Freight train operation stability evaluation system

Abstract

The invention discloses a freight train operation stability evaluation system which comprises a plurality of stability data acquisition devices distributed along a train and a ground comprehensive evaluation unit. The stability data acquisition device comprises a CPU board, an acceleration sensor, a laser sensor, a GPS device, an automobile data recorder, a data acquisition state display module and a power supply module. And the ground comprehensive evaluation unit performs data interaction with the stability data acquisition device, and calculates and evaluates the stability by using the data acquired by the stability data acquisition device. Compared with the prior art, the stability data acquisition device has the technical advantages that information acquired by the stability data acquisition device is more comprehensive, the local stability of the train can be evaluated according to data of a single stability data acquisition device, and the overall stability of the train can also be evaluated according to data of multiple stability data acquisition devices; the driving level of a driver and the advantages and disadvantages of an automatic driving algorithm can be evaluated according to the train operation stability.

Description

Technical Field

[0001] The invention relates to the field of train dynamics, and in particular to a freight train running stability assessment system and assessment method. Background Art

[0002] Railway freight trains are basically composed of a locomotive and several vehicles connected by a coupler buffer device. However, the power transmission is complicated during the train start, acceleration, and braking process. In addition, the impact forces in various directions caused by various operations during each operation process will not only cause the vehicle to not run smoothly, but in serious cases, even cause the coupler to break, causing serious train safety accidents. Therefore, it is necessary to effectively monitor the impulses in various directions brought by the train during operation and evaluate its stability.

[0003] Currently, there is no equipment or method for comprehensively collecting and processing the stability data during train driving. Most of them only focus on acceleration or use a single coupler buffer displacement for analysis. Although some examples of comprehensive analysis of acceleration and coupler buffer displacement are mentioned, there is no comprehensive analysis of stability in combination with various driving status data and electronic maps during train driving. Summary of the invention

[0004] In order to overcome the deficiencies of the prior art, the present invention provides a system and method capable of accurately evaluating the running stability of a freight train.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A freight train running stability evaluation system comprises a plurality of stability data acquisition devices and a ground comprehensive evaluation unit which are distributed along the vehicle; the stability data acquisition device comprises: a CPU board, an acceleration sensor, a laser sensor, a GPS device, a driving recorder, a data acquisition status display module and a power module; the acceleration sensor is used to collect the longitudinal acceleration, lateral acceleration, vertical acceleration, pitch angle, roll angle, yaw angle and angular velocity around three axes of the carriage; the laser sensor is used to collect the distance between two adjacent carriages; the GPS device is used as a clock module to provide system time and collect the current time and longitude; the CPU board communicates with the acceleration sensor, the laser sensor and the GPS device through a serial port; the driving recorder is used to record the coupling status between two adjacent carriages; the ground comprehensive evaluation unit exchanges data with the stability data acquisition device, and uses the data collected by the stability data acquisition device to calculate and evaluate the stability.

[0007] Furthermore, the ground comprehensive evaluation unit also exchanges data with the locomotive driving status acquisition equipment, and performs calculation and evaluation of stability in combination with the locomotive driving status data and the electronic high-definition map.

[0008] The ground comprehensive evaluation unit includes a data processing unit, a free gap state determination unit, a spacing correction unit, a relative acceleration and relative displacement calculation unit, a data validity judgment unit, and a stability calculation and evaluation unit; the data processing unit also includes a data alignment unit, a data preprocessing unit and a true value calculation unit.

[0009] The data alignment unit aligns the data collected by a single stability data acquisition device, aligns the corresponding data collected by multiple stability data acquisition devices, and aligns the data of the stability data acquisition device with the locomotive driving status data according to the time provided by the GPS device; at the same time, the data of the stability data acquisition device is aligned with the electronic high-definition map according to the time and longitude and latitude provided by the GPS device, so that the geographical location of the current data can be displayed, and it can be matched with the specific mileage in the railway line data to obtain the line parameters of the location.

[0010] The data preprocessing and true value calculation unit performs data preprocessing on the pitch angle, the roll angle and the yaw angle, and performs true value calculation on the longitudinal acceleration, the lateral acceleration, the vertical acceleration, the pitch angle, the roll angle and the yaw angle.

[0011] The free gap state determination unit is used to analyze the image recorded by the driving recorder, so as to determine the free gap state C of the coupler. The free gap state of the coupler is divided into a free state, a pressed hook state and a pulled hook state.

[0012] The spacing correction unit uses a video processing algorithm to analyze the image recorded by the driving recorder, calculates the current coupler bending angle, and then corrects the spacing L between two adjacent carriages collected by the laser sensor.

[0013] The relative acceleration and relative displacement calculation unit calculates the relative acceleration Δa using the longitudinal acceleration, lateral acceleration, vertical acceleration, pitch angle, roll angle and yaw angle between the front and rear carriages, and calculates the relative displacement ΔL using the corrected carriage spacing L between the two adjacent carriages.

[0014] The data validity judgment unit receives the relative acceleration Δa, relative displacement ΔL and coupler free clearance state C. Before the stability calculation and evaluation unit starts calculation, the validity of the Δa and ΔL data is first judged using the method described in the previous patent CN202210850080.4. If the data is valid, it is sent to the stability calculation and evaluation unit for calculation; if the data is invalid, it is not sent to the stability calculation and evaluation unit, and according to the invalid situation, the data is deleted or a signal of unstable train operation is directly given.

[0015] The stability calculation and evaluation unit performs calculation and evaluation of local stability and overall stability; the local stability calculation and evaluation uses the effective relative acceleration Δa and relative displacement ΔL corresponding to a single stability data acquisition device to perform stability calculation, specifically, the received discrete Δa and ΔL data are curve-fitted to obtain a Δa-ΔL curve, and the area of ​​the figure enclosed by the Δa-ΔL curve and the ΔL coordinate axis is calculated, thereby obtaining a local stability index S. And combined with GPS time, GPS longitude and latitude, locomotive driving status data and electronic high-definition map, it is determined that the stability is a stability index of the train in what state and at what position on the line; the overall stability calculation and evaluation uses the data of the several stability data acquisition devices, that is, after completing the local stability calculation and evaluation, a comprehensive judgment is made according to the stability index corresponding to each stability data acquisition device.

[0016] The present invention also provides a method for evaluating the running stability of a freight train, the method comprising: arranging a plurality of stability data acquisition devices distributed along the vehicle, each of the stability data acquisition devices collecting information such as time, longitude and latitude, longitudinal acceleration, lateral acceleration, vertical acceleration, pitch angle, roll angle, yaw angle, angular velocity around three axes, carriage spacing, and coupler status; aligning the above-collected information; performing data preprocessing and true value calculation on acceleration sensor related data to obtain true values ​​of longitudinal acceleration, lateral acceleration, vertical acceleration, pitch angle, roll angle, and yaw angle; determining the free gap state C of the coupler based on the video of the driving recorder; correcting the spacing L between two adjacent carriages collected by the laser sensor based on the video of the driving recorder, and correcting the spacing L between the front and rear carriages based on the longitudinal acceleration between the front and rear carriages. The relative acceleration Δa is calculated based on the speed, lateral acceleration, vertical acceleration, pitch angle, roll angle and yaw angle, and the relative displacement ΔL is calculated based on the corrected car spacing L between two adjacent cars. The data validity is judged based on the relative acceleration Δa, relative displacement ΔL and the free clearance state C of the coupler. Finally, the stability index is calculated based on the effective relative acceleration Δa and relative displacement ΔL. The received discrete Δa and ΔL data are curve fitted to obtain the Δa-ΔL curve, and the area of ​​the figure enclosed by the Δa-ΔL curve and the ΔL coordinate axis is calculated to obtain the local stability index S. The local stability is comprehensively calculated and evaluated based on the GPS time, GPS longitude and latitude, locomotive driving status data and electronic high-definition map. Finally, the overall stability is calculated and evaluated using several stability indicators.

[0017] The technical advantages of the present invention are: 1) Compared with the prior art, the stability data acquisition device of the present invention collects more comprehensive information, including running time, running position (latitude and longitude), acceleration, angle, car spacing and coupler free clearance status, and can also be combined with various driving status data during the train operation for analysis, while the previous information collection during the train operation was relatively one-sided and could not reflect the overall picture of the train operation. 2) The present invention can not only evaluate the local stability of the train based on the data of a single stability data acquisition device, but also evaluate the overall stability of the train based on the data of multiple stability data acquisition devices. 3) The present invention can evaluate the driver's driving level and the advantages and disadvantages of the automatic driving algorithm based on the stability of the train operation, thereby providing a solid foundation for the research of key control algorithms for automatic driving. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention, the figures required for use in the embodiments will be briefly introduced below. Obviously, the figures described below are only some embodiments of the present invention. For ordinary technicians in this field, other figures can be obtained based on these figures without paying creative work.

[0019] Figure 1 This is a schematic diagram of the structure of the freight train running stability assessment system;

[0020] Figure 2 It is a schematic diagram of the structure of the stability data acquisition device;

[0021] Figure 3 It is a schematic diagram of the power supply for the stability data acquisition device;

[0022] Figure 4 This is a schematic diagram of the structure of the ground comprehensive assessment unit;

[0023] Figure 5 This is a schematic diagram of the longitudinal acceleration analysis of a freight train when going uphill;

[0024] Figure 6 This is a schematic diagram of the vertical acceleration analysis of a freight train when going uphill; DETAILED DESCRIPTION

[0025] The following will be combined with the figures of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the protection scope of the present invention.

[0026] like Figure 1As shown, the freight train running stability evaluation system of the present invention includes a number of stability data acquisition devices (i.e., stability data acquisition device 1, stability data acquisition device 2...stable data acquisition device N) distributed along the vehicle and a ground comprehensive evaluation unit. According to one embodiment of the present invention, the stability data acquisition devices include three, which are respectively arranged at the connection between the head locomotive and the vehicle, the middle and the tail of the train formation, because these three positions are the places where the train can best reflect the running stability of the train under traction, braking, brake relief, uphill and downhill conditions. The ground comprehensive evaluation unit exchanges data with the stability data acquisition device, and uses the data collected by the stability data acquisition device to perform calculation and evaluation of stability; further, the ground comprehensive evaluation unit also exchanges data with the locomotive driving status acquisition device, and combines the locomotive driving status data and the electronic high-definition map to perform calculation and evaluation of stability.

[0027] like Figure 2 As shown, the stability data acquisition device includes: a CPU board, an acceleration sensor, a laser sensor, a GPS device, a driving recorder, a data acquisition status display module and a power module. The acquisition device integrates multiple sensor devices together, which is easy to operate and carry.

[0028] Since the stability data acquisition device integrates various sensors and other components together and fixes them in the outer shell with screws, there is no need to install each part one by one. When the integrated stability data acquisition device is installed, the magnetic block on its back is used to adsorb the device to the outer surface of the front end of the freight train car to complete the installation of the freight train stability data acquisition device. Several stability data acquisition devices are installed in the same way.

[0029] The power supply is fixedly connected to the back of the stability data acquisition device to supply power to each module in the stability data acquisition device. It has a main power switch to control the power supply. The specific power supply is divided into 12V DC power supply and 5V DC power supply, which share a common ground. The 12V DC power supply supplies power to the acceleration sensor and the CPU board, and the 5V power supply supplies power to the laser sensor, GPS device and driving recorder. The two types of power supplies are powered by a circular 12V power charging port 4 and an oval 5V power charging port, respectively. Figure 3 shown.

[0030] The data acquisition status display module includes 3 indicator lights to indicate the status of the freight train stability data acquisition device. One indicator light is used to determine whether the power supply has been supplied to each sensor, that is, whether the power supply has supplied power to the acceleration sensor, laser sensor, GPS device, driving recorder and CPU board; the second indicator light is used to confirm whether the acceleration sensor, laser sensor and GPS device can communicate with the CPU board; the third indicator light is used to indicate whether the GPS device can search for satellites and obtain GPS data including at least time. The three indicator lights are independent and are not affected by each other.

[0031] The acceleration sensor is horizontally fixed to the bottom of the stability data acquisition device, with its x-axis direction vertically facing the front of the stability data acquisition device and its z-axis direction vertically facing the bottom of the stability data acquisition device. It is used to collect the longitudinal acceleration, lateral acceleration, vertical acceleration, pitch angle, roll angle, and yaw angle of the current carriage, where the longitudinal acceleration is the x-axis acceleration a in the forward direction of the freight train. x Direction, lateral acceleration a y is the horizontal direction, and the vertical acceleration a z is the vertical downward direction, the pitch angle is the angle of rotation around the y-axis, the roll angle is the angle of rotation around the x-axis, and the yaw angle is the angle of rotation around the z-axis.

[0032] Due to its size, the laser sensor is fixedly connected to the top of the stability data acquisition device. It is used to collect the distance between the carriage adsorbed by the stability data acquisition device of the freight train and the previous carriage, that is, the distance traveled by the laser from the front end of the rear carriage to the rear end of the front carriage. Since the GPS device inside the stability data acquisition device is prone to cause problems in satellite search, it is fixed to the top of the stability data acquisition device. On the one hand, it is considered as a clock module for time collection with a recording period of 20ms to ensure the synchronization of the collected data in time. On the other hand, it simultaneously collects the current time latitude and longitude, which is convenient for the subsequent viewing of the geographical location of the collected data in the high-definition map.

[0033] A part of the driving recorder is inside the stability data acquisition device and is used to connect the cable for power supply, and a part of it is outside the stability data acquisition device for video recording. The driving recorder video is saved in the driving recorder dedicated TF card for transmission to the free gap state determination unit and the spacing correction unit in the ground comprehensive evaluation unit.

[0034] The CPU board is fixed to the inside of the stability data acquisition device through four studs. It is the central data processing unit of the freight train stability data acquisition device. It can communicate with the acceleration sensor, laser sensor and GPS device through serial ports. Since the sensor data has GPS time data, the acceleration, laser sensor and GPS data at the same time can be obtained to facilitate subsequent data analysis and processing.

[0035] The CPU board also controls the display of the indicator light status in the data acquisition status display module.

[0036] The ground comprehensive evaluation unit includes a data processing unit, a free gap state determination unit, a spacing correction unit, a relative acceleration and relative displacement calculation unit, a data validity determination unit, and a stability calculation evaluation unit. The data processing unit also includes a data alignment unit, a data preprocessing unit, and a true value calculation unit. Figure 4 shown.

[0037] The data alignment unit performs spatial and temporal alignment on the data, namely: 1) aligning the data of each stability data acquisition device according to the time recorded by the GPS device, so as to obtain the data collected by a single stability data acquisition device at the same time; 2) aligning the corresponding data collected by multiple stability data acquisition devices according to the recorded GPS time; 3) aligning the data of the stability data acquisition device and the locomotive driving status data according to time, so as to facilitate the subsequent comprehensive stability evaluation; 4) aligning the data of the stability data acquisition device with the electronic high-definition map, so as to display the geographical location of the current data, and match it with the specific mileage in the railway line data, so as to obtain the line parameters (including slope and curve) of the location.

[0038] The data from the stability data acquisition device is aligned with the electronic high-definition map based on the longitude and latitude data recorded by the GPS. Since GPS time and longitude and latitude correspond one to one, the longitude and latitude at the same time can be imported into the electronic high-definition map.

[0039] The data preprocessing and true value calculation unit performs preprocessing and true value calculation on the data.

[0040] Regarding data preprocessing, for the pitch angle (α y1 , α y2 , α y3 ), rolling angle (β x1 , β x2 , β x3 ) and yaw angle (γ z1 , γ z2 , γ z3) are filtered at three angles. In order to effectively reduce the noise in the data, the Kalman filter method is selected. Kalman filtering can dynamically adjust the estimated value of the data by combining the current observation value with the previous state prediction, thereby improving the stability and accuracy of the data. Through this filtering algorithm, the data retains the original trend while the noise is effectively filtered, making the angle data smoother and more reliable.

[0041] Regarding the true value calculation, it is divided into angle true value calculation and acceleration true value calculation, that is, true value calculation is performed for longitudinal acceleration, lateral acceleration, vertical acceleration, pitch angle, roll angle, and yaw angle.

[0042] First of all, in the calculation of the true value of the angle, the stability is taken into account. There is a period of time between the installation of the data acquisition device in the freight train car and the departure of the freight train, that is, the period of time Δt before the departure, and the number of data corresponding to this period of time is expressed as N. Taking into account that during this period of time, there are some data that are not 0, this part of the data should be subtracted to obtain the true value relative to the initial state before the departure. The initial state is assumed to be in a flat slope state before the freight train departs, and the average value of the data before the departure is obtained. Moreover, after the departure, whether it is uphill, downhill or flat, it has little effect on the pitch angle, roll angle and yaw angle, and its true value is also a change relative to the initial state.

[0043] Secondly, when calculating the true value of acceleration, it is also necessary to consider the period before departure to obtain the true value relative to the initial state before departure. In addition to the initial state, the calculation of the true value of acceleration after departure also needs to consider the uphill and downhill conditions. After departure, whether it is uphill, downhill or flat, it has little effect on the lateral acceleration, and its true value is also a change relative to the initial state. Therefore, when going uphill and downhill after departure, what needs to be dealt with more is the longitudinal acceleration and vertical acceleration.

[0044] like Figure 5 As shown in the figure, it is the first position of the freight train when it goes uphill after departure, where the acceleration a x1 Represents the raw value of longitudinal acceleration.

[0045] Considering that the default state before departure is flat, the vertical acceleration in is the initial state value of the vertical acceleration.

[0046] In addition to considering the data relative to the initial state, the calculation of the true value of the longitudinal acceleration after the vehicle starts also needs to consider the acceleration g z1 The influence of the pitch angle α is less than or equal to 90° in practice, that is, the uphill is negative and the downhill is positive. Figure 5 The true value a″ of the longitudinal acceleration at the first position uphill can be obtained x1 The formula is:

[0047]

[0048] where a″ x1 is the true value of the longitudinal acceleration at the first position calculated, a x1 is the initial state of the longitudinal acceleration at the first position, α″ y1 is the true value of the pitch angle at the first position.

[0049] The actual value of the vertical acceleration when going uphill at the first position is calculated as follows Figure 6 As shown, similarly, after the start of the vehicle, in addition to considering the data relative to the initial state, the vertical acceleration also needs to consider the acceleration g z1 In practice, the absolute value of the pitch angle α is less than or equal to 90°, that is, it is negative when going uphill and positive when going downhill. Figure 6 The true value of the vertical acceleration at the first position a″ can be obtained z1 The formula is:

[0050]

[0051] where a″ z1 is the true value of vertical acceleration, a z1 is the initial state of the vertical acceleration at the first position.

[0052] Similarly, the formula for calculating the true value of the longitudinal acceleration and the true value of the vertical acceleration when the first position is downhill can be derived, and the formula is the same as the formula for calculating the true value of the longitudinal acceleration and the true value of the vertical acceleration when the first position is uphill. The principle of calculating the true value of the longitudinal acceleration and the true value of the vertical acceleration at other positions is the same.

[0053] The free gap state determination unit is used to analyze the image recorded by the driving recorder to determine the free gap state C of the coupler. The free gap state of the coupler is divided into free state, hook pressing state and hook pulling state. The spacing correction unit uses a video processing algorithm to analyze the image recorded by the driving recorder, calculates the current bending angle of the coupler, and then corrects the carriage spacing L.

[0054] The relative acceleration and relative displacement calculation unit uses the longitudinal acceleration, lateral acceleration, vertical acceleration, pitch angle, roll angle and yaw angle between the front and rear carriages to calculate the relative acceleration Δa, and uses the corrected carriage spacing L between the two adjacent carriages to calculate the relative displacement ΔL. Since the longitudinal acceleration is mainly used in the relative acceleration, the previous patent CN202210850080.4 not only does not consider the problem of calculating the true value of acceleration, but is also relatively vague in the relative acceleration calculation, and does not consider the problem of inconsistent directions between the two adjacent carriages. Here, when calculating adjacent accelerations, the longitudinal acceleration of the previous carriage is used as the standard, and the rear carriage needs to decompose the longitudinal acceleration, lateral acceleration and vertical acceleration of the rear carriage according to the direction (pitch angle, roll angle, yaw angle) of the previous carriage to the same direction as the direction of the previous carriage. This acceleration is used as the longitudinal acceleration of the rear carriage to calculate the relative acceleration Δa. The relative displacement ΔL is obtained by subtracting the normal distance between two adjacent carriages from the corrected carriage spacing L. It is not directly calculated using the carriage spacing L as in the previous patent CN202210850080.4, in which the normal distance between two adjacent carriages refers to the distance between two adjacent carriages when the coupler gap is in a free state and the coupler buffer is neither stretched nor compressed.

[0055] The data validity judgment unit receives the relative acceleration Δa, relative displacement ΔL and coupler free clearance state C. Before the stability calculation and evaluation unit starts calculation, the validity of the Δa and ΔL data is first judged using the method described in the previous patent CN202210850080.4. If the data is valid, it is sent to the stability calculation and evaluation unit for calculation; if the data is invalid, it is not sent to the stability calculation and evaluation unit, and according to the invalid situation, the data is deleted or a signal of unstable train operation is directly given.

[0056] The stability calculation and evaluation unit performs calculation and evaluation of local stability and overall stability; the local stability calculation and evaluation uses the effective relative acceleration Δa and relative displacement ΔL corresponding to the stability data acquisition device to perform stability calculation, specifically, the received discrete Δa and ΔL data are curve fitted to obtain a Δa-ΔL curve, and the area of ​​the figure enclosed by the Δa-ΔL curve and the ΔL coordinate axis is calculated, thereby obtaining a local stability index S.

[0057] When the local stability calculation is completed through basic data, the stability of the train in what state and at what position on the line can be determined in combination with GPS time, GPS longitude and latitude, locomotive driving status data and electronic high-definition map. The quality of the train running stability is judged according to the different interval ranges of stability, wherein the larger the value of stability, the worse the train running stability. Preferably, the interval ranges are divided into three, and when the stability belongs to the three different interval ranges, the stability calculation evaluation unit judges the train running stability as "excellent", "medium" and "poor" respectively.

[0058] When performing overall stability calculation and evaluation, the data from several stability data acquisition devices are used, that is, after completing the local stability calculation and evaluation based on the data from each stability data acquisition device, when the stability of several devices is good, it means that the overall stability of the train is good; when the stability calculated and evaluated based on the data from a certain stability data acquisition device is not good, it is necessary to make a comprehensive judgment based on the stability corresponding to other stability data acquisition devices.

[0059] The present invention also provides a method for evaluating the running stability of a freight train, which is implemented by using the freight train running stability evaluation system. The method for evaluating the running stability of a freight train comprises: firstly, a number of stability data acquisition devices are arranged along the distribution of the vehicle, each of the stability data acquisition devices collects information such as time, longitude and latitude, longitudinal acceleration, lateral acceleration, vertical acceleration, pitch angle, roll angle, yaw angle and angular velocity around three axes, distance between cars, and coupler status; the above-collected information is passed to a data alignment unit for data alignment; the relevant data of the acceleration sensor is passed to a data preprocessing and true value calculation unit for data preprocessing and true value calculation to obtain the true values ​​of the longitudinal acceleration, lateral acceleration, vertical acceleration, pitch angle, roll angle, and yaw angle; the video of the driving recorder is passed to a free gap determination unit to determine the free gap C of the coupler; the video of the driving recorder and the distance between two adjacent cars collected by the laser sensor are passed to a distance correction unit to obtain the corrected distance between the two adjacent cars. The car spacing L between the front and rear cars is used to calculate the relative acceleration Δa, and the relative displacement ΔL is calculated using the corrected car spacing L between the two adjacent cars. The data validity is judged based on the relative acceleration Δa, the relative displacement ΔL and the free clearance state C of the coupler. Finally, the stability is calculated based on the effective relative acceleration Δa and the relative displacement ΔL. The received discrete Δa and ΔL data are curve fitted to obtain the Δa-ΔL curve, and the area of ​​the figure enclosed by the Δa-ΔL curve and the ΔL coordinate axis is calculated to obtain the local stability index S. The local stability is comprehensively calculated and evaluated based on the GPS time, GPS longitude and latitude, locomotive driving status data and electronic high-definition map. Finally, the overall stability is calculated and evaluated using several stability indices.

[0060] According to one embodiment of the present invention, the time and longitude and latitude are collected by the GPS device in the stability data collection device; the acceleration, angle and angular velocity are collected by the acceleration sensor; the distance between cars is collected by the laser sensor; and the free gap status of the coupler is collected by the driving recorder.

[0061] All data collected by the stationary data collection device of the present invention include time due to the GPS device.

[0062] In order to summarize and analyze the data collected by the stability data acquisition device, it is also necessary to use the data alignment unit to align the above-mentioned time data, namely: 1) align the data of each stability data acquisition device according to the time recorded by the GPS device, and obtain the data collected by a single stability data acquisition device at the same time; 2) align the corresponding data collected by multiple stability data acquisition devices according to the recorded GPS time; 3) align the data of the stability data acquisition device and the locomotive driving status data according to time, so as to facilitate the subsequent comprehensive stability evaluation; 4) align the data of the stability data acquisition device with the electronic high-definition map, which can display the geographical location of the current data, and can be matched with the specific mileage in the railway line data, so as to obtain the line parameters (including slope and curve) of the location.

[0063] In order to facilitate more accurate analysis of the data collected by the stability data acquisition device, it is also necessary to use the data preprocessing and true value calculation unit to preprocess the pitch angle, roll angle and yaw angle; considering that a part of the data already exists in the period from the time when the stability data acquisition device is installed in the freight train car to the time when the freight train departs, this part of the data should be subtracted and the true value calculated, so the longitudinal acceleration, lateral acceleration, vertical acceleration, pitch angle, roll angle and yaw angle are calculated for true values.

[0064] In order to facilitate a more comprehensive analysis of the data collected by the stability data acquisition device, the evaluation method also includes: transmitting the video of the driving recorder to the free gap judgment unit to judge the free gap state of the coupler, and the free gap state of the coupler is divided into a free state, a pressed hook state and a pulled hook state; transmitting the video of the driving recorder to the spacing correction unit, using the video processing algorithm to calculate the bending angle of the coupler, and then correcting the spacing L between the two adjacent carriages collected by the laser sensor; transmitting the longitudinal acceleration, lateral acceleration, vertical acceleration, pitch angle, roll angle, yaw angle and the corrected carriage spacing L between the front and rear carriages to the relative acceleration and relative displacement calculation unit to calculate the relative acceleration and relative displacement, and transmitting the relative acceleration Δa, relative displacement ΔL and the free gap state C of the coupler to the data validity judgment unit for validity judgment.

[0065] In order to use the above processed data to calculate and evaluate the stability, the above effective relative acceleration and relative displacement are transmitted to the stability calculation and evaluation unit for local stability calculation and evaluation. When the stability calculation is completed through the basic data, the locomotive driving status data and the electronic high-definition map can be combined to determine the stability of the train in what state and at what position on the line. The quality of the train running stability is judged according to the different intervals of stability, wherein the larger the value of stability, the worse the train running stability. Preferably, the interval ranges are divided into three, and when the stability belongs to the three different interval ranges, the stability calculation and evaluation unit judges the train running stability as "excellent", "medium" and "poor" respectively.

[0066] When performing overall stability calculation and evaluation, the data from several stability data acquisition devices are used, that is, after completing the local stability calculation and evaluation based on the data from each stability data acquisition device, when the stability of several devices is good, it means that the overall stability of the train is good; when the stability calculated and evaluated based on the data from a certain stability data acquisition device is not good, it is necessary to make a comprehensive judgment based on the stability corresponding to other stability data acquisition devices.

[0067] In order to facilitate the analysis of stability, the evaluation method also includes: drawing a table of acceleration data, corrected car spacing, angular velocity, coupler free gap, GPS time, GPS longitude and latitude, relative acceleration, relative displacement and calculated stability at each time point; drawing a graphical curve with acceleration data, corrected car spacing, angular velocity, coupler free gap and calculated stability as vertical coordinates and GPS time or line data (including mileage and line parameters) as horizontal coordinates; combining locomotive driving status data to display the locomotive driving status corresponding to the current stability, and displaying the current position in an electronic high-definition map; integrating the above information and using a ground comprehensive evaluation unit to automatically generate a stability report, laying the foundation for further subsequent research.

[0068] The above embodiments are provided to persons familiar with the art to implement or use the present invention. Personnel familiar with the art may make various modifications or changes to the above embodiments without departing from the inventive concept of the present invention, and these modifications or changes all fall within the protection scope of the present invention.

Claims

1. A freight train running stability assessment system, comprising a plurality of stability data acquisition devices distributed along the vehicle and a ground comprehensive assessment unit; The stability data acquisition device comprises: CPU board, acceleration sensor, laser sensor, GPS device, driving recorder, data acquisition status display module and power module; The acceleration sensor is used to collect the longitudinal acceleration, lateral acceleration, vertical acceleration, pitch angle, roll angle, yaw angle and angular velocity around three axes of the vehicle; The laser sensor is used to collect the distance between two adjacent carriages; the GPS device is used as a clock module to provide system time and collect the current time latitude and longitude; The CPU board communicates with the acceleration sensor, the laser sensor and the GPS device through a serial port; the driving recorder is used to record the state of the coupler between two adjacent carriages; The ground comprehensive evaluation unit exchanges data with the stability data acquisition device, and uses the data collected by the stability data acquisition device to perform calculation and evaluation of stability.

2. The freight train running stability assessment system according to claim 1, characterized in that: The ground comprehensive evaluation unit also exchanges data with the locomotive driving status acquisition equipment, and performs calculation and evaluation of stability in combination with the locomotive driving status data and the electronic high-definition map.

3. The freight train running stability assessment system according to claim 2, characterized in that: The ground comprehensive evaluation unit includes a data processing unit, a free gap state determination unit, a spacing correction unit, a relative acceleration and relative displacement calculation unit, a data validity judgment unit, and a stability calculation and evaluation unit; the data processing unit also includes a data alignment unit, a data preprocessing unit and a true value calculation unit.

4. The freight train running stability assessment system according to claim 3 is characterized in that: The data alignment unit aligns the data collected by a single stability data acquisition device, aligns the corresponding data collected by multiple stability data acquisition devices, and aligns the data of the stability data acquisition device with the locomotive driving status data according to the time provided by the GPS device; at the same time, the data of the stability data acquisition device is aligned with the electronic high-definition map according to the time and longitude and latitude provided by the GPS device, so that the geographical location of the current data can be displayed, and it can be matched with the specific mileage in the railway line data to obtain the line parameters of the location.

5. The freight train running stability assessment system according to claim 3 is characterized in that: The data preprocessing and true value calculation unit performs data preprocessing on the pitch angle, the roll angle and the yaw angle, and performs true value calculation on the longitudinal acceleration, the lateral acceleration, the vertical acceleration, the pitch angle, the roll angle and the yaw angle.

6. The freight train running stability assessment system according to claim 5, characterized in that: The free gap state determination unit is used to analyze the image recorded by the driving recorder, so as to determine the free gap state of the coupler. The free gap state of the coupler is divided into a free state, a pressed hook state and a pulled hook state.

7. The freight train running stability assessment system according to claim 6, characterized in that: The spacing correction unit uses a video processing algorithm to analyze the image recorded by the driving recorder, calculates the current coupler bending angle, and then corrects the spacing between two adjacent carriages collected by the laser sensor.

8. The freight train running stability assessment system according to claim 7, characterized in that: The relative acceleration and relative displacement calculation unit calculates the relative acceleration using the longitudinal acceleration, lateral acceleration, vertical acceleration, pitch angle, roll angle and yaw angle between the front and rear carriages, and calculates the relative displacement using the corrected carriage spacing between the two adjacent carriages. The data validity judgment unit receives the relative acceleration Δa, relative displacement ΔL and the free clearance state C of the coupler to judge the data validity.

9. The freight train running stability assessment system according to claim 8, characterized in that: The stability calculation and evaluation unit performs calculation and evaluation of local stability and overall stability; the local stability calculation and evaluation utilizes relative acceleration and relative displacement to perform stability calculation, and combines locomotive driving status data and electronic high-definition maps to determine the stability index of the train in what state and at what position on the line; the overall stability calculation and evaluation utilizes data from the plurality of stability data acquisition devices, that is, after completing the local stability calculation and evaluation, a comprehensive judgment is made based on the stability index corresponding to each stability data acquisition device.

10. A method for evaluating the running stability of a freight train using the evaluation system according to any one of claims 1 to 9, the method comprising: Several stability data collection devices are arranged along the vehicle, each of which collects information such as time, longitude and latitude, longitudinal acceleration, lateral acceleration, vertical acceleration, pitch angle, roll angle, yaw angle and angular velocity around three axes, distance between carriages, and coupler status; Perform data alignment on the above collected information; The relevant data of the acceleration sensor are preprocessed and the true value is calculated to obtain the true values ​​of the longitudinal acceleration, lateral acceleration, vertical acceleration, pitch angle, roll angle and yaw angle; the free gap state of the coupler is determined based on the video of the driving recorder; the distance between the two adjacent carriages collected by the laser sensor is corrected based on the video of the driving recorder; the relative acceleration is calculated based on the longitudinal acceleration, lateral acceleration, vertical acceleration, pitch angle, roll angle and yaw angle between the front and rear carriages, and the relative displacement is calculated based on the corrected carriage distance between the two adjacent carriages; the data validity is judged based on the relative acceleration, relative displacement and the free gap state of the coupler, and finally the stability index is calculated based on the effective relative acceleration and relative displacement.

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