Energy recovery method, computer system, readable storage medium and program product

Abstract

The invention provides an energy recovery method, a computer system, a readable storage medium and a program product. The energy recovery method comprises the following steps that the current mass of a vehicle is calculated; setting an energy recovery torque for electrical braking based on the current mass of the vehicle; and executing an energy recovery operation based on the energy recovery torque. The technical scheme has the advantages of being simple in structure, easy to implement, convenient to use and the like, the energy recovery efficiency of the electric vehicle can be remarkably improved, the endurance is prolonged, and the user experience during braking is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of vehicle control. More specifically, the present application relates to an energy recovery method for an electric vehicle, which aims to improve energy recovery efficiency and user experience. The present application also relates to a computer system, a computer-readable storage medium and a computer program product. BACKGROUND

[0002] An electric vehicle can perform energy recovery simultaneously when decelerating or braking, for example, part of the vehicle kinetic energy is recovered to reversely charge the power battery, thereby reducing energy consumption and prolonging the endurance of the electric vehicle. In this process, the electric vehicle will recover energy through recovery torque. The size of this recovery torque can affect the braking effect of the vehicle and the energy recovery efficiency. In the prior art, the maximum value of the recovery torque is usually fixed, for example, it can be set at the factory and executed by the vehicle control unit. SUMMARY

[0003] An object of one aspect of the present application is to provide an energy recovery method for an electric vehicle, which can effectively improve energy recovery efficiency and user experience. Another object of the present application is to provide a computer system, a computer-readable storage medium and a computer program product to implement the above-mentioned energy recovery method.

[0004] The object of the present application is achieved by the following technical solutions: An energy recovery method for an electric vehicle, comprising the following steps: calculating the current mass of the vehicle; setting an energy recovery torque for electric braking based on the current mass of the vehicle; and performing an energy recovery operation based on the energy recovery torque.

[0005] A computer system comprising a memory, a processor and a computer program stored on the memory, wherein the processor executes the above-mentioned computer program to implement the steps of the above-mentioned energy recovery method for an electric vehicle.

[0006] A computer-readable storage medium having a computer program stored thereon, wherein the computer program is executed by a processor to implement the steps of the above-mentioned energy recovery method for an electric vehicle.

[0007] A computer program product comprising a computer program, wherein the computer program is executed by a processor to implement the steps of the above-mentioned energy recovery method for an electric vehicle. BRIEF DESCRIPTION OF DRAWINGS

[0008] The present application will be further described in detail below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art will appreciate that these drawings are drawn for the purpose of explaining the preferred embodiments only and therefore should not be construed as limiting the scope of the present application. Furthermore, unless specifically indicated, the drawings are intended only to conceptually represent the composition or structure of the described objects and may contain exaggerated representations. The drawings are also not necessarily drawn to scale.

[0009] Figure 1 This is a flowchart of one embodiment of the energy recovery method of this application.

[0010] Figure 2 yes Figure 1 A partial flowchart of the embodiment shown.

[0011] Figure 3 This is a diagram illustrating the forces acting on the vehicle. Detailed Implementation

[0012] Preferred embodiments of this application will now be described in detail with reference to the accompanying drawings. Those skilled in the art will appreciate that these descriptions are merely descriptive and exemplary and should not be construed as limiting the scope of protection of this application.

[0013] First, it should be noted that the directional terms such as top, bottom, upward, and downward mentioned in this article are defined relative to the directions shown in the various accompanying figures. These directions are relative concepts and will therefore vary depending on their location and state. Therefore, these or other directional terms should not be construed as restrictive.

[0014] Furthermore, it should be noted that any single technical feature described or implied in the embodiments herein, or any single technical feature shown or implied in the accompanying drawings, can be further combined to obtain other embodiments not directly mentioned herein.

[0015] It should be noted that in different figures, the same reference numerals denote the same or substantially the same parts.

[0016] Figure 1 and Figure 2 An embodiment of the energy recovery method for electric vehicles according to this application is illustrated. The energy recovery method of this application can be used in electric vehicles, such as vehicles powered by lithium batteries or hydrogen fuel cells, hybrid vehicles, etc. Figure 1 As shown, in one embodiment, the energy recovery method for electric vehicles of this application may include the following steps: Step 100: Calculate the current mass of the vehicle; Step 200: set an energy recovery torque for electric braking based on the current mass of the vehicle; and Step 300: perform an energy recovery operation based on the energy recovery torque.

[0017] In one embodiment, the energy recovery torque for electric braking can be proportional to the current mass of the vehicle. In one embodiment, the energy recovery operation is performed by electric braking force. By providing different energy recovery torques for different current masses of the vehicle, the energy recovery efficiency can be effectively improved, the endurance of the vehicle can be improved, and the user experience can be improved.

[0018] Figure 2 Further details of step 100 are shown. Specifically, in Figure 2 In the embodiment shown, the calculation of the current mass of the vehicle is as follows: Step 110: calculate the current mass of the vehicle by dividing the derivative of driving force by the derivative of acceleration; Step 120: determine whether one or more predetermined conditions are met; Step 130: in the case where all of the one or more predetermined conditions are met (path identified as Y in Figure 2 Step 140: in the case where any one of the predetermined conditions is not met (path identified as N in Step 140: in the case where any one of the predetermined conditions is not met (path identified as N in Figure 2 Step 140: in the case where any one of the predetermined conditions is not met (path identified as N in

[0019] In one embodiment, the calculation process of step 110 is to divide the derivative of driving force with respect to time by the derivative of acceleration with respect to time. In one embodiment, the calculation process of step 110 is to divide the change in driving force in a predetermined time interval by the change in acceleration in the predetermined time interval. The predetermined time interval can be set to be small enough so that the changes in other physical quantities that affect the vehicle, in addition to the changes in driving force and acceleration, are significantly smaller in order of magnitude than the changes in driving force and acceleration, and thus the changes in other physical quantities that affect the vehicle are negligible. In other words, in a sufficiently small predetermined time interval, the vehicle can be approximately regarded as being affected only by the change in driving force and the change in acceleration. In this case, the driving force values and the acceleration values at the beginning and the end of the time interval can be used to approximately calculate the slope relationship of driving force-acceleration. The specific calculation details will be described in detail below.

[0020] One embodiment of the present application makes the determination of a plurality of predetermined conditions in step 120. The plurality of predetermined conditions include, but are not limited to, whether the driving force, the acceleration, and the derivative of the driving force and the acceleration with respect to time have the same direction; whether the absolute values of the driving force, the acceleration, and the derivative of the driving force and the acceleration with respect to time are within a predetermined range; whether the vehicle speed is within a predetermined range; whether the current mass of the vehicle is within a predetermined range; whether the reliability of the signal input meets the requirement; whether the driving mode of the vehicle allows energy recovery; and whether there is a mechanical braking force, etc. One or more of the above predetermined conditions can be selected to participate in the determination in step 120. When all the selected predetermined conditions are met, step 120 can give a determination that the predetermined conditions are met. When any one of the selected predetermined conditions is not met, step 120 can give a determination that the predetermined conditions are not met.

[0021] In the above predetermined condition determination, whether the driving force, the acceleration, and the derivative of the driving force and the acceleration with respect to time have the same direction means that, in order to implement the energy recovery method for electric vehicles disclosed in the present application, the driving force and the acceleration should have the same direction, and the derivative of the driving force and the acceleration with respect to time should also have the same direction at the same time. The same direction can be increasing at the same time or decreasing at the same time. The purpose of this predetermined condition determination is to avoid the possibility that the reverse change of the driving force and the acceleration can cause the positive and negative changes of the slope and the gradient in the driving force-acceleration relationship curve, and such positive and negative changes can cause the calculation of the current mass of the vehicle to be inaccurate.

[0022] In the above predetermined condition determination, whether the absolute values of the driving force, the acceleration, and the derivative of the driving force and the acceleration with respect to time are within a predetermined range means that the driving force needs to be greater than a predetermined threshold value, for example, there is a difference in the order of magnitude between various resistances, so that the neglect of the resistance in the physical model will not have a significant impact on the mass calculation. The acceleration needs to be within a predetermined range to avoid the significant impact of too small acceleration and too large acceleration on the calculation result of the mass. The absolute values of the derivative of the driving force and the acceleration with respect to time need to be greater than a predetermined threshold value, respectively, which makes the derivative of the driving force with respect to time large enough, or in other words, significant enough, to ensure the accuracy of the calculation structure of the current mass of the vehicle.

[0023] In the above predetermined condition determination, whether the vehicle speed is within a predetermined range means that the current speed of the vehicle needs to be within a predetermined range. Such design is because, when the vehicle speed is high, the air resistance increases and can increase to an extent that cannot be ignored. The calculation method of the present application aims to avoid the error caused by the increase of the air resistance due to the too large vehicle speed.

[0024] In the aforementioned determination of predetermined conditions, whether the current vehicle mass is within the predetermined range refers to the fact that the current vehicle mass calculated in step 110 should be within a reasonable range. For example, a vehicle is known to have a certain mass, a certain maximum rated load, and a certain range of mass variation during its design and manufacture. Depending on different vehicle designs, it is possible to obtain a reasonable range of current vehicle mass. When the calculation result contradicts the reasonable range of current vehicle mass, the calculation method of this application aims to avoid using unreasonable calculation results as the current vehicle mass.

[0025] In the aforementioned predetermined condition determination, whether the reliability of the signal input meets the requirements refers to whether the signal inputs of the various sensors on which the calculation depends are reliable. If the vehicle control unit gives a judgment that one or more of the signal inputs are unreliable, it prevents the calculation from being performed using unreliable signal inputs. The calculation method of this application aims to avoid using the result calculated from unreliable signal inputs as the current mass of the vehicle. In one embodiment, acceleration can be calculated based on the sensing results of a speed sensor.

[0026] In the aforementioned predetermined condition determination, whether the vehicle driving mode allows energy recovery refers to whether the current operating state of the vehicle system or the driving mode allows updating the vehicle's current mass and performing subsequent electric braking operations. If the current permitted state or the conditions given by the driving mode do not allow it, then the vehicle's current mass value will not be updated. This setting aims to give the vehicle system the authority to adjudicate the energy recovery method of this application, thereby controlling the scope of application of the energy recovery method of this application.

[0027] In the aforementioned determination of predetermined conditions, the presence or absence of mechanical braking force refers to determining whether the vehicle is currently undergoing mechanical braking. Mechanical braking is likely to originate from the driver's action of pressing the pedal, and therefore has higher authority. When mechanical braking force is present, the vehicle should primarily aim for braking to ensure safety. Therefore, the energy recovery method of this application is configured to update the vehicle's current mass only when mechanical braking force is absent.

[0028] Figure 3 This illustrates an example of the forces acting on a vehicle during operation. The following will combine... Figure 3 This paper details the calculation of the vehicle's current mass in the energy recovery method of this application.

[0029] First, the driving force F of the vehicle can be calculated based on the output torque T of the vehicle's electric motor. The specific calculation process can be tailored to the specific conditions of different vehicles. In one embodiment, the driving force F can be calculated using the following formula: F = T·V t ·r Where F is the driving force, T is the output torque of the electric motor, and V is the torque of the electric motor.t For the efficiency of the transmission system, and r is the rolling radius of the wheel.

[0030] Secondly, according to Newton's second law, there can be the following relationship between the driving force F and the acceleration a: F = m·a + F g + F f + F w Where F is the driving force, m is the current mass of the vehicle, a is the acceleration, F g is the component of the vehicle's gravity in the direction of travel, F f is the friction between the vehicle and the ground, and F w is the air resistance experienced by the vehicle.

[0031] Figure 3 The forces acting on the vehicle during uphill travel to the left are shown. In Figure 3 , the vehicle 10 is driving on a slope 20, the driving direction is uphill or to the left, and the slope 20 has a slope angle of a. In Figure 3 the case shown, the above force formula can be further written as: Where F is the driving force, m is the current mass of the vehicle, a is the acceleration, g is the acceleration of gravity, μ is the rolling friction coefficient between the wheel and the slope, a is the slope angle or slope, C w is the air resistance coefficient, A is the projected area in the direction of travel or the windward area, p is the air density, and v is the speed of the vehicle relative to the air. In Figure 3 , the gravity G of the vehicle provides a component F g in the direction of travel and a component F s perpendicular to the road surface. There is the following relationship between them: F g = G·sin a = m·g·sin a F s = G·cos a = m·g·cos a The above formulas can also be rewritten in other forms according to the actual working conditions, which will not be described herein. According to the way disclosed in the present application, the force formula when the vehicle is driving downhill or on a horizontal surface can also be written, which will not be described herein.

[0032] In the energy recovery method of the present application, when the driving force F and the acceleration a are large enough, and in a small enough time interval, F g , F f and F w can be regarded as constant and can be regarded as a constant. Therefore, the above formula is simplified as: F = m·a + C where F is the driving force, m is the current mass of the vehicle, a is the acceleration, and C is a constant.

[0033] Taking the derivative of both sides of the above equation with respect to time, we have: Further, we have the following simplified result: Therefore, in the energy recovery method of the present application, the current mass m of the vehicle can be roughly estimated by the change in driving force and the change in acceleration within a sufficiently small time interval.

[0034] During the operation of the vehicle, the current mass of the vehicle can be continuously calculated according to the energy recovery method of the present application. If the conditions are met, the newly calculated current mass of the vehicle will replace the previous current mass of the vehicle for energy recovery operation. At the time of delivery, the vehicle can be provided with an initial current mass of the vehicle. In addition, the calculation of the current mass of the vehicle can also be performed as needed, for example, in the case of a driver request or in the case of a vehicle control unit request. The present application is not limited to a specific situation, but different implementations can be obtained according to the actual situation.

[0035] The present application also relates to a computer system comprising a memory, a processor, and a computer program stored on the memory, wherein the processor executes the above computer program to implement the steps of the above energy recovery method for electric vehicles. In one embodiment, the processor can be a vehicle control unit. In one embodiment, the memory can be a memory provided on the vehicle.

[0036] The present application also relates to a computer-readable storage medium having a computer program stored thereon, wherein the computer program is executed by a processor to implement the steps of the above energy recovery method for electric vehicles. In one embodiment, the processor can be a vehicle control unit. In one embodiment, the computer-readable storage medium can be a computer-readable storage medium provided on the vehicle.

[0037] The present application also relates to a computer program product comprising a computer program, wherein the computer program is executed by a processor to implement the steps of the above energy recovery method for electric vehicles. In one embodiment, the processor can be a vehicle control unit.

[0038] The energy recovery method, computer system, readable storage medium, and program product of the present application can have the advantages of being simple and reliable, easy to implement, convenient to use, etc., and can significantly improve the energy recovery efficiency of electric vehicles, prolong the endurance and improve the user experience during braking.

[0039] The present application is disclosed herein with reference to the attached drawings, and will be made apparent by reference to the drawings and the following detailed description, and will be made apparent by reference to the drawings and the following detailed description, and will be made apparent by reference to the drawings and the following detailed description, and will be made apparent by reference to the drawings and the following detailed description, and will be made apparent by reference to the drawings and the following detailed description, and will be made apparent by reference to the drawings and the following detailed description, and will be made apparent by reference to the drawings and the following detailed description, and will be made apparent by reference to the drawings and the following detailed description, and will be made apparent by reference to the drawings and the following detailed description, and will be made apparent by reference to the drawings and the following detailed description, and will be made apparent by reference to the drawings and the following detailed description, and will be made apparent by reference to the drawings and the following detailed description, and will be made apparent by reference to the drawings and the following detailed description, and will be made apparent by reference to the drawings and the following detailed description, and will be made apparent by reference to the drawings and the following detailed description, and will be made apparent by reference to the drawings and the following detailed description, and will be made apparent by reference to the drawings and the following detailed description, and will be made apparent by reference to the drawings and the following detailed description, and will be made apparent by reference

Claims

1. An energy recovery method for electric vehicles, characterized in that, Includes the following steps: Calculate the current mass of the vehicle; Based on the current mass of the vehicle, the energy recovery torque for electric braking is set; and Based on the energy recovery torque, an energy recovery operation is performed.

2. The energy recovery method according to claim 1, characterized in that, The energy recovery torque is set to be proportional to the current mass of the vehicle.

3. The energy recovery method according to claim 1, characterized in that, The current mass of the vehicle is determined using the following method: When predetermined conditions are met, the current mass of the vehicle is set to be equal to the derivative of the driving force divided by the derivative of the acceleration; When the predetermined conditions are not met, the current mass of the vehicle is set to be equal to the current mass of the previous vehicle.

4. The energy recovery method according to claim 3, characterized in that, The predetermined conditions include one or more of the following conditions: The driving force, the acceleration, and their derivatives with respect to time have the same direction; Do the values ​​of the driving force, the acceleration, and the absolute values ​​of their derivatives with respect to time satisfy predetermined conditions? Is the vehicle speed within the predetermined range? as well as Is the current weight of the vehicle within the predetermined range? 5. The energy recovery method according to claim 4, characterized in that, The predetermined conditions also include one or more of the following conditions: Does the signal input reliability meet the requirements? Does the vehicle's driving mode allow energy recovery? Does mechanical braking force exist? 6. The energy recovery method according to claim 4, characterized in that, The value of the driving force needs to be greater than a predetermined threshold, the value of the acceleration needs to be within a predetermined range, and / or the absolute values ​​of the derivatives of the driving force and the acceleration with respect to time need to be greater than predetermined thresholds respectively.

7. The energy recovery method according to claim 3, characterized in that, When predetermined conditions are met, the current mass of the vehicle is set to be equal to the change in driving force over a predetermined time interval divided by the change in acceleration over the predetermined time interval.

8. The energy recovery method according to any one of claims 4-7, characterized in that, The driving force is calculated based on the output torque of the drive motor, and the acceleration is based on the sensing results of the speed sensor.

9. A computer system comprising a memory, a processor, and a computer program stored in the memory, characterized in that, The processor executes the computer program described above to implement the steps of the energy recovery method for electric vehicles according to any one of claims 1-8.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the energy recovery method for electric vehicles as described in any one of claims 1-8.

11. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the energy recovery method for electric vehicles as described in any one of claims 1-8.

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