TWI508032B - Control method of traffic sign by utilizing vehicular network - Google Patents

Description

Using the control method of the vehicle communication system

The present invention relates to a method for controlling a number, and more particularly to a method for controlling a number using an in-vehicle communication system.

The traditional tactical control method is mainly fixed time regulation, so it cannot be dynamically adjusted according to the current traffic condition. On the other hand, the adjustable number is used to collect traffic information in the real environment by means of a detector, such as an induction coil, a magnetic sensor or an intersection recognition technique.

At present, a system using a WSN (Wireless Sensor Network) requires a large number of sensors. In addition, an RFID-based system requires an RFID reader to be installed in each section, and thus requires a large hardware construction cost. However, there are still many problems. For example, given a high priority to certain vehicles will increase the overall delay time of all vehicles; the need for turning information and the fairness of traffic flow. Furthermore, each road segment will usually have a shared right-turn lane, causing a straight-through vehicle to be blocked by a right-turning vehicle or a right-turning vehicle to be blocked by a straight-through vehicle. In particular, this type of mixed turn and straight traffic will cause intersections. The traffic of the car has dropped.

One of the objects of the present invention is that the length and sequence of the time can be adjusted according to the condition of the traffic flow.

One of the objects of the present invention is to increase the throughput of intersection traffic.

One of the objects of the present invention is to reduce greenhouse gases generated when a vehicle is idling at an intersection.

An embodiment of the present invention provides a signaling control method using an in-vehicle communication system, which is applicable to an intersection. The method includes: a pass rate calculation step, calculating a pass rate according to a driving parameter; and a moving type determining step, according to The driving parameter determines the moving type of one of the vehicles in one of the intersections; and the No. 1 decision step determines the next number of lights according to the passing rate and the moving category.

Please refer to FIG. 1. FIG. 1 is a schematic diagram showing an embodiment of a method for controlling the number of signals using the in-vehicle communication system of the present invention. In the present invention, the intersection I has i road segments and j lanes, i is a positive integer greater than 0, and j is a positive integer greater than zero. In the present embodiment, the intersection I has four sections A to D and eight lanes L1 to L8, and a plurality of vehicles are driven on the lanes L1 to L8.

Assume that each vehicle is equipped with an On Board Unit (hereinafter referred to as OBU), and each intersection I has a traffic signal controller with a network interface and a microprocessor, through the network on the vehicle. The network interface between the road interface and the intersection I can enable the number to obtain the driving parameters of each vehicle through the OBU on each vehicle, so that the microprocessor of the number can dynamically control the change of the intersection I. In an embodiment, the driving parameter further comprises an average acceleration value of one of the n vehicles (n is a positive integer greater than 0) passing through the intersection I, or a distance between the vehicles and a center point of the intersection, or a turn Message, or a driving reaction time, etc.

When the vehicle stops at the intersection because it waits for a red light, it will register with the number of the intersection I and transmit the driving parameters. When a registered vehicle passes a certain intersection, the vehicle will cancel the registration of the intersection I. Therefore, the number of the intersection I can collect the driving parameters of all the vehicles waiting at the intersection. Dynamically control the traffic light number.

The vehicle passing rate r _ij of the lane j on the road section i of the intersection I can be calculated as follows:

Where, n is the number of vehicles waiting in the driveway by the road section j i's, t _ij is the last one registered vehicles on the road is expected by the lane road section i i j through the intersection of I's time, which means by the time t _ij is expected intersection The time of the vehicle in the jth lane of the i-th road section of I is expected to pass the intersection I.

Please refer to FIG. 2A, which shows a schematic diagram of an embodiment of the vehicle of the present invention in a stationary state. For the sake of simplicity, take a lane here to explain, assuming that the number of the signal is red, the mth and nth are the first and the last stationary vehicle, so m=1, the mth car The average acceleration minimum value a _min = {a ₁ , a ₂ , ..., a _n } of each vehicle with the nth car can be regarded as the acceleration value of the nth car. Moreover, the distance between the nth car and the center point of the intersection I is d, and the moving time t of the nth car (the last car) on the road segment i satisfies the following formulas (2) and (3):

Where v is the speed of the nth car, since the vehicle is stationary from the first car to the last car, v=0. Next, assume that the first k carriage driving reaction time △ t _k may be derived n-th time by the expected carriage t _ij:

The acceleration of the last car (nth car) is limited by the slowest vehicle in front of it, so the acceleration of the slowest car can be regarded as the acceleration of the last car. When the vehicle is in the mobile queue, the vehicle takes priority in the current traffic light phase.

Please refer to FIG. 2B. FIG. 2B is a schematic diagram showing an embodiment of the vehicle of the present invention in a moving state. It is assumed that the signal light is a green light at this time, that is, some vehicles are in the moving queue, so m is not equal to 1 (meaning that m is not the first car), and the first car is moving, so some vehicles do not have the reaction time Δ t _{k of} driving, but the speed of the last car (nth car) is zero, and it is expected to pass The time t _ij will be relatively short.

Please refer to FIG. 2C. FIG. 2C is a schematic diagram showing an embodiment of the vehicle of the present invention in a moving state. When all the vehicles are in the mobile queue, it is assumed that the signal is green at this time, so the mth car is equal to the first n trolleys, and the speed is not zero.

Please refer to Figure 3A. Figure 3A shows a schematic diagram of the type of vehicle movement. In an embodiment of the present invention, there are four types of movements indicating the arrangement of traffic lights of a particular road segment: RIGHT_ONLY (ie, moving category 1), STRAIGHT_RIGHT (ie, moving category 2), LEFT_ONLY (ie, moving type 3), and ALL_THROUGH (ie, Move category 4). RIGHT_ONLY and LEFT_ONLY respectively indicate that the green light is given to the right turn and the left turn, meaning that the vehicles on the road are right-turning vehicles or left-turning vehicles; STRAIGHT_RIGHT means that the green light is scheduled to turn right and straight, meaning the road section These vehicles are straight-through vehicles or right-turning vehicles; ALL_THROUGH (ie, moving category 4) means that the green light is scheduled to turn right or left and straight, meaning that the road section The vehicle has a right-turning vehicle, a left-turning vehicle, and a straight-through vehicle.

Please refer to FIG. 3B. FIG. 3B shows the symbol phase matrix of an embodiment of the present invention. Each column indicates that the movement starts at a certain road segment i, and each row represents a certain traffic light number arrangement, and one or more mobile types can be set to pass the vehicle through the intersection. As shown in Fig. 3B, each column indicates that the movement starts from the i road segment, and each row indicates that the vehicle of one or more mobile categories can be set by the number of the road sign. Every unit =1 indicates in the time phase matrix S ^k that the green light is arranged on the lane j on the road segment i having the same traffic attribute (FA) and the mobile type; =0. In this embodiment, the time-phase matrix S=(S ⁰ , S ¹ , . . . , S ¹⁵ ) is preset in the memory of the intersection controller, please refer to the 3C diagram at the same time, and the present example design S ⁰ ,S ^1, ..., S ¹⁵ a total of sixteen matrix, intersection set of phase controller matrix ^{S = (S 0, S 1} , ..., S 15) during a selected phase matrix representation lights No. Phase, the selected phase matrix represents the green light setting of the next intersection I.

When the vehicle stops at the intersection I, it registers with the intersection controller and transmits the driving parameters of each vehicle, so that the intersection i controller obtains the pre-turning direction of each vehicle or the position in the lane. According to the driving parameters registered by each vehicle, the intersection controller will discharge the next green light phase and its duration, and this schedule will be completed before the current green light phase is invalid. Through the scheduling, the intersection controller first sets the FA of each lane according to the registration information of the lane j vehicle. In this embodiment, the FA starts from the leftmost lane to the rightmost lane, and each lane can have more In one FA. The rules for setting FA are as follows:

1. If there is no vehicle to go straight in the left turn lane, set LEFT_ONLY on the left turn lane and the other lanes to set STRAIGHT_RIGHT.

2. If only the vehicle that wants to go straight is on the left turn lane, set STRAIGHT_RIGHT is on all lanes.

3. If there is a vehicle that wants to go straight and turn left in the left turn lane, set ALL_THROUG on all lanes.

4. If there is no vehicle to go straight in the right turn lane, set RIGHT_ONLY in the right turn lane.

After the intersection controller sets the FA of all lanes, the intersection controller will generate a pass rate matrix R _{n × m} , where n is the number of sections at the intersection and m is the type of movement. Each R _{m × n} item R _ij can be calculated as the following equation (5):

Where l is the number of lanes on the road segment i, and Is the pass rate of the kth lane with the same FA and mobile behavior on the road segment i. Next, calculate each time phase matrix S ^k weight W ^k as follows,

Where S ^k is the kth time phase matrix in the time phase matrix set S = (S ¹ , S ² , ..., S ¹⁶ ), and 16 is the total number of time phase matrices in the matrix set. The intersection controller selects the time phase matrix S _max with the largest weight for the next green light phase to allow the maximum number of vehicles passing through the intersection. On the other hand, the shortest pass time after S _max is selected is the next green time T _green to keep the pass rate maximum.

It should be noted that the present invention can utilize the shortest green time T _min and the maximum green time T _max to avoid an excessively long or too short green time T _green . The S _max extension can prevent frequent interruptions of the same S _max .

Please refer to FIG. 4A, which shows a schematic diagram of the phases S ⁱ , S ^j , S ^k and S ^l in an embodiment. Among them, the light colored block indicates the green time, and the dark colored block indicates the red light time. In the present embodiment, the phase matrix S ⁱ has a higher pass rate, so the priority of the pass is always obtained. In order to avoid such a time-phase matrix with a higher pass rate always taking priority, we designed a preset time And the matrix A _nxm is generated. For time-phase matrices with lower pass rates, preset time It is the waiting time of the vehicle on the lane j of the road section i.

In addition, when the mobile type 4 (ALL_THROUGH) obtains the right of way, all other mobile categories are considered to have the right of way. Similarly, if the movement type 2 (STRAIGHT_RIGHT) obtains the right of passage, the movement type one (RIGHT_ONLY) also obtains the right of passage.

When the type of movement is one to four, the preset time When it is greater than or equal to the predefined threshold time T _age , the priority of the mobile category is increased by the following formula (7):

With the A matrix, the weight of each phase matrix S ^k can be calculated as shown in the following equation (8):

Please refer to FIG. 4B, which shows a schematic diagram of the phases S ⁱ , S ^j , S ^k and S ^l in one embodiment. Figure 4B shows that even with the A _ij matrix, the time-phase matrices S ⁱ and S ^j can still take the pass rights in turn until the phase-phase matrices S ^k and S ^{l are} prioritized. In order to avoid certain time-phase matrices with higher pass rates and to obtain the right of passage, the present invention can utilize a phase-served matrix P _nxm so that the used phase matrix can no longer be used. Repeat the right of passage until all other mobile categories at the intersection have been used.

In this embodiment, the type of movement of the time-phase matrix that has been used is masked, so its pass rate is not taken into account by the weight calculation of the time-phase matrix, but the arrangement of the green light extension is in some specific phases. Allowed. The phase of the movement that has been used is only obscured when the green light is scheduled for the unused phase. When an unused phase matrix has priority, the phase service matrix masks the used phase matrix as follows:

Through the time-phase service matrix, the weight of each time-phase matrix S ^k can be calculated as the following equation (10):

If all elements of matrix P are masked to zero, all element values will be reset to 1. Please refer to FIG. 4C at the same time. As shown in FIG. 4C, through the phase service matrix, the problem that the phase with higher pass rate repeatedly regains priority is solved.

Referring to FIG. 5, FIG. 5 is a flow chart showing a method for controlling the locomotive using the in-vehicle communication system of the present invention, which includes the following steps: step S500: start; step S501: register and transmit driving parameters; step S502: according to driving The parameter is used to calculate a pass rate; step S503: determining a moving type of one of the vehicles in one of the intersections according to the driving parameter; and step S504: determining the next number of lights according to the passing rate and the moving type.

Step S505: The vehicle passes the intersection and cancels the registration.

In summary, the present invention utilizes the driving parameters of each vehicle to adjust the schedule of the intersection number, so that the traffic passing rate of each intersection can be maximized, and the number scheduling of each section can be fairly distributed. The present invention has been described above by way of examples, and the scope of the invention is not limited thereto, and various modifications and changes can be made by those skilled in the art without departing from the scope of the invention.

I‧‧‧ junction

O‧‧‧ Center Point

A~D‧‧‧ section

L1~L8‧‧" lane

S500~S505‧‧‧Steps

Fig. 1 is a view showing an embodiment of a method for controlling a number of signals using the in-vehicle communication system of the present invention.

Fig. 2A is a view showing an embodiment of the vehicle of the present invention in a stationary state.

Fig. 2B is a view showing an embodiment of the vehicle of the present invention in a moving state.

Fig. 2C is a view showing an embodiment of the vehicle of the present invention in a moving state.

Figure 3A shows a schematic diagram of the type of vehicle movement.

Fig. 3B shows a symbol phase matrix of an embodiment of the present invention.

Fig. 3C shows a symbol phase matrix of an embodiment of the present invention.

Figure 4A shows a schematic diagram of the phases S ⁱ , S ^j , S ^k and S ^l in one embodiment.

Figure 4B shows a schematic diagram of the phases S ⁱ , S ^j , S ^k and S ^l in one embodiment.

Figure 4C shows a schematic diagram of the phases S ⁱ , S ^j , S ^k and S ^l in one embodiment.

Fig. 5 is a flow chart showing the flow control method of the present invention using the in-vehicle communication system.

I‧‧‧ junction

O‧‧‧ Center Point

A~D‧‧‧ section

L1~L8‧‧" lane

Claims (10)

A method for controlling the use of the in-vehicle communication system is applicable to a road junction, the method comprising: a pass rate calculation step, calculating a pass rate according to a driving parameter; a moving type determining step, determining the intersection according to the driving parameter One of the vehicles of one lane moves the category; and a number one decision step, based on the pass rate and the mobile category to determine the next number of lights. The method of claim 1, wherein the driving parameter further comprises an average acceleration value of one of the n vehicles (n is a positive integer greater than 0) passing through the intersection, or the vehicles and the intersection a distance from a center point, or a turn message, or a reaction time; wherein the turn message is a message that the vehicles are not traveling straight through the intersection; and the driving reaction time is required for the vehicles to be stationary to mobile Average time. The method of claim 2, wherein the intersection has i road segments and j lanes, i is a positive integer greater than 0, j is a positive integer greater than 0; an expected transit time t _{ij is} the intersection The time when the vehicle of the jth lane in the i-th road section is expected to pass the intersection; and the passing rate r _{ij is} the number of passing vehicles of the j-th lane in the i-th road section within the expected passage time t _ij The ratio of the expected passage time t _ij . The method of claim 3, wherein the pass rate calculation step further comprises: obtaining a minimum acceleration value a _min according to the average acceleration value of the n vehicles, according to the location of the last vehicle a position of the center point and the minimum acceleration value a _min to calculate a movement time t of one of the n vehicles; and if the n vehicles are stationary, according to the movement time t and the n vehicles The reaction time calculates the expected transit time t _ij ; if the n vehicles are non-stationary, the expected transit time t _{ij is} calculated according to the moving time t; wherein the pass rate of the jth lane in the i th road segment r _ij =n/t _ij . The method of claim 4, wherein the moving category determining step comprises: determining the movement type of the vehicles of each road segment according to the turning information of the vehicles in each lane. The method of claim 5, wherein the mobile category comprises: a first mobile category, the vehicles of the road segment are right-turning vehicles; and a second mobile category, the vehicles of the road segment are a straight-through vehicle or a right-turning vehicle; a third type of movement, the vehicles of the road section are left-turning vehicles; and a fourth type of movement, the vehicles of the road section having a right-turning vehicle, a left-turning vehicle, and a straight-through vehicle . The method of claim 6, wherein the determining step comprises: determining the running light number of the number according to the moving type of each road segment and the passing rate r _ij ; wherein the number of the running signal is Maximize the number of vehicles passing through the intersection. The method of claim 7, wherein the method further comprises: a fairness adjustment step, according to the operation time of one of the number of the running lights of the intersection, so that each lane maintains a vehicle passing through the intersection . The method of claim 8, wherein the operation time is adjusted when the operation time is greater than a first preset value. The method of claim 9, wherein the operation time is adjusted when the operation time is greater than a second preset value.