Optimization method for acceleration expectation of hybrid vehicle

Abstract

The invention belongs to the technical field of acceleration detection and judgment of hybrid vehicles, and particularly relates to a method for optimizing acceleration expectation of a hybrid vehicle, and the method comprises the following specific steps: S1, monitoring the working state parameters of an engine and a power battery in real time; s2, performing power derating judgment based on the working state parameters of the engine and the power battery; s3, generating a corresponding derating coefficient; and S4, the torque requested by the driver through the accelerator pedal is corrected in the whole vehicle control software, so that the driver perceives that the vehicle power is reduced in advance, and meanwhile, a control instruction is sent to a power source. According to a correction calculation formula: corrected request torque = original request torque * final derating coefficient; and calculating the corrected request torque. Power derating judgment of an engine and a power battery is conducted, a derating coefficient is generated, torque requested by a driver is corrected through vehicle control software, the driver is made to perceive vehicle power reduction in advance, and acceleration expectation is optimized.

Description

Technical Field

[0001] The present invention relates to the technical field of hybrid vehicle acceleration detection and judgment, and in particular to a method for optimizing hybrid vehicle acceleration expectations. Background Art

[0002] A hybrid vehicle is a vehicle whose drive system is composed of two or more single drive systems that can operate simultaneously. The vehicle's driving power is provided by the single drive systems individually or jointly according to the actual driving state of the vehicle.

[0003] Hybrid vehicles are generally referred to as hybrid electric vehicles, which use traditional internal combustion engines (diesel engines or gasoline engines) and electric motors as power sources. Some engines have been modified to use other alternative fuels, such as compressed natural gas, propane and ethanol fuel.

[0004] The engine and battery of a hybrid vehicle can experience power derating under extreme operating conditions. Because drivers lack the ability to proactively perceive reduced vehicle power, they can easily misjudge their acceleration expectations, leading to dangerous situations. For example, a full-throttle overtaking attempt can lead to a failed attempt due to insufficient power. Therefore, a strategy is needed to proactively inform drivers of changes in vehicle power and optimize acceleration expectations. Summary of the Invention

[0005] The object of the present invention is to provide a method for optimizing the acceleration expectation of a hybrid vehicle to solve the problems raised in the above background technology.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for optimizing the acceleration expectation of a hybrid vehicle. The specific steps of the method for optimizing the acceleration expectation of a hybrid vehicle are as follows: S1: Real-time monitoring of the working status parameters of the engine and power battery; An intake pressure sensor and an intake temperature sensor are set and integrated in the engine intake pipe. The intake pressure sensor monitors the engine intake pressure in real time, and the intake temperature sensor monitors the engine intake temperature. The engine intake pressure and engine intake temperature provide a basis for determining engine derating. Set up a battery capacity sensor and a battery cell temperature sensor. The battery capacity sensor and the battery cell temperature sensor are set at the power battery and are electrically connected to the power battery. The battery capacity sensor measures the power battery state of charge, and the battery cell temperature sensor monitors the power battery cell temperature in real time. The power state of charge and the battery cell temperature are key parameters for determining power battery derating. S2: Perform power derating determination based on the operating status parameters of the engine and power battery; An accelerator pedal position sensor and a vehicle speed sensor are also provided. The accelerator pedal position sensor obtains information on the degree of opening of the accelerator pedal by the driver to determine the driver's original requested torque. The vehicle speed sensor monitors the vehicle's speed in real time and uses this information together with the accelerator pedal opening information to determine the original requested torque. The intake pressure sensor, intake temperature sensor, battery charge sensor, cell temperature sensor, accelerator pedal position sensor, and vehicle speed sensor are connected to the vehicle control unit. The vehicle control unit, as the core control component, receives data from each sensor, processes and analyzes the data, and makes power derating judgments. S3: Generate corresponding derating factor; S4: The torque requested by the driver through the accelerator pedal is corrected in the vehicle control software so that the driver can sense the reduction in vehicle power in advance and send control instructions to the power source at the same time.

[0007] Preferably, the vehicle control unit integrates an accelerator pedal MAP module, an engine derating determination module, a power battery derating determination module, a derating coefficient calculation module and a torque correction module.

[0008] Preferably, the accelerator pedal MAP module determines the driver's original requested torque based on the collected accelerator pedal opening and vehicle speed information. The accelerator pedal MAP module has a built-in mapping table of the corresponding relationship between the accelerator pedal opening and the original requested torque. It searches for and outputs the corresponding original requested torque value through the real-time collected accelerator pedal opening and vehicle speed information.

[0009] Preferably, the engine derating determination module has a built-in two-dimensional lookup table based on engine characteristics and test data. The engine derating determination module receives intake pressure and intake temperature information, and determines the engine derating coefficient by querying the engine derating coefficient two-dimensional lookup table.

[0010] Preferably, the power battery derating determination module has a built-in two-dimensional lookup table, which is constructed based on the performance characteristics of the power battery and a large amount of test data, and accurately derives the corresponding derating coefficient based on the battery status parameters. The power battery derating determination module obtains battery power and cell temperature information, and calculates the power battery derating coefficient through the two-dimensional lookup table of the power battery derating coefficient.

[0011] Preferably, the derating coefficient calculation module multiplies the engine derating coefficient and the power battery derating coefficient, and obtains the final derating coefficient through range restriction, and the range is restricted between 0-1.

[0012] Preferably, the torque correction module: according to the final derating factor and the original requested torque, according to the correction calculation formula: Corrected requested torque = original requested torque * final derating factor; The corrected requested torque is calculated and sent to the engine and electric motor.

[0013] Compared with the prior art, the present invention has the following beneficial effects: The engine and power battery power derating is determined, a derating coefficient is generated, and the driver's requested torque is corrected in the vehicle control software, so that the driver can perceive the reduction in vehicle power in advance and optimize acceleration expectations. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Flow chart of the optimization method of the present invention. DETAILED DESCRIPTION

[0015] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0016] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0017] For example 1, please refer to Figure 1 The present invention provides a technical solution: a method for optimizing the acceleration expectation of a hybrid vehicle. The specific steps of the method for optimizing the acceleration expectation of a hybrid vehicle are as follows: The vehicle control unit integrates an accelerator pedal MAP module, an engine derating determination module, a power battery derating determination module, a derating coefficient calculation module and a torque correction module.

[0018] S1: Real-time monitoring of the working status parameters of the engine and power battery; An intake pressure sensor and an intake temperature sensor are set and integrated in the engine intake pipe. The intake pressure sensor monitors the engine intake pressure in real time, and the intake temperature sensor monitors the engine intake temperature. The engine intake pressure and engine intake temperature provide a basis for determining engine derating. The engine derating determination module has a built-in two-dimensional lookup table based on engine characteristics and test data. The engine derating determination module receives intake pressure and intake temperature information, and determines the engine derating coefficient by querying the two-dimensional lookup table of the engine derating coefficient.

[0019] Set up a battery capacity sensor and a battery cell temperature sensor. The battery capacity sensor and the battery cell temperature sensor are set at the power battery and are electrically connected to the power battery. The battery capacity sensor measures the power battery state of charge, and the battery cell temperature sensor monitors the power battery cell temperature in real time. The power state of charge and the battery cell temperature are key parameters for determining power battery derating. The power battery derating determination module has a built-in two-dimensional lookup table. The two-dimensional lookup table is constructed based on the performance characteristics of the power battery and a large amount of test data. The corresponding derating coefficient is accurately derived based on the battery status parameters. The power battery derating determination module obtains battery power and battery cell temperature information, and calculates the power battery derating coefficient through the two-dimensional lookup table of the power battery derating coefficient.

[0020] S2: Perform power derating determination based on the operating status parameters of the engine and power battery; An accelerator pedal position sensor and a vehicle speed sensor are also provided. The accelerator pedal position sensor obtains information on the degree of opening of the accelerator pedal by the driver to determine the driver's original requested torque. The vehicle speed sensor monitors the vehicle's speed in real time and uses this information together with the accelerator pedal opening information to determine the original requested torque. The accelerator pedal MAP module determines the driver's original requested torque based on the collected accelerator pedal opening and vehicle speed information. The accelerator pedal MAP module has a built-in mapping table of the corresponding relationship between accelerator pedal opening and original requested torque. It searches and outputs the corresponding original requested torque value through the real-time collected accelerator pedal opening and vehicle speed information.

[0021] The intake pressure sensor, intake temperature sensor, battery charge sensor, cell temperature sensor, accelerator pedal position sensor, and vehicle speed sensor are connected to the vehicle control unit. The vehicle control unit, as the core control component, receives data from each sensor, processes and analyzes the data, and makes power derating judgments. S3: Generate corresponding derating factor; The derating coefficient calculation module multiplies the engine derating coefficient and the power battery derating coefficient, and obtains the final derating coefficient through range restriction, which is limited to between 0 and 1.

[0022] S4: The torque requested by the driver through the accelerator pedal is corrected in the vehicle control software so that the driver can sense the reduction in vehicle power in advance and send control instructions to the power source at the same time.

[0023] Torque correction module: Based on the final derating factor and the original requested torque, the correction calculation formula is as follows: Corrected requested torque = original requested torque * final derating factor; The corrected requested torque is calculated and sent to the engine and electric motor.

[0024] In the second embodiment, the calculation model of the above optimization method is described in detail as follows: (1) The original requested torque is determined as follows: 1. Real-time data collection Real-time collection of accelerator pedal position and vehicle speed information is fundamental to the entire process. Accelerator pedal position is measured by a sensor mounted on the accelerator pedal. These sensors typically utilize potentiometer or Hall-effect sensors. Potentiometer sensors convert pedal position into an electrical signal by changing the resistance of the potentiometer as the accelerator pedal rotates. Hall-effect sensors utilize magnetic field fluctuations. When the accelerator pedal moves a magnetic component, the Hall element senses the magnetic field and outputs an electrical signal. This signal is transmitted in real time to the accelerator pedal map module, accurately reflecting the driver's degree of accelerator pedal application and enabling the module to understand the driver's desired powertrain trend. Vehicle speed information is collected through wheel speed sensors or speed sensors. These sensors are typically installed near the wheels, detecting wheel rotational speed and calculating vehicle speed based on parameters such as wheel radius. Speed ​​sensors can also be connected to the transmission output shaft to obtain speed information. The sensors transmit vehicle speed to the MAP module in the form of electrical or digital signals, enabling the module to monitor the vehicle's current speed in real time. 2. Construction of mapping relationship table The mapping table is the core of the accelerator pedal MAP module, meticulously constructed by engineers through extensive testing and data analysis. During the construction process, a variety of driving conditions were simulated, including frequent low-speed starts, acceleration, and braking in congested urban areas, stable medium-speed driving on suburban roads, and high-speed cruising and overtaking on highways. Under each operating condition, the optimal torque output for different combinations of accelerator pedal opening and vehicle speed is determined by combining multiple factors, including vehicle powertrain performance, fuel economy, and driving comfort. For example, in low-speed conditions in urban traffic, the corresponding raw torque request is set relatively softly when the accelerator pedal opening is small, to ensure smooth starts and avoid the jerkiness associated with frequent gear shifts. Conversely, in high-speed highway overtaking conditions, even at lower accelerator pedal openings, a higher torque output is required to meet the demands of rapid acceleration. These torque values, derived through repeated testing and optimization, are organized into a detailed mapping table and stored in the accelerator pedal MAP module's memory. 3. Determination of original requested torque When the accelerator pedal MAP module receives real-time data on accelerator pedal position and vehicle speed, it immediately uses these two data points as query criteria to search the mapping table. Specifically, the module matches the collected accelerator pedal position and vehicle speed data with the data in the mapping table.

[0025] Assuming the collected accelerator pedal opening is 50% and the vehicle speed is 30 km / h, the module searches the mapping table for the record that best matches this data set. Because the data in the mapping table may be discretely distributed, if the actual collected data cannot exactly match the table data, the module uses an interpolation algorithm, such as linear interpolation or polynomial interpolation, to estimate the corresponding original requested torque value (X Nm) based on adjacent data points.

[0026] (II) Calculation of engine derating factor is as follows: 1. Real-time data collection The intake pressure sensor and intake air temperature sensor are core components for data acquisition. Intake pressure sensors typically utilize either piezoresistive or capacitive principles. Piezoresistive sensors utilize the change in resistance of silicon wafers under pressure to convert intake pressure into an electrical signal. Capacitive sensors, by varying parameters such as the spacing between capacitor plates, convert pressure changes into capacitance changes, which are then converted into an electrical signal. These sensors, installed in locations such as the engine intake manifold, monitor intake pressure in real time and transmit this information as an electrical signal to the engine derating determination module. Intake air temperature sensors are often thermistor-type sensors, whose resistance changes significantly with temperature. As intake air temperature rises, the thermistor's resistance decreases; as temperature decreases, its resistance increases. The sensor converts this resistance change into an electrical signal, which is transmitted to the engine derating determination module, allowing it to monitor intake air temperature in real time. 2. Establishment of a two-dimensional lookup table for engine derating coefficients The two-dimensional lookup table for engine derating factors requires extensive testing and data analysis. Engineers simulate various extreme and conventional intake pressure and temperature combinations on the engine test bench. Intake temperature and intake pressure are key parameters that affect the engine's intake efficiency. They directly affect the quality of the combustible mixture by changing the intake volume and air density, and ultimately have a significant impact on the engine's maximum power.

[0027] Temperature rises: the volume of air expands, the density decreases, and the number of oxygen molecules per unit volume decreases, resulting in insufficient actual air intake.

[0028] Lower temperature: Air density increases, and more oxygen can be inhaled under the same volume, which is beneficial to improving combustion efficiency.

[0029] Pressure increases: The air is compressed, the density increases significantly, the number of oxygen molecules per unit volume increases, and the air intake volume increases.

[0030] Pressure reduction: air density decreases, air intake is insufficient, and engine power is limited (such as in plateau areas).

[0031] Through extensive testing and data collection under various operating conditions, intake pressure, intake temperature, and the corresponding engine derating factors were organized into a two-dimensional table. In this two-dimensional table, intake pressure is one dimension and intake temperature is another. Each intersection corresponds to a specific engine derating factor, thus establishing a corresponding relationship between intake pressure, intake temperature, and engine derating factors.

[0032] For example, when the intake pressure is Y kPa and the intake temperature is Z degrees Celsius, the engine derating factor obtained by looking up the table is A.

[0033] (III) Calculation of power battery derating factor is as follows: The power battery derating determination module obtains data from the battery state of charge (SOC) sensor and the battery cell temperature sensor, and determines the derating coefficient using a two-dimensional lookup table of the power battery derating coefficient.

[0034] 1. Real-time data collection (1) Battery SOC data collection Battery SOC sensors primarily utilize the ampere-hour integration method, the open-circuit voltage method, and the Kalman filter method to achieve real-time monitoring of battery charge. The ampere-hour integration method estimates SOC by integrating the battery's charge and discharge current over time, accumulating the amount of charge flowing through the current. The open-circuit voltage method, based on the corresponding relationship between the battery's open-circuit voltage and SOC, determines SOC by measuring the battery's open-circuit voltage after it has been left at rest. The Kalman filter utilizes a mathematical model of the battery and real-time measurement data to dynamically estimate and correct SOC using a complex algorithm. These sensors convert the calculated battery SOC into a percentage and transmit it to the power battery derating determination module, enabling the module to monitor the battery's remaining charge in real time. (2) Cell temperature data collection Battery cell temperature sensors typically use thermistors, whose resistance exhibits a significant nonlinear variation with temperature. As the cell temperature rises, the thermistor's resistance decreases; as the temperature drops, it increases. The sensor converts this resistance change into a voltage or current signal through circuitry, which is then transmitted to the power battery derating determination module. To more comprehensively and accurately reflect the cell temperature, multiple temperature sensors are deployed at key locations in the battery pack. The module receives data from these sensors and performs comprehensive analysis to determine the overall cell temperature. 2. Establishment of a two-dimensional lookup table for power battery derating coefficients Establishing a two-dimensional lookup table for power battery derating factors requires extensive experimentation and data accumulation. Engineers simulate the battery under various extreme and standard battery state of charge (SOC) and cell temperature combinations in a laboratory environment. Under low-battery, high-temperature conditions, as battery power continues to deplete, the cell temperature continues to rise, and the chemical reactions within the battery intensify, seriously affecting the battery's charge and discharge performance and potentially even causing safety issues. At this point, gradually increase the battery's charge and discharge current to monitor performance indicators such as battery voltage, internal resistance, charge and discharge efficiency, and thermal runaway risk. If certain indicators are found to exceed safety thresholds, such as a sharp increase in battery internal resistance, a significant decrease in charge and discharge efficiency, or early signs of thermal runaway, the battery's charge and discharge power needs to be derated, and the appropriate power battery derating factor for that battery state of charge (SOC) and cell temperature combination needs to be recorded. Under high-power, low-temperature conditions, low temperatures slow the diffusion of lithium ions within the battery, reducing the battery's available capacity and limiting its charge and discharge capabilities. Similarly, by simulating different charge and discharge conditions and monitoring battery performance, we can determine the corresponding derating factor. After testing a large number of different operating conditions, the battery state of charge (SOC), cell temperature, and corresponding power battery derating factors were organized into a two-dimensional table. Battery state of charge (SOC) is one dimension, cell temperature is another, and each intersection corresponds to a specific power battery derating factor, thus establishing a corresponding relationship between the three. 3. Coefficient query method When the power battery derating determination module receives real-time data indicating a battery SOC of M% and a cell temperature of N degrees Celsius, it begins a two-dimensional table lookup. The module first searches the two-dimensional table for the battery SOC and cell temperature data points that are closest to M% and N degrees Celsius. Because the actual collected data often doesn't exactly match the pre-set data points in the two-dimensional table, the module typically uses a bilinear interpolation algorithm to estimate the power battery derating factor. The bilinear interpolation algorithm requires finding four adjacent data points related to the collected data—the four intersections corresponding to two adjacent battery SOC values ​​and two adjacent cell temperature values. Based on the power battery derating factors corresponding to these four points, linear interpolation is first performed in the battery SOC direction to obtain two intermediate values. These two intermediate values ​​are then linearly interpolated in the cell temperature direction, ultimately estimating the power battery derating factor B corresponding to the actual collected battery SOC of M% and cell temperature of N degrees Celsius. After obtaining derating factor B, the module transmits it to the battery management system, which adjusts battery parameters such as charge and discharge current and voltage based on the derating factor to achieve derating operation of the power battery and ensure safe and stable operation.

[0035] (IV) Generation of derating coefficients, as follows: Based on the collected or calculated information, the derating factor calculation module multiplies the engine derating factor A and the power battery derating factor B to obtain a preliminary derating factor value, A*B. This value is then range-limited to ensure it is between 0 and 1. If the value of A*B is less than 0, the derating factor is set to 0; if greater than 1, it is set to 1; if it is between 0 and 1, the calculated value is retained as the final derating factor C.

[0036] (V) Corrected requested torque calculation The torque correction module calculates a revised requested torque value based on the final derating factor C and the original requested torque X, using the formula "Revised requested torque = X * C." Finally, this revised torque command is sent to the power source execution module (engine and electric motor), adjusting vehicle power output. This allows the driver to proactively perceive the reduction in vehicle power and optimize acceleration expectations.

[0037] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention; therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is limited by the appended claims rather than the above description. Therefore, it is intended that all changes that fall within the meaning and scope of the equivalent elements of the claims are included in the present invention, and any figure signs in the claims should not be regarded as limiting the claims involved.

[0038] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for optimizing acceleration expectations of a hybrid vehicle, characterized in that: The specific steps of the method for optimizing the acceleration expectation of hybrid vehicles are as follows: S1: Real-time monitoring of the working status parameters of the engine and power battery; An intake pressure sensor and an intake temperature sensor are set and integrated in the engine intake pipe. The intake pressure sensor monitors the engine intake pressure in real time, and the intake temperature sensor monitors the engine intake temperature. The engine intake pressure and engine intake temperature provide a basis for determining engine derating. Set up a battery capacity sensor and a battery cell temperature sensor. The battery capacity sensor and the battery cell temperature sensor are set at the power battery and are electrically connected to the power battery. The battery capacity sensor measures the power battery state of charge, and the battery cell temperature sensor monitors the power battery cell temperature in real time. The power state of charge and the battery cell temperature are key parameters for determining power battery derating. S2: Perform power derating determination based on the operating status parameters of the engine and power battery; An accelerator pedal position sensor and a vehicle speed sensor are also provided. The accelerator pedal position sensor obtains information on the degree of opening of the accelerator pedal by the driver to determine the driver's original requested torque. The vehicle speed sensor monitors the vehicle's speed in real time and uses this information together with the accelerator pedal opening information to determine the original requested torque. The intake pressure sensor, intake temperature sensor, battery charge sensor, cell temperature sensor, accelerator pedal position sensor, and vehicle speed sensor are connected to the vehicle control unit. The vehicle control unit, as the core control component, receives data from each sensor, processes and analyzes the data, and makes power derating judgments. S3: Generate corresponding derating factor; S4: The torque requested by the driver through the accelerator pedal is corrected in the vehicle control software so that the driver can sense the reduction in vehicle power in advance and send control instructions to the power source at the same time.

2. The method for optimizing acceleration expectation of a hybrid vehicle according to claim 1, characterized in that: The vehicle control unit integrates an accelerator pedal MAP module, an engine derating determination module, a power battery derating determination module, a derating coefficient calculation module and a torque correction module.

3. The method for optimizing acceleration expectation of a hybrid vehicle according to claim 2, characterized in that: The accelerator pedal MAP module determines the driver's original requested torque based on the collected accelerator pedal opening and vehicle speed information. The accelerator pedal MAP module has a built-in mapping table of the corresponding relationship between accelerator pedal opening and original requested torque. It searches and outputs the corresponding original requested torque value through the real-time collected accelerator pedal opening and vehicle speed information.

4. The method for optimizing acceleration expectation of a hybrid vehicle according to claim 3, characterized in that: The engine derating determination module has a built-in two-dimensional lookup table based on engine characteristics and test data. The engine derating determination module receives intake pressure and intake temperature information, and determines the engine derating coefficient by querying the two-dimensional lookup table of the engine derating coefficient.

5. The method for optimizing acceleration expectation of a hybrid vehicle according to claim 4, characterized in that: The power battery derating determination module has a built-in two-dimensional lookup table, which is constructed based on the performance characteristics of the power battery and a large amount of test data. The corresponding derating coefficient is accurately obtained based on the battery status parameters. The power battery derating determination module obtains battery power and battery cell temperature information, and calculates the power battery derating coefficient through the two-dimensional lookup table of the power battery derating coefficient.

6. The method for optimizing acceleration expectation of a hybrid vehicle according to claim 5, characterized in that: The derating coefficient calculation module multiplies the engine derating coefficient and the power battery derating coefficient and obtains the final derating coefficient through range restriction, and the range is restricted between 0-1.

7. The method for optimizing acceleration expectation of a hybrid vehicle according to claim 6, characterized in that: The torque correction module: according to the final derating factor and the original requested torque, according to the correction calculation formula: Corrected requested torque = original requested torque * final derating factor; The corrected requested torque is calculated and sent to the engine and electric motor.

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