CN103954234A - Self-calibration measuring algorithm for vehicle outline and wheel base automatic measuring system - Google Patents

Abstract

The invention discloses a self-calibration measuring algorithm for a vehicle outline and wheel base automatic measuring system. The self-calibration measuring algorithm includes the first step of measuring system data, the second step of starting up the system and enabling distance measuring units to conduct geodetic calibration, obtain calibration parameters and transmit the calibration parameters to a comprehensive data processing unit, and the third step of measuring a vehicle to be measured, transmitting data and calculating the vehicle outline and the wheel base. Through the self-calibration measuring algorithm for the vehicle outline and wheel base automatic measuring system, the vehicle outline data including the length, width and height of the vehicle and the wheel base data of the vehicle can be automatically measured, the measuring accuracy is guaranteed, and the measuring efficiency is improved.

Description

A self-calibration measurement algorithm for an automatic vehicle profile and wheelbase measurement system

technical field

The invention relates to the measurement field, in particular to a self-calibration measurement algorithm of a vehicle profile and wheelbase automatic measurement system.

Background technique

With the rapid development of the economy, the number of new motor vehicles in our country is astonishing every year. In order to prevent some passenger and trucks from modifying the vehicle size without permission, the Vehicle Management Office of the Traffic Management Bureau of the Ministry of Public Security must inspect the outer contour size of the vehicles every year. The traditional manual measurement method currently used has low efficiency and high labor cost, and is affected by the complex structure of the vehicle under test and restricted by the measurement tools, so the measurement accuracy has a large error. This urgently requires the use of automatic methods and automatic devices to detect the outer contour of the vehicle, which not only ensures the measurement accuracy, but also improves the measurement efficiency.

In order to realize the automatic monitoring of vehicle size measurement, some automatic measurement methods and devices have also been developed in recent years. At present, it has been found out from the existing vehicle detection methods and device-related materials and related patent materials that the current measurement devices for vehicle size detection mainly include Laser scanners, lidar, imaging devices, light curtain sensor arrays, etc. The Chinese patent with the application number 201210119598.7 discloses a light curtain-based automatic vehicle size measurement system and its measurement method. The system requires multiple light curtain sensor arrays, which has a complex structure and high power consumption. Damage, not easy to detect and repair later. The Chinese patent application number 201020645084.1 discloses a vehicle size automatic inspection and measurement device using a laser scanner and an imaging device. The device is mainly based on an imaging device and supplemented by a laser scanner. Affected by complex backgrounds, light and shadows, the work is unstable. The Chinese patent with application number 201210175516.0 discloses a method and device for measuring vehicle size by laser radar scanning, which has the following disadvantages: (1) the wheelbase of the vehicle cannot be detected; (2) the pair of vehicle rearview mirrors cannot be removed The influence of width; (3) Due to the limitation of the installation position of the radar, there is a dead angle in the scanning of the vehicle width, and the measured vehicle width is only the width of the upper surface of the vehicle, not necessarily the maximum width of the vehicle. (4) This method cannot meet the accuracy requirements of the novelty checking project of this application. In short, the existing automatic vehicle size measurement methods and devices have high cost, incomplete performance and low usability.

Contents of the invention

In order to overcome the technical problems in the prior art, the present invention provides a self-calibration measurement algorithm of an automatic vehicle profile and wheelbase measurement system.

A vehicle profile and wheelbase self-calibration measurement algorithm, comprising the following steps:

Step 1, before starting the system, measure the width L6 and height L7 of the arch at the proximal end;

Step 2, start the system, the second laser radar of the second distance measurement unit and the third laser radar of the third distance measurement unit automatically perform geodesic correction, and obtain the correction parameters and transmit them to the integrated data processing unit, and the integrated data processing unit calculates and obtains The second laser radar standard angle α1 and the third laser radar standard angle α2;

Step 3, the vehicle under test enters the detection channel, triggers the contour measurement control unit and the wheelbase measurement control unit respectively, the contour measurement control unit sends a signal to the first distance measurement unit, the wheelbase measurement control unit sends a signal to the first distance measurement unit, The first distance measurement unit scans the vehicle according to the trigger signal to obtain the relevant parameters of the vehicle; the second distance measurement unit and the third distance measurement unit scan the vehicle to obtain the relevant parameters of the vehicle; the three distance measurement units transmit the obtained vehicle parameters to the integrated system in real time data processing unit;

Step 4, the vehicle drives out of the detection channel, the parameters obtained by the three distance measurement units are transmitted to the comprehensive data processing unit, and the comprehensive data processing unit calculates the vehicle profile and wheelbase data according to the relevant parameters obtained in steps 1 to 3.

Compared with the prior art, the present invention has significant advantages in that: (1) the technical scheme is simple in structure, consisting of 3 distance sensors and 2 groups of measuring sensors, with convenient installation location and easy maintenance; (2) the measured vehicle only needs It only needs to pass through the detection channel at low speed without stopping. The measurement result can be obtained after the vehicle completely passes through the detection channel. The entire detection time will not exceed 30 seconds. Compared with manual measurement, it greatly saves labor costs and improves time efficiency;( 3) Use two laser radars installed at different heights to achieve accurate measurement of the height and width of vehicles at different heights without dead angle; (4) Use the laser radar installed directly in front of the front of the vehicle to accurately measure the wheelbase of the moving vehicle; (5) Utilize the histogram principle to filter and eliminate interference data based on convex sampling points, which can eliminate the interference of data such as reflectors in the process of vehicle width measurement; (6) The measurement accuracy has passed error analysis and experimental testing to ensure installation accuracy When the requirements are met, the measurement error of each value can be controlled within 1%.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is a schematic diagram of the overall framework of the system of the present invention;

Fig. 3 is a schematic diagram of vehicle length measurement;

Figure 4 is a schematic diagram of the standard angle of the laser radar geodesic correction before the vehicle width and height measurement;

Fig. 5 is a schematic diagram of vehicle width and vehicle height measurement;

Figure 6 is a schematic diagram of wheelbase measurement.

Detailed ways

The vehicle profile and wheelbase automatic measurement system and measurement method provided by the present invention will be described in detail below in conjunction with the accompanying drawings. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention.

An automatic vehicle profile and wheelbase measurement system, comprising three distance measurement units, a profile measurement control unit, a wheelbase measurement control unit, a evidence collection unit, a comprehensive data processing unit, and a detection channel; the detection channel consists of a near-end arch Composed of the remote arch frame, the two arch frames are parallel and perpendicular to the horizontal plane, the distance measurement unit, the contour measurement control unit, the wheelbase measurement control unit, and the evidence collection unit are arranged on the detection channel; the three distance measurement units are respectively It is the first distance measurement unit B1, the second distance measurement unit B2 and the third distance measurement unit B3, the contour measurement control unit is connected with the first distance measurement unit B1, and the wheelbase measurement control unit is connected with the first distance measurement unit B1 connection, the distance measurement unit is connected with the comprehensive data processing unit, and the comprehensive data processing unit is also connected with the second distance measurement unit B2 and the third distance measurement unit B3 respectively, and the forensic unit monitors and records the real-time status of the vehicle operation detection.

Specifically, the three distance measurement units are respectively the first distance measurement unit B1, the second distance measurement unit B2 and the third distance measurement unit B3, and the first distance measurement unit B1 is installed in the center of the far-end arch beam , the second distance measuring unit B2 and the third distance measuring unit B3 are installed on the two columns of the near-end arch frame at different heights to achieve accurate measurement of the height and width of vehicles of different heights, for example, in actual measurement , the farther the measurement unit is from the vehicle under test, the lower the accuracy. If the second distance measurement unit B2 and the third distance measurement unit B3 are located at the same height, it is difficult to meet the measurement requirements of large vehicles and small and medium-sized vehicles at the same time. If they are at different heights, When measuring small and medium-sized vehicles, the distance from the measuring unit to the ground is closer to the measured vehicle, and the measured data is more accurate. When measuring large vehicles, the distance from the measuring unit to the ground is higher, and the measured data is more accurate. ; Generally, the vehicle height of small and medium-sized vehicles is between 1.5 meters and 2 meters, so the lower distance measurement unit from the ground is fixed and the near-end arch column is 3 meters from the ground, while the height of large vehicles is generally more than 3 meters Therefore, the distance measurement unit higher than the ground is fixed at a distance of 3.5 meters from the ground at the proximal end of the arch column. Each distance measurement unit includes a laser radar and a distance measurement front-end processor, the data transmission end of the distance measurement front-end processor is connected to the laser radar, and the transmitter end of the distance measurement front-end processor is connected to the comprehensive data processing unit, the first The receiving end of the first distance measurement front-end processor of the distance measurement unit B1 is connected with the contour measurement control unit and the wheelbase measurement control unit. Wherein, the lidar adopts a single-line lidar, and the radar emits multiple scan lines in one frame. When the scan line scans an obstacle, the lidar receives the signal reflected by the scan line and can measure the distance between the radar and the obstacle. The length of the scan line and the angle between the scan line and the ground normal vector (downward direction). The distance measurement front-end processor can be an embedded development board embedded in the laser radar or other devices with functions of calculation and sending and receiving signals, the distance measurement front-end processor and the comprehensive data processing unit, the contour measurement control unit and the wheelbase measurement control unit The connection method can be a wireless connection or a wired connection. Through this installation method, the first distance measurement front-end processor can transmit the trigger signal of the contour measurement control unit or the wheelbase measurement control unit to the laser radar to start the laser radar. Or stop scanning and transmit the parameters obtained by the lidar scanning to the comprehensive data processing unit for data calculation.

The profile measurement control unit includes a group of profile measurement sensors and a profile measurement front-end processor, the profile measurement sensor is composed of two photocells, one photocell is the first sending end, and the other photocell is the first receiving end end, the first transmitting end of the profile measurement sensor is located in the center of the arch beam at the proximal end, the first receiving end of the profile measurement sensor is located at the projection position of the first transmitting end of the profile measurement sensor on the horizontal plane, and the data transmission end of the profile measurement front-end processor is connected with the profile measurement The first sending end of the sensor is connected, and the sending end of the profile measurement front-end processor is respectively connected with the receiving ends of the distance measurement front-end processors of the three distance measuring units. Wherein, the profile measurement front-end processor can be an embedded development board embedded in the first transmitting end of the profile measurement sensor, and the connection mode between the profile measurement front-end processor and the distance measurement front-end processor receiving end of the distance measurement unit can be a wireless connection, It can also be a wired connection. With this installation method, when the vehicle triggers the profile measurement sensor, the profile measurement front-end processor transmits a signal to the distance measurement unit to control the lidar to start or stop scanning the vehicle.

As an improvement of the present invention, the profile measurement control unit is respectively connected with the second distance measurement unit B2 and the third distance measurement unit B3, specifically, the second distance measurement front-end processor receiving end of the second distance measurement unit B2 is connected with the profile The measurement control unit is connected, and the receiving end of the third distance measurement front-end processor of the third distance measurement unit B3 is connected with the contour measurement control unit. This connection makes it possible for the scanning of the second distance measuring unit B2 and the third distance measuring unit B3 to start when the vehicle activates the contour control unit.

The wheelbase measurement control unit consists of a set of wheelbase measurement sensors and a wheelbase measurement front-end processor. The wheelbase measurement sensor is composed of two photocells, one photocell is the second sending end, and the other photocell is the second At the receiving end, the second sending end of the wheelbase measurement sensor is installed on the side of the column of the near-end arch, and the second receiving end of the wheelbase measurement sensor is installed in the middle of the detection channel and close to the position of the near-end arch. The two receiving ends, the first distance measuring unit B1, and the profile measuring sensor form a plane, which is perpendicular to the horizontal plane; the data transmission end of the wheelbase measuring front-end processor is connected to the second sending end of the wheelbase measuring sensor, and the wheelbase is measured The sending end of the front-end processor is connected with the receiving end of the distance measuring front-end processor of the first distance measuring unit. Wherein, the wheelbase measurement front-end processor can be an embedded development board embedded in the first sending end of the wheelbase measurement sensor, and the connection mode between the wheelbase measurement front-end processor and the distance measurement front-end processor receiving end of the first distance measurement unit It can be a wireless connection or a wired connection. With this installation method, when the vehicle wheel triggers the wheelbase measurement sensor, the wheelbase measurement front-end processor transmits the signal to the first distance measurement unit to control the first laser radar to start or Stop scanning vehicles.

The forensics unit is composed of multiple cameras, which monitor and record the real-time status of the vehicle running detection. In the present invention, the forensics unit is composed of four cameras, which are respectively A1, A2, A3, and A4, which are respectively arranged on the near-end arch beam Close to the central position, the far-end arch frame is close to the central position, and the near-end arch frame is the upper end of the two columns.

The comprehensive data processing unit is generally a computer with computing functions, which is used to receive the data scanned by each distance measuring unit and calculate the precise value of the vehicle profile and wheelbase through the program element.

A vehicle profile and wheelbase self-calibration measurement algorithm, the measurement algorithm includes the following steps:

Step 1, before starting the system, measure the width L6 and height L7 of the arch at the proximal end;

Step 2, start the system, the second laser radar of the second distance measurement unit B2 and the third laser radar of the third distance measurement unit B3 automatically perform geodesic correction, and obtain correction parameters and transmit them to the integrated data processing unit, the integrated data processing unit Calculate the second laser radar standard angle α1 and the third laser radar standard angle α2;

Step 3, the vehicle under test enters the detection channel, triggers the contour measurement control unit and the wheelbase measurement control unit respectively, the contour measurement control unit sends a signal to the first distance measurement unit B1, and the wheelbase measurement control unit sends a signal to the first distance measurement unit B1 signal, the first distance measurement unit B1 scans the vehicle according to the trigger signal to obtain the relevant parameters of the vehicle; the second distance measurement unit B2 and the third distance measurement unit B3 scan the vehicle to obtain the relevant parameters of the vehicle; the three distance measurement units will obtain the vehicle The parameters are transmitted to the comprehensive data processing unit in real time;

Step 4, the vehicle drives out of the detection channel, the parameters obtained by the three distance measurement units are transmitted to the comprehensive data processing unit, and the comprehensive data processing unit calculates the vehicle profile and wheelbase data according to the relevant parameters obtained in steps 1 to 3.

In step 2, the second laser radar geodesic correction method to obtain the second laser radar standard angle α1 is as follows: firstly, the second laser radar emits a scan line of one frame to scan the detection channel when there is no vehicle under test for geodesic correction, and the second laser radar The data of the length of the scanning line between the laser radar and the ground and the angle between the scanning line and the normal vector of the horizontal plane (direction downward) are transmitted to the integrated data processing unit; then the integrated data processing unit is selected to be distributed on both sides of the center line of the detection channel The two scan lines and their angles with the normal vector of the horizontal plane (direction downward), the scan line with a larger angle with the normal vector of the horizontal plane (direction downward) is defined as the second laser radar reference line M1, and the other is the second laser radar auxiliary line M2, the angle between M1 and the normal vector of the horizontal plane (direction downward) is defined as β1, and the angle between M2 and the normal vector of the horizontal plane (direction downward) is defined as β2; then calculate the second laser radar standard angle α1

$\mathrm{<span\; class="notranslate">\; \&alpha;</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; arccos</span>}\frac{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; cos</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&beta;</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; \&beta;</span>}\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>}{\sqrt{{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; \&CenterDot;</span>\mathrm{<span\; class="notranslate">\; cos</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&beta;</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; \&beta;</span>}\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>}}<span\; class="notranslate">\; ;</span>$

In step 2, the third lidar geodesic correction method to obtain the standard angle α2 of the third lidar is as follows: firstly, the third lidar emits a scan line of one frame to scan the detection channel when there is no vehicle under test, and the third lidar The data of the length of the scanning line between the ground and the angle between the scanning line and the normal vector of the horizontal plane (direction downward) are transmitted to the integrated data processing unit; then the integrated data processing unit selects two The scanning line and its angle with the normal vector of the horizontal plane (direction downward), and the scan line ratio with a larger angle with the normal vector of the horizontal plane (direction downward) are defined as the third lidar reference line M3, and the other is the first laser radar reference line M3. The angle between the three laser radar auxiliary lines M4, M3 and the normal vector of the horizontal plane (direction downward) is defined as β3, and the angle between M4 and the normal vector of the horizontal plane (direction downward) is defined as β4; then calculate the standard angle of the third laser radar α2

$\mathrm{<span\; class="notranslate">\; \&alpha;</span>}\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; arccos</span>}\frac{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; \&CenterDot;</span>\mathrm{<span\; class="notranslate">\; cos</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&beta;</span>}\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; \&beta;</span>}\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>}{\sqrt{{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; 3</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; 4</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; cos</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&beta;</span>}\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; \&beta;</span>}\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>}}<span\; class="notranslate">\; ;</span>$

Scanning and measuring the vehicle in step 3 includes vehicle length measurement, vehicle width measurement, vehicle height measurement and vehicle wheelbase measurement;

In the vehicle length measurement, the head of the vehicle under test passes the near-end arch frame on the measurement channel, the vehicle head triggers the contour measurement control unit, and the contour measurement control unit sends a signal to the first distance measurement unit B1, and the first distance measurement unit B1 The first laser radar emits a scan line of one frame to scan the vehicle and acquires parameters, including the length D1 _h of the scan line between the first distance laser radar and the vehicle head when the vehicle head triggers the profile measurement control unit and the distance between the scan line and the ground The included angle θ1 _h of the vector (direction downward), the value range of h is the number of scanning lines that the first laser radar emits in one frame when the vehicle head triggers the contour measurement control unit; when the vehicle tail passes the near end on the measurement channel The arch frame, the rear of the vehicle triggers the contour measurement control unit, the contour measurement control unit sends a signal to the first distance measurement unit B1, and the first laser radar in the first distance measurement unit B1 emits a scan line of one frame to scan the vehicle and obtain parameters, including When the tail of the vehicle triggers the profile measurement control unit, the length D2 _i of the scanning line between the first lidar and the vehicle head and the angle θ2 _i between the scanning line and the normal vector (downward direction) of the ground, the value range of i is the vehicle When the tail triggers the contour measurement control unit, the first lidar emits the number of scanning lines of one frame to scan the vehicle and obtain parameters;

The vehicle height and vehicle width are measured at the same time. During the measurement process, the measured vehicle enters the near-end arch frame of the detection channel, the second distance measurement unit B2 with different heights on both sides, the second laser radar emission scan line and the third distance measurement unit B3. The three laser radars emit scanning lines to scan the vehicle signal. When the rear of the vehicle crosses the near-end arch frame of the detection channel, the second distance measurement unit B2 and the second distance measurement unit B3 complete the scanning of the vehicle. The parameters obtained during this process include: : The length D3 _(j,k) of the scan line between the second lidar and the vehicle and the length D4 _(m,n) of the scan line between the third lidar and the vehicle, and the distance between the scan line emitted by the second lidar and the ground The angle θ3 _(j,k) between the normal vector (direction downward) of the normal vector (direction downward) and the angle θ4 _(m,n) between the scanning line emitted by the third lidar and the normal vector (direction downward) of the ground, where j is taken as The value range is the number of scan lines that the second laser radar emits in one frame, the value range of k is the number of frames emitted by the second laser radar, and the value range of m is the number of scan lines that the third laser radar emits in one frame, The value range of n is the number of frames emitted by the third lidar;

In the vehicle wheelbase measurement, when the first group of wheels of the vehicle under test passes the wheelbase measurement control unit, the wheelbase measurement is triggered, and the wheelbase measurement control unit sends a signal to the first distance measurement unit B1, and the first distance measurement unit B1 The laser radar emits a scan line of one frame to scan the vehicle and obtain parameters, including the length D5 _x of the scan line between the first laser radar and the vehicle head when the first group of wheels triggers the wheelbase measurement control unit and the normal vector between the scan line and the ground The included angle θ5 _x , the value range of x is the number of scanning lines of one frame emitted by the first lidar when the first group of wheels of the vehicle triggers the wheelbase measurement control unit; thereafter, for each trigger signal of the wheels, the first distance The measurement unit B1 scans the vehicle under test, and obtains the parameters of the last group of wheels passing the wheelbase measurement control unit, including the scanning line between the first laser radar and the vehicle head when the last group of wheels triggers the wheelbase measurement control unit The length D6 _y and the angle θ6 _y between the scan line and the normal vector (downward direction) of the ground, the value range of y is the scan line of the first laser radar emitting a frame when the last group of wheels of the vehicle triggers the wheelbase measurement control unit quantity.

The specific calculation process of the comprehensive data processing unit in step 4 is:

The calculation method of the vehicle length: firstly, the integrated data processing unit selects the scanning line with the shortest projection on the horizontal plane among the scanning lines emitted by the first laser radar in the first distance measuring unit B1 when the front of the vehicle triggers the contour measurement control unit, and is denoted as D1 _min , where The included angle with the ground normal vector (downward direction) is denoted as θ1 _min . The specific method is as follows: the integrated data processing unit calculates the projection distance of the scanning line emitted by the first laser radar on the horizontal plane K1 _h = D1 _h × sinθ1 _h , and selects the smallest K1 The scan line corresponding to _h is denoted as D1 _min ; when the rear of the vehicle triggers the contour measurement control unit, the first laser radar in the first distance measurement unit B1 emits a frame of scan lines, and the scan line with the shortest horizontal plane projection is denoted as D2 _min , where The included angle (downward direction) with the ground normal vector is recorded as θ2 _min , the specific method is: the integrated data processing unit calculates the projection distance of the scan line emitted by the first lidar on the horizontal plane K2 _i = D2 _i × sinθ2 _i , and selects the smallest K2 The scanning line corresponding to _i is recorded as D2 _min ; calculate the vehicle length $L_l=\sqrt{{{\mathrm{D.}1}_{\min }}^2+{{\mathrm{D.}2}_{\min }}^2-2\&CenterDot;{\mathrm{D.}1}_{\min }\&Center\; Dot;{\mathrm{D.}2}_{\min }\&CenterDot;\cos ({\mathrm{\&theta;}1}_{\min }-{\mathrm{\&theta;}2}_{\min })};$

Calculation method of vehicle width: Correct the D3 _(j,k) and θ3 _(j,k) measured by the second laser radar with the standard angle α1 of the second laser radar to obtain the distance of each scanning line emitted by the second laser radar on the ground projection length

W1 _(j,k) = D3 _(j,k) cos(θ3 _(j,k) -β1-α1);

Correct the D4 _{(m, n)} and θ4 _{(m, n)} measured by the third laser radar with the third laser radar standard angle α2 to obtain the projection length of each scan line emitted by the third laser radar on the ground

W2 _(m,n) = D4 _(m,n) cos(θ4 _(m,n) -β3-α2);

Then select the minimum value L4=min{W1 _(j,k) } and L5=min{W2 ( _{m ,n) } from W1 (j,k)} and W2 _(m,n) ; finally calculate the vehicle width L _w =L6 -L4-L5;

Calculation method of vehicle height: Calculate the height of the second laser radar from the ground L31=M1×sinα1 according to the second laser radar standard angle α1 and the second laser radar reference line M1, according to the third laser radar standard angle α2 and the third laser radar Base line M3 calculates the height of the second lidar from the ground L32=M3×sinα2; D3 _(j,k) and θ3 _(j,k) measured by the second lidar are corrected with the second lidar standard angle α1 to obtain the second The projection length of each scanning line emitted by the laser radar perpendicular to the ground is H1=D3 _(j,k) sin(θ3 _(j,k) -β1-α1), and the D4 _{(m,n )} and θ4 _{(m, n)} are corrected with the third lidar standard angle α2 to obtain the projection length of each scanning line emitted by the second lidar perpendicular to the ground H2=D4 _(m,n) sin(θ4 _{(m, n)} -β3-α2); Calculate the vehicle height L _h1 =L31+H1 obtained by using the data measured by the second laser radar, calculate the vehicle height L _h2 =L32+H2 obtained by using the data measured by the third laser radar, from L Select the larger value from _h1 and L _h2 as the vehicle height L _h = max{L _h1 , L _h2 }; the calculation method of the vehicle length: first, the comprehensive data processing unit selects the first group of wheels when triggering the wheelbase measurement control unit. In the distance measurement unit B1, the scan line of the first lidar emitting one frame is the shortest scan line projected on the horizontal plane, which is denoted as D5 _min , and the angle between it and the normal vector of the horizontal plane is denoted as θ5 _min . The specific method is: the comprehensive data processing unit calculates the first The projection distance of the scanning line emitted by a laser radar on the horizontal plane is K5 _x = D5 _x × sinθ5 _x , and the scanning line corresponding to the smallest K5 _x is selected as D5 _min ; the first distance measurement is performed when the last group of wheels is selected to trigger the wheelbase measurement control unit In unit B1, the first laser radar emits the scan line of one frame and the shortest horizontal plane projection scan line is denoted as D6 _min , and the angle between it and the normal vector of the horizontal plane is denoted as θ6 _min . The specific method is: the integrated data processing unit calculates the first laser The projection distance of the scan line emitted by the radar on the horizontal plane is K6 _y = D6 _y × sinθ6 _y , select the scan line corresponding to the smallest K6 _y and record it as D6 _min ; calculate the vehicle length $L_{\mathrm{wb}}=\sqrt{{{\mathrm{D.}5}_{\min }}^2+{{\mathrm{D.}6}_{\min }}^2-2\&Center\; Dot;{\mathrm{D.}5}_{\min }\&CenterDot;{\mathrm{D.}6}_{\min }\&Center\; Dot;\cos ({\mathrm{\&theta;}5}_{\min }-{\mathrm{\&theta;}6}_{\min })}.$

Claims (9)

1. A vehicle profile and wheelbase automatic measurement system is characterized in that: the system comprises three distance measurement units, a profile measurement control unit (C), a wheelbase measurement control unit (D), a evidence collection unit, and a comprehensive data processing unit and a detection channel; the detection channel is composed of a near-end arch frame and a far-end arch frame, the two arch frames are parallel and perpendicular to the horizontal plane, the distance measurement unit, the contour measurement control unit, the wheelbase measurement control unit, The forensics unit is arranged on the detection channel; the three distance measurement units are respectively the first distance measurement unit (B1), the second distance measurement unit (B2) and the third distance measurement unit (B3), and the contour measurement control unit and The first distance measurement unit (B1) is connected, the wheelbase measurement control unit is connected with the first distance measurement unit (B1), the distance measurement unit is connected with the comprehensive data processing unit, and the comprehensive data processing unit is also respectively connected with the second distance measurement unit (B2 ) is connected with the third distance measuring unit (B3), and the described forensic unit monitors and records the real-time status of the vehicle running detection. 2. The vehicle profile and wheelbase automatic measurement system according to claim 1, characterized in that: the first distance measurement unit (B1) is installed in the center of the arch beam at the far end, and the second distance measurement unit (B2) and the third distance measuring unit (B3) are installed on the two columns of the near-end arch with different heights, and each distance measuring unit includes a laser radar and a distance measuring front-end processor, and the distance measuring front-end processor The data transmission end is connected with the laser radar, the transmitter end of the distance measurement front-end processor is connected with the comprehensive data processing unit, and the first distance measurement front-end processor receiver end of the first distance measurement unit (B1) is respectively connected with the contour measurement control unit (C) and the contour measurement control unit (C) and The wheelbase measurement control unit (D) is connected. 3. The vehicle profile and wheelbase automatic measurement system according to claim 2, characterized in that: the profile measurement control unit (C) comprises a group of profile measurement sensors and a profile measurement front-end processor, and the profile measurement sensors include the first A sending end and a first receiving end, the first sending end of the profile measurement sensor is located in the center of the arch beam at the proximal end, the first receiving end of the profile measurement sensor is located at the projection position of the first sending end of the profile measurement sensor on the horizontal plane, and the front-end processing of the profile measurement The data transmission end of the sensor is connected with the first sending end of the profile measuring sensor, and the sending end of the front-end processor of the profile measuring is connected with the receiving end of the distance measuring front-end processor of the first distance measuring unit (B1). 4. The vehicle profile and wheelbase automatic measurement system according to claim 2, characterized in that: the wheelbase measurement control unit (D) comprises a group of wheelbase measurement sensors and a wheelbase measurement front-end processor, the wheelbase The measurement sensor includes a second sending end and a second receiving end. The second sending end of the wheelbase measuring sensor is installed on the side of the column of the near-end arch frame, and the second receiving end of the wheelbase measuring sensor is installed in the middle of the detection channel and close to the near-end arch frame. position, the second receiving end of the wheelbase measurement sensor, the first distance measurement unit (B1), and the profile measurement sensor form a plane, which is perpendicular to the horizontal plane; The second sending end of the distance measuring sensor is connected, and the sending end of the wheelbase measuring front-end processor is connected with the receiving end of the distance measuring front-end processor of the first distance measuring unit. 5. A vehicle profile and wheelbase automatic measurement algorithm, is characterized in that, measurement algorithm comprises the following steps: Step 1, measure the relevant parameters of the system, The distance parameters between each unit of the measurement system and the detection channel include: the shortest projection length L1 of the distance on the horizontal plane between the first laser radar in the first distance measurement unit (B1) and the contour measurement sensor of the contour measurement control unit; Two distance measuring units (B2) are apart from the vertical distance L31 of the ground; The third distance measuring unit (B3) is apart from the vertical distance L32 of the ground; The width L6 and the height L7 of the proximal arch frame; Step 2, start the system, obtain the laser radar measurement information when there is no vehicle in the measurement channel, The second distance measurement unit B2 and the third distance measurement unit B3 start to scan after the system is started, and obtain the laser radar measurement information when there is no vehicle in the measurement channel; Step 3, scan and measure the vehicle and obtain parameters, and transmit the obtained parameters to the integrated data processing unit, When the vehicle enters the detection channel, the contour measurement control unit and the wheelbase measurement control unit are respectively triggered, the contour measurement control unit sends a signal to the first distance measurement unit (B1), and the wheelbase measurement control unit sends a signal to the first distance measurement unit (B1) , the first distance measuring unit (B1) scans the vehicle according to the trigger signal to obtain relevant parameters of the vehicle; when the vehicle enters the detection channel, the second distance measuring unit (B2) and the third distance measuring unit (B3) scan the vehicle to obtain relevant parameters of the vehicle; The three distance measurement units transmit the obtained vehicle parameters to the comprehensive data processing unit in real time; Step 4, calculate the contour and wheelbase data of the vehicle, After the vehicle leaves the detection channel, the parameters obtained by the three distance measurement units are transmitted to the comprehensive data processing unit, and the comprehensive data processing unit calculates the vehicle profile and wheelbase data according to the relevant parameters obtained in steps 1 and 3. 6. The vehicle profile and wheelbase automatic measurement algorithm according to claim 5, characterized in that: the scanning and measuring vehicle in step 3 includes vehicle length measurement, vehicle width measurement, vehicle height measurement and vehicle wheelbase measurement; In the vehicle length measurement, the measured vehicle passes the entrance on the measurement channel, and the vehicle covers the contour measurement sensor. When the rear of the vehicle passes the contour measurement sensor, a trigger signal is given to the first distance measurement unit (B1). At this time, the first distance measurement unit ( The first laser radar in B1) scans the vehicle by emitting a scanning line, and the obtained parameters include: the length D1 _i of a scanning line emitted by scanning a frame between the first laser radar and the vehicle head when the rear of the vehicle passes over the profile measurement sensor and the angle θ1 _i between the scan line and the normal vector of the ground, the value range of i is the number of scan lines emitted by the first lidar scanning a frame when the rear of the vehicle passes the profile measurement sensor; In the vehicle width measurement, the vehicle under test enters the near-end arch frame of the detection channel, the second distance measurement unit (B2) and the third distance measurement unit (B3) of different heights on both sides scan the vehicle signal, and the second distance measurement unit (B2 The second laser radar in ) and the third laser radar in the third distance measurement unit (B3) emit scan lines to scan the vehicle. ) and the second distance measurement unit (B3) to complete the scanning of the vehicle, the parameters obtained in this process include: the length D2 _{(j, k)} of a scanning line emitted by scanning a frame between the second laser radar and the vehicle The included angle θ3 _(m,n) between the scan line and the normal vector of the ground, and the length D3 _(m,n) of a scan line emitted by scanning a frame between the third lidar and the vehicle and the scan line The included angle θ3 _(m,n) with the normal vector of the ground, where the value range of j is the number of scanning lines emitted by the second laser radar scanning a frame, and the value range of k is the frame scanned by the second laser radar Number, the value range of m is the number of scanning lines emitted by the third laser radar scanning one frame, and the value range of n is the number of frames scanned by the third laser radar; In the vehicle height measurement, the vehicle under test enters the near-end arch frame of the detection channel, the second distance measurement unit (B2) and the third distance measurement unit (B3) of different heights on both sides scan the vehicle signal, and the second distance measurement unit (B2 The second laser radar in ) and the third laser radar in the third distance measurement unit (B3) emit scan lines to scan the vehicle. ) and the second distance measurement unit (B3) to complete the scanning of the vehicle, the parameters obtained in this process include: the length D2 _{(j, k)} of a scanning line emitted by scanning a frame between the second laser radar and the vehicle The included angle θ3 _(m,n) between the scan line and the normal vector of the ground, and the length D3 _(m,n) of a scan line emitted by scanning a frame between the third lidar and the vehicle and the scan line The included angle θ3 _(m,n) with the normal vector of the ground, where the value range of j is the number of scanning lines emitted by the second laser radar scanning a frame, and the value range of k is the frame scanned by the second laser radar Number, the value range of m is the number of scanning lines emitted by the third laser radar scanning one frame, and the value range of n is the number of frames scanned by the third laser radar; When the first group of wheels of the vehicle under test pass the wheelbase measurement control unit in the vehicle wheelbase measurement, the wheelbase measurement is triggered, and the wheelbase measurement control unit sends a signal to the first distance measurement unit (B1), and the first distance measurement unit (B1) The first laser radar emission scan line in the vehicle scans the vehicle, and thereafter, for each trigger signal of the wheel, the first distance measurement unit (B1) scans the vehicle under test, and the obtained parameters include: the first laser radar and the vehicle head The length D4 _{(x, y)} of a scan line emitted by scanning a frame and the angle θ4 _{(x, y)} between the scan line and the normal vector of the ground, the value range of x is the first laser radar scan The number of scanning lines transmitted in one frame, and the value range of y is the number of times the wheel passes the wheelbase measurement control unit. 7. The vehicle profile and wheelbase automatic measurement algorithm according to claim 6, characterized in that: the specific calculation process of the integrated data processing unit in step 4 is: Calculation method of vehicle length: first calculate the projected distance between the first lidar and the vehicle on the ground K1 _i =D1 _i × sinθ1 _i according to the obtained D1 _i and θ1 _i ; then select the minimum value L2= from K1 _i min{K1 _i }; calculate vehicle length L _l ＝L1-L2; Calculation method of vehicle width: first calculate the distance between the second laser radar and the vehicle on the ground according to the obtained D2 _(j,k) , D3 _(m,n) , θ2 _(j,k) , θ3 _(m,n) The projection distance W1 _(j,k) = D2 _(j,k) × sinθ2 _(j,k) , and the projection distance W2 _(m,n) on the ground between the third lidar and the vehicle = D3 _{(m, n)} × sinθ3 _(m,n) ; Then select the minimum value L4=min{W1 _(j,k) } and L5=min{W2 _(m,n) from W1 _(j,k) and W2 _(m,n) }; Calculate vehicle width L _w = L6-L4-L5; Calculation method of vehicle height: first calculate the vertical distance between the second laser radar and the top of the vehicle body according to the obtained D2 _(j,k) , D3 _(m,n) , θ2 _(j,k) , θ3 _(m,n) Projection distance H1 _(j,k) = -D2 _(j,k) × cosθ2 _(j,k) and the vertical projection distance between the third lidar and the top of the car body H2 _(m,n) = -D3 _{(m,n )} ×cosθ3 _(m,n) ; Then select the maximum value L8=max{H1 _{(j,k) }} and L9=max{H2 (m, _n) } from H1 _(j,k ) and H2 _(m,n) ; Calculate the second laser radar to measure the vehicle height L _h1 = L31+L8, calculate the third laser radar to measure the vehicle height L _h2 = L32+L9; according to the difference of the vehicle type, select one from L _h1 and L _h2 as the vehicle height, For large and medium-sized vehicles, the value calculated based on the parameters obtained from the higher distance measurement unit from the ground is the vehicle height value, while for small vehicles, the calculated value is based on the parameters obtained from the lower distance measurement unit from the ground The calculated value is the vehicle height value; Calculation method of the wheelbase: first calculate the projected distance K2 _{(x, y) on the ground between the first laser radar and the vehicle based on the obtained D4 (x, y)} and θ4 _{(x, y)} = D4 _{(x, y)} × sinθ4 _{(x, y)} ; select the minimum value L10 of the distance obtained in each frame of the first lidar when the wheel passes the wheelbase measurement control unit each time _y = min{K2 _{(x, y)} }; calculate the vehicle phase Distance L _wb(z) '=L10 _y -L10 _y+1 between two groups of adjacent wheels; calculate the wheelbase of the vehicle Where z is the number of axles of the vehicle, and the values are 1, 2, 3...y-1. 8. The vehicle profile and wheelbase automatic measurement algorithm according to claim 7, characterized in that, in the calculation process of vehicle width, the vehicle width is calculated after using the histogram to eliminate the vehicle rearview mirror data, and the histogram is used to eliminate the vehicle rearview The specific process of mirroring data is: form a histogram of all the data of W1 _(j,k) from low to high, and form a histogram of all data of W2 _(m,n) from low to high; delete |W1 when the comprehensive data processing unit calculates _(j,k) |, |W2 _(m,n) |, calculate the vehicle width after there is a step change in the data. 9. The vehicle profile and wheelbase automatic measurement algorithm according to claim 6, characterized in that, in the calculation process of the vehicle width, the vehicle width is calculated by using the morphological features of the vehicle to eliminate the vehicle rearview mirror data, and the vehicle morphological features are used to calculate the vehicle width. The specific process of eliminating vehicle rearview mirror data is as follows: Before calculating the vehicle width, input the vehicle type to the integrated data processing unit; _Calculate the projection _{distance W1 (j , k)} = D2 _(j,k) × sinθ2 _(j,k) , and the projected distance W2 _{(m,n) on the ground between the third lidar and the vehicle W2 (m,n)} = D3 _(m,n) × sinθ3 _{(m, n)} ; Calculate the average of all projected distances on the ground between the second lidar and the vehicle and the average of all projected distances on the ground between the third lidar and the vehicle The comprehensive data processing unit selects the data to be deleted that is less _than The data and W2 _(m,n) are less than The deleted data is different according to the type of vehicle. For large vehicles, the data deleted by the comprehensive data processing unit is the data before the vehicle tires pass the wheelbase measurement control unit for the first time. For small and medium-sized vehicles, the comprehensive data processing unit The deleted data is the data before the highest point of the vehicle starts to pass through the near-end arch.