A method and system for identifying shift shock

Abstract

The application discloses a gear shift shock identification method and system, wherein a gear shift shock parameter corresponding to a time interval of each gear shift working condition is calculated according to an acceleration signal; a relationship between the gear shift shock parameter and a score under each gear shift working condition is obtained according to multiple gear shift shock parameters and the score corresponding to each gear shift working condition; a limit value of the gear shift shock parameter under each working condition is obtained according to a set score under each working condition and the relationship; and the limit value is used to identify whether a gear shift shock occurs under a current working condition. The technical scheme disclosed by the application avoids the influence of human factors, has a wide application range, can represent a gear shift shock level for different gear shift working conditions of different accelerators and gears, can quickly and batch-identify gear shift shock problems, and improves the efficiency of optimizing the gear shift shock.

Description

Technical Field

[0001] This invention belongs to the field of shift shock recognition technology, specifically relating to the recognition of shift shock in a dual-clutch transmission (DCT). Background Technology

[0002] Shift shock refers to the transient change in torque transmitted in the powertrain during normal driving and gear shifting, resulting in low-frequency vibrations in the vehicle. Shift shock is common in the development of dual-clutch transmissions (DCTs) for passenger vehicles. With the rapid development of the automotive industry, major domestic automakers are increasingly emphasizing drivability and comfort. Currently, the identification of shift shock issues in the automotive industry mainly relies on subjective evaluations by professionals. Optimization of shift shock issues primarily involves analyzing specific data after professional evaluators identify the problem and then implementing targeted optimizations. These traditional methods cannot achieve objective identification of shift shock issues on a large scale, nor can they enable rapid, large-scale optimization of shift shock problems. Summary of the Invention

[0003] To identify shift shocks in batches and quickly, this invention proposes a method and system for identifying shift shocks.

[0004] A method for identifying shift shock, one of the objectives of this invention, includes:

[0005] S1. Calculate the shifting impact parameters corresponding to each shifting condition based on the acceleration signal;

[0006] The shift interval is the time from the start of the shift operation to the end of the shift operation.

[0007] The method for identifying the shift interval includes: the start time of the shift condition is when the gear changes; the end time of the shift condition is when the engine speed and the transmission input shaft speed are synchronized.

[0008] The acceleration includes longitudinal acceleration signals collected in the shift range during the shifting condition and bandpass filtered to select bandpass acceleration in a specific frequency range; the specific frequency range is 2~20Hz.

[0009] The shift shock parameter is used to characterize the degree of impact of shift shock on the driving experience;

[0010] S2. Based on multiple shift impact parameters and the scores corresponding to each shift condition, obtain the relationship between the shift impact parameters and the scores for each shift condition;

[0011] The rating is an assessment of the impact of vibrations generated by the vehicle during the shifting period on drivability and comfort; the rating can be obtained by human perception or by sensing instruments.

[0012] S3. Based on the set score for each shift condition and the relationship, obtain the limit value of the shift shock parameter for each shift condition; the limit value is used to identify whether a shift shock occurs under the current condition.

[0013] Furthermore, the calculation method for the shift impact parameters includes:

[0014] Obtain the root mean square of multiple bandpass acceleration signals within the shift interval where the shift condition occurs;

[0015] The difference between the maximum and median of the moving root mean square of the plurality of bandpass acceleration signals is the shift impact parameter corresponding to the shift condition.

[0016] Furthermore, after step S3, the method further includes: if the shift shock parameter under the current shift condition exceeds the limit corresponding to the condition, then the moment when the maximum value of the shift shock parameter occurs is obtained; according to the stage of the shift process corresponding to that moment, corresponding optimization measures are taken to optimize the shift shock; the corresponding optimization measures include: when the moment is in the torque interaction stage, extending the clutch torque interaction time; when the moment is in the speed synchronization stage, extending the speed synchronization time.

[0017] A shift shock identification system for achieving the second objective of the present invention includes: a shift shock parameter calculation module, a relational formula acquisition module, and a shift shock identification module;

[0018] The shift shock parameter calculation module is used to calculate the shift shock parameters corresponding to each shift condition based on the bandpass acceleration signal.

[0019] The relation acquisition module is used to obtain the relation between the shift impact parameters and the score for each shift condition based on multiple shift impact parameters and the score corresponding to each shift condition.

[0020] The shift shock identification module is used to obtain the limit value of the shift shock parameter for each shift condition based on the set score for each shift condition and the relationship; the limit value is used to identify whether a shift shock occurs under the current condition.

[0021] Beneficial effects:

[0022] 1. The shifting impact identification method of the present invention avoids the influence of human factors compared with conventional subjective evaluation methods;

[0023] 2. It has a wide range of applications and can characterize the level of shift shock under different throttle and gear shifting conditions;

[0024] 3. It can quickly and in batches identify shift shock problems;

[0025] 4. Improved the efficiency of dual-clutch transmissions (DCTs) by optimizing shift shock issues. Attached Figure Description

[0026] Figure 1 This is a flowchart illustrating an embodiment of the method described in this invention;

[0027] Figure 2 This is a data acquisition diagram of a specific gear shifting condition according to an embodiment of the method described in this invention;

[0028] Figure 3 This is a schematic diagram of fitting the shifting impact parameters in an embodiment of the method described in this invention. Detailed Implementation

[0029] The following detailed embodiments are provided to explain the technical solutions of the claims of this invention, so that those skilled in the art can understand the claims. The scope of protection of this invention is not limited to the following specific embodiments. Any modifications made by those skilled in the art that incorporate the technical solutions of the claims but differ from the following detailed embodiments are also within the scope of protection of this invention.

[0030] Step 1: Vehicle Testing

[0031] Define the vehicle test conditions:

[0032] The test conditions take power upshifting as an example, including different gears and different throttle combinations, as shown in Table 1.

[0033]

[0034] Table 1 Vehicle Test Conditions Table

[0035] Equipment installation:

[0036] Data acquisition equipment and sensors were deployed. Accelerometers were installed on the driver's seat rail, and the vehicle test was conducted on a smooth asphalt road. Since the driving experience is primarily driven by changes in acceleration, longitudinal acceleration was collected to measure shift shock; the longitudinal direction is the same as the vehicle's forward direction.

[0037] The collected acceleration signal is synthesized from components of different frequencies. Since low-frequency components correspond to impact-related sensations such as shaking / jerking, and high-frequency components correspond to sensations such as trembling / numbness, in order to measure the impact on people, the longitudinal acceleration in the low-frequency range is selected to measure the impact of shifting.

[0038] Vehicle testing and recording:

[0039] The vehicle was tested according to the established test conditions. While collecting acceleration signals, relevant signals such as throttle, gear position, vehicle speed, engine speed, input shaft speed, torque and oil temperature were collected simultaneously, and the shift shock score results were recorded.

[0040] This embodiment objectively evaluates the shift shock level during the development of a certain vehicle model under a 60% throttle shift from 2nd to 3rd gear. Data collected through whole-vehicle testing under this 60% throttle shift from 2nd to 3rd gear condition is as follows: Figure 2 As shown, the data includes longitudinal acceleration, throttle, gear position, engine speed, input shafts 1 and 2 and engine speed, clutches 1 and 2 and engine torque. This data is used to identify relevant signals within the shift condition range and records the scoring result corresponding to that shift condition time range. In this embodiment, it is a score perceived by a human, where a... bp This is the filtered bandpass acceleration.

[0041] Step 2: Gear Shift Condition Identification

[0042] The shifting condition is identified by signals such as accelerator pedal opening, gear position, vehicle longitudinal acceleration, engine speed, and input shaft speed; that is, the start time of the shifting condition is when the gear changes. Figure 2 The shift from 2nd to 3rd gear, where the starting point is located, marks the start of the shift; the shift ends when the engine speed and the transmission input shaft speed synchronize. Figure 2 The location of the mid-End point is the end point of the shifting operation range.

[0043] Step 3, establish shift shock parameters

[0044] The longitudinal acceleration signal acquired under test conditions was bandpass filtered to remove the low-frequency components in the 2-20Hz range, thus obtaining the filtered bandpass acceleration a. bp ;

[0045] Shift shock parameters: bandpass acceleration signal a bp The degree to which the maximum value of the moving root mean square deviates from the median, such as Figure 2 As shown, the calculation method is given in the following formula:

[0046]

[0047] In the formula:

[0048] a bp (t) represents the time history of the 2-20Hz bandpass acceleration (m / s2);

[0049] t0: A sampling time (s) within the shifting operating range;

[0050] τ: The time width (s) for moving root mean square calculation, set according to actual needs; its further explanation is as follows:

[0051] τ is a given time interval. For example, to obtain the bandpass acceleration α at time t0. bp The moving root mean square of the t-axis is given, and τ is taken as 0.1s; then the bandpass acceleration a is taken as the time interval 0.1s before time t0. bp The bandpass acceleration 'a' during the time interval from t0-0.1s to t0 is obtained by integration. bp Integrating the square over time and dividing by time τ gives the mean. Taking the square root of the mean gives the moving root mean square value.

[0052] = That is, all bandpass acceleration signals a calculated within the shift interval. bp The maximum value of the moving root mean square.

[0053] = This refers to the multiple bandpass acceleration signals a calculated within the shift interval. bp The median of the moving root mean square.

[0054] Four test vehicles of a certain model were used. Each test vehicle was tested 5 times with 60% throttle shift from 2nd to 3rd gear. The impact evaluation parameters and scoring results of a total of 20 samples are summarized in Table 2.

[0055]

[0056] Table 2 Summary of Shift Impact Parameters and Scoring for 60% Throttle 2nd to 3rd Gear Upshift

[0057] Step 4: Fit the regression model

[0058] Will The values ​​correspond one-to-one with the test shift shock scores;

[0059] To fit a regression model to the test sample data, this embodiment uses a linear fitting method to obtain the regression model, which is then used to obtain... The relationship between the score and the final formula is used. To characterize the impact level; the regression model obtained by fitting the data from the 60% throttle shift from 2nd to 3rd gear is as follows: Figure 3 As shown.

[0060] Step 5: Determine the limits of shift shock parameters.

[0061] The test vehicle sample must consist of no fewer than 4 vehicles, and each test vehicle must be tested repeatedly under the same working condition more than 5 times.

[0062] Based on actual needs, a score is set for each shifting condition. Substituting this score into the fitted regression model for each shifting condition, the value of the shifting impact parameter corresponding to that score can be obtained. This value is the limit of the shifting impact parameter for each shifting condition.

[0063] Step 6, Shift shock recognition

[0064] The shift shock parameters calculated for each working condition represent the shift shock level of the corresponding working condition. It is determined whether the limit value is exceeded. If the limit value is exceeded, it is considered that there is a shift shock in the current working condition.

[0065] by Figure 3 For example, in a certain scenario where the throttle is at 60% and the vehicle is shifting from 3rd to 3rd gear, The value is 0.32 m / 2, which exceeds the limit of 0.21 m / 2, thus indicating that there is a shift shock.

[0066] Step 7, Optimize shift shock.

[0067] After identifying the shift shock problem, based on the shift shock parameters identified in step 5... The timing of the shift shock is determined by whether it occurs during the clutch torque interaction phase or the speed synchronization phase. Further optimization of shift shock can be achieved by extending the torque interaction time or the speed synchronization time.

[0068] The torque interaction stage refers to the stage in the clutch change process that transmits torque during the shifting process of a dual-clutch transmission (DCT).

[0069] The speed synchronization stage refers to the stage in the shifting process of a dual-clutch transmission (DCT) where the engine speed changes from one transmission input shaft to another.

[0070] Figure 3 In judgment The occurrence occurs during the torque interaction phase, thus extending the torque interaction time from 280ms to 336ms by 20%. Data is then collected again with the torque interaction time extended to 336ms, and the calculations are performed once more. The value is 0.19 m / s², which is less than the limit of 0.21 m / s², thus completing the impact optimization.

[0071] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0072] This application embodiment also provides a shift shock identification system, including: a shift shock parameter calculation module, a relational formula acquisition module, and a shift shock identification module;

[0073] The shift shock parameter calculation module is used to calculate the shift shock parameters corresponding to the time interval of each shift condition based on the acceleration signal.

[0074] The relation acquisition module is used to obtain the relation between the shift impact parameters and the score for each shift condition based on multiple shift impact parameters and the score corresponding to each shift condition.

[0075] The shift shock identification module is used to obtain the limit value of the shift shock parameter for each working condition based on the set score for each working condition and the relationship; the limit value is used to identify whether a shift shock occurs under the current working condition.

[0076] In another embodiment, an optimization module is also included, which is used to determine the stage of the transmission shifting process when the maximum value of the shifting impact parameter occurs when a shifting impact is identified, and to perform corresponding shifting impact optimization according to the stage.

[0077] When the transmission shifts during the torque interaction phase, the torque interaction time is extended to optimize shift shock.

[0078] When the transmission shifts during the speed synchronization phase, the speed synchronization time is extended to optimize shift shock.

[0079] When the transmission shifts during the torque interaction phase, the torque interaction time is extended to optimize shift shock.

[0080] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

Claims

1. A method for identifying shift shock, characterized in that, include: S1. Calculate the shifting impact parameters corresponding to each shifting condition based on the acceleration signal; S2. Based on multiple shift impact parameters and the scores corresponding to each shift condition, obtain the relationship between the shift impact parameters and the scores for each shift condition; S3. Based on the set score for each shifting condition and the relationship, obtain the limit value of the shifting shock parameter for each shifting condition; the limit value is used to identify whether a shifting shock occurs under the current condition; The acceleration includes longitudinal acceleration signals collected during gear shifting and bandpass filtered to select bandpass acceleration in a specific frequency range. The calculation method for the shift shock parameters includes: Obtain the root mean square of multiple bandpass acceleration signals within the shift interval where the shift condition occurs; The difference between the maximum and median of the moving root mean square of the plurality of bandpass acceleration signals is the shift shock parameter corresponding to the shift condition. The shift interval is the time from the start of the shift operation to the end of the shift operation. The method for identifying the shift interval includes: the start time of the shift condition is when the gear changes; the end time of the shift condition is when the engine speed and the transmission input shaft speed are synchronized. Step S3 is followed by: if the shift impact parameter under the current shift condition exceeds the limit corresponding to the condition, then the moment when the maximum value of the shift impact parameter occurs is obtained; according to the stage of the shift process at that moment, corresponding optimization measures are taken to optimize the shift impact; the corresponding optimization measures include: when the moment is in the torque interaction stage, extending the clutch torque interaction time; when the moment is in the speed synchronization stage, extending the speed synchronization time.

2. The method for identifying shift shock as described in claim 1, characterized in that, The specific frequency range is 2~20Hz.

3. A system for identifying shift shocks when performing the method of claim 1, characterized in that, It includes a shift shock parameter calculation module, a relation acquisition module, and a shift shock identification module; The shifting impact parameter calculation module is used to calculate the shifting impact parameters corresponding to each shifting condition based on the acceleration signal. The relation acquisition module is used to obtain the relation between the shift impact parameters and the score for each shift condition based on multiple shift impact parameters and the score corresponding to each shift condition. The shift shock identification module is used to obtain the limit value of the shift shock parameter under each shift condition based on the set score for each shift condition and the relationship; the limit value is used to identify whether a shift shock occurs under the current condition. It also includes an optimization shock module, which is used to determine the stage of the transmission shift process when the maximum value of the shift shock parameter occurs when the shift shock is detected, and to optimize the shift shock accordingly based on the stage. When the transmission shifts during the torque interaction phase, the torque interaction time is extended to optimize shift shock. When the transmission shifts during the speed synchronization phase, the speed synchronization time is extended to optimize shift shock.

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