A headlamp performance evaluation method and system

Abstract

The present invention relates to a vehicle headlamp performance evaluation method and system. The evaluation method specifically comprises: obtaining illuminance data for the desired projection surface of the headlamp to be evaluated; setting the measurement element size, measurement orientation, and measurement range corresponding to each evaluation indicator on the desired projection surface; calculating parameter data corresponding to the evaluation indicator based on the illuminance value of each measurement element, and evaluating the headlamp performance based on the parameter data. The present invention can process software simulation data and bench-measured data, automatically calculate all measurement points within the measurement range, accurately calculate the required specific illuminance illumination range, and can simultaneously process measurement points at different road surface heights.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile engineering, and in particular to performance evaluation of automobile headlamps. Background Art

[0002] Vehicle headlights play a vital role in nighttime road lighting. They include low beams and high beams, providing drivers with road illumination at night and in conditions like fog, rain, and snow. They help drivers spot obstacles or pedestrians ahead, allowing them to take evasive or braking measures. In recent years, public demand for headlight performance has increased, and the quality of headlights directly impacts driving safety. A good low beam should ensure a certain illumination distance and width, while avoiding glare in the opposite direction. A good high beam should also ensure a sufficient illumination distance and a certain illumination width and height.

[0003] The prior art proposes a bench test for the illuminance distribution of automobile low-beam headlights and a test method thereof, which provides a headlamp performance evaluation method based on bench testing. By reading the illuminance distribution diagram of the actual test equipment, the illuminance value at the fixed measuring point position is evaluated, and then the headlamp performance is evaluated. The defects of this patent are: 1. It can only process the actual test data; 2. It can only perform manual single-point measurement and cannot automatically calculate all measuring points within the measurement range; 3. It can only approximately evaluate the lighting range of the headlamp through the fixed-point illuminance value and cannot accurately determine the specific location; 4. It can only test a single road surface height measuring point, and multiple measurement conversions are required for measuring points at different road surface heights. Summary of the Invention

[0004] One of the purposes of the present invention is to provide a headlamp performance evaluation method to solve at least one of the problems of the background technology; the second purpose is to provide a headlamp performance evaluation system.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A vehicle headlamp performance evaluation method, the evaluation method specifically comprising:

[0007] Obtaining the illuminance data of the projection surface required by the headlamp to be evaluated;

[0008] Set the measurement element size, measurement orientation and measurement range corresponding to each evaluation index on the required projection surface;

[0009] The parameter data of the corresponding evaluation index is calculated according to the illumination value of each measured micro-element, and the performance of the headlamp is evaluated based on the parameter data.

[0010] According to the above technical means, by obtaining the projection surface illumination data of each evaluation index, and then setting the measurement element size, measurement orientation and measurement range corresponding to each evaluation index, the parameter data of the evaluation index is obtained. There is no need to read the physical test data, and there is no need for manual single-point measurement. All measurement points within the measurement range are automatically calculated.

[0011] Furthermore, the evaluation indicators include low beam indicators and high beam indicators. The low beam indicators include at least one of straight guidance distance, curve guidance distance, left pedestrian visibility, intersection pedestrian detection width, curve lighting width, luminous flux, and glare to oncoming drivers; the high beam indicators include at least one of lighting range, intersection pedestrian detection width, and luminous flux.

[0012] Furthermore, the method for determining the straight road guidance distance, the curve guidance distance, the left pedestrian visibility, and the lighting range is:

[0013] Divide P1 measurement positions on the required projection surface of the corresponding evaluation index,

[0014] For a certain measurement position within the range of maxU to minU, calculate the illuminance values ​​of all measurement cells one by one, and then calculate the exact position of the standard illuminance value slux1 between two adjacent measurement cells, and then return the distance value at which the light at the measurement position reaches the standard illuminance value;

[0015] Obtaining a mean D of the distance values ​​of all measurement directions, and evaluating the straight road guidance distance, curve guidance distance, left pedestrian visibility, and lighting range based on the mean D;

[0016] maxU to minU respectively represent the maximum value and the minimum value of the measurement range of the required projection surface.

[0017] Furthermore, the method for obtaining the precise position of the calculated standard illumination value slux1 between two adjacent measurement elements is: when Lux(j)>slux1 and Lux(j)≠Lux(j-1),

[0018] restdistj=(cellsize1×(Lux(j)-sLux1)) / (Lux(j)-Lux(j-1));

[0019] When Lux(j1)=Lux(j1-1),

[0020] restdistj=0.5×cellsize1;

[0021] If Lux(j-1) is empty, then Lux(j-1)=Lux(j).

[0022] When Lux(j)<slux1, distancej=0;

[0023] Lux(j) represents the illuminance of the jth measurement element;

[0024] cellsize1 is the measurement cell size when obtaining the straight road guidance distance, curve guidance distance, left pedestrian visibility or lighting range;

[0025] slux1 is the standard illumination value when obtaining the straight road guidance distance, curve guidance distance, left pedestrian visibility or lighting range;

[0026] restdistj represents the precise position of the standard illumination value slux1 of the certain measurement orientation between two adjacent measurement elements when obtaining the straight road guidance distance, curve guidance distance, left pedestrian visibility or lighting range.

[0027] According to the above technical means, the measured orientation can be divided into any number of measurement elements according to the actual situation, and then restdistj can be obtained through the mathematical method of interpolation, which effectively improves the accuracy of the calculation.

[0028] Furthermore, the method for obtaining the mean D of the distance values ​​of all measured orientations is:

[0029]

[0030] When Lux(j)>slux1, the straight-line guidance distance, the left pedestrian visibility, or the distance at which the light illumination in the lighting range reaches the standard illumination value slux1 is obtained as follows:

[0031] distancej=maxU-cellsize1×j+restdistj,

[0032] The method for obtaining the curve guidance distance is:

[0033] distancej=maxU-cellsize1×j+restdistj+s×tanα;

[0034] Wherein, distancej represents the distance value at which the straight road guidance distance, left pedestrian visibility, curve guidance distance, or lighting range obtained by obtaining the lighting illumination of a certain measurement direction reaches the standard illumination value slux1;

[0035] s represents the offset of the starting position of the road centerline of the opposite lane;

[0036] α represents the angle between the calculated measurement direction and the driving direction;

[0037] n1 represents the number of measurement elements of the certain measurement orientation.

[0038] Furthermore, a method for obtaining parameter data for evaluating the pedestrian detection width at the intersection, the pedestrian detection width at the intersection of the low beam indicator, or the pedestrian detection width at the intersection of the high beam indicator is as follows:

[0039] Divide p2 measurement positions in the vertical direction of the required projection surface of the corresponding evaluation index;

[0040] Calculate the illumination values ​​of all measurement elements one by one within the range of minV to maxV for a certain measurement position.

[0041] Calculate the exact position of the standard illuminance value slux2 between two adjacent measurement elements in the range of maxV to 0 and in the range of minV to 0 respectively, and then return the distance value at which the light illumination in the range of maxV to 0 and in the range of minV to 0 in the measurement direction reaches the said standard illuminance value slux2 respectively;

[0042] Obtaining a mean E of the distance values ​​of all measured orientations;

[0043] When obtaining parameter data for evaluating the lighting range, the corresponding measurement orientation is set to form a spatial angle β with the U direction;

[0044] minV to maxV represent the minimum and maximum values ​​of the measurement range perpendicular to the desired projection plane, respectively;

[0045] U direction is the direction of vehicle travel;

[0046] β represents the solid angle formed by the U direction.

[0047] Furthermore, the method for obtaining the precise position of the standard illuminance value slux2 between two adjacent measurement elements is as follows:

[0048] When Lux(k)>slux2 and Lux(k)≠Lux(k-1),

[0049] restdistk=(cellsize2×(Lux(k)-sLux2)) / (Lux(k)-Lux(k-1));

[0050] When Lux(k)=Lux(k-1),

[0051] restdistk=0.5×cellsize2;

[0052] If Lux(k-1) is empty, then Lux(k-1)=Lux(k);

[0053] Lux(k) represents the illuminance of the kth measurement element in the range of maxV to 0 or minV to 0 at the measurement position;

[0054] k represents a measurement element in the range of maxV to 0 or minV to 0 at the measurement position;

[0055] cellsize2 is the measurement cell size within the range of maxV to 0 or minV to 0 at the measurement position;

[0056] slux2 is a standard illumination value for obtaining parameter data of the pedestrian detection width at the intersection, the pedestrian detection width at the intersection of the low beam indicator, or the pedestrian detection width at the intersection of the high beam indicator.

[0057] Furthermore, the method for obtaining the mean E of the distance values ​​of all measured orientations is:

[0058]

[0059] distancek=|distance(max1)|+|distance(min1)|

[0060] When Lux(k)>slux2;

[0061] distance(max1) or distance(min1) = maxW - cellsize2 × n2 + restdistk;

[0062] When Lux(k)<slux2, distance(max1) or distance(mmin1)=0;

[0063] Wherein, distancek represents the distance value at which the lighting on the first side of the road centerline reaches the illuminance of sLux2 at a certain measurement direction;

[0064] n2 represents the number of measurement elements within the range of maxV to 0 or minV to 0 in the measurement orientation; maxW represents the maximum value of the measurement range on the desired projection surface.

[0065] Furthermore, the method for obtaining parameter data for evaluating the luminous flux of the low beam indicator, the glare to the driver, or the luminous flux of the high beam indicator is as follows:

[0066] On the corresponding desired projection surface, calculate the illumination values ​​of all measurement elements one by one within the range enclosed by maxY to minY and maxZ to minZ;

[0067] To evaluate the glare of the oncoming driver, the illuminance values ​​in all the measurement cells are obtained, multiplied by the weight values ​​of the corresponding divided areas, and then accumulated;

[0068] For evaluating the luminous flux of the low beam indicator or the luminous flux of the high beam indicator, the illuminance values ​​in all the measurement cells are obtained and accumulated;

[0069] Wherein: maxY to minY represent the maximum value and minimum value of the measurement range in the horizontal direction of the projection plane required to evaluate the luminous flux of the low beam indicator, the glare towards the driver, or the luminous flux of the high beam indicator, respectively;

[0070] maxZ to minZ respectively represent the maximum value and the minimum value of the measurement range in the vertical direction of the required projection surface for evaluating the luminous flux of the low beam indicator, the glare toward the driver, or the luminous flux of the high beam indicator.

[0071] Furthermore, the required projection surface reading data is obtained by converting optical data through the projection method and the inverse square law of distance based on the parameters of the distance W between the low beam or high beam on the left and right sides of the vehicle, the height from the ground H, and the tilt angle A.

[0072] A vehicle headlamp performance evaluation system based on the above evaluation method,

[0073] It includes: an illuminance data acquisition module, configured to obtain illuminance data of a projection surface required by the headlamp to be evaluated;

[0074] A setting module is configured to set the measurement element size, measurement orientation and measurement range corresponding to each evaluation index on the required projection surface;

[0075] A parameter data acquisition module is configured to calculate parameter data corresponding to the evaluation index according to the illumination value of each measured micro-element;

[0076] The evaluation module is configured to evaluate the performance of the headlamp based on the parameter data.

[0077] A computer-readable medium stores computer-readable instructions, which, when executed by a processor of a computer, enable the computer to execute the above method.

[0078] Beneficial effects of the present invention:

[0079] The present invention can process software simulation data and bench measured data, automatically calculate all measuring points within the measurement range, accurately calculate the required specific illumination range, and can process measuring points at different road heights at the same time, thereby saving testing workload and improving testing efficiency.

[0080] The present invention can automatically and accurately calculate the data of each evaluation item based on the headlamp installation parameters, simulation or measured optical data, and the test indicators of each evaluation item can be flexibly adjusted. When calculating the corresponding parameter data, the measurement orientation can be divided into multiple measurement elements, and the length and number of the measurement elements can be adjusted according to individual needs. The final parameter data is obtained through interpolation mathematical calculation, which ensures the accuracy of the calculation while saving testing workload. BRIEF DESCRIPTION OF THE DRAWINGS

[0081] Figure 1 Flowchart of the present invention;

[0082] Figure 2 Convert optical data into projection surface illumination map;

[0083] Figure 3 This is a schematic diagram of the low beam straight guidance distance algorithm;

[0084] Figure 4 This is a schematic diagram of the low beam curve guidance distance algorithm;

[0085] Figure 5 This is a schematic diagram of the pedestrian visibility algorithm on the left side of the low beam;

[0086] Figure 6 This is a schematic diagram of the pedestrian detection width algorithm at low-beam intersections;

[0087] Figure 7 This is a schematic diagram of the low beam cornering lighting width algorithm;

[0088] Figure 8 This is a schematic diagram of the low beam flux algorithm;

[0089] Figure 9 This is a schematic diagram of the algorithm for dazzling oncoming drivers with low beams;

[0090] Figure 10 This is a schematic diagram of the high beam lighting range algorithm;

[0091] Figure 11 This is a schematic diagram of the high-beam intersection pedestrian detection width algorithm;

[0092] Figure 12 This is a schematic diagram of the high beam flux algorithm;

[0093] Figure 13 Schematic diagram of the headlamp performance evaluation system.

[0094] Among them, 1-illuminance data acquisition module; 2-setting module; 3-parameter data acquisition module; 4-evaluation module. DETAILED DESCRIPTION

[0095] The following will describe the implementation of the technical solution of the present invention with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for the purpose of illustrating the present invention and are not intended to limit the scope of protection of the present invention.

[0096] It should be noted that the illustrations provided in the following embodiments are merely schematic illustrations of the basic concept of the present invention. Therefore, the illustrations only show components related to the present invention and are not drawn according to the number, shape, and size of components in actual implementation. In actual implementation, the type, quantity, and proportion of each component may be changed arbitrarily, and the component layout may also be more complex.

[0097] Example 1

[0098] like Figure 1 As shown, this embodiment proposes a headlamp performance evaluation method, specifically:

[0099] Step 1: Obtain the illuminance data of the projection surface required by the headlamp to be evaluated.

[0100] Specifically, according to the parameters of the distance W between the low beam or high beam on the left and right sides of the vehicle, the ground clearance H, and the tilt angle A, the software simulation data or bench test data are transferred to the correct position, and the calculation is directly performed according to the needs of each evaluation item algorithm, or the optical data is converted into the required projection surface illumination data through the projection method and the inverse square law of distance.

[0101] Furthermore, the lamp installation position and vertical tilt angle are determined according to the parameters of the left and right low beam distance W1, the high beam distance W2, the low beam ground clearance H1, the high beam ground clearance H2, the low beam vertical tilt angle A1, and the high beam vertical tilt angle A2, as shown in Table 1.

[0102] Table 1 Lamp installation position table

[0103] Function X coordinate Y coordinate Z coordinate Vertical tilt angle Low beam (left) 0 W1 / 2 H1 A1 Low beam (right) 0 -W1 / 2 H1 A1 High beam (left) 0 W2 / 2 H2 A2 High beam (right) 0 -W2 / 2 H2 A2

[0104] Furthermore, if Figure 2 As shown, based on the fixture installation position and downtilt angle information, software simulation data or bench test data is transferred to the correct position, which represents the fixture installation position. Alternatively, optical data is converted into the required projection surface illuminance data using the projection method and the inverse square law of distance. Depending on the evaluation requirements, the required projection surface illuminance data can be one or more.

[0105] Step 2: As shown in Table 2, set the measurement element size, measurement orientation, and measurement range corresponding to each evaluation index on the required projection surface.

[0106] The measurement element refers to the smallest unit for measuring illuminance value. The algorithm will integrate and solve the illuminance value of the smallest unit. Its shape can be a rectangle, circle or other shapes on the projection surface, or a rectangle, circle or other shapes that form a spatial angle with the projection surface, or a part of a cylindrical surface or spherical surface that is cut by the projection surface and located on the side of the projection surface illuminated by the light.

[0107] Measuring the size of a microelement refers to measuring the projection size of the microelement in the normal direction of the projection surface. The projection shape can be rectangular, circular, etc. To ensure the accuracy of the algorithm, the measured microelement size should be much smaller than the projection surface size.

[0108] Table 2 Parameter setting items in this embodiment

[0109]

[0110]

[0111]

[0112]

[0113] Step 3: Calculate the parameter data of the corresponding evaluation index based on the illumination value of each measured element, and evaluate the performance of the headlamp based on the parameter data.

[0114] In this embodiment, the indicators that need to be evaluated include low beam indicators and high beam indicators. The low beam indicators include straight guidance distance, curve guidance distance, left pedestrian visibility, pedestrian detection width at intersections, curve lighting width, luminous flux, and glare for oncoming drivers; the high beam indicators include lighting range, pedestrian detection width at intersections, and luminous flux.

[0115] The parameter data calculation method of the above indicators is as follows:

[0116] 1. Low beam

[0117] Straight lead distance

[0118] Set the parameters as shown in Table 2. Figure 3As shown, along p straight lines with a constant V coordinate, within the range of maxU to minU, the illuminance values ​​of the first to nth measurement units are calculated one by one. When the illuminance value Lux(n) of the nth unit is greater than the measurement standard illuminance value slux, the logical judgment in Table 3 is performed, and the precise position restdist of the measurement standard illuminance value slux between two adjacent measurement units is obtained through interpolation calculation, and the distance value is returned. A total of p*m distance values ​​are returned for p measurement positions that meet m measurement standard illuminance values.

[0119] Table 3 Logic table for calculating parameter data for evaluating straight-line guidance distance

[0120]

[0121] The mathematical expression is as follows:

[0122] The required projection surface illumination is divided into P11 measurement positions, and each measurement position is divided into n 11 The measurement element is then used to obtain D1 as follows:

[0123]

[0124] When Lux(j1)>slux11, distancej1=maxU1-cellsize11×j1+restdistj1,

[0125] When Lux(j1)≠Lux(j1-1),

[0126] restdistj1=(cellsize11×(Lux(j1)-sLux11)) / (Lux(j1)-Lux(j1-1));

[0127] When Lux(j1)=Lux(j1-1),

[0128] restdistj1=0.5×cellsize11;

[0129] If Lux(j1-1) is empty, then Lux(j1-1)=Lux(j1);

[0130] When Lux(j1)<slux11, distancej1=0;

[0131] Wherein, distancej1 represents a certain measurement element at a certain measurement direction, and Lux(j1) represents the illuminance of the j1th measurement element;

[0132] cellsize11 is the measurement cell size set when obtaining the straight guide distance;

[0133] slux11 is the standard illumination value set when obtaining the straight guide distance;

[0134] restdistj1 represents the distance between the center of the j1th element and the sLux11 illumination point;

[0135] D1 represents the average distance at which the lighting obtained from P11 measurement positions reaches the illuminance of sLux11.

[0136] Curve guidance distance

[0137] Set the parameters as shown in Table 2. Figure 4 As shown, along p diagonal lines α degrees from the U direction and spaced s apart from the origin, the illuminance values ​​of the first to n measurement units are calculated within the range maxU to minU. When the illuminance value Lux(n) of the nth unit is greater than the measured standard illuminance value slux, the logical judgment shown in Table 4 is performed, and the precise position of the measured standard illuminance value slux between two adjacent measurement units is determined through interpolation, and the distance value is returned. A total of p*m distance values ​​are returned for p measurement positions that meet m measured standard illuminance values. The U direction represents the vehicle's direction of travel. The tangent line of the vehicle's travel on a curve is not in the U direction.

[0138] Table 4 Parameter data logic table for evaluating curve guidance distance

[0139]

[0140]

[0141] The specific calculation can be done using the following mathematical expression:

[0142] The required projection surface illumination is divided into P 12 measurement positions, each measurement position is divided into n 12 The measurement element is then used to obtain D2 as follows:

[0143]

[0144] When Lux(j2)>slux12, distancej2=maxU2-cellsize11×n 12 +restdistj2+s×tanα

[0145] When Lux(j2)≠Lux(j2-1),

[0146] restdistj2=(cellsize12×(Lux(j2)-sLux12)) / (Lux(j2)-Lux(j2-1));

[0147] When Lux(j2)=Lux(j2-1),

[0148] restdistj2=0.5×cellsize12;

[0149] If Lux(j2-1) is empty, then Lux(j2-1)=Lux(j2);

[0150] When Lux(j2)<slux12, distancej2=0;

[0151] Wherein, distancej2 represents the distance value at which the light illumination at a certain measurement direction reaches the standard illumination value slux12;

[0152] Lux(j2) represents the illuminance of the j2th measurement element;

[0153] cellsize12 is the measurement cell size set when obtaining parameter data for evaluating curve guidance distance;

[0154] slux12 is the standard illumination value set when obtaining parameter data for evaluating curve guidance distance;

[0155] maxU2 represents the maximum value of the measurement range set when obtaining parameter data for evaluating the curve guide distance;

[0156] α represents the angle between the calculated measurement direction and the driving direction;

[0157] restdistj2 represents the distance between the center of the j2th microelement and the sLux12 illumination point;

[0158] D2 represents the average distance at which the lighting obtained from P2 measurement positions reaches sLux12 illumination;

[0159] Indicates the offset of the starting position of the road centerline of the opposite lane.

[0160] Left pedestrian visibility

[0161] Set the parameters as shown in Table 2. Figure 5As shown, along p straight lines with a constant V coordinate, within the range of maxU to minU, the illuminance values ​​of the first to nth measurement units are calculated one by one. When the illuminance value Lux(n) of the nth unit is greater than the measurement standard illuminance value slux, the logical judgment in Table 5 is performed, and the precise position restdist of the measurement standard illuminance value slux between two adjacent measurement units is obtained through interpolation calculation, and the distance value is returned. A total of p*m distance values ​​are returned for p measurement positions that meet m measurement standard illuminance values.

[0162] Table 5 Parameter data logic table for evaluating left pedestrian visibility

[0163]

[0164] Or use the following mathematical expression to calculate:

[0165] The method for obtaining the parameter data for evaluating the visibility of the pedestrian on the left side is: dividing the required projection surface illumination into P 13 measurement positions, each measurement position is divided into n 13 The measurement element is then used to obtain D3 as follows:

[0166]

[0167] When Lux(j3)>slux13, distancej3=maxU3-cellsize3×j3+restdistj3

[0168] When Lux(j3)≠Lux(j3-1),

[0169] restdistj3=(cellsize13×(Lux(j3)-sLux13)) / (Lux(j3)-Lux(j3-1));

[0170] When Lux(j3)=Lux(j3-1),

[0171] restdistj3=0.5×cellsize13;

[0172] If Lux(j3-1) is empty, then Lux(j3-1)=Lux(j3);

[0173] When Lux(j3)<slux13, distancej3=0;

[0174] Wherein, distancej3 represents the distance value at which the light illumination at a certain measurement direction reaches the standard illumination value slux13; Lux(j3) represents the illumination of the j3th measurement element;

[0175] cellsize13 is the measurement cell size set when obtaining parameter data for evaluating the visibility of pedestrians on the left side;

[0176] slux13 is the standard illumination value set when obtaining parameter data for evaluating the visibility of pedestrians on the left side;

[0177] maxU3 represents the maximum value of the measurement range set when obtaining parameter data for evaluating the visibility of pedestrians on the left side;

[0178] restdistj3 represents the distance between the center of the j3th element and the sLux13 illumination point;

[0179] D3 represents the average distance at which the lighting obtained from the P13 measurement positions reaches the sLux13 illumination level. D3 is used to evaluate the visibility of pedestrians on the left side.

[0180] Curve lighting width

[0181] Set the parameters as shown in Table 2. Figure 6 As shown, along the p straight lines with constant U coordinates, in the range of maxV to 0, the illuminance values ​​in the 1st to nth measurement units are calculated one by one. When the illuminance value Lux(n) of the nth unit is greater than the measurement standard illuminance value slux, the logical judgment in Table 6 is performed, and the precise position restdist of the measurement standard illuminance value slux between two adjacent measurement units is obtained by interpolation calculation, and the distance(max) value is returned.

[0182] According to the above algorithm, in the range of minV to 0, calculate the distance(min) value again. Add the absolute values ​​of distance(max) and distance(min) to get the distance value. A total of p measurement positions and p*m distance values ​​that meet m measurement standard illumination values ​​are returned. Distance(max1) and distance(min1) are calculated separately, because for the software, the left side of the road to 0 (the center line of the road) is the positive part (that is, the area where distance(max1) is located), and the right side of the road to 0 is the negative part (that is, the area where distance(min1) is located). The positive and negative parts need to be divided into micro-elements for calculation, and then the absolute values ​​are added to get the entire width.

[0183] Table 6 Parameter data logic table for evaluating the width of curved lighting

[0184]

[0185]

[0186] The method for obtaining parameter data for evaluating the width of the curved road lighting is as follows: the projection plane perpendicular to the desired width of the curved road lighting is divided into P 21 measurement positions, each of which is divided into n 21 The road centerline is used as the dividing line, and the first side of the road centerline is divided into n 211 measurement elements, the second side of the road centerline is divided into n 212 measurement elements, where n 21 =n 211 +n 212 , and then obtain E1 as follows:

[0187]

[0188] distancek1=|distance(max1)|+|distance(min1)|

[0189] When Lux(k1)>slux21, distance(max1)=maxW1-cellsize211×k11+restdistk11;

[0190] When Lux(k11)≠Lux(k11-1),

[0191] restdistk11=(cellsize211×(Lux(k11)-sLux21)) / (Lux(k11)-Lux(k11-1));

[0192] When Lux(k11)=Lux(k11-1),

[0193] restdistk11=0.5×cellsize211;

[0194] If Lux(k11-1) is empty, then Lux(k11-1)=Lux(k11);

[0195] When Lux(k11)<slux21, distancek11=0;

[0196] k11 represents a certain measurement element on the first side of the road centerline at the measurement direction, 1≤k11≤n 51 ;

[0197] k12 represents a certain measurement element on the second side of the road centerline at the measurement direction, 1≤k12≤n 52 ;

[0198] When Lux(k12)>slux21, distance(min1)=minW1-cellsize212×k12+restdistk12;

[0199] When Lux(k12)≠Lux(k12-1),

[0200] restdistk12=(cellsize212×(Lux(k12)-sLux21)) / (Lux(k12)-Lux(k12-1));

[0201] When Lux(k12)=Lux(k12-1),

[0202] restdistk12=0.5×cellsize52;

[0203] If Lux(k12-1) is empty, then Lux(k12-1)=Lux(k12);

[0204] When Lux(k12)<slux21, distancek12=0;

[0205] Wherein, distancek11 represents the distance value at which the lighting on the first side of the road centerline reaches the sLux5 illumination at a certain measurement direction;

[0206] distancek12 represents the distance at which the lighting on the second side of the road centerline reaches sLux5 illumination in the measurement direction;

[0207] Lux(k11) represents the jth position on the first side of the road centerline at the measurement position. 51 The illumination of each measuring element;

[0208] Lux(k12) represents the jth position on the second side of the road centerline at the measurement position. 52 The illumination of each measuring element;

[0209] cellsize211 is the measurement cell size set on the first side of the road centerline at the measurement orientation when obtaining parameter data for evaluating the pedestrian detection width at the intersection;

[0210] cellsize212 is the measurement cell size set on the second side of the road centerline at the measurement orientation when obtaining parameter data for evaluating the pedestrian detection width at the intersection;

[0211] slux21 is the standard illumination value set when obtaining parameter data for evaluating the curved road lighting width;

[0212] maxW1 represents the maximum value of the measurement range set when obtaining the parameter data for evaluating the width of the curved lighting.

[0213] Pedestrian detection width at intersections

[0214] Set the parameters as shown in Table 2. Figure 7 As shown, along the p straight lines with constant U coordinates, in the range of maxV to 0, the illuminance values ​​in the 1st to nth measurement units are calculated one by one. When the illuminance value Lux(n) of the nth unit is greater than the measurement standard illuminance value slux, the logical judgment in Table 7 is performed, and the precise position restdist of the measurement standard illuminance value slux between two adjacent measurement units is obtained by interpolation calculation, and the distance(max) value is returned.

[0215] Using the above algorithm, calculate the distance(min) value again within the range of minV to 0. Add the absolute values ​​of distance(max) and distance(min) to obtain the distance value. This returns a total of p*m distance values ​​for p measurement positions and m measurement standard illuminance values.

[0216] Table 7 Parameter data logic table for evaluating pedestrian detection width at intersections

[0217]

[0218] The mathematical expression is:

[0219] The illumination of the projection surface of the required intersection pedestrian detection width is divided into P 22 measurement positions, each measurement position is divided into n 22 The road centerline is used as the dividing line, and the first side of the road centerline is divided into n 221 measurement elements, the second side of the road centerline is divided into n 222 measurement elements, where n 22 =n 221 +n 222 , and then obtain E2 as follows:

[0220]

[0221] distancek2=|distance(max2)|+|distance(min2)|

[0222] When Lux(k21)>slux22, distance(max1)=maxW2-cellsize221×k21+restdistk21;

[0223] When Lux(k21)≠Lux(k21-1),

[0224] restdistk21=(cellsize221×(Lux(k21)-sLux21)) / (Lux(k21)-Lux(k21-1));

[0225] When Lux(k21)=Lux(k21-1),

[0226] restdistk21=0.5×cellsize221;

[0227] If Lux(k21-1) is empty, then Lux(k21-1)=Lux(k21);

[0228] When Lux(k21)<slux22, distancek21=0;

[0229] distance(min2)=maxW2-cellsize222×k22+restdistk22;

[0230] When Lux(k22)>slux22, distance(min2)=maxW2-cellsize222×k22+restdistk22;

[0231] When Lux(k22)≠Lux(k22-1),

[0232] restdistk22=(cellsize222×(Lux(k22)-sLux22)) / (Lux(k22)-Lux(k22-1));

[0233] When Lux(k22)=Lux(k22-1),

[0234] restdistk22=0.5×cellsize222;

[0235] If Lux(k22-1) is empty, then Lux(k22-1)=Lux(k22);

[0236] When Lux(k22)<slux22, distancej 42 =0;

[0237] Wherein, distancek21 represents the distance value at which the lighting on the first side of the road centerline reaches the illuminance of sLux4 at a certain measurement direction;

[0238] distancek22 represents the distance at which the lighting on the second side of the road centerline reaches sLux4 illumination at the measurement direction;

[0239] Lux(k21) represents the jth position on the first side of the road centerline at the measurement position. 41 The illumination of each measuring element;

[0240] Lux(k22) represents the jth position on the second side of the road centerline at the measurement position. 42 The illumination of each measuring element;

[0241] k21 represents a certain measurement element on the first side of the road centerline at the measurement direction, 1≤j 41 ≤n 41 ;

[0242] k22 represents a certain measurement element on the second side of the road centerline at the measurement direction, 1≤j 42 ≤n 42 ;

[0243] cellsize221 is the measurement cell size set on the first side of the road centerline at the measurement orientation when obtaining parameter data for evaluating the pedestrian detection width at the intersection;

[0244] cellsize222 is the measurement cell size set on the second side of the road centerline at the measurement orientation when obtaining parameter data for evaluating the pedestrian detection width at the intersection;

[0245] slux22 is the standard illumination value set when obtaining parameter data for evaluating the pedestrian detection width at the intersection;

[0246] maxW2 represents the maximum value of the measurement range set when obtaining parameter data for evaluating the pedestrian detection width at the intersection.

[0247] Luminous flux

[0248] Set the parameters as shown in Table 2. Figure 8 As shown, in the range from maxU to minU and from maxV to minV, the illuminance values ​​in the 1st to nth measurement elements are calculated one by one, and the value is obtained by accumulating them.

[0249] Dazzling oncoming drivers

[0250] Set the parameters as shown in Table 2. Figure 9 As shown, in the range enclosed by maxU to minU and maxV to minV, the illumination values ​​in the 1st to nth measurement elements are calculated one by one, and the values ​​are multiplied by the weight values ​​of the corresponding divided areas and then accumulated to obtain the value.

[0251] 2. High beam indicator

[0252] Lighting range

[0253] Set the parameters as shown in Table 2. Figure 10 As shown, the aforementioned method for obtaining the required projection surface illuminance, the projection surface position can be customized, but it is pre-defined here. Because the high beam illumination range is a conical surface with a constrained angle (multiple angles), there is no way to directly determine the projection surface (that is, the optical data is not converted to the final projection surface), so it is necessary to first find the intersection point at each calculation position, and then convert the position on the original optical data for calculation. Specifically, the method for obtaining the required projection surface illuminance of the illumination range is as follows:

[0254] Along p straight lines that form a spatial angle β with the U direction, within the range of maxU to minU, calculate the intersection point lpos between the projection plane perpendicular to the U direction and the straight line at the locations of the first to nth measurement elements. Based on the line connecting the projection plane position lpos and the left and right lamp installation locations, determine the intersection point (u, v) where the connecting line intersects with the optical data location described in step 1. Calculate the luminous intensity value at this point, and calculate the illuminance on the projection plane using the inverse square law of distance.

[0255] When the illuminance value Lux(n) of the nth element is greater than the measured standard illuminance value slux, the logical judgment shown in Table 8 is performed, and the precise position restdist of the measured standard illuminance value slux between two adjacent measured elements is calculated through interpolation, and the distance value is returned. A total of p*m distance values ​​are returned for p measured positions and m measured standard illuminance values.

[0256] Table 8 Parameter data logic table for evaluating lighting range

[0257]

[0258] It can also be calculated using mathematical expressions, specifically:

[0259] The required projection surface illumination is divided into P14 measurement positions. All the measurement positions make a spatial angle β with the U direction. Each measurement position is divided into measurement elements. Then D4 is obtained as follows:

[0260]

[0261] When Lux(j4)>slux14, distancej4=maxU4-cellsize14×n 14 +restdistj4,

[0262] When Lux(j4)≠Lux(j4-1),

[0263] restdistj4=(cellsize14×(Lux(j4)-sLux14)) / (Lux(j4)-Lux(j4-1));

[0264] When Lux(j4)=Lux(j4-1),

[0265] restdistj4=0.5×cellsize14;

[0266] If Lux(j4-1) is empty, then Lux(j4-1)=Lux(j4);

[0267] When Lux(j4)<slux14, distancej4=0;

[0268] Wherein, distancej4 represents the distance value at which the light of a certain measurement position reaches the standard illumination value slux14

[0269] Lux(j4) represents the illuminance of the j4th measurement element;

[0270] cellsize14 is the measurement cell size set when obtaining the straight guide distance;

[0271] slux14 is the standard illumination value set when obtaining the straight guide distance;

[0272] restdistj4 represents the distance between the center of the j4th element and the sLux14 illumination point;

[0273] D4 represents the average distance at which the lighting obtained from the P14 measurement positions reaches the sLux14 illumination. D4 is used to evaluate the lighting range.

[0274] The U direction is the vehicle's forward direction, that is, the direction of the light;

[0275] The β angle is the solid angle formed with the U direction. Countless lines of the β angle merged together form a conical surface or a part of a conical surface with the U direction as the axis.

[0276] Pedestrian detection width at intersections

[0277] Set the parameters as shown in Table 2. Figure 11As shown, along the p straight lines with constant U coordinates, in the range of maxV to 0, the illuminance values ​​in the 1st to nth measurement units are calculated one by one. When the illuminance value Lux(n) of the nth unit is greater than the measurement standard illuminance value slux, the logical judgment in Table 9 is performed, and the precise position restdist of the measurement standard illuminance value slux between two adjacent measurement units is obtained by interpolation calculation, and the distance(max) value is returned.

[0278] Using the above algorithm, calculate the distance(min) value again within the range of minV to 0. Add the absolute values ​​of distance(max) and distance(min) to obtain the distance value. This returns a total of p*m distance values ​​for p measurement positions and m measurement standard illuminance values.

[0279] Table 9 Parameter data logic table for evaluating pedestrian detection width at intersections

[0280]

[0281] The method for obtaining parameter data for evaluating the pedestrian detection width at intersections is as follows: the required projection surface illumination is divided into P 23 measurement positions, each of which is divided into n 23 The road centerline is used as the dividing line, and the first side of the road centerline is divided into n 231 measurement elements, the second side of the road centerline is divided into n 232 measurement elements, where n 23 =n 231 +n 232 , and then obtain E3 as follows:

[0282]

[0283] distancek3=|distance(max3)|+|distance(min3)|

[0284] When Lux(k31)>slux23,

[0285] distance(max3)=maxW3-cellsize231×k31+restdistk23;

[0286] When Lux(k31)≠Lux(k31-1),

[0287] restdistk31=(cellsize231×(Lux(k31)-sLux23)) / (Lux(k31)-Lux(k31-1));

[0288] When Lux(k31)=Lux(k31-1),

[0289] restdistk31=0.5×cellsize231;

[0290] If Lux(k31-1) is empty, then Lux(k31-1)=Lux(k31);

[0291] When Lux(k31)<slux23, distancek31=0;

[0292] When Lux(k32)>slux23,

[0293] distance(min3)=maxW3-cellsize232×k32+restdistk32;

[0294] When Lux(k32)≠Lux(k32-1),

[0295] restdistk32=(cellsize232×(Lux(k32)-sLux23)) / (Lux(k32)-Lux(k32-1));

[0296] When Lux(k32)=Lux(k32-1),

[0297] restdistk32=0.5×cellsize232;

[0298] If Lux(k32-1) is empty, then Lux(k32-1)=Lux(k32);

[0299] When Lux(k32)<slux23, distancek32=0;

[0300] Wherein, distancek31 represents the distance value at which the lighting on the first side of the road centerline reaches sLux7 illumination at a certain measurement direction;

[0301] distancek32 represents the distance at which the lighting on the second side of the road centerline reaches sLux7 illumination in the measurement direction;

[0302] Lux(k31) represents the jth position on the first side of the road centerline at the measurement position. 71 The illumination of each measuring element;

[0303] Lux(k32) represents the jth position on the second side of the road centerline at the measurement position. 72The illumination of each measuring element;

[0304] k31 represents a certain measurement element on the first side of the road centerline at the measurement direction, 1≤j 71 ≤n 71 ;

[0305] k32 represents a measurement element on the second side of the road centerline at the measurement direction, 1≤j 72 ≤n 72 ;

[0306] cellsize231 is the measurement cell size set on the first side of the road centerline at the measurement orientation when obtaining parameter data for evaluating the pedestrian detection width at the intersection;

[0307] cellsize232 is the measurement cell size set on the second side of the road centerline at the measurement orientation when obtaining parameter data for evaluating the pedestrian detection width at the intersection;

[0308] slux23 is the standard illumination value set when obtaining parameter data for evaluating the width of the curved road lighting;

[0309] maxW3 represents the maximum value of the measurement range set when obtaining parameter data for evaluating the pedestrian detection width at the intersection; luminous flux

[0310] Set the parameters as shown in Table 2. Figure 12 As shown, in the range from maxU to minU and from maxV to minV, the illuminance values ​​in the 1st to nth measurement elements are calculated one by one, and the value is obtained by accumulating them.

[0311] Step 4: Calculate and process the measurement results as shown in Table 10 to obtain the final result of the evaluation item.

[0312] Table 10 Calculation result return table

[0313]

[0314]

[0315] The calculation of headlamp performance on a hypothetical vehicle model is used as a specific embodiment.

[0316] According to the parameters of the distance W between the low beam or high beam on the left and right sides of the vehicle, the ground clearance H, and the tilt angle A, the software simulation data or bench test data are transferred to the correct position, and the calculation is directly performed according to the needs of each evaluation item algorithm, or the optical data is converted into the required projection surface illumination data through the projection method and the inverse square law of distance.

[0317] Based on the parameters of 1.3m left and right low-beam headlight spacing, 1.3m high-beam headlight spacing, 0.85m low-beam ground clearance, 0.85m high-beam ground clearance, -1° low-beam vertical tilt angle, and -1° high-beam vertical tilt angle, determine the lamp installation position and vertical tilt angle, as shown in Table 11. Transfer the optical data to the correct position and perform calculations directly based on the requirements of the evaluation algorithm, or convert the optical data into the required projection surface illuminance data using the projection method and the inverse square law of distance.

[0318] Table 11

[0319] Function X coordinate Y coordinate Z coordinate Vertical tilt angle Low beam (left) 0 0.65m 0.85m -1° Low beam (right) 0 -0.65m 0.85m -1° High beam (left) 0 0.65m 0.85m -1° High beam (right) 0 -0.65m 0.85m -1°

[0320] The algorithm parameter settings for each evaluation item are shown in Table 12.

[0321] Table 12

[0322]

[0323]

[0324]

[0325]

[0326] Table 13

[0327] 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.5 0.5 0.5 0.5 0.5 0.2 0.2 0.2 0.5 1 1 1 0.5 0.2 0.2 0.2 0.5 1 1 1 0.5 0.2 0.2 0.2 0.5 0.5 0.5 0.5 0.5 0.2

[0328] According to the above algorithm, the data values ​​of the measured micro-elements within the measurement range are calculated one by one, and logical judgment is performed, and the corresponding results are returned according to the algorithm.

[0329] The measurement results are calculated and processed to obtain the final results of the evaluation item, as shown in Table 14.

[0330] Table 14

[0331]

[0332] Example 2

[0333] This embodiment proposes a headlamp performance evaluation system. Figure 13 As shown, it includes an illuminance data acquisition module 1, which is configured to obtain illuminance data of the projection surface required by the headlamp to be evaluated;

[0334] Setting module 2, configured to set the measurement element size, measurement orientation and measurement range corresponding to each evaluation index on the required projection surface;

[0335] Parameter data acquisition module 3, configured to calculate parameter data corresponding to the evaluation index according to the illumination value of each measured micro-element;

[0336] The evaluation module 4 is configured to evaluate the performance of the headlamp according to the parameter data.

[0337] The calculation method of each part is as described in Example 1 and will not be repeated here.

[0338] The above embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Any equivalent substitution or modification made by those skilled in the art based on the present invention is within the protection scope of the present invention.

Claims

1. A vehicle headlamp performance evaluation method, characterized by: The evaluation method is specifically as follows: Obtaining the illuminance data of the projection surface required by the headlamp to be evaluated; Set the measurement element size, measurement orientation and measurement range corresponding to each evaluation index on the required projection surface; Calculating parameter data corresponding to an evaluation index based on the illuminance value of each measured microelement, and evaluating headlamp performance based on the parameter data; the evaluation index includes a low-beam index and a high-beam index, the low-beam index including at least one of straight-line guidance distance, curve guidance distance, left-side pedestrian visibility, intersection pedestrian detection width, curve illumination width, luminous flux, and glare to oncoming drivers; the high-beam index including at least one of illumination range, intersection pedestrian detection width, and luminous flux; The method for obtaining parameter data for evaluating the curve lighting width, the intersection pedestrian detection width of the low beam indicator, or the intersection pedestrian detection width of the high beam indicator is as follows: Divide P2 measurement positions in the vertical direction of the required projection surface of the corresponding evaluation index; Calculate the illumination values ​​of all measurement elements one by one within the range of minV to maxV for a certain measurement position. Calculate the exact position of the standard illuminance value slux2 between two adjacent measurement elements in the range of maxV to 0 and in the range of minV to 0 respectively, and then return the distance value at which the light illumination in the range of maxV to 0 and in the range of minV to 0 in the measurement direction reaches the said standard illuminance value slux2 respectively; Obtaining a mean E of the distance values ​​of all measured orientations; When obtaining parameter data for evaluating the lighting range, the corresponding measurement orientation is set to form a spatial angle β with the U direction; minV to maxV represent the minimum and maximum values ​​of the measurement range perpendicular to the desired projection plane, respectively; U direction is the direction of vehicle travel; β represents the solid angle formed by the U direction; The method for obtaining the precise position of the standard illuminance value slux2 between two adjacent measurement elements is as follows: When Lux(k)>slux2 and Lux(k)≠Lux(k-1), restdistk=(cellsize2×(Lux(k)-sLux2)) / (Lux(k)-Lux(k-1)); When Lux(k)=Lux(k-1), restdistk=0.5×cellsize2; If Lux(k-1) is empty, then Lux(k-1)=Lux(k); Lux(k) represents the illuminance of the kth measurement element in the range of maxV to 0 or minV to 0 at the measurement position; k represents a measurement element in the range of maxV to 0 or minV to 0 at the measurement position; cellsize2 is the measurement cell size within the range of maxV to 0 or minV to 0 at the measurement position; slux2 is a standard illumination value for obtaining parameter data of the pedestrian detection width at the intersection, the pedestrian detection width at the intersection of the low beam indicator, or the pedestrian detection width at the intersection of the high beam indicator.

2. The evaluation method according to claim 1, wherein: The method for determining the straight - road guiding distance, curved - road guiding distance, left - side pedestrian visibility, and lighting range is as follows: Divide P1 measurement orientations on the required projection plane of the corresponding evaluation index. When determining the parameter data of the lighting range, the measurement orientation of its corresponding projection plane should form an angle β with the vehicle traveling direction; For a certain measurement orientation within the range from maxU to minU, calculate the illuminance values within all measurement micro - elements one by one, and then calculate the exact position of the standard illuminance value slux1 between two adjacent measurement micro - elements. Then return the distance value at which the light irradiation on this measurement orientation reaches the standard illuminance value; Obtain the mean value D of the distance values of all measurement orientations, and evaluate the straight - road guiding distance, curved - road guiding distance, left - side pedestrian visibility, and lighting range through the mean value D; maxU and minU respectively represent the maximum and minimum values of the measurement range of the required projection plane; The β angle is the solid angle formed with the vehicle traveling direction.

3. The evaluation method according to claim 2, wherein: The method for obtaining the exact position of the calculated standard illuminance value slux1 between two adjacent measurement micro - elements is as follows: When Lux(j)>slux1 and Lux(j)≠Lux(j - 1), restdistj=(cellsize1×(Lux(j)-sLux1)) / (Lux(j)-Lux(j - 1)); When Lux(j1)=Lux(j1 - 1), restdistj = 0.5×cellsize1; If Lux(j - 1) is empty, then Lux(j - 1)=Lux(j); When Lux(j)<slux1, distancej = 0; Lux(j) represents the illuminance of the j - th measurement micro - element; cellsize1 is the size of the measurement micro - element when obtaining the straight - road guiding distance, curved - road guiding distance, left - side pedestrian visibility, or lighting range; slux1 is the standard illuminance value when obtaining the straight - road guiding distance, curved - road guiding distance, left - side pedestrian visibility, or lighting range; restdistj represents the exact position of the standard illuminance value slux1 between two adjacent measurement micro - elements at a certain measurement orientation when obtaining the straight - road guiding distance, curved - road guiding distance, left - side pedestrian visibility, or lighting range; 4. The evaluation method according to claim 3, wherein: The method for obtaining the mean value D of the distance values of all measurement orientations is as follows: Among them, when Lux(j)>slux1, the method for obtaining the distance value at which the light irradiation of the straight - road guiding distance, left - side pedestrian visibility, or lighting range reaches the standard illuminance value slux1 is: distancej = maxU - cellsize1×j+restdistj, The method for obtaining the curved - road guiding distance is: distancej = maxU - cellsize1×j+restdistj+s×tanα; Among them, distancej represents the distance value at which the light irradiation of a certain measurement orientation for obtaining the straight - road guiding distance, left - side pedestrian visibility, curved - road guiding distance, or lighting range reaches the standard illuminance value slux1; s represents the offset of the starting position of the center line of the oncoming lane; α represents the angle between the calculated measurement azimuth and the driving direction; n1 represents the number of measurement elements of a certain measurement azimuth; 5. The evaluation method according to claim 1, wherein: The method for obtaining the mean value E of the distance values of all measurement azimuths is distancek = |distance(max)| + |distance(min)| When Lux(k) > slux2; distance(max) or distance(min) = maxW - cellsize2 × k + restdistk; When Lux(k) < slux2, distance(max) or distance(min) = 0; where distancek represents the distance value at which the light irradiation on the first side of the center line of the road reaches the illuminance of sLux2 in a certain measurement azimuth; n2 represents the number of measurement elements within the range from maxV to 0 or from minV to 0 in this measurement azimuth; maxW represents the maximum value of the measurement range on the required projection plane; 6. The evaluation method according to claim 1, wherein: The method for obtaining the parameter data of the luminous flux for evaluating the low beam index, the dazzling of oncoming drivers or the luminous flux of the high beam index is: On the corresponding required projection plane, successively calculate the illuminance values of all measurement elements within the range enclosed by maxY to minY and maxZ to minZ; For evaluating the dazzling of oncoming drivers, after obtaining the illuminance values within all the measurement elements, multiply them by the weight values of the corresponding divided regions and then accumulate; For evaluating the luminous flux of the low beam index or the luminous flux of the high beam index, after obtaining the illuminance values within all the measurement elements, accumulate them; where: maxY to minY respectively represent the maximum and minimum values of the measurement range in the horizontal direction of the required projection plane for evaluating the luminous flux of the low beam index, the dazzling of oncoming drivers or the luminous flux of the high beam index; maxZ to minZ respectively represent the maximum and minimum values of the measurement range in the vertical direction of the required projection plane for evaluating the luminous flux of the low beam index, the dazzling of oncoming drivers or the luminous flux of the high beam index.

7. The evaluation method according to claim 1, wherein: The data read on the required projection plane is obtained by converting optical data through the projection method and the inverse square law of distance according to the parameters of the distance W between the low beam or high beam on the left and right sides of the vehicle, the ground clearance H, and the tilt angle A.

8. A vehicle headlamp performance evaluation system based on the evaluation method according to any one of claims 1 - 7, characterized in that: It includes: An illuminance data acquisition module configured to acquire the illuminance data of the required projection plane of the headlamp to be evaluated; A setting module configured to set the measurement element size, measurement azimuth, and measurement range corresponding to each evaluation index on the required projection plane; A parameter data acquisition module configured to calculate the parameter data of the corresponding evaluation index according to the illuminance value of each measurement element; An evaluation module configured to evaluate the performance of the headlamp based on the parameter data.

9. A computer-readable medium, characterized in that: Computer-readable instructions are stored thereon, and when the computer-readable instructions are executed by a processor of a computer, the computer is caused to execute the method according to any one of claims 1 to 7.

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