An information synchronization system for multimedia communication in urban rail transit

Abstract

The present invention discloses a multimedia communication information synchronization system for urban rail transit, which relates to the technical field of rail transit information processing, and includes a carrier marking unit, a mode switching unit, a synchronization management unit, a high-frequency display unit, a low-frequency display unit, and a synchronization compensation unit; according to the train schedule time within the urban rail transit station, the present invention marks the rail operation cycle, divides the working mode according to the passenger flow information of the rail transit station, automatically switches the working mode as the rail operation cycle changes, and selects different information source carriers according to the change of the working mode. The synchronization management unit is used to determine the transmission duration of each information source carrier, and then determine the sending timestamp of the signal acquisition request. At the same time, it receives the multimedia feedback information obtained from the information source carrier, determines that the feedback is complete, and determines the integrity of the multimedia feedback information according to the information request data packet. After generating an approval signal, it is displayed through the multimedia system.

Description

Technical Field

[0001] The present invention relates to the technical field of rail transit information processing, and in particular to an urban rail transit multimedia communication information synchronization system. Background Art

[0002] With the development of society, urban rail transit is not only a means of transportation, but also a carrier of urban culture. Combining the objective laws of the development of cultural industries in major cities and regional cultural characteristics, the urban rail value-added service development requirements are given unique cultural characteristics to play a benchmark role in urban cultural communication.

[0003] The passenger flow of rail transit is 2 million to 8 million people per day, and the passenger flow in densely populated cities is even greater. Passengers must stay for a while while waiting for the train, with an average stay time of 2 to 15 minutes. Multimedia systems will play an important role in transmitting information and promoting culture for rail transit platforms with large passenger flow. In order to utilize the blank and idle resources of the rail transit platform top box, and the platform top box is also the best viewing position for passengers to watch multimedia information, it is necessary to develop a multimedia system for the rail transit platform top box. The intelligent multimedia system adopts integrated control of the door control unit based on drive, logic control technology and media information transmission and the central controller based on programmable logic controller, and adopts service-oriented architecture to realize the processing and release of passenger information and provide multi-channel timely information release. The intelligent multimedia system uses the operation monitoring system software to realize real-time monitoring and control of the door control unit and the central control unit, and adopts the electromagnetic compatibility of the safety door control system and the media control center to generate conductive medium signals to isolate each other.

[0004] Existing methods for synchronous reproduction of multimedia information: When storing, replaying, retrieving and querying a collection of multimedia information including sound, image, text, whereabouts and behavior, the following technologies are currently used for integration:

[0005] 1. Collect and record sound and images through audio and video acquisition and recording systems;

[0006] 2. Record non-sound and non-image information through a computer database system;

[0007] 3. When tracing the source of multimedia information, non-sound and image information is played back or restored using the corresponding sound and image players, and non-sound and image information is searched, queried and displayed through the database query system. The instantaneous position of the monitored object is simulated and restored by comprehensively applying the database query system and virtual technology.

[0008] However, when tracing the process information, multiple systems that do not have a one-to-one correspondence in terms of time issues need to be used simultaneously. Therefore, neither in theory nor in practice can the synchronization problem of information such as sound, images, pictures, etc. and other multiple types of information such as non-sound, non-image, non-picture information during playback be solved.

[0009] In view of the above technical deficiencies, a solution is proposed. Summary of the Invention

[0010] The object of the present invention is to divide the working mode according to the passenger flow information of the rail transit station, automatically switch the working mode with the change of the rail operation cycle, select different information source carriers according to the change of the working mode, use the synchronization management unit to determine the transmission duration of each information source carrier, and then determine the transmission timestamp of the signal acquisition request. At the same time, receive the multimedia feedback information obtained from the information source carrier, determine that the feedback is complete, and determine the integrity of the multimedia feedback information according to the information request data packet. After generating the approval signal, it is displayed through the multimedia system.

[0011] To achieve the above object, the present invention adopts the following technical solution: An urban rail transit multimedia communication information synchronization system, including a carrier marking unit, a mode switching unit, a synchronization management unit, a high-frequency display unit, a low-frequency display unit, and a synchronization compensation unit;

[0012] The carrier marking unit targets the information source carriers involved in the urban rail transit multimedia information system, marks each information source carrier as N, and further marks the in-station train number information source carrier as N1 and the cultural display information source carrier as N2;

[0013] The mode switching unit is used to mark the rail operation cycle according to the train schedule time in the urban rail transit station, divide the working mode according to the passenger flow information of the rail transit station, and automatically generate a mode switching signal according to the change of the working mode with the rail operation cycle and send it to the high-frequency display unit or the low-frequency display unit, where the working mode includes a high-frequency traffic mode, a normal traffic mode, and a low-frequency mode;

[0014] The high-frequency display unit is used to select the in-station train number information source carrier N1 and the cultural display information source carrier N2 in the high-frequency traffic mode according to the multimedia information requirements in the urban rail transit station, and send an information request data packet to the corresponding information source carrier after receiving the mode switching signal;

[0015] The low-frequency display unit is used to select the in-station train number information source carrier N1 and the cultural display information source carrier N2 in the low-frequency traffic mode according to the multimedia information requirements in the urban rail transit station, and send an information request data packet to the corresponding information source carrier after receiving the mode switching signal;

[0016] The synchronization management unit is used to determine the transmission duration with each information source carrier, and then determine the transmission timestamp of the signal acquisition request. At the same time, it receives the multimedia feedback information obtained from the information source carrier and sends it to the high-frequency display unit or the low-frequency display unit;

[0017] The synchronization compensation unit is used to pre-store the received multimedia feedback information, determine that the feedback is complete, and determine the integrity of the multimedia feedback information according to the information request data packet, and generate an approval signal and a feedback compensation signal to the synchronization management unit.

[0018] Further, the information source carriers include audio information sources, video information sources, text information sources, and picture information sources. Among them, the number of text information sources in N1 is the largest, and the number of video information sources in N2 is the largest.

[0019] Further, the mode switching unit includes a mode division module and a time period switching module. The mode division module obtains the train schedule time in the urban rail transit station, marks the total running duration of the train within a working day as the rail operation cycle, and divides an rail operation cycle into a high-frequency traffic cycle, a normal traffic cycle, and a low-frequency traffic cycle according to the passenger flow information of the rail transit station, that is, correspondingly generates a high-frequency traffic mode, a normal traffic mode, and a low-frequency mode;

[0020] The time period switching module is used for timing, and correspondingly generates a mode switching signal at the cycle nodes of the high-frequency traffic cycle, the normal traffic cycle, and the low-frequency traffic cycle and sends it to the synchronization management unit.

[0021] Further, the synchronization management unit includes a channel establishment module and a demand response module. The channel establishment module is used to establish an information transmission channel with the information source carrier and perform encryption protection. After establishing the encrypted information channel, it sends an analog demand signal to each information source carrier, obtains the transmission duration of the analog demand signal sent to each information source carrier, and then determines the information feedback duration;

[0022] The specific process of determining the information feedback duration is as follows:

[0023] Step 1: Obtain the transmission duration tn of the analog demand signal sent to each information source carrier to obtain a signal delivery duration set A: A = {t1, t2, t3,..., tn}, where n is the number of information source carriers, arrange the elements in the set A in descending order of duration value, and mark the first tn in the sorting as the delay delivery duration ti;

[0024] Step 2: Obtain the transmission duration \(t_n'\) of each information source carrier to feedback information to the synchronization management unit, and obtain the signal reception duration set B: B = {t1', t2', t3', …, t_n'}, arrange the elements in set B in descending order of duration value, and mark the t_n' with the first sorting as the delayed reception duration \(t_i'\);

[0025] Step 3: According to the information source carriers corresponding to the elements in the signal transmission duration set A and the signal feedback reception set B, the information feedback duration \(t_m = t_n + t_n'\) of each information source carrier can be determined;

[0026] Step 4: Mark the sum of the delayed transmission duration \(t_i\) and the delayed reception duration \(t_i'\) as the time stamp limit value, which is used to judge the validity of the sent time stamp. The time stamp greater than the time stamp limit value is an invalid time stamp;

[0027] The demand response module determines the transmission time stamp for sending the information request data packet to each information source carrier based on the information feedback duration, sends the information acquisition request to the corresponding information source carrier according to the transmission time stamp after receiving the information demand signal, and sends the received multimedia feedback information to the high-frequency display unit or the low-frequency display unit.

[0028] Further, the specific process of delimiting the working mode is as follows:

[0029] S101: According to the train schedule time in the urban rail transit station, calculate the track operation cycle duration with the departure time of the first train as the starting time and the arrival time of the last train as the end time;

[0030] S102: During the track operation cycle, obtain the passenger flow information of the rail transit station in real time. The passenger flow information includes the total passenger flow \(M_k\) and the flow frequency \(F_k\), and calculate the passenger flow frequency coefficient according to the passenger flow information: where \(e_1\) and \(e_2\) are preset proportionality coefficients, and \(U_k\) is the passenger flow frequency coefficient;

[0031] S103: Preset the passenger flow frequency interval (\(U_{min}\), \(U_{max}\)). If the passenger flow frequency coefficient is less than or equal to \(U_{min}\), then this moment is delimited as a low-frequency moment;

[0032] If the passenger flow frequency coefficient is greater than \(U_{min}\) and less than \(U_{max}\), then this moment is delimited as a normal moment;

[0033] If the passenger flow frequency coefficient is greater than or equal to \(U_{max}\), then this moment is delimited as a high-frequency moment;

[0034] S104. Obtain all low-frequency moments and integrate them into time dataset A, all low-frequency moments into time dataset B, and all low-frequency moments into time dataset C. Integrate the concentrated time periods within each time dataset respectively to obtain the high-frequency traffic cycle, the normal traffic cycle, and the low-frequency traffic cycle.

[0035] Further, the process of sending the information request data packet is as follows:

[0036] S201. Take the acquisition mode switching signal as the judgment time point. According to the timing module, obtain whether the judgment time point is in the high-frequency traffic cycle, the normal traffic cycle, or the low-frequency traffic cycle, and perform mode switching according to the judgment result.

[0037] When entering the high-frequency traffic mode, based on the principle that the train number information occupies the main part of the multimedia system display panel, select the in-station train number information source carrier N1 and the cultural display information source carrier N2 in the high-frequency traffic mode.

[0038] When entering the normal traffic mode, select the in-station train number information source carrier N1 and the cultural display information source carrier N2 in the normal traffic mode according to the cultural carrier intention principle of urban rail transit.

[0039] When entering the low-frequency mode, based on the principle that the cultural display occupies the main part of the multimedia system display panel, select the in-station train number information source carrier N1 and the cultural display information source carrier N2 in the low-frequency traffic mode.

[0040] S203. According to the working mode at the judgment time point, obtain the in-station train number information source carrier N1 and the cultural display information source carrier N2, and generate an information request data packet with a pointing mark.

[0041] Further, the specific process of determining the integrity of the multimedia feedback information is as follows:

[0042] S301. Obtain the information request data packet. The information request data includes an information request signal and a request target label, specifically the in-station train number information source carrier N1 and the cultural display information source carrier N2.

[0043] S302. Obtain the pre-stored multimedia feedback information. Determine its information source carrier according to the multimedia feedback information, and compare the label corresponding to the information source carrier with the request target label.

[0044] S303. According to the marked comparison result, if the labels are all consistent after comparison, generate an approval signal and send it to the synchronization management unit.

[0045] If there is a deviation after the label comparison, generate a feedback compensation and send it to the synchronization management unit.

[0046] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are as follows:

[0047] The present invention marks the track operation cycle according to the train schedule time within the urban rail transit station, divides the working mode according to the passenger flow information of the rail transit station, automatically switches the working mode as the track operation cycle changes, selects different information source carriers according to the change of the working mode, determines the transmission duration of each information source carrier through the synchronization management unit, and then determines the sending timestamp of the signal acquisition request. At the same time, it receives the multimedia feedback information obtained from the information source carrier, determines that the feedback is complete, and determines the integrity of the multimedia feedback information according to the information request data packet. After generating the approval signal, it is displayed through the multimedia system. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 The overall structural schematic diagram of the present invention is shown. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0049] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0050] Embodiment 1:

[0051] As Figure 1 shown, an urban rail transit multimedia communication information synchronization system includes a carrier marking unit, a mode switching unit, a synchronization management unit, a high-frequency display unit, a low-frequency display unit, and a synchronization compensation unit;

[0052] The carrier marking unit targets the information source carriers involved in the urban rail transit multimedia information system, marks each information source carrier as N, and further marks the in-station train information source carrier as N1 and the cultural display information source carrier as N2;

[0053] Among them, the information source carriers include audio information sources, video information sources, text information sources, and picture information sources. Among them, the number of text information sources in N1 is the largest, and the number of video information sources in N2 is the largest.

[0054] The mode switching unit is used to mark the track operation cycle according to the train schedule time in the urban rail transit station, divide the working mode according to the passenger flow information of the rail transit station, and automatically generate a mode switching signal according to the change of the working mode with the track operation cycle and send it to the high-frequency display unit or the low-frequency display unit, where the working modes include the high-frequency flow mode, the normal flow mode, and the low-frequency mode;

[0055] The mode switching unit includes a mode division module and a time period switching module. The mode division module obtains the train schedule time in the urban rail transit station, marks the total running duration of the trains within a working day as the track operation cycle, and divides an orbit operation cycle into a high-frequency flow cycle, a normal flow cycle, and a low-frequency flow cycle according to the passenger flow information of the rail transit station, that is, correspondingly generates the high-frequency flow mode, the normal flow mode, and the low-frequency mode;

[0056] The specific process of defining the working mode is as follows:

[0057] S101. According to the train schedule time in the urban rail transit station, taking the departure time of the first train as the starting time and the arrival time of the last train as the end time, calculate the duration of the track operation cycle;

[0058] S102. During the track operation cycle, obtain the passenger flow information of the rail transit station in real time. The passenger flow information includes the total number of passengers Mk and the flow frequency Fk, and calculate the flow frequency coefficient according to the passenger flow information: where e1 and e2 are preset proportionality coefficients, and Uk is the flow frequency coefficient;

[0059] S103. Preset the flow frequency interval (Umin, Umax). If the flow frequency coefficient is less than or equal to Umin, it is defined that this moment is a low-frequency moment;

[0060] If the flow frequency coefficient is greater than Umin and less than Umax, it is defined that this moment is a normal moment;

[0061] If the flow frequency coefficient is greater than or equal to Umax, it is defined that this moment is a high-frequency moment;

[0062] S104. Obtain all the low-frequency moments and integrate them into the time data set A, all the normal moments and integrate them into the time data set B, and all the high-frequency moments and integrate them into the time data set C. Then, integrate the concentrated time periods within each time data set to obtain the high-frequency flow cycle, the normal flow cycle, and the low-frequency flow cycle.

[0063] The time period switching module is used for timing, and correspondingly generates a mode switching signal at the cycle nodes of the high-frequency flow cycle, the normal flow cycle, and the low-frequency flow cycle and sends it to the synchronization management unit.

[0064] The high-frequency display unit is used to select the in-station train number information source carrier N1 and the cultural display information source carrier N2 in the high-frequency traffic mode according to the multimedia information requirements in the urban rail transit station, and send an information request data packet to the corresponding information source carrier after receiving the mode switching signal;

[0065] The low-frequency display unit is used to select the in-station train number information source carrier N1 and the cultural display information source carrier N2 in the low-frequency traffic mode according to the multimedia information requirements in the urban rail transit station, and send an information request data packet to the corresponding information source carrier after receiving the mode switching signal;

[0066] The synchronization management unit is used to determine the transmission duration with each information source carrier, and then determine the transmission timestamp of the signal acquisition request. At the same time, it receives the multimedia feedback information obtained from the information source carrier and sends it to the high-frequency display unit or the low-frequency display unit;

[0067] The process of sending the information request data packet is as follows:

[0068] S201. Taking the acquisition of the mode switching signal as the judgment time point, according to the timing module, obtain whether the judgment time point is in the high-frequency traffic cycle, the normal traffic cycle or the low-frequency traffic cycle, and perform mode switching according to the judgment result;

[0069] When entering the high-frequency traffic mode, based on the principle that the train number information occupies the main part of the multimedia system display panel, select the in-station train number information source carrier N1 and the cultural display information source carrier N2 in the high-frequency traffic mode;

[0070] When entering the normal traffic mode, select the in-station train number information source carrier N1 and the cultural display information source carrier N2 in the normal traffic mode according to the cultural carrier intention principle of the urban rail transit;

[0071] When entering the low-frequency mode, based on the principle that the cultural display occupies the main part of the multimedia system display panel, select the in-station train number information source carrier N1 and the cultural display information source carrier N2 in the low-frequency traffic mode;

[0072] S203. According to the working mode at the judgment time point, obtain the in-station train number information source carrier N1 and the cultural display information source carrier N2, and generate an information request data packet with a pointing mark.

[0073] The synchronization management unit includes a channel establishment module and a demand response module. The channel establishment module is used to establish an information transmission channel with the information source carrier and perform encryption protection. After establishing the encrypted information channel, send an analog demand signal to each information source carrier, obtain the transmission duration of the analog demand signal sent to each information source carrier, and then determine the information feedback duration;

[0074] The specific process of determining the information feedback duration is as follows:

[0075] Step 1: Obtain the transmission duration tn of the simulated demand signal sent to each information source carrier, and obtain the signal transmission duration set A: A = {t1, t2, t3,..., tn}, where n is the number of information source carriers. Arrange the elements in set A in descending order of duration value, and mark the first tn in the sorting as the delayed transmission duration ti;

[0076] Step 2: Obtain the transmission duration tn' of each information source carrier to feedback information to the synchronization management unit, and obtain the signal reception duration set B: B = {t1', t2', t3',..., tn'}. Arrange the elements in set B in descending order of duration value, and mark the first tn' in the sorting as the delayed reception duration ti';

[0077] Step 3: According to the information source carriers corresponding to the elements in the signal transmission duration set A and the signal feedback reception set B, the information feedback duration tm of each information source carrier can be determined as tm = tn + tn';

[0078] Step 4: Mark the sum of the time of the delayed transmission duration ti and the delayed reception duration ti' as the time stamp limit value, which is used to judge the validity of the sent time stamp. The time stamp greater than the time stamp limit value is an invalid time stamp;

[0079] The demand response module determines the send time stamp for sending the information request data packet to each information source carrier based on the information feedback duration. After receiving the information demand signal, it sends an information acquisition request to the corresponding information source carrier according to the send time stamp, and sends the received multimedia feedback information to the high-frequency display unit or the low-frequency display unit.

[0080] The synchronization compensation unit is used to pre-store the received multimedia feedback information, determine that the feedback is complete, and determine the integrity of the multimedia feedback information according to the information request data packet, and generate an approval signal and a feedback compensation signal to the synchronization management unit.

[0081] The specific process of determining the integrity of the multimedia feedback information is as follows:

[0082] S301: Obtain the information request data packet, and the information request data includes an information request signal and a request target label, specifically the in-station train number information source carrier N1 and the cultural display information source carrier N2;

[0083] S302: Obtain the pre-stored multimedia feedback information, determine its information source carrier according to the multimedia feedback information, and compare the label corresponding to the information source carrier with the request target label;

[0084] S303. According to the marked comparison result, if all the label comparisons are consistent, an approval signal is generated and sent to the synchronization management unit;

[0085] If there is a deviation after the label comparison, a feedback compensation is generated and sent to the synchronization management unit.

[0086] The present invention marks the track operation cycle according to the train schedule time in the urban rail transit station, divides the working mode according to the passenger flow information of the rail transit station, automatically switches the working mode as the track operation cycle changes, selects different information source carriers according to the change of the working mode, uses the synchronization management unit to determine the transmission duration of each information source carrier, and then determines the sending timestamp of the signal acquisition request. At the same time, it receives the multimedia feedback information obtained from the information source carrier, determines that the feedback is complete, and determines the integrity of the multimedia feedback information according to the information request data packet. After generating an approval signal, it is displayed through the multimedia system.

[0087] The setting of the interval and the threshold value is for the convenience of comparison. Regarding the size of the threshold value, it depends on the amount of sample data and the base quantity set by those skilled in the art for each group of sample data; as long as it does not affect the proportional relationship between the parameters and the quantified values.

[0088] The above formulas are all dimensionless and take their numerical calculations. The formula is obtained by collecting a large amount of data and performing software simulation to get a formula closest to the actual situation. The preset parameters in the formula are set by those skilled in the art according to the actual situation;

[0089] In the embodiments provided in the present application, it should be understood that the disclosed system can be implemented in other ways; for example, the division of the modules is only a logical function division, and there can be other division methods in actual implementation. For example, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed; another point, the displayed or discussed coupling or direct coupling or communication connection to each other can be through some interfaces, and the indirect coupling or communication connection of the device or module can be in electrical, mechanical or other forms;

[0090] The above is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. An urban rail transit multimedia communication information synchronization system, characterized in that: It includes a carrier marking unit, a mode switching unit, a synchronization management unit, a high-frequency display unit, a low-frequency display unit and a synchronization compensation unit; The carrier marking unit targets the information source carriers involved in the urban rail transit multimedia information system, marks each information source carrier as N, and then marks the source carrier of the train information in the station as N1, and marks the source carrier of the cultural display information as N2; The mode switching unit is used to mark the rail operation cycle according to the train schedule time in the urban rail transit station, and divide the working mode according to the passenger flow information of the rail transit station, and automatically generate a mode switching signal according to the change of the working mode with the rail operation cycle and send it to the high-frequency display unit or the low-frequency display unit, wherein the working mode includes a high-frequency flow mode, a normal flow mode and a low-frequency mode; The high-frequency display unit is used to select the station train information source carrier N1 and the cultural display information source carrier N2 under the high-frequency flow mode according to the multimedia information demand in the urban rail transit station, and send an information request data packet to the corresponding information source carrier after receiving the mode switching signal; The low-frequency display unit is used to select the station train information source carrier N1 and the cultural display information source carrier N2 in the low-frequency flow mode according to the multimedia information demand in the urban rail transit station, and send an information request data packet to the corresponding information source carrier after receiving the mode switching signal; The synchronization management unit is used to determine the transmission time with each information source carrier, thereby determining the sending timestamp of the signal acquisition request, and at the same time, the multimedia feedback information received from the information source carrier is sent to the high-frequency display unit or the low-frequency display unit; The synchronization compensation unit is used to pre-store the received multimedia feedback information, determine the integrity of the multimedia feedback information according to the information request data packet after determining the feedback is complete, and generate an approval signal and a feedback compensation signal to the synchronization management unit; The synchronization management unit includes a channel establishment module and a demand response module. The channel establishment module is used to establish an encrypted information transmission channel with the information source carrier, and obtain the signal transmission time (tn) and reception time (tn') of each information source carrier by sending a simulated demand signal to calculate the information feedback time (tm=tn+tn'); The demand response module determines a sending timestamp of a signal acquisition request based on the information feedback duration (tm), sends an information acquisition request to the information source carrier according to the sending timestamp, and transmits the received multimedia feedback information to the high-frequency or low-frequency display unit; The synchronous compensation unit is used to pre-store multimedia feedback information, and generate an approval signal or a feedback compensation signal after determining the integrity by comparing the target label in the information request data packet with the feedback information label.

2. The urban rail transit multimedia communication information synchronization system according to claim 1, characterized in that: The information source carriers include audio information sources, video information sources, text information sources, and picture information sources. Among them, N1 has the largest number of text information sources, and N2 has the largest number of video information sources.

3. The urban rail transit multimedia communication information synchronization system according to claim 1, characterized in that: The mode switching unit includes a mode division module and a time period switching module. The mode division module obtains the train scheduling time in the urban rail transit station, marks the total running time of the train in a working day as the rail operation cycle, and divides a rail operation cycle into a high-frequency flow cycle, a normal flow cycle and a low-frequency flow cycle according to the passenger flow information of the rail transit station, that is, generates a high-frequency flow mode, a normal flow mode and a low-frequency mode accordingly; The time period switching module is used for timing, and generates a mode switching signal corresponding to the period nodes of the high-frequency traffic period, the normal traffic period and the low-frequency traffic period to the synchronization management unit.

4. The urban rail transit multimedia communication information synchronization system according to claim 1, characterized in that: The synchronization management unit includes a channel establishment module and a demand response module, wherein the channel establishment module is used to establish an information transmission channel with the information source carrier and perform encryption protection. After the encrypted information channel is established, a simulated demand signal is sent to each information source carrier to obtain the transmission time of the simulated demand signal to each information source carrier, and then determine the information feedback time; The specific process of determining the information feedback duration is as follows: Step 1: obtain the transmission time tn of the simulated demand signal sent to each information source carrier, and obtain the signal transmission time set A: A = {t1, t2, t3, ..., tn}, where n is the number of information source carriers, and arrange the elements in the set A in descending order according to the time value, and mark the first tn as the delayed transmission time ti; Step 2: Obtain the transmission duration tn′ of each information source carrier to feed back information to the synchronization management unit, and obtain a signal reception duration set B: B = {t1′, t2′, t3′, …, tn′}, and arrange the elements in the set B in descending order according to the duration value, and mark the first tn′ as the delayed reception duration ti′; Step 3: According to the information source carriers corresponding to the elements in the signal transmission duration set A and the signal feedback reception set B, the information feedback duration tm=tn+tn′ of each information source carrier can be determined; Step 4: mark the sum of the delayed transmission time ti and the delayed reception time ti′ as the timestamp limit value, which is used to determine the validity of the sending timestamp. A timestamp greater than the timestamp limit value is an invalid timestamp. The demand response module determines the sending timestamp of sending the information request data packet to each of the information source carriers based on the information feedback duration, sends an information acquisition request to the corresponding information source carrier according to the sending timestamp after receiving the information demand signal, and sends the received multimedia feedback information to the high-frequency display unit or the low-frequency display unit.

5. The urban rail transit multimedia communication information synchronization system according to claim 1, characterized in that: The specific process of defining the working mode is as follows: S101. According to the train schedule at the urban rail transit station, the departure time of the first train is used as the starting time, and the arrival time of the last train is used as the end time, to calculate the rail operation cycle duration; S102. During the rail operation cycle, the passenger flow information of the rail transit station is obtained in real time. The passenger flow information includes the total passenger flow Mk and the flow frequency Fk. The passenger flow frequency coefficient is calculated based on the passenger flow information: Among them, e1 and e2 are preset proportional coefficients, and Uk is the flow frequency coefficient; S103, preset a crowd frequency interval (Umin, Umax), if the crowd frequency coefficient is less than or equal to Umin, then the moment is defined as a low frequency moment; If the passenger flow frequency coefficient is greater than Umin and less than Umax, the moment is defined as a normal moment; If the passenger flow frequency coefficient is greater than or equal to Umax, the moment is defined as a high-frequency moment; S104. Obtain all low-frequency moments and integrate them into time data set A, integrate all low-frequency moments into time data set B, and integrate all low-frequency moments into time data set C. Integrate the concentrated time periods in each time data set to obtain high-frequency traffic cycles, normal traffic cycles, and low-frequency traffic cycles.

6. The urban rail transit multimedia communication information synchronization system according to claim 1, characterized in that: The process of sending an information request packet is as follows: S201, obtaining a mode switching signal as a judgment time point, obtaining, according to a timing module, whether the judgment time point is a high-frequency flow period, a normal flow period, or a low-frequency flow period, and performing mode switching according to the judgment result; S202, when entering the high-frequency traffic mode, based on the principle that the train information occupies the main part of the multimedia system display panel, the source carrier N1 of the train information in the station and the source carrier N2 of the cultural display information in the high-frequency traffic mode are selected; When entering the normal flow mode, according to the cultural carrier intention principle of urban rail transit, the source carrier N1 of the station train information and the source carrier N2 of the cultural display information under the normal flow mode are selected; When entering the low-frequency mode, based on the principle that cultural display occupies the main part of the multimedia system display panel, the source carrier N1 of the train information in the station under the low-frequency flow mode and the source carrier N2 of the cultural display information are selected; S203. According to the working mode at the determined time point, the source carrier N1 of the train information in the station and the source carrier N2 of the cultural display information are obtained, and an information request data packet with a pointing mark is generated.

7. The urban rail transit multimedia communication information synchronization system according to claim 1, characterized in that: The specific process of determining the integrity of multimedia feedback information is as follows: S301, obtaining an information request data packet, the information request data including an information request signal and a request target number, specifically, a source carrier N1 of the train number information within the station and a source carrier N2 of the cultural display information; S302, obtaining pre-stored multimedia feedback information, determining its information source carrier according to the multimedia feedback information, and comparing the label corresponding to the information source carrier with the request target label; S303, according to the red comparison result, if the numbers are consistent after comparison, an approval signal is generated and sent to the synchronization management unit; If there is a deviation after label comparison, feedback compensation is generated and sent to the synchronization management unit.

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