CN102692297B - Braking process-based dynamic automobile gravity position detector and method - Google Patents

Abstract

The invention relates to braking process-based dynamic automobile gravity position detector and a method. The device consists of an axle weight, a braking force detector, an axle base measuring device, a wheel base measuring device and a data collection processing system; dynamic gravity detection algorithm is obtained by derivation on the basis of braking process, the device is applied to collect axle weight and braking force signals, axle base signals and wheel base signals, thus being capable of calculating the position of the automotive gravity. Based on the automotive gravity position calculation method, sideslip and rolling-over of vehicles can be analyzed to calculate limiting values of sideslip and rolling-over of vehicles under different road conditions and give out early-warning information to avoid occurrence of traffic accidents. The invention can be widely applied in safety driving control process of various vehicles.

Description

Translated fromChinese

基于制动过程的汽车重心位置动态检测装置及方法Device and method for dynamic detection of vehicle center of gravity position based on braking process

技术领域technical field

本发明属于基于制动过程的汽车重心位置动态检测装置及方法，是通过轴重、制动力、轴距及轮距的测量，实现汽车重心位置的快速、有效检测的方法。The invention belongs to a device and method for dynamically detecting the position of the center of gravity of an automobile based on a braking process, and is a method for quickly and effectively detecting the position of the center of gravity of an automobile through the measurement of axle load, braking force, wheelbase and wheel base.

背景技术Background technique

在所有的交通事故中，汽车侧翻事故的危害程度仅次于汽车碰撞事故。车辆侧翻除了驾驶员操作的失误原因，车辆的许多参数的偏差也是事关重要的因素。而汽车重心位置又是这些参数中最为重要且不易测量的参数之一。因此对汽车重心位置的动态检测具有重要意义。汽车的重心位置通常用汽车重心水平位置和汽车重心高度来表示。Among all traffic accidents, the degree of harm of automobile rollover accidents is second only to automobile collision accidents. In addition to the driver's error in the vehicle rollover, the deviation of many parameters of the vehicle is also an important factor. The center of gravity position of the vehicle is one of the most important and difficult to measure parameters among these parameters. Therefore, the dynamic detection of the position of the center of gravity of the vehicle is of great significance. The position of the center of gravity of the car is usually expressed by the horizontal position of the center of gravity of the car and the height of the center of gravity of the car.

目前，国内外测定汽车重心位置的方法主要有摇摆法、悬挂法、零位法、平台支撑反力法、重量反应法。但是，以上这些都是静态的测量方法，测量费时费力，且与动态时车辆的重心高度等参数的实际位置有一定的偏差。因此研究一种测量精度高、成本低、快速的汽车重心位置动态检测方法，具有重要的实用价值。At present, the methods for determining the center of gravity of automobiles at home and abroad mainly include swing method, suspension method, zero position method, platform support reaction force method, and weight response method. However, all of the above are static measurement methods, which are time-consuming and labor-intensive, and have certain deviations from the actual positions of parameters such as the height of the center of gravity of the vehicle during dynamic conditions. Therefore, it is of great practical value to study a dynamic detection method for the position of the center of gravity of the vehicle with high measurement accuracy, low cost and fast.

发明内容Contents of the invention

本发明主要目的在于提供一种能够在制动过程中准确、迅速检测重心位置的基于制动过程的汽车重心位置动态检测装置及方法。The main purpose of the present invention is to provide a dynamic detection device and method for the position of the center of gravity of an automobile based on the braking process, which can accurately and rapidly detect the position of the center of gravity during the braking process.

本发明的上述目的通过以下技术方案实现，结合附图说明如下：Above-mentioned purpose of the present invention is realized by following technical scheme, is described as follows in conjunction with accompanying drawing:

一种基于制动过程的汽车重心位置动态检测装置，包括轴重、制动力检测装置、轴距测量装置、轮距测量装置和数据采集处理系统，所述轴重、制动力检测装置包括制动台板16、挡轮13、3号对射式光电开关14、制动力传感器15和轴重传感器12，所述制动台板16由下面的背板和框架支撑，所述制动力传感器15装在每块制动台板16前端的左右侧，所述轴重传感器12装在制动台板16的下方，所述挡轮13装在制动台板16的两侧，所述3号对射式光电开关14装在在制动台板16中部的两侧；A dynamic detection device for the position of the center of gravity of an automobile based on the braking process, comprising an axle load and braking force detection device, a wheelbase measurement device, a wheelbase measurement device and a data acquisition and processing system, the axle load and braking force detection device includes a brake Platen 16, retaining wheel 13, No. 3 through-beam photoelectric switch 14, braking force sensor 15 and axle load sensor 12, described braking platen 16 is supported by the backboard and frame below, and described braking force sensor 15 is installed On the left and right sides of the front end of each braking platen 16, the axle load sensor 12 is installed under the braking platen 16, the retaining wheel 13 is installed on both sides of the braking platen 16, and the No. 3 pair Radiation photoelectric switch 14 is installed on both sides of the middle part of braking platen 16;

所述轴距测量装置包括左右侧导轨21、11、装在导轨上的移动式小车30、装在移动式小车顶部的激光反光板35、装在移动式小车中部的漫反射式光电开关34以及分别装在左、右侧导轨前面的激光测距仪；Described wheelbase measuring device comprises left and right side guide rails 21,11, the movable type trolley 30 that is contained on the guide rail, the laser reflector 35 that is contained in the movable type trolley top, the diffuse reflection type photoelectric switch 34 that is contained in the movable type trolley middle part and Laser range finders installed in front of the left and right rails respectively;

所述轮距测量装置包括装在平板制动台16前端的左右两侧的1、2号对射式光电开关7、8、装在平板制动台16前端左右两侧和中间的激光测距仪；The wheelbase measurement device includes No. 1 and No. 2 through-beam photoelectric switches 7, 8 installed on the left and right sides of the front end of the flat brake table 16, and laser distance measuring devices installed on the left and right sides and the middle of the front end of the flat brake table 16. instrument;

所述制动台板16为4快，每两块的长宽之和按小型车的轴距和车宽确定，制动台板16板面的附着系数在0.1以上；所述制动力传感器15与制动台板16间应保留0.2mm-0.3mm左右的间隙；每块制动台板16的下方装有6个轴重传感器12，最大称重5000kg。Described braking platen 16 is 4 fast, and the sum of the length and width of every two pieces is determined by the wheelbase and the vehicle width of small car, and the adhesion coefficient of braking platen 16 plate surface is more than 0.1; Described braking force sensor 15 A gap of about 0.2mm-0.3mm should be reserved between the braking platen 16; 6 axle load sensors 12 are installed below each braking platen 16, and the maximum weighing capacity is 5000kg.

所述左侧导轨21和右侧导轨11均平行于行车中心线；所述漫反射式光电开关34应与地面平行，与行车中心线保持垂直，且高度不能超过轮毂的最低点，漫反射式光电开关34的最大有效距离应在1000mm～1200mm之间；The left guide rail 21 and the right guide rail 11 are all parallel to the center line of the vehicle; the diffuse reflection photoelectric switch 34 should be parallel to the ground, perpendicular to the center line of the vehicle, and the height cannot exceed the lowest point of the wheel hub. The maximum effective distance of the photoelectric switch 34 should be between 1000mm and 1200mm;

所述激光反光板35表面垂直于地面且垂直于行车中心线，在激光反光板中心31处刻画有十字形的准心，用于激光的标定和检查；在左侧导轨21的前方安装1号激光测距仪1，在右侧导轨11的前端安装2号激光测距仪6，1号激光测距仪1和2号激光测距仪6发射的光线均应平行于行车中心线和地面，同时要保证在移动式小车30的整个运动行程中，二者的照射点一直位于激光反光板35上的准心处。The surface of the laser reflector 35 is perpendicular to the ground and the center line of the vehicle, and a cross-shaped centerline is drawn at the center 31 of the laser reflector for laser calibration and inspection; No. 1 is installed in front of the left guide rail 21 Laser range finder 1, No. 2 laser range finder 6 is installed at the front end of right side guide rail 11, the light emitted by No. 1 laser range finder 1 and No. 2 laser range finder 6 should be parallel to the driving center line and the ground, Simultaneously, it must be ensured that the irradiation points of the two are always located at the quasicenter on the laser reflector 35 during the entire movement stroke of the mobile trolley 30 .

所述1、2号对射式光电开关7、8的有效距离应在3500mm-4000mm之间；所述激光测距仪装在车轮定位线(41)上，3、6号激光测距仪2、5分别安装在左右两侧，4、5号激光测距仪3、4安装在中间，四个激光测距仪发射的光线均应垂直于行车中心线且平行于地面，4、5号激光测距仪3、4均应尽量靠近行车中心线，以防车辆开偏测量不到。The effective distance of No. 1 and No. 2 through-beam photoelectric switches 7 and 8 should be between 3500mm-4000mm; , 5 are installed on the left and right sides respectively, and No. Rangefinders 3 and 4 should be as close as possible to the center line of the vehicle to prevent the vehicle from being deviated from the measurement.

一种用于上述的基于制动过程的汽车重心位置动态检测装置进行汽车重心位置动态检测方法，包括以下具体步骤：A method for dynamically detecting the position of the center of gravity of the vehicle based on the above-mentioned braking process-based dynamic detection device for the position of the center of gravity of the vehicle, comprising the following specific steps:

1数据采集处理系统中的设备调零，采集轴重、制动力信号1 The equipment in the data acquisition and processing system is zeroed, and the axle load and braking force signals are collected

当车辆进入检测场地后，点阵显示屏29提示车辆以每小时5-10公里的初速度行驶上检测装置，当车辆前轮经过3号对射式光电开关14时，引起3号对射式光电开关14的电压发生变化，此信号被工控机28接收，记录轴重、制动力传感器测量的车辆动态的轴重、制动力，并通过点阵显示屏29显示刹车；当车辆完全静止后，点阵显示屏29将显示车辆左右前轮载荷、左右后轮载荷和汽车总重，工控机28的显示器界面出现轴重和制动力信号随时间变化关系的曲线。After the vehicle enters the detection site, the dot matrix display screen 29 prompts the vehicle to run on the detection device at an initial speed of 5-10 kilometers per hour. The voltage of the photoelectric switch 14 changes, and this signal is received by the industrial computer 28, which records the axle load and the dynamic axle load and braking force of the vehicle measured by the braking force sensor, and displays the brakes through the dot matrix display screen 29; when the vehicle is completely stationary, The dot matrix display screen 29 will display the left and right front wheel loads, the left and right rear wheel loads and the total vehicle weight of the vehicle, and the display interface of the industrial computer 28 will show the curve of the axle load and the braking force signal as a function of time.

2采集轴距信号2 Acquisition of wheelbase signals

当车辆完全静止后，移动式小车30由导轨前端向导轨后端移动，当移动式小车30上的漫反射式光电开关34感应到前、后轮胎的前、后沿时，其电压均开始变化，工控机28根据电压变化信号，对激光测距仪发出指令，测量在这四个时刻的漫反射式光电开关34到激光测距仪的距离；当移动式小车30接触到行程开关后，自动回到初始位置。When the vehicle is completely stationary, the mobile trolley 30 moves from the front end of the guide rail to the rear end of the rail. When the diffuse reflection photoelectric switch 34 on the mobile trolley 30 senses the front and rear edges of the front and rear tires, its voltage starts to change. , the industrial computer 28 sends instructions to the laser range finder according to the voltage change signal, and measures the distance from the diffuse reflection photoelectric switch 34 to the laser range finder at these four moments; Return to the initial position.

3)采集轮距信号3) Collect wheel base signal

车辆向前缓慢移动，当车辆前轮完全挡住1号对射式光电开关7和2号对射式光电开关8时，3号激光测距仪2、4号激光测距仪3、5号激光测距仪4和6号激光测距仪5同时测量，得到相应端面的距离值，后轮轮距测量方法与前轮相同。The vehicle moves forward slowly. When the front wheels of the vehicle completely block the No. 1 through-beam photoelectric switch 7 and No. 2 through-beam photoelectric switch 8, the No. 3 laser range finder 2, No. 4 laser range finder 3, and No. 5 laser The range finder 4 and the No. 6 laser range finder 5 measure at the same time to obtain the distance value of the corresponding end face, and the rear wheel track measurement method is the same as that of the front wheel.

4通过重心位置动态检测算法计算出汽车重心位置4 Calculate the center of gravity position of the vehicle through the dynamic detection algorithm of the center of gravity position

重心至前轴中心线的距离：Distance from the center of gravity to the centerline of the front axle:

重心至后轴中心线的距离：Distance from the center of gravity to the centerline of the rear axle:

重心至两左轮中心连线的距离：The distance from the center of gravity to the line connecting the centers of the two left wheels:

重心至两右轮中心连线的距离：The distance from the center of gravity to the line connecting the centers of the two right wheels:

重心高度：Center of gravity height:

其中：设φ为车身绕重心的角位移、K_f为前轴弹簧刚度、K_r为后轴弹簧刚度。设G为汽车总重、G₁为后轴载荷、G₂为两右轮载荷、G₃为前轴载荷、B为汽车轮距、为平板制动台附着系数，L为汽车轴距，G′为前轴载荷最大时刻对应的汽车总重，F_Z1、F_Z2分别为前轴载荷最大时刻对应的地面对前、后轮的法向反作用力。in: Let φ be the angular displacement of the body around the center of gravity, K_f be the spring stiffness of the front axle, and K_r be the spring stiffness of the rear axle. Let G be the total weight of the vehicle,_G1 be the load on the rear axle,_G2 be the load on the two right wheels,_G3 be the load on the front axle, B be the wheelbase of the vehicle, is the adhesion coefficient of the plate brake table, L is the wheelbase of the vehicle, G′ is the total weight of the vehicle corresponding to the moment of the maximum front axle load, F_Z1 and F_Z2 are the distances of the ground to the front and rear wheels corresponding to the moment of the maximum front axle load Normal reaction force.

本发明的技术效果：Technical effect of the present invention:

1、基于静态的重心位置测量方法，不仅测量费时费力，而且与动态时车辆的重心高度等参数的实际位置有一定的偏差，提出了在制动过程中动态检测汽车重心位置的方法。1. Based on the static center of gravity position measurement method, not only the measurement is time-consuming and laborious, but also has a certain deviation from the actual position of the vehicle's center of gravity height and other parameters in dynamic conditions. A method for dynamically detecting the position of the vehicle's center of gravity during braking is proposed.

2、本发明通过轴重、制动力检测装置、轴距测量装置、轮距测量装置和数据采集处理系统对轴重、制动力信号，轴距信号和轮距信号进行采集，并通过重心位置动态检测算法，实现了汽车重心位置快速、准确的测量。2. The present invention collects the axle load, braking force signal, wheelbase signal and wheelbase signal through the axle load, braking force detection device, wheelbase measuring device, wheel base measuring device and data acquisition and processing system, and dynamically detects the signal through the position of the center of gravity. The detection algorithm realizes the fast and accurate measurement of the position of the center of gravity of the vehicle.

3、本发明可以基于计算出的汽车重心位置，对车辆侧滑、侧翻进行分析，计算出在不同路况下车辆侧滑、侧翻的极限值，并发出预警信息，避免交通事故的发生。本发明可广泛应用于各种车辆的行驶安全控制过程中。3. The present invention can analyze the sideslip and rollover of the vehicle based on the calculated position of the center of gravity of the vehicle, calculate the limit values of the vehicle's sideslip and rollover under different road conditions, and issue early warning information to avoid traffic accidents. The invention can be widely used in the running safety control process of various vehicles.

4、本发明方法操作简单，易于维护，可以方便地应用于汽车检测线上，并可有效地实施检测。4. The method of the present invention is simple to operate and easy to maintain, and can be conveniently applied to automobile inspection lines and can effectively implement inspection.

附图说明Description of drawings

图1基于制动过程的汽车重心位置动态检测装置结构图。Figure 1 is a structural diagram of a dynamic detection device for the center of gravity of a vehicle based on the braking process.

图2轴距测量装置中移动式小车及导轨示意图。其中，Figure 2 Schematic diagram of the mobile trolley and guide rail in the wheelbase measuring device. in,

图2(a)是俯视图；图2(b)是主视图；图2(c)是左视图。Figure 2(a) is a top view; Figure 2(b) is a front view; Figure 2(c) is a left view.

图3轴距测量原理图。Figure 3 schematic diagram of wheelbase measurement.

图4前轮轮距测量装置图。其中，图4(a)是俯视图；图4(b)是主视图。Figure 4 is a diagram of the front wheel track measuring device. Among them, Fig. 4(a) is a top view; Fig. 4(b) is a front view.

图5后轮轮距测量装置图。其中，图5(a)是俯视图；图5(b)是主视图。Figure 5 is a diagram of the rear wheel track measuring device. Among them, Fig. 5(a) is a top view; Fig. 5(b) is a front view.

图6重心水平位置测量原理图。Fig. 6 Schematic diagram of measuring the horizontal position of the center of gravity.

图7数据采集处理系统原理图。Figure 7 is a schematic diagram of the data acquisition and processing system.

图8制动过程中汽车受力分析图。Figure 8 is the force analysis diagram of the vehicle during the braking process.

图9汽车重心位置检测流程图。Figure 9 is a flow chart of vehicle center of gravity position detection.

图中：1.1号激光测距仪 2.3号激光测距仪 3.4号激光测距仪 4.5号激光测距仪 5.6号激光测距仪 6.2号激光测距仪 7.1号对射式光电开关 8.2号对射式光电开关 9.右侧移动式小车上的激光反光板 10.右侧移动式小车上的漫反射式光电开关 11.右侧导轨12.轴重传感器 13.挡轮 14.3号对射式光电开关 15.制动力传感器 16.制动台板 17.右侧导轨上的行程开关 18.左侧移动式小车上的激光反光板 19.左侧移动式小车上的漫反射式光电开关 20.左侧导轨上的行程开关 21.左侧导轨 22.激光光线 23.对射式光电开关24.左前轮 25.右前轮 26.左后轮 27.右后轮 28.工控机 29.点阵显示屏 30.移动式小车31.激光反光板中心 32.车轮 33.导轨 34.漫反射式光电开关 35.激光反光板 36.开关量接线板 37.模拟量接线板 38.模拟量采集卡 39.开关量采集卡 40.串口扩展卡 41.车轮定位线In the figure: No. 1.1 laser range finder No. 2.3 laser range finder No. 3.4 laser range finder No. 4.5 laser range finder No. 5.6 laser range finder No. 6.2 laser range finder No. 7.1 through-beam photoelectric switch 8.2 through-beam Type photoelectric switch 9. Laser reflector on the right mobile trolley 10. Diffuse reflection photoelectric switch on the right mobile trolley 11. Right guide rail 12. Axle load sensor 13. Stop wheel 14. No. 3 through-beam photoelectric switch 15. Braking force sensor 16. Braking platen 17. Travel switch on the right guide rail 18. Laser reflector on the left mobile trolley 19. Diffuse reflection photoelectric switch on the left mobile trolley 20. Left side Travel switch on guide rail 21. Left guide rail 22. Laser light 23. Opposed photoelectric switch 24. Left front wheel 25. Right front wheel 26. Left rear wheel 27. Right rear wheel 28. Industrial computer 29. Dot matrix display Screen 30. Mobile trolley 31. Laser reflector center 32. Wheel 33. Guide rail 34. Diffuse reflection photoelectric switch 35. Laser reflector 36. Switching quantity wiring board 37. Analog quantity wiring board 38. Analog quantity acquisition card 39. Switch value acquisition card 40. Serial expansion card 41. Wheel alignment line

具体实施方式Detailed ways

下面结合附图所示实施例进一步详细说明本发明的具体方法及装置实施方式。The specific methods and device implementations of the present invention will be further described in detail below in conjunction with the embodiments shown in the accompanying drawings.

为便于实验，本文以小型车(3.5吨以下)为例，进行相关的分析和实验。In order to facilitate the experiment, this paper takes a small car (less than 3.5 tons) as an example to carry out relevant analysis and experiments.

基于制动过程的汽车重心位置动态检测装置，它包括轴重、制动力检测装置、轴距测量装置、轮距测量装置及数据采集处理系统：A dynamic detection device for the position of the center of gravity of an automobile based on the braking process, which includes an axle load, a braking force detection device, a wheelbase measurement device, a wheelbase measurement device and a data acquisition and processing system:

1)参阅图1，所述的轴重、制动力检测装置包括制动台板(16)、挡轮(13)、3号对射式光电开关(14)、制动力传感器(15)及轴重传感器(12)。小型车的车宽一般不会超过2.1m(特种车除外)，但考虑到车辆行驶的偏差，两块制动台板(16)宽度和控制在2700mm左右。而小型车的轴距一般都集中在2340mm(奇瑞QQ)-3150mm(奔驰E级加长)，加上刹车距离(在速度5-10km/h的情况下刹车，刹车距离一般不会超过1-1.5m)，设计的制动台板(16)的长度应达到4.7m，本装置设计两块制动台板(16)的长度为2400mm，中间还有360mm的距离，使实际长度接近6m。制动台板(16)板面采用特殊工艺的粘结复合材料层，有效提高板面的附着系数(应达到0.1以上)，这样就能增大制动效能，降低因轮胎表面有水或粘有雪等因素对制动力的影响。制动台板(16)应牢固可靠，下面有背板和支撑的框架。制动台板(16)前侧应设有制动力传感器(15)(左右各一个)，测量最大值为4000N。制动力传感器(15)一面与制动台板(16)连接，一面与框架连接，制动力传感器(15)与制动台板(16)间应保留0.2mm-0.3mm左右的间隙。在制动台板(16)的下方设有轴重传感器(12)，考虑到制动台板(16)的长度，本装置在每块制动台板(16)的下方装有6个轴重传感器(12)，最大称重5000kg。1) Referring to Fig. 1, the described axle load and braking force detection device includes a braking platen (16), a retaining wheel (13), No. 3 through-beam photoelectric switch (14), a braking force sensor (15) and a shaft Heavy sensor (12). The car width of compact car generally can not exceed 2.1m (except special vehicle), but considering the deviation of vehicle running, two brake platen (16) width sums are controlled at about 2700mm. The wheelbase of small cars is generally concentrated in 2340mm (Chery QQ)-3150mm (Mercedes-Benz E-class extension), plus the braking distance (braking at a speed of 5-10km/h, the braking distance will generally not exceed 1-1.5 m), the length of the brake platen (16) of design should reach 4.7m, and the length of two brake platens (16) of this device design is 2400mm, also has the distance of 360mm in the middle, makes actual length close to 6m. The surface of the brake plate (16) adopts a bonded composite material layer with a special process, which effectively improves the adhesion coefficient of the surface (should reach more than 0.1), so that the braking performance can be increased, and the tire surface can be reduced due to water or stickiness. There are factors such as snow that affect the braking force. Braking platen (16) should be firm and reliable, and the frame of backboard and support is arranged below. The front side of the braking platen (16) should be provided with a braking force sensor (15) (one each on the left and right), and the maximum measurement value is 4000N. One side of the braking force sensor (15) is connected with the braking platen (16), and the other side is connected with the frame. A gap of about 0.2mm-0.3mm should be reserved between the braking force sensor (15) and the braking platen (16). An axle load sensor (12) is arranged under the braking platen (16). Considering the length of the braking platen (16), the device is equipped with 6 shafts under each braking platen (16). Load sensor (12), maximum weighing 5000kg.

2)参阅图1、图2，所述的轴距测量装置是在平板制动台的两侧分别安装左侧导轨(21)和右侧导轨(11)，两导轨均平行于行车中心线，在导轨上安装移动式小车(30)，在移动式小车(30)的中间加装一个漫反射式光电开关(34)，此漫反射式光电开关(34)，应与地面平行，与行车中心线保持垂直，且高度不能超过轮毂的最低点，考虑到轮胎的宽度都在150mm以上，所以漫反射式光电开关(34)的最大有效距离应在1200mm以内且不应小于1000mm。在移动式小车(30)的上面安装一块激光反光板(35)，此激光反光板(35)的表面不仅要垂直于地面而且要垂直于行车中心线，并在激光反光板中心(31)处刻画有十字形的准心，为激光的标定和检查做准备。在左侧导轨(21)的前端安装1号激光测距仪(1)，在右侧导轨(11)的前端安装2号激光测距仪(6)。1号激光测距仪(1)和2号激光测距仪(6)，二者所发射的光线均应平行于行车中心线和地面，同时还要保证在移动式小车(30)的整个运动行程中，二者的照射点一直位于激光反光板(35)上的准心处。2) Referring to Fig. 1 and Fig. 2, the described wheelbase measuring device is to respectively install a left side guide rail (21) and a right side guide rail (11) on both sides of the flat brake table, and the two guide rails are all parallel to the driving center line, Install the mobile trolley (30) on the guide rail, and install a diffuse reflection photoelectric switch (34) in the middle of the mobile trolley (30). This diffuse reflection photoelectric switch (34) should be parallel to the ground, The line remains vertical, and the height cannot exceed the lowest point of the wheel hub. Considering that the width of the tire is more than 150mm, the maximum effective distance of the diffuse reflection photoelectric switch (34) should be within 1200mm and should not be less than 1000mm. A laser reflector (35) is installed above the mobile dolly (30), the surface of this laser reflector (35) will not only be perpendicular to the ground but also perpendicular to the driving center line, and at the center of the laser reflector (31) A cross-shaped crosshair is engraved to prepare for laser calibration and inspection. No. 1 laser range finder (1) is installed at the front end of left side guide rail (21), and No. 2 laser range finder (6) is installed at the front end of right side guide rail (11). No. 1 laser range finder (1) and No. 2 laser range finder (6), the light emitted by both should be parallel to the driving center line and the ground, and also ensure that the entire movement of the mobile dolly (30) In the stroke, the irradiation points of the two are positioned at the quasicenter on the laser reflector (35) always.

3)参阅图1、图4和图5，所述的前、后轮轮距测量装置是在平板制动台前端的左右两侧安装1、2号对射式光电开关(7)、(8)，其有效距离应在3500mm-4000mm之间。在车轮定位线上，左侧安装一个3号激光测距仪(2)，中间偏左侧安装一个4号激光测距仪(3)，中间偏右侧安装一个5号激光测距仪(4)，右侧安装一个6号激光测距仪(5)。由于3、4、5、6号激光测距仪每两个的距离都没有超过1500mm，所以该激光测距仪的有效距离选择小一点就可以，四个激光测距仪发射的光线均应垂直于行车中心线且平行于地面，4号激光测距仪(3)和5号激光测距仪(4)均应尽量的靠近行车中心线，以防车辆开偏测量不到。3) Referring to Fig. 1, Fig. 4 and Fig. 5, the described front and rear wheel track measurement device is to install No. 1 and No. 2 through-beam photoelectric switches (7), (8) on the left and right sides of the front end of the flat plate braking platform. ), the effective distance should be between 3500mm-4000mm. On the wheel alignment line, a No. 3 laser range finder (2) is installed on the left side, a No. 4 laser range finder (3) is installed on the left side of the middle, and a No. 5 laser range finder (4) is installed on the right side of the middle ), a No. 6 laser range finder (5) is installed on the right side. Since the distance between each of No. 3, 4, 5, and 6 laser range finders does not exceed 1500mm, the effective distance of the laser range finder can be selected to be a little smaller, and the light emitted by the four laser range finders should be vertical On the center line of the vehicle and parallel to the ground, the No. 4 laser range finder (3) and the No. 5 laser range finder (4) should be as close as possible to the center line of the vehicle to prevent the vehicle from being deviated from the measurement.

4)参阅图7，所述的数据采集处理系统包括工控机(28)、开关量接线板(36)、点阵显示屏(29)、开关量采集卡(39)、模拟量采集卡(38)、模拟量接线板(37)和串口扩展卡(40)。市面上常用的点阵显示屏(29)有16点阵显示屏和24点阵显示屏。16点阵显示屏上下分屏各显示六个字，24点阵显示屏上下分屏各显示八个字，为了达到更好的显示效果，本发明选用了24点阵显示屏。同时，点阵显示屏的通信口设计成485串口模式，这样有效的避免了信号的干扰。为达到较高的使用效能，选用了功能较多的工控机(28)，其参数为：CPU酷睿双核2.4G、内存2G、硬盘250G、24XDVD光驱，该机本身带有1个VGA口、1个网线口、1个键盘鼠标接线口、1个打印机口、2个232接口、1个485接口、2个USB接口，除本身带的接口(占用3个ISA插槽)，还有5个ISA插槽和4个PCI插槽备用。开关量接线板(36)选用北京康拓工业电脑公司的IPC5375I/O板。模拟量接线板(37)选用北京康拓工业电脑公司的IPC5488板。串口扩展卡(40)选用MOXA 168H型。系统中的制动力和轴重传感器均为模拟量信号，输出在0-10mV左右，根据模拟量采集卡(38)的信号输入要求，需安装信号处理模块，本发明选用北京阿尔泰科技发展有限公司的A11B11型信号处理模块，该模块供电电压+24V，输入电压0-15mV，输出电压0-5V。电源选用深圳生产的长城电源。此数据采集处理系统实时采集轴重、制动力信号，各个对射式光电开关、漫反射式光电开关、行程开关和激光测距仪的信号，通过点阵显示屏(29)显示相关数据及命令，并通过其内部设置的算法进行相应运算。4) Referring to Fig. 7, described data acquisition and processing system comprises industrial computer (28), switching quantity wiring board (36), dot matrix display screen (29), switching quantity acquisition card (39), analog quantity acquisition card (38) ), analog wiring board (37) and serial port expansion card (40). Dot matrix display (29) commonly used on the market has 16 dot matrix display and 24 dot matrix display. The upper and lower sub-screens of the 16-dot matrix display screen each display six characters, and the upper and lower sub-screens of the 24-dot matrix display screen each display eight characters. In order to achieve a better display effect, the present invention selects a 24-dot matrix display screen. At the same time, the communication port of the dot matrix display is designed as a 485 serial port mode, which effectively avoids signal interference. In order to achieve higher use efficiency, an industrial computer (28) with more functions is selected. Its parameters are: CPU Core Duo 2.4G, memory 2G, hard disk 250G, 24XDVD drive. This machine itself has 1 VGA port, 1 1 network cable port, 1 keyboard and mouse connection port, 1 printer port, 2 232 ports, 1 485 port, 2 USB ports, in addition to the port itself (occupies 3 ISA slots), there are 5 ISA ports slot and 4 PCI slots for spare. The switch quantity wiring board (36) selects the IPC5375I/O board of Beijing Kangtuo Industrial Computer Company for use. The analog quantity wiring board (37) selects the IPC5488 board of Beijing Kangtuo Industrial Computer Company. Serial port expansion card (40) selects MOXA 168H type for use. The braking force in the system and the axle load sensor are all analog signals, and the output is about 0-10mV. According to the signal input requirements of the analog acquisition card (38), a signal processing module needs to be installed. The present invention selects Beijing Altai Science and Technology Development Co., Ltd. The A11B11 signal processing module has a power supply voltage of +24V, an input voltage of 0-15mV, and an output voltage of 0-5V. The power supply is the Great Wall power supply produced in Shenzhen. This data acquisition and processing system collects axle load and braking force signals in real time, the signals of each through-beam photoelectric switch, diffuse reflection photoelectric switch, travel switch and laser rangefinder, and displays relevant data and commands through the dot matrix display (29) , and perform corresponding operations through its internally set algorithm.

本发明方法包括以下步骤：The inventive method comprises the following steps:

1)数据采集处理系统中的设备调零，采集轴重、制动力信号1) The equipment in the data acquisition and processing system is zeroed, and the axle load and braking force signals are collected

当车辆进入检测场地后，点阵显示屏(29)提示车辆以每小时5-10公里的初速度行驶上检测装置，当车辆前轮经过3号对射式光电开关(14)时，3号对射式光电开关(14)的电压将发生变化，工控机(28)在接收到此电压变化信号后，将记录轴重、制动力传感器测量的车辆动态的轴重、制动力，并通过点阵显示屏(29)显示刹车。当车辆完全静止后，点阵显示屏(29)将显示车辆左前轮载荷、右前轮载荷、左后轮载荷、右后轮载荷和汽车总重，工控机(28)的显示器界面出现轴重和制动力信号随时间变化关系的曲线。After the vehicle enters the detection site, the dot matrix display screen (29) prompts the vehicle to run on the detection device at an initial speed of 5-10 kilometers per hour. The voltage of the through-beam photoelectric switch (14) will change, and the industrial computer (28) will record the dynamic axle load and braking force of the vehicle measured by the axle load and the braking force sensor after receiving the voltage change signal, and pass through the point Array display screen (29) shows braking. After the vehicle is completely still, the dot matrix display screen (29) will display the vehicle left front wheel load, right front wheel load, left rear wheel load, right rear wheel load and vehicle gross weight, and the display interface of the industrial computer (28) appears the axis The curve of the relationship between weight and braking force signal with time.

2)采集轴距信号2) Collect wheelbase signal

车辆完全静止后，开始测量轴距。由于左右侧轴距的测量原理相同，所以在图3中，仅标明了右侧轴距的测量原理。参阅图3，可知右侧轴距的测量原理为：当车辆完全静止后，车辆右侧的移动式小车由右侧导轨(11)的前端向右侧导轨(11)的后端移动，当右侧移动式小车上的漫反射式光电开关(10)感应到前轮胎的前沿时，此漫反射式光电开关的电压开始变化，工控机(28)根据此电压变化信号，对2号激光测距仪(6)发出指令，测量当前右侧移动式小车上的漫反射式光电开关(10)到2号激光测距仪(6)的距离；移动式小车继续移动，当右侧移动小车上的漫反射式光电开关(10)感应到前轮胎的后沿时，此漫反射式光电开关的电压开始变化，工控机(28)根据此电压变化信号，对2号激光测距仪(6)发出指令，测量当前右侧移动式小车上的漫反射式光电开关(10)到2号激光测距仪(6)的距离；移动式小车继续移动，当右侧移动小车上的漫反射式光电开关(10)感应到后轮胎的前沿时，此漫反射式光电开关的电压开始变化，工控机(28)根据此电压变化信号，对2号激光测距仪(6)发出指令，测量当前右侧移动式小车上的漫反射式光电开关(10)到2号激光测距仪(6)的距离；移动式小车继续移动，当右侧移动式小车上的漫反射式光电开关(10)感应到后轮胎的后沿时，此漫反射式光电开关的电压开始变化，工控机(28)根据此电压变化信号，对2号激光测距仪(6)发出指令，测量当前右侧移动式小车上的漫反射式光电开关(10)到2号激光测距仪(6)的距离；移动式小车继续移动，当其接触到行程开关后，自动回到初始位置。After the vehicle is completely stationary, start measuring the wheelbase. Since the measurement principles of the left and right wheelbases are the same, only the measurement principle of the right wheelbase is indicated in Fig. 3 . Referring to Fig. 3, it can be seen that the measurement principle of the right side wheelbase is: when the vehicle is completely stationary, the mobile trolley on the right side of the vehicle moves from the front end of the right guide rail (11) to the rear end of the right guide rail (11). When the diffuse reflection photoelectric switch (10) on the side mobile dolly senses the leading edge of the front tire, the voltage of the diffuse reflection photoelectric switch begins to change, and the industrial computer (28) measures the distance of the No. 2 laser according to the voltage change signal. The meter (6) sends out an instruction to measure the distance from the diffuse reflection photoelectric switch (10) on the current right mobile dolly to the No. 2 laser range finder (6); the mobile dolly continues to move, and when the right mobile dolly When the diffuse reflection photoelectric switch (10) senses the trailing edge of the front tire, the voltage of the diffuse reflection photoelectric switch begins to change, and the industrial computer (28) sends a signal to No. 2 laser range finder (6) according to the voltage change signal. Command, measure the distance from the diffuse reflection photoelectric switch (10) on the current right mobile trolley to the No. 2 laser range finder (6); the mobile trolley continues to move, when the diffuse reflection photoelectric switch on the right mobile trolley (10) When the leading edge of the rear tire is sensed, the voltage of the diffuse reflection photoelectric switch begins to change, and the industrial computer (28) sends instructions to the No. 2 laser range finder (6) according to the voltage change signal to measure the current right side. The distance from the diffuse reflection photoelectric switch (10) on the mobile dolly to No. 2 laser range finder (6); the mobile dolly continues to move, and when the diffuse reflection photoelectric switch (10) on the right mobile dolly senses When the rear tire is on the trailing edge, the voltage of this diffuse reflection photoelectric switch begins to change, and the industrial computer (28) sends an instruction to No. 2 laser rangefinder (6) according to the voltage change signal, and measures the distance on the current right mobile dolly. The distance from the diffuse reflection photoelectric switch (10) to the No. 2 laser rangefinder (6); the mobile dolly continues to move, and when it touches the travel switch, it returns to the initial position automatically.

一般情况下，漫反射式光电开关(10)有一定的扩散角度(设此角度为θ)，所以其在感应车轮(32)的时候有一个提前量和一个滞后量。另外，由于车辆停驶方向不一定与行车中心线完全的平行，因此漫反射式光电开关靠近车轮侧到轮胎感应面的垂直距离有一定差异。设图3中自右向左，漫反射式光电开关靠近车轮侧到轮胎感应面的垂直距离依次为c₁、c₂、c₃、c₄，则测量时右前轮(25)前感应点的提前量为c₁×tanθ，右前轮(25)后感应点的滞后量为c₂×tanθ，右后轮(27)前感应点的提前量为c₃×tanθ，右后轮(27)后感应点的滞后量为c₄×tanθ。但考虑到大多数车辆停驶时的偏移角度不大且θ很小，所以在此可认为c₁×tanθ＝c₂×tanθ、c₃×tanθ＝c₄×tanθ。设右侧移动式小车在图3所示从右至左的四个位置时，2号激光测距仪(6)到右侧移动式小车上的漫反射式光电开关(10)的距离分别为L_f1、L_f2、L_r1、L_r2，2号激光测距仪(6)到右前轮(25)中心所在的与其行驶方向垂直的平面的距离为L_f，到右后轮(27)中心所在的与其行驶方向垂直的平面的距离L_r，则Generally speaking, the diffuse reflection photoelectric switch (10) has a certain diffusion angle (set this angle as θ), so it has an advance amount and a lag amount when sensing the wheel (32). In addition, since the vehicle's parking direction is not necessarily completely parallel to the driving centerline, there is a certain difference in the vertical distance from the diffuse reflection photoelectric switch near the wheel side to the tire sensing surface. Assuming that from right to left in Figure 3, the vertical distances from the side of the diffuse reflection photoelectric switch near the wheel to the sensing surface of the tire are c₁ , c₂ , c₃ , c₄ in sequence, then the front sensing point of the right front wheel (25) is measured The advance of the right front wheel (25) is c₁ ×tanθ, the lag of the rear sensing point of the right front wheel (25) is c₂ ×tanθ, the advance of the right rear wheel (27) is c₃ ×tanθ, the right rear wheel (27 ) The hysteresis of the post-induction point is c₄ ×tanθ. However, considering that the deviation angle of most vehicles is not large and θ is very small, it can be considered here that c₁ ×tanθ=c₂ ×tanθ, c₃ ×tanθ=c₄ ×tanθ. When the mobile trolley on the right is in four positions from right to left as shown in Figure 3, the distances from No. 2 laser range finder (6) to the diffuse reflection photoelectric switch (10) on the mobile trolley on the right are respectively L_f1 , L_f2 , L_r1 , L_r2 , the distance from No. 2 laser rangefinder (6) to the plane perpendicular to the direction of travel where the center of the right front wheel (25) is located is L_f , and to the right rear wheel (27) The distance L_r of the plane perpendicular to the direction of travel where the center is located, then

L_f＝(L_f1+c₁×tanθ+L_f2-c₂×tanθ)/2＝(L_f1+L_f2)/2L_f ＝(L_f1 +c₁ ×tanθ+L_f2 -c₂ ×tanθ)/2＝(L_f1 +L_f2 )/2

L_r＝(L_r1+c₃×tanθ+L_r2-c₄×tanθ)/2＝(L_r1+L_r2)/2L_r ＝(L_r1 +c₃ ×tanθ+L_r2 -c₄ ×tanθ)/2=(L_r1 +L_r2 )/2

设右侧轴距为L₂，则Let the right wheelbase be L₂ , then

L₂＝L_r-L_f＝(L_r1+L_r2)/2-(L_f1+L_f2)/2＝(L_r1+L_r2-L_f1-L_f2)/2L₂ =L_r -L_f =(L_r1 +L_r2 )/2-(L_f1 +L_f2 )/2=(L_r1 +L_r2 -L_f1 -L_f2 )/2

设左侧轴距为L₁，则同理可得左侧轴距L₁。Assuming that the left wheelbase is L₁ , the left wheelbase L₁ can be obtained similarly.

设汽车轴距为L，则Let the wheelbase of the car be L, then

L＝(L₁+L₂)/2L=(L₁ +L₂ )/2

3)采集轮距信号3) Collect wheel base signal

轴距测量完毕，车辆缓慢前行，开始测量汽车轮距。参阅图4与图5，汽车轮距测量原理为：车辆缓慢前行，当车辆前轮只挡住2号对射式光电开关(8)时，点阵显示屏(29)提示车辆稍进；只挡住了1号对射式光电开关(7)时，点阵显示屏(29)提示车辆稍退；当车辆前轮完全挡住1号对射式光电开关(7)和2号对射式光电开关(8)时，点阵显示屏(29)提示停车。此时3号激光测距仪(2)、4号激光测距仪(3)、5号激光测距仪(4)和6号激光测距仪(5)同时测量，得到相应端面的距离值。测量完毕，点阵显示屏(29)提示“测量后轮轮距车辆缓慢前进”。当车辆后轮完全挡住1号对射式光电开关(7)和2号对射式光电开关(8)时，3号激光测距仪(2)、4号激光测距仪(3)、5号激光测距仪(4)和6号激光测距仪(5)同时测量，得到相应端面的距离值。其中After the wheelbase measurement is completed, the vehicle moves forward slowly and starts to measure the wheelbase of the vehicle. Referring to Fig. 4 and Fig. 5, the principle of automobile wheelbase measurement is: the vehicle moves forward slowly, and when the front wheel of the vehicle only blocks the No. 2 through-beam type photoelectric switch (8), the dot matrix display screen (29) prompts the vehicle to advance slightly; When the No. 1 through-beam photoelectric switch (7) is blocked, the dot matrix display screen (29) prompts the vehicle to retreat slightly; when the front wheel of the vehicle completely blocks the No. 1 through-beam photoelectric switch (7) and the No. 2 through-beam photoelectric switch During (8), dot matrix display screen (29) prompts to stop. At this time, No. 3 laser range finder (2), No. 4 laser range finder (3), No. 5 laser range finder (4) and No. 6 laser range finder (5) measure at the same time to obtain the distance value of the corresponding end face . After the measurement, the dot-matrix display (29) prompts "measuring the rear wheel track vehicle to move forward slowly". When the rear wheel of the vehicle completely blocks No. 1 through-beam photoelectric switch (7) and No. 2 through-beam photoelectric switch (8), No. 3 laser range finder (2), No. 4 laser range finder (3), 5 No. 1 laser range finder (4) and No. 6 laser range finder (5) measure at the same time to obtain the distance value of the corresponding end face. in

B_f——前轮轮距B_f ——Front wheel track

B_r——后轮轮距B_r ——rear wheel track

S₁——3号激光测距仪(2)右侧到4号激光测距仪(3)左侧的距离S₁ ——the distance from the right side of No. 3 laser range finder (2) to the left side of No. 4 laser range finder (3)

S₂——4号激光测距仪(3)左侧到5号激光测距仪(4)右侧的距离S₂ ——the distance from the left side of No. 4 laser range finder (3) to the right side of No. 5 laser range finder (4)

S₃——5号激光测距仪(4)右侧到6号激光测距仪(5)左侧的距离S₃ ——the distance from the right side of No. 5 laser range finder (4) to the left side of No. 6 laser range finder (5)

B_f1——3号激光测距仪(2)右侧到左前轮(24)左表面的距离B_f1 ——the distance from the right side of the No. 3 laser rangefinder (2) to the left surface of the left front wheel (24)

B_r1——3号激光测距仪(2)右侧到左后轮(26)左表面的距离B_r1 ——the distance from the right side of the No. 3 laser rangefinder (2) to the left surface of the left rear wheel (26)

B_f2——4号激光测距仪(3)左侧到左前轮(24)右表面的距离B_f2 ——the distance from the left side of the No. 4 laser range finder (3) to the right surface of the left front wheel (24)

B_r2——4号激光测距仪(3)左侧到左后轮(26)右表面的距离B_r2 ——the distance from the left side of the No. 4 laser range finder (3) to the right surface of the left rear wheel (26)

B_f3——5号激光测距仪(4)右侧到右前轮(25)左表面的距离B_f3 ——the distance from the right side of the No. 5 laser range finder (4) to the left surface of the right front wheel (25)

B_r3——5号激光测距仪(4)右侧到右后轮(27)左表面的距离B_r3 ——the distance from the right side of the No. 5 laser rangefinder (4) to the left surface of the right rear wheel (27)

B_f4——6号激光测距仪(5)左侧到右前轮(25)右表面的距离B_f4 ——the distance from the left side of No. 6 laser rangefinder (5) to the right surface of the right front wheel (25)

B_r4——6号激光测距仪(5)左侧到右后轮(27)右表面的距离B_r4 ——the distance from the left side of No. 6 laser rangefinder (5) to the right surface of the right rear wheel (27)

前轮轮距B_f＝S₂+B_f2+(S₁-B_f1-B_f2)/2+B_f3+(S₃-B_f3-B_f4)/2Front wheel track B_f ＝S₂ +B_f2 +(S₁ -B_f1 -B_f2 )/2+B_f3 +(S₃ -B_f3 -B_f4 )/2

后轮轮距B_r＝S₂+B_r2+(S₁-B_r1-B_r2)/2+B_r3+(S₃-B_r3-B_r4)/2Rear wheel base B_r ＝S₂ +B_r2 +(S₁ -B_r1 -B_r2 )/2+B_r3 +(S₃ -B_r3 -B_r4 )/2

设B为汽车轮距，则Let B be the wheelbase of the car, then

B＝(B_f+B_r)/2B=(B_f +B_r )/2

4)通过重心位置动态检测算法计算出汽车重心位置4) Calculate the center of gravity position of the vehicle through the dynamic detection algorithm of the center of gravity position

根据数据采集系统(参阅图7)，所采集、处理后的信息，通过重心位置动态检测算法，计算出汽车重心位置：According to the data acquisition system (see Figure 7), the collected and processed information is used to calculate the center of gravity position of the vehicle through the dynamic detection algorithm of the center of gravity position:

(1)计算重心水平位置：参阅图6，设重心所在位置点为O、G₁为后轴载荷、G₁₁为左后轮载荷、G₁₂为右后轮载荷、G₂为两右轮载荷、G₂₁为右前轮载荷、L₁为左侧轴距、L为汽车轴距、L₂为右侧轴距、B为汽车轮距、B_f为前轮轮距、B_r为后轮轮距、a为重心至前轴中心线的距离、b为重心至后轴中心线的距离、c为重心至两左轮中心连线的距离、d为重心至两右轮中心连线的距离、G为汽车总重，则(1) Calculate the horizontal position of the center of gravity: refer to Figure 6, set the position of the center of gravity as O, G₁ is the rear axle load, G₁₁ is the left rear wheel load, G₁₂ is the right rear wheel load, and G₂ is the two right wheel loads , G₂₁ is the right front wheel load, L₁ is the left wheelbase, L is the vehicle wheelbase, L₂ is the right wheelbase, B is the vehicle track, B_f is the front wheel track, B_r is the rear wheel Wheelbase, a is the distance from the center of gravity to the centerline of the front axle, b is the distance from the center of gravity to the centerline of the rear axle, c is the distance from the center of gravity to the center line of the two left wheels, d is the distance from the center of gravity to the center line of the two right wheels, G is the gross weight of the vehicle, then

G₁＝G₁₁+G₁₂G₁ =G₁₁ +G₁₂

G₂＝G₂₁+G₁₂G₂ =G₂₁ +G₁₂

L＝(L₁+L₂)/2L=(L₁ +L₂ )/2

B＝(B_f+B_r)/2B=(B_f +B_r )/2

$\mathrm{<span><span>a</span>a</span>}<span><span>=</span>=</span>\frac{{\mathrm{<span><span>G</span>G</span>}}_{\mathrm{<span><span>1</span>1</span>}}}{\mathrm{<span><span>G</span>G</span>}}\mathrm{<span><span>L</span>L</span>}$

$\mathrm{<span><span>b</span>b</span>}<span><span>=</span>=</span>\mathrm{<span><span>L</span>L</span>}<span><span>-</span>-</span>\mathrm{<span><span>a</span>a</span>}<span><span>=</span>=</span>\mathrm{<span><span>L</span>L</span>}<span><span>-</span>-</span>\frac{{\mathrm{<span><span>G</span>G</span>}}_{\mathrm{<span><span>1</span>1</span>}}}{\mathrm{<span><span>G</span>G</span>}}\mathrm{<span><span>L</span>L</span>}$

$\mathrm{<span><span>c</span>c</span>}<span><span>=</span>=</span>\frac{{\mathrm{<span><span>G</span>G</span>}}_{\mathrm{<span><span>2</span>2</span>}}}{\mathrm{<span><span>G</span>G</span>}}\mathrm{<span><span>B</span>B</span>}$

$\mathrm{<span><span>d</span>d</span>}<span><span>=</span>=</span>\mathrm{<span><span>B</span>B</span>}<span><span>-</span>-</span>\mathrm{<span><span>c</span>c</span>}<span><span>=</span>=</span>\mathrm{<span><span>B</span>B</span>}<span><span>-</span>-</span>\frac{{\mathrm{<span><span>G</span>G</span>}}_{\mathrm{<span><span>2</span>2</span>}}}{\mathrm{<span><span>G</span>G</span>}}\mathrm{<span><span>B</span>B</span>}$

(2)计算重心高度：参阅图8，设汽车制动前的速度为u，惯性力F作用在重心点O处，惯性力在前、后桥上M、N处的分力分别为F₁和F₂。(2) Calculating the height of the center of gravity: refer to Figure 8, assuming that the speed of the vehicle before braking is u, the inertial force F acts on the center of gravity point O, and the components of the inertial force at M and N on the front and rear axles are respectively F₁ and_F2 .

在前轴载荷最大时刻，对前轮接地点列力矩方程：At the moment when the front axle load is maximum, the moment equation for the ground contact point of the front wheel is as follows:

F_Z2L+F₂h₂+F₁h₁-G′a＝0F_Z2 L+F₂ h₂ +F₁ h₁ -G'a＝0

其中                    h₁＝h-asinφwhere h₁ =h-asinφ

h₂＝h+bsinφh₂ ＝h+bsinφ

联立上式，化简得Simultaneously above formula, simplify

$\mathrm{<span><span>h</span>h</span>}<span><span>=</span>=</span>\frac{{\mathrm{<span><span>G</span>G</span>}}^{<span><span>\&prime;</span>\&prime;</span>}\mathrm{<span><span>a</span>a</span>}<span><span>-</span>-</span>{\mathrm{<span><span>F</span>f</span>}}_{\mathrm{<span><span>Z</span>Z</span>}\mathrm{<span><span>2</span>2</span>}}\mathrm{<span><span>L</span>L</span>}<span><span>-</span>-</span><span><span>(</span>(</span>{\mathrm{<span><span>F</span>f</span>}}_{\mathrm{<span><span>2</span>2</span>}}\mathrm{<span><span>b</span>b</span>}<span><span>-</span>-</span>{\mathrm{<span><span>F</span>f</span>}}_{\mathrm{<span><span>1</span>1</span>}}\mathrm{<span><span>a</span>a</span>}<span><span>)</span>)</span>\mathrm{<span><span>sin</span>sin</span>}\mathrm{<span><span>\&phi;</span>\&phi;</span>}}{{\mathrm{<span><span>F</span>f</span>}}_{\mathrm{<span><span>1</span>1</span>}}<span><span>+</span>+</span>{\mathrm{<span><span>F</span>f</span>}}_{\mathrm{<span><span>2</span>2</span>}}}$

又有there are

则重心高度为Then the height of the center of gravity is

其中：设φ为车身绕重心的角位移(rad)、K_f为前轴弹簧刚度(N/m)、K_r为后轴弹簧刚度(N/m)。在平板制动台上，检测程序根据采集轴重和制动力信号随时间变化关系的曲线可以直接得出弹簧刚度的值。设G₃为前轴载荷(N)、为平板制动台附着系数，h₁、h₂分别为前轴载荷最大时刻对应的前、后轴悬架弹簧高度(m)、h为重心高度(m)，F_Z1、F_Z2分别为前轴载荷最大时刻对应的地面对前、后轮的法向反作用力(N)，F_Xb1、F_Xb2分别为前轴载荷最大时刻对应的前、后轮的地面制动力(N)、G′为前轴载荷最大时刻对应的汽车总重(N)。in: Let φ be the angular displacement (rad) of the body around the center of gravity, K_f be the spring stiffness of the front axle (N/m), and K_r be the spring stiffness of the rear axle (N/m). On the plate brake table, the detection program can directly obtain the value of the spring stiffness according to the curve of the relationship between the collected axle load and the braking force signal with time. Let G₃ be the front axle load (N), is the adhesion coefficient of the plate brake table, h₁ and h₂ are the suspension spring heights of the front and rear axles corresponding to the moment of the maximum load on the front axle respectively (m), h is the height of the center of gravity (m), F_Z1 and F_Z2 are the front The normal reaction force (N) of the ground on the front and rear wheels corresponding to the moment of maximum axle load, F_Xb1 and F_Xb2 are the ground braking force (N) and G′ of the front and rear wheels corresponding to the moment of maximum front axle load respectively is the total vehicle weight (N) corresponding to the moment when the front axle load is maximum.

Claims (6)

1. A dynamic detection device for the gravity center position of an automobile based on a braking process comprises a wheel load, a braking force detection device, a wheel base measurement device and a data acquisition and processing system, and is characterized in that,

the axle load and braking force detection device comprises brake tables (16), catch wheels (13), No. 3 correlation type photoelectric switches (14), a braking force sensor (15) and an axle load sensor (12), wherein the brake tables (16) are supported by a back plate and a frame below the brake tables, the braking force sensor (15) is arranged on the left side and the right side of the front end of each brake table (16), the axle load sensor (12) is arranged below the brake tables (16), the catch wheels (13) are arranged on two sides of the brake tables (16), and the No. 3 correlation type photoelectric switches (14) are arranged on two sides of the middle of the brake tables (16);

the wheel base measuring device comprises a left side guide rail (21) and a right side guide rail (11), a movable trolley (30) arranged on the guide rails, a laser reflection plate (35) arranged at the top of the movable trolley, a diffuse reflection type photoelectric switch (34) arranged in the middle of the movable trolley and laser range finders respectively arranged in front of the left side guide rail and the right side guide rail;

the wheel track measuring device comprises No. 1 and No. 2 correlation photoelectric switches (7 and 8) arranged on the left side and the right side of the front end of the brake bedplate (16) and laser range finders arranged on the left side, the right side and the middle of the front end of the brake bedplate (16).

2. The device for dynamically detecting the position of the center of gravity of an automobile based on a braking process as claimed in claim 1, wherein the number of the brake table plates (16) is 4, the sum of the length and the width of each two brake table plates is determined according to the wheelbase and the width of the automobile, and the adhesion coefficient of the plate surface of the brake table plate (16) is more than 0.1; a gap of 0.2mm-0.3mm should be reserved between the braking force sensor (15) and the braking bedplate (16); 6 axle weight sensors (12) are arranged below each brake bedplate (16) and weigh 5000kg at the maximum.

3. The dynamic vehicle gravity center position detection device based on the braking process according to claim 1, wherein the left guide rail (21) and the right guide rail (11) are parallel to the driving center line; the diffuse reflection type photoelectric switch (34) is parallel to the ground, is vertical to the center line of the crane, and has a height not exceeding the lowest point of the hub, and the maximum effective distance of the diffuse reflection type photoelectric switch (34) is 1000 mm-1200 mm.

4. The device for dynamically detecting the position of the center of gravity of the automobile based on the braking process as claimed in claim 1, wherein the surface of the laser reflector (35) is perpendicular to the ground and perpendicular to the center line of the automobile, and a cross-shaped collimation center is carved at the center (31) of the laser reflector for calibration and inspection of laser; no. 1 laser range finder (1) is installed in the place ahead of left side guide rail (21), and No. 2 laser range finder (6) is installed at the front end of right side guide rail (11), and the light that 1 laser range finder (1) and No. 2 laser range finder (6) launched all should be on a parallel with driving central line and ground, will guarantee simultaneously in the whole motion stroke of portable dolly (30), the accurate center department on laser reflector panel (35) is located always to the point of irradiation of the two.

5. The device for dynamically detecting the gravity center position of the automobile based on the braking process according to claim 1, wherein the effective distance of the No. 1 and No. 2 correlation type photoelectric switches (7 and 8) is between 3500mm and 4000 mm; the laser range finder dress is on wheel alignment line (41), and 3, 6 laser range finder (2, 5) are installed respectively in the left and right sides, and 4, 5 laser range finder (3, 4) are installed in the centre, and the light that four laser range finder launched all should be perpendicular to driving central line and be on a parallel with ground, and 4, 5 laser range finder (3, 4) all should be close to driving central line as far as possible to prevent that the vehicle from opening the partial measurement can not reach.

6. The method for dynamically detecting the gravity center position of the automobile by using the dynamic detection device for the gravity center position of the automobile based on the braking process as claimed in claim 1 is characterized by comprising the following specific steps of:

1) zero setting of equipment in data acquisition and processing system, and acquisition of axle weight and braking force signals

When a vehicle enters a detection field, a dot matrix display screen (29) prompts the vehicle to run on the detection device at an initial speed of 5-10 kilometers per hour, when a front wheel of the vehicle passes through a No. 3 correlation photoelectric switch (14), the voltage of the No. 3 correlation photoelectric switch (14) is changed, the signal is received by an industrial personal computer (28), the axle weight and the dynamic axle weight and braking force of the vehicle measured by a braking force sensor are recorded, and the dot matrix display screen (29) is used for displaying braking; when the vehicle is completely static, the dot matrix display screen (29) displays the load of the left front wheel, the right front wheel, the load of the left rear wheel, the load of the right rear wheel and the total weight of the vehicle, and a curve of the time-varying relation between the axle load and the braking force signal appears on the display interface of the industrial personal computer (28);

2) collecting wheel base signals

When the vehicle is completely stationary, the movable trolley (30) moves from the front end of the guide rail to the rear end of the guide rail, when diffuse reflection type photoelectric switches (34) on the movable trolley (30) sense the front edges and the rear edges of the front tires and the rear tires, the voltage of the diffuse reflection type photoelectric switches starts to change, and the industrial personal computer (28) sends an instruction to the laser range finder according to a voltage change signal to measure the distances from the diffuse reflection type photoelectric switches (34) to the laser range finder at the four moments; when the movable trolley (30) contacts a travel switch, the movable trolley automatically returns to the initial position;

3) collecting track signals

The vehicle slowly moves forwards, when the front wheel of the vehicle completely blocks the No. 1 correlation type photoelectric switch (7) and the No. 2 correlation type photoelectric switch (8), the No. 3 laser distance meter (2), the No. 4 laser distance meter (3), the No. 5 laser distance meter (4) and the No. 6 laser distance meter (5) are simultaneously measured to obtain the distance value of the corresponding end face, and the rear wheel track measuring method is the same as that of the front wheel;

4) calculating the gravity center position of the automobile by a gravity center position dynamic detection algorithm

Distance from center of gravity to center line of front axle:

distance from center of gravity to center line of rear axle:

distance from center of gravity to line connecting centers of two left wheels:

distance from center of gravity to line connecting centers of two right wheels:

height of center of gravity:

wherein:let phi be the angular displacement of the vehicle body around the center of gravity, K_fIs the front axle spring rate, K_rIs the rear axle spring rate; let G be the total weight of the automobile₁Is rear axle load, G₂For two right wheel loads, G₃Is the front axle load, B is the automobile wheel track,Is the adhesion coefficient of the flat brake pad, L is the wheelbase of the vehicle, G' is the total weight of the vehicle corresponding to the moment when the front axle load is maximum, F_Z1、F_Z2The normal reaction force of the ground corresponding to the moment when the load of the front axle is maximum to the front wheel and the rear wheel respectively.