Control method and device applied to electric vehicle gearbox and electric gearbox

Abstract

The application provides a control method and device applied to an electric vehicle gearbox and an electric gearbox, and relates to the technical field of vehicle control. The method comprises the following steps: acquiring an original speed signal output by a gearbox speed sensor, and generating speed fluctuation information by performing low-pass filtering processing on the original speed signal with different filtering coefficients multiple times; determining whether the current road working condition of the electric vehicle is a bad road working condition according to the speed fluctuation information, and controlling the gearbox to execute a shift inhibition strategy in the case that the current road working condition is determined to be a bad road working condition. The control method and device applied to the electric vehicle gearbox and the electric gearbox provided by the application are used for accurately identifying a bad road working condition and adopting a corresponding shift inhibition strategy, so that the hardware life of the electric gearbox is prolonged, and the probability of shift failure under a bad road working condition is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric vehicle control, and in particular to a control method and device applied to an electric vehicle gearbox and an electric gearbox. BACKGROUND

[0002] With the development of new energy technology and the popularization of new energy commercial vehicles, more and more users choose new energy vehicles as their first choice. The electric gearbox of the new energy vehicle uses an electric control electric system to drive the shifting actuator, which eliminates the need for complex energy supply devices and pipeline systems of pneumatic and hydraulic operating mechanisms, has the characteristics of simple structure, low cost, strong adaptability to environment, and small energy consumption, and has become an important development direction.

[0003] However, since the electric gearbox has no clutch, synchronizer and other sliding friction structures, the transmission system is rigidly connected, and the shifting process is completely dependent on the control of the shifting motor and the driving motor, therefore, under the bumpy road condition, the speed of the electric gearbox is subject to fluctuation, the request speed is always in a fluctuating state when the control motor speed is synchronized, which may lead to shifting failure or damage to the gearbox when hard shifting.

[0004] Therefore, there is an urgent need for a control method for the electric gearbox to reduce the probability of failure of the electric gearbox under the bumpy road condition. SUMMARY

[0005] The purpose of the present application is to provide a control method and device applied to an electric vehicle gearbox and an electric gearbox, which can accurately identify the bad road condition and take corresponding shifting inhibition strategy to improve the hardware life of the electric gearbox and reduce the probability of shifting failure under the bad road condition.

[0006] The present application provides a control method applied to an electric vehicle gearbox, comprising:

[0007] Obtaining an original speed signal output by a gearbox speed sensor, and generating speed fluctuation information by performing low-pass filtering processing on the original speed signal with different filtering coefficients; determining whether the current road condition of the electric vehicle is a bad road condition according to the speed fluctuation information, and controlling the gearbox to execute a shifting inhibition strategy in the case that the current road condition is determined to be a bad road condition; wherein the speed fluctuation information includes the speed fluctuation amount at each time; the bad road condition is used to indicate that the electric vehicle is on a bumpy road; and the shifting inhibition strategy is used to reduce the shifting frequency of the gearbox and increase the shifting timeout judgment time length of the gearbox.

[0008] Optionally, the generating the speed fluctuation information after the low-pass filtering of the original speed signal with different filter coefficients comprises: performing amplitude limiting filtering on the original speed signal to obtain an intermediate speed signal; performing low-pass filtering on the intermediate speed signal according to a first filter coefficient to obtain a first speed reference signal; and performing low-pass filtering on the first speed reference signal according to a second filter coefficient to obtain a second speed reference signal; wherein the second filter coefficient is smaller than the first filter coefficient.

[0009] Optionally, after the low-pass filtering of the first speed reference signal according to the second filter coefficient to obtain the second speed reference signal, the method further comprises: subtracting the first speed reference signal from the second speed reference signal to obtain a first deviation signal, and performing low-pass filtering on the first deviation signal according to a third filter coefficient to obtain a second deviation signal; superimposing the second speed reference signal and the second deviation signal to obtain a third speed reference signal, and subtracting the first speed reference signal from the third speed reference signal to obtain a third deviation signal; processing the third deviation signal according to a fourth filter coefficient to obtain an absolute value of the speed fluctuation at each time point, and generating the speed fluctuation information based on the absolute value of the speed fluctuation at each time point; wherein the third filter coefficient is smaller than the second filter coefficient; and the fourth filter coefficient is greater than the second filter coefficient.

[0010] Optionally, the determining whether the current road condition of the electric vehicle is a bad road condition according to the speed fluctuation information comprises: obtaining a speed reference value at any target time point based on the first speed parameter signal, and obtaining a speed fluctuation value at the target time point based on the speed fluctuation information; and determining that the road condition of the electric vehicle at the target time point is a bad road condition when the speed reference value is greater than a bad road identification limit value and the speed fluctuation value is greater than a first fluctuation limit value; wherein the bad road identification limit value is determined based on the minimum accuracy of the speed sensor.

[0011] Optionally, after obtaining the speed reference value at any target time point based on the first speed parameter signal and obtaining the speed fluctuation value at the target time point based on the speed fluctuation information, the method further comprises: not performing the bad road condition judgment when the speed reference value is less than or equal to the bad road identification limit value.

[0012] Optionally, after the speed reference value at any target time is obtained based on the first speed parameter signal, and the speed fluctuation value at the target time is obtained based on the speed fluctuation information, the method further comprises: in the case that the speed reference value is greater than the bad road identification limit value, the speed fluctuation value is less than a second fluctuation limit value, and the duration exceeds a preset judgment duration, determining that the road working condition of the electric vehicle at the target time is a non-bad road working condition; wherein the second fluctuation limit value is less than the first fluctuation limit value.

[0013] The application also provides a control device applied to a gearbox of an electric vehicle, comprising:

[0014] a signal acquisition module configured to acquire an original speed signal output by a gearbox speed sensor; a signal processing module configured to generate speed fluctuation information by performing low-pass filtering processing on the original speed signal with different filtering coefficients; a working condition judgment module configured to determine whether the current road working condition of the electric vehicle is a bad road working condition according to the speed fluctuation information; and a control module configured to control the gearbox to execute a shift suppression strategy in the case that the current road working condition is determined to be a bad road working condition; wherein the speed fluctuation information comprises a speed fluctuation amount at each time; the bad road working condition is used to indicate that the electric vehicle is on a bumpy road; and the shift suppression strategy is used to reduce the shift frequency of the gearbox and increase the shift timeout judgment duration of the gearbox.

[0015] Optionally, the signal processing module is specifically configured to perform amplitude limiting filtering processing on the original speed signal to obtain an intermediate speed signal; the signal processing module is specifically further configured to perform low-pass filtering processing on the intermediate speed signal according to a first filtering coefficient to obtain a first speed reference signal; and the signal processing module is specifically further configured to perform low-pass filtering processing on the first speed reference signal according to a second filtering coefficient to obtain a second speed reference signal; wherein the second filtering coefficient is less than the first filtering coefficient.

[0016] Optionally, the signal processing module is specifically configured to subtract the first rotation speed reference signal from the second rotation speed reference signal to obtain a first deviation signal, and perform low-pass filtering processing on the first deviation signal according to a third filter coefficient to obtain a second deviation signal; the signal processing module is specifically further configured to superimpose the second rotation speed reference signal and the second deviation signal to obtain a third rotation speed reference signal, and subtract the first rotation speed reference signal from the third rotation speed reference signal to obtain a third deviation signal; the signal processing module is specifically further configured to process the third deviation signal according to a fourth filter coefficient to obtain the absolute value of the rotation speed fluctuation at each moment, and generate the rotation speed fluctuation information based on the absolute value of the rotation speed fluctuation at each moment; wherein the third filter coefficient is less than the second filter coefficient; and the fourth filter coefficient is greater than the second filter coefficient.

[0017] Optionally, the acquisition module is further configured to acquire a rotation speed reference value at any target moment based on the first rotation speed parameter signal, and acquire a rotation speed fluctuation value at the target moment based on the rotation speed fluctuation information; and the working condition judgment module is specifically configured to determine that the road working condition of the electric vehicle at the target moment is a bad road working condition when the rotation speed reference value is greater than a bad road identification limit value and the rotation speed fluctuation value is greater than a first fluctuation limit value; wherein the bad road identification limit value is determined based on the minimum accuracy of the rotation speed sensor.

[0018] Optionally, the working condition judgment module is specifically configured to not perform bad road working condition judgment when the rotation speed reference value is less than or equal to the bad road identification limit value.

[0019] Optionally, the working condition judgment module is specifically configured to determine that the road working condition of the electric vehicle at the target moment is a non-bad road working condition when the rotation speed reference value is greater than the bad road identification limit value, the rotation speed fluctuation value is less than a second fluctuation limit value, and a duration exceeds a preset judgment duration; wherein the second fluctuation limit value is less than the first fluctuation limit value.

[0020] The application further provides a computer program product, which comprises computer programs / instructions, and the computer programs / instructions implement the steps of the control method for the transmission of the electric vehicle when executed by a processor.

[0021] The application further provides an electronic device, which comprises a memory, a processor, and computer programs stored in the memory and executable on the processor, and the processor implements the steps of the control method for the transmission of the electric vehicle when executing the programs.

[0022] The application also provides an electric gearbox, comprising a computer program / instruction, which, when executed by a processor, implements the steps of the control method for the electric vehicle gearbox according to any one of the above.

[0023] The application also provides an electric vehicle, wherein the electric gearbox described above is installed on the electric vehicle, and the control unit of the electric gearbox can execute the steps of the control method for the electric vehicle gearbox according to any one of the above.

[0024] The application also provides a computer readable storage medium, wherein a computer program is stored on the computer readable storage medium, and the computer program, when executed by a processor, implements the steps of the control method for the electric vehicle gearbox according to any one of the above.

[0025] The application provides a control method and device for an electric vehicle gearbox and an electric gearbox. First, an original speed signal collected by a gearbox speed sensor is obtained, and speed fluctuation information is generated by performing low-pass filtering on the original speed signal with different filtering coefficients. Then, whether the current road condition of the electric vehicle is a bad road condition is determined according to the speed fluctuation information. Finally, if it is determined that the current road condition is a bad road condition, the gearbox is controlled to execute a shift suppression strategy. The speed fluctuation information includes a speed fluctuation amount at each time point. The bad road condition is used to indicate that the electric vehicle is on a bumpy road. The shift suppression strategy is used to reduce the shift frequency of the gearbox and increase the shift timeout determination time length of the gearbox. In this way, the bad road condition can be accurately identified, and the corresponding shift suppression strategy can be adopted, which not only improves the hardware life of the electric gearbox, but also reduces the probability of shift failure in the bad road condition. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the application or the prior art, the drawings needed in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0027] Figure 1 is a flowchart of the control method for the electric vehicle gearbox provided by the application;

[0028] Figure 2 is a signal comparison and bad road condition determination schematic diagram provided by the application;

[0029] Figure 3 is a signal processing flowchart provided by the application;

[0030] Figure 4is a working condition judgment process schematic diagram provided by the present application;

[0031] Figure 5 is a structural schematic diagram of a control device applied to a gearbox of an electric vehicle provided by the present application;

[0032] Figure 6 is a structural schematic diagram of an electronic device provided by the present application. DETAILED DESCRIPTION

[0033] To make the objectives, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below with reference to the drawings in the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0034] The terms "first", "second" and the like in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than that illustrated or described herein, and the objects distinguished by "first", "second" and the like are generally of a kind and do not limit the number of objects, for example, the first object can be one or more. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / ", generally means that the front and rear associated objects are in an "or" relationship.

[0035] To solve the above technical problems in the related art, the embodiments of the present application provide a control method applied to a gearbox of an electric vehicle, which can identify a bad road condition based on a speed signal output by a speed sensor of the gearbox itself through a control unit of the electric gearbox, and execute a shift inhibition strategy in the case of identifying a bad road condition, so as to ensure the hardware life of the gearbox and simultaneously reduce the failure rate of shift failure.

[0036] The control method applied to a gearbox of an electric vehicle provided by the embodiments of the present application has the following advantages: 1. Low cost, bad road identification based on the speed sensor of the gearbox itself, without relying on other systems and without the need for additional sensors; 2. Higher accuracy and authenticity, bad road identification through the self-contained speed sensor, identification and control as a system, reducing the misjudgment rate; 3. High timeliness, capable of quickly identifying a bad road condition without the need for statistical values of multiple sampling points.

[0037] The application will be described in detail below with reference to the accompanying drawings and specific embodiments and application scenarios thereof.

[0038] As shown in Figure 1 The application provides a control method applied to an electric vehicle gearbox, which can include the following steps 101 to 103:

[0039] Step 101, obtaining an original speed signal output by a gearbox speed sensor, and generating speed fluctuation information by performing low-pass filtering processing on the original speed signal with different filtering coefficients.

[0040] The speed fluctuation information includes the speed fluctuation amount at each time point.

[0041] It should be noted that the control method applied to the electric vehicle gearbox in the application is executed by the control unit of the electric gearbox. That is, the electric gearbox capable of executing the control method applied to the electric vehicle gearbox in the application can realize the judgment of the bad road condition without relying on other systems and other sensors, and then execute the corresponding shift suppression strategy to protect the hardware of the gearbox.

[0042] Illustratively, the gearbox is an electric gearbox, which is different from the automated mechanical transmission (AMT) on the traditional fuel vehicle. The electric gearbox uses an electric control electric system to drive the shift actuator, which eliminates the complex energy supply device and pipeline system required by the pneumatic and hydraulic operating mechanism, has the characteristics of simple structure, low cost, strong adaptability to environment, small energy consumption, etc., and the electric gearbox has no sliding structure such as clutch and synchronizer, and the transmission system is rigidly connected, and the shift process is completely relied on the control of the shift motor and the driving motor.

[0043] Illustratively, the speed sensor is a speed sensor provided on the electric gearbox, which can feedback the speed value of the electric gearbox in real time.

[0044] Illustratively, after obtaining the original speed signal output by the speed sensor of the gearbox, the original speed signal can be processed to generate speed fluctuation information, and then the electric vehicle is judged whether it is in a bad road condition based on the speed fluctuation information.

[0045] Specifically, the specific steps of generating speed fluctuation information in step 101 can include the following steps 101a1 to 101a3:

[0046] Step 101a1, performing amplitude limiting filter processing on the original rotation speed signal to obtain an intermediate rotation speed signal.

[0047] Step 101a2, performing low-pass filter processing on the intermediate rotation speed signal according to a first filter coefficient to obtain a first rotation speed reference signal.

[0048] Step 101a3, performing low-pass filter processing on the first rotation speed reference signal according to a second filter coefficient to obtain a second rotation speed reference signal.

[0049] The second filter coefficient is less than the first filter coefficient.

[0050] It can be understood that the low-pass filter is a signal filtering method, which allows low-frequency signals to pass normally, while high-frequency signals exceeding the set threshold are blocked or weakened. However, the degree of blocking or weakening will change depending on different frequencies and different filter programs. It is also sometimes called high-cut filter or treble-cut filter. Generally, filter coefficients are used to adjust the proportion of low-pass filter or suppressed signals. The filter coefficient ranges from 0 to 1. The closer the filter coefficient is to 1, the weaker the filtering degree, and vice versa. The closer the filter coefficient is to 0, the stronger the filtering degree.

[0051] For example, the original rotation speed signal output by the rotation speed sensor is obviously disturbed by various disturbances, so it must be processed before use. The processing method includes: first, removing abnormal value jumps through an amplitude limiting filter, and then removing high-frequency burrs through a low-pass filter with a weak filtering degree (a larger filter coefficient, i.e. the first filter coefficient described above). After that, the processed rotation speed reference signal, i.e. the first rotation speed reference signal described above, can be obtained.

[0052] For example, the first rotation speed reference signal described above also needs to be filtered through a low-pass filter with a moderate filtering degree (i.e. the second filter coefficient described above) to filter out high-frequency fluctuations, and then a rotation speed reference signal with relatively stable fluctuations, i.e. the second rotation speed reference signal described above, is obtained.

[0053] However, due to the constant acceleration or constant deceleration stage of the vehicle, there is a nearly stable difference between the second rotation speed reference signal and the first rotation speed reference signal, and the size of the difference depends on the filtering strength. Therefore, after obtaining the first rotation speed reference signal and the second rotation speed reference signal, the difference needs to be calculated and recovered in the subsequent steps.

[0054] For example, as shown in FIG. 1, the original rotation speed signal is first processed through an amplitude limiting filter to obtain an intermediate rotation speed signal, and then the intermediate rotation speed signal is processed through a low-pass filter with a weak filtering degree (i.e. the first filter coefficient described above) to obtain a first rotation speed reference signal. Figure 2As shown in (A), there is a relatively stable difference between Spd_Fil_1 (i.e., the first rotational speed reference signal) and Spd_Fil_2 (i.e., the second rotational speed reference signal).

[0055] Specifically, after the step 101a3, the step 101 can further include the following steps 101b1 to 101b3:

[0056] In step 101b1, the first rotational speed reference signal is subtracted from the second rotational speed reference signal to obtain a first deviation signal, and low-pass filtering is performed on the first deviation signal according to a third filter coefficient to obtain a second deviation signal.

[0057] Exemplarily, the first deviation signal is used to indicate the difference between the first rotational speed reference signal and the second rotational speed reference signal. The third filter coefficient is smaller than the second filter coefficient.

[0058] In step 101b2, the second rotational speed reference signal is superimposed on the second deviation signal to obtain a third rotational speed reference signal, and the first rotational speed reference signal is subtracted from the third rotational speed reference signal to obtain a third deviation signal.

[0059] In step 101b3, the third deviation signal is processed according to a fourth filter coefficient to obtain the absolute value of the rotational speed fluctuation at each time point, and the rotational speed fluctuation information is generated based on the absolute value of the rotational speed fluctuation at each time point.

[0060] Exemplarily, the fourth filter coefficient is greater than the second filter coefficient, and the fourth filter coefficient can be the same as or different from the first filter coefficient.

[0061] Exemplarily, after obtaining the first deviation signal, low-pass filtering with a relatively strong filtering degree (i.e., the third filter coefficient) is required to obtain the second deviation signal. This calculation step is to calculate the deviation value between the first rotational speed reference signal and the second rotational speed reference signal due to the defects of the low-pass filter. The low-pass filtering with a relatively strong filtering degree is added here to ensure a constant deviation value and remove the fluctuation as much as possible.

[0062] Exemplarily, after obtaining the second deviation signal, the second rotational speed reference signal can be superimposed on the second deviation signal to compensate for the deviation value that is incorrectly filtered out during the constant acceleration and constant deceleration process, and then a stable value, i.e., the third rotational speed signal, is obtained.

[0063] For example, as shown in (A), the first rotational speed reference signal Spd_Fil_1 and the second rotational speed reference signal Spd_Fil_2 are subtracted to obtain a first deviation signal Spd_Fil_1-Spd_Fil_2. Figure 3As shown in (A), Spd_Fil_3 (i.e., the third speed signal mentioned above) and Spd_Fil_1 (i.e., the first speed signal mentioned above) only have a significant difference in the fluctuation phase (the time period contained in the vertical dashed line), and have almost no difference in the remaining working conditions.

[0064] Exemplarily, after obtaining the third speed signal mentioned above, the speed fluctuation information of the electric gearbox can be generated based on the third speed signal. Referring to Fig. 2, the speed fluctuation information of the electric gearbox is shown as Spd_BumpyVal. Figure 3 As shown in (B), Spd_BumpyVal is a curve for indicating the speed fluctuation value of the electric gearbox at each time.

[0065] Exemplarily, based on the speed fluctuation information of the electric gearbox, the current road working condition of the electric vehicle can be determined. Figure 2 As shown in (C), the current road working condition of the electric vehicle is shown as Spd_RoadCond. Figure 3 As shown in (C), the current road working condition of the electric vehicle is shown as Spd_RoadCond.

[0066] Firstly, the original speed signal Spd_Raw output by the speed sensor is obtained, and then first-order low-pass filtering (weak) and amplitude limiting filtering processing are performed on the Spd_Raw to output Spd_Fil_1, and first-order low-pass filtering (medium) processing is performed on the Spd_Fil_1 to output Spd_Fil_2. Then, Diff_1 (i.e., the first deviation signal mentioned above) is obtained by subtracting Spd_Fil_1 from Spd_Fil_2, and first-order low-pass filtering (strong) processing is performed on the Diff_1 to output Diff_Fil_1 (i.e., the second deviation signal mentioned above). Then, Spd_Fil_3 is obtained by superimposing Diff_Fil_1 and Spd_Fil_2, and Diff_2 (i.e., the third deviation signal mentioned above) is obtained by subtracting Spd_Fil_1 from Spd_Fil_3. Finally, first-order low-pass filtering (weak, i.e., the fourth filtering coefficient mentioned above) processing is performed on Diff_2, and the absolute value of the result is taken as the speed fluctuation amount of the electric gearbox, which is represented by Spd_BumpyVal.

[0067] The speed fluctuation information of the electric gearbox is used to determine whether the current road working condition of the electric vehicle is a bad road working condition, and if it is determined that the current road working condition is a bad road working condition, the gearbox is controlled to execute a shift suppression strategy.

[0068] Exemplarily, after obtaining the speed fluctuation information mentioned above, the bad road working condition can be identified based on the speed fluctuation information and the original speed signal.

[0069] Specifically, the step 102 can include the following step 102a1 and step 102a2:

[0070] The step 102a1 obtains a speed reference value at any target moment based on the first speed parameter signal, and obtains a speed fluctuation value at the target moment based on the speed fluctuation information.

[0071] The step 102a2 determines that the road condition of the electric vehicle at the target moment is a bad road condition when the speed reference value is greater than a bad road identification limit value and the speed fluctuation value is greater than a first fluctuation limit value.

[0072] The bad road identification limit value is determined based on the minimum accuracy of the speed sensor.

[0073] It should be noted that the steps 102a1 and 102a2 are for determining the bad road condition at any moment, that is, whether the road condition at any moment (including the current moment) is a bad road condition can be determined according to the method in the steps 102a1 and 102a2.

[0074] For example, the bad road identification limit value is defined based on the accuracy or resolution of the speed sensor and / or the target wheel system at ultra-low speed. The speed sensor acquisition system has a blind area, and the speed value collected in this area is not reliable, so the misjudgment in this stage needs to be excluded.

[0075] Based on this, after the step 102a1, the step 102 can further include the following step 102a3:

[0076] The step 102a3 does not determine the bad road condition when the speed reference value is less than or equal to the bad road identification limit value.

[0077] For example, when the gearbox speed value at the target moment is less than or equal to the bad road identification limit value, the bad road condition is not identified and determined to avoid misjudgment.

[0078] For example, when the gearbox speed value at the target moment is greater than the bad road identification limit value and the speed fluctuation value is greater than the first fluctuation limit value, it is determined that the road condition of the electric vehicle at the target moment is a bad road condition.

[0079] Specifically, after the step 102a1, the step 102 can further include the following step 102a4:

[0080] Step 102a4, in the case that the rotation speed reference value is greater than the bad road identification limit value, the rotation speed fluctuation value is less than the second fluctuation limit value, and the duration exceeds the preset judgment duration, it is determined that the road working condition of the electric vehicle at the target time is a non-bad road working condition.

[0081] The second fluctuation limit value is less than the first fluctuation limit value.

[0082] Exemplarily, when the gearbox rotation speed value at the target time is greater than the bad road identification limit value, the rotation speed fluctuation value is less than the second fluctuation limit value, and the duration exceeds the preset judgment duration, it can be determined that the road working condition of the electric vehicle at the target time is a non-bad road working condition.

[0083] Exemplarily, if the gearbox rotation speed value at the target time and the rotation speed fluctuation value satisfy other judgment conditions in addition to the judgment conditions in steps 102a1 to 102a4, the road working condition at the target time is consistent with the road working condition judgment result at the previous time.

[0084] It should be noted that the first fluctuation limit and the second fluctuation limit are both defined based on the fluctuation value that can be accepted by the normal control logic according to the real vehicle test data performance.

[0085] For example, as shown in Figure 4 When Spd_Fil_1≤limit 1 (i.e. the above-mentioned bad road identification limit value), no bad road working condition identification is performed, and at this time, the value of BumpySt used to represent the bad road working condition can be directly set to 0 (BumpySt=0 can also represent a non-bad road working condition). When Spd_Fil_1>limit 1 and Spd_BumpyVal>limit 2 (i.e. the above-mentioned first fluctuation limit value), BumpySt is set to 1, indicating that the current road working condition is a bad road working condition. When Spd_Fil_1>limit 1 and Spd_BumpyVal<limit 3 (i.e. the above-mentioned second fluctuation limit value), the counter Counter starts to perform accumulation calculation, and when the value of the counter exceeds a preset number T (i.e. the above-mentioned duration exceeds the preset judgment duration), BumpySt is set to 0, indicating that the current road working condition is a non-bad road working condition. When Spd_Fil_1>limit 1 and Spd_BumpyVal≥limit 3, the value of the counter is directly reset, and BumpySt is set to 0, indicating that the current road working condition is a non-bad road working condition.

[0086] Based on Figure 4 For example, as shown in Figure 3As shown in FIG. 6, when the rotation of the gearbox fluctuates and the judgment condition is met, the value of BumpySt is 1, indicating that the current road condition is a bad road condition; and when the value of the counter Counter exceeds the preset value, the value of BumpySt is 0, indicating that the current road condition is not a bad road condition.

[0087] Exemplarily, in the case of determining that the current road condition is a bad road condition, the shift suppression strategy can be executed to reduce the shift frequency of the gearbox and increase the shift timeout judgment time length of the gearbox, so as to reduce the probability of shift failure and protect the hardware of the gearbox to a certain extent and improve the hardware life of the gearbox.

[0088] The control method applied to the gearbox of the electric vehicle provided in the embodiments of the present application first acquires an original rotation speed signal collected by a gearbox rotation speed sensor, and generates rotation speed fluctuation information after performing low-pass filtering processing on the original rotation speed signal with different filtering coefficients for multiple times; then, whether the current road condition of the electric vehicle is a bad road condition is judged according to the rotation speed fluctuation information; finally, in the case of determining that the current road condition is a bad road condition, the gearbox is controlled to execute a shift suppression strategy. The rotation speed fluctuation information includes the rotation speed fluctuation amount at each moment; the bad road condition is used to indicate that the electric vehicle is on a bumpy road; and the shift suppression strategy is used to reduce the shift frequency of the gearbox and increase the shift timeout judgment time length of the gearbox. In this way, the bad road condition can be accurately identified, and the corresponding shift suppression strategy can be taken, which not only improves the hardware life of the electric gearbox, but also reduces the probability of shift failure under the bad road condition.

[0089] It should be noted that the control method applied to the gearbox of the electric vehicle provided in the embodiments of the present application can be a control device applied to the gearbox of the electric vehicle, or a control module in the control device applied to the gearbox of the electric vehicle for executing the control method applied to the gearbox of the electric vehicle. In the embodiments of the present application, the control device applied to the gearbox of the electric vehicle is taken as an example to illustrate the control device applied to the gearbox of the electric vehicle provided in the embodiments of the present application.

[0090] It should be noted that in the embodiments of the present application, the control method applied to the gearbox of the electric vehicle shown in each method figure is exemplarily illustrated by taking one of the figures in the embodiments of the present application as an example. In the specific implementation, the control method applied to the gearbox of the electric vehicle shown in each method figure can also be implemented by combining any other figure that can be combined in the above embodiments, which will not be described herein again.

[0091] The control device applied to the gearbox of the electric vehicle provided by the present application is described below, and the control method applied to the gearbox of the electric vehicle described below can be correspondingly referred to each other.

[0092] Figure 5 The structural schematic diagram of the control device applied to the gearbox of the electric vehicle provided by an embodiment of the present application is shown as Figure 5 specifically comprises:

[0093] The signal acquisition module 501 is configured to acquire an original speed signal output by a gearbox speed sensor; the signal processing module 502 is configured to generate speed fluctuation information by performing low-pass filtering processing on the original speed signal with different filtering coefficients multiple times; the working condition judgment module 503 is configured to determine whether the current road working condition of the electric vehicle is a bad road working condition according to the speed fluctuation information; and the control module 504 is configured to control the gearbox to perform a shift suppression strategy in the case where it is determined that the current road working condition is a bad road working condition; wherein the speed fluctuation information comprises a speed fluctuation amount at each time; the bad road working condition is used to indicate that the electric vehicle is on a bumpy road surface; and the shift suppression strategy is used to reduce the shift frequency of the gearbox and increase the shift timeout judgment time length of the gearbox.

[0094] Optionally, the signal processing module 502 is specifically configured to perform amplitude limiting filtering processing on the original speed signal to obtain an intermediate speed signal; the signal processing module 502 is specifically further configured to perform low-pass filtering processing on the intermediate speed signal according to a first filtering coefficient to obtain a first speed reference signal; the signal processing module 502 is specifically further configured to perform low-pass filtering processing on the first speed reference signal according to a second filtering coefficient to obtain a second speed reference signal; and the second filtering coefficient is less than the first filtering coefficient.

[0095] Optionally, the signal processing module 502 is specifically configured to subtract the first speed reference signal from the second speed reference signal to obtain a first deviation signal, and perform low-pass filtering processing on the first deviation signal according to a third filtering coefficient to obtain a second deviation signal; the signal processing module 502 is specifically further configured to superimpose the second speed reference signal and the second deviation signal to obtain a third speed reference signal, and subtract the first speed reference signal from the third speed reference signal to obtain a third deviation signal; the signal processing module 502 is specifically further configured to process the third deviation signal according to a fourth filtering coefficient to obtain an absolute value of the speed fluctuation amount at each time, and generate the speed fluctuation information based on the absolute value of the speed fluctuation amount at each time; wherein the third filtering coefficient is less than the second filtering coefficient; and the fourth filtering coefficient is greater than the second filtering coefficient.

[0096] Optionally, the acquisition module is further configured to acquire a speed reference value at any target moment based on the first speed parameter signal, and acquire a speed fluctuation value at the target moment based on the speed fluctuation information; and the working condition judging module 503 is specifically configured to determine that the road working condition of the electric vehicle at the target moment is a bad road working condition when the speed reference value is greater than a bad road identification limit value and the speed fluctuation value is greater than a first fluctuation limit value; wherein the bad road identification limit value is determined based on the minimum accuracy of the speed sensor.

[0097] Optionally, the working condition judging module 503 is specifically configured to not perform bad road working condition judgment when the speed reference value is less than or equal to the bad road identification limit value.

[0098] Optionally, the working condition judging module 503 is specifically configured to determine that the road working condition of the electric vehicle at the target moment is a non-bad road working condition when the speed reference value is greater than the bad road identification limit value, the speed fluctuation value is less than a second fluctuation limit value, and the duration exceeds a preset judgment duration; wherein the second fluctuation limit value is less than the first fluctuation limit value.

[0099] The application provides a control device applied to a gearbox of an electric vehicle. First, an original speed signal collected by a gearbox speed sensor is acquired, and speed fluctuation information is generated after performing low-pass filtering processing on the original speed signal with different filtering coefficients multiple times. Then, whether the current road working condition of the electric vehicle is a bad road working condition is determined according to the speed fluctuation information. Finally, when it is determined that the current road working condition is a bad road working condition, the gearbox is controlled to perform a shift suppression strategy. The speed fluctuation information includes a speed fluctuation amount at each moment. The bad road working condition is used to indicate that the electric vehicle is on a bumpy road. The shift suppression strategy is used to reduce the shift frequency of the gearbox and increase the shift timeout judgment duration of the gearbox. In this way, the bad road working condition can be accurately identified, and the corresponding shift suppression strategy can be taken, which not only improves the hardware life of the electric gearbox, but also reduces the probability of shift failure under the bad road working condition.

[0100] Figure 6 An example of an electronic device is shown in the physical structure diagram as follows: Figure 6As shown, the electronic device can include a processor 610, a communications interface 620, a memory 630, and a communications bus 640, wherein the processor 610, the communications interface 620, and the memory 630 complete mutual communication through the communications bus 640. The processor 610 can invoke a logical instruction in the memory 630 to execute a control method applied to an electric vehicle transmission, the method including: acquiring an original speed signal output by a transmission speed sensor, and generating speed fluctuation information by performing low-pass filtering processing on the original speed signal with different filtering coefficients; determining whether the current road condition of the electric vehicle is a bad road condition according to the speed fluctuation information, and controlling the transmission to execute a shift suppression strategy in a case where it is determined that the current road condition is a bad road condition; wherein the speed fluctuation information includes a speed fluctuation amount at each time; the bad road condition is used to indicate that the electric vehicle is on a bumpy road; and the shift suppression strategy is used to reduce the shift frequency of the transmission and increase the shift timeout judgment time length of the transmission.

[0101] In addition, the logical instruction in the memory 630 described above can be implemented in the form of a software functional unit and sold or used as an independent product, and can be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the present application essentially or the part that contributes to the prior art or part of the technical solutions can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the methods described in the various embodiments of the present application. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various program code storage media.

[0102] In another aspect, the present application also provides a computer program product, which comprises a computer program stored on a computer readable storage medium, the computer program comprising program instructions which, when executed by a computer, enable the computer to perform the control method for a transmission of an electric vehicle provided by any of the above methods, the method comprising: obtaining an original speed signal output by a transmission speed sensor, and generating speed fluctuation information by performing low-pass filtering on the original speed signal multiple times with different filter coefficients; determining whether a current road condition of the electric vehicle is a bad road condition according to the speed fluctuation information, and controlling the transmission to execute a shift suppression strategy if it is determined that the current road condition is the bad road condition; wherein the speed fluctuation information comprises a speed fluctuation amount at each time; the bad road condition is used to indicate that the electric vehicle is on a bumpy road; and the shift suppression strategy is used to reduce a shift frequency of the transmission and increase a shift timeout determination duration of the transmission.

[0103] In yet another aspect, the present application also provides a computer readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the control method for a transmission of an electric vehicle provided by any of the above methods, the method comprising: obtaining an original speed signal output by a transmission speed sensor, and generating speed fluctuation information by performing low-pass filtering on the original speed signal multiple times with different filter coefficients; determining whether a current road condition of the electric vehicle is a bad road condition according to the speed fluctuation information, and controlling the transmission to execute a shift suppression strategy if it is determined that the current road condition is the bad road condition; wherein the speed fluctuation information comprises a speed fluctuation amount at each time; the bad road condition is used to indicate that the electric vehicle is on a bumpy road; and the shift suppression strategy is used to reduce a shift frequency of the transmission and increase a shift timeout determination duration of the transmission.

[0104] In yet another aspect, the present application also provides an electric transmission comprising a computer program / instructions, which, when executed by a processor, performs the control method for a transmission of an electric vehicle according to the steps of any of the above methods, the method comprising: obtaining an original speed signal output by a transmission speed sensor, and generating speed fluctuation information by performing low-pass filtering on the original speed signal multiple times with different filter coefficients; determining whether a current road condition of the electric vehicle is a bad road condition according to the speed fluctuation information, and controlling the transmission to execute a shift suppression strategy if it is determined that the current road condition is the bad road condition; wherein the speed fluctuation information comprises a speed fluctuation amount at each time; the bad road condition is used to indicate that the electric vehicle is on a bumpy road; and the shift suppression strategy is used to reduce a shift frequency of the transmission and increase a shift timeout determination duration of the transmission.

[0105] The device embodiments described above are merely illustrative, wherein the units described as separate components can or can not be physically separate, and the components displayed as units can or can not be physical units, i.e., can be located in one place, or can be distributed to multiple network units. Part or all of the modules can be selected to achieve the purposes of the embodiments according to actual needs. Those skilled in the art can understand and implement without creative labor.

[0106] Through the description of the above embodiments, those skilled in the art can clearly understand that the embodiments can be realized by means of software and necessary universal hardware platforms, and of course can also be realized by hardware. Based on such understanding, the above technical solutions can be embodied in the form of software products, and the computer software products can be stored in a computer readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and include a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute the methods described in each embodiment or some parts of the embodiments.

[0107] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A control method applied to an electric vehicle transmission, characterized by, The method is applied to an electric vehicle, and comprises: obtaining an original speed signal output by a gearbox speed sensor, and generating speed fluctuation information by performing low-pass filtering on the original speed signal multiple times with different filtering coefficients; determining whether a current road condition of the electric vehicle is a bad road condition according to the speed fluctuation information, and controlling the gearbox to execute a shift suppression strategy in a case where it is determined that the current road condition is the bad road condition; wherein the speed fluctuation information comprises a speed fluctuation amount at each time point; the bad road condition is used to indicate that the electric vehicle is on a bumpy road; and the shift suppression strategy is used to reduce a shift frequency of the gearbox and increase a shift timeout determination time length of the gearbox; the generation of the speed fluctuation information by performing low-pass filtering on the original speed signal multiple times with different filtering coefficients comprises: performing amplitude limiting filtering on the original speed signal to obtain an intermediate speed signal; performing low-pass filtering on the intermediate speed signal according to a first filtering coefficient to obtain a first speed reference signal; performing low-pass filtering on the first speed reference signal according to a second filtering coefficient to obtain a second speed reference signal; wherein the second filtering coefficient is smaller than the first filtering coefficient; subtracting the first speed reference signal from the second speed reference signal to obtain a first deviation signal, and performing low-pass filtering on the first deviation signal according to a third filtering coefficient to obtain a second deviation signal; superimposing the second speed reference signal and the second deviation signal to obtain a third speed reference signal, and subtracting the first speed reference signal from the third speed reference signal to obtain a third deviation signal; processing the third deviation signal according to a fourth filtering coefficient to obtain an absolute value of the speed fluctuation amount at each time point, and generating the speed fluctuation information based on the absolute value of the speed fluctuation amount at each time point; wherein the third filtering coefficient is smaller than the second filtering coefficient, and the fourth filtering coefficient is greater than the second filtering coefficient.

2. The method of claim 1, wherein, the determination of whether the current road condition of the electric vehicle is the bad road condition according to the speed fluctuation information comprises: obtaining a speed reference value at any target time point based on the first speed parameter signal, and obtaining a speed fluctuation value at the target time point based on the speed fluctuation information; determining that the road condition of the electric vehicle at the target time point is the bad road condition in a case where the speed reference value is greater than a bad road identification limit value and the speed fluctuation value is greater than a first fluctuation limit value; wherein the bad road identification limit value is determined based on a minimum accuracy of the speed sensor.

3. The method of claim 2, wherein, after the obtaining of the speed reference value at any target time point based on the first speed parameter signal and the obtaining of the speed fluctuation value at the target time point based on the speed fluctuation information, the method further comprises: not performing the determination of the bad road condition in a case where the speed reference value is less than or equal to the bad road identification limit value.

4. The method of claim 2, wherein, After the speed reference value at any target moment is obtained based on the first speed parameter signal and the speed fluctuation value at the target moment is obtained based on the speed fluctuation information, the method further comprises: In a case where the speed reference value is greater than the bad road identification limit value, the speed fluctuation value is less than a second fluctuation limit value, and a duration exceeds a preset judgment duration, it is determined that the road working condition of the electric vehicle at the target moment is a non-bad road working condition; The second fluctuation limit value is less than the first fluctuation limit value.

5. A control device applied to a transmission of an electric vehicle, characterized by, The device is applied to an electric vehicle and comprises: A signal acquisition module configured to acquire an original speed signal output by a gearbox speed sensor; A signal processing module configured to generate speed fluctuation information by performing low-pass filtering processing on the original speed signal with different filtering coefficients multiple times; A working condition judgment module configured to determine whether the current road working condition of the electric vehicle is a bad road working condition according to the speed fluctuation information; A control module configured to control the gearbox to execute a shift suppression strategy in a case where it is determined that the current road working condition is a bad road working condition; The speed fluctuation information comprises a speed fluctuation amount at each moment; the bad road working condition is used to indicate that the electric vehicle is on a bumpy road; and the shift suppression strategy is used to reduce the shift frequency of the gearbox and increase the shift timeout judgment duration of the gearbox; The signal processing module is specifically configured to perform amplitude limiting filtering processing on the original speed signal to obtain an intermediate speed signal; The signal processing module is specifically configured to perform low-pass filtering processing on the intermediate speed signal according to a first filtering coefficient to obtain a first speed reference signal; The signal processing module is specifically configured to perform low-pass filtering processing on the first speed reference signal according to a second filtering coefficient to obtain a second speed reference signal; The second filtering coefficient is less than the first filtering coefficient; The signal processing module is specifically configured to subtract the first speed reference signal from the second speed reference signal to obtain a first deviation signal, and perform low-pass filtering processing on the first deviation signal according to a third filtering coefficient to obtain a second deviation signal; The signal processing module is specifically configured to superimpose the second speed reference signal and the second deviation signal to obtain a third speed reference signal, and subtract the first speed reference signal from the third speed reference signal to obtain a third deviation signal; The signal processing module is specifically configured to process the third deviation signal according to a fourth filtering coefficient to obtain an absolute value of the speed fluctuation amount at each moment, and generate the speed fluctuation information based on the absolute value of the speed fluctuation amount at each moment; The third filtering coefficient is less than the second filtering coefficient; and the fourth filtering coefficient is greater than the second filtering coefficient.

6. An electric gearbox, characterized in that The computer program / instructions are executed by a processor to perform the steps of the control method applied to a gearbox of an electric vehicle according to any one of claims 1 to 4.

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