Rotating speed signal processing method and device of traction motor

Abstract

The invention provides a rotating speed signal processing method and device of a traction motor. The method comprises the steps of obtaining a square wave signal corresponding to the traction motor and the number of teeth of a gear disc; performing signal filtering on the square wave signal according to a time interval of adjacent jump edges in the square wave signal to obtain a filtered square wave signal; acquiring a current pulse period of the filtered square wave signal; and determining a rotating speed signal of the traction motor according to the number of teeth of the gear disc and the current pulse period. The influence of electromagnetic interference on the precision of the rotating speed signal can be effectively suppressed, and the precision of the rotating speed signal is improved.

Description

Technical Field

[0001] This application relates to the field of locomotive and rolling stock traction control technology, and in particular to a method and apparatus for processing the speed signal of a traction motor. Background Technology

[0002] In locomotive and rolling stock traction systems, the traction motor's speed signal is typically acquired by a speed-measuring gear and sensors (such as photoelectric encoders or magnetoelectric sensors) mounted on the motor shaft. The square wave signal output by the sensors is processed and used for motor speed calculation and closed-loop control. However, in actual operation, the speed signal may be subject to the following interferences:

[0003] 1. Electromagnetic interference (EMI): High-frequency switching of the traction converter and arc discharge of the pantograph-catenary system can cause glitches or abnormal jumps in the square wave signal, affecting the accuracy of speed calculation.

[0004] 2. Gear disk machining error: Uneven gear disk tooth pitch or eccentric installation will cause periodic fluctuations in the square wave signal, especially at high speeds.

[0005] Existing technologies typically employ hardware filtering (such as RC filtering) or software filtering (such as moving average) to suppress interference; however, it is difficult to maintain the accuracy of the speed signal measured under complex electromagnetic interference environments.

[0006] This section is intended to provide background or context for the embodiments of the invention set forth in the claims. The description herein is not an admission that it is prior art simply because it is included in this section. Summary of the Invention

[0007] To address at least one problem in the prior art, this application proposes a method and apparatus for processing the speed signal of a traction motor, which can effectively suppress the influence of electromagnetic interference on the accuracy of the speed signal and improve the accuracy of the speed signal.

[0008] To address the aforementioned technical problems, this application provides the following technical solution:

[0009] In a first aspect, this application provides a method for processing the speed signal of a traction motor, comprising:

[0010] Obtain the square wave signal and gear tooth count corresponding to the traction motor;

[0011] Based on the time interval between adjacent transition edges in the square wave signal, the square wave signal is filtered to obtain a filtered square wave signal.

[0012] Obtain the current pulse period of the filtered square wave signal; determine the rotational speed signal of the traction motor based on the number of teeth on the gear disk and the current pulse period.

[0013] In one embodiment, determining the rotational speed signal of the traction motor based on the number of teeth on the gear disc and the current pulse period includes:

[0014] The single-pulse rotational speed is determined based on the number of teeth on the gear disk and the current pulse period;

[0015] The rotational speed mode of the previous pulse cycle is obtained. If the rotational speed mode of the previous pulse cycle is a low-speed mode, it is determined whether the single-pulse rotational speed is less than a preset first rotational speed. If so, the rotational speed mode of the current pulse cycle is determined to be a low-speed mode, and the single-pulse rotational speed is determined as the rotational speed signal of the traction motor in the current pulse cycle.

[0016] In one embodiment, determining the rotational speed signal of the traction motor based on the number of teeth on the gear disc and the current pulse period further includes:

[0017] If the single pulse speed is greater than or equal to a preset first speed, then the speed mode of the current pulse cycle is determined to be high-speed mode;

[0018] Multiple consecutive pulse cycles are acquired, and the rotational speed signal of the traction motor in the current pulse cycle is determined based on the number of teeth of the gear disk and each pulse cycle, wherein the number of pulse cycles is the same as the number of teeth of the gear disk.

[0019] In one embodiment, after determining that the rotation speed mode of the current pulse cycle is a high-speed mode, the method further includes:

[0020] A time-smoothing switching method is used to switch the speed signal of the previous pulse cycle to the speed signal of the current pulse cycle.

[0021] In one embodiment, determining the rotational speed signal of the traction motor based on the number of teeth on the gear disc and the current pulse period includes:

[0022] The single-pulse rotational speed is determined based on the number of teeth on the gear disk and the current pulse period;

[0023] Obtain the rotation speed mode of the previous pulse cycle of the current pulse cycle. If the rotation speed mode of the previous pulse cycle is a high-speed mode, determine whether the single pulse rotation speed is greater than a preset second rotation speed. If so, determine that the rotation speed mode of the current pulse cycle is a high-speed mode.

[0024] Multiple consecutive pulse cycles are acquired, and the rotational speed signal of the traction motor in the current pulse cycle is determined based on the number of teeth of the gear disk and each pulse cycle, wherein the number of pulse cycles is the same as the number of teeth of the gear disk.

[0025] In one embodiment, determining the rotational speed signal of the traction motor based on the number of teeth on the gear disc and the current pulse period further includes:

[0026] If the single-pulse speed is less than or equal to the preset second speed, then the speed mode of the current pulse cycle is determined to be low speed mode, and the single-pulse speed is determined as the speed signal of the traction motor in the current pulse cycle.

[0027] In one embodiment, after determining that the rotational speed mode of the current pulse period is a low-speed mode, the method further includes:

[0028] A time-smoothing switching method is used to switch the speed signal of the previous pulse cycle to the speed signal of the current pulse cycle.

[0029] Secondly, this application provides a speed signal processing device for a traction motor, comprising:

[0030] The first acquisition module is used to acquire the square wave signal and the number of teeth on the gear disk corresponding to the traction motor.

[0031] The filtering module is used to filter the square wave signal according to the time interval between adjacent transition edges in the square wave signal to obtain the filtered square wave signal.

[0032] The second acquisition module is used to acquire the current pulse period of the filtered square wave signal;

[0033] The processing module is used to determine the rotational speed signal of the traction motor based on the number of teeth on the gear disk and the current pulse cycle.

[0034] Thirdly, this application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the speed signal processing method for the traction motor.

[0035] Fourthly, this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the traction motor speed signal processing method.

[0036] Fifthly, this application provides a computer program product, which includes a computer program that, when executed by a processor, implements the traction motor speed signal processing method.

[0037] As can be seen from the above technical solution, this application provides a method and apparatus for processing the speed signal of a traction motor. The method includes: acquiring a square wave signal corresponding to the traction motor and the number of teeth on the gear disk; filtering the square wave signal according to the time interval between adjacent transition edges in the square wave signal to obtain a filtered square wave signal; acquiring the current pulse period of the filtered square wave signal; and determining the speed signal of the traction motor based on the number of teeth on the gear disk and the current pulse period. This effectively suppresses the influence of electromagnetic interference on the accuracy of the speed signal and improves the accuracy of the speed signal. Specifically, a two-stage digital signal processing strategy can be used to solve the speed measurement problems caused by electromagnetic interference and gear disk errors respectively; it can improve the reliability and robustness of traction motor speed detection; and it can balance the speed measurement accuracy under high-speed and low-speed conditions as well as the speed measurement accuracy under complex electromagnetic interference environments. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0039] Figure 1 This is a first flowchart illustrating the speed signal processing method of the traction motor in an embodiment of this application;

[0040] Figure 2 This is a schematic diagram illustrating the relationship between a traction converter and a traction motor in existing technology.

[0041] Figure 3 This is a second flowchart illustrating the traction motor speed signal processing method in an embodiment of this application;

[0042] Figure 4 This is a third flowchart illustrating the traction motor speed signal processing method in the embodiments of this application;

[0043] Figure 5 This is a fourth flowchart illustrating the traction motor speed signal processing method in the embodiments of this application;

[0044] Figure 6 This is a flowchart illustrating the speed signal processing method of the traction motor in an application example of this application;

[0045] Figure 7 This is a schematic diagram illustrating the correspondence between time and electrical frequency before time threshold filtering, as exemplified in this application.

[0046] Figure 8This is a schematic diagram illustrating the correspondence between time and electrical frequency based on time threshold filtering, as exemplified in this application.

[0047] Figure 9 This is a schematic diagram illustrating the speed measurement effect of a deceleration hysteresis switching example in this application;

[0048] Figure 10 This is a schematic diagram illustrating the speed measurement effect of acceleration hysteresis switching in one example of this application;

[0049] Figure 11 This is a schematic diagram of the structure of the traction motor speed signal processing device in the embodiments of this application;

[0050] Figure 12 This is a schematic block diagram of the system configuration of an electronic device according to an embodiment of this application. Detailed Implementation

[0051] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0052] In actual operation, the speed measurement signal may also be subject to the following interferences:

[0053] Gear disk machining errors: Uneven gear tooth pitch or misaligned installation can cause periodic fluctuations in the square wave signal, especially at high speeds. Existing technologies typically use hardware filtering (such as RC filtering) or software filtering (such as moving average) to suppress interference, but it is difficult to simultaneously ensure speed measurement accuracy under both high-speed and low-speed conditions, as well as speed measurement precision in complex electromagnetic interference environments.

[0054] Based on this, in order to solve at least one of the problems existing in the prior art, this application proposes a method and apparatus for processing the speed signal of a traction motor, which relates to the field of locomotive and rolling stock traction control technology, and is particularly suitable for the traction motor speed measurement system of high-speed trains, subways and other rail transit vehicles, which can effectively suppress the influence of electromagnetic interference and gear disk machining errors on speed measurement accuracy.

[0055] The following examples illustrate this in detail.

[0056] To effectively suppress the impact of electromagnetic interference on the accuracy of speed signals and improve the precision of speed signals, this embodiment provides a method for processing the speed signals of a traction motor, wherein the execution subject is a speed signal processing device of the traction motor. Figure 1As shown, this method specifically includes the following:

[0057] Step 100: Obtain the square wave signal and gear tooth count corresponding to the traction motor.

[0058] Specifically, square wave signals collected by sensors on the motor shaft of the traction motor in the locomotive traction system can be obtained, and the gear disk can also be installed on the motor shaft. Figure 2 This is a schematic diagram showing the relationship between the traction converter 10 and the traction motor 20 in the prior art. Figure 2 In this context, TCU stands for Traction Control Unit, DSP stands for Digital Signal Processor, IOA stands for Input / Output Module, and X3 stands for the physical interface between the speed sensor and the Traction Control Unit.

[0059] Step 200: Based on the time interval between adjacent transition edges in the square wave signal, perform signal filtering on the square wave signal to obtain the filtered square wave signal.

[0060] Specifically, traditional speed signal calculation methods are based on an ideal speed square wave signal, calculating the time interval between two consecutive falling edges, and then calculating the motor frequency signal. Due to the complex electromagnetic environment of the traction system, the square wave signal output by the sensor may have instantaneous level jumps (such as glitches), leading to incorrect edge detection. To solve this problem in the existing technology, the square wave signal can be filtered based on a time threshold (i.e., a minimum effective level duration threshold) according to the time interval between adjacent jumping edges, resulting in a filtered square wave signal. Interference is filtered out by setting a time threshold. If the time interval between adjacent jumping edges is less than the time threshold, the jump is determined to be an interference signal and ignored; otherwise, it is recorded as a valid edge. By filtering out all interference signals in the square wave signal, the filtered square wave signal can be obtained.

[0061] Step 300: Obtain the current pulse period of the filtered square wave signal; determine the rotational speed signal of the traction motor based on the number of teeth on the gear disk and the current pulse period.

[0062] Specifically, based on the number of teeth on the gear disc and the current pulse period, an adaptive algorithm combining low-speed single-pulse speed measurement and high-speed multi-pulse speed measurement can be used, and hysteresis control and time smoothing can be employed to achieve bumpless switching, thereby determining the speed signal of the traction motor. The pulse period can be the time interval between two consecutive falling edges. The speed signal can represent the measured rotational speed. The current pulse period can represent the pulse period at the current moment.

[0063] To effectively reduce the impact of single tooth pitch errors, such as Figure 3As shown, in one embodiment, step 300, determining the rotational speed signal of the traction motor in the hysteresis interval based on the number of teeth on the gear disk and the current pulse period, includes:

[0064] Step 301: Determine the single-pulse rotational speed based on the number of teeth on the gear disk and the current pulse period.

[0065] Specifically, the single-pulse rotational speed n_low can be determined according to the following formula:

[0066] f1 = 1 / T

[0067] n_low = (60·f1) / Z

[0068] Where T is the current pulse period and Z is the number of teeth on the gear disk.

[0069] Step 302: Obtain the speed mode of the previous pulse cycle of the current pulse cycle. If the speed mode of the previous pulse cycle is a low speed mode, determine whether the single pulse speed is less than a preset first speed. If so, determine that the speed mode of the current pulse cycle is a low speed mode, and determine the single pulse speed as the speed signal of the traction motor in the current pulse cycle.

[0070] Specifically, the preset first speed can be a preset multiple of the maximum speed, and can be set according to actual conditions; this application does not impose any restrictions on this. Preferably, the preset first speed is 30.5% of the maximum speed. If the previous pulse cycle is in low-speed mode, and the single-pulse speed is less than 30.5% of the maximum speed, then the speed mode of the current pulse cycle remains the same as the previous pulse cycle; if the single-pulse speed is greater than or equal to 30.5% of the maximum speed, then the speed mode of the current pulse cycle can be switched to high-speed mode.

[0071] Specifically, the rotational speed mode of the previous pulse cycle can be determined in the same way. If the rotational speed mode of the previous pulse cycle corresponding to the previous pulse cycle is a low-speed mode, and the single-pulse rotational speed determined based on the number of teeth on the gear and the previous pulse cycle of the current pulse cycle is less than a preset first rotational speed, then the rotational speed mode of the previous pulse cycle of the current pulse cycle is a low-speed mode. If the rotational speed mode of the previous pulse cycle corresponding to the previous pulse cycle is a low-speed mode, and the single-pulse rotational speed determined based on the number of teeth on the gear and the previous pulse cycle of the current pulse cycle is greater than or equal to a preset first rotational speed, then the rotational speed mode of the previous pulse cycle of the current pulse cycle is a high-speed mode. If the single-pulse rotational speed corresponding to the initial pulse cycle is greater than or equal to the preset first rotational speed, then the initial (i.e., the starting) pulse cycle can be determined to be a high-speed mode. If the single-pulse rotational speed corresponding to the initial pulse cycle is less than a preset second rotational speed, then the initial pulse cycle can be determined to be a low-speed mode. The rotational speed mode corresponding to the initial pulse cycle can also be preset according to actual needs.

[0072] According to existing speed measurement methods, the impact of uneven gear tooth pitch increases with increasing motor speed. At low speeds, the impact of uneven gear tooth pitch on control performance is small. At high speeds, gear tooth pitch errors lead to increased deviations in speed acquisition, thus affecting the high-speed performance of the traction motor. To address the problem of uneven speed measurement caused by gear tooth machining errors, such as... Figure 4 As shown, in one embodiment, after determining whether the single-pulse rotation speed is less than a preset first rotation speed in step 302, the method further includes:

[0073] Step 303: If the single pulse speed is greater than or equal to the preset first speed, then the speed mode of the current pulse cycle is determined to be high-speed mode.

[0074] Step 304: Obtain multiple consecutive pulse cycles, and determine the rotational speed signal of the traction motor in the current pulse cycle based on the number of teeth of the gear disk and each pulse cycle. The number of pulse cycles is the same as the number of teeth of the gear disk.

[0075] Specifically, multiple consecutive pulse cycles can be obtained from the filtered square wave signal; these multiple consecutive pulse cycles can be multiple consecutive pulse cycles with the current pulse cycle as the first pulse cycle. When the speed mode of the current pulse cycle is high-speed mode, the speed signal n_high of the traction motor in the current pulse cycle can be determined according to the following formula:

[0076] f 2 = Z / T_Z

[0077] n_high = (60·f2) / Z

[0078] Where T_Z represents Z pulse cycles, and Z represents the number of teeth on the gear disk.

[0079] In order to achieve seamless switching between high-speed and low-speed rotation, in one embodiment, after step 303, the method further includes: using a time-smoothing switching method to switch the rotation speed signal of the previous pulse cycle to the rotation speed signal of the current pulse cycle.

[0080] Specifically, during the switching process, the traction motor's speed signal n_out is:

[0081] α(t) = 1 - t / T_s

[0082] f1 = 1 / T

[0083] n_low = (60·f1) / Z

[0084] f 2 = Z / T_Z

[0085] n_high = (60·f2) / Z

[0086] n_out = α(t) ×n_low + (1-α(t)) ×n_high.

[0087] Where t is time, T_s is the number of time beats, T is the previous pulse cycle, Z is the number of teeth on the gear disk, and T_Z is Z pulse cycles. t can represent the duration of the switching process.

[0088] For example, assuming the switching starts at T-5ms of the previous pulse cycle and completes at 5ms of the current pulse cycle, then the time frame can be determined to be 10ms. The rotational speed from the start of the previous pulse cycle to T-5ms can be n_low, the rotational speed signal from T-5ms of the previous pulse cycle to 5ms of the current pulse cycle can be n_out, and the rotational speed signal from 5ms of the current pulse cycle to the end can be n_high.

[0089] like Figure 5 As shown, in one embodiment, step 300, determining the rotational speed signal of the traction motor based on the number of teeth on the gear disc and the current pulse period, includes:

[0090] Step 311: Determine the single-pulse rotational speed based on the number of teeth on the gear disk and the current pulse period.

[0091] Specifically, the single-pulse rotational speed n_low can be determined according to the following formula:

[0092] f1 = 1 / T

[0093] n_low = (60·f1) / Z

[0094] Where T is the current pulse period and Z is the number of teeth on the gear disk.

[0095] Step 312: Obtain the rotation speed mode of the previous pulse cycle of the current pulse cycle. If the rotation speed mode of the previous pulse cycle is a high-speed mode, determine whether the single pulse rotation speed is greater than the preset second rotation speed. If so, determine that the rotation speed mode of the current pulse cycle is a high-speed mode.

[0096] Specifically, the preset second speed can be a preset multiple of the maximum speed, and can be set according to actual conditions; this application does not impose any restrictions on this. Preferably, the preset second speed is 29.5% of the maximum speed. The preset second speed is less than the preset first speed. The previous pulse cycle is in high-speed mode. If the single-pulse speed is greater than 29.5% of the maximum speed, the speed mode of the current pulse cycle remains the same as the speed mode of the previous pulse cycle. If the single-pulse speed is less than or equal to 29.5% of the maximum speed, the speed mode of the current pulse cycle can be switched to low-speed mode.

[0097] Specifically, the rotational speed mode of the previous pulse cycle can be determined in the same way. If the rotational speed mode of the previous pulse cycle corresponding to the previous pulse cycle is a high-speed mode, and the single-pulse rotational speed determined based on the number of teeth on the gear and the previous pulse cycle of the current pulse cycle is greater than a preset second rotational speed, then the rotational speed mode of the previous pulse cycle of the current pulse cycle is a high-speed mode. If the rotational speed mode of the previous pulse cycle corresponding to the previous pulse cycle is a high-speed mode, and the single-pulse rotational speed determined based on the number of teeth on the gear and the previous pulse cycle of the current pulse cycle is less than or equal to a preset second rotational speed, then the rotational speed mode of the previous pulse cycle of the current pulse cycle is a low-speed mode. If the single-pulse rotational speed corresponding to the initial pulse cycle is greater than or equal to a preset first rotational speed, then the initial pulse cycle can be determined to be a high-speed mode. If the single-pulse rotational speed corresponding to the initial pulse cycle is less than the preset second rotational speed, then the initial pulse cycle can be determined to be a low-speed mode. The rotational speed mode corresponding to the initial pulse cycle can also be preset according to actual needs.

[0098] Step 313: Obtain multiple consecutive pulse cycles, and determine the rotational speed signal of the traction motor in the current pulse cycle based on the number of teeth of the gear disk and each pulse cycle. The number of pulse cycles is the same as the number of teeth of the gear disk.

[0099] Specifically, the consecutive multiple pulse cycles can be multiple pulse cycles that are sequentially adjacent in time, with the current pulse cycle as the starting pulse cycle. When the speed mode of the current pulse cycle is high-speed mode, the speed signal n_high of the traction motor in the current pulse cycle can be determined according to the following formula:

[0100] f 2 = Z / T_Z

[0101] n_high = (60·f2) / Z

[0102] Where T_Z represents Z pulse cycles, and Z represents the number of teeth on the gear disk.

[0103] To effectively reduce the impact of single tooth pitch errors, in one embodiment, step 300, which involves determining the rotational speed signal of the traction motor based on the number of teeth on the gear disk and the current pulse period, further includes:

[0104] Step 314: If the single pulse speed is less than or equal to the preset second speed, then the speed mode of the current pulse cycle is determined to be the low speed mode, and the single pulse speed is determined as the speed signal of the traction motor in the current pulse cycle.

[0105] In one embodiment, after determining in step 314 that the rotational speed mode of the current pulse period is a low-speed mode, the method further includes:

[0106] A time-smoothing switching method is used to switch the speed signal of the previous pulse cycle to the speed signal of the current pulse cycle.

[0107] Specifically, during the switching process, the traction motor's speed signal n_out is:

[0108] α(t) = 1 - t / T_s

[0109] f1 = 1 / T

[0110] n_low = (60·f1) / Z

[0111] f 2 = Z / T_Z

[0112] n_high = (60·f2) / Z

[0113] n_out = α(t) ×n_low + (1-α(t)) ×n_high.

[0114] Where t is time, T_s is the number of time beats, T is the previous pulse cycle, Z is the number of teeth on the gear disk, and T_Z is Z pulse cycles. t can represent the duration of the switching process.

[0115] To further illustrate this solution, this application provides an application example of a traction motor speed signal processing method. In this application example, the method is specifically described as follows:

[0116] Step 1: Signal filtering based on time threshold (anti-electromagnetic interference).

[0117] Interference is filtered out by setting a minimum effective level duration threshold.

[0118] Threshold setting: Set the threshold according to the actual electromagnetic environment, that is, the minimum effective level duration threshold (typically 10μs). Only when the duration of high or low level exceeds this threshold is it considered a valid signal transition.

[0119] like Figure 6 As shown, the filtering process, i.e., step 1, includes:

[0120] Step 11: Detect the transition edges of the square wave signal, including the rising edge and the falling edge;

[0121] Step 12: Calculate the time interval Δt between adjacent transition edges;

[0122] Step 13: If Δt < threshold (e.g., 10μs), then it is determined to be an interference signal, and the jump is ignored;

[0123] Step 14: If Δt ≥ threshold, then record it as a valid edge.

[0124] Dynamic adjustment: The threshold can be dynamically adjusted according to the intensity of electromagnetic interference (e.g., 5μs~20μs) to optimize the filtering effect.

[0125] In one example, the correspondence between time and electrical frequency before time threshold filtering is as follows: Figure 7 As shown. In one example, the correspondence between time and electrical frequency based on time threshold filtering is as follows: Figure 8 As shown. Figure 7 and Figure 8 The horizontal axis represents time, and the vertical axis represents electrical frequency. The electrical frequency can be obtained by converting mechanical rotation speed (i.e., rotation speed signal).

[0126] Step 2: Adopt an adaptive speed measurement algorithm (anti-gear disk error).

[0127] An adaptive algorithm combining low-speed single-pulse speed measurement and high-speed multi-pulse speed measurement is employed, and bumpless switching is achieved through hysteresis control and time smoothing. For example... Figure 6 As shown, step 2 includes:

[0128] Step 21: If in low-speed mode, measure the time interval T between two consecutive falling edges. That is, low-speed mode single-pulse speed measurement:

[0129] Applicable conditions: Speed ​​< 29.5% of maximum speed; preferably, the maximum speed is 5000 rpm, corresponding to an electric frequency of 167 Hz for the two pole pairs.

[0130] Implementation method:

[0131] Measure the time interval T between two consecutive falling edges;

[0132] Step 22: Calculate the pulse frequency: f1 = 1 / T; convert to rotational speed: n_low = (60·f1) / Z, where Z is the number of teeth on the gear disc. Preferably, Z = 128.

[0133] Step 23: When n_low ≥ 30.5% of the maximum speed, switch to high-speed mode.

[0134] The advantages of steps 21 to 23 include: high time resolution at low speeds, which can effectively reduce the impact of single tooth pitch errors.

[0135] Step 24: If in high-speed mode, measure the time T_Z for Z complete pulse cycles. That is, high-speed mode Z-pulse velocity measurement:

[0136] Applicable conditions: Speed ​​≥ 30.5% of maximum speed;

[0137] Implementation method:

[0138] The time T_Z for measuring Z complete pulse cycles is used; Z is the number of teeth on the speed measuring gear disc in one revolution.

[0139] Step 25: Calculate the average frequency: f2 = Z / T_Z; convert to rotational speed: n_high = (60·f2) / Z = 60 / T_Z.

[0140] Step 26: When n_high ≤ 29.5% of the maximum speed, switch to low speed mode.

[0141] The advantages of steps 24 to 26 include: smoothing out the effects of uneven gear tooth pitch by multi-pulse averaging, thereby improving the stability of high-speed speed measurement.

[0142] Furthermore, to avoid frequent mode switching caused by speed fluctuations near the switching point, this application example can employ a strategy of hysteresis control and time-smooth switching:

[0143] Hysteresis range: Set the hysteresis range to 29.5%~30.5% of the maximum speed;

[0144] If the current mode is low speed, switch to high speed mode only when n_out = n_low ≥ 30.5%;

[0145] If the current mode is high speed, switch back to low speed mode only when n_out = n_high ≤ 29.5%.

[0146] Time smoothing: During the handover process, the transition is gradual using time steps (T_s = 10~200ms, with T_s = 10ms being preferred).

[0147] The weighting coefficient α changes linearly with time: α(t) = 1 - t / T_s;

[0148] The output speed is a mixed value: n_out = α·n_low + (1-α)·n_high;

[0149] After the transition is complete (t ≥ T_s), the system fully switches to the target mode. In one example, the speed measurement effect of the deceleration hysteresis switching is as follows: Figure 9 As shown. The speed measurement effect of accelerated hysteresis switching is as follows. Figure 10 As shown. Figure 9 and Figure 10 The horizontal axis represents time, and the vertical axis represents rotational speed.

[0150] From a software perspective, in order to effectively suppress the impact of electromagnetic interference on the accuracy of the speed signal and improve the precision of the speed signal, this application provides an embodiment of a traction motor speed signal processing device for implementing all or part of the speed signal processing method of the traction motor, see [link to embodiment]. Figure 11 The speed signal processing device for the traction motor specifically includes the following components:

[0151] The first acquisition module 01 is used to acquire the square wave signal and the number of teeth on the gear disk corresponding to the traction motor.

[0152] The filtering module 02 is used to filter the square wave signal according to the time interval between adjacent transition edges in the square wave signal to obtain the filtered square wave signal.

[0153] The second acquisition module 03 is used to acquire the current pulse period of the filtered square wave signal.

[0154] Processing module 04 is used to determine the rotational speed signal of the traction motor based on the number of teeth on the gear disk and the current pulse cycle.

[0155] The embodiments of the traction motor speed signal processing device provided in this specification can be used to execute the processing flow of the embodiments of the traction motor speed signal processing method described above. Its functions will not be repeated here, but can be referred to the detailed description of the embodiments of the traction motor speed signal processing method described above.

[0156] Figure 12 This is a schematic diagram of the physical structure of an electronic device provided in an embodiment of the present invention, such as... Figure 12 As shown, the electronic device includes: a memory 1201, a processor 1202, and a computer program stored in the memory 1201 and executable on the processor 1202. When the processor 1202 executes the computer program, it implements the following method:

[0157] Obtain the square wave signal and gear tooth count corresponding to the traction motor;

[0158] Based on the time interval between adjacent transition edges in the square wave signal, the square wave signal is filtered to obtain a filtered square wave signal.

[0159] Obtain the current pulse period of the filtered square wave signal; determine the rotational speed signal of the traction motor based on the number of teeth on the gear disk and the current pulse period.

[0160] This embodiment discloses a computer program product, which includes a computer program that, when executed by a processor, implements the following method:

[0161] Obtain the square wave signal and gear tooth count corresponding to the traction motor;

[0162] Based on the time interval between adjacent transition edges in the square wave signal, the square wave signal is filtered to obtain a filtered square wave signal.

[0163] Obtain the current pulse period of the filtered square wave signal; determine the rotational speed signal of the traction motor based on the number of teeth on the gear disk and the current pulse period.

[0164] This embodiment provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the following method:

[0165] Obtain the square wave signal and gear tooth count corresponding to the traction motor;

[0166] Based on the time interval between adjacent transition edges in the square wave signal, the square wave signal is filtered to obtain a filtered square wave signal.

[0167] Obtain the current pulse period of the filtered square wave signal; determine the rotational speed signal of the traction motor based on the number of teeth on the gear disk and the current pulse period.

[0168] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0169] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0170] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0171] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0172] In the description of this specification, the references to terms such as "an embodiment," "a specific embodiment," "some embodiments," "for example," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0173] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for processing the speed signal of a traction motor, characterized in that, include: Obtain the square wave signal and gear tooth count corresponding to the traction motor; Based on the time interval between adjacent transition edges in the square wave signal, the square wave signal is filtered to obtain a filtered square wave signal. Obtain the current pulse period of the filtered square wave signal; determine the rotational speed signal of the traction motor based on the number of teeth on the gear disk and the current pulse period.

2. The traction motor speed signal processing method according to claim 1, characterized in that, The step of determining the rotational speed signal of the traction motor based on the number of teeth on the gear disk and the current pulse period includes: The single-pulse rotational speed is determined based on the number of teeth on the gear disk and the current pulse period; The rotational speed mode of the previous pulse cycle is obtained. If the rotational speed mode of the previous pulse cycle is a low-speed mode, it is determined whether the single-pulse rotational speed is less than a preset first rotational speed. If so, the rotational speed mode of the current pulse cycle is determined to be a low-speed mode, and the single-pulse rotational speed is determined as the rotational speed signal of the traction motor in the current pulse cycle.

3. The traction motor speed signal processing method according to claim 2, characterized in that, After determining whether the single-pulse rotation speed is less than a preset first rotation speed, the method further includes: If the single pulse speed is greater than or equal to a preset first speed, then the speed mode of the current pulse cycle is determined to be high-speed mode; Multiple consecutive pulse cycles are acquired, and the rotational speed signal of the traction motor in the current pulse cycle is determined based on the number of teeth of the gear disk and each pulse cycle, wherein the number of pulse cycles is the same as the number of teeth of the gear disk.

4. The traction motor speed signal processing method according to claim 3, characterized in that, After determining that the rotation speed mode of the current pulse period is a high-speed mode, the method further includes: A time-smoothing switching method is used to switch the speed signal of the previous pulse cycle to the speed signal of the current pulse cycle.

5. The traction motor speed signal processing method according to claim 1, characterized in that, The step of determining the rotational speed signal of the traction motor based on the number of teeth on the gear disk and the current pulse period includes: The single-pulse rotational speed is determined based on the number of teeth on the gear disk and the current pulse period; Obtain the rotation speed mode of the previous pulse cycle of the current pulse cycle. If the rotation speed mode of the previous pulse cycle is a high-speed mode, determine whether the single pulse rotation speed is greater than a preset second rotation speed. If so, determine that the rotation speed mode of the current pulse cycle is a high-speed mode. Multiple consecutive pulse cycles are acquired, and the rotational speed signal of the traction motor in the current pulse cycle is determined based on the number of teeth of the gear disk and each pulse cycle, wherein the number of pulse cycles is the same as the number of teeth of the gear disk.

6. The traction motor speed signal processing method according to claim 5, characterized in that, After determining whether the single-pulse rotation speed is greater than a preset second rotation speed, the method further includes: If the single-pulse speed is less than or equal to the preset second speed, then the speed mode of the current pulse cycle is determined to be low speed mode, and the single-pulse speed is determined as the speed signal of the traction motor in the current pulse cycle.

7. The traction motor speed signal processing method according to claim 6, characterized in that, After determining that the rotational speed mode of the current pulse period is a low-speed mode, the method further includes: A time-smoothing switching method is used to switch the speed signal of the previous pulse cycle to the speed signal of the current pulse cycle.

8. A speed signal processing device for a traction motor, characterized in that, include: The first acquisition module is used to acquire the square wave signal and the number of teeth on the gear disk corresponding to the traction motor. The filtering module is used to filter the square wave signal according to the time interval between adjacent transition edges in the square wave signal to obtain the filtered square wave signal. The second acquisition module is used to acquire the current pulse period of the filtered square wave signal; The processing module is used to determine the rotational speed signal of the traction motor based on the number of teeth on the gear disk and the current pulse cycle.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the speed signal processing method for the traction motor according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the speed signal processing method for the traction motor according to any one of claims 1 to 7.

11. A computer program product, characterized in that, The computer program product includes a computer program that, when executed by a processor, implements the speed signal processing method for the traction motor according to any one of claims 1 to 7.

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