Multi-lane vehicle track identification and weight calculation method

Abstract

The invention discloses a multi-lane vehicle track identification and weight calculation method, which aims at the problems of vehicle track identification and weight calculation under the condition of multi-lane free flow in off-site law enforcement, and comprises the following steps of: arranging a plurality of weighing units, and carrying out loading point coordinate calculation and loading point motion vector calculation on each weighing unit to obtain a multi-lane vehicle track identification and weight calculation result; by comparing the motion vectors of the loading points of the weighing units when the vehicle passes through the weighing platform, the state of the weighing units is marked, the state when the vehicle passes through the weighing platform is identified according to the rule, the motion trail of the vehicle is identified, and the weight is calculated. According to real-time data, the weighing platform is used for vehicle track recognition and weight calculation, the method is highly compatible with the weighing process, lanes do not need to be distinguished, and vehicle recognition in the free flow driving state is truly achieved.

Description

Technical Field

[0001] The invention belongs to the field of traffic informatization and relates to a multi-lane vehicle trajectory recognition and weight calculation method. Background Art

[0002] As the main means of highway overweight control, the non-site enforcement system for overweight control plays an important role in scientific and technological overweight control. Since the non-site enforcement system for overweight control is used in the free flow of vehicles, there is no hard isolation between multiple lanes, and the driving state of vehicles is in a free flow state. During the weighing and enforcement process, when multiple vehicles pass through the scale, they may cross lanes, run parallel, press seams, travel in an S direction, drive diagonally, etc. The identification of vehicle trajectories becomes very important. If the trajectory state of the vehicle when passing through the scale can be accurately identified, the weighing results can be compensated and tracked according to the trajectory, providing support for the performance improvement of the non-site enforcement system. Summary of the invention

[0003] The purpose of the present invention is to provide a multi-lane vehicle trajectory recognition and weight calculation method, which solves the vehicle trajectory recognition and weight calculation problems in the multi-lane free flow situation in non-site law enforcement. When calculating the vehicle weight, the compression seam, the cross-lane and the oblique driving can be processed to eliminate interference and improve the weighing accuracy.

[0004] The technical solution adopted by the present invention is: a multi-lane vehicle trajectory identification and weight calculation method, characterized in that by arranging multiple weighing units, the loading point coordinates and loading point motion vectors are calculated for each weighing unit, and the loading point motion vectors of each weighing unit are compared when the vehicle passes through the weighing platform, and the weighing unit state is marked, and the state of the vehicle when passing through the weighing platform is identified according to its law, the vehicle motion trajectory is identified, and the weight is calculated; the specific implementation steps are as follows:

[0005] (I) Weighing unit layout

[0006] The entire scale is paved with full coverage of the road and consists of multiple independent weighing units to ensure that vehicles can pass through in free flow. Each weighing unit has 4 sensors arranged at each corner. The width of the weighing unit is 1m to 1.5m, ensuring that a single vehicle cannot be pressed on a weighing unit at the same time. Three cells can definitely allow a single vehicle to pass;

[0007] (II) Calculation of the coordinates of the weighing unit loading point

[0008] When the vehicle passes, the outputs of the four sensors of the weighing unit are WA, WB, WC and WD respectively. The coordinate system is established with the lower left corner of the weighing unit in the direction of travel. According to the size of the weighing unit and the installation position of the sensor, the coordinates of the four sensor loading points can be determined as A(X 1 ,Y 1 ),B(X2 ,,Y 2 ),C(X 3 ,Y 3 ),D(X 4 ,Y 4 ), and calculate the coordinates of the load point of the weighing unit as P(X P , Y P ),in

[0009]

[0010] (III) Motion vector and weight calculation of weighing unit loading point

[0011] According to the usage, the sensor output of each weighing unit is synchronously collected at a fixed frequency, and the loading point coordinates p of each weighing unit obtained in step (ii) are 1 …p n , by calculating the loading point position at each acquisition moment and the previous acquisition moment, the loading point motion vector of each weighing unit is obtained The formula is as follows

[0012]

[0013] By analogy, when the vehicle passes, we get 1 …t n The corresponding motion vector is Then with each moment t 1 …t n The corresponding four sensor outputs WA, WB, WC, and WD are added together to obtain the weighing unit weight W at the corresponding moment. 1 …W n ;

[0014] (IV) Weighing unit status mark

[0015] According to the calculation result of step (iii), starting from the weighing unit at one end of the road, it is judged whether the multiple weighing units are on the same axis and marked;

[0016] If it is the same axle, mark its weighing unit as the same axle cover. When weight transfer occurs, mark the direction of weight transfer so that the running track can be connected according to the mark in the end.

[0017] If a weighing unit is not on the same axis as the weighing units on both sides, it can be known that it is the superposition state of the two vehicles, and it is marked as the superposition state, so t can be obtained. 1 …t n Marking of weighing unit at the time;

[0018] For all weighing units covered by the same axis, according to the loading point coordinates of the weighing unit, when the Y-axis coordinate value is 0, it is marked as the up-axis moment of the axle of the weighing unit; when the Y-axis coordinate value is the length of the scale body, it is marked as the down-axis moment of the axle of the weighing unit;

[0019] The conditions for judging whether multiple weighing units are on the same axis are:

[0020] (1) The vector directions of the loading points of adjacent non-empty weighing units are exactly the same and the judgment range includes no more than three weighing units;

[0021] (2) If the Y-axis coordinate values ​​are the same but the X-axis coordinate values ​​are different, there is a weight transfer between adjacent weighing units, and the transferred weights are exactly the same.

[0022] (V) Identify vehicle movement trajectory and calculate weight

[0023] According to the marks of the start and end times of the weighing unit, the adjacent cells covered by the axle on the weighing unit are regarded as the same axle. According to the weighing unit marks at each moment, the weights of the weighing units covering the same axle are added to obtain the axle weight at that moment. When there are multiple axles in the superimposed state of a single weighing unit, the data is eliminated, or the non-superimposed weighing unit weights of the same axle are selected and doubled as the axle weight. The weights of all the moments when the axle passes are added to obtain the axle weight of each vehicle passing through the scale body; the weight of each axle of the vehicle is superimposed to obtain the vehicle weight, and at the same time, the motion vector set of the weighing units in the non-superimposed state in the time period is connected to obtain the vehicle's running trajectory and identify the vehicle's driving status.

[0024] Compared with the traditional method, the present invention has the following beneficial effects:

[0025] The present invention calculates the coordinates of the loading point of the weighing unit and the motion vector of the loading point in real time, and uses the weighing platform to identify the vehicle track and calculate the weight according to the real-time data. It is highly compatible with the weighing process, does not need to distinguish the lanes, and truly realizes the vehicle identification in the free-flow driving state. Different from the existing track identification using video and laser, it has lower cost and is less affected by environmental factors. At the same time, when calculating the vehicle weight, it can process the pressure seam, cross-lane, and oblique driving, eliminate interference, and improve the weighing accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of a scale unit under a one-way two-lane road;

[0027] Figure 2 It is a schematic diagram of the scale unit in a multi-vehicle situation. DETAILED DESCRIPTION

[0028] The present invention is fully described below in conjunction with the accompanying drawings. It is obvious that the accompanying drawings are only one application form of the present invention, not all applications.

[0029] 1. Weighing unit layout

[0030] See attached Figure 1 , each lane is 3.75m wide, each weighing unit is 1.5m wide and 1m long, the scale is divided into 5 weighing units, No. 1 to No. 5, and each weighing unit has a sensor at each of the four corners. The following takes an axis as an example to explain the entire recognition calculation process.

[0031] See attached Figure 2 In lane 1, there is one axle A1 of vehicle C1, which weighs 3000kg and has a single wheel of 1500kg. In lane 2, there is one axle A2 of vehicle C2, which weighs 6000kg and has a single tire of 3000kg. Figure 2 It can be seen that the speed of vehicle C2 is faster than that of vehicle C1, and the width of axles A1 and A2 is 2.5 m.

[0032] 2. Calculation of weighing unit loading point and motion vector

[0033] Take weighing unit No. 1 as an example, t 1 At this moment, the tire on one side of the A1 axis is loaded on the No. 1 weighing unit. The coordinates of the sensors of the No. 1 weighing unit are A(0,0), B(1500,0), C(1000,0), and D(1000,1500).

[0034] The weight at the moment of loading is assumed as follows:

[0035] WA WB WC WD <![CDATA[t 1 ]]> 1000 500 0 0 <![CDATA[t 2 ]]> 600 300 200 400

[0036]

[0037] According to the above formula, t 1 Load point P at time 1 The coordinates of

[0038] X 1 =(1000×0+500×1500+0×0+0×0) / (1000+500+0+0)=500,

[0039] Y 1 =(1000×0+500×0+0×1000+0×1000) / (1000+500+0+0)=0;

[0040] That is t 1 Load point P at time 1 The coordinates of are (500,0), and similarly t2 The coordinates of the loading point at the moment are P 2 (700, 400);

[0041] The motion vector calculation formula of the loading point of each weighing unit is as follows:

[0042]

[0043] Assume t 2 Yes 1 At the next acquisition moment, the motion vector of the loading point of the weighing unit is

[0044] According to the above algorithm, the loading point coordinates P and motion vectors of each non-empty weighing unit can be calculated in real time at each moment.

[0045] 4. Status marking and axle weight calculation

[0046] Assume that the A1 axis of the C1 vehicle and the A2 axis of the C2 vehicle pass through each weighing unit as shown in the following table:

[0047]

[0048]

[0049] From the above table, we can see that

[0050] t 1 Moment: Due to t 1 Load point P at time 1 The coordinates are (500,0), that is, the Y-axis coordinate value is 0, and the weighing unit No. 1 can mark the C1 car A1 axis as 0, and the C1 car A1 axis upper axis time can be marked as t 1 , t 1 The axle weight at the moment is No. 1. Since the A1 axle spans the No. 1 and No. 3 weighing units, it is necessary to 1 At this moment, the weights of weighing units 1 and 3 are added together, so the sum of the weights of weighing unit 3 is 1500+1500=3000kg;

[0051] t 2 Moment: Weight transfer occurs, and the process is marked as the transfer from weighing unit No. 1 to weighing unit No. 2. The transferred weight is equal, so it is still the same axis, t 2 The axle loads at this moment are No. 1 and No. 2. It is necessary to change t 2 At this moment, the weights of weighing units 1, 2, and 3 are added together, so the sum of the weights of weighing unit 3 is 700+800+1500=3000kg;

[0052] t 3Moment: Weighing unit 1 is empty, but because the coordinate value of the Y axis is not the weighing unit length 1000 when leaving weighing unit 1, it is determined that axis A1 has not completely left weighing unit 1;

[0053] t 4 Time: At this time, the A2 axle of the C2 car is weighed, and the No. 3 weighing unit is in a superposition state. The vectors of the No. 2 weighing unit and the No. 5 weighing unit are not equal, and there is no weight transfer, so it is marked as a superposition state. At the same time, the A1 axle weight of the C1 car is obtained by doubling the weight of the No. 2 weighing unit, that is, 1500*2=3000kg. At the same time, the Y-axis coordinate value of the No. 5 weighing unit is 0, and the time on the A2 axle is marked as t 4 At the same time, the weight of the A2 axis at this moment is the weight of the No. 5 weighing unit doubled 3000*2=6000kg;

[0054] t 5 Time: The Y-axis coordinate value of weighing unit 2 is the weighing unit length 1000, so it is marked as t 5 The moment A1 leaves weighing unit No. 2, and weighing unit No. 3 is still in the superposition state. Therefore, the weight of A1 shaft at this moment is doubled by weighing unit No. 2, 1500*2=3000kg; at the same time, the weight of A2 shaft at this moment is doubled by weighing unit No. 5, 3000*2=6000kg;

[0055] t 6 Moment: A1 axis is completely separated, the superposition state of weighing unit No. 3 disappears, and it can be directly determined as the same axis as weighing unit No. 5. The axle weight of A2 axis is the sum of weighing units No. 1 and No. 3, that is, 3000+3000=6000kg;

[0056] t 7 Time: The Y-axis coordinate value of weighing unit No. 3 is the weighing unit length 1000, marked as the lower axis time of A2 axis.

[0057] According to the mark, the calculation time of A1 axis is t 1 to 4 Between 2 to 3 The vehicle is in a compressed state, and the weight is calculated by three weighing units. 3 ~t 4 There are multiple vehicles in parallel, which can be eliminated or unilaterally supplemented according to needs. At the same time, the vehicle is driving diagonally. 1 to 4 The calculation of all the moments between the two shows that the weight of A1 axle is 3000kg. When A2 axle is weighed, there are multiple vehicles, but since the weighing unit of A1 axle has been determined before, A2 axle can also easily obtain its own weighing unit sequence and calculate the weight.

[0058] The vector trajectory connection of the non-superimposed weighing units of the axes can obtain the motion trajectory of the axes, and the states of multiple vehicles and their respective weights can be accurately separated in the process.

[0059] This diagram only analyzes the implementation process of one axis, but the vehicle's driving trajectory can be completed by connecting the driving trajectories of all its axes. In summary, the vehicle's driving trajectory can be obtained by repeating the above process, and in this process, it is not limited to a single vehicle passing through, and different vehicles, different weights, different speeds, and even vehicles with different driving directions can pass in parallel.

[0060] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A multi-lane vehicle trajectory recognition and weight calculation method, characterized in that: By arranging multiple weighing units, the loading point coordinates and loading point motion vectors are calculated for each weighing unit. By comparing the loading point motion vectors of each weighing unit when the vehicle passes through the weighing platform, the weighing unit status is marked, and the status of the vehicle when passing through the weighing platform is identified according to its rules, the vehicle motion trajectory is identified, and the weight is calculated. The specific implementation steps are as follows: (I) Weighing unit layout The entire scale body is paved with full coverage of the road to ensure that vehicles must pass under free flow conditions. The scale body is paved with multiple independent weighing units, and each weighing unit is equipped with 4 sensors at each corner; (II) Calculation of the coordinates of the weighing unit loading point When the vehicle passes, the outputs of the four sensors of the weighing unit are WA, WB, WC and WD respectively. The coordinate system is established with the lower left corner of the weighing unit in the direction of travel. According to the size of the weighing unit and the installation position of the sensor, the coordinates of the four sensor loading points can be determined as A(X1, Y1), B(X2,, Y2), C(X3, Y3), D(X4, Y4). Through the outputs of the four sensors WA, WB, WC and WD, the coordinates of the loading point of the weighing unit are calculated as P(X P , Y P ),in (III) Motion vector and weight calculation of weighing unit loading point According to the usage, the sensor output of each weighing unit is synchronously collected at a fixed frequency, and the loading point coordinates p1…p of each weighing unit obtained in step (ii) are n , by calculating the loading point position at each acquisition moment and the previous acquisition moment, the loading point motion vector of each weighing unit is obtained The formula is as follows By analogy, when the vehicle passes, we get each moment t1…t n The corresponding motion vector is Then, at each moment t1…t n The corresponding four sensor outputs WA, WB, WC, and WD are added together to obtain the weighing unit weight at the corresponding moment: W1…W n ; (IV) Weighing unit status mark According to the calculation result of step (iii), starting from the weighing unit at one end of the road, it is judged whether the multiple weighing units are on the same axis and marked; If it is the same axle, mark its weighing unit as the same axle cover. When weight transfer occurs, mark the direction of weight transfer so that the running track can be connected according to the mark in the end. If a weighing unit is not on the same axis as the weighing units on both sides, it can be known that it is the superposition state of the two vehicles, and it is marked as the superposition state, so t1…t n Marking of weighing unit at the time; For all weighing units covered by the same axis, according to the loading point coordinates of the weighing unit, when the Y-axis coordinate value is 0, it is marked as the up-axis moment of the axle of the weighing unit; when the Y-axis coordinate value is the length of the scale body, it is marked as the down-axis moment of the axle of the weighing unit; (V) Identify vehicle movement trajectory and calculate weight According to the marks of the start and end times of the weighing unit, the adjacent cells covered by the axle on the weighing unit are regarded as the same axle. According to the weighing unit marks at each moment, the weights of the weighing units covering the same axle are added to obtain the axle weight at that moment. When there are multiple axles in the superimposed state of a single weighing unit, the data is eliminated, or the non-superimposed weighing unit weights of the same axle are selected and doubled as the axle weight. The weights of all the moments when the axle passes are added to obtain the axle weight of each vehicle passing through the scale body; the weight of each axle of the vehicle is superimposed to obtain the vehicle weight, and at the same time, the motion vector set of the weighing units in the non-superimposed state in the time period is connected to obtain the vehicle's running trajectory and identify the vehicle's driving status.

2. The multi-lane vehicle trajectory recognition and weight calculation method according to claim 1, characterized in that: The width of each weighing unit ranges from 1m to 1.5m. A single vehicle cannot be on one weighing unit at the same time. Three weighing units must allow a single vehicle to pass.

3. The multi-lane vehicle trajectory recognition and weight calculation method according to claim 1, characterized in that: Step (IV) The conditions for determining whether multiple weighing units are on the same axis are: (1) The vector directions of the loading points of adjacent non-empty weighing units are exactly the same and the judgment range includes no more than three weighing units; (2) If the Y-axis coordinate values ​​are the same but the X-axis coordinate values ​​are different, there is a weight transfer between adjacent weighing units, and the transferred weights are exactly the same.

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