A slope calculation correction method based on vehicle driving on a rotating hub

Abstract

The application provides a slope calculation correction method based on vehicle driving on a rotating hub, relates to the technical field of slope calculation correction, and comprises the following steps: monitoring vehicle driving state to obtain vehicle information, wherein the vehicle information comprises vehicle CAN bus signals and sensor signals; confirming vehicle driving conditions according to the vehicle CAN bus signals, confirming vehicle rotating hub mode according to the vehicle driving conditions and in combination with the vehicle information, and activating slope calculation correction according to the vehicle rotating hub mode; judging whether the corrected vehicle information meets preset conditions in combination with the vehicle driving conditions; if yes, exiting the current vehicle rotating hub mode and entering normal control, and returning to the step of confirming vehicle driving conditions according to the vehicle CAN bus signals; and if no, continuing to execute the current vehicle rotating hub mode. The application identifies whether the vehicle is in the special state of driving on a rotating hub by monitoring the vehicle information, and then corrects the slope calculation logic and the fault error logic of the gearbox controller.

Description

Technical Field

[0001] This invention relates to the field of slope calculation and correction technology, and in particular to a slope calculation and correction method based on a vehicle traveling on a turn wheel. Background Technology

[0002] The wheel swivel test is a test method that involves placing the vehicle under test on two or four wheel swivels to conduct test items. It is one of the commonly used operating conditions in the development and acceptance phases of automobiles. Figure 1 As shown. Even after a new model is launched, the vehicle will still face random emissions and fuel consumption tests on a rotating platform. Therefore, ensuring that the vehicle is controlled identically when running on a rotating platform and when driving on a flat road is a problem that the transmission software or other main control units must address, and it is also a basic requirement of automotive industry laws and regulations.

[0003] Without a special control strategy to handle the driving conditions of the vehicle on the turntable, even if the vehicle is simulating a flat road driving condition on the turntable, the transmission controller will mistakenly trigger the slope calculation when the vehicle accelerates or decelerates, causing the shift logic to enter the slope mode, which in turn deviates from the actual test conditions, resulting in problems such as shift line deviation, intelligent start-stop failure, and abnormal slope signal calculation.

[0004] Currently, to meet the requirements of wheel spin tests, most manufacturers typically manually disconnect the wheel speed sensors or ESP controllers of the ESP (Electronic Stability Program) system. This forces the vehicle's wheel speed and acceleration sensor signals to report errors, thereby disabling the control software's hill-start calculations. However, manually disconnecting the ESP wheel speed sensors or ESP controllers to meet wheel spin test requirements is not only complex and lacks intelligence, but also fails to comply with relevant regulations. Summary of the Invention

[0005] Therefore, the purpose of this invention is to provide a slope calculation and correction method based on vehicle driving in a rotating wheel, which solves the technical problems of the existing method of manually disconnecting the wheel speed sensor or ESP controller of ESP to cope with the rotating wheel test. On the one hand, the operation is complicated and not intelligent enough; on the other hand, it does not meet the requirements of relevant regulations.

[0006] This invention provides a slope calculation and correction method based on a vehicle's driving in a rotating wheel, applied to a vehicle's transmission control unit. The correction method includes:

[0007] The vehicle's driving status is monitored to obtain vehicle information, which includes vehicle CAN bus signals and sensor signals. The vehicle CAN bus signals include vehicle speed, front wheel speed, rear wheel speed, and steering wheel angle. The sensor signals include vehicle longitudinal acceleration and vehicle lateral acceleration.

[0008] The vehicle's driving condition is confirmed based on the vehicle's CAN bus signal. The vehicle's driving condition includes four-wheel driving condition and non-four-wheel driving condition. Based on the vehicle's driving condition and combined with the vehicle's information, the vehicle's wheel rotation mode is confirmed. The vehicle's wheel rotation mode includes four-wheel drive wheel rotation mode and two-wheel drive wheel rotation mode. Based on the vehicle's wheel rotation mode, the slope calculation and correction are activated. The slope calculation and correction includes correcting the slope to 0 and disabling slip control, hill shift line correction, and wheel speed signal fault diagnosis to ensure that the vehicle's driving condition is consistent with that of a normal flat road surface.

[0009] Based on the vehicle's driving conditions, determine whether the corrected vehicle information meets the preset conditions.

[0010] If the corrected vehicle information meets the preset conditions, the current vehicle swivel mode will be exited and normal control will be entered. The process will then return to the step of confirming the vehicle's driving condition based on the vehicle's CAN bus signal.

[0011] If the corrected vehicle information does not meet the preset conditions, the current vehicle rotation mode will continue to be executed.

[0012] The aforementioned slope calculation and correction method based on vehicle rotation monitoring identifies whether the vehicle is in a special state of rotation by monitoring overall vehicle information, thereby correcting the slope calculation logic and the fault reporting logic of the transmission controller. Specifically, the technical solution of this application is integrated into the transmission control unit. By acquiring signals such as actual vehicle speed, front wheel speed, rear wheel speed, vehicle posture, and steering wheel angle, it determines the driving conditions of the vehicle, correctly handles slope calculation and front and rear wheel slippage, and ensures that the vehicle's operating strategy is no different from that of actual flat road driving. The slope calculation and correction method based on vehicle rotation provided in this application does not require manual disconnection of the ESP wheel speed sensors or ESP controller to cope with the rotation test, has a high degree of intelligence, and complies with relevant regulations.

[0013] In addition, the slope calculation and correction method based on vehicle driving on a turntable according to the present invention may also have the following additional technical features:

[0014] Furthermore, the steps of confirming the vehicle's driving condition based on the vehicle's CAN bus signal, confirming the vehicle's wheel-turning mode based on the vehicle's driving condition and combined with the vehicle's information, and activating the slope calculation and correction based on the vehicle's wheel-turning mode include:

[0015] Determine whether the vehicle is in a four-wheel driving condition based on the vehicle's CAN bus signal;

[0016] If the vehicle is in four-wheel driving mode, determine whether it is in four-wheel drive hub mode based on the vehicle information.

[0017] If it is in four-wheel drive hub mode, then slope calculation correction will be activated;

[0018] If the vehicle is not in a four-wheel driving condition, determine whether the vehicle is in two-wheel drive mode based on the vehicle information.

[0019] If it is a two-wheel drive hub mode, then the slope calculation correction will be activated.

[0020] Furthermore, in the step of determining whether a vehicle is in four-wheel drive hub mode based on the vehicle information, the criteria for determining four-wheel drive hub mode include:

[0021]

[0022] Wherein, acceleration difference = actual vehicle acceleration - longitudinal acceleration of the vehicle body, actual vehicle acceleration = dv / dt, where v is velocity and t is time.

[0023] Furthermore, in the step of determining whether a vehicle is in two-wheel drive mode based on the vehicle information, the criteria for determining two-wheel drive mode include:

[0024]

[0025] Furthermore, in the step of determining whether the corrected vehicle information meets preset conditions based on the vehicle's driving conditions; if the corrected vehicle information meets the preset conditions, then exiting the current vehicle steering mode and entering normal control, the preset conditions are as follows when the vehicle's driving condition is a four-wheel driving condition:

[0026] |Front wheel speed - Rear wheel speed| > Second preset wheel speed difference threshold, or vehicle longitudinal acceleration > First acceleration threshold, or vehicle lateral acceleration > Second acceleration threshold, and or steering wheel angle > First steering angle threshold.

[0027] Furthermore, in the step of determining whether the corrected vehicle information meets preset conditions based on the vehicle's driving conditions; if the corrected vehicle information meets the preset conditions, then exiting the current vehicle steering mode and entering normal control, the preset conditions are as follows when the vehicle's driving conditions are not four-wheel driving conditions:

[0028] The front wheel speed is greater than the first preset wheel speed threshold, and the rear wheel speed is greater than the first preset wheel speed threshold, or the longitudinal acceleration of the vehicle body is greater than the first acceleration threshold, or the lateral acceleration of the vehicle body is greater than the second acceleration threshold, or the steering wheel angle is greater than the first steering angle threshold. Attached Figure Description

[0029] Figure 1 This is a schematic diagram illustrating the test conditions for simulating flat road driving on a two-wheel drive hub / four-wheel drive hub according to the present invention.

[0030] Figure 2 This is a flowchart of the slope calculation and correction method for a vehicle traveling on a rotating wheel, as described in this invention.

[0031] Figure 3 Test data for existing technologies that lack slope correction functionality;

[0032] Figure 4 This is the test data for the slope correction function of this invention;

[0033] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0034] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Several embodiments of the invention are illustrated in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0036] To address the technical problem of inconsistent speed changes with actual acceleration / deceleration sensor readings when a vehicle is driving on a rotating platform, leading to abnormal slope calculations, this application monitors the vehicle's overall information to identify whether the vehicle is in a special state of driving on a rotating platform. This allows for the correction of the slope calculation logic and the fault reporting logic of the transmission controller. Specifically, the technical solution of this application is integrated into the transmission control unit. By acquiring signals such as actual vehicle speed, front wheel speed, rear wheel speed, vehicle posture, and steering wheel angle, it determines the vehicle's driving conditions, correctly handles slope calculations and front / rear wheel slippage, and ensures that the vehicle's operating strategy is indistinguishable from that of actual flat road driving.

[0037] To facilitate understanding of the present invention, several embodiments are given below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of the present invention will be more thorough and complete.

[0038] Example 1

[0039] Please see Figure 2 The diagram illustrates a slope calculation and correction method based on vehicle driving on a rotating wheel, as described in an embodiment of the present invention. This method is applied to a vehicle transmission control unit and includes steps S101-S105.

[0040] S101. Monitor the vehicle's driving status to obtain vehicle information, including the vehicle's CAN bus signal and sensor signals.

[0041] In this embodiment, the vehicle CAN bus signals include vehicle speed, front wheel speed, rear wheel speed, and steering wheel angle, while the sensor signals include longitudinal acceleration and lateral acceleration of the vehicle body. When the vehicle is powered on, the transmission control software acquires vehicle speed signals, front wheel speed signals, rear wheel speed signals, vehicle attitude signals, and steering wheel angle signals in real time, and monitors and calculates the acquired signals in real time to monitor the vehicle's driving attitude.

[0042] S102. Confirm the vehicle driving condition based on the vehicle CAN bus signal. The vehicle driving condition includes four-wheel driving condition and non-four-wheel driving condition. Confirm the vehicle turning mode based on the vehicle driving condition and combined with the vehicle information. The vehicle turning mode includes four-wheel drive turning mode and two-wheel drive turning mode. Activate slope calculation and correction based on the vehicle turning mode.

[0043] Specifically, the system determines whether the vehicle is in a four-wheel driving condition based on the vehicle's CAN bus signal. If it is in a four-wheel driving condition, the system determines whether the vehicle is in four-wheel drive hub mode based on the vehicle information. If it is in four-wheel drive hub mode, the system activates slope calculation and correction. If the vehicle is not in a four-wheel driving condition, the system determines whether the vehicle is in two-wheel drive hub mode based on the vehicle information. If it is in two-wheel drive hub mode, the system activates slope calculation and correction.

[0044] In this embodiment, the slope calculation correction includes correcting the slope to 0 and disabling slip control, slope shift line correction, and fault diagnosis of turning off wheel speed signals to ensure that the vehicle is consistent with the driving state of a normal straight road.

[0045] Specifically, the criteria for determining the four-wheel drive hub mode are as follows:

[0046]

[0047] Wherein, acceleration difference = actual vehicle acceleration - longitudinal acceleration of the vehicle body, that is: acceleration difference = |actual longitudinal acceleration value of the vehicle - longitudinal acceleration value of the sensor|, actual vehicle acceleration = dv / dt, where v is velocity and t is time.

[0048] As a specific example, the first preset wheel speed difference threshold is 3 rpm, the first preset vehicle speed threshold is 6 kph, and the first acceleration threshold is 0.25 m / s². 2 The second acceleration threshold is 0.5 m / s². 2 The first acceleration difference threshold is 0.9 m / s². 2 The first turning angle threshold is 20°.

[0049] In this embodiment, the conditions for determining the four-wheel drive hub mode are: the difference between the front wheel speed and the rear wheel speed is less than 3 rpm, the vehicle speed is greater than 6 kph, and the longitudinal acceleration of the vehicle body is less than 0.25 m / s². 2 Furthermore, the lateral acceleration of the vehicle body is less than 0.5 m / s². 2 And the acceleration difference is greater than 0.9 m / s². 2 And the steering wheel angle is less than 20°.

[0050] Furthermore, the criteria for determining the two-wheel drive hub mode are as follows:

[0051]

[0052] In this embodiment, the first preset wheel speed threshold is 10 rpm; the second preset wheel speed threshold is 3 rpm; and the first acceleration threshold is 0.25 m / s². 2 The second acceleration threshold is 0.5 m / s². 2 The first turning angle threshold is 20°.

[0053] In this embodiment, the condition for determining the two-wheel drive hub mode is:

[0054] If the vehicle's front wheel speed is greater than 10 rpm, the rear wheel speed is less than 3 rpm, and the vehicle's longitudinal acceleration is less than 0.25 m / s², then... 2 Furthermore, the lateral acceleration of the vehicle body is less than 0.5 m / s². 2 And the steering wheel angle is less than 20°.

[0055] When any of the above-mentioned judgment conditions are met, the technical solution in this application will identify that the current vehicle is in a special driving state on a rotating wheel. The slope calculation and correction function described in this solution will be activated, and the wheel slippage suppression function and the shift line slope correction function will be deactivated. Furthermore, the actual slope of the road conditions will be accurately calculated to assist the engine in correctly correcting the accelerator pedal map and controlling the activation and deactivation of the intelligent start-stop function. The specific solution is as follows:

[0056] Once this patented solution detects that one of the above-mentioned judgment conditions is set, the "slope calculation and correction" function will be activated. Internally, the system will disable the slope calculation function and the slope-based shift line correction to ensure that the vehicle's driving state is no different from driving on a flat road. At the same time, the system will continuously detect the current vehicle driving posture to determine whether the current vehicle driving posture meets the exit or entry conditions.

[0057] S103. Determine whether the corrected vehicle information meets the preset conditions based on the vehicle's driving conditions.

[0058] When the vehicle is operating under four-wheel driving conditions, the preset conditions are:

[0059] |Front wheel speed - Rear wheel speed| > Second preset wheel speed difference threshold, or vehicle longitudinal acceleration > First acceleration threshold, or vehicle lateral acceleration > Second acceleration threshold, and or steering wheel angle > First steering angle threshold.

[0060] As a specific example, the second preset wheel speed difference threshold is 10 rpm; the first acceleration threshold is 0.25 m / s². 2 The second acceleration threshold is 0.5 m / s². 2 The first turning angle threshold is 20°.

[0061] In this embodiment, the preset conditions for four-wheel driving are: |front wheel speed - rear wheel speed| > 10 rpm, or the longitudinal acceleration of the vehicle body > 0.25 m / s². 2 Or the lateral acceleration of the vehicle body is greater than 0.5 m / s². 2 And, or the steering wheel angle is greater than 20°. When the vehicle is not in a four-wheel driving condition, the preset condition is:

[0062] The front wheel speed is greater than the first preset wheel speed threshold, and the rear wheel speed is greater than the first preset wheel speed threshold, or the longitudinal acceleration of the vehicle body is greater than the first acceleration threshold, or the lateral acceleration of the vehicle body is greater than the second acceleration threshold, or the steering wheel angle is greater than the first steering angle threshold.

[0063] As a specific example, the first preset wheel speed threshold is 10 rpm; the first acceleration threshold is 0.25 m / s². 2 The second acceleration threshold is 0.5 m / s². 2 The first turning angle threshold is 20°.

[0064] In this embodiment, the preset conditions for non-four-wheel driving are: front wheel speed > 10 rpm and rear wheel speed > 10 rpm, or vehicle longitudinal acceleration > 0.25 m / s². 2 Or the lateral acceleration of the vehicle body is greater than 0.5 m / s². 2 Or the steering wheel angle is greater than 20°.

[0065] Specifically:

[0066]

[0067] In the formula: V FAVG V represents the average speed of the left front wheel and the right front wheel; FAVG >Preset threshold for average front wheel speed; V RAVG V represents the average speed of the left rear wheel and the right rear wheel; RAVG > Rear wheel average speed preset threshold; V FL Indicates the speed of the left front wheel; V FR Indicates the speed of the right front wheel; V RL Indicates the speed of the left rear wheel; VRR Indicates the speed of the right rear wheel;

[0068] Furthermore, the wheel speed difference between the front and rear wheels of the vehicle is:

[0069] △V=|V FAVG -V RAVG | <Preset wheel speed difference threshold;

[0070] In the formula, △V represents the wheel speed difference between the front and rear wheels;

[0071] Furthermore, the method for calculating the actual acceleration value of the vehicle is as follows:

[0072] △α=|α sens -α Actual |;

[0073]

[0074] In the formula: △α represents the difference between the actual acceleration of the vehicle and the longitudinal acceleration of the vehicle body, in m / s². 2 ;α sens This represents the longitudinal acceleration of the vehicle body obtained through vehicle body sensors; α Actual θ represents the actual acceleration of the vehicle calculated from its speed; θ represents the slope value approximated by trigonometric functions.

[0075] If the corrected vehicle information meets the preset conditions, then proceed to step S104.

[0076] If the corrected vehicle information does not meet the preset conditions, then proceed to step S105.

[0077] S104. Exit the current vehicle swivel mode and enter normal control, and return to step S102 to repeatedly determine whether the vehicle information meets the preset conditions of the swivel mode.

[0078] S105. Continue executing the current vehicle swivel mode.

[0079] In this embodiment, the "slope correction" function includes three parts: application conditions, function implementation steps, and function exit. When the function is activated, this solution can shield the influence of slope on shift point correction. Furthermore, through actual driving tests under various road conditions, including hill starts, flat road starts, icy / snowy road starts, and constant speed driving on flat roads, the slope correction of this patented solution does not conflict with the slope calculation of real road surfaces and has no impact on actual vehicle driving under road conditions. For details, please compare... Figure 3 and Figure 4 The test results, among which, Figure 3In real-world applications, the vehicle lacks a "slope correction" function during the wheel rotation test. The slope calculation is triggered during vehicle acceleration and deceleration, causing the shift logic to enter slope correction mode. The shift points executed by the software do not match the actual driving road conditions, affecting the test results or causing the test to fail. Figure 4 In practical applications of this invention, when the vehicle is tested in a wheel-turning test, the "slope correction" function is activated. During the vehicle's acceleration and deceleration, the slope signal remains at 0, and the shift lines executed by the software match the actual driving conditions, thus not affecting the test results.

[0080] In summary, the slope calculation and correction method based on vehicle driving in a rotating wheel, as described in the above embodiments of the present invention, identifies whether the vehicle is in a special state of driving in a rotating wheel by monitoring the vehicle's overall information, thereby correcting the slope calculation logic and the fault reporting logic of the transmission controller. Specifically, the technical solution of this application is integrated into the transmission control unit, which determines the driving conditions of the vehicle by acquiring signals such as actual vehicle speed, front wheel speed, rear wheel speed, vehicle posture, and steering wheel angle, correctly handles slope calculation and front and rear wheel slippage, and ensures that the vehicle's operating strategy is no different from that of actual flat road driving.

[0081] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "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.

[0082] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A method for calculating and correcting the slope of a vehicle while it is traveling on a turntable, characterized in that, The calibration method, applied to a vehicle transmission control unit, includes: The vehicle's driving status is monitored to obtain vehicle information, which includes vehicle CAN bus signals and sensor signals. The vehicle CAN bus signals include vehicle speed, front wheel speed, rear wheel speed, and steering wheel angle. The sensor signals include vehicle longitudinal acceleration and vehicle lateral acceleration. The vehicle's driving condition is confirmed based on the vehicle's CAN bus signal. This includes four-wheel driving and non-four-wheel driving conditions. Based on the driving condition and vehicle information, the vehicle's turning mode is determined, including four-wheel drive and two-wheel drive modes. The slope calculation correction is then activated based on the turning mode. This step specifically includes: determining whether the vehicle is in four-wheel driving mode based on the vehicle's CAN bus signal; if in four-wheel driving mode, determining whether the vehicle is in four-wheel drive turning mode based on vehicle information; if in four-wheel drive turning mode, activating slope calculation correction; if in non-four-wheel driving mode, determining whether the vehicle is in two-wheel drive turning mode based on vehicle information; if in two-wheel drive turning mode, activating slope calculation correction. Slope calculation correction includes correcting the slope to 0 and disabling slip control, hill shift line correction, and wheel speed signal fault diagnosis to ensure the vehicle's driving condition is consistent with normal straight road driving. Based on the vehicle's driving conditions, determine whether the corrected vehicle information meets the preset conditions. If the corrected vehicle information meets the preset conditions, the current vehicle swivel mode will be exited and normal control will be entered. The process will then return to the step of confirming the vehicle's driving condition based on the vehicle's CAN bus signal. If the corrected vehicle information does not meet the preset conditions, the current vehicle swivel mode will continue to be executed. In the step of determining whether a vehicle is in four-wheel drive hub mode based on vehicle information, the criteria for determining four-wheel drive hub mode include: ； Wherein, acceleration difference = actual vehicle acceleration - longitudinal acceleration of the vehicle body, actual vehicle acceleration = dv / dt, where v is velocity and t is time; In the step of determining whether a vehicle is in two-wheel drive mode based on vehicle information, the criteria for determining two-wheel drive mode include: 。 2. The slope calculation and correction method based on vehicle driving on a turntable as described in claim 1, characterized in that, In the step of determining whether the corrected vehicle information meets preset conditions based on the vehicle's driving conditions; if the corrected vehicle information meets the preset conditions, then exiting the current vehicle steering mode and entering normal control, the preset conditions are as follows when the vehicle is in four-wheel driving mode: |Front wheel speed - Rear wheel speed| > Second preset wheel speed difference threshold, or vehicle longitudinal acceleration > First acceleration threshold, or vehicle lateral acceleration > Second acceleration threshold, and or steering wheel angle > First steering angle threshold.

3. The slope calculation and correction method based on vehicle driving on a turntable as described in claim 1, characterized in that, In the step of determining whether the corrected vehicle information meets preset conditions based on the vehicle's driving conditions; if the corrected vehicle information meets the preset conditions, then exiting the current vehicle steering mode and entering normal control, the preset conditions are as follows when the vehicle's driving conditions are not four-wheel driving conditions: The front wheel speed is greater than the first preset wheel speed threshold, and the rear wheel speed is greater than the first preset wheel speed threshold, or the longitudinal acceleration of the vehicle body is greater than the first acceleration threshold, or the lateral acceleration of the vehicle body is greater than the second acceleration threshold, or the steering wheel angle is greater than the first steering angle threshold.

Images