Train reference speed calculation method, electronic equipment and rail train

Abstract

The present invention is applicable to the field of rail vehicle technology and provides a method for calculating a train reference speed, an electronic device, and a rail train. The method comprises: obtaining the first wheelset speed of each wheelset under any control unit of the train in the current cycle; determining the second wheelset speed of each wheelset in the current cycle based on the second wheelset speeds of each wheelset in the previous two cycles and the first wheelset speeds of each wheelset in the current cycle; determining the first reference speed corresponding to the control unit in the current cycle based on the second wheelset speeds of each wheelset in the current cycle and the operating conditions of the train; and determining the second reference speed corresponding to the control unit in the current cycle based on the first reference speed corresponding to the control unit in the current cycle, the second reference speed corresponding to the control unit in the previous cycle, and the continuous crossing of the speeds of each wheelset under the control unit in the current cycle. The present invention can more accurately calculate the reference speed of the train.

Description

Technical Field

[0001] The present invention belongs to the technical field of rail vehicles, and in particular relates to a train reference speed calculation method, electronic equipment and a rail train. Background Art

[0002] Currently, existing anti-skid systems, both domestically and internationally, primarily rely on speed differential, deceleration, slip ratio, and deceleration differential to determine slippage. The speed differential and slip ratio are determined based on the train's reference speed. The control unit calculates the axle speed, axle deceleration, and vehicle speed, as measured by the vehicle's speed sensors. It then determines the train's slippage status based on the slip difference between each axle speed and the reference speed, as well as the change in each axle's deceleration. Therefore, when wheel-rail adhesion is poor and the wheelset begins to slip, the control unit immediately controls the anti-skid valve to adjust the braking force, thereby suppressing slippage and preventing wheelset abrasion. It also leverages adhesion to shorten braking distances under adverse adhesion conditions. Therefore, accurate reference speed calculation is crucial for effective anti-skid control and safe train operation. Summary of the Invention

[0003] In view of this, embodiments of the present invention provide a method for calculating a train reference speed, an electronic device, and a rail train, so as to more accurately calculate the reference speed of the train.

[0004] A first aspect of an embodiment of the present invention provides a method for calculating a train reference speed, comprising:

[0005] Get the first wheelset speed of each wheelset under any control unit of the train in this cycle;

[0006] Determine the second wheelset speed of each wheelset in the current cycle based on the second wheelset speed of each wheelset in the previous two cycles and the first wheelset speed of each wheelset in the current cycle;

[0007] Determine a first reference speed corresponding to the control unit in this cycle according to the second wheelset speed of each wheelset in this cycle and the operating condition of the train;

[0008] The second reference speed corresponding to the control unit in this cycle is determined based on the first reference speed corresponding to the control unit in this cycle, the second reference speed corresponding to the control unit in the previous cycle, and the continuous out-of-bounds speed of each wheel pair under the control unit in this cycle.

[0009] In conjunction with the first aspect, in a possible implementation of the first aspect, obtaining the first wheelset speed of each wheelset under any control unit of the train in the current cycle includes:

[0010] Obtain the number of sensor pulses per unit time collected by any control unit speed sensor in this cycle;

[0011] Determine the first wheelset speed of each wheelset in this cycle based on the number of sensor pulses, the wheel diameter of each wheelset, and the wheel diameter correction coefficient corresponding to each wheelset calculated in real time;

[0012] Determine whether the speed of the first wheelset of each wheelset in this cycle exceeds the limit;

[0013] If the first wheelset speed of a wheelset in this cycle exceeds the limit, the first wheelset speed of the wheelset in this cycle is recalculated based on the first wheelset speed of the wheelset in the previous cycle.

[0014] Furthermore, the method for calculating the wheel diameter correction coefficient corresponding to each wheel pair in real time includes:

[0015] Any wheelset of the trailer after wheel turning is used as the reference wheelset;

[0016] Set the initial wheel diameter correction coefficient of each wheelset and calculate the difference between the first wheelset speed of each wheelset under the control unit and the first wheelset speed of the reference wheelset.

[0017] In each cycle, if the difference corresponding to any wheelset exceeds the preset difference threshold and the number of continuous cycles reaches the preset cycle threshold, the wheel diameter correction coefficient of the wheelset is adjusted once;

[0018] Adjustments include:

[0019] If the first wheelset speed of the wheelset is greater than the first wheelset speed of the reference wheelset, the wheel diameter correction coefficient of the wheelset is reduced; if the first wheelset speed of the wheelset is less than the first wheelset speed of the reference wheelset, the wheel diameter correction coefficient of the wheelset is increased; wherein, if the adjusted wheel diameter correction coefficient is greater than the preset upper and lower limits of the wheel diameter correction coefficient, the upper limit value is used as the adjusted wheel diameter correction coefficient; if the adjusted wheel diameter correction coefficient is less than the preset lower limit value of the wheel diameter correction coefficient, the lower limit value is used as the adjusted wheel diameter correction coefficient.

[0020] In conjunction with the first aspect, in a possible implementation of the first aspect, determining the second wheelset speed of each wheelset in the current cycle based on the second wheelset speeds of each wheelset in the previous two cycles and the first wheelset speeds of each wheelset in the current cycle includes:

[0021]

[0022] V=P1+P2+P3;

[0023] P1=V0-2JV′0+V″0;

[0024] P2=(2J-1)V′;

[0025] P3 = K(V′-V″);

[0026]

[0027] Among them, V D is the speed of the second wheelset of a wheelset in this cycle, V′ D is the second wheelset speed of the wheelset in the previous cycle, V is the median value of the second wheelset speed of the wheelset in this cycle, V0 is the first wheelset speed of the wheelset in this cycle, V′0 is the first wheelset speed of the wheelset in the previous cycle, V″0 is the first wheelset speed of the wheelset in the previous cycle, V′ is the median value of the second wheelset speed of the wheelset in the previous cycle, V″ is the median value of the second wheelset speed of the wheelset in the previous cycle, K is the speed adjustment coefficient and decreases with increasing speed, C1 is the unit conversion coefficient, C2 is the angle correction value, J is the cosine value of the wheelset rotation angle and decreases with increasing speed, Z is the tooth value of the wheelset, and Numb / N is the number of sensor pulses per unit time in this cycle.

[0028] In conjunction with the first aspect, in a possible implementation of the first aspect, determining the first reference speed corresponding to the control unit in the current cycle based on the second wheelset speed of each wheelset in the current cycle and the operating condition of the train includes:

[0029] Select the maximum second wheelset speed and the minimum second wheelset speed of the control unit in this cycle from the maximum second wheelset speed that did not cross the limit under the control unit in the previous cycle, the minimum second wheelset speed that did not cross the limit under the control unit in the previous cycle, and the second wheelset speeds of each wheelset under the control unit in this cycle;

[0030] Calculate the weight coefficient W according to the operating conditions of the train;

[0031] Based on the maximum value of the second wheel pair speed, the minimum value of the second wheel pair speed and the weight coefficient W of the control unit in this period, the first reference speed corresponding to the control unit in this period is determined.

[0032] Furthermore, the weight coefficient is calculated according to the operating conditions of the train, including:

[0033] In the non-braking state and when the maximum speed of the second wheel pair and the minimum speed of the second wheel pair meet the preset conditions, the weight coefficient W increases in each cycle until it reaches the preset maximum weight limit;

[0034] Otherwise, the weight coefficient W decreases in each cycle until it reaches a preset minimum weight limit.

[0035] In conjunction with the first aspect, in a possible implementation of the first aspect, determining the second reference speed corresponding to the control unit in the current cycle according to the first reference speed corresponding to the control unit in the current cycle, the second reference speed corresponding to the control unit in the previous cycle, and the continuous out-of-bounds speed of each wheelset under the control unit in the current cycle includes:

[0036] If any wheelset in the control unit is marked as continuously exceeding the speed limit during this cycle, then according to V W =V′ W +K3 determines the second reference speed corresponding to the control unit in this cycle, V′ W is the second reference speed corresponding to the control unit in the previous cycle, and K3 is the preset change;

[0037] If no wheelset in the control unit is marked as continuously exceeding the speed limit in this cycle and V′ W If the speed is less than the preset reference speed threshold, then according to V W =min(V′ W +a3, R0) determines the second reference speed corresponding to the control unit in this cycle, a3 is a preset value, and R0 is the first reference speed of this cycle;

[0038] If no wheelset in the control unit is marked as continuously exceeding the speed limit in this cycle and V′ W is not less than the preset threshold, then directly according to V W =R0 determines the second reference speed corresponding to the control unit in this cycle.

[0039] In conjunction with the first aspect, in a possible implementation of the first aspect, a method for marking a wheelset whose speed continuously exceeds a speed limit includes:

[0040] For each wheelset, define two positive integer parameters cal_1 and cal_2 with initial values ​​of 0;

[0041] When cal_1 does not reach the preset parameter upper limit, the speed of the first wheelset in the wheelset increases by 1 each time it crosses the limit, and the wheelset is marked as continuously crossing the limit. When cal_1 reaches the preset parameter upper limit, the speed of the first wheelset in the wheelset increases by 10 each time it crosses the limit. When the speed of the first wheelset in the wheelset does not cross the limit, cal_1 and cal_2 are reduced by 1.

[0042] If the speed of the first wheelset in the current cycle does not exceed the limit and cal_2 of the current cycle is equal to 0, the speed continuous exceeding limit flag of the wheelset is cancelled; otherwise, the speed continuous exceeding limit flag of the wheelset is maintained.

[0043] A second aspect of an embodiment of the present invention provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps in the first aspect and any possible implementation of the first aspect are implemented.

[0044] A third aspect of an embodiment of the present invention provides a railway train, comprising the electronic device according to the second aspect.

[0045] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0046] The embodiment of the present invention combines the second wheelset speed of each wheelset in the previous two cycles and the first wheelset speed of each wheelset in the current cycle, and performs filtering to obtain the second wheelset speed of each wheelset in the current cycle, so that the calculation of the wheelset speed is more accurate; and, considering the operating conditions of the train and the continuous speed exceeding the limit, the final reference speed is determined to achieve the optimal anti-skid control effect and ensure the safe operation of the train. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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 paying any creative work.

[0048] Figure 1 1 is a schematic diagram of an implementation flow of a method for calculating a train reference speed provided by an embodiment of the present invention;

[0049] Figure 2 1 is a schematic diagram of a calculation flow of a wheel diameter correction coefficient provided by an embodiment of the present invention;

[0050] Figure 3 1 is a schematic diagram of a calculation flow of a wheelset speed according to an embodiment of the present invention;

[0051] Figure 4 1 is a schematic diagram of a reference speed calculation process provided by an embodiment of the present invention;

[0052] Figure 5 1 is a schematic diagram of a flow chart for determining if a speed exceeds a limit according to an embodiment of the present invention;

[0053] Figure 6 It is a structural diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0054] In the following description, specific details such as particular system structures and techniques are provided for purposes of illustration, not limitation, to facilitate a thorough understanding of the embodiments of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

[0055] In order to illustrate the technical solution of the present invention, specific embodiments are provided below.

[0056] The selection and calculation of reference speeds are crucial for anti-skid control and safe train operation. The accuracy of wheelset speed measurement is a key issue. This accuracy is easily affected by factors such as track surface conditions and the external environment, and requires indirect calculation and estimation through filtering and adjustment. For example, the following prior art solutions are available:

[0057] The ideal reference speed should be the vehicle speed, but it is difficult to obtain the vehicle speed during vehicle operation, so a simulated speed that is as close to the vehicle speed as possible is usually used as the reference speed. The reference speed is obtained according to the following steps: (1) Compare the speeds of the four axles in a vehicle and take the maximum value as the reference speed. (2) If the speeds of the four axles decrease rapidly, when the deceleration of the axle with the fastest deceleration exceeds ah (ah is the assumed maximum deceleration of the vehicle), the reference speed will be calculated based on the hypothetical speed with this deceleration ah using an equivalent straight line bridge until the speed of another axle exceeds this hypothetical speed. (3) If the adhesion condition is extremely poor, the speed of the four axles will decrease for a long time, causing the equivalent straight line to be too long, and the reference speed will deviate further and further from the vehicle speed. In this case, the brake cylinder pressure on the wheelset with the highest rotation speed must be specifically reduced to readjust the reference speed to be close to the vehicle speed.

[0058] The inventors of this application have discovered that this solution has the following shortcomings: during the braking process of the train, the speed of each axle is compared with the reference speed for anti-skid judgment and control, and the selection of reference speed should be different under different working conditions. The calculation of the above reference speed does not take into account the changes in wheel diameter during operation, different filtering parameters in different speed intervals, and the selection of reference speed when the speed exceeds the limit, which affects the calculation accuracy of the reference speed.

[0059] Therefore, this application provides a method for calculating the train reference speed, see Figure 1 As shown, the method includes the following steps:

[0060] Step S101: Obtain the first wheelset speed of each wheelset under any control unit of the train in this cycle.

[0061] In this embodiment, a train group is composed of multiple vehicles (or multiple carriages), each vehicle has two bogies, and each bogie has two axles (wheel pairs). The control mode of the train can be vehicle control, frame control or axle control. In the vehicle control mode, the whole vehicle has only one control unit, and all wheel pairs are controlled by the control unit. In the frame control mode, one control unit only controls the two wheel pairs of the corresponding bogie. In the axle control mode, one control unit only controls the corresponding wheel pair. Each control unit corresponds to a reference speed, and the control unit periodically calculates the reference speed and controls it, for example, each cycle is 10ms. Among them, the first wheel pair speed of the wheelset can be directly obtained by collecting the speed sensor or obtained after further correction by the following method of the present application.

[0062] Step S102: determining the second wheelset speed of each wheelset in the current cycle according to the second wheelset speed of each wheelset in the previous two cycles and the first wheelset speed of each wheelset in the current cycle.

[0063] In this embodiment, when the speed is high, the pulse signal frequency is high, resulting in a small error in the calculated speed. When the speed is low, the pulse signal frequency is low, resulting in a large error in the calculated speed, which is susceptible to signal interference and inaccurate calculations. To reduce the speed calculation error, filtering is performed by combining the second wheelset speed of each wheelset in the previous two cycles with the first wheelset speed of each wheelset in the current cycle to improve the accuracy of the wheelset speed calculation.

[0064] Step S103: Determine a first reference speed corresponding to the control unit in this cycle according to the second wheelset speed of each wheelset in this cycle and the operating condition of the train.

[0065] In this embodiment, during the operation of the train, the train control system needs to measure the reference speed of the train in real time. Under different working conditions, the reference speed of the train should be selected in different ways.

[0066] For example,

[0067] When the vehicle is in a non-braking state, the anti-skid protection function of the air brake system is not activated, and the speed of each axle of the train will not be lower than the actual speed of the train. At this time, the reference speed calculated by the system selects the lowest axle speed of each axle in the brake control unit.

[0068] When the vehicle is in braking state (including emergency braking), but the anti-skid protection has not been activated, the braking system is in normal working condition and the speed of each axle of the train will not be higher than the actual speed of the train. At this time, the reference speed calculated by the system selects the maximum axle speed of each axle in the brake control unit.

[0069] When the vehicle is in braking state, and the difference between the current axle speed and the reference speed is greater than 5% (or the axle deceleration of the current axle is greater than 4.5m / s 2 ), the anti-skid protection function is activated, and the brake control valve of the corresponding bogie will automatically enter the axle control mode from the bogie control mode, and prepare for the axle control anti-skid protection; at the same time, the brake control valve (defined as a ground speed measurement valve, usually two valves on the trailer, during a braking process, the ground speed measurement works alternately between the two towing axles between two different bogies) will start "ground speed measurement" 2 seconds after the above situation occurs (that is, a short-term exhaust action is performed on the specified part of the towing axles in order to obtain an axle speed relative to the free axle, that is, it provides a "seed player" for this brake control unit to calculate the reference speed. In this way, the reference speed in this brake control unit can be closer to the actual speed of the vehicle. The reference speed is the maximum axle speed in the brake control unit.

[0070] Step S104: Determine the second reference speed corresponding to the control unit in this cycle based on the first reference speed corresponding to the control unit in this cycle, the second reference speed corresponding to the control unit in the previous cycle, and the speed of each wheel pair under the control unit in this cycle that continues to exceed the limit.

[0071] In this embodiment, in order to ensure the accuracy of the reference speed and eliminate the influence of speed exceeding the limit caused by system interference, it is also necessary to determine the situation of continuous speed exceeding the limit when calculating the final reference speed. Among them, speed exceeding the limit can be defined as the first round of speed change rate exceeding 12.5m / s 2 This embodiment improves the accuracy of reference speed calculation by designing a calculation strategy for the reference speed when the speed continuously exceeds the limit.

[0072] The embodiment of the present invention combines the second wheelset speed of each wheelset in the previous two cycles and the first wheelset speed of each wheelset in the current cycle, and performs filtering to obtain the second wheelset speed of each wheelset in the current cycle, so that the calculation of the wheelset speed is more accurate; and, considering the operating conditions of the train and the continuous speed exceeding the limit, the final reference speed is determined to achieve the optimal anti-skid control effect and ensure the safe operation of the train.

[0073] As a possible implementation, the first wheelset speed of each wheelset under any control unit of the train in this cycle is obtained in step S101, which can be described in detail as follows:

[0074] Obtain the number of sensor pulses per unit time collected by any control unit speed sensor in this cycle;

[0075] Determine the first wheelset speed of each wheelset in this cycle based on the number of sensor pulses, the wheel diameter of each wheelset, and the wheel diameter correction coefficient corresponding to each wheelset calculated in real time;

[0076] Determine whether the speed of the first wheelset of each wheelset in this cycle exceeds the limit;

[0077] If the first wheelset speed of a wheelset in this cycle exceeds the limit, the first wheelset speed of the wheelset in this cycle is recalculated based on the first wheelset speed of the wheelset in the previous cycle.

[0078] In this embodiment, due to different wheel wear in actual train operation, there may be a small difference in wheel diameter between different wheelsets, which may affect the accuracy of wheel speed calculation. By controlling variables, in the case of no braking and no coasting, the influence of factors other than wheel diameter difference on wheel speed can be controlled, and the speeds of each wheelset can be compared to calculate the wheel diameter correction coefficient K. 修正 , improving the accuracy of anti-skid control.

[0079] At the same time, considering the speed out of bounds, the first round of speed calculation formula can be as follows:

[0080]

[0081] Among them, K 修正 It represents the wheel diameter correction coefficient, Numb / N is the number of sensor pulses received by the control unit per unit time, Z is the tooth value, D is the wheel diameter value, K_Mout is the speed change out of bounds, 1 indicates out of bounds, and ±0.125m / s represents the upper and lower limits of speed out of bounds every 10ms.

[0082] Furthermore, the method for calculating the wheel diameter correction coefficient corresponding to each wheelset in real time includes:

[0083] Any wheelset of the trailer after wheel turning is used as the reference wheelset;

[0084] Set the initial wheel diameter correction coefficient of each wheelset and calculate the difference between the first wheelset speed of each wheelset under the control unit and the first wheelset speed of the reference wheelset.

[0085] In each cycle, if the difference corresponding to any wheelset exceeds the preset difference threshold and the number of continuous cycles reaches the preset cycle threshold, the wheel diameter correction coefficient of the wheelset is adjusted once;

[0086] The adjustments include:

[0087] If the first wheelset speed of the wheelset is greater than the first wheelset speed of the reference wheelset, the wheel diameter correction coefficient of the wheelset is reduced; if the first wheelset speed of the wheelset is less than the first wheelset speed of the reference wheelset, the wheel diameter correction coefficient of the wheelset is increased; wherein, if the adjusted wheel diameter correction coefficient is greater than the preset upper and lower limits of the wheel diameter correction coefficient, the upper limit value is used as the adjusted wheel diameter correction coefficient; if the adjusted wheel diameter correction coefficient is less than the preset lower limit value of the wheel diameter correction coefficient, the lower limit value is used as the adjusted wheel diameter correction coefficient.

[0088] In this embodiment, considering that the trailer has no power, the axle speed is closer to the actual speed. The second axle of the first bogie of the trailer after wheel turning can be used as the average speed reference axis (this axle is close to the middle of the vehicle, with other axles in front and behind, and the speed of this axle is relatively stable). The wheel diameter correction coefficients of other axles are calculated. When the axle speed is greater than the average speed, the correction coefficient decreases; when it is less than the average speed, the correction coefficient increases. For example, see Figure 2 As shown, K 修正[i] Indicates the wheel diameter correction coefficient of the i-th axis, K 修正[i]Assume that the initial value is 1000, and the second axle of the first bogie of the trailer after wheel turning is used as the reference axle. When the difference percentage between the first wheelset speed of the wheelset and the first wheelset speed of the reference axle exceeds 0.06% and lasts for 25 cycles, if the wheelset speed is greater than the reference axle speed, the correction factor is reduced by 1, and if the wheelset speed is less than the reference axle speed, the correction factor is increased by 1. In order to prevent over-adjustment, the correction factor is limited to 1000-M <K 修正[i] <1000+M, where M is the maximum wheel diameter wear coefficient adjustment, with a typical value of 83.

[0089] As a possible implementation, in step S102, the second wheelset speed of each wheelset in the current cycle is determined based on the second wheelset speed of each wheelset in the previous two cycles and the first wheelset speed of each wheelset in the current cycle, which can be described in detail as follows:

[0090]

[0091] V=P1+P2+P3;

[0092] P1=V0-2JV′0+V″0;

[0093] P2=(2J-1)V′;

[0094] P3 = K(V′-V″);

[0095]

[0096] Among them, V D is the speed of the second wheelset of a wheelset in this cycle, V′ D is the second wheelset speed of the wheelset in the previous cycle, V is the median value of the second wheelset speed of the wheelset in this cycle, V0 is the first wheelset speed of the wheelset in this cycle, V′0 is the first wheelset speed of the wheelset in the previous cycle, V″0 is the first wheelset speed of the wheelset in the previous cycle, V′ is the median value of the second wheelset speed of the wheelset in the previous cycle, V″ is the median value of the second wheelset speed of the wheelset in the previous cycle, K is the speed adjustment coefficient and decreases with increasing speed, C1 is the unit conversion coefficient, C2 is the angle correction value, J is the cosine value of the wheelset rotation angle and decreases with increasing speed, Z is the tooth value of the wheelset, and Numb / N is the number of sensor pulses per unit time in this cycle.

[0097] In this embodiment, when the speed is high, the pulse signal frequency is high, and the error in the calculated speed is small. When the speed is low, the pulse signal frequency is low, the error in the calculated speed is large, and the calculation is easily affected by signal interference, resulting in inaccurate calculations. To reduce the error in the calculated speed, a wheelset speed filtering calculation method is invented. When the speed is high, the signal collected by the speed sensor is mainly considered. When the speed is low, the calculation is mainly based on the changing trend of the wheelset speed itself. Among them, the P1 part considers the impact of the sensor calculation speed on the intermediate calculated wheelset speed, the P2 part considers the impact of the intermediate calculated wheelset speed at the previous moment, and the P3 part considers the impact of the change value of the intermediate calculated wheelset speed at the previous moment.

[0098] When the speed is small, J is close to 1, and the speed change value calculated by the sensor is small in a short time, that is, V0-V′0≈V′0-V″0, then the value of the P1 part is P1=V0-2JV′0+V″0≈(2-2J)V′0≈0, P1 is approximately 0, so the sensor-calculated speed has little effect on the intermediate calculated wheelset speed; the value of the P2 part is P2=(2J-1)V′≈V′, J is close to 1, P2 is approximately V′, so the intermediate calculated wheelset speed has a greater impact at the previous moment; the value of the P3 part is P3=K(V′-V″)≈V′-V″, K is close to 1, P3 is approximately V′-V″, so the change value of the intermediate calculated wheelset speed at the previous moment has a greater impact, and finally the intermediate calculated wheelset speed mainly depends on its own change trend, reducing the interference of inaccurate sensor signals at low speeds.

[0099] When the speed is large, J is close to 0.5, and the value of the P1 part is P1=V0-2JV′0+V″0≈(2-2J)V′0≈V′0, P1 is approximate to V′0, and the sensor calculation speed has a greater influence on the intermediate calculated wheelset speed; the value of the P2 part is P2=(2J-1)V′≈0, J is close to 0.5, P2 is approximate to 0, and the influence of the previous moment on the intermediate calculated wheelset speed is small; the value of the P3 part is P3=K(V′-V″)≈0.5(V′-V″), K is close to 0.5, and P3 is approximate to 0.5(V′-V″), which reduces the influence of the change value of the intermediate calculated wheelset speed at the previous moment, and finally the intermediate calculated wheelset speed mainly depends on the sensor calculation speed. Therefore, the proposed intermediate calculated wheelset speed calculation method effectively reduces the error caused by sensor interference while ensuring the accuracy of the speed.

[0100] Finally, by the difference adjustment function The intermediate calculated wheelset speed (that is, the intermediate value of the second wheelset speed) is filtered to obtain the final second wheelset speed.

[0101] For example, the specific calculation process of the second round of speed can be found in Figure 3As shown. Among them, the tooth value Z = 80, the wheel diameter value D = 0.815m, ±0.125m / s is the upper and lower limits of the speed every 10ms, and the unit of Numb / N is / s. C1 = 0.02, C2 = 5, and the value of J decreases as the speed increases. The value of parameter K is:

[0102]

[0103] As a possible implementation, the first reference speed corresponding to the control unit in this cycle is determined according to the second wheelset speed of each wheelset in this cycle and the operating condition of the train, which can be detailed as follows:

[0104] Select the maximum second wheelset speed and the minimum second wheelset speed of the control unit in this cycle from the maximum second wheelset speed that did not cross the limit under the control unit in the previous cycle, the minimum second wheelset speed that did not cross the limit under the control unit in the previous cycle, and the second wheelset speeds of each wheelset under the control unit in this cycle;

[0105] Calculate the weight coefficient W according to the operating conditions of the train;

[0106] Based on the maximum value of the second wheel pair speed, the minimum value of the second wheel pair speed and the weight coefficient W of the control unit in this period, the first reference speed corresponding to the control unit in this period is determined.

[0107] Furthermore, the weight coefficient is calculated according to the operating conditions of the train, including:

[0108] In the non-braking state and when the maximum speed of the second wheel pair and the minimum speed of the second wheel pair meet the preset conditions, the weight coefficient W increases in each cycle until it reaches the preset maximum weight limit;

[0109] Otherwise, the weight coefficient W decreases in each cycle until it reaches a preset minimum weight limit.

[0110] In this embodiment, the reference speed calculation is affected by the operating conditions. The maximum and minimum second wheelset speeds for all wheelsets are calculated within the brake control unit. The first reference speed is calculated based on the maximum and minimum second wheelset speeds and the operating condition (non-braking condition, braking condition, or a transition between the two conditions).

[0111] For example, taking the frame control as an example (the axle control and vehicle control are similar and will not be described in detail), the maximum speed V of the second wheel max and minimum value V min The calculation formula is as follows:

[0112]

[0113] V min =min(Vmax ,V D1 ,V D2 ,min(V CANj ))

[0114] Among them, max(V CANj ) refers to the maximum wheel speed that has not been exceeded and transmitted by the brake control unit network in the previous cycle, f cal (X) represents the difference adjustment function, f cal (X) = X' + (XX') cal, X' is the value of X in the previous cycle, V D1 、V D2 Indicates the wheelset speed of the two wheelsets of this bogie.

[0115] According to the second round of maximum speed V max , the minimum speed of the second round V min The formula for calculating the first reference speed R0 according to the operating conditions is as follows:

[0116]

[0117] Wherein, W is the weight parameter, which can be calculated as follows: in the non-braking state, V min >0.5m / s and V max / Vmin When W is greater than 1.05, W increases by 1 in each cycle until it reaches 150; in other cases, W decreases by 1 in each cycle until it reaches 0. The change in the W weight parameter represents the reaction time of the system, meeting the requirements of the transition process between non-braking and braking conditions. Under non-braking conditions, the wheelset speed is not less than the train speed, and the W weight coefficient increases from 0 to 150, and the value of R0 tends to V min When the braking condition is executed, the value of W starts to decrease from 150. Within 0.75s, W is greater than 75, and R0 still takes the value V min , so that the system has a certain response time, W decreases from 75 to 0 in the process of R0 taking the weighted average coefficient, R0 from V min to V max Transition to avoid system oscillation caused by direct change from minimum value to maximum value.

[0118] The calculation process of the first reference speed in the above example can be found in Figure 4 shown.

[0119] As a possible implementation, in step S104, the second reference speed corresponding to the control unit in the current cycle is determined based on the first reference speed corresponding to the control unit in the current cycle, the second reference speed corresponding to the control unit in the previous cycle, and the continuous out-of-bounds speed of each wheelset under the control unit in the current cycle. This can be described in detail as follows:

[0120] If any wheelset in the control unit is marked as continuously exceeding the speed limit during this cycle, then according to V W =V′ W +K3 determines the second reference speed corresponding to the control unit in this cycle, V′ W is the second reference speed corresponding to the control unit in the previous cycle, and K3 is the preset change;

[0121] If no wheelset in the control unit is marked as continuously exceeding the speed limit in this cycle and V′ W If the speed is less than the preset reference speed threshold, then according to V W =min(V′ W +a3, R0) determines the second reference speed corresponding to the control unit in this cycle, a3 is a preset value, and R0 is the first reference speed of this cycle;

[0122] If no wheelset in the control unit is marked as continuously exceeding the speed limit in this cycle and V′ W is not less than the preset threshold, then directly according to V W =R0 determines the second reference speed corresponding to the control unit in this cycle.

[0123] In this embodiment, illustratively, the second reference speed calculation formula is as follows:

[0124]

[0125] When K_Vout=1, the speed is out of bounds, the calculated speed has low reliability, and the second reference speed is based on the second reference speed of the previous period, and the preset change K3 is increased. Since the calculated speed reliability is low at this time, the value of K3 is further set by the ground speed measurement function. When the anti-skid braking system detects that the shaft speed difference is greater than 5% or the shaft deceleration is greater than 4.5m / s 2 The train is then judged to be coasting, and ground speed measurement is started at the same time. Short-term exhaust action is performed on some designated trailing axles to obtain an axle speed relative to the free axle. When the ground speed value exceeds 150% of the average train speed and the vehicle is moving but the speed acquisition is stationary or too low, the value range of K3 is -0.001 to -0.00325 m / s, and the final reference speed is slowly decreased until the system returns to stability; when the ground speed value is within the normal range, the value range of K3 is -0.01 to -0.0125 m / s, and the second reference speed, i.e. the final reference speed, is calculated according to the deceleration of normal braking-rapid braking.

[0126] When K_Vout=0, if the reference speed of the previous cycle is less than 0.8m / s, the train does not perform anti-skid braking control and enters the parking or traction acceleration state. The final reference speed takes the smaller value of the first reference speed and the second reference speed adjustment value of the previous cycle, limiting V WThe speed increase ensures the accuracy of the reference speed in the traction state.

[0127] When K_Vout=0 and the reference speed of the previous cycle is greater than 0.8 m / s, the final reference speed directly takes the first reference speed.

[0128] As a possible implementation, see Figure 5 As shown, the method for marking a wheelset whose speed continuously exceeds the limit includes:

[0129] For each wheelset, define two positive integer parameters cal_1 and cal_2 with initial values ​​of 0;

[0130] When cal_1 does not reach the preset parameter upper limit, the speed of the first wheelset in the wheelset increases by 1 each time it crosses the limit, and the wheelset is marked as continuously crossing the limit. When cal_1 reaches the preset parameter upper limit, the speed of the first wheelset in the wheelset increases by 10 each time it crosses the limit. When the speed of the first wheelset in the wheelset does not cross the limit, cal_1 and cal_2 are reduced by 1.

[0131] If the speed of the first wheelset in the current cycle does not exceed the limit and cal_2 of the current cycle is equal to 0, the speed continuous exceeding limit flag of the wheelset is cancelled; otherwise, the speed continuous exceeding limit flag of the wheelset is maintained.

[0132] In this embodiment, in order to ensure the accuracy of the reference speed and eliminate the influence of speed crossing the limit caused by system interference, it is also necessary to judge whether the speed continues to cross the limit when calculating the final reference speed. K_Mout records the situation where the wheel speed (referring to the first wheel speed) crosses the limit in this cycle. The change rate of the wheel speed exceeds 12.5m / s. 2When the speed exceeds a certain limit, K_Mout is set to 1; otherwise, it is set to 0. K_Vout is used as an out-of-bounds flag to record the occurrence of persistent speed violations, serving as a basis for determining the severity of the speed violations and the reliability of the calculated speed. When the number of speed out-of-bounds cycles does not exceed a certain limit, the system interference is not severe, and K_Mout and K_Vout are both set to 0. When the number of speed out-of-bounds cycles exceeds a certain limit, the system interference is severe, and K_Mout remains at 0 for a period of time before K_Vout is set to 0. Define two counters, cal_1 = 0 and cal_2 = 0: cal_1∈[0,t1] records the cumulative number of out-of-bounds cycles, and cal_2∈[0,t2] records the number of cycles required for the out-of-bounds flag to be set to 0. When the cumulative number of speed out-of-bounds cycles, cal_1, does not reach t1, K_Mout and K_Vout are both set to 0. When the speed continues to exceed t1, causing cal_1 to reach t1, cal_2 increments by 10 per cycle, and K_Mout remains at 0 for cal_2 cycles before K_Vout is set to 0. In any cycle, if the speed of the first wheel pair does not exceed the limit and cal_2 is equal to 0, the wheel pair speed continuous out-of-bounds flag is canceled.

[0133] In view of the above, the main inventive aspects of this embodiment include:

[0134] 1) By studying the impact of wheel diameter changes on the reference speed, the correction coefficient is calculated to automatically adjust for small wheel diameter differences that occur during normal train operation;

[0135] 2) Select different filter coefficients in different speed ranges to ensure the stability of the obtained speed value;

[0136] 3) The final reference speed is determined by taking into account the operating mode switching and the continuous speed exceeding the limit to achieve the optimal anti-skid control effect and ensure the safe operation of the train.

[0137] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0138] Figure 6 FIG is a schematic diagram of an electronic device 60 provided by an embodiment of the present invention. Figure 6 As shown, the electronic device 60 of this embodiment includes: a processor 61, a memory 62, and a computer program 63 stored in the memory 62 and executable on the processor 61, such as a train reference speed calculation program. When the processor 61 executes the computer program 63, the steps in the above-mentioned embodiments of the train reference speed calculation method are implemented, such as Figure 1 Steps S101 to S104 are shown.

[0139] Exemplarily, the computer program 63 may be divided into one or more modules / units, one or more of which are stored in the memory 62 and executed by the processor 61 to implement the present invention. One or more modules / units may be a series of computer program instruction segments capable of performing specific functions, and the instruction segments are used to describe the execution process of the computer program 63 in the electronic device 60. For example, the computer program 63 may be divided into an acquisition module, a first calculation module, a second calculation module, and a third calculation module (modules in the virtual device), and the specific functions of each module are as follows:

[0140] The acquisition module is used to obtain the first wheelset speed of each wheelset under any control unit of the train in this cycle.

[0141] The first calculation module is used to determine the second wheelset speed of each wheelset in the current cycle according to the second wheelset speed of each wheelset in the previous two cycles and the first wheelset speed of each wheelset in the current cycle.

[0142] The second calculation module is used to determine the first reference speed corresponding to the control unit in this cycle according to the second wheelset speed of each wheelset in this cycle and the operating condition of the train.

[0143] The third calculation module is used to determine the second reference speed corresponding to the control unit in this cycle based on the first reference speed corresponding to the control unit in this cycle, the second reference speed corresponding to the control unit in the previous cycle, and the continuous out-of-bounds speed of each wheel pair under the control unit in this cycle.

[0144] The electronic device 60 may be a computing device such as a desktop computer, a notebook computer, a PDA, or a cloud server. The electronic device 60 may include, but is not limited to, a processor 61 and a memory 62. It will be understood by those skilled in the art that Figure 6 It is only an example of the electronic device 60 and does not constitute a limitation of the electronic device 60. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the electronic device 60 may also include input and output devices, network access devices, buses, etc.

[0145] The processor 61 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0146] The memory 62 can be an internal storage unit of the electronic device 60, such as a hard drive or memory of the electronic device 60. The memory 62 can also be an external storage device of the electronic device 60, such as a plug-in hard drive, a Smart Media Card (SMC), a Secure Digital (SD) card, a flash memory card, etc. equipped on the electronic device 60. Furthermore, the memory 62 can include both an internal storage unit of the electronic device 60 and an external storage device. The memory 62 is used to store computer programs and other programs and data required by the electronic device 60. The memory 62 can also be used to temporarily store data that has been output or is about to be output.

[0147] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0148] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0149] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present invention.

[0150] In the embodiments provided by the present invention, it should be understood that the disclosed devices / electronic devices and methods can be implemented in other ways. For example, the device / electronic device embodiments described above are merely schematic. For example, the division of modules or units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0151] Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0152] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0153] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the process in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form, etc. Computer-readable media may include: any entity or device that can carry computer program code, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electrical carrier signal, telecommunication signal and software distribution medium, etc.

[0154] An embodiment of the present invention further provides a rail vehicle, comprising the electronic device as described above.

[0155] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the scope of protection of the present invention.

Claims

1. A method for calculating a train reference speed, characterized in that: include: Get the first wheelset speed of each wheelset under any control unit of the train in this cycle; Determine the second wheelset speed of each wheelset in the current cycle based on the second wheelset speed of each wheelset in the previous two cycles and the first wheelset speed of each wheelset in the current cycle; Determine a first reference speed corresponding to the control unit in this cycle according to the second wheelset speed of each wheelset in this cycle and the operating condition of the train; Determine the second reference speed corresponding to the control unit in the current cycle according to the first reference speed corresponding to the control unit in the current cycle, the second reference speed corresponding to the control unit in the previous cycle, and the continuous crossing of the first wheelset speeds of each wheelset under the control unit in the current cycle; The crossing of the limit means that the rate of change of the wheelset speed exceeds 12.5m / s 2 .

2. The train reference speed calculation method according to claim 1, wherein: Get the first wheelset speed of each wheelset under any control unit of the train in this cycle, including: Obtain the number of sensor pulses per unit time collected by any control unit speed sensor in this cycle; Determine the first wheelset speed of each wheelset in this cycle based on the number of sensor pulses, the wheel diameter of each wheelset, and the wheel diameter correction coefficient corresponding to each wheelset calculated in real time; Determine whether the speed of the first wheelset of each wheelset in this cycle exceeds the limit; If the first wheelset speed of a wheelset in this cycle exceeds the limit, the first wheelset speed of the wheelset in this cycle is recalculated based on the first wheelset speed of the wheelset in the previous cycle.

3. The train reference speed calculation method according to claim 2, characterized in that: The method for calculating the wheel diameter correction coefficient corresponding to each wheelset in real time includes: Any wheelset of the trailer after wheel turning is used as the reference wheelset; Set the initial wheel diameter correction coefficient of each wheelset and calculate the difference between the first wheelset speed of each wheelset under the control unit and the first wheelset speed of the reference wheelset. In each cycle, if the difference corresponding to any wheelset exceeds the preset difference threshold and the number of continuous cycles reaches the preset cycle threshold, the wheel diameter correction coefficient of the wheelset is adjusted once; The adjustments include: If the first wheelset speed of the wheelset is greater than the first wheelset speed of the reference wheelset, the wheel diameter correction coefficient of the wheelset is reduced; if the first wheelset speed of the wheelset is less than the first wheelset speed of the reference wheelset, the wheel diameter correction coefficient of the wheelset is increased; wherein, if the adjusted wheel diameter correction coefficient is greater than the preset upper and lower limits of the wheel diameter correction coefficient, the upper limit value is used as the adjusted wheel diameter correction coefficient; if the adjusted wheel diameter correction coefficient is less than the preset lower limit value of the wheel diameter correction coefficient, the lower limit value is used as the adjusted wheel diameter correction coefficient.

4. The train reference speed calculation method according to claim 1, wherein: According to the second wheelset speeds of each wheelset in the previous two cycles and the first wheelset speeds of each wheelset in the current cycle, the second wheelset speeds of each wheelset in the current cycle are determined, including: ； ； ； ； ； ； in, is the speed of the second wheelset of a wheelset in this cycle, is the speed of the second wheelset of the wheelset in the previous cycle, is the median value of the second wheelset speed of this wheelset in this cycle, is the first wheelset speed of this wheelset in this cycle, is the first wheelset speed of the wheelset in the previous cycle, is the first wheelset speed of the wheelset in the previous cycle, is the median speed of the second wheelset of the wheelset in the previous cycle, is the median speed of the second wheelset of the wheelset in the previous cycle, is the speed adjustment coefficient and decreases as the speed increases. C 1 is the unit conversion factor, C 2 is the angle correction value, J is the cosine value of the wheelset's rotation angle and decreases with increasing speed. Z is the teeth value of the wheelset. Numb / N It is the number of sensor pulses per unit time in this cycle.

5. The train reference speed calculation method according to claim 1, wherein: Determining a first reference speed corresponding to the control unit in the current cycle according to the second wheelset speed of each wheelset in the current cycle and the operating condition of the train includes: Select the maximum second wheelset speed and the minimum second wheelset speed of the control unit in this cycle from the maximum second wheelset speed that did not cross the limit under the control unit in the previous cycle, the minimum second wheelset speed that did not cross the limit under the control unit in the previous cycle, and the second wheelset speeds of each wheelset under the control unit in this cycle; Calculate the weight coefficient according to the train's operating conditions W ; Based on the maximum value of the second wheel pair speed, the minimum value of the second wheel pair speed and the weight coefficient of the control unit in this cycle W Determine a first reference speed corresponding to the control unit in this cycle.

6. The train reference speed calculation method according to claim 5, characterized in that: The weight coefficient is calculated based on the train's operating conditions, including: In the non-braking state and when the maximum speed of the second wheel pair and the minimum speed of the second wheel pair meet the preset conditions, the weight coefficient W Increase in each cycle until the preset maximum weight limit is reached; Otherwise, the weight coefficient W It decreases in each cycle until it reaches the preset minimum weight limit.

7. The train reference speed calculation method according to claim 1, wherein: Determining the second reference speed corresponding to the control unit in the current cycle according to the first reference speed corresponding to the control unit in the current cycle, the second reference speed corresponding to the control unit in the previous cycle, and the continuous crossing of the first wheelset speeds of each wheelset under the control unit in the current cycle includes: If any wheelset in the control unit is marked as continuously out of speed during this cycle, Determine the second reference speed corresponding to the control unit in this cycle, is the second reference speed corresponding to the control unit in the previous cycle, is the preset change amount; If no wheelset in the control unit is marked as continuously out of speed during this cycle and If the speed is less than the preset reference speed threshold, Determine the second reference speed corresponding to the control unit in this cycle, is the default value, is the first reference speed of this cycle; If no wheelset in the control unit is marked as continuously out of speed during this cycle and If it is not less than the preset threshold, then Determine a second reference speed corresponding to the control unit in this cycle.

8. The train reference speed calculation method according to claim 1, wherein: Methods for marking wheelsets that consistently exceed speed limits include: For each wheelset, define two positive integer parameters cal_1 and cal_2 with initial values ​​of 0; When cal_1 does not reach the preset parameter upper limit, the speed of the first wheelset in the wheelset increases by 1 each time it crosses the limit, and the wheelset is marked as continuously crossing the limit. When cal_1 reaches the preset parameter upper limit, the speed of the first wheelset in the wheelset increases by 10 each time it crosses the limit. When the speed of the first wheelset in the wheelset does not cross the limit, cal_1 and cal_2 are reduced by 1. If the speed of the first wheelset in the current cycle does not exceed the limit and cal_2 of the current cycle is equal to 0, the speed continuous exceeding limit flag of the wheelset is cancelled; otherwise, the speed continuous exceeding limit flag of the wheelset is maintained.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 8 are implemented.

10. A railway train comprising the electronic device according to claim 9.

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