CN104228877A - Modern tram intersection signal control pre-warning method and pre-warning system - Google Patents

Abstract

The present invention provides a modern streetcar crossing signal control and early warning method, comprising the following steps: based on an RFID device installed at a fixed position, updating the tram operation information; based on the RFID electronic tags at the head and tail of the tram through RFID reading Calculate the average speed information of the tram based on the time of the sensor and the length information of the tram body; calculate the _tram The estimated time for the tram to arrive at the downstream adjacent intersection; obtain the clearing time and safety reserve time of the downstream intersection according to the geometric type of the downstream adjacent intersection; calculate the estimated time for the tram to arrive at the downstream adjacent intersection based on the previous steps, and the downstream The sum of the clearing time and the safety reserve time near the intersection is used to determine whether there is a risk of conflict. The invention also relates to a modern streetcar intersection signal control early warning system.

Description

Early warning method and early warning system for signal control of modern tram crossing

technical field

The present invention relates to the technical field of modern rail train operation early warning, in particular to a modern tramway intersection signal control early warning method and early warning system

Background technique

Modern trams are rail trains designed with intelligent rail transit technology. They belong to a new generation of conventional public transportation. They have the characteristics of fast running speed, low environmental pollution, low construction cost, and good appearance. It does not need to establish a completely independent right of way, and can be mixed with ordinary ground traffic. On the one hand, it reduces the shortage of land resources, but at the same time it brings potential safety hazards. In particular, at some intersections, trams need priority right of way, which will inevitably affect other traffic flows at the intersection, and even cause traffic conflicts and road traffic accidents. Therefore, the intelligent control of intersection signals of modern trams is a hot and difficult issue in current research.

At present, trams in some areas of the country bypass the intersection by opening special roads or building elevated roads at the intersection, and adopt the method of space separation to avoid conflicts. This is the safest method, but the construction cost is huge. For example, the domestic The trams built in Hunnan New District solve the problem of trams passing through intersections in this way. In addition, trams in some foreign regions adopt the method of joint control with intersection signals. Specifically, the position of the tram is determined according to the power supply interval of the tram through the control of the tram management center, and then it is judged When the tram passes the intersection, control the signal at the intersection, so that when the tram passes the intersection, the priority of modern trams can be realized. For example, Siemens, Huawei, etc. are currently engaged in research work in this area. These The technology has been tried and used in some western countries, but some problems have also appeared. At present, there is no perfect solution to solve the problem of signal control at tram intersections from the aspect of signal control technology.

In view of this, more research is needed to solve the problem of signal control of trams passing through intersections with more modern technology and mature solutions.

Contents of the invention

The purpose of the present invention is to provide a modern tramway intersection signal control early warning method and early warning system, which can realize the intelligent signal control of modern tramways passing through ground public intersections, and can reduce the risk of conflicts between tramways and intersection traffic flows. probability.

The above objects of the invention are achieved by the technical features of the independent claims, which the dependent claims develop in an alternative or advantageous manner.

In order to achieve the above object, the technical scheme adopted in the present invention is as follows:

A kind of modern streetcar crossing signal control early warning method, its realization comprises the following steps:

Step 1. Update the running information of the tram based on the RFID device installed at the fixed position: read the RFID electronic tag of the tram through the RFID reader installed at the fixed position to update the running information of the tram, wherein the RFID electronic tag is installed At the head and tail of the tram, the RFID reader is fixedly installed next to the track of the tram;

Step 2, based on the time t i1 when the RFID electronic tag at the head of the tram passes through the RFID reader, the time _{t i2 when} the RFID electronic tag at the rear of the tram passes through the RFID reader, and the body of the tram collected in step 1 Length information Sq, calculate the average speed information v _i of the tram from time t _i to time t _i2 :

Step 3. Based on the above-mentioned average speed information v _i of the tram and the distance S _i between the RFID reader currently installed beside the track and the downstream adjacent intersection, calculate the estimated time t _min for the tram to reach the downstream adjacent intersection _(i) :

Step 4. Obtain the clearing time t ₀ and the safety reserve time t ₁ of the downstream intersection according to the geometric type of the downstream adjacent intersection;

Step 5. Based on the previous steps, calculate the estimated time t _min(i) for the tram to arrive at the downstream adjacent intersection, as well as the clearing time t ₀ and the safety reserved time t ₁ for the downstream adjacent intersection, and determine whether there is a risk of conflict:

If the estimated time t _min(i) for the tram to arrive at the downstream adjacent intersection is greater than the sum t ₀ +t ₁ of the aforementioned downstream adjacent intersection clearing time t ₀ and safety reserved time t ₁ , it is determined that there is no risk, Return to the previous step 1;

If the estimated time t _min(i) for the tram to arrive at the downstream adjacent intersection is less than or equal to the sum t ₀ +t ₁ of the aforementioned downstream adjacent intersection clearing time t ₀ and safety reserved time t ₁ , then it is determined that there is a risk , to issue an early warning signal.

In a further embodiment, the foregoing method further includes:

When it is determined at a certain sequence time t _i , if the estimated time t _min(i) of the tram arriving at the downstream adjacent intersection is less than or equal to the sum of the aforementioned downstream adjacent intersection clearance time t ₀ and the safety reserved time t ₁ When t ₀ + t ₁ , it is determined that there is a traffic conflict between the tram and the adjacent downstream intersection, and a sound and/or light signal is sent to the downstream adjacent intersection, and feedback is given through the display screen and/or loudspeaker installed next to the intersection. come out.

In a further embodiment, the foregoing method further includes:

When it is determined that there is a traffic conflict between the tram and the adjacent downstream intersection, the control will forcibly switch the signal of the downstream adjacent intersection, and the downstream adjacent intersection will enter the state of clearing the road with a yellow light, prohibiting vehicles outside the intersection from entering the intersection, and broadcasting to notify that they have passed the intersection Vehicles on the stop line leave the intersection as soon as possible; and after the end of the aforementioned intersection clearance time, control the retractable fence at the entrance of the intersection to physically isolate the adjacent intersection downstream.

In a further embodiment, the foregoing method further includes:

In the aforementioned method, when it is determined that there is a traffic conflict between the tram and the downstream adjacent intersection at a certain sequence time t _i , an early warning signal is sent to the remote through a network.

According to the improvement of the present invention, also propose a kind of modern streetcar intersection signal control early warning system, this early warning system comprises:

The modern tram operation information collection device includes an RFID reader for monitoring the RFID electronic tags installed at the front and rear of the tram, wherein: the RFID electronic tag stores the tram number information, and the aforementioned RFID reader installed in a fixed position alongside the tramway;

one or more processors for controlling the operation of the early warning system;

at least one memory for storing data and program instructions for use by the one or more processors configured to execute the program instructions for:

Controlling the modern tram operation information collection device based on the RFID reader installed in a fixed position updates the tram operation information; and based on the collected data, perform the following processing:

a) Based on the time t _i1 of the collected tram head RFID electronic tag passing through the RFID reader, the time t _i2 of the tram tail RFID electronic tag passing through the RFID reader, and the length information Sq of the tram body, calculate The average speed information v _i of the tram from time t _i to time t _i2 :

b) Calculate the estimated time t _{min ( i )} :

c) Obtain the clearing time t ₀ and the safety reservation time t ₁ of the downstream intersection according to the geometric type of the downstream adjacent intersection;

d) Based on the estimated time t _min(i) of the arrival of the tram at the downstream adjacent intersection, as well as the clearing time t ₀ and the safety reserved time t ₁ at the downstream adjacent intersection, determine whether there is a risk of conflict:

If the estimated time t _min(i) for the tram to arrive at the downstream adjacent intersection is greater than the sum t ₀ +t ₁ of the aforementioned downstream adjacent intersection clearing time t ₀ and safety reserved time t ₁ , it is determined that there is no risk;

If the estimated time t _min(i) for the tram to arrive at the downstream adjacent intersection is less than or equal to the sum t ₀ +t ₁ of the aforementioned downstream adjacent intersection clearing time t ₀ and safety reserved time t ₁ , then it is determined that there is a risk , to issue an early warning signal.

As can be seen from the technical scheme of the present invention above, the beneficial effects of the present invention are:

1, in the scheme of the present invention, designed intersection signal intelligent control and early warning system for modern streetcar, adopt new early warning algorithm, obtain the operation of current modern streetcar by setting the monitoring point of RFID monitor based on modern streetcar Speed and location information, and then estimate the time when the modern tram arrives at the intersection, and compare it with the clearing time of the downstream intersection and the reserved safety time, and give an early warning according to the comparison result;

2. In the solution of the present invention, the calculation amount of the early warning algorithm is small, and the state quantity of modern trams is continuously updated, so that early warning can be carried out without interruption, and the timeliness and continuity of early warning can be improved;

3, in the scheme of the present invention, on the selection of modern tram running information collection device, can adopt the mature RFID equipment in the prior art (such as the high-frequency RFID equipment that Siemens produces), conveniently installed in the train of rapid operation , Accurate information transmission, improve system positioning and early warning accuracy.

Description of drawings

Fig. 1 is a block diagram of a preferred embodiment of the present invention.

Detailed ways

In order to better understand the technical content of the present invention, specific embodiments are given together with the attached drawings for description as follows.

As shown in Figure 1, according to a preferred embodiment of the present invention, a kind of modern streetcar crossing signal control early warning method, its realization comprises the following steps:

Step 1. Update the running information of the tram based on the RFID device installed at the fixed position: read the RFID electronic tag of the tram through the RFID reader installed at the fixed position to update the running information of the tram, wherein the RFID electronic tag is installed At the head and tail of the tram, the RFID reader is fixedly installed next to the tram track;

Step 2, based on the time t i1 when the RFID electronic tag at the head of the tram passes through the RFID reader, the time _{t i2 when} the RFID electronic tag at the rear of the tram passes through the RFID reader, and the body of the tram collected in step 1 Length information Sq, calculate the average speed information v _i of the tram from time t _i to time t _i2 :

Step 3. Based on the above-mentioned average speed information v _i of the tram and the distance S _i between the RFID reader currently installed beside the track and the downstream adjacent intersection, calculate the estimated time t _min for the tram to reach the downstream adjacent intersection _(i) :

Step 4. Obtain the clearing time t ₀ and the safety reserve time t ₁ of the downstream intersection according to the geometric type of the downstream adjacent intersection;

Step 5. Based on the previous steps, calculate the estimated time t _min(i) for the tram to arrive at the downstream adjacent intersection, as well as the clearing time t ₀ and the safety reserved time t ₁ for the downstream adjacent intersection, and determine whether there is a risk of conflict:

If the estimated time t _min(i) for the tram to arrive at the downstream adjacent intersection is greater than the sum t ₀ +t ₁ of the aforementioned downstream adjacent intersection clearing time t ₀ and safety reserved time t ₁ , it is determined that there is no risk, Return to the previous step 1;

If the estimated time t _min(i) for the tram to arrive at the downstream adjacent intersection is less than or equal to the sum t ₀ +t ₁ of the aforementioned downstream adjacent intersection clearing time t ₀ and safety reserved time t ₁ , then it is determined that there is a risk , to issue an early warning signal.

As shown in Figure 1, using the above scheme, the existing high-precision RFID reader and electronic tag can be used to collect the running data of the tram for a certain period of time, and then calculate its average speed, and use the average speed to Estimate the shortest time to arrive at the next intersection, and get the early warning result by comparing with the sum of the clearing time and safety time of the intersection, and when the aforementioned data is collected, the position of the RFID reader is fixed and located at the intersection Next to the predetermined orbital position upstream of the mouth, so as to realize pre-forecast, processing and judgment early warning.

Using the early warning scheme of the aforementioned embodiment, on the one hand, the information transmission is timely, and the running speed of the modern tram and the time to reach the intersection can be evaluated in real time, which can achieve the purpose of timeliness; on the other hand, through continuous collection and real-time judgment, The effect of continuous real-time early warning can be achieved.

As an optional implementation, the modern tram running data in the aforementioned steps can be collected in the following manner:

Read the RFID electronic tags installed at the head and tail of the tram through the RFID reader to obtain information such as the current modern tram formation, body length, vehicle number, etc.;

Through the RFID reader installed next to the tram track, the information such as the running speed and position of the modern tram passing through the current position is monitored.

In the present embodiment, the clearing time t of the downstream intersection referred to in the aforementioned step ₆ (refers to prohibiting the vehicles outside the intersection from entering the intersection, and the time when the vehicles that have passed the intersection stop line to leave as soon as possible) and the safety reserved time t ₁ , it can be set according to the actual geometry of the intersection, for example, it can be set as:

The clearing time t ₀ at the intersection of the tram line and the expressway can be set to 7-10s, and the safety reserve time t ₁ can be set to 10-15s;

The clearing time t ₀ at the intersection of the tram line and the main road can be set to 7-10s, and the safety reserve time t ₁ can be set to 10-15s;

The clearing time t ₀ at the intersection of the tram line and the secondary trunk road can be set to 5-7s, and the safety reserved time t ₁ can be set to 8-12s;

The clearing time t ₀ at the intersection of the tram line and the branch road can be set to 5-7s, and the safety reserve time t ₁ can be set to 5-8s.

The different intersection clearing time and safety reserve time set in this embodiment result in changing the traffic operation efficiency of the traffic intersection. The more time for clearing the road, the longer the safety reserve time and the higher the safety degree. But the intersection efficiency is lower.

As an optional implementation manner, in the foregoing method, further comprising:

When it is determined at a certain sequence time t _i , if the estimated time t _min(i) of the tram arriving at the downstream adjacent intersection is less than or equal to the sum of the aforementioned downstream adjacent intersection clearance time t ₀ and the safety reserved time t ₁ When t ₀ + t ₁ , it is determined that there is a traffic conflict between the tram and the adjacent downstream intersection, and a sound and/or light signal is sent to the downstream adjacent intersection control, and the feedback is given by the display screen and/or loudspeaker installed next to the intersection. Come out, signal to the driver who is going to pass the intersection, and remind him to pay attention.

As an optional mode, the aforementioned method further includes:

When it is determined that there is a traffic conflict between the tram and the adjacent downstream intersection, the control will forcibly switch the signal of the downstream adjacent intersection, and the downstream adjacent intersection will enter the state of clearing the road with a yellow light, prohibiting vehicles outside the intersection from entering the intersection, and broadcasting to notify that they have passed the intersection Vehicles on the stop line leave the intersection as soon as possible; and after the end of the aforementioned intersection clearance time, control the retractable fence at the entrance of the intersection to physically isolate the adjacent intersection downstream.

In some other embodiments, when it is determined that at a certain sequence time t _i , it is determined that there may be a risk of conflict between the modern tram and the adjacent downstream intersection, it can also be sent to the tram through a dedicated network, such as a dedicated network for the tram system. The special monitoring platform for the tram system sends early warning information to forecast the conflict risk between the current tram and the adjacent downstream intersection, so as to facilitate timely early warning and take emergency measures in advance, such as through the voice interaction system on the road/the interception prompt of the traffic police on the road, etc. , to reduce the risk of collision accidents between trams and other vehicles at intersections.

In some other embodiments, when it is determined that at a certain sequence time t _i , it is determined that there may be a risk of conflict between the modern tram and the adjacent downstream intersection, a network, such as the Internet (Internet), may be sent to a remote monitoring center or The monitoring room sends an early warning signal, and then the monitoring center or the monitoring room can broadcast or specifically issue an early warning signal to a specific intersection and tram.

According to the present disclosure, as shown in Figure 2, a modern streetcar intersection signal control early warning system includes:

The modern tram operation information collection device 10 includes an RFID reader 12 for monitoring the RFID electronic tags installed at the front and rear positions of the tram, wherein: the RFID electronic tag stores the tram number information, and the aforementioned RFID reader The writer (12) is installed in a fixed position next to the tram track;

one or more processors 20 for controlling the operation of the early warning system;

At least one memory 60 for storing data and program instructions used by the one or more processors 20 configured to execute the program instructions for:

Control described modern tram operation information collection device 10 to update tram operation information based on the RFID reader 12 installed in a fixed position; and based on the collected data, perform the following processing:

a) Based on the time t _i1 of the collected tram head RFID electronic tag passing through the RFID reader, the time t _i2 of the tram tail RFID electronic tag passing through the RFID reader, and the length information Sq of the tram body, calculate The average speed information v _i of the tram from time t _i to time t _i2 :

b) Calculate the estimated time t _{min ( i )} :

c) Obtain the clearing time t ₀ and the safety reservation time t ₁ of the downstream intersection according to the geometric type of the downstream adjacent intersection;

d) Based on the estimated time t _min(i) of the arrival of the tram at the downstream adjacent intersection, as well as the clearing time t ₀ and the safety reserved time t ₁ at the downstream adjacent intersection, determine whether there is a risk of conflict:

If the estimated time t _min(i) for the tram to arrive at the downstream adjacent intersection is greater than the sum t ₀ +t ₁ of the aforementioned downstream adjacent intersection clearing time t ₀ and safety reserved time t ₁ , it is determined that there is no risk;

If the estimated time t _min(i) for the tram to arrive at the downstream adjacent intersection is less than or equal to the sum t ₀ +t ₁ of the aforementioned downstream adjacent intersection clearing time t ₀ and safety reserved time t ₁ , then it is determined that there is a risk , to issue an early warning signal.

At least two RFID electronic tags are set on each tram, which are respectively installed at the head and tail of the modern tram to store the serial number information of the tram.

Preferably, the modern tram operation information collection device 10 includes at least one RFID reader 12, which is fixedly installed within 1 meter beside the tram track, and collects tram operation data, including the current position of the tram information and time information passing through the at least one RFID reader 12.

The early warning system also includes a traffic signal device 50 for controlling traffic signals at the intersection, connected to the one or more processors 20 . The traffic signal device 50, for example, can adopt The traffic signal produced by the company.

As mentioned above, the smaller the installation interval of the information collection device 10 of the tram, the smaller the evaluation time interval of the speed of the tram, and the more accurately the running speed of the tram can be estimated and the downstream approaching The estimated time of the intersection, so that the calculation process of the above a)-d) is closer to the actual situation, so that it can more truly reflect the possible conflict risk between the modern tram and the adjacent intersection downstream.

The aforementioned one or more processors 20, as a control and processing device, can be used to control the signal mode of the aforementioned intersection signal device 50 on the one hand, and can also be used to call the information collected by the modern tram operation information collection device 10 on the other hand. Data and program instructions are used for calculation and early warning judgment. Its calculation process and early warning judgment are as mentioned above.

In this embodiment, preferably, one or more processors 20 are realized by a single-chip microcomputer, of course, in other embodiments, they can also be realized by a microprocessor, for example or Production of microprocessors.

One or more processors 20 are connected with the aforementioned modern tram operation information collection device 10 through data lines and data interfaces.

As a preferred embodiment, as shown in Figure 2, the modern tram crossing warning system also includes an indicating device 21, such as an LED display, or an LED indicator light, connected to the one or more processors 20, for It is used to monitor the running status of the modern tram crossing early warning system, such as whether the running status of the modern tram running information collection device 10 is abnormal, whether the data connection between the modules is smooth, etc., through text boxes or LED indicators to Appropriate form for instructions.

In some other embodiments, the warning system can also be provided with an operation panel, such as a touch-sensitive operation panel, or a push-input type operation panel, for inputting operation instructions.

As a preferred embodiment, as shown in Figure 2, the early warning system also includes a wireless communication device 40 (such as a 3G communication module), which is connected to the one or more processors 20, through access to the Internet (Internet) Or a dedicated network (such as a dedicated network for trams), which sends early warning information to the command center, monitoring center or monitoring room. As mentioned above, it is predicted that there is a risk of conflict between the current tram and the adjacent downstream intersection, so as to facilitate timely decision-making. Early warning and emergency measures in advance to reduce the possibility of road traffic accidents.

As shown in Fig. 2, as an optional implementation, the modern streetcar intersection warning system also includes a speaker 30, when the one or more processors 20 determine that there is a risk of conflict between the streetcar and the adjacent downstream intersection , control the loudspeaker 30 to perform an early warning alarm, such as a buzzer or a voice alarm.

In another embodiment, as shown in FIG. 3 , the speaker 30 in FIG. 2 can also be replaced by an optical feedback device 31, which can be configured as an LED array, or a two-color display LED, or an LED Lights, connected to the one or more processors 20, when the one or more processors 20 determine that there is a risk of conflict between the tram and the downstream adjacent intersection, control the light feedback device 31 to flash and change color display etc. to feed back early warning information.

In some other embodiments, the loudspeaker 30 and the optical feedback device 31 in the aforementioned FIGS. 2 and 3 can be set at the same time, and the warning information can be fed back at the same time.

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Those skilled in the art of the present invention can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be defined by the claims.

Claims (9)

1. A modern streetcar crossing signal control early warning method is characterized in that its realization may further comprise the steps: Step 1. Update the running information of the tram based on the RFID device installed at the fixed position: read the RFID electronic tag of the tram through the RFID reader installed at the fixed position to update the running information of the tram, wherein the RFID electronic tag is installed At the head and tail of the tram, the RFID reader is fixedly installed next to the tram track; Step 2, based on the time t i1 when the RFID electronic tag at the head of the tram passes through the RFID reader, the time _{t i2 when} the RFID electronic tag at the rear of the tram passes through the RFID reader, and the body of the tram collected in step 1 Length information Sq, calculate the average speed information v _i of the tram from time t _i to time t _i2 : Step 3. Based on the above-mentioned average speed information v _i of the tram and the distance S _i between the RFID reader currently installed beside the track and the downstream adjacent intersection, calculate the estimated time t _min for the tram to reach the downstream adjacent intersection _(i) : Step 4. Obtain the clearing time t ₀ and the safety reserve time t ₁ of the downstream intersection according to the geometric type of the downstream adjacent intersection; Step 5. Based on the previous steps, calculate the estimated time t _min(i) for the tram to arrive at the downstream adjacent intersection, as well as the clearing time t ₀ and the safety reserved time t ₁ for the downstream adjacent intersection, and determine whether there is a risk of conflict: If the estimated time t _min(i) for the tram to arrive at the downstream adjacent intersection is greater than the sum t ₀ +t ₁ of the aforementioned downstream adjacent intersection clearing time t ₀ and safety reserved time t ₁ , it is determined that there is no risk, Return to the previous step 1; If the estimated time t _min(i) for the tram to arrive at the downstream adjacent intersection is less than or equal to the sum t ₀ +t ₁ of the aforementioned downstream adjacent intersection clearing time t ₀ and safety reserved time t ₁ , then it is determined that there is a risk , to issue an early warning signal. 2. the modern streetcar crossing signal control early warning method according to claim 1, is characterized in that, when judging at a certain sequence time t _i , if the estimated time t _{min ( i)} , less than or equal to the sum of t ₀ +t ₁ of the aforementioned downstream adjacent intersection clearance time t ₀ and safety reserved time t ₁ , it is determined that there is a traffic conflict between the tram and the downstream adjacent intersection, and the downstream adjacent intersection The controls emit audible and/or optical signals, which are fed back via displays and/or loudspeakers installed next to the intersection. 3. The modern tramway intersection signal control early warning method according to claim 2, characterized in that, when it is judged that there is a traffic conflict between the tramway and the downstream adjacent intersection, the control compulsorily converts the downstream adjacent intersection signal, and the downstream adjacent intersection signal The intersection enters the state of clearing the road with a yellow light, prohibiting vehicles outside the intersection from entering the intersection, and notifying vehicles that have passed the stop line of the intersection to leave the intersection as soon as possible through broadcasting; Telescopic fencing to physically isolate downstream adjacent intersections. 4. The modern tramway intersection signal control early warning method according to claim 1, characterized in that, in the aforementioned method, when it is determined that there is a traffic conflict between the tramway and the downstream adjacent intersection at a certain sequence time t _i , also through a network, to send early warning signals to the remote. 5. A modern streetcar crossing signal control early warning system is characterized in that the early warning system comprises: The modern tram operation information collection device 10 includes an RFID reader 12 for monitoring the RFID electronic tags installed at the front and rear positions of the tram, wherein: the RFID electronic tag stores the tram number information, and the aforementioned RFID reader The writer 12 is installed in a fixed position next to the tram track; one or more processors 20 for controlling the operation of the early warning system; At least one memory 60 for storing data and program instructions used by the one or more processors 20 configured to execute the program instructions for: Control described modern tram operation information collection device 10 to update tram operation information based on the RFID reader 12 installed in a fixed position; and based on the collected data, perform the following processing: a) Based on the time t _i1 of the collected tram head RFID electronic tag passing through the RFID reader, the time t _i2 of the tram tail RFID electronic tag passing through the RFID reader, and the length information Sq of the tram body, calculate The average speed information v _i of the tram from time t _i to time t _i2 : b) Calculate the estimated time t _{min ( i )} : c) Obtain the clearing time t ₀ and the safety reservation time t ₁ of the downstream intersection according to the geometric type of the downstream adjacent intersection; d) Based on the estimated time t _min(i) of the arrival of the tram at the downstream adjacent intersection, as well as the clearing time t ₀ and the safety reserved time t ₁ at the downstream adjacent intersection, determine whether there is a risk of conflict: If the estimated time t _min(i) for the tram to arrive at the downstream adjacent intersection is greater than the sum t ₀ +t ₁ of the aforementioned downstream adjacent intersection clearing time t ₀ and safety reserved time t ₁ , it is determined that there is no risk; If the estimated time t _min(i) for the tram to arrive at the downstream adjacent intersection is less than or equal to the sum t ₀ +t ₁ of the aforementioned downstream adjacent intersection clearing time t ₀ and safety reserved time t ₁ , then it is determined that there is a risk , to issue an early warning signal. 6. the modern streetcar intersection signal control early warning system according to claim 5, is characterized in that, described modern streetcar operation information collection device (10), comprises at least one RFID reader (12), fixed Installed within a range of 1 meter beside the track of the tram, the running data of the tram is collected, including the current position information of the tram and the time information passing through the at least one RFID reader (12). 7. The modern streetcar crossing signal control early warning system according to claim 4, characterized in that, the early warning system also includes a loudspeaker (30) and/or optical feedback device (31), connected to said one or Multiple processors (20). 8. The modern streetcar crossing signal control early warning system according to claim 4, characterized in that, the early warning system also includes a wireless communication device (40), connected to the one or more processors (20) . 9. The modern streetcar crossing signal control early warning system according to claim 4, characterized in that, the early warning system also includes a traffic signal device (50), connected to the one or more processors (20 ).