A speed measurement method, device and system

Abstract

The present invention discloses a speed measurement method, device and system, which relate to the field of speed measurement. At the beginning of a cycle, a first pulse signal and a second pulse signal sent by multiple train OPGs are obtained within the cycle, and it is determined whether the frequency difference between the frequency of the first pulse signal and the frequency of the second pulse signal obtained at the same time is greater than a preset difference. If it is greater, the two pulse signals are deleted, and if it is not greater, only the first pulse signal is retained. At the end of the current cycle, the average speed and driving direction of the train in the current cycle are determined according to all the remaining first pulse signals, and finally the determined average speed and driving direction are sent to a host computer. Since the calculation result sent to the host computer is the final and only result, the host computer does not need to participate in the comparison again, and the underlying logic of the host computer does not need to be modified to reduce the implementation complexity and improve the availability. In addition, setting a time interval in each cycle to obtain a pulse signal can ensure the real-time performance of the speed measurement.

Description

Technical Field

[0001] The present invention relates to the field of speed measurement, and in particular to a speed measurement method, device and system. Background Art

[0002] When a train is running, it is necessary to detect the speed and direction of the train in real time, and evaluate whether the running state of the train is safe based on the real-time speed and direction. Since the detection results of speed and direction are directly related to the evaluation results of driving safety, high real-time performance and safety are required. In the prior art, the real-time speed and direction of the train are calculated by collecting the pulse signal of the train's OPG (Odometer PulseGenerator, speed measuring motor). The OPG will output two pulse signals, collect the two pulse signals respectively and calculate them, and obtain two real-time speed and direction calculation results. Finally, the two calculation results are sent to the host computer for comparison to obtain the final result.

[0003] However, according to the current SIL (Safety Integrity Level) regulations for trains, the SIL level related to speed measurement is level 4. Under this SIL level, the two calculation results need to be completely consistent before the calculation results can be sent to the host computer. Because the two calculation results are inconsistent, the underlying logic of the host computer needs to be modified to achieve the purpose of sending the two inconsistent calculation results to the host computer, which increases the implementation complexity and reduces the availability. In addition, since the pulse frequency of the OPG is higher than the operating frequency of the host computer, it is difficult to meet the real-time requirements through the comparison of the host computer. Summary of the invention

[0004] The purpose of the present invention is to provide a speed measurement method, device and system, which do not require the host computer to participate in comparison and calculation, and thus do not need to modify the underlying logic of the host computer, thereby reducing the implementation complexity and improving usability, and can also ensure the real-time performance of the speed measurement.

[0005] In order to solve the above technical problems, the present invention provides a speed measurement method, which is applied to a processor on a train, and the processor is respectively connected to a host computer of the train and an OPG of the train. The speed measurement method includes:

[0006] At the beginning of the current cycle, the first pulse signal and the second pulse signal sent by the OPG are obtained N times according to a preset time interval, where N is a positive integer not less than 2, and the preset time interval is not greater than the duration of the current cycle;

[0007] Determine whether a frequency difference between the frequency of the first pulse signal and the frequency of the second pulse signal acquired at the same time is greater than a preset difference;

[0008] If it is greater than a preset difference, deleting the first pulse signal and the second pulse signal;

[0009] If it is not greater than the preset difference, retaining the first pulse signal and deleting the second pulse signal;

[0010] At the end of the current cycle, determining the average speed and travel direction of the train in the current cycle according to all the remaining first pulse signals;

[0011] Sending the average speed and the driving direction to the host computer;

[0012] The cycle is consistent with the working cycle of the host computer.

[0013] Preferably, after acquiring the first pulse signal and the second pulse signal sent by the OPG N times according to a preset time interval, the method further includes:

[0014] Determining the total number of the first pulse signals and the second pulse signals acquired within a preset duration of the current cycle;

[0015] Determine the total duration of obtaining N first pulse signals and the second pulse signals;

[0016] Determining the average speed and travel direction of the train in the current cycle according to all remaining first pulse signals includes:

[0017] The average speed and travel direction of the train in the current cycle are determined based on the total number, the total duration and all remaining first pulse signals.

[0018] Preferably, when the current cycle is not the first cycle after the train starts, determining the average speed and driving direction of the train in the current cycle according to the total number, the total duration and all the remaining first pulse signals includes:

[0019] Determining whether the average speed determined in a previous cycle of the current cycle is lower than a preset speed;

[0020] If it is lower than the preset speed, determining the average speed according to the total duration and all the remaining first pulse signals;

[0021] If it is not lower than the preset speed, the average speed is determined according to the total number and all the remaining first pulse signals.

[0022] Preferably, determining the average speed according to the total number, the total duration and all remaining first pulse signals includes:

[0023] Determine a first average speed according to the total number and all remaining first pulse signals;

[0024] Determine a second average speed according to the total duration and all remaining first pulse signals;

[0025] Determining whether a speed difference between the first average speed and the second average speed is greater than a preset speed;

[0026] If it is not greater than the preset speed, the designated average speed among the first average speed and the second average speed will be used as the average speed of the train in the current cycle.

[0027] Preferably, before determining whether the speed difference between the first average speed and the second average speed is greater than a preset speed, the method further includes:

[0028] Determining whether the first average speed is within a preset first average speed range and determining whether the second average speed is within a preset second average speed range;

[0029] If the first average speed is within the preset first average speed range and the second average speed is not within the preset second average speed range, taking the first average speed as the average speed;

[0030] If the first average speed is not within the preset first average speed range and the second average speed is within the preset second average speed range, taking the second average speed as the average speed;

[0031] If the first average speed is within the preset first average speed range and the second average speed is within the preset second average speed range, the process proceeds to a step of determining whether a speed difference between the first average speed and the second average speed is greater than a preset speed.

[0032] Preferably, before determining the average speed and travel direction of the train in the current cycle according to all the remaining first pulse signals, the method further includes:

[0033] Determine whether the user instruction is obtained;

[0034] If not obtained, the step of determining the average speed and travel direction of the train in the current cycle based on all the remaining first pulse signals is entered.

[0035] Preferably, determining the traveling direction of the train in the current cycle according to all remaining first pulse signals includes:

[0036] For any remaining first pulse signal, determining a front-to-back order between the first channel signal and the second channel signal in the first pulse signal;

[0037] Determine the train direction indicated by the first pulse signal according to the front-to-back sequence;

[0038] The traveling direction of the train in the current cycle is determined according to the train directions represented by all the remaining first pulse signals.

[0039] Preferably, after determining the train direction represented by the first pulse signal according to the phase difference, the method further includes:

[0040] Determining whether the directions of the trains are consistent;

[0041] If so, the step of determining the travel direction of the train in the current cycle based on the train directions represented by all the remaining first pulse signals is entered.

[0042] The present application also provides a speed measuring device, comprising:

[0043] Memory for storing computer programs;

[0044] A processor is used to implement the steps of the speed measurement method as described above when executing the computer program.

[0045] The present application also provides a speed measurement system, including a host computer and an OPG, and also including a speed measurement device as described above;

[0046] The speed measuring device is connected to the host computer and the OPG respectively.

[0047] In summary, the present application provides a speed measurement method, device and system, which relates to the field of speed measurement, and is applied to a processor on a train. The processor is connected to the upper computer and OPG of the train respectively. At the beginning of a cycle, the first pulse signal and the second pulse signal sent by the OPG are obtained multiple times within the cycle, and it is determined whether the frequency difference between the frequency of the first pulse signal and the frequency of the second pulse signal obtained at the same time is greater than the preset difference. If it is greater, the two pulse signals are deleted, and if it is not greater, only the first pulse signal is retained. At the end of the current cycle, the average speed and driving direction of the train in the current cycle are determined according to all the remaining first pulse signals, and finally the determined average speed and driving direction are sent to the upper computer, wherein the above cycle is consistent with the working cycle of the upper computer. By comparing the pulse signals, and deleting the corresponding pulse signals according to the comparison results, the calculation results of the speed and direction are directly calculated according to the remaining pulse signals, and the calculation results sent to the upper computer are the final unique results, and the upper computer does not need to participate in the comparison and calculation, and thus there is no need to modify the underlying logic of the upper computer, which reduces the implementation complexity and improves the usability. In addition, by synchronizing the speed measurement cycle with the working cycle of the host computer and collecting pulses multiple times in one speed measurement cycle to calculate the average speed of the cycle, the real-time speed measurement can be guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the prior art and the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0049] Figure 1 A flow chart of a speed measurement method provided for this application;

[0050] Figure 2 A schematic diagram of a data frame provided for this application;

[0051] Figure 3 A schematic diagram of the structure of a speed measuring device provided in this application;

[0052] Figure 4 A schematic diagram of the structure of a speed measurement system provided in this application;

[0053] Figure 5 A schematic diagram of the structure of another speed measurement system provided in this application. DETAILED DESCRIPTION

[0054] The core of the present invention is to provide a speed measurement method, device and system, which does not require the host computer to participate in comparison and calculation, and thus does not need to modify the underlying logic of the host computer, thereby reducing the implementation complexity and improving usability, and can also ensure the real-time performance of the speed measurement.

[0055] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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 creative work are within the scope of protection of the present invention.

[0056] In order to detect the speed and displacement of the train, currently, a special speed and distance measuring device, namely OPG, is usually configured to measure the speed, displacement and other information of the train in real time. Since OPG is a SIL4 level device, compared with other levels of equipment, the standard safety platform architecture cannot be applied. Specifically, since OPG will output two pulse signals, in order to ensure the accuracy of the train speed measurement, both pulse signals need to be calculated to obtain the final speed measurement result. However, due to certain differences between the pulse signals output by OPG, the speed measurement results of the two pulse signals will be different. In the standard safety platform architecture, it is required to obtain two completely consistent speed measurement results before the speed measurement results can be sent to the host computer for subsequent steps. It can be seen that there is a conflict between the two. In order to avoid this conflict, the existing technology needs to use a specially processed host computer or modify the underlying logic of the host computer so that the host computer can normally receive the two different speed measurement results. However, this method is not suitable for promotion and has poor practicality.

[0057] To solve the above technical problems, please refer to Figure 1 , Figure 1 A flow chart of a speed measurement method provided in the present application is applied to a processor on a train, the processor is respectively connected to a host computer of the train and an OPG of the train, and the speed measurement method includes:

[0058] S1: At the beginning of the current cycle, the first pulse signal and the second pulse signal sent by the OPG are obtained N times according to a preset time interval, where N is a positive integer not less than 2, and the preset time interval is not greater than the duration of the current cycle;

[0059] Taking into account the different working cycles of the host computer and OPG, the period of OPG's pulse collection is much shorter than that of the host computer, which may cause the host computer to fail to obtain most of the pulse signals. Therefore, the present application sets a calculation cycle, the length of which is consistent with the length of the working cycle of the host computer, and in each calculation cycle, a preset time interval is used as a small pulse collection period. The time interval can be set shorter to meet the real-time requirements of the train speed measurement, which is equivalent to setting a long period to synchronize the working cycle of the host computer, and setting a short period to achieve real-time speed measurement.

[0060] S2: Determine whether the frequency difference between the frequency of the first pulse signal and the frequency of the second pulse signal obtained at the same time is greater than a preset difference;

[0061] S3: If the difference is greater than a preset value, the first pulse signal and the second pulse signal are deleted;

[0062] S4: If it is not greater than the preset difference, retain the first pulse signal and delete the second pulse signal;

[0063] Each time a pulse signal is obtained, because the OPG will output two pulse signals, and there may be some errors between the two pulse signals, resulting in errors in the speed measurement results calculated by the two pulse signals, and the error is the reason why the host computer cannot receive the speed measurement results, so the error needs to be eliminated. Specifically, for two pulse signals obtained at the same time, it is necessary to compare whether the difference between the two pulse signals is too large, that is, to determine whether the difference between the frequencies of the two pulse signals is too large, or it can also be determined whether the difference between the characteristics such as pulse period or amplitude is too large.

[0064] Ideally, after OPG detects the train speed, it will output two completely identical pulse signals; in reality, although there are differences between the two pulse signals, the differences are usually within an acceptable range; if there are short-term sudden situations such as interference and failure, the difference between the two pulse signals may be too large. Based on this, when the difference between the two pulse signals is within an acceptable range, it means that the two pulse signals are approximately equal, and the speed measurement results calculated in the end are also approximately equal. Under the premise of ensuring the accuracy of the calculation results, in order to eliminate the difference in the pulse signals, one of the two pulse signals is deleted; when the difference between the two pulse signals is too large, since the pulse signal at this time is generated under short-term sudden conditions, it has no reference to the actual speed of the train. Therefore, in order to ensure the accuracy of the calculation results, both pulse signals are directly deleted.

[0065] S5: at the end of the current cycle, determining the average speed and travel direction of the train in the current cycle according to all remaining first pulse signals;

[0066] S6: Send the average speed and driving direction to the host computer;

[0067] In the current cycle, no matter the pulse signal is deleted because the difference between the two pulse signals is too large or within an acceptable range, the remaining pulse signals are all first pulse signals, that is, the remaining pulse signals are all pulse signals output from the same path. The average speed and driving direction of the train are determined based on the pulse signals of this path, and a unique speed measurement result is obtained. Specifically, for the average speed, the instantaneous speed of each first pulse signal at the time of generation can be calculated based on the frequency of each first pulse signal, and then the average speed can be calculated based on these instantaneous speeds; for the driving direction, it can be determined based on the phase difference between the pulse signals.

[0068] Compared with the prior art that outputs two-way speed measurement results, the present application takes into account that the speed result may have a certain error acceptance range, calculates a unique speed measurement result within the error acceptance range, and finally sends the unique speed measurement result to the host computer without modifying the underlying logic of the host computer or using a specially processed host computer.

[0069] Among them, the cycle is consistent with the working cycle of the host computer.

[0070] In summary, the processor is connected to the host computer and OPG of the train respectively. At the beginning of the cycle, the first pulse signal and the second pulse signal sent by OPG are obtained multiple times within the cycle. It is determined whether the frequency difference between the frequency of the first pulse signal and the frequency of the second pulse signal obtained at the same time is greater than the preset difference. If it is greater, the two pulse signals are deleted. If it is not greater, only the first pulse signal is retained. At the end of the current cycle, the average speed and driving direction of the train in the current cycle are determined according to all the remaining first pulse signals. Finally, the determined average speed and driving direction are sent to the host computer, wherein the above cycle is consistent with the working cycle of the host computer. By comparing the pulse signals, and deleting the corresponding pulse signals according to the comparison results, the calculation results of the speed and direction are directly calculated according to the remaining pulse signals, and the calculation results sent to the host computer are the final and only results. The host computer does not need to participate in the comparison and calculation, and thus does not need to modify the underlying logic of the host computer, which reduces the implementation complexity and improves the availability. In addition, by synchronizing the speed measurement cycle with the working cycle of the host computer, and collecting pulses multiple times in a speed measurement cycle to calculate the average speed of the cycle, the real-time speed measurement can be guaranteed.

[0071] Based on the above embodiments:

[0072] As a preferred embodiment, after acquiring the first pulse signal and the second pulse signal sent by the OPG N times according to the preset time interval, the method further includes:

[0073] Determine the total number of first pulse signals and second pulse signals acquired within a preset duration of a current cycle;

[0074] Determine the total duration of the N first pulse signals and the second pulse signals obtained;

[0075] The average speed and travel direction of the train in the current cycle are determined according to all remaining first pulse signals, including:

[0076] The average speed and travel direction of the train in the current cycle are determined based on the total number, the total duration and all the remaining first pulse signals.

[0077] In order to accurately determine the speed and direction of the train, in this application, it is considered that when acquiring the pulse signal sent by the OPG, not all the pulse signals sent by the OPG in the current cycle are acquired, but some of the pulse signals are acquired for calculation. In an ideal situation, the OPG will generate a pulse signal according to a preset time interval so that the processor can acquire the pulse signal. However, in actual situations, the time when the OPG generates a pulse signal will be affected by the actual speed of the train. The faster the train speed, the shorter the interval between the OPG generating the pulse signal, resulting in a certain error between the actual time when the processor executes to acquire the pulse signal and the preset time interval. For example, assuming that the preset time interval is 5ms, in actual situations, the OPG generates a pulse signal when it reaches 4.9ms, and the next time it may be generated after another 5.3ms, which causes the actual time when the processor acquires the pulse signal to change. Therefore, it is necessary to know the actual time when the pulse signal is acquired in order to correct the average speed according to the actual time.

[0078] Specifically, a preset duration can be set in advance, and the preset duration is also smaller than the duration of the large cycle, and also needs to be smaller than the theoretical total duration for obtaining N pulse signals. This is because when the preset duration is greater than the theoretical total duration, the total number of pulse signals obtained within the preset duration of any time length is always consistent, and there is no reference for subsequent steps. In practical applications, the total number of pulse signals obtained within the preset duration is determined, and compared with the total number that can be obtained theoretically within the preset duration. It can be seen that if the total number of pulse signals is greater than the total number that can be obtained theoretically, it means that the current actual speed of the train is relatively fast; on the contrary, if the total number of pulse signals is less than the total number that can be obtained theoretically, it means that the current actual speed of the train is relatively slow, and the final average speed can be corrected based on this. For example, the current cycle is 100ms. OPG theoretically generates a pulse signal every 5ms. N is 10, and the preset duration can be set to 30ms. It can be seen that theoretically a maximum of 7 pulse signals can be obtained within 30ms. However, in actual situations, OPG may generate a pulse signal after 4ms or 6ms, resulting in the actual pulse signal being not equal to 7.

[0079] Similarly, after obtaining N pulse signals, the difference between the actual total duration and the theoretical total duration is determined. If the actual total duration is shorter than the theoretical total duration, the actual speed of the train is faster; otherwise, the actual speed of the train is slower. Based on this, the final average speed is corrected.

[0080] For example, the step of calculating the total number can be called mode 1, and the step of calculating the total duration can be called mode 2. The system layer can send an interrupt signal ISR1 to mode 1 at intervals as its clock signal; the underlying driver layer provides a clock signal ISR2 to mode 2 so that it can calculate the actual total duration; in addition, the underlying driver layer generates an interrupt signal ISR3 as a collection signal, and the data collection of mode 1 is completed through the cooperation of ISR1 and ISR3. The data collection of mode 2 is completed through the cooperation of ISR2 and ISR3. As for the driving direction, ISR1 updates the mode 1 data. When it is found that the total number calculated by mode 1 does not meet the expectations, the step of mode 1 is reset, or the mode 1 data in this cycle is deleted. In addition, at regular intervals, the ISR3 interrupt is enabled through ISR1 to update the direction data collected by the pulse.

[0081] Based on this, by introducing the actual time taken to obtain N pulse signals and the number of pulse signals obtained within a preset time length, the speed and direction of the train can be accurately determined.

[0082] As a preferred embodiment, when the current cycle is not the first cycle after the train starts, the average speed is determined according to the total number, the total duration and all the remaining first pulse signals, including:

[0083] Determine whether the average speed determined in the previous cycle of the current cycle is lower than the preset speed;

[0084] If it is lower than the preset speed, the average speed is determined according to the total duration and all remaining first pulse signals;

[0085] If it is not lower than the preset speed, the average speed is determined according to the total number and all the remaining first pulse signals.

[0086] In order to accurately determine the speed of the train, in this application, considering that the current actual speed of the train will affect the pulse signal of the OPG, when the actual speed of the train is too slow, the pulse signal generated in the current cycle may be less, which may cause the total number of pulse signals obtained within the preset time to be too small, or even 1 or 0, resulting in the total number having an abnormal effect on the calculation of the train speed. In order to accurately determine the speed of the train, the total number can be ignored, and the average speed can be determined only by the total time and all the remaining first pulse signals; when the actual speed of the train is normal, considering that the difference between the total time spent to obtain N pulse signals is not large, in order to reduce the calculation pressure, the total time can be ignored, and the average speed can be determined only by the total number and all the remaining first pulse signals. For the actual speed of the train, the average speed calculated in the previous cycle is used. Since the working cycle of the host computer is usually at the ms level, the actual speed of the train between adjacent cycles does not change much, so the average speed of the previous cycle can be used as the actual speed of the train in this cycle. The preset speed can be set according to the time that the OPG can generate pulse signals within the acceptable time interval when the train is running normally. When the actual speed of the train is greater than the preset speed, the OPG can normally generate at least N pulse signals in the current cycle. Based on this, the train speed can be accurately determined.

[0087] As a preferred embodiment, determining the average speed according to the total number, the total duration and all remaining first pulse signals includes:

[0088] Determine a first average speed according to the total number and all remaining first pulse signals;

[0089] Determine a second average speed according to the total duration and all remaining first pulse signals;

[0090] Determining whether a speed difference between the first average speed and the second average speed is greater than a preset speed;

[0091] If it is not greater than the preset speed, the specified average speed in the first average speed and the second average speed will be used as the average speed of the train in the current cycle.

[0092] In order to accurately determine the speed of the train, in this application, in order to avoid the calculation of one of the total number and the total duration causing an abnormality in the calculated total number or total duration due to some short-term emergencies, firstly, the corresponding average speeds are calculated according to the total duration / total number and the first pulse signal. It can be understood that since the speed of the train is the only parameter, under normal circumstances, the calculated first average speed and the second average speed will be close to the actual speed of the train. It can be known that the first average speed and the second average speed are also close. Based on this, after calculating the two average speeds, it is determined whether the difference between the two average speeds is too large. If it is too large, it means that at least one of the two average speeds A is abnormal, and the other average speed B has lost the other average speed A as a reference, so it is unknown whether the other average speed B is a normal speed. At this time, in order to ensure the accuracy of the train speed measurement, the calculation results of this cycle can be directly invalidated, and the next round of calculations can be performed after the next cycle starts; only when the difference between the first average speed and the second average speed is within an acceptable range, any of the two average speeds can be used as the final speed measurement result according to the needs of the staff. Please refer to Figure 2 , Figure 2 A schematic diagram of a data frame provided by the present application, the step of calculating the first average speed can be called model1, and the step of calculating the second average speed can be called model2, which is equivalent to corresponding to mode 1 and mode 2 in the above embodiment. During the calculation process, the number of pulse signals and the corresponding calculation results (BUFF) determined by model1 and model2 are first determined, and the respective speed measurement results are calculated according to the cycle configuration and pulse configuration specified by the current user. Based on this, the train speed can be accurately determined.

[0093] As a preferred embodiment, before determining whether the speed difference between the first average speed and the second average speed is greater than a preset speed, the method further includes:

[0094] Determining whether the first average speed is within a preset first average speed range and determining whether the second average speed is within a preset second average speed range;

[0095] If the first average speed is within the preset first average speed range and the second average speed is not within the preset second average speed range, the first average speed is used as the average speed;

[0096] If the first average speed is not within the preset first average speed range and the second average speed is within the preset second average speed range, the second average speed is used as the average speed;

[0097] If the first average speed is within the preset first average speed range and the second average speed is within the preset second average speed range, the process proceeds to a step of determining whether a speed difference between the first average speed and the second average speed is greater than a preset speed.

[0098] In order to accurately determine the speed of the train, in this application, it is considered that in actual situations, both average speeds may be abnormal, but the difference between the two average speeds after the abnormality is not large. Therefore, before comparing the speed difference between the two average speeds, it is also necessary to compare the two average speeds with their corresponding preset average speed ranges. The preset first / second average speed range is calculated based on the normal running speed of the train history. The two preset average speed ranges can be different ranges but with a small difference, or they can be the same speed range. If the first or second average speed is not within the corresponding preset average speed range, it can be directly determined to be abnormal, and another normal average speed can be used as the final speed measurement result; if both average speeds are normal, the subsequent process of determining the speed difference is entered; if both average speeds are abnormal, both average speeds are deleted, that is, the current cycle is invalidated, and a new round of calculations will start after the next cycle begins. Based on this, the train speed can be accurately determined.

[0099] As a preferred embodiment, before determining the average speed and driving direction of the train in the current cycle according to all the remaining first pulse signals, the method further includes:

[0100] Determine whether the user instruction is obtained;

[0101] If not obtained, the step of determining the average speed and travel direction of the train in the current cycle based on all remaining first pulse signals is entered.

[0102] In order to synchronize the new speed measurement process in time, in this application, it is taken into account that in actual situations, the specific speed measurement steps may change due to factors such as train speed, climate, railway conditions, and the OPG model actually used. For example, when obtaining the first pulse signal and the second pulse signal sent by the OPG N times, the actual value of N may change; or when judging whether the frequency difference between the two pulse signals is greater than the preset difference, the actual preset difference may also change, etc. When such a change occurs, it means that the subsequent speed measurement process needs to be calculated based on the changed parameters such as the new N value or the new preset difference. Therefore, the user generates a corresponding user instruction by operating the user terminal and sends it to the processor. When the processor receives the user instruction, it can be determined that there is a parameter change, and the speed measurement result calculated in the current cycle is not applicable to the new speed measurement process; if there is no user instruction, it means that there is no parameter change, and the processor executes the subsequent steps normally. Based on this, the new speed measurement process can be synchronized in time.

[0103] As a preferred embodiment, determining the travel direction of the train in the current cycle according to all remaining first pulse signals includes:

[0104] For any remaining first pulse signal, determining a front-to-back sequence between the first channel signal and the second channel signal in the first pulse signal;

[0105] Determine the train direction indicated by the first pulse signal according to the front-to-back sequence;

[0106] The traveling direction of the train in the current cycle is determined according to the train directions indicated by all the remaining first pulse signals.

[0107] In order to simply determine the direction of travel of the train, in this application, since the pulse signal generated by the OPG belongs to a dual-channel signal, that is, each pulse signal is actually composed of sub-pulse signals of two channels, the direction of travel of the train can be determined by first determining the phase difference between the two sub-pulse signals (that is, channel signals) in the same pulse signal, and then by the phase difference according to the order of the channel signals. For example, it can be predetermined that the first channel signal is a signal indicating travel in the direction of the front of the train, and the second channel signal is a signal indicating travel in the direction of the rear of the train. When the phase difference between the first channel signal and the second channel signal is 90 degrees, the gap between the two channel signals is 1 / 4 cycle. If the first channel signal is in front and the second channel signal is in the back, such as when the level of the second channel signal just flips from 0 to 1, the first channel signal is already 1, then it can be said that the first channel signal is in front and the second channel signal is in the back, and then it can be said that the direction of travel of the train is the direction of the front of the train; on the contrary, if the second channel signal is in front, it can be said that the direction of travel of the train is the direction of the rear of the train. Based on this, by determining the train direction corresponding to each pulse signal, the direction of travel of the train can be determined.

[0108] As a preferred embodiment, after determining the train direction represented by the first pulse signal according to the phase difference, the method further includes:

[0109] Determine whether the directions of all trains are consistent;

[0110] If so, the step of determining the travel direction of the train in the current cycle according to the train directions represented by all the remaining first pulse signals is entered.

[0111] In order to accurately determine the direction of travel of the train, in this application, it is taken into account that the working cycle of the upper computer is usually tens of ms or hundreds of ms, that is, the time of the current cycle is usually tens of ms or hundreds of ms. When the train is running normally, due to the high speed of the train and the heavy total weight of the train, the train has a large inertia. It is understandable that under normal circumstances, it is impossible for the train to suddenly change its direction from the front direction to the rear direction within tens of ms or hundreds of ms, that is, within one cycle. Therefore, if there are inconsistent train directions among the train directions detected within one cycle, it means that there is a problem with the direction calculation of the current cycle, which needs to be recalculated or invalidated; only when all train directions detected within one cycle are expressed as the same direction can the subsequent steps be performed.

[0112] Please refer to Figure 3 , Figure 3 A schematic structural diagram of a speed measuring device provided for this application includes:

[0113] A memory 21, used for storing computer programs;

[0114] The processor 22 is used to implement the steps of the speed measurement method as described above when executing a computer program.

[0115] For a detailed introduction to a speed measuring device provided in the present application, please refer to the above-mentioned embodiment of the speed measuring method, and the present application will not go into details here.

[0116] Please refer to Figure 4 , Figure 4 A schematic diagram of the structure of a speed measurement system provided in the present application, including a host computer 31 and an OPG 33, and also including a speed measurement device 32 as described above;

[0117] The speed measuring device 32 is connected to the host computer 31 and the OPG 33 respectively.

[0118] For a detailed introduction to a speed measurement system provided in the present application, please refer to the above-mentioned embodiment of the speed measurement method, and the present application will not go into details here.

[0119] Considering that some security computer platforms have two host computers 31, both host computers 31 need to obtain the speed measurement results from the speed measurement device 32. Therefore, in order to avoid common mode failure, please refer to Figure 5 , Figure 5A structural diagram of another speed measuring system provided for the present application can be provided with two CPUs of different models as speed measuring devices 32, and the two speed measuring devices respectively obtain pulse signals of different OPG33s, and forward the original pulse signals obtained by themselves to the other speed measuring device 32 by connecting the two speed measuring devices 32 to each other, thereby achieving the purpose that both speed measuring devices 32 obtain two pulse signals, and the two speed measuring devices 32 are respectively connected to different host computers 31 to send their respective speed measurement results to the corresponding host computers 31, wherein, since the speed measurement processes of the two speed measuring devices 32 are completely consistent, the pulse signals obtained are also completely consistent, and therefore the calculated speed measurement results are also completely consistent, thereby achieving the purpose that both host computers 31 obtain the same speed measurement results. As for the speed measuring device 32 used specifically, different processors need to be used to avoid common mode failures between processors. For example, the speed measuring device 32 used for the first pulse signal (signal 1+signal 2) is a processor of TMS570, and the speed measuring device 32 used for the second pulse signal (signal 3+signal 4) is a processor of SCP5777. The two processors communicate with each other serially via the SPI bus, so that after calculating the speed measurement results, the two processors can verify each other to determine whether the speed measurement results calculated by each other are consistent, so as to output them to the host computer 31 when they are consistent; the pulse acquisition circuit therein is HCPL-0630, which is an optocoupler isolation chip and can be used with only an external power supply; the pulse signal output by OPG33 stabilizes the current at 10mA through the shunt circuit in the pulse acquisition circuit, which can achieve the best driving effect of the optocoupler, and the pulse signal voltage at the output end of the optocoupler is reduced from 5V to 2.5V through the voltage divider circuit and then input into the corresponding processor. Furthermore, when calculating the average speed and direction of travel, the two processors respectively calculate the speed, displacement and direction information of this cycle based on the collected pulse signals and the collection configuration specified by the user, and supervise the calculated displacement information and speed to judge the idling and slipping state and the stationary state of the train (for example, when the detected speed is very fast but the train has no displacement, it means that the train is idling), and finally generate a train motion information package to send to the upper computer 31 for processing. The train motion information package includes the speed measurement results of the two pulse signals, the parameter information of the channel pulse signals in the two pulses and the train travel direction, as well as the judgment results of the idling and slipping state and the stationary state.

[0120] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0121] It should also be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0122] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A speed measurement method, characterized in that: A processor applied to a train, the processor being connected to a host computer of the train and an OPG of the train respectively, the speed measurement method comprising: At the beginning of the current cycle, the first pulse signal and the second pulse signal sent by the OPG are obtained N times according to a preset time interval, where N is a positive integer not less than 2, and the preset time interval is not greater than the duration of the current cycle; Determine whether a frequency difference between the frequency of the first pulse signal and the frequency of the second pulse signal acquired at the same time is greater than a preset difference; If it is greater than a preset difference, deleting the first pulse signal and the second pulse signal; If it is not greater than the preset difference, retaining the first pulse signal and deleting the second pulse signal; At the end of the current cycle, determining the average speed and travel direction of the train in the current cycle according to all the remaining first pulse signals; Sending the average speed and the driving direction to the host computer; The cycle is consistent with the working cycle of the host computer.

2. The speed measurement method according to claim 1, characterized in that: After acquiring the first pulse signal and the second pulse signal sent by the OPG N times according to the preset time interval, the method further includes: Determining the total number of the first pulse signals and the second pulse signals acquired within a preset duration of the current cycle; Determine the total duration of obtaining N first pulse signals and the second pulse signals; Determining the average speed and travel direction of the train in the current cycle according to all remaining first pulse signals includes: The average speed and travel direction of the train in the current cycle are determined based on the total number, the total duration and all remaining first pulse signals.

3. The speed measurement method according to claim 2, characterized in that: When the current cycle is not the first cycle after the train is started, determining the average speed and driving direction of the train in the current cycle according to the total number, the total duration, and all remaining first pulse signals, including: Determining whether the average speed determined in a previous cycle of the current cycle is lower than a preset speed; If it is lower than the preset speed, determining the average speed according to the total duration and all the remaining first pulse signals; If it is not lower than the preset speed, the average speed is determined according to the total number and all the remaining first pulse signals.

4. The speed measurement method according to claim 2, characterized in that: Determining the average speed according to the total number, the total duration, and all remaining first pulse signals includes: Determine a first average speed according to the total number and all remaining first pulse signals; Determine a second average speed according to the total duration and all remaining first pulse signals; Determining whether a speed difference between the first average speed and the second average speed is greater than a preset speed; If it is not greater than the preset speed, the designated average speed among the first average speed and the second average speed is used as the average speed of the train in the current cycle.

5. The speed measurement method according to claim 4, characterized in that: Before determining whether the speed difference between the first average speed and the second average speed is greater than a preset speed, the method further includes: determining whether the first average speed is within a preset first average speed range and determining whether the second average speed is within a preset second average speed range; If the first average speed is within the preset first average speed range and the second average speed is not within the preset second average speed range, taking the first average speed as the average speed; If the first average speed is not within the preset first average speed range and the second average speed is within the preset second average speed range, taking the second average speed as the average speed; If the first average speed is within the preset first average speed range and the second average speed is within the preset second average speed range, the process proceeds to a step of determining whether a speed difference between the first average speed and the second average speed is greater than a preset speed.

6. The speed measurement method according to claim 1, characterized in that: Before determining the average speed and travel direction of the train in the current cycle according to all the remaining first pulse signals, the method further includes: Determine whether the user instruction is obtained; If not obtained, the step of determining the average speed and travel direction of the train in the current cycle based on all the remaining first pulse signals is entered.

7. The speed measurement method according to any one of claims 1 to 6, characterized in that: Determining the traveling direction of the train in the current cycle according to all remaining first pulse signals includes: For any remaining first pulse signal, determining a phase difference and a front-to-back sequence between a first channel signal and a second channel signal in the first pulse signal; Determine the train direction represented by the first pulse signal according to the phase difference and the front-to-back sequence; The traveling direction of the train in the current cycle is determined according to the train directions represented by all the remaining first pulse signals.

8. The speed measurement method according to claim 7, characterized in that: After determining the train direction represented by the first pulse signal according to the phase difference and the front-to-back sequence, the method further includes: Determining whether the directions of the trains are consistent; If so, the step of determining the travel direction of the train in the current cycle based on the train directions represented by all the remaining first pulse signals is entered.

9. A speed measuring device, characterized in that: include: Memory for storing computer programs; A processor, configured to implement the steps of the speed measurement method according to any one of claims 1 to 8 when executing the computer program.

10. A speed measurement system, characterized in that: It includes a host computer and an OPG, and also includes a speed measuring device as claimed in claim 9; The speed measuring device is connected to the host computer and the OPG respectively.

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