A pure electric bus driving acceleration self-adaptive smoothing control method and system

Abstract

The application provides a kind of pure electric bus drive acceleration self-adaptive smoothing control method and system, method includes: based on the acceleration pedal opening degree variation rate identification driving style, according to driving style determine reference acceleration and driving style coefficient;Based on the product of reference acceleration, driving style coefficient and load coefficient calculation maximum allowable acceleration threshold;Based on the deviation of real-time acceleration and preset acceleration threshold, dynamically generate torque limit value;With the minimum value of basic demand torque and torque limit value, get the demand torque after smoothing processing and output to motor controller.The application combines driving style, dynamically calculates the maximum acceleration threshold allowed under current working condition, limits vehicle demand acceleration based on the value, and then adjusts torque output to realize the smooth adjustment of drive acceleration, solves the problem of excessive longitudinal impact and poor ride comfort caused by sudden change of motor torque during acceleration process of traditional pure electric bus.

Description

Technical Field

[0001] This invention relates to the field of automatic control technology, and in particular to an adaptive smooth control method and system for the acceleration of a pure electric bus. Background Technology

[0002] The acceleration of a pure electric bus refers to the process by which the vehicle relies on the power output of the drive motor to transition the vehicle body from a standstill or low speed to a high speed. Its core lies in achieving a smooth power transmission by reasonably controlling the motor torque.

[0003] In real-world driving scenarios, the driver's intention to operate the accelerator pedal needs to be translated into motor torque output to accelerate the vehicle. However, traditional pure electric buses use a control method that directly outputs torque based on the accelerator pedal opening and the current motor speed, a method that has gradually revealed significant shortcomings in practical applications.

[0004] Specifically, on the one hand, different drivers have different driving styles. Some aggressive drivers will rapidly depress the accelerator pedal to obtain greater power, which directly causes a sudden change in motor torque, resulting in longitudinal impact on the vehicle and severely affecting ride comfort. On the other hand, when the vehicle is unloaded and fully loaded, the same accelerator pedal input will produce drastically different acceleration experiences. When unloaded, there is a tendency for power overshoot, while when fully loaded, there may be insufficient power response. It is evident that traditional drive control methods cannot adapt to different driving habits or cope with different load conditions, ultimately causing problems with both power response and acceleration linearity. Summary of the Invention

[0005] To address the aforementioned issues, this invention proposes an adaptive smooth control method and system for the driving acceleration of pure electric buses. By collecting parameters such as vehicle load, speed, and battery SOC in real time, and combining them with driving style, the maximum allowable acceleration threshold under the current operating conditions is dynamically calculated. Based on this value, the required acceleration of the vehicle is limited, and then the driving acceleration is smoothly adjusted by adjusting the torque output. This solves the problems of excessive longitudinal impact and poor ride comfort caused by sudden changes in motor torque during the acceleration process of traditional pure electric buses.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides an adaptive smooth control method for the acceleration of a pure electric bus, comprising: Real-time acquisition of vehicle status parameters, including vehicle speed, accelerator pedal opening, load, and battery SOC; calculation of real-time acceleration based on current vehicle speed; Driving style is identified based on the rate of change of accelerator pedal opening, and a baseline acceleration and driving style coefficient are determined based on the driving style. The maximum permissible acceleration threshold is dynamically calculated based on the product of the baseline acceleration, driving style coefficient, and load coefficient. Based on the deviation between the real-time acceleration and the preset acceleration threshold, a torque limit value is dynamically generated; the minimum value between the basic required torque and the torque limit value is taken to obtain the smoothed required torque, which is then output to the motor controller; the preset acceleration threshold includes a minimum and a maximum allowable acceleration threshold.

[0007] Preferably, the vehicle speed is calculated based on the average value of the motor speed signal and the front axle speed signal; The accelerator pedal opening is calculated based on the battery SOC and the current actual load.

[0008] Preferably, the method of identifying driving style based on the rate of change of accelerator pedal opening specifically includes: When the rate of change of the accelerator pedal opening does not exceed the first percentage within a preset time, it is determined to be a conservative driving style; When the rate of change of the accelerator pedal opening exceeds the first percentage but does not exceed the second percentage within a preset time, it is determined to be a normal driving style. When the rate of change of the accelerator pedal opening exceeds the second percentage within a preset time, it is determined to be an aggressive driving style; The first percentage is less than the second percentage.

[0009] Preferably, determining the reference acceleration and driving style coefficient based on driving style specifically includes: A table showing the correspondence between preset driving styles and baseline acceleration and driving style coefficients; wherein, the baseline acceleration and driving style coefficients for conservative driving style, normal driving style, and aggressive driving style increase sequentially.

[0010] Preferably, the load factor is calculated based on the ratio of the load to the reference load.

[0011] Preferably, the step of dynamically generating a torque limit value based on the deviation between the real-time acceleration and a preset acceleration threshold specifically includes: If the real-time acceleration is less than the minimum allowable acceleration, the basic required torque is obtained by looking up a table based on the current accelerator pedal opening and motor speed, and used as the first torque limit value. ; If the real-time acceleration exceeds the maximum permissible acceleration, the second torque limit value is set to... ; This represents the peak torque at the current motor speed. If real-time acceleration Minimum allowable acceleration and maximum permissible acceleration Between, the third torque limit value is set to .

[0012] Preferably, the step of taking the minimum value between the basic required torque and the torque limit value to obtain the smoothed required torque and outputting it to the motor controller specifically includes: If the real-time acceleration is less than the minimum allowable acceleration, the first torque limit value will be transmitted to the motor controller as the required torque. If the real-time acceleration is greater than the maximum allowable acceleration, the minimum value of the basic required torque and the second torque limit value is taken as the required torque and transmitted to the motor controller. If the real-time acceleration is between the minimum allowable acceleration and the maximum allowable acceleration, the minimum value between the basic required torque and the third torque limit value is taken and transmitted to the motor controller as the required torque.

[0013] Secondly, the present invention provides an adaptive smooth control system for the drive acceleration of a pure electric bus, comprising: The parameter acquisition module is configured to acquire vehicle status parameters in real time, including vehicle speed, accelerator pedal opening, load and battery SOC; and calculate real-time acceleration based on the current vehicle speed. The style introduction module is configured to identify driving style based on the rate of change of accelerator pedal opening, and determine the baseline acceleration and driving style coefficient according to the driving style. The acceleration threshold calculation module is configured to dynamically calculate the maximum permissible acceleration threshold based on the product of the baseline acceleration, driving style coefficient, and load coefficient. The torque generation and determination module is configured to dynamically generate a torque limit value based on the deviation between the real-time acceleration and the preset acceleration threshold; take the minimum value between the basic required torque and the torque limit value to obtain the smoothed required torque and output it to the motor controller; the preset acceleration threshold includes a minimum and a maximum allowable acceleration threshold.

[0014] Thirdly, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the adaptive smooth control method for driving acceleration of a pure electric bus as described in the first aspect.

[0015] Fourthly, the present invention provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of the adaptive smooth control method for driving acceleration of a pure electric bus as described in the first aspect.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention acquires multi-dimensional vehicle state parameters in real time, accurately calculates real-time acceleration, identifies driving style by combining the accelerator pedal opening change rate, and dynamically determines the maximum permissible acceleration threshold by integrating the baseline acceleration, driving style coefficient, and load coefficient. Finally, it generates a torque limit value based on the deviation between the real-time acceleration and the preset acceleration threshold, smoothing the basic torque requirement. This approach adapts to different driver styles and handles varying vehicle loads, effectively avoiding longitudinal impacts caused by sudden changes in motor torque. It significantly improves ride comfort during acceleration in pure electric buses, making power output more linear and smooth, and providing passengers with a superior driving experience.

[0017] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0018] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute a limitation thereof.

[0019] Figure 1 The main flowchart of an adaptive smooth control method for driving acceleration of a pure electric bus provided in an embodiment of the present invention is shown. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] Example 1 like Figure 1 As shown in the figure, this embodiment discloses an adaptive smooth control method for the acceleration of a pure electric bus, including the following steps: S1: Real-time acquisition of vehicle status parameters, including vehicle speed, accelerator pedal opening, load, and battery SOC; calculation of real-time acceleration based on current vehicle speed; S2: Identify driving style based on the rate of change of accelerator pedal opening, and determine the baseline acceleration and driving style coefficient according to the driving style; S3: Dynamically calculate the maximum permissible acceleration threshold based on the product of the baseline acceleration, driving style coefficient, and load coefficient; S4: Based on the deviation between the real-time acceleration and the preset acceleration threshold, a torque limit value is dynamically generated; the minimum value between the basic required torque and the torque limit value is taken to obtain the smoothed required torque and output to the motor controller; the preset acceleration threshold includes the minimum and maximum allowable acceleration thresholds.

[0022] Next, combined Figure 1This embodiment provides a detailed description of an adaptive smooth control method for the acceleration of a pure electric bus.

[0023] In S1, firstly, the vehicle controller obtains vehicle status parameters through the CAN network, including vehicle speed, accelerator pedal opening, load, and battery SOC.

[0024] The process involves acquiring the motor speed signal, converting it into a first vehicle speed signal, and then comparing it with the front axle speed signal. The average of the two signals is taken to obtain the final vehicle speed. The first vehicle speed signal is represented as follows: ; In the formula, V is the vehicle speed, Re is the tire rolling radius, n is the motor speed, and τ is the rear axle speed ratio.

[0025] In this embodiment, by converting the motor speed signal into a vehicle speed signal, vehicle speed data can be obtained from the power output terminal based on the correlation between the motor and the vehicle transmission. This signal is then combined with the front axle speed signal, and the average of the two is used to determine the final vehicle speed. On the one hand, the two signals can be used for mutual verification, reducing the errors that may be caused by the acquisition or conversion of a single signal and improving the accuracy of the vehicle speed data. On the other hand, combining vehicle speed-related signals from different sources can more comprehensively and accurately reflect the actual driving speed of the vehicle, providing a reliable basis for subsequent vehicle speed-based vehicle control and ensuring the effectiveness and stability of the control strategy.

[0026] The system receives battery SOC information and current actual load information, and converts analog voltage values ​​into accelerator pedal opening signals. It should be understood that the process of converting these signals into accelerator pedal opening signals is achievable by those skilled in the art.

[0027] Furthermore, the required acceleration is calculated in real time based on the current vehicle speed signal. The vehicle speed signal is collected every 10ms, and the real-time acceleration is calculated every 50ms. .

[0028] In S2, conventional technologies typically use a preset fixed value or rely solely on a single parameter (such as vehicle speed) to determine the maximum permissible acceleration threshold, without fully considering the impact of driving style and vehicle load. However, different drivers have significantly different driving styles. Aggressive drivers are prone to sudden torque changes in the motor due to rapid acceleration, while conservative drivers prefer a smooth ride. Furthermore, the same accelerator pedal input will produce drastically different acceleration experiences when the vehicle is empty versus fully loaded. This method, relying solely on a fixed value or a single parameter, cannot adapt to diverse driving habits and load conditions, resulting in either insufficient power response or a lack of linearity in acceleration, affecting ride comfort. To alleviate this problem, this embodiment proposes to comprehensively consider driving style and load information to calculate the maximum permissible acceleration threshold.

[0029] First, the real-time driving style is identified based on the rate of change of accelerator pedal opening. When the rate of change of accelerator pedal opening does not exceed the first percentage within a preset time, it is determined to be a conservative driving style. When the rate of change of the accelerator pedal opening exceeds the first percentage but does not exceed the second percentage within a preset time, it is determined to be a normal driving style. When the rate of change of the accelerator pedal opening exceeds the second percentage within a preset time, it is determined to be an aggressive driving style; The first percentage is less than the second percentage.

[0030] As one implementation method, the preset time is 40ms, the first percentage is 15%, and the second percentage is 30%.

[0031] Since the speed at which a driver depresses the accelerator pedal (i.e., the rate of change in pedal opening) directly reflects their driving style, aggressive drivers will press the pedal quickly and deeply, resulting in a large rate of change in pedal opening; while conservative drivers will press it slowly and lightly, resulting in a small rate of change in pedal opening. This embodiment determines the driving style based on this rate of change, accurately capturing the driver's intentions and adapting to different baseline acceleration and coefficients. This ensures that vehicle acceleration matches driving habits while avoiding sudden torque changes in the later stages, improving ride comfort and the smoothness of power output.

[0032] Furthermore, according to a preset relationship table, the baseline acceleration and driving style coefficient are determined based on the driving style. This preset relationship table shows the correspondence between driving style and baseline acceleration / driving style coefficient, where the baseline acceleration and driving style coefficient increase sequentially for conservative, normal, and aggressive driving styles. One implementation method is shown in Table 1.

[0033] Table 1. Preset Relationship Table;

[0034] In S3, the maximum permissible acceleration threshold is dynamically calculated based on the product of the baseline acceleration, driving style coefficient, and load coefficient. : ; ; Where m is the load factor. This represents the current actual load (tons). Standard load capacity (tons).

[0035] Furthermore, The upper limit is set to 1.5. The lower limit is set at 0.5. Furthermore, when the battery SOC is below 15%, Take a fixed value of 0.5 .

[0036] In this embodiment, the maximum permissible acceleration threshold is calculated by multiplying the baseline acceleration, driving style coefficient, and load coefficient. This comprehensively adapts to driving habits and vehicle load, providing ample power for aggressive driving, smoother driving for conservative driving, and a more reasonable acceleration experience under different loads. Clearly defining the upper and lower limits of the maximum permissible acceleration threshold prevents excessive acceleration from causing shocks or insufficient acceleration from causing power shortages, ensuring that the acceleration process remains within a reasonable range. When the battery SOC is below 15%, a fixed acceleration value is used to avoid over-discharge damaging the battery at low charge levels, while ensuring basic power output. This achieves multi-dimensional optimization of driving experience, driving smoothness, and battery life.

[0037] In S4, while determining the maximum permissible acceleration, a minimum permissible acceleration threshold is set; for example, it is set to 0.5. The maximum and minimum allowable acceleration thresholds are used as the upper and lower limits of the preset acceleration threshold.

[0038] Based on real-time acceleration The deviation from the preset acceleration threshold determines the torque adjustment stage. Torque limit values ​​are dynamically generated at different stages, and the minimum value between the base required torque and the torque limit value is selected as the required torque and output to the motor controller. This achieves smooth processing of the motor's output torque, improving ride comfort. (1) When real-time acceleration At this time, no action is taken; the vehicle controller looks up the basic torque requirement from a table based on the current accelerator pedal opening and motor speed. This serves as the first torque limit value for the motor controller.

[0039] (2) When real-time acceleration At that time, the required torque = min{ , }, second torque limit value , This represents the peak torque at the current motor speed. The base torque requirement is used, while the peak torque is obtained by looking up a table using the motor's external characteristics.

[0040] (3) When real-time acceleration At that time, the required torque min{ , The third torque limit value is set as follows: ; Among them, the third torque limit value Based on real-time acceleration The relationship between the maximum and minimum allowable acceleration thresholds affects the peak torque of the motor. Perform dynamic scaling. When exist arrive When changing within an interval, It will adjust linearly accordingly, allowing the torque output to transition smoothly with acceleration, avoiding sudden changes in torque, thus achieving smooth torque control and making the vehicle acceleration process more linear and smooth.

[0041] This embodiment divides the driving process into stages by comparing real-time acceleration with an acceleration threshold calculated based on driving style and load. For each stage, the required torque is determined by taking the minimum value between different torque limits and the basic required torque. This method accurately matches different driving scenarios and vehicle states. When the acceleration is below the minimum threshold, the basic required torque is used directly to ensure power response; when it is above the maximum threshold, the torque is limited to avoid impact; and when it is in the intermediate range, the torque is dynamically adjusted to achieve a smooth transition. This not only matches the driver's intentions but also allows for a more linear and stable motor torque output based on real-time conditions such as vehicle load, effectively solving the problem of sudden torque changes in traditional control and significantly improving the ride comfort and driving smoothness of pure electric buses during acceleration.

[0042] This specific embodiment achieves adaptive smooth control through multi-dimensional collaboration. First, considering factors such as driving style and vehicle load, the maximum permissible acceleration threshold is dynamically calculated, while a minimum permissible acceleration threshold is set to construct a reasonable acceleration range. Then, based on the relationship between real-time acceleration and this range, different stages are defined, and a targeted torque determination strategy is adopted in each stage: when the real-time acceleration is below the minimum threshold, the basic required torque is directly output to ensure power response; when it is above the maximum threshold, the minimum value between the basic required torque and the dynamically limited torque is taken to forcibly limit the peak torque; when it is within the range, the smooth output torque is calculated based on the deviation between the real-time acceleration and the threshold, and then the minimum value is taken between the real-time acceleration and the basic required torque. This staged approach, based on acceleration and dynamically adjusting torque, allows the motor torque output to change linearly with real-time operating conditions, avoiding sudden torque changes, thereby achieving a smooth transition in the driving acceleration process and effectively improving ride comfort.

[0043] Example 2 This embodiment provides an adaptive smooth control system for the acceleration of a pure electric bus, including: The parameter acquisition module is configured to acquire vehicle status parameters in real time, including vehicle speed, accelerator pedal opening, load and battery SOC; and calculate real-time acceleration based on the current vehicle speed. The style introduction module is configured to identify driving style based on the rate of change of accelerator pedal opening, and determine the baseline acceleration and driving style coefficient according to the driving style. The acceleration threshold calculation module is configured to dynamically calculate the maximum permissible acceleration threshold based on the product of the baseline acceleration, driving style coefficient, and load coefficient. The torque generation and determination module is configured to dynamically generate a torque limit value based on the deviation between the real-time acceleration and the preset acceleration threshold; take the minimum value between the basic required torque and the torque limit value to obtain the smoothed required torque and output it to the motor controller; the preset acceleration threshold includes a minimum and a maximum allowable acceleration threshold.

[0044] Example 3 This embodiment provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the adaptive smooth control method for driving acceleration of a pure electric bus as described in Embodiment 1 above.

[0045] Example 4 This embodiment provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the steps in the adaptive smooth control method for driving acceleration of a pure electric bus as described in Embodiment 1 above.

[0046] The steps or modules involved in Embodiments 2 to 4 above correspond to those in Embodiment 1. For specific implementation details, please refer to the relevant description section of Embodiment 1. The term "computer-readable storage medium" should be understood as a single medium or multiple media including one or more instruction sets; it should also be understood as including any medium capable of storing, encoding, or carrying an instruction set for execution by a processor and enabling the processor to perform any of the methods in this invention.

[0047] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for adaptive smooth control of acceleration in pure electric buses, characterized in that, include: Real-time acquisition of vehicle status parameters, including vehicle speed, accelerator pedal opening, load, and battery SOC; Real-time acceleration is calculated based on the current vehicle speed; vehicle speed is calculated based on the average of the motor speed signal and the front axle speed signal; accelerator pedal opening is calculated based on battery SOC and current actual load. Driving style is identified based on the rate of change of accelerator pedal opening, and a baseline acceleration and driving style coefficient are determined based on the driving style. The maximum permissible acceleration threshold is dynamically calculated based on the product of the baseline acceleration, driving style coefficient, and load coefficient. Based on the deviation between the real-time acceleration and the preset acceleration threshold, a torque limit value is dynamically generated; specifically, if the real-time acceleration is less than the minimum allowable acceleration, the basic required torque is obtained by looking up a table based on the current accelerator pedal opening and motor speed, and used as the first torque limit value. If the real-time acceleration exceeds the maximum permissible acceleration, the second torque limit value is set to... ; This represents the peak torque at the current motor speed; if real-time acceleration... Minimum allowable acceleration and maximum permissible acceleration Between, the third torque limit value is set to The minimum value between the basic required torque and the torque limit value is taken to obtain the smoothed required torque, which is then output to the motor controller; the preset acceleration threshold includes the minimum and maximum allowable acceleration thresholds.

2. The adaptive smooth control method for acceleration of a pure electric bus as described in claim 1, characterized in that, The method of identifying driving style based on the rate of change of accelerator pedal opening is as follows: When the rate of change of the accelerator pedal opening does not exceed the first percentage within a preset time, it is determined to be a conservative driving style; When the rate of change of the accelerator pedal opening exceeds the first percentage but does not exceed the second percentage within a preset time, it is determined to be a normal driving style. When the rate of change of the accelerator pedal opening exceeds the second percentage within a preset time, it is determined to be an aggressive driving style; The first percentage is less than the second percentage.

3. The adaptive smooth control method for acceleration of a pure electric bus as described in claim 1, characterized in that, The determination of the baseline acceleration and driving style coefficient based on driving style specifically includes: A table showing the correspondence between preset driving styles and baseline acceleration and driving style coefficients; wherein, the baseline acceleration and driving style coefficients for conservative driving style, normal driving style, and aggressive driving style increase sequentially.

4. The adaptive smooth control method for acceleration of a pure electric bus as described in claim 1, characterized in that, The load factor is calculated based on the ratio of the load to the reference load.

5. The adaptive smooth control method for acceleration of a pure electric bus as described in claim 1, characterized in that, The step of taking the minimum value between the basic required torque and the torque limit value to obtain the smoothed required torque and outputting it to the motor controller specifically includes: If the real-time acceleration is less than the minimum allowable acceleration, the first torque limit value will be transmitted to the motor controller as the required torque. If the real-time acceleration is greater than the maximum allowable acceleration, the minimum value of the basic required torque and the second torque limit value is taken as the required torque and transmitted to the motor controller. If the real-time acceleration is between the minimum allowable acceleration and the maximum allowable acceleration, the minimum value between the basic required torque and the third torque limit value is taken and transmitted to the motor controller as the required torque.

6. A pure electric bus drive acceleration adaptive smooth control system, characterized in that, include: The parameter acquisition module is configured to acquire vehicle status parameters in real time, including vehicle speed, accelerator pedal opening, load and battery SOC; Real-time acceleration is calculated based on the current vehicle speed; vehicle speed is calculated based on the average of the motor speed signal and the front axle speed signal; accelerator pedal opening is calculated based on battery SOC and current actual load. The style introduction module is configured to identify driving style based on the rate of change of accelerator pedal opening, and determine the baseline acceleration and driving style coefficient according to the driving style. The acceleration threshold calculation module is configured to dynamically calculate the maximum permissible acceleration threshold based on the product of the baseline acceleration, driving style coefficient, and load coefficient. The torque generation and determination module is configured to dynamically generate a torque limit value based on the deviation between the real-time acceleration and a preset acceleration threshold; specifically, this includes: if the real-time acceleration is less than the minimum allowable acceleration, obtaining the basic required torque from a table based on the current accelerator pedal opening and motor speed, and using this as the first torque limit value. If the real-time acceleration exceeds the maximum permissible acceleration, the second torque limit value is set to... ; This represents the peak torque at the current motor speed; if real-time acceleration... Minimum allowable acceleration and maximum permissible acceleration Between, the third torque limit value is set to The minimum value between the basic required torque and the torque limit value is taken to obtain the smoothed required torque, which is then output to the motor controller; the preset acceleration threshold includes the minimum and maximum allowable acceleration thresholds.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the steps in the adaptive smooth control method for driving acceleration of a pure electric bus as described in any one of claims 1-5.

8. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps in the adaptive smooth control method for driving acceleration of a pure electric bus as described in any one of claims 1-5.

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