the two-sensor solution.
  • the input data is processed here to extract six feature variables from each input data: original value, differential value, sliding window mean, sliding window standard deviation, sliding window maximum, and sliding window minimum.
  • original value differential value
  • sliding window mean sliding window standard deviation
  • sliding window maximum sliding window minimum.
  • t 0 represents the system sampling period.
  • the vehicle speed can be directly used as the first feature.
  • Sliding window mean Calculate the mean of the sequence consisting of the vehicle speed at time t, tt 0 , t-2t 0 , t-3t 0 , ... t-nt 0 , and use this mean as the third feature at time t.
  • Sliding window standard deviation Calculate the standard deviation of the sequence consisting of the vehicle speed at time t, time tt 0 , time t-2t 0 , time t-3t 0 , ... time t-nt 0 , and take this standard deviation as the fourth feature at time t.
  • Sliding window maximum value Find the maximum value of the sequence consisting of the vehicle speed at time t, time tt 0 , time t-2t 0 , time t-3t 0 , ... time t-nt 0 , and use this maximum value as the fifth feature at time t.
  • Sliding window minimum Find the minimum value of the sequence consisting of the vehicle speed at time t, time tt 0 , time t-2t 0 , time t-3t 0 , ... time t-nt 0 , and take this minimum value as the sixth feature at time t.
  • the above six features are extracted from the four input data respectively, and finally 24 features are obtained.
  • 24 feature values can be extracted according to the above method, and it is combined with the label (the sampling point corresponds to the quality of the road condition, 0 indicates bad road, 1 indicates good road) to form a vector containing 25 elements.
  • This vector is generated for each sampling point in the training set, and finally an m0 ⁇ 25 matrix is obtained ( m0 is the total number of sampling points in the training set).
  • This feature matrix can be used as the input of model training.
  • the decision tree training process is based on the decision tree toolkit provided by MATLAB.
  • Train_input is the matrix composed of the first 24 columns in the feature matrix
  • Train_Output is the 25th column vector in the feature matrix
  • the other parameters are default
  • the final Factor is the parameter of the entire model, which contains all the parameters of the model established according to the training data, from which an m 1 ⁇ 4 matrix can be finally extracted
  • m 1 is the total number of nodes in the decision tree.
  • This matrix contains all the information related to the decision tree, and thus the matrix can output a recognition result for any input feature vector (that is, the vector composed of the first 24 elements in a row in the feature matrix) - 1 (good path) or 0 (bad path).
  • the four columns of this matrix represent the feature index, split threshold, left child node index, and output result.
  • the input feature vector is shown in the following table:
  • the decision tree implementation process is as follows:
  • the first element is 3, which means that the third feature in the input feature vector needs to be compared, that is, 31;
  • the second element of the first row is 60, which means that 31 needs to be compared with 60, and the result is 31 ⁇ 60, which means that the decision tree should jump to the left child node;
  • the third element of the first row is 4, which means that the left child node is stored in the fourth row of the matrix. Therefore, the decision tree jumps to the fourth row and starts checking the elements of the fourth row of the decision tree matrix one by one;
  • the first element of the eighth row is 0, indicating that the node corresponding to the eighth row is a leaf node (i.e., the decision end point).
  • the fourth element 1 of the eighth row can be directly output, indicating that the vehicle is driving on a good road at the time when the feature vector corresponding to the sampling point in Table 4 is located.
  • this is the complete process of decision tree implementation. After the model training is completed, it is necessary to build the model in Simulink and perform simulation verification. Further optimization is performed based on the verification accuracy, and the value of the sliding window width n is repeatedly adjusted until the ideal recognition accuracy is achieved.
  • a supplementary strategy is added to the output of the decision tree model, that is, the proportion of the time of "good road” and “bad road” output by the model in the past period of time is counted. If the proportion of "good road” is higher, the current road surface is considered to be good, otherwise it is considered to be bad, thereby reducing the negative impact caused by the misidentification of a few points.
  • the detection window in the supplementary strategy also needs to be obtained through repeated experiments, and it is finally determined to be 75.
  • the ALS method described in the present invention is still applicable.
  • the vehicle headlight automatic leveling method provided by the present invention generates a control signal based on a vehicle body height change signal, has higher stability and robustness than an inertial measurement element solution, and can simultaneously provide three posture data of pitch angle, roll angle and vertical displacement for calculating the output angle; a threshold is set for the adjustment of the output angle through three working modes, and the stepper motor will only make an adjustment action when the cumulative change of the output angle exceeds the threshold, thereby avoiding frequent jitters of the output angle caused by the high-frequency vibration of the vehicle body and affecting the driver's field of vision; in addition, a machine learning method is used to identify rough roads and temporarily disable the adjustment function on rough roads, thereby further improving the stability of the headlight illumination range, and is used to adaptively adjust the headlight illumination direction vertically when the vehicle posture changes, so that its illumination range remains stable, avoiding the potential risk of traffic accidents caused by its illumination position being too high or too low.
  • the method of one or more embodiments of this specification can be performed by a single device.
  • the method of this embodiment can also be applied in a distributed scenario and completed by multiple devices cooperating with each other.
  • one of the multiple devices can only perform one or more steps of the method of one or more embodiments of this specification, and the multiple devices will interact with each other to complete the described method.
  • the present invention also provides a vehicle headlight automatic leveling device, the vehicle headlight automatic leveling device comprising:
  • a road condition information acquisition module wherein the road condition information acquisition module is used to acquire road condition information
  • a judgment module used to judge whether the current road surface is a rough road surface according to the road condition information
  • a vehicle height change signal acquisition module wherein the vehicle height change signal acquisition module is used to acquire vehicle height change signals of a plurality of preset positions when the judgment result of the judgment module is no;
  • a posture information acquisition module the posture information acquisition module is used to calculate the vehicle posture information according to the vehicle height change signals at the plurality of preset positions;
  • An initial aiming angle acquisition module wherein the initial aiming angle acquisition module is used to acquire an initial aiming angle
  • a headlamp angle information acquisition module wherein the headlamp angle information acquisition module is used to obtain the headlamp angle information according to the vehicle posture information and the initial irradiation point when the judgment result of the judgment module is no;
  • a headlight control signal acquisition module the headlight control signal acquisition module is used to generate a headlight control signal according to the headlight angle information
  • a sending module is used to send the headlight control signal to the headlight, so that the headlight performs light leveling according to the headlight control signal.
  • the apparatus of the above-mentioned embodiment is used to implement the corresponding method in the above-mentioned embodiment, and has the beneficial effects of the corresponding method embodiment, which will not be described in detail here.
  • FIG14 shows a more specific schematic diagram of the hardware structure of an electronic device provided in this embodiment, and the device may include: a processor 1010, a memory 1020, an input/output interface 1030, a communication interface 1040, and a bus 1050.
  • the processor 1010, the memory 1020, the input/output interface 1030, and the communication interface 1040 are connected to each other in communication within the device through the bus 1050.
  • the processor 1010 can be implemented by a general-purpose CPU (Central Processing Unit), a microprocessor, an application specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the vehicle headlight automatic leveling method provided in the embodiments of this specification.
  • a general-purpose CPU Central Processing Unit
  • ASIC application specific integrated circuit
  • the memory 1020 can be implemented in the form of ROM (Read Only Memory), RAM (Random Access Memory), static storage device, dynamic storage device, etc.
  • the memory 1020 can store an operating system and other application programs. When the technical solutions provided in the embodiments of this specification are implemented by software or firmware, the relevant program codes are stored in the memory 1020 and are called and executed by the processor 1010.
  • the input/output interface 1030 is used to connect the input/output module to realize information input and output.
  • the input/output module can be configured as a component in the device (not shown in the figure), or it can be externally connected to the device to provide corresponding functions.
  • the input device may include a keyboard, a mouse, a touch screen, Microphones, various sensors, etc.
  • Output devices can include displays, speakers, vibrators, indicator lights, etc.
  • the communication interface 1040 is used to connect a communication module (not shown) to realize communication interaction between the device and other devices.
  • the communication module can realize communication through a wired mode (such as USB, network cable, etc.) or a wireless mode (such as mobile network, WIFI, Bluetooth, etc.).
  • the bus 1050 includes a path that transmits information between the various components of the device (eg, the processor 1010, the memory 1020, the input/output interface 1030, and the communication interface 1040).
  • the above device only shows the processor 1010, the memory 1020, the input/output interface 1030, the communication interface 1040 and the bus 1050, in the specific implementation process, the device may also include other components necessary for normal operation.
  • the above device may also only include the components necessary for implementing the embodiments of the present specification, and does not necessarily include all the components shown in the figure.
  • An embodiment of the present invention provides a computer-readable storage medium, which stores a computer program.
  • the computer program is executed by a processor, the above-mentioned vehicle headlamp automatic leveling method can be implemented.
  • the computer-readable media of this embodiment include permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology.
  • the information can be computer-readable instructions, data structures, program modules or other data.
  • Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, read-only compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, Magnetic cartridges, magnetic tape, magnetic disk storage, or other magnetic storage devices, or any other non-transmission medium, may be used to store information that can be accessed by a computing device.
  • PRAM phase change memory
  • SRAM static random access memory
  • DRAM dynamic random access memory
  • RAM random access memory
  • ROM read-only memory
  • EEPROM electrically erasable
  • DRAM dynamic RAM

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Abstract

一种车辆前照灯自动调平方法包括：获取路况信息；根据路况信息判断当前路面是否为粗糙路面；若否，则获取多个预设位置的车身高度变化信号；根据多个预设位置的车身高度变化信号计算车辆位姿信息；获取初始照准角；根据车辆位姿信息和初始照准角获得前照灯转角信息；根据前照灯转角信息生成前照灯控制信号；将前照灯控制信号发送至前照灯，以使前照灯根据前照灯控制信号进行灯光调平。该方法基于车身高度变化信号生成控制信号，在车辆姿态变化时自适应地垂直调节前照灯的照射方向，使得其照射范围保持稳定，避免因其照射位置过高或过低而导致的交通事故潜在风险。还公开了一种车辆前照灯自动调平装置。

Description

一种车辆前照灯自动调平方法及装置 技术领域
本发明涉及车辆技术领域，尤其是涉及一种车辆前照灯自动调平方法及装置。
背景技术
在水平路面上，车辆负载变化、车速变化、车辆转弯等因素均可能导致车身姿态变化，进而导致前照灯照射方向随车身晃动的情况。这种现象既可能导致原本需要被照射到的地方出现视野盲区，同时也会引起驾驶员的视觉疲劳。
现有研究中，研究人员通过对前照灯进行适当的调节使得前照灯的照射范围更稳定。
现有技术中有一种前照灯自适应调节系统，该系统在左右前照灯处各自安装了一个惯性测量单元和一个处理器，惯性测量单元用于测量加速度和角速度并推算出车身的姿态，随后将推算出的姿态发送至对应的处理器。处理器根据外部输入的车速信号确定车辆是否处于静止状态，若车辆处于静止状态，则认为惯性测量单元测得的加速度为重力加速度，根据其与惯性测量单元的相对方向可以确定车身此时的姿态，处理器根据此时的姿态向与前照灯相连的步进电机发送相应指令，步进电机垂直转动使得前照灯照射方向符合法规要求；若车辆处于运动状态，则惯性测量单元测量车辆的加速度用于判断车辆是否处于加速/刹车工况下，处理器根据这一信息向步进电机发送指令，控制前照灯垂直转动以抵消车辆加减速导致的前照灯照射方向变化。
以上方案对于惯性测量单元测量得到的加速度具有很高的依赖性，然而惯性测量单元测量得到的加速度通常具有较高的噪声，可能会影响步进电机输出的精确度；除此以外，当车辆行驶在粗糙路面上时，路面的频繁抖动会导致惯性测量单元的测量结果大幅度频繁变化，使得步进电机位置变得不稳 定，从而导致系统不但无法起到安全照明的效果，反而会引起驾驶员和对向车驾驶员的视觉不适。
发明内容
本发明的目的是提供一种车辆前照灯自动调平方法，通过车辆状态和路面状态的实时估计，获取左侧前照灯和右侧前照灯的步进电机的转动角度，实现前照灯自动调平功能。
本发明提供了一种车辆前照灯自动调平方法，包括：
获取路况信息；
根据所述路况信息判断当前路面是否为粗糙路面；若否，则
获取多个预设位置的车身高度变化信号；
根据所述多个预设位置的车身高度变化信号计算车辆位姿信息；
获取初始照准角；
根据所述车辆位姿信息和初始照准角获得前照灯转角信息；
根据所述前照灯转角信息生成前照灯控制信号；
将所述前照灯控制信号发送至前照灯，以使前照灯根据所述前照灯控制信号进行灯光调平。
可选地，所述车辆前照灯自动调平方法还包括：
根据所述路况信息判断当前路面是否为粗糙路面；若是，则
生成锁止前照灯角度的控制信号；
将所述锁止前照灯角度的控制信号发送至前照灯；
以使前照灯根据所述前照灯控制信号锁止灯光角度。
可选地，所述多个预设位置的车身高度变化信号包括：左前车身高度的相对变化量、左后车身高度的相对变化量、右前车身高度的相对变化量、右后车身高度的相对变化量；
根据所述多个预设位置的车身高度变化信号计算车辆位姿信息包括：
获取左前的车身高度传感器和左后的车身高度传感器之间的距离、左前的车身高度传感器和右前的车身高度传感器之间的距离；
根据所述左前车身高度的相对变化量、左后车身高度的相对变化量、右 前车身高度的相对变化量、右后车身高度的相对变化量、左前的车身高度传感器和左后的车身高度传感器之间的距离、左前的车身高度传感器和右前的车身高度传感器之间的距离计算车辆位姿信息。
可选地，所述根据所述车辆位姿信息和初始照准角获得前照灯转角信息包括：
获取左侧前照灯与前轴的距离在车辆簧上质量坐标系X轴上的投影，左侧前照灯与右侧前照灯之间的距离，轴距，目标照射距离，车辆重心距地面高度；
根据所述车辆位姿信息、初始照射准角、左侧前照灯与前轴的距离在车辆簧上质量坐标系X轴上的投影，左侧前照灯与右侧前照灯之间的距离，轴距，目标照射距离，车辆重心距地面高度计算前照灯转角信息。
可选地，所述多个预设位置的车身高度变化信号包括：左前车身高度的相对变化量，左后车身高度的相对变化量；
根据所述多个预设位置的车身高度变化信号计算车辆位姿信息包括：
获取左前的车身高度传感器和左后的车身高度传感器之间的距离；
根据所述左前车身高度的相对变化量、左后车身高度的相对变化量、左前的车身高度传感器和左后的车身高度传感器之间的距离计算车辆位姿信息。
可选地，所述根据所述车辆位姿信息和初始照准角获得前照灯转角信息包括：
获取前照灯安装高度、左侧前照灯与前轴的距离在车辆簧上质量坐标系X轴上的投影、轴距、目标照射距离、车辆重心距地面高度；
根据所述车辆位姿信息、初始照准角、前照灯安装高度、左侧前照灯与前轴的距离在车辆簧上质量坐标系X轴上的投影、轴距、目标照射距离、车辆重心距地面高度计算前照灯转角信息。
可选地，所述获取目标照射距离包括：
获取前照灯安装高度和车速；
根据前照灯高度和车速获取目标照射距离。
可选地，所述根据所述前照灯转角信息生成前照灯控制信号包括：
获取输出转角的下限、输出转角的上限、防抖阈值、控制周期、上一时 刻的步进电机的输出转角、限幅函数、当前时刻的输出转角缩放值；
根据输出转角的下限、输出转角的上限、防抖阈值、控制周期、上一时刻的步进电机的输出转角、限幅函数、当前时刻的输出转角缩放值生成前照灯控制信号。
可选地，获取当前时刻的输出转角缩放值包括：
获取缩放系数、左侧前照灯输出转角和/或右侧前照灯输出转角；
根据所述缩放系数、左侧前照灯输出转角和/或右侧前照灯输出转角计算当前时刻的输出转角缩放值。
在另一方面，本发明提供了一种车辆前照灯自动调平装置，所述车辆前照灯自动调平装置包括：
路况信息获取模块，所述路况信息获取模块用于获取路况信息；
判断模块，所述用于根据所述路况信息判断当前路面是否为粗糙路面；
车身高度变化信号获取模块，所述车身高度变化信号获取模块用于在所述判断模块的判断结果为否时，获取多个预设位置的车身高度变化信号；
位姿信息获取模块，所述位姿信息获取模块用于根据所述多个预设位置的车身高度变化信号计算车辆位姿信息；
初始照准角获取模块，所述初始照准角获取模块用于获取初始照准角；
前照灯转角信息获取模块，所述前照灯转角信息获取模块用于在所述判断模块的判断结果为否时，根据所述车辆位姿信息和初始照射准点获得前照灯转角信息；
前照灯控制信号获取模块，所述前照灯控制信号获取模块用于根据所述前照灯转角信息生成前照灯控制信号；
发送模块，所述发送模块用于将所述前照灯控制信号发送至前照灯，以使前照灯根据所述前照灯控制信号进行灯光调平。
本发明所述的有益效果：
本发明提供的车辆前照灯自动调平方法基于车身高度变化信号生成控制信号，相比惯性测量元件方案而言具有更高的稳定性和鲁棒性，并能够同时提供俯仰角、滚转角和垂向位移三个姿态数据用于输出转角的计算，在车辆姿态变化时自适应地垂直调节前照灯的照射方向，使得其照射范围保持稳定， 避免因其照射位置过高或过低而导致的交通事故潜在风险。
附图说明
图1为本发明所述明暗截止线位置与照射距离的关系示意图。
图2为本发明所述车辆前照灯自动调平方法流程示意图。
图3为本发明所述车身姿态变化示意图。
图4为本发明所述输出转角计算示意图。
图5为本发明所述使用ALS方法后车辆加速过程中的车辆状态示意图。
图6为本发明所述使用ALS方法后车辆开始刹车时刻的车辆状态示意图。
图7为本发明所述使用ALS方法后车辆完全停止时刻的车辆状态示意图。
图8为本发明所述无ALS方法情况下车辆加速过程中的车辆状态示意图。
图9为本发明所述无ALS方法情况下车辆开始刹车时刻的车辆状态示意图。
图10为本发明所述无ALS方法情况下车辆完全停止时刻的车辆状态示意图。
图11为本发明所述路面识别流程图。
图12为本发明所述决策树流程图。
图13是本发明所述的车辆前照灯自动调平方法的流程示意图。
图14是用于实现本发明提供的车辆前照灯自动调平方法的电子设备的示意图。
具体实施方式
下面结合对本发明做进一步的详细说明，以令本领域技术人员参照说明书文字能够据以实施。
图13是本发明一实施例的车辆前照灯自动调平方法的流程示意图。
参照图13，本发明提供了一种车辆前照灯自动调平方法，包括：
获取路况信息；
根据路况信息判断当前路面是否为粗糙路面；若否，则
获取多个预设位置的车身高度变化信号；
根据预设位置的车身高度变化信号计算车辆位姿信息；
获取初始照准角；
根据车辆位姿信息和初始照准角获得前照灯转角信息；
根据前照灯转角信息生成前照灯控制信号；
将所述前照灯控制信号发送至前照灯，以使前照灯根据前照灯控制信号进行灯光调平。
本发明提供的车辆前照灯自动调平方法基于车身高度变化信号生成控制信号，相比惯性测量元件方案而言具有更高的稳定性和鲁棒性，并能够同时提供俯仰角、滚转角和垂向位移三个姿态数据用于输出转角的计算，在车辆姿态变化时自适应地垂直调节前照灯的照射方向，使得其照射范围保持稳定，避免因其照射位置过高或过低而导致的交通事故潜在风险。
在一实施例中，车辆前照灯自动调平方法还包括：
根据所述路况信息判断当前路面是否为粗糙路面；若是，则
生成锁止前照灯角度的控制信号；
将所述锁止前照灯角度的控制信号发送至前照灯；
以使前照灯根据所述前照灯控制信号锁止灯光角度。
在一实施例中，多个预设位置的车身高度变化信号包括：左前车身高度的相对变化量、左后车身高度的相对变化量、右前车身高度的相对变化量、右后车身高度的相对变化量；
根据多个预设位置的车身高度变化信号计算车辆位姿信息包括：
获取左前的车身高度传感器和左后的车身高度传感器之间的距离、左前的车身高度传感器和右前的车身高度传感器之间的距离；
根据左前车身高度的相对变化量、左后车身高度的相对变化量、右前车身高度的相对变化量、右后车身高度的相对变化量、左前的车身高度传感器和左后的车身高度传感器之间的距离、左前的车身高度传感器和右前的车身高度传感器之间的距离计算车辆位姿信息。
具体而言，按照如下公式计算车辆位姿信息：


式中，θ为车辆簧上质量相对车辆簧下质量的俯仰角，Zfl为左前车身高度的相对变化量，Zrl为左后车身高度的相对变化量，Zfr为右前车身高度的相对变化量，Zrr为右后车身高度的相对变化量，γ为车辆簧上质量相对车辆簧下质量的滚转角，Δz为车辆簧上质量相对车辆簧下质量的z轴位移，L0为左前的车身高度传感器和左后的车身高度传感器之间的距离，W0为左前的车身高度传感器和右前的车身高度传感器之间的距离。
车辆位姿信息包括：车辆簧上质量相对车辆簧下质量的俯仰角，车辆簧上质量相对车辆簧下质量的滚转角和车辆簧上质量相对车辆簧下质量的z轴位移。
在一实施例中，根据车辆位姿信息和初始照准角获得前照灯转角信息包括：
获取左侧前照灯与前轴的距离在车辆簧上质量坐标系X轴上的投影，左侧前照灯与右侧前照灯之间的距离，轴距，目标照射距离，车辆重心距地面高度；
根据车辆位姿信息、初始照射准角、左侧前照灯与前轴的距离在车辆簧上质量坐标系X轴上的投影，左侧前照灯与右侧前照灯之间的距离，轴距，目标照射距离，车辆重心距地面高度计算前照灯转角信息。
具体而言，按照如下公式计算前照灯转角信息：

式中，αLout为左侧前照灯的输出转角，L1为左侧前照灯与前轴的距离在车辆簧上质量坐标系X轴上的投影，W1为左侧前照灯与右侧前照灯之间的距离，L为轴距，D(v)为目标照射距离，α0为初始照准角，H为车辆重心距地面高度，αRout为右侧前照灯的输出转角。
可以知道的是，左侧前照灯的输出转角和右侧前照灯的输出转角均取向下为正。
在一实施例中，多个预设位置的车身高度变化信号包括：左前车身高度的相对变化量，左后车身高度的相对变化量；
根据多个预设位置的车身高度变化信号计算车辆位姿信息包括：
获取左前的车身高度传感器和左后的车身高度传感器之间的距离；
根据左前车身高度的相对变化量、左后车身高度的相对变化量、左前的车身高度传感器和左后的车身高度传感器之间的距离计算车辆位姿信息。
具体而言，按照如下公式计算车辆位姿信息：

γ＝0
式中，θ为车辆簧上质量相对车辆簧下质量的俯仰角，Zf为左前车身高度的相对变化量，Zr为左后车身高度的相对变化量，γ为车辆簧上质量相对车辆簧下质量的滚转角，Δz为车辆簧上质量相对车辆簧下质量的z轴位移，L0为左前的车身高度传感器和左后的车身高度传感器之间的距离。
在一实施例中，根据车辆位姿信息和初始照准角获得前照灯转角信息包括：
获取前照灯安装高度、左侧前照灯与前轴的距离在车辆簧上质量坐标系X轴上的投影、轴距、目标照射距离、车辆重心距地面高度；
根据车辆位姿信息、初始照准角、前照灯安装高度、左侧前照灯与前轴 的距离在车辆簧上质量坐标系X轴上的投影、轴距、目标照射距离、车辆重心距地面高度计算前照灯转角信息。
具体而言，按照如下公式计算前照灯转角信息：
式中，αout为前照灯的输出转角，H0为前照灯安装高度，L1为左侧前照灯与前轴的距离在车辆簧上质量坐标系X轴上的投影，L为轴距，D(v)为目标照射距离，H为车辆重心距地面高度，α0为初始照准角。
在本实施例中，前照灯的输出转角取向下为正；左前照灯和右前照灯输出转角相同。
在一实施例中，获取目标照射距离包括：
获取前照灯安装高度和车速；
根据前照灯高度和车速获取目标照射距离。
具体而言，按照如下公式计算目标照射距离：
式中，H0为前照灯安装高度，v为车速。
在一实施例中，根据前照灯转角信息生成前照灯控制信号包括：
获取输出转角的下限、输出转角的上限、防抖阈值、控制周期、上一时刻的步进电机的输出转角、限幅函数、当前时刻的输出转角缩放值；
根据输出转角的下限、输出转角的上限、防抖阈值、控制周期、上一时刻的步进电机的输出转角、限幅函数、当前时刻的输出转角缩放值生成前照灯控制信号。
具体而言，按照如下公式计算车辆前照灯的步进电机的输出转角：

式中，αfout(t)为t时刻(当前时刻)的步进电机的输出转角，αmin为输出转角的下限，αmax为输出转角的上限，αthres为防抖阈值，t0为控制周期，αfout(t-t0)为t-t0时刻的步进电机的输出转角，f(αout-1(t))为限幅函数，αout-1(t)为t时刻的输出转角缩放值。
在一实施例中，
获取当前时刻(t时刻)的输出转角缩放值包括：
获取缩放系数、左侧前照灯输出转角和/或右侧前照灯输出转角；
根据缩放系数、左侧前照灯输出转角和/或右侧前照灯输出转角计算当前
时刻的输出转角缩放值。具体而言，按照如下公式计算t时刻的输出转角
缩放值：
αout-1(t)＝kaα(i)
式中，ka为缩放系数，α(i)为左侧前照灯输出转角和/或右侧前照灯输出转角。
下面以一具体的实施例对本发明提供的一种车辆前照灯自动调平方法进行详细的阐述，值得注意的是，本实施例并不是对本发明的限制。
本发明提供一种车辆前照灯自动调平(ALS，Automotive Headlamp Leveling System)方法，考虑了车辆在水平平整路面、粗糙路面、斜坡上、两段坡度不同的路面之间过渡及驶过减速带或较大坑洼下行驶的情况对于车辆前照灯的近光灯下的自动调平。
水平路面指路面平坦、没有凹凸起伏、路面所在平面与重力方向垂直的路面，在水平路面上，如图1所示，由明暗截止线的定义容易想到，既然前照灯发出的光能够在前方一定距离内的垂直屏幕上产生明暗陡变的分界线，那么其也应当能在前方的水平路面上产生某一明暗分界线，下面将地面上的 明暗分界线与前照灯的距离在地面上的投影称为前照灯的“照射距离”，记为D，根据前照灯在配光屏幕上明暗截止线的位置，可以推算出其在前方水平路面上的照射距离：
式中，H0为前照灯安装高度；α0为初始照准角，也称初始下倾角，取向下为正，在配光测试中，α0的值可通过下式计算：
在近光灯的配光测试中，D0为前照灯与配光屏幕间的距离，D0取10m，h0为明暗截止线的高度，H0-h0值取0.1m；实际车辆上由于近光灯的安装情况不同，α0的值也不完全相同。GB4785规定，近光灯的初始照准应在-1.0％～-1.5％之间，即0.57°＜α0＜0.86°。
将位于左、右侧前照灯正前方且位于地面上的明暗分界线上的点称为左、右车灯的照准点，可以认为前照灯与其照准点之间的区域均在前照灯的有效照明范围之内，因此，“使前照灯照射范围保持稳定”可以等价描述为“使左、右车灯的照准点位置保持稳定”。
以车辆的簧下质量为参考建立坐标系，前轮轴中心与后轮轴中心连线方向为x轴方向(指向车辆前方)，轮轴方向为y轴方向(指向车辆左侧)，垂直于xy平面的方向为z轴方向(指向车辆上方)；以车辆的簧上质量为参考建立坐标系，车辆底盘的对称轴方向为x轴方向(指向车辆前方)，垂直于底盘方向为z轴方向(指向车辆上方)，垂直于xz平面的方向为y轴方向(指向车辆左侧)。当车辆静止在水平路面上、处于额定负载下时(额定状态)，选择车辆重心作为两个坐标系共同的原点，则两个坐标系完全重合，将此时左、右车灯的照准点称为初始照准点，将其在簧下质量坐标系中的坐标分别记为LA0＝[xL0,yL0,zL0]，RA0＝[xR0,yR0,zR0]。当车辆在水平路面行驶时，如果忽略轮胎的形变量，则簧下质量坐标系的xy平面始终平行于惯性系的xy平面，而簧上质量坐标系相对簧下质量坐标系的位姿则会随着负载、车速等的变化而发生改变。由于前照灯与簧上质量固连，其在簧下质量坐标系中的坐标和 照射方向也会随之变化，从而其照准点位置也会变化。为了尽可能地“抵消”这一变化，需要向左前照灯和右前照灯分别输出一个转角αLout、αRout，将此时左、右车灯的照准点在簧下质量坐标系中的坐标分别记为LA＝[xL,yL,zL]，RA＝[xR,yR,zR]，则前照灯照准点位置保持稳定的条件是：
即左、右车灯的照准点在簧下质量坐标系中的坐标恒定不变。
显然，LA是簧上质量相对簧下质量的位姿A和ALS方法输出的左侧前照灯转角αLout的函数，RA是簧上质量相对簧下质量的位姿A和ALS方法输出的右侧前照灯转角αRout的函数，从而上式可改写为：
式(1-4)即为本发明所述车辆前照灯自动调平方法要实现的目标。
为了以式(1-4)推导出ALS方法中输出转角的计算公式，需要解决两个问题：
一、获取车辆簧上质量相对簧下质量的位姿A：
目前获取簧上质量位姿的方案有三种，分别适用于三种安装了不同传感器的车型：(1)配置四个车身高度传感器，安装四个车轮附近，通过CAN总线获取信息；(2)配置两个车身高度传感器，分别安装在左前、左后车轮附近，通过AD模块直接采集信息；(3)配置陀螺仪，直接获取车身的姿态角。
如图2所示，对于四个车身高度传感器和两个车身高度传感器需要将传感器测得的原始数据转化为可用的、高质量的ALS方法输入信号。
对于四个车身高度传感器方案而言，其传感器测量信号无需进行滤波，只需将其进行量纲转化、与零点相减后即可作为ALS方法的输入。
对于两个车身高度传感器，其传感器测量信号需要经过转换，由传感器输出电压与输入角度之间的线性关系获得车身高度传感器测得的簧上簧下相对高度与输出电压之间的线性关系，将某一状态下某一传感器对应的簧上簧下相对高度的值与其零点相减，即可得到该状态下的左前或左后车轮传感器测得的相对高度变化量Zf或Zr，作为ALS方法的输入。
车身高度传感器输出数字信号带有噪声，需要对其进行滤波处理。
对车辆行驶的静态部分和动态部分分别进行滤波处理后，确定选择窗口宽度为10的滑窗均值滤波对AD信号进行平滑滤波处理。
其中，当车辆处于额定状态下时车身高度传感器测量得的高度值称为传感器的零点。
车身姿态变化时，车灯的照准点应当始终维持在初始照准点处，即车辆处于额定状态下的照准点处，因此簧上质量的姿态也应当以额定状态下的姿态为参考基准，记此状态下四个车身高度传感器的测量值分别为Z0_fl,Z0_fr,Z0_rl,Z0_rr(fl:左前，fr:右前，rl:左后，rr:右后)，将这四个数值称为四个车身高度传感器的“零点”。当簧上质量位姿变化到某一状态时，四个车身高度传感器的测量值也相应变化，记四个传感器测量值相对其各自零点的变化量分别为Zfl、Zfr、Zrl、Zrr，如图3所示(图中虚线框对应簧上质量在额定状态下的初始姿态，实线框对应其变化后的姿态，每个线框的四个顶点分别对应四个传感器与簧上质量的连接点)，将这四个测量值变化量作为ASL方法的输入，对簧上质量和簧下质量的相对位姿进行估计。
三维空间中两个坐标系之间的相对位姿可以通过六个参数描述：三个方向上的欧拉角(俯仰角-θ-绕Y轴旋转，滚转角-γ-绕X轴旋转，偏航角--绕Z轴旋转)和三个维度上的相对位移Δx、Δy、Δz，使用Zfl、Zfr、Zrl、Zrr四个值解算出以上六个参数是不可能的，对问题进行简化，当车辆在水平路面行驶时，簧上质量相对簧下质量坐标系的偏航角x轴位移Δx和y轴位移Δy均可以忽略不计，可以认为两坐标系间仅存在俯仰运动θ、滚转运动γ和z轴方向上的运动Δz，由簧下质量坐标系到簧上质量坐标系的变化顺序为θ-γ-Δz(均以簧下质量坐标系为参考)。
额定状态下，记四个车身高度传感器与簧上质量的连接点坐标(即图3中虚线框的四个顶点坐标)分别为P0_fl、P0_fr、P0_rl、P0_rr，P0_fl、P0_fr之间的距离在y轴上的投影为W0(左前车身高度传感器与右前车身高度传感器之间的距离)，P0_fl、P0_rl之间的距离在x轴上的投影为L0(左前车身高度传感器与左后车身高度传感器之间的距离)，P0_fl、P0_fr、P0_rl、P0_rr相对车辆重心的高度为zc(忽略四个传感器对应的zc之间的微小差距)，可得以上四个 点的坐标分别为
对四个点的坐标依次进行θ-γ-Δz三个方向上的旋转/平移变换，得到姿态变化后的四个传感器与簧上质量的连接点坐标Pfl、Pfr、Prl、Prr(即图3中实线框的四个顶点坐标)：

式中，RX为簧上质量绕X轴的旋转变换矩阵，RY为簧上质量绕Y轴的旋转变换矩阵，γ为簧上质量相对簧下质量的滚转角，θ为簧上质量相对簧下质量的俯仰角、Δz分别表示簧上质量相对簧下质量的z轴位移；Pfl、Pfr、Prl、Prr四个点的X轴、Y轴坐标不参与后续计算，式中用xfl、yfl等符号代替。由图3可以看出，Pfl与P0_fl的Z轴坐标之差即为Zfl的值，对于Zfr、Zrl、Zrr同理，即：
考虑到γ和θ的值较小(通常在±2°以内)，从简化运算的角度考虑，对上式中的三角函数泰勒展开并忽略二次及以上项，即令sinθ＝θ，sinγ＝γ，cosθ＝cosγ＝1，则上式简化为：
将式(2-4)中四个等式相加，得到：
将式(2-4)中第一、第二个等式相减，第三、第四个等式相减，得到：
从减小误差的角度考虑，式(2-6)可改写为：
将式(2-4)中第一、第三个等式相减，第二、第四个等式相减，得到：
从减小误差的角度考虑，式(2-8)可改写为：
式(2-5)、(2-7)、(2-9)即为基于四车身高度传感器的簧上质量位姿估计方法：
其中，俯仰角θ以抬头为正，滚转角γ以左高右低为正。
通过veDYNA进行仿真验证，仿真结果表明，本发明提出的基于车身高度传感器的俯仰角、滚转角、z轴位移估计方法(式2-10)具有较高可靠性。
两传感器的配置可视为四个传感器的特殊情况，即两传感器输入下的左前传感器测量值可以同时视为四传感器输入下的左前传感器和右前传感器测量值，而两传感器输入下的左后传感器测量值可以同时视为四传感器输入下的左后传感器和右后传感器测量值，即：
式中，Zf为左前车辆高度传感器的相对高度变化量，Zr为左后车辆高度传感器的相对高度变化量；
将式(2-11)代入式(2-10)得到两传感器输入下的位姿估计公式：
二、由车辆簧上质量相对簧下质量的位姿A和初始照准点LA0、RA0推导车辆的前照灯转角αLout和αRout：
以簧上质量坐标系为参考，以左侧前照灯为例，如图4所示，当车辆静止且处于额定载荷下时，簧上质量坐标系和簧下质量坐标系完全重合，记前照灯与前轴的距离在x轴上的投影为L1，左右前照灯间距为W1，车辆重心距地面高度为H，前照灯距地面高度为H0，可以得到左侧前照灯初始位置PL0的坐标(假定车辆重心到车辆前、后轮轴的距离相等)：
已知前照灯初始照准角α0，可得左侧前照灯初始照准点PLA0的坐标：
当车身姿态发生变化时，簧上质量坐标系相对簧下质量坐标系产生旋转平移变换，变换顺序为θ-γ-Δz(均以簧下质量坐标系为参考)。由于左侧前照灯与簧上质量坐标系固连，其在簧上质量坐标系下的坐标不变，仍为PL0；左侧前照灯的初始照准点PLA0(即姿态变化后的期望照准点)在簧下质量坐标系中的坐标不变，从而其在簧上质量坐标系中的坐标PLA，由z轴方向上的平移变换和XY欧拉角逆变换求得：
式(3-3)中，RX为车辆绕X轴的旋转变换矩阵，RY为车辆绕Y轴的旋转变换矩阵，γ为簧上质量相对簧下质量的滚转角，θ为簧上质量相对簧下质量的俯仰角，Δz为簧上质量相对簧下质量的z轴位移。按照前文描述，左侧前 照灯此时的照准方向向量应当由L0点指向LA点，即
本发明的目的是将左侧前照灯的照准方向由初始方向(与xz平面夹角为0，与x轴夹角为α0)调整至所需方向左侧前照灯照准方向有两个转动自由度，分别为在xz平面内旋转(即上下旋转)和在xy平面内旋转(即左右旋转)。理论上，前照灯需要通过在这两个自由度上的转动将其照准方向调整至方向；但实际上，计算结果表明，Lx和Lz的数量级相同，而Ly的值仅为前两者的0.01％左右。因此，可以认为前照灯无需进行左右旋转调整，仅需上下旋转即可达到目标，最终得到的左侧前照灯照射方向与x轴的夹角(即前照灯向下偏转角)为
从而左侧前照灯需要输出的垂直调整转角为初始垂直转角与所需垂直转角之差，即：
αLout取向下为正。
式(3-1)(3-2)(3-3)(3-4)(3-5)(3-6)即为平整水平路面上左侧前照灯自动调平算法的全部内容。
所有计算公式中，γ、θ、Δz的值由前述估计公式给出，其余参数均可查得。
将上述6个等式联立并将矩阵运算展开，可使用四传感器测量值变化量Zfl、Zrl、Zfr、Zrr计算左前照灯输出转角αLout的算法：
实际上，左右前照灯的输出转角计算方法基本相同，计算右侧前照灯输出转角αRout时仅需要将第一步中L0和LA0两点的y轴坐标改为其相反数即可，即
对于两车身高度传感器方案，左右侧输出转角相等，将其记为αout，则有：
式中，H0为前照灯安装高度，L1为左侧前照灯与前轴的距离在车辆簧上质量坐标系X轴上的投影，L为轴距，D(v)为目标照射距离，H为车辆重心距地面高度，α0为初始照准角，且前照灯的输出转角取向下为正；
对输出转角进行MATLAB仿真，固定Δz的值为0，在0～2°范围内调整γ和θ的值，按照上述算法获得左侧前照灯输出转角与输入俯仰角和滚转角之间均近似为正比例关系，固定γ和θ的值为0，在±0.25m范围内调整Δz的值，左侧前照灯输出转角与Δz也近似成正比例关系。
如图5、6、7所示，使用veDYNA对车辆从静止开始加速一段时间(期间经历四次挡位变化)后急刹车至停止的过程进行仿真，截取车辆加速过程中、开始刹车、完全停止三个时刻，记录行驶过程中位移、速度、加速度和俯仰角作为车辆的实时运动状况，记录使用车身高度传感器测量高度值作为输入，计算车身的俯仰姿态和垂直位移，一方面体现在顶部动画中的车身位姿变化中，另一方面作为ALS方法的输入，计算出对应的前照灯实时输出转角和前照灯在配光屏幕上的明暗截止线高度随时间变化曲线，作为ALS性能指标的验证，图中最上方为反映车辆与灯光运动状况的动画，其中标示有灯光照射范围，区域上边缘为明暗截止线，右边线为假想中的配光屏幕，始终在车灯前方10m处，车体与灯光均会随簧上质量的俯仰角和z轴位移变化而运动，但可以看出由于ALS算法的作用使得明暗截止线在假想配光屏幕上的位置几乎不变，ALS方法输出的车灯转角与输入的俯仰角接近，由于ALS的作用使得明暗截止线的高度变化量绝对值最大不超过3cm，在绝大多数时间内不超过1cm。
为了更明显地看出ALS方法的调整效果，使用与图5、6、7相同的程序、模型和仿真数据，将ALS的输出转角置为0，观察车灯的照射效果：如图8、9、10中三张图对应的情形与图5、6、7相同，可以看出车灯产生的明暗截止线在假想配光屏幕上的位置变化量随着车身俯仰而明显变化，从第三张图左下方的曲线可以看出明暗截止线高度变化量最高可达30cm。
三、从车灯的输出转角计算出与车灯相连的步进电机的输出步数，从而带动步进电机转动至目标位置从而完成ALS功能：
由式(2-10)和式(2-12)中的位姿估计公式成立的前提是车身高度传感器的工作平面垂直于地面，即传感器的“伸缩方向”垂直于地面，若传感器的“伸缩方向”与地面间存在夹角则zfl等测量值在输入算法前需要乘以一个系数从而计算得的姿态角也应当乘以由于ALS输入位姿与输出转角之间的近似线性关系，输出转角相比原计算值也需要乘以由于车身参数、传感器参数的测量误差对输出转角的影响均为近似线性，从而各个误差叠加后对输出转角的影响也为近似线性，相当于在输出转角上再乘以一个系数ke，即只需要将其整合为一个缩放系数即可，因此对输出转角应当进行适当的线性缩放：
式中，ka为缩放系数，α(i)为四个车身高度传感器时左侧前照灯输出转角或右侧前照灯输出转角；
由于两传感器方案和四传感器方案下的各个车身参数均可能存在差异，传感器的种类和测量原理也不同，因此需要为两种方案各自标定一个适当的kα。
标定kα时，首先将kα置为1，在黑暗环境中将额定负载下的实验车停在距离配光屏幕10m处，并在墙上标记此时明暗截止线的位置。进行加载试验。为了保证更好的观察效果，建议在后备箱加较大的载重以增大前照灯输出转角，但不宜过大，否则会超出ALS调整限幅；以在后备箱加300kg左右负重为宜。加载后观察配光屏幕上的明暗截止线位置，若其位置相比标记偏高，则需增大kα的值；若其位置相比标记偏低，则需减小kα的值。反复调整直至 明暗截止线与标记重合为止。
本实施例中使用的步进电机转角步距角为0.00158°，零位、上限位和下限位对应的位置编码分别为3288，4863和0，从而得到电机输出转角极限值为向上2.49°，向下5.19°，结合国标规定，得到输出转角的下限和上限分别为αmin＝max(0.29°-α0,-2.49°)，αmax＝min(1.43°-α0,5.19°)(向下为正)，由于α0的范围同样受到法规限制(-1.0％～-1.5％，即0.57°～0.85°)，经计算可得在法规限制下输出转角不可能达到电机的物理限位，从而可得αmin＝0.29°-α0，αmax＝1.43°-α0，根据车辆的实际情况，将αmax的表达式调整为αmax＝1.43°-α0+αb，其中αb为一个可标定的变量，其标定方法为：首先将αb的值设为0，在车辆上进行极限加载，若其照准点无法回调法规允许范围内，则小幅增大该参数的值，重复以上过程直至前照灯在极限加载下能够通过ALS的调节回到法规允许的范围之内，则将此时αb的值作为最终结果。
在车辆行驶过程中，由于路面输入变化、车辆加减速、传感器噪声等因素的影响，ALS算法得到的输出转角可能会频繁变化；若将未经处理的输出转角作为步进电机控制模块的输入，则会导致前照灯的频繁抖动，进而影响驾驶员的视觉体验乃至车辆的行驶安全，在对传感器信号进行滤波的基础上，还需要对输出转角进行防抖处理，即对输出转角的变化量设定阈值αthres以限制前照灯的抖动，若输出转角的变化量小于这一阈值则输入至步进电机控制模块的转角保持不变，则最终用于计算电机目标位置的前照灯输出转角αfout(t)关于αout(t)的函数为：
式中，αfout(t)为t时刻的步进电机的输出转角，αmin为输出转角的下限，αmax为输出转角的上限，αthres为防抖阈值，t0为控制周期，αfout(t-t0)为t-t0时刻的步进电机的输出转角，f(αout-1(t))为限幅函数，限幅函数满足：
由所述步进电机的输出转角确定调节步进电机的目标位置。
ALS方法输出转角的性能指标可以从三个方面考虑：响应速度，跟随精度，平稳性(即防抖能力)，这三个性能指标受到防抖阈值αthres和滤波窗口宽度n两方面影响。随着αthres的增大，ALS的跟随精度下降，平稳性提高；随着n的增大，ALS的响应速度下降，平稳性提高。
将车辆行驶状态分为三种：静止状态、急加速/急减速状态和车速缓慢变化状态，这三种行驶状态分别对应ALS的三种不同工作模式：静态模式、动态模式和车速跟随模式：
(1)静态模式：当车辆静止时，ALS系统工作于静态模式，此时导致车灯转角变化的主要因素是负载的变化，在静态模式下，αthres的值较小，用于提高跟随精度；n的值较大，用于提高平稳性。车辆进入静态模式的条件为：1)起动状态为Running(发动机车型)或整车Ready(电动车型)；2)车辆处于静止状态；3)初始化已经完成；4)近光灯已经打开；
(2)动态模式：当车辆急加速/急减速时，ALS系统工作于动态模式，此时导致车灯转角变化的主要因素是急加速/急减速带来的车身俯仰运动，在动态模式下，n的值较小，用于保证足够的跟随速度；αthres的值较小，用于提高跟随精度。车辆进入动态模式的条件为：a)起动状态为Running(发动机车型)或整车Ready(电动车型)；b)车辆处于运动状态；c)档位为前进档；d)初始化已经完成；e)近光灯已经打开；f)系统判断当前工况为急加速或急减速；g)车身高度传感器信号有变化；h)ALS控制器已完成初始化；
(3)车速跟随模式：当车辆平稳行驶、具有一定车速且加速度很小时，ALS系统工作于车速跟随模式，此时导致车灯转角变化的主要因素是车速的缓慢变化带来的目标照射距离变化，在车速跟随模式下，n的值较大，αthres的值也较大，两者都是为了防止输出转角的频繁抖动。车辆进入车速跟随模式的条件为：1)起动状态为Running(发动机车型)或整车Ready(电动车型)；2)车辆处于运动状态；3)档位为前进档；4)初始化已经完成；5)近光灯已经打开；6)系统判断当前工况为车速缓慢变化工况；7)ALS控制器已完成初始化。
其中，防抖阈值和滤波窗口宽度均根据车型的不同和车身高度传感器的数量的不同，进行实车标定获得，本发明只是给出防抖阈值和滤波窗口宽度的选取趋势。
四、车辆在其他路面下行驶的情况：
在水平路面上的ALS方法是在车辆低速行驶时求得的，但随着车速的增大，车辆的停车视距也随之增大，这就要求前照灯的照射范围需要覆盖更远距离的路面才能保证行车安全，因此，目标照射距离被表示为车速v的函数D(v)，可对式(1-4)修改后结合停车视距的定义，可将目标照射距离D(v)描述为车速v的分段函数：
因此，对式(3-7)、(3-8)、(3-9)进行修改：


对于车辆在粗糙路面上行驶时，路面的高频振动输入会导致车身的振动， 车身高度传感器的测量值也会产生高频抖动，从而导致ALS方法输出转角的抖动，由于算法中不可避免的延迟，车身的抖动与前照灯输出转角的抖动是不同步的，在这种情况下，ALS方法需要对粗糙路面进行识别，并在车辆进入粗糙路面时将ALS算法的输出屏蔽，即将前照灯的输出转角锁定在当前位置。
本实施例中采用机器学习中的决策树方法对路况信息进行识别，机器学习的通用流程包括四部分：特征选取与构建，数据采集、处理与数据集划分，模型训练与验证。
使用的决策树进行路面识别属于分类问题，其流程如图11所示，具体包括：
1、数据采集、处理与数据集划分：驾驶车辆行驶在各种路况/工况上(如下表所示)，每种路况/工况记录若干组数据(不少于十组)作为数据集，并通过车身高度传感器返回的数据的振幅进行区分好路和坏路，振幅明显的部分为坏路，其他为好路，将采集得到的所有数据按照约4：1的比例划分为训练集和测试集，需注意训练集中的好路和坏路的比例应当与测试集中的好路和坏路的比例相同。
表1需要采集数据的路况/工况
2、特征选取与构建：ALS方法在两传感器方案下的所有输入数据中，可 用于粗糙路面识别的有四个：左前车身高度传感器测量值，左后车身高度传感器测量值，车速，车辆轴向加速度。为了提高辨识效果，这里对输入数据进行处理，从每项输入数据中提取出六个特征变量：原始值，差分值，滑动窗口均值，滑动窗口标准差，滑动窗口最大值，滑动窗口最小值。下面以车速为例，介绍特征提取的具体方法。以下描述中的t0表示系统采样周期。
(1)原始值：直接将车速作为第一个特征即可。
(2)差分值：将t时刻的车速与t-t0时刻的车速相减，将这一差值作为t时刻的第二个特征。
(3)滑动窗口均值：对由t时刻，t-t0时刻，t-2t0时刻，t-3t0时刻，……t-nt0时刻的车速组成的序列求均值，将这一均值作为t时刻的第三个特征。n称为滑动窗口宽度，其具体数值可根据实验效果进行调整，本实施例中采用n＝15，下同。
(4)滑动窗口标准差：对由t时刻，t-t0时刻，t-2t0时刻，t-3t0时刻，……t-nt0时刻的车速组成的序列求标准差，将这一标准差作为t时刻的第四个特征。
(5)滑动窗口最大值：对由t时刻，t-t0时刻，t-2t0时刻，t-3t0时刻，……t-nt0时刻的车速组成的序列求最大值，将这一最大值作为t时刻的第五个特征。
(6)滑动窗口最小值：对由t时刻，t-t0时刻，t-2t0时刻，t-3t0时刻，……t-nt0时刻的车速组成的序列求最小值，将这一最小值作为t时刻的第六个特征。
对四项输入数据分别提取出以上六个特征，最终得到24个特征。对于每个采样点均可以按照上述方法提取出24个特征值，将其与标签(该采样点对应路况的好坏，0表示坏路，1表示好路)组成一个含有25个元素的向量，对训练集中的每个采样点生成这一向量，最终得到一个m0×25的矩阵(m0为训练集中的采样点总数)，将这一特征矩阵作为模型训练的输入即可。
3、模型训练、实现与验证：
决策树训练过程基于MATLAB所提供的决策树工具包，训练基本语句为：
Factor＝TreeBagger(1,Train_input,Train_Output,'Method','classification').
上式中，Train_input为特征矩阵中前24列组成的矩阵，Train_Output为特征矩阵中第25列向量，其余参数均为默认；最终得到的Factor是整个模型的参数，里面包含根据训练数据所建立模型的所有参数，从中最终可提取出一个m1×4的矩阵，m1为决策树的总节点数。这一矩阵包含了决策树相关的全部信息，由此矩阵可以对任意输入的特征向量(即特征矩阵中的某一行中的前24个元素组成的向量)输出一个识别结果——1(好路)或0(坏路)。这一矩阵的四列分别表示特征索引，分裂阈值，左子节点索引，输出结果。
在另一种实施例中，假定决策树由如下表矩阵表示：
表2决策树矩阵
输入特征向量如下表所示：
表3输入特征向量
则决策树实现流程如下：
(1)自决策树的第一行开始，其第一个元素为3，表示需要拿出输入特征向量中的第三个特征进行比较，即31；
(2)第一行第二个元素为60，则表明需要将31与60进行比较，得出31<60，说明决策树应该跳转至左子节点；
(3)第一行第三个元素为4，说明左子节点储存在矩阵的第四行， 因此决策树跳转至第四行，开始逐个检查决策树矩阵第四行的元素；
(4)决策树矩阵第四行第一个元素为6，第二个元素为21，则将输入特征向量中的第6个特征(即34)与21进行比较，得出34>21，说明决策树应跳转至右子节点；
(5)第四行第三个元素为7，说明右子节点储存在矩阵的第7+1＝8行，因此决策树跳转至第八行，开始逐个检查第八行的元素；
(6)第八行第一个元素为0，说明第八行对应节点为叶子节点(即决策终点)，直接将第八行的第四个元素1输出即可，表明表4中的特征向量对应采样点所在时刻车辆行驶在好路上。
如图12所示，为决策树实现的完整流程，模型训练完成后，需要在Simulink中搭建模型并进行仿真验证，根据验证准确率进行进一步优化，反复调整滑动窗口宽度n的值，直至达到理想的识别准确率。
在决策树模型的输出端添加一个补充策略，即统计过去一段时间内模型输出的“好路”与“坏路”所占时间的比例，若“好路”占比多则认为当前路面为好路，否则认为当前路面为坏路，从而减小了因少数某些点的误识别带来的负面影响。补充策略中的检测窗口同样需要经过反复试验得到，最终将其确定为75。
车辆在斜坡(指路面所在平面与重力方向不垂直、足够大的路面)和不同坡度路面间过渡时(低速和高速通过)，依然适用本发明所述的ALS方法。
本发明提供的车辆前照灯自动调平方法基于车身高度变化信号生成控制信号，相比惯性测量元件方案而言具有更高的稳定性和鲁棒性，并能够同时提供俯仰角、滚转角和垂向位移三个姿态数据用于输出转角的计算；通过三种工作模式为输出转角的调节设置阈值，只有当输出转角的变化量累积超过阈值时步进电机才会做出调整动作，避免了车身高频振动带来的输出转角频繁抖动影响驾驶员视野；除此以外，使用机器学习方法对粗糙路面进行识别并在粗糙路面上暂时禁用调节功能，进一步提高了前照灯照射范围的稳定性，用于在车辆姿态变化时自适应地垂直调节前照灯的照射方向，使得其照射范围保持稳定，避免因其照射位置过高或过低而导致的交通事故潜在风险。
需要说明的是，本说明书一个或多个实施例的方法可以由单个设备执 行，例如一台计算机或服务器等。本实施例的方法也可以应用于分布式场景下，由多台设备相互配合来完成。在这种分布式场景的情况下，这多台设备中的一台设备可以只执行本说明书一个或多个实施例的方法中的某一个或多个步骤，这多台设备相互之间会进行交互以完成所述的方法。
上述对本说明书特定实施例进行了描述。其它实施例在所附权利要求书的范围内。在一些情况下，在权利要求书中记载的动作或步骤可以按照不同于实施例中的顺序来执行并且仍然可以实现期望的结果。另外，在附图中描绘的过程不一定要求示出的特定顺序或者连续顺序才能实现期望的结果。在某些实施方式中，多任务处理和并行处理也是可以的或者可能是有利的。
本发明还提供了一种车辆前照灯自动调平装置，所述车辆前照灯自动调平装置包括：
路况信息获取模块，所述路况信息获取模块用于获取路况信息；
判断模块，所述用于根据所述路况信息判断当前路面是否为粗糙路面；
车身高度变化信号获取模块，所述车身高度变化信号获取模块用于在所述判断模块的判断结果为否时，获取多个预设位置的车身高度变化信号；
位姿信息获取模块，所述位姿信息获取模块用于根据所述多个预设位置的车身高度变化信号计算车辆位姿信息；
初始照准角获取模块，所述初始照准角获取模块用于获取初始照准角；
前照灯转角信息获取模块，所述前照灯转角信息获取模块用于在所述判断模块的判断结果为否时，根据所述车辆位姿信息和初始照射准点获得前照灯转角信息；
前照灯控制信号获取模块，所述前照灯控制信号获取模块用于根据所述前照灯转角信息生成前照灯控制信号；
发送模块，所述发送模块用于将所述前照灯控制信号发送至前照灯，以使前照灯根据所述前照灯控制信号进行灯光调平。
为了描述的方便，描述以上装置时以功能分为各种模块分别描述。当然，在实施本说明书一个或多个实施例时可以把各模块的功能在同一个或多个软件和/或硬件中实现。
上述实施例的装置用于实现前述实施例中相应的方法，并且具有相应的方法实施例的有益效果，在此不再赘述。
图14示出了本实施例所提供的一种更为具体的电子设备硬件结构示意图，该设备可以包括：处理器1010、存储器1020、输入/输出接口1030、通信接口1040和总线1050。其中处理器1010、存储器1020、输入/输出接口1030和通信接口1040通过总线1050实现彼此之间在设备内部的通信连接。
处理器1010可以采用通用的CPU(Central Processing Unit，中央处理器)、微处理器、应用专用集成电路(Application Specific Integrated Circuit，ASIC)、或者一个或多个集成电路等方式实现，用于执行相关程序，以实现本说明书实施例所提供的车辆前照灯自动调平方法。
存储器1020可以采用ROM(Read Only Memory，只读存储器)、RAM(Random Access Memory，随机存取存储器)、静态存储设备，动态存储设备等形式实现。存储器1020可以存储操作系统和其他应用程序，在通过软件或者固件来实现本说明书实施例所提供的技术方案时，相关的程序代码保存在存储器1020中，并由处理器1010来调用执行。
输入/输出接口1030用于连接输入/输出模块，以实现信息输入及输出。输入输出/模块可以作为组件配置在设备中(图中未示出)，也可以外接于设备以提供相应功能。其中输入设备可以包括键盘、鼠标、触摸屏、 麦克风、各类传感器等，输出设备可以包括显示器、扬声器、振动器、指示灯等。
通信接口1040用于连接通信模块(图中未示出)，以实现本设备与其他设备的通信交互。其中通信模块可以通过有线方式(例如USB、网线等)实现通信，也可以通过无线方式(例如移动网络、WIFI、蓝牙等)实现通信。
总线1050包括一通路，在设备的各个组件(例如处理器1010、存储器1020、输入/输出接口1030和通信接口1040)之间传输信息。
需要说明的是，尽管上述设备仅示出了处理器1010、存储器1020、输入/输出接口1030、通信接口1040以及总线1050，但是在具体实施过程中，该设备还可以包括实现正常运行所必需的其他组件。此外，本领域的技术人员可以理解的是，上述设备中也可以仅包含实现本说明书实施例方案所必需的组件，而不必包含图中所示的全部组件。
本发明的一个实施例提供了一种计算机可读存储介质，计算机可读存储介质存储有计算机程序，计算机程序被处理器执行时能够实现如上的车辆前照灯自动调平方法。
本实施例的计算机可读介质包括永久性和非永久性、可移动和非可移动媒体可以由任何方法或技术来实现信息存储。信息可以是计算机可读指令、数据结构、程序的模块或其他数据。计算机的存储介质的例子包括，但不限于相变内存(PRAM)、静态随机存取存储器(SRAM)、动态随机存取存储器(DRAM)、其他类型的随机存取存储器(RAM)、只读存储器(ROM)、电可擦除可编程只读存储器(EEPROM)、快闪记忆体或其他内存技术、只读光盘只读存储器(CD-ROM)、数字多功能光盘(DVD)或其他光学存储、 磁盒式磁带，磁带磁磁盘存储或其他磁性存储设备或任何其他非传输介质，可用于存储可以被计算设备访问的信息。
所属领域的普通技术人员应当理解：以上任何实施例的讨论仅为示例性的，并非旨在暗示本公开的范围(包括权利要求)被限于这些例子；在本公开的思路下，以上实施例或者不同实施例中的技术特征之间也可以进行组合，步骤可以以任意顺序实现，并存在如上所述的本说明书一个或多个实施例的不同方面的许多其它变化，为了简明它们没有在细节中提供。
另外，为简化说明和讨论，并且为了不会使本说明书一个或多个实施例难以理解，在所提供的附图中可以示出或可以不示出与集成电路(IC)芯片和其它部件的公知的电源/接地连接。此外，可以以框图的形式示出装置，以便避免使本说明书一个或多个实施例难以理解，并且这也考虑了以下事实，即关于这些框图装置的实施方式的细节是高度取决于将要实施本说明书一个或多个实施例的平台的(即，这些细节应当完全处于本领域技术人员的理解范围内)。在阐述了具体细节(例如，电路)以描述本公开的示例性实施例的情况下，对本领域技术人员来说显而易见的是，可以在没有这些具体细节的情况下或者这些具体细节有变化的情况下实施本说明书一个或多个实施例。因此，这些描述应被认为是说明性的而不是限制性的。
尽管已经结合了本公开的具体实施例对本公开进行了描述，但是根据前面的描述，这些实施例的很多替换、修改和变型对本领域普通技术人员来说将是显而易见的。例如，其它存储器架构(例如，动态RAM(DRAM))可以使用所讨论的实施例。
本说明书一个或多个实施例旨在涵盖落入所附权利要求的宽泛范围 之内的所有这样的替换、修改和变型。因此，凡在本说明书一个或多个实施例的精神和原则之内，所做的任何省略、修改、等同替换、改进等，均应包含在本公开的保护范围之内。

Claims (10)

  1. 一种车辆前照灯自动调平方法，其特征在于，所述车辆前照灯自动调平方法包括：
    获取路况信息；
    根据所述路况信息判断当前路面是否为粗糙路面；若否，则
    获取多个预设位置的车身高度变化信号；
    根据所述多个预设位置的车身高度变化信号计算车辆位姿信息；
    获取初始照准角；
    根据所述车辆位姿信息和初始照准角获得前照灯转角信息；
    根据所述前照灯转角信息生成前照灯控制信号。
  2. 如权利要求1所述的车辆前照灯自动调平方法，其特征在于，
    所述车辆前照灯自动调平方法还包括：
    根据所述路况信息判断当前路面是否为粗糙路面；若是，则
    生成锁止前照灯角度的控制信号；
    将所述锁止前照灯角度的控制信号发送至前照灯；
    以使前照灯根据所述前照灯控制信号锁止灯光角度。
  3. 如权利要求2所述的车辆前照灯自动调平方法，其特征在于，
    所述多个预设位置的车身高度变化信号包括：左前车身高度的相对变化量、左后车身高度的相对变化量、右前车身高度的相对变化量、右后车身高度的相对变化量；
    根据所述多个预设位置的车身高度变化信号计算车辆位姿信息包括：
    获取左前的车身高度传感器和左后的车身高度传感器之间的距离、左前的车身高度传感器和右前的车身高度传感器之间的距离；
    根据所述左前车身高度的相对变化量、左后车身高度的相对变化量、右前车身高度的相对变化量、右后车身高度的相对变化量、左前的车身高度传感器和左后的车身高度传感器之间的距离、左前的车身高度传感器和右前的 车身高度传感器之间的距离计算车辆位姿信息。
  4. 如权利要求3所述的车辆前照灯自动调平方法，其特征在于，
    所述根据所述车辆位姿信息和初始照准角获得前照灯转角信息包括：
    获取左侧前照灯与前轴的距离在车辆簧上质量坐标系X轴上的投影，左侧前照灯与右侧前照灯之间的距离，轴距，目标照射距离，车辆重心距地面高度；
    根据所述车辆位姿信息、初始照射准角、左侧前照灯与前轴的距离在车辆簧上质量坐标系X轴上的投影，左侧前照灯与右侧前照灯之间的距离，轴距，目标照射距离，车辆重心距地面高度计算前照灯转角信息。
  5. 如权利要求2所述的车辆前照灯自动调平方法，其特征在于，
    所述多个预设位置的车身高度变化信号包括：左前车身高度的相对变化量，左后车身高度的相对变化量；
    根据所述多个预设位置的车身高度变化信号计算车辆位姿信息包括：
    获取左前的车身高度传感器和左后的车身高度传感器之间的距离；
    根据所述左前车身高度的相对变化量、左后车身高度的相对变化量、左前的车身高度传感器和左后的车身高度传感器之间的距离计算车辆位姿信息。
  6. 如权利要求5所述的车辆前照灯自动调平方法，其特征在于，
    所述根据所述车辆位姿信息和初始照准角获得前照灯转角信息包括：
    获取前照灯安装高度、左侧前照灯与前轴的距离在车辆簧上质量坐标系X轴上的投影、轴距、目标照射距离、车辆重心距地面高度；
    根据所述车辆位姿信息、初始照准角、前照灯安装高度、左侧前照灯与前轴的距离在车辆簧上质量坐标系X轴上的投影、轴距、目标照射距离、车辆重心距地面高度计算前照灯转角信息。
  7. 如权利要求4或6中任意一项所述的车辆前照灯自动调平方法，其特征在于，
    所述获取目标照射距离包括：
    获取前照灯安装高度和车速；
    根据前照灯高度和车速获取目标照射距离。
  8. 如权利要求7所述的车辆前照灯自动调平方法，其特征在于，
    所述根据所述前照灯转角信息生成前照灯控制信号包括：
    获取输出转角的下限、输出转角的上限、防抖阈值、控制周期、上一时刻的步进电机的输出转角、限幅函数、当前时刻的输出转角缩放值；
    根据输出转角的下限、输出转角的上限、防抖阈值、控制周期、上一时刻的步进电机的输出转角、限幅函数、当前时刻的输出转角缩放值生成前照灯控制信号。
  9. 如权利要求8所述的车辆前照灯自动调平方法，其特征在于，
    获取当前时刻的输出转角缩放值包括：
    获取缩放系数、左侧前照灯输出转角和/或右侧前照灯输出转角；
    根据所述缩放系数、左侧前照灯输出转角和/或右侧前照灯输出转角计算当前时刻的输出转角缩放值。
  10. 一种车辆前照灯自动调平装置，其特征在于，所述车辆前照灯自动调平装置包括：
    路况信息获取模块，所述路况信息获取模块用于获取路况信息；
    判断模块，所述用于根据所述路况信息判断当前路面是否为粗糙路面；
    车身高度变化信号获取模块，所述车身高度变化信号获取模块用于在所述判断模块的判断结果为否时，获取多个预设位置的车身高度变化信号；
    位姿信息获取模块，所述位姿信息获取模块用于根据所述多个预设位置的车身高度变化信号计算车辆位姿信息；
    初始照准角获取模块，所述初始照准角获取模块用于获取初始照准角；
    前照灯转角信息获取模块，所述前照灯转角信息获取模块用于在所述判断模块的判断结果为否时，根据所述车辆位姿信息和初始照射准点获得前照 灯转角信息；
    前照灯控制信号获取模块，所述前照灯控制信号获取模块用于根据所述前照灯转角信息生成前照灯控制信号；
    发送模块，所述发送模块用于将所述前照灯控制信号发送至前照灯，以使前照灯根据所述前照灯控制信号进行灯光调平。
PCT/CN2023/095006 2022-11-21 2023-05-18 一种车辆前照灯自动调平方法及装置 WO2024108932A1 (zh)

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