Train safety coupling control method based on Ethernet

Abstract

The present application relates to the technical field of train coupling, and specifically to a train safety coupling control method based on Ethernet, the method comprising: analyzing the correlation characteristics of the vehicle's resistance and the adjacent vehicle's speed based on the relationship between the vehicle's resistance and the adjacent vehicle's speed when communication is normal, and the probability distribution of the adjacent vehicle's speed; when communication is interrupted, calculating the adjacent vehicle's position and displacement probability according to the correlation characteristics of the vehicle's resistance and the adjacent vehicle's speed; calculating the collision safety factor according to the adjacent vehicle's position and displacement probability, constructing a robust safety control strategy according to the collision safety factor, completing the safety control of the train coupling, taking into account the speed error problem of the adjacent vehicle that may exist due to the environment, adopting feature extraction means to obtain the correlation characteristics of train data, estimating the speed error of the adjacent vehicle through the vehicle's operating data, and appropriately adjusting the vehicle's position, which can avoid the hidden danger of train collision caused by the control distance error due to communication interruption and reduce the risk of train collision.

Description

Technical Field

[0001] The present application relates to the technical field of train coupling, and in particular to a train safety coupling control method based on Ethernet. Background Art

[0002] Train coupling is a method to improve the efficiency of railway transportation by allowing multiple trains to be connected to form a longer train to increase the capacity of a single transport. Traditionally, train coupling is to connect vehicles together through physical connection devices, while modern virtual coupling technology exchanges information through wireless communication devices to achieve synchronous operation between trains without physical connection. Virtual coupling technology enables trains to run in a relatively static state, thereby achieving close parallel travel, which not only improves the utilization rate of railway lines, but also increases transportation flexibility.

[0003] There are two modes for train coupling schemes, namely moving block mode and coupling operation mode. When the train is in coupling operation mode, communication errors may occur due to unpredictable factors such as electromagnetic interference, and then due to errors in information exchange between vehicles, the train speed control errors may occur, affecting the stability and safety of the coupling. In response to such communication errors, the traditional method uses a safe buffer distance between the two trains to prevent train collisions. However, when the communication interruption time is too long, the control distance error between the trains is too large, and there is still a risk of train collision. Summary of the invention

[0004] In order to solve the above technical problems, the present application provides an Ethernet-based train safety coupling control method to solve the existing problems.

[0005] The Ethernet-based train safety coupling control method of the present application adopts the following technical solutions:

[0006] An embodiment of the present application provides a train safety coupling control method based on Ethernet, the method comprising the following steps:

[0007] The train to be controlled is recorded as the own train, and the train before the own train is recorded as the neighboring train; the speed of the neighboring train at each moment, the resistance of the own train at each moment, and the safety buffer distance under the coupling operation mode are collected;

[0008] Based on the numerical range of the vehicle's resistance, the resistance data is divided into discrete intervals, and the state labels of the speeds of neighboring vehicles are set based on the discrete intervals where the resistances of the vehicle are located; the probability density function of all speeds of the state labels of the neighboring vehicles is constructed;

[0009] Obtain a preset number of sub-intervals of each probability density function by dividing the intervals; calculate the speed occurrence probability of the speed of the neighboring vehicle in each sub-interval based on the probability density function in each sub-interval;

[0010] Based on the neighboring vehicle speeds of all the partitions of each state tag, a neighboring vehicle displacement sequence of resistance at each moment after communication interruption is constructed; based on all the neighboring vehicle displacement sequences, various neighboring vehicle displacements at the current moment are obtained; and combined with the speed occurrence probability, the displacement occurrence probability of various neighboring vehicle displacements at the current moment is calculated;

[0011] Based on the displacement of the vehicle at the current moment and the displacement of various neighboring vehicles at the current moment, various relative displacements between the neighboring vehicle and the vehicle at the current moment are obtained; based on the speed of the vehicle at the start of the communication interruption and the length of time to the current moment, the virtual position of the vehicle at the current moment is determined; based on the displacement occurrence probability of the neighboring vehicle displacement corresponding to various relative displacements, combined with the virtual position of the vehicle, the collision probability between the vehicle and the neighboring vehicle when the neighboring vehicle is at each preset position at the current moment is constructed; based on the collision probability and safety buffer distance at all preset positions, the collision safety factor of the vehicle at the current moment is determined;

[0012] Train safety coupling control is carried out based on the collision safety factor and safety buffer distance of the vehicle at the current moment.

[0013] In one embodiment, the process of dividing the discrete intervals is:

[0014] The number of preset discrete intervals is recorded as B; the maximum and minimum values ​​of the vehicle's resistance at all times are obtained; the difference between the maximum and minimum values ​​is recorded as D, and the discrete intervals are , ,……, , , where C is the minimum value.

[0015] In one embodiment, the method for setting the status labels of the speeds of the neighboring vehicles is as follows:

[0016] If any resistance of the vehicle is in the bth discrete interval, the speed of the neighboring vehicle at the same moment as any resistance of the vehicle is set as state label b.

[0017] In one embodiment, the process of obtaining the speed occurrence probability of the adjacent vehicle speed in each partition is as follows:

[0018] For each of the partitions of each state label, the speed of the midpoint of the partition is used as the neighboring vehicle speed of the partition, and the normalized value of the integral area of ​​the probability density function within the partition is used as the speed occurrence probability of the neighboring vehicle speed of the partition.

[0019] In one embodiment, the process of obtaining the displacement occurrence probability of each type of neighboring vehicle displacement at the current moment is as follows:

[0020] The product of each neighboring vehicle speed in the neighboring vehicle speed sequence of each state label and the sampling time interval is used as each displacement value; all the displacement values ​​of the neighboring vehicle speed sequence are combined into a sequence to obtain the neighboring vehicle displacement sequence of each state label;

[0021] For the resistance of the vehicle at each moment after the communication is interrupted, the displacement sequence of the neighboring vehicle corresponding to the state label of the discrete interval where the resistance of the vehicle is located is obtained as the displacement sequence of the neighboring vehicle of the resistance of the vehicle;

[0022] During the period from the beginning of the communication interruption to the current moment, a displacement value is taken from each displacement sequence of the neighboring vehicle of the vehicle's resistance at all moments to be combined to obtain various permutations and combinations; the sum of all displacement values ​​selected from various permutations and combinations is used as the current neighboring vehicle displacement of various permutations and combinations; the product of the speed occurrence probabilities of the neighboring vehicle speeds between the partitions corresponding to all displacement values ​​selected from various permutations and combinations is used as the combination occurrence probability of various permutations and combinations;

[0023] All permutations and combinations of neighboring vehicle displacements of the same magnitude are classified into one category to obtain various neighboring vehicle displacements at the current moment; the sum of the combined occurrence probabilities of all permutations and combinations of various neighboring vehicle displacements at the current moment is taken as the displacement occurrence probability of various neighboring vehicle displacements at the current moment.

[0024] In one embodiment, the relative displacements between the neighboring vehicle and the vehicle at the current moment are:

[0025] The displacement of the vehicle from the beginning of the communication interruption to the current moment is obtained, which is recorded as the displacement of the vehicle at the current moment; the difference between the displacement of each type of neighboring vehicle at the current moment and the displacement of the vehicle at the current moment is taken as the relative displacement between the neighboring vehicle and the vehicle at the current moment.

[0026] In one embodiment, the virtual position of the vehicle at the current moment is:

[0027] The position of the vehicle at the beginning of communication interruption is recorded as ; The vehicle's speed at the beginning of the communication interruption is recorded as ; The time from the communication interruption to the current time is recorded as ; The virtual position of the vehicle at the current moment The calculation method is: .

[0028] In one embodiment, the process of obtaining the collision probability between the vehicle and the neighboring vehicle when the neighboring vehicle is at each preset position at the current moment is as follows:

[0029] Assume that the neighboring car is at coordinate point x at the current moment, and obtain the distance between coordinate point x and the virtual position of the current car, which is recorded as ; Among all the relative displacements of the classes, obtain the relative displacement value less than The relative displacement of the neighboring car is taken as the collision-probable relative displacement when the neighboring car is at coordinate point x; the sum of the displacement occurrence probabilities of all the collision-probable relative displacements is taken as the collision probability between the vehicle and the neighboring car when the neighboring car is at coordinate point x.

[0030] In one embodiment, the process of obtaining the collision safety factor of the vehicle at the current moment is:

[0031] The safety buffer distance between the vehicle and the neighboring vehicle is recorded as , the maximum and minimum values ​​of all types of relative displacements between the neighboring vehicle and the vehicle at the current moment are recorded as and , the value range As the location area of ​​the neighboring vehicle at the current moment, is the virtual position of the vehicle at the current moment;

[0032] The collision safety factor of the vehicle at the current moment is recorded as , The expression is: , where X is the number of coordinate points selected in the neighboring vehicle position area at the current moment, is the collision probability when the neighboring vehicle is at the z-th coordinate point in the position area at the current moment, It is the distance between the virtual position of the vehicle at the current moment and the zth coordinate point in the position area.

[0033] In one embodiment, the train safety coupling control based on the collision safety factor and safety buffer distance of the vehicle at the current moment is specifically as follows:

[0034] In the case of communication interruption, if the collision safety factor of the vehicle at the current moment is less than the safety buffer distance, the speed of the vehicle is controlled and adjusted so that the vehicle is in a position where the collision safety factor is greater than the safety buffer distance; otherwise, the speed of the vehicle is not adjusted.

[0035] This application has at least the following beneficial effects:

[0036] Trains exchange information with each other to conduct virtual coupling, record each train as the own train, and record the previous train of each train as the neighboring train; based on the relationship between the resistance of the own train and the speed of the neighboring train when communication is normal, and the probability distribution of the speed of the neighboring train, the speed sequence of the neighboring train corresponding to the state label of each resistance of the own train is constructed, and the correlation characteristics between the resistance of the own train and the speed of the neighboring train are analyzed, so as to achieve the effect of estimating the speed of the neighboring train based on the resistance of the own train; when communication is interrupted, the probability of the position and displacement of the neighboring train is calculated according to the correlation characteristics of the resistance of the own train and the speed of the neighboring train, and the neighboring train may appear in different positions due to speed fluctuations, as well as the probability of displacement at each position; the collision safety factor is calculated according to the probability of the position and displacement of the neighboring train, and the risk of collision between the own train and the neighboring train is characterized; finally, according to the collision safety factor, a robust safety control strategy is constructed to complete the safety control of train coupling, taking into account the speed error problem of the neighboring train due to the environment, and using feature extraction to obtain the correlation characteristics of the train data. The speed error of the neighboring train is estimated through the running data of the own train, and the position of the own train is appropriately adjusted, which can avoid the hidden danger of train collision caused by the control distance error due to communication interruption and reduce the risk of train collision. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0038] Figure 1 A flow chart of the Ethernet-based train safety coupling control method provided in this application;

[0039] Figure 2 Schematic diagram of the process of obtaining the displacement probability of the neighboring vehicle at the current moment. DETAILED DESCRIPTION

[0040] In order to further explain the technical means and effects adopted by the present application to achieve the predetermined invention purpose, the specific implementation method, structure, features and effects of the Ethernet-based train safety coupling control method proposed by the present application are described in detail below in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0041] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0042] The specific scheme of the Ethernet-based train safety coupling control method provided by the present application is described in detail below with reference to the accompanying drawings.

[0043] An embodiment of the present application provides an Ethernet-based train safety coupling control method.

[0044] Specifically, the following Ethernet-based train safety coupling control method is provided, please refer to Figure 1 , the method comprises the following steps:

[0045] Step S1, record the train to be controlled as the own train, and record the train before the own train as the adjacent train; collect the speed of the adjacent train at each moment, the resistance of the own train at each moment, and the safety buffer distance in the coupling operation mode.

[0046] The first train is in front of the second train, and the second train is recorded as the train itself, and the first train is recorded as the neighboring train. When the train is in the coupling operation mode, for the second train, the periodic information received in real time from the first train is obtained, including the speed of the first train at each time. Preferably, in one embodiment of the present application, for the collection of the speed of the first train, the sampling time interval of the speed of the first train is set to 100 milliseconds, and the sampling duration is set to 10 minutes before the current time. As other embodiments of the present application, the implementer can set the data collection time period and sampling time interval according to the actual situation. The communication information is completed by the Ethernet constructed between the trains.

[0047] Among them, if the coupling time between the first train and the second train is less than ten minutes, the historical data of the coupling of the two trains in the recent past can be obtained through the system log for supplementation; when the data generated by the vehicle coupling is less than ten minutes, the data is too little, and the safety control strategy described in this application will not be activated, and the traditional method will be used for coupling control.

[0048] The safety buffer distance between the first train and the second train is obtained through the control system, denoted as .

[0049] The acceleration data of the second train is collected in the same manner as the speed data of the first train; at the same time, the power and mass of the second train are obtained. The resistance of the second train during operation is calculated by the power, mass and acceleration of the second train, wherein the calculation of the resistance is a known technology and the specific process is not repeated here.

[0050] The vector composed of the speed data of the first train at all acquisition moments arranged in ascending time order is recorded as the speed vector. The vector composed of the resistance of the second train calculated at all acquisition moments arranged in ascending time order is recorded as the resistance vector. The nth element in the speed vector represents the running speed of the first train at the nth moment, and the nth element in the resistance vector represents the resistance encountered by the second train at the nth moment.

[0051] The speed vector of the first train, the resistance vector of the second train and the safety buffer distance obtained above are all used as the coupling state information of the second train, and the coupling state information is stored in the operation system of the second train.

[0052] Step S2, dividing the resistance data into discrete intervals based on the numerical range of the vehicle's resistance, setting the state labels of each speed of the neighboring vehicle based on the discrete intervals where each resistance of the vehicle is located; and constructing the probability density function of all speeds of each state label of the neighboring vehicle.

[0053] In the coupled operation mode, trains need to communicate in real time, adjust their own speed through communication information, and remain relatively stationary.

[0054] When communication is interrupted between the first train and the second train, the corresponding coupling status information is obtained through the operation system of the second train, including the speed vector of the first train, the resistance vector of the second train, and the safety buffer distance. The speed vector of the first train is recorded as the speed vector of the adjacent train, and the resistance vector of the second train is recorded as the resistance vector of the own train. At this time, it is necessary to control the own train through a robust control strategy for coping with communication interruption to avoid train collision.

[0055] During the operation of a train, its speed fluctuation is usually related to the environmental conditions, and the impact of the environment on the train speed is usually related to the environmental resistance. Therefore, the speed fluctuation characteristics of the train can be characterized by the resistance change. When the communication between the train and the neighboring train is interrupted, the speed change of the neighboring train can be analyzed according to the resistance change characteristics of the train, and then the running state of the train can be dynamically controlled to prevent safety hazards.

[0056] Even under the same resistance, vehicles will have certain speed fluctuations. Therefore, this embodiment discretizes the resistance and constructs the relationship between the resistance of the vehicle and the speed of the neighboring vehicle through the statistical characteristic relationship between the resistance and the speed.

[0057] (1) Discretize the vehicle resistance data:

[0058] Set the number of discrete intervals, denoted as B. Preferably, in one embodiment of the present application, B is set to 5. As other embodiments of the present application, the implementer can set the value of B according to the actual situation. Obtain the maximum and minimum values ​​of the vehicle's resistance vector, denoted as A and C respectively, and then calculate the difference between A and C, denoted as D. Then, B discrete intervals can be obtained, which are respectively , ,……, , . In which, when the vehicle resistance is in the bth discrete interval, the vehicle is in the bth resistance state. Thus, the resistance is discretized.

[0059] (2) Set the label of each neighboring vehicle’s speed data:

[0060] Through the above discretization, the resistance of the vehicle is divided into B states. In different states, the environment in which the train is running is different. The neighboring vehicle and the vehicle are in the same driving environment. Therefore, when the resistance state of the vehicle changes, the speed of the neighboring vehicle will change accordingly.

[0061] Get the discrete interval of each resistance in the resistance vector, and get the resistance state corresponding to each resistance data of the vehicle. According to the resistance state of each resistance data of the vehicle, set the state label of the speed of the neighboring vehicle at the same time. For example, if the resistance data of the vehicle is in the bth resistance state, then for the speed data of the neighboring vehicle collected at the same time as the resistance data, set the label of the speed data of the neighboring vehicle to state label b.

[0062] (3) Construct the correlation characteristics between the vehicle's resistance state and the speed of the neighboring vehicle:

[0063] Get the element labeled with state label b in the neighboring vehicle speed vector, and calculate the mean and standard deviation of all elements of state label b, which are recorded as and Among them, the mean represents the average size of the train speed under the b-th resistance state; the standard deviation represents the fluctuation error size of the train speed under the b-th resistance state.

[0064] Furthermore, all the neighboring vehicle speed data of state label b and the mean and standard deviation of state label b are used as the input of the one-dimensional Gaussian function model, and the output is a probability density function, which is recorded as Among them, the one-dimensional Gaussian function model is a well-known technology, and the specific process will not be repeated. Function middle, represents the speed of the neighboring car, When the resistance of the vehicle is in the bth resistance state, the speed of the neighboring vehicle is The probability of , so the function The correlation characteristics between the resistance state of the vehicle and the speed of the neighboring vehicle are characterized.

[0065] It should be noted that for the probability density function of all speed data of each state label, this application only provides a method for obtaining a probability density function. There are many existing methods for obtaining probability density functions. Implementers can also use other function models to obtain the probability density function of all speed data of each state label. This application does not make any specific restrictions.

[0066] Step S3, obtaining a preset number of sub-intervals of each probability density function by interval division; and calculating the speed occurrence probability of the neighboring vehicle speed in each sub-interval based on the probability density function in each sub-interval.

[0067] (1) For the convenience of data processing, the function Perform numerical processing:

[0068] First, according to 3 Principle, the function The domain of definition is limited to the range interval Among them, 3 The principle is a well-known technology, and the specific process will not be repeated. It can reduce the amount of data calculation while retaining most of the data features of the Gaussian function model.

[0069] Further, the range interval is divided into E partitions, wherein the speed of the midpoint of each partition is used as the speed of the neighboring vehicle in each partition. Preferably, in one embodiment of the present application, the value of E is set to 10. As other embodiments of the present application, the implementer can set the value of E according to actual conditions. Calculate the function within the e-th partition The integrated area under the curve , which means that when the resistance of the vehicle is in the bth resistance state, the speed of the neighboring vehicle is The probability of , which is used as the appearance weight of the neighboring vehicle speed between the e-th partitions.

[0070] (2) Since this embodiment is based on 3 The principle narrows the function The domain range of the function The sum of the E occurrence weights of is not 1, so this embodiment applies the function The E occurrence weights are normalized so that the sum of the occurrence probabilities of the neighboring vehicle speeds between all partitions is 1. The method is:

[0071] Preferably, in one embodiment of the present application, the method for normalizing the appearance weights of neighboring vehicle speeds between each partition is to sum the appearance weights between all partitions, recorded as the first sum, and the ratio of the appearance weights between each partition to the first sum is the normalized value of the appearance weights between each partition, recorded as the speed appearance probability of the neighboring vehicle speed between each partition.

[0072] It should be noted that there are many existing normalization methods, and implementers may also use other normalization methods to normalize the probability of occurrence of neighboring vehicle speeds between each partition so that the sum of the probability of occurrence of neighboring vehicle speeds between all partitions is 1. This application does not make specific restrictions.

[0073] Step S4, based on the neighboring vehicle speeds between all the partitions of each state tag, construct the neighboring vehicle displacement sequence of the resistance at each moment after the communication is interrupted, obtain various neighboring vehicle displacements at the current moment based on all the neighboring vehicle displacement sequences, and calculate the displacement occurrence probability of various neighboring vehicle displacements at the current moment in combination with the speed occurrence probability.

[0074] (1) The bth resistance state corresponds to state label b. The neighboring vehicle speeds of all the partitions under state label b are sequenced in the order of partitions, and all corresponding speed occurrence probabilities are sequenced in the order of partitions, which are recorded as the neighboring vehicle speed sequence and speed probability sequence of state label b, respectively, to characterize the distribution probability of the neighboring vehicle speed under the bth resistance state. The neighboring vehicle speed sequence and speed probability sequence of each state label are obtained in the above manner.

[0075] (2) Analyze the possible displacement of neighboring vehicles at different times after communication interruption:

[0076] In the virtual coupling mode, the vehicle will continue to receive periodic information from the IP address of the neighboring vehicle. When the vehicle does not receive periodic information, it means that communication is interrupted. After the communication between the vehicle and the neighboring vehicle is interrupted, the vehicle cannot obtain the speed information of the neighboring vehicle. At this time, the speed of the neighboring vehicle can be judged by the resistance information of the vehicle.

[0077] After the communication interruption occurs, the resistance of the vehicle is continuously collected. It is assumed that a resistance vector of length T is collected in the time period between the start time of the communication interruption and the current time, and recorded as the interruption resistance vector at the current time. Preferably, in one embodiment of the present application, the sampling time interval of the resistance in the time period is set to 100 milliseconds. As other embodiments of the present application, the implementer can set the sampling time interval according to the actual situation. Among them, the tth element in the interruption resistance vector represents the resistance of the vehicle at the tth time after the communication interruption.

[0078] Furthermore, after the communication is interrupted, assuming that the resistance of the vehicle at the t-th moment is in the q-th resistance state, first obtain the neighboring vehicle speed sequence of the state label corresponding to the q-th resistance state, and multiply each neighboring vehicle speed in the neighboring vehicle speed sequence by the sampling time interval to obtain each displacement value; all the displacement values ​​of the neighboring vehicle speed sequence form a sequence, which is recorded as the neighboring vehicle displacement sequence, representing the displacement size that may occur in the neighboring vehicle at the t-th moment.

[0079] (3) Analyze the displacement probability distribution of neighboring vehicles at the current moment after communication interruption:

[0080] First, at the current moment, we can obtain T neighboring vehicle displacement sequences. To analyze the displacement of the neighboring vehicle from the beginning of the communication interruption to the current moment, we take one displacement value from each of the T neighboring vehicle displacement sequences and combine them. There are permutations and combinations. For the g-th permutation and combination, the result obtained by summing up all the selected displacement values ​​is recorded as the displacement of the neighboring vehicle from the beginning of communication interruption to the current moment under this permutation and combination, and is recorded as the neighboring vehicle displacement of the g-th permutation and combination; for the g-th permutation and combination, the speed occurrence probability of all the selected displacement values ​​in the corresponding speed probability sequence is multiplied, and the result obtained represents the combination occurrence probability of the g-th permutation and combination. Among them, the cumulative multiplication operation refers to the operation of multiplying all element values. The neighboring vehicle displacement generated by each permutation and combination and the corresponding combination occurrence probability are obtained by the above method.

[0081] Then, all the permutations and combinations of neighboring car displacements with the same size are classified into one category, and various neighboring car displacements at the current moment are obtained. Assuming that there are H types of neighboring car displacements at the current moment, the displacement probability of each type of neighboring car displacement at the current moment is analyzed:

[0082] The sum of the combined occurrence probabilities of all permutations and combinations of the displacements of each type of neighboring vehicle at the current moment is taken as the displacement occurrence probability of each type of neighboring vehicle at the current moment.

[0083] Finally, from the time when the communication is interrupted to the current moment, the neighboring vehicle may have H types of displacements due to speed fluctuations, where the probability of the displacement of the hth type of neighboring vehicle at the current moment is recorded as .

[0084] Step S5, based on the displacement of the vehicle at the current moment and the displacements of various neighboring vehicles at the current moment, various relative displacements between the neighboring vehicle and the vehicle at the current moment are obtained; based on the speed of the vehicle at the start of the communication interruption and the length of time to the current moment, the virtual position of the vehicle at the current moment is determined; based on the displacement occurrence probability of the neighboring vehicle displacement corresponding to various relative displacements, combined with the virtual position of the vehicle, the collision probability between the vehicle and the neighboring vehicle when the neighboring vehicle is at each preset position at the current moment is constructed; based on the collision probability at all preset positions and the safety buffer distance, the collision safety factor of the vehicle at the current moment is determined.

[0085] (1) Analyze the possible relative displacement between the neighboring vehicle and the vehicle from the time when the communication is interrupted to the current moment:

[0086] Obtain the displacement of the vehicle from the beginning of the communication interruption to the current moment, and record it as the displacement of the vehicle at the current moment; subtract the displacement of the vehicle at the current moment from the displacement of the h-th neighboring vehicle at the current moment, and record the result as the h-th relative displacement between the neighboring vehicle and the vehicle at the current moment. The probability of occurrence of this type of relative displacement is , represents the current moment of the neighboring car and the vehicle The relative displacement is likely to occur. At this time, the distance between the vehicle and the adjacent vehicle should be at least greater than the relative displacement to avoid the safety accident of train collision. The above method is used to obtain various relative displacements between the adjacent vehicle and the vehicle at the current moment.

[0087] Among them, if the hth type of relative displacement between the neighboring vehicle and the vehicle at the current moment is greater than 0, it means that the displacement of the neighboring vehicle is greater than the displacement of the vehicle. The probability of being in front of the neighboring car's virtual position; if it is less than 0, it means that the neighboring car is behind the neighboring car's virtual position with this probability.

[0088] (2) When the neighboring vehicle When the probability of being at a certain point, the car should be to the left of the neighboring car at this time. The collision probability of the neighboring car at each position is analyzed based on the displacement occurrence probability of various relative displacements corresponding to the neighboring car:

[0089] For the vehicle and the neighboring vehicle, there are H relative displacements at the current moment, and each relative displacement has a corresponding displacement probability. First, the position of the vehicle on the track at the beginning of the communication interruption is obtained through the control system of the vehicle, which is recorded as , and the vehicle's speed at the beginning of the communication interruption, recorded as ; Then get the length of time from the communication interruption to the current moment, recorded as ; Finally, the virtual position of the vehicle at the current moment can be obtained as: ;

[0090] Furthermore, assuming that the neighboring vehicle is at coordinate point x at the current moment, obtain the distance between coordinate point x and the virtual position of the vehicle at the current moment ;

[0091] Furthermore, when the neighboring vehicle is at coordinate point x, the calculation process of the collision probability between the vehicle and the neighboring vehicle is:

[0092] Among all the relative displacements of the classes, the relative displacement value is less than The relative displacement of the neighboring car is taken as the collision-prone relative displacement when the neighboring car is at coordinate point x; the sum of the displacement occurrence probabilities of all types of collision-prone relative displacements at this time is calculated and recorded as the collision probability between the vehicle and the neighboring car at this time, and the collision probability between the vehicle and the neighboring car is expressed as The collision probability means that if the neighboring car appears at the coordinate point x at the current time, the neighboring car has The probability of colliding with this vehicle.

[0093] (3) Obtain the maximum and minimum values ​​of all types of relative displacements between the neighboring vehicle and the vehicle at the current moment, and record them as the maximum relative displacement and the minimum relative displacement , then the value range of the coordinate point x of the neighboring car at the current moment is , recorded as the location area of ​​the neighboring vehicle at the current moment. It is the safety buffer distance obtained in step S1.

[0094] For the convenience of calculation, the embodiment of the present application evenly takes X coordinate points in the position area, that is, the first coordinate point is at the leftmost side of the position area, the Xth coordinate point is at the rightmost side of the position area, and the remaining coordinate points are evenly distributed at the same interval in the position area. Preferably, in one embodiment of the present application, the value of X is set to 100. As other embodiments of the present application, the implementer can set the value of X according to actual conditions.

[0095] (4) Calculate the collision safety factor of the vehicle at the current moment:

[0096] At the current moment, the vehicle should maintain a certain safe distance from the neighboring vehicle, so the collision safety factor is calculated to represent the risk of collision of the vehicle at the current moment:

[0097]

[0098] In the formula, is the collision safety factor of the vehicle at the current moment, X is the number of coordinate points selected in the position area of ​​the neighboring vehicle at the current moment, is the collision probability when the neighboring vehicle is at the z-th coordinate point in the position area at the current moment, It is the distance between the virtual position of the vehicle at the current moment and the zth coordinate point in the position area.

[0099] The farther the virtual position of the vehicle is from the collision area at the current moment, and the greater the probability of no collision, the greater the collision safety factor. Since the collision safety factor is obtained by summing the distance multiplied by the probability, the physical quantity corresponding to the collision safety factor of this embodiment is the distance, and the safety buffer distance can be used. As an evaluation criterion, when the collision safety factor is greater than or equal to the safety buffer distance, it is determined that there is sufficient buffer space between the vehicle and the adjacent vehicle at the current moment to deal with emergencies, which can ensure safe virtual coupling of trains.

[0100] Step S6, performing train safety coupling control based on the collision safety factor and safety buffer distance of the vehicle at the current moment.

[0101] In the case of communication interruption between the vehicle and the vehicle ahead, if the collision safety factor of the vehicle at the current moment is less than the safety buffer distance, the vehicle's speed is controlled and adjusted to place the vehicle at a position where the collision safety factor is greater than the safety buffer distance, leaving enough buffer space for sudden vehicle conditions. When the collision safety factor is greater than or equal to the safety buffer distance, the vehicle's speed does not need to be adjusted.

[0102] In particular, when the communication interruption time continues to exceed the threshold of 30 seconds, it is determined that there is a high probability of a collision between the trains at this time, and the coupling should be cancelled, the moving block mode should be entered, and the virtual coupling should be re-established. The implementer can set the threshold according to the actual situation, and this embodiment does not impose any special restrictions.

[0103] Finally, when the periodic information sent from the IP address of the neighboring vehicle is detected again through Ethernet, the speed of the vehicle is controlled again so that the vehicle and the neighboring vehicle are connected at a safe buffer distance and in a relatively static posture.

[0104] The schematic diagram of the process of obtaining the displacement probability of the neighboring vehicle at the current moment is as follows: Figure 2 shown.

[0105] In summary, the embodiment of the present application performs virtual coupling of trains by exchanging information between trains, records each train as the own train, and records the previous train of each train as the neighboring train; based on the relationship between the resistance of the own train and the speed of the neighboring train when communication is normal, and the probability distribution of the neighboring train speed, a neighboring train speed sequence of the state label corresponding to each own train resistance is constructed, and the correlation characteristics between the own train resistance and the neighboring train speed are analyzed, so as to achieve the effect of estimating the neighboring train speed based on the own train resistance; when communication is interrupted, the probability of the neighboring train position and displacement is calculated according to the correlation characteristics between the own train resistance and the neighboring train speed, and the neighboring train speed caused by speed fluctuation is characterized. It may appear in different positions, as well as the probability of displacement at each position; the collision safety factor is calculated based on the position and displacement probability of the adjacent vehicle to characterize the risk of collision between the vehicle and the adjacent vehicle; finally, based on the collision safety factor, a robust safety control strategy is constructed to complete the safety control of the train coupling, taking into account the speed error problem of the adjacent vehicle due to the environment, feature extraction is used to obtain the correlation characteristics of the train data, and the speed error of the adjacent vehicle is estimated through the operating data of the vehicle to appropriately adjust the position of the vehicle, which can avoid the hidden danger of train collision caused by the control distance error due to communication interruption and reduce the risk of train collision.

[0106] It should be noted that the above-mentioned sequence of the embodiments of the present application is only for description and does not represent the advantages and disadvantages of the embodiments. The above-mentioned specific embodiments of the present application are described. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0107] The various embodiments in the present application are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0108] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Modifications to the technical solutions recorded in the aforementioned embodiments, or equivalent replacement of some of the technical features therein, do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A train safety coupling control method based on Ethernet, characterized in that: The method comprises the following steps: The train to be controlled is recorded as the own train, and the train before the own train is recorded as the neighboring train; the speed of the neighboring train at each moment, the resistance of the own train at each moment, and the safety buffer distance under the coupling operation mode are collected; Based on the numerical range of the vehicle's resistance, the resistance data is divided into discrete intervals, and the state labels of the speeds of neighboring vehicles are set based on the discrete intervals where the resistances of the vehicle are located; the probability density function of all speeds of the state labels of the neighboring vehicles is constructed; Obtain a preset number of sub-intervals of each probability density function by dividing the intervals; calculate the speed occurrence probability of the speed of the neighboring vehicle in each sub-interval based on the probability density function in each sub-interval; Based on the neighboring vehicle speeds of all the partitions of each state tag, a neighboring vehicle displacement sequence of resistance at each moment after communication interruption is constructed; based on all the neighboring vehicle displacement sequences, various neighboring vehicle displacements at the current moment are obtained; and combined with the speed occurrence probability, the displacement occurrence probability of various neighboring vehicle displacements at the current moment is calculated; Based on the displacement of the vehicle at the current moment and the displacement of various neighboring vehicles at the current moment, various relative displacements between the neighboring vehicle and the vehicle at the current moment are obtained; based on the speed of the vehicle at the start of the communication interruption and the length of time to the current moment, the virtual position of the vehicle at the current moment is determined; based on the displacement occurrence probability of the neighboring vehicle displacement corresponding to various relative displacements, combined with the virtual position of the vehicle, the collision probability between the vehicle and the neighboring vehicle when the neighboring vehicle is at each preset position at the current moment is constructed; based on the collision probability and safety buffer distance at all preset positions, the collision safety factor of the vehicle at the current moment is determined; Train safety coupling control is carried out based on the collision safety factor and safety buffer distance of the vehicle at the current moment.

2. The Ethernet-based train safety coupling control method according to claim 1, characterized in that: The process of dividing the discrete intervals is as follows: The number of preset discrete intervals is recorded as B; the maximum and minimum values ​​of the vehicle's resistance at all times are obtained; the difference between the maximum and minimum values ​​is recorded as D, and the discrete intervals are , ,……, , , where C is the minimum value.

3. The Ethernet-based train safety coupling control method according to claim 1, characterized in that: The method for setting the status labels of the speeds of the neighboring vehicles is as follows: If any resistance of the vehicle is in the bth discrete interval, the speed of the neighboring vehicle at the same moment as any resistance of the vehicle is set as state label b.

4. The Ethernet-based train safety coupling control method according to claim 1, characterized in that: The process of obtaining the speed occurrence probability of the adjacent vehicle speed between each partition is as follows: For each of the partitions of each state label, the speed of the midpoint of the partition is used as the neighboring vehicle speed of the partition, and the normalized value of the integral area of ​​the probability density function within the partition is used as the speed occurrence probability of the neighboring vehicle speed of the partition.

5. The Ethernet-based train safety coupling control method according to claim 1, characterized in that: The process of obtaining the displacement occurrence probability of each type of neighboring vehicle displacement at the current moment is as follows: The product of each neighboring vehicle speed in the neighboring vehicle speed sequence of each state label and the sampling time interval is used as each displacement value; all the displacement values ​​of the neighboring vehicle speed sequence are combined into a sequence to obtain the neighboring vehicle displacement sequence of each state label; For the resistance of the vehicle at each moment after the communication is interrupted, the displacement sequence of the neighboring vehicle corresponding to the state label of the discrete interval where the resistance of the vehicle is located is obtained as the displacement sequence of the neighboring vehicle of the resistance of the vehicle; During the period from the beginning of the communication interruption to the current moment, a displacement value is taken from each displacement sequence of the neighboring vehicle of the vehicle's resistance at all moments to be combined to obtain various permutations and combinations; the sum of all displacement values ​​selected from various permutations and combinations is used as the current neighboring vehicle displacement of various permutations and combinations; the product of the speed occurrence probabilities of the neighboring vehicle speeds between the partitions corresponding to all displacement values ​​selected from various permutations and combinations is used as the combination occurrence probability of various permutations and combinations; All permutations and combinations of neighboring vehicle displacements of the same magnitude are classified into one category to obtain various neighboring vehicle displacements at the current moment; the sum of the combined occurrence probabilities of all permutations and combinations of various neighboring vehicle displacements at the current moment is taken as the displacement occurrence probability of various neighboring vehicle displacements at the current moment.

6. The Ethernet-based train safety coupling control method according to claim 1, characterized in that: The various relative displacements between the neighboring vehicle and the vehicle at the current moment are: The displacement of the vehicle from the beginning of the communication interruption to the current moment is obtained, which is recorded as the displacement of the vehicle at the current moment; the difference between the displacement of each type of neighboring vehicle at the current moment and the displacement of the vehicle at the current moment is taken as the relative displacement between the neighboring vehicle and the vehicle at the current moment.

7. The Ethernet-based train safety coupling control method according to claim 1, characterized in that: The virtual position of the vehicle at the current moment is: The position of the vehicle at the beginning of communication interruption is recorded as ; The vehicle's speed at the beginning of the communication interruption is recorded as ; The time from the communication interruption to the current time is recorded as ; The virtual position of the vehicle at the current moment The calculation method is: .

8. The Ethernet-based train safety coupling control method according to claim 1, characterized in that: The process of obtaining the collision probability between the vehicle and the neighboring vehicle when the neighboring vehicle is at each preset position at the current moment is: Assume that the neighboring car is at coordinate point x at the current moment, and obtain the distance between coordinate point x and the virtual position of the current car, which is recorded as ; Among all the relative displacements of the classes, obtain the relative displacement value less than The relative displacement of the neighboring car is taken as the collision-probable relative displacement when the neighboring car is at coordinate point x; the sum of the displacement occurrence probabilities of all the collision-probable relative displacements is taken as the collision probability between the vehicle and the neighboring car when the neighboring car is at coordinate point x.

9. The Ethernet-based train safety coupling control method according to claim 1, characterized in that: The process of obtaining the collision safety factor of the vehicle at the current moment is: The safety buffer distance between the vehicle and the neighboring vehicle is recorded as , the maximum and minimum values ​​of all types of relative displacements between the neighboring vehicle and the vehicle at the current moment are recorded as and , the value range As the location area of ​​the neighboring vehicle at the current moment, is the virtual position of the vehicle at the current moment; The collision safety factor of the vehicle at the current moment is recorded as , The expression is: , where X is the number of coordinate points selected in the neighboring vehicle position area at the current moment, is the collision probability when the neighboring vehicle is at the z-th coordinate point in the position area at the current moment, It is the distance between the virtual position of the vehicle at the current moment and the zth coordinate point in the position area.

10. The Ethernet-based train safety coupling control method according to claim 1, characterized in that: The train safety coupling control based on the collision safety factor and safety buffer distance of the vehicle at the current moment is specifically as follows: In the case of communication interruption, if the collision safety factor of the vehicle at the current moment is less than the safety buffer distance, the speed of the vehicle is controlled and adjusted so that the vehicle is in a position where the collision safety factor is greater than the safety buffer distance; otherwise, the speed of the vehicle is not adjusted.

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