Pure electric vehicle energy recovery control method and system

Abstract

The invention discloses an energy recovery control method and system for a pure electric vehicle, and the method comprises the steps: monitoring the stroke signals of an accelerator pedal and a brake pedal in real time in the running process of the vehicle; and the vehicle control unit calculates the initial energy recovery strength after the accelerator pedal is released according to the factory energy recovery size parameters and the collected set reference of the user, and sends the braking torque corresponding to the initial energy recovery strength to the motor controller so as to be matched with the braking torque in a motor energy recovery mode. The pure electric vehicle energy system has the advantages that the independently-adjustable pure electric vehicle energy system distinguishes the brake pedal stepping working condition and the accelerator pedal loosening working condition, the energy recovery intensity can be automatically adjusted in real time to improve the whole vehicle driving feeling while the traditional driving habit is met, and brake energy is recovered to the maximum extent.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of new energy vehicle energy recovery, in particular to a pure electric vehicle energy recovery control method and system capable of real-time autonomous adjustment. BACKGROUND

[0002] The energy recovery system is one of the important components of the new energy electric vehicle, and is very important for improving the vehicle endurance. In the prior art, the single pedal mode is used for energy recovery. The single pedal mode uses the energy recovery system to recover energy at the maximum amplitude. During driving, when the driver releases the accelerator pedal to a certain extent, the vehicle enters the energy recovery system to recover energy while reducing the vehicle speed to achieve the purpose of vehicle braking. The advantage of this design is that the braking energy can be recovered at the maximum amplitude to improve the vehicle endurance and reduce the wear of the brake pads to increase the service life of the brake pads. The disadvantage is that the single pedal mode is easy to mistake the accelerator as a brake, thereby causing serious traffic accidents. The energy recovery intensity is large, the recovery intensity cannot be adjusted, the braking deceleration is large, and the driving comfort is greatly reduced. Long-time driving will cause dizziness and other discomfort.

[0003] In the prior art, there are other schemes for adjusting the energy recovery intensity. The energy recovery level is divided into high, medium and low gears. The energy recovery intensity of the high gear is generally large, and the driving comfort is not high. The energy recovery of the medium gear is moderate, but it cannot cover the driving feelings of all people. The energy recovery of the low gear is small, and the brake energy consumption is wasted, which wears the brake pads. SUMMARY

[0004] The purpose of the present application is to overcome the shortcomings of the prior art and provide a pure electric vehicle energy system capable of autonomous adjustment. The energy recovery intensity is adjusted in real time to improve the driving feeling of the whole vehicle and recover the braking energy at the maximum amplitude while conforming to the traditional driving habits.

[0005] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows: a pure electric vehicle energy recovery control method, comprising monitoring the stroke signals of the accelerator pedal and the brake pedal in real time during vehicle driving, calculating the initial energy recovery intensity after the accelerator pedal is released according to the factory energy recovery size parameter and the user's setting reference collected when it is detected that the accelerator pedal is released, and sending the brake torque corresponding to the initial energy recovery intensity to the motor controller to match the brake torque through the motor energy recovery mode.

[0006] The factory energy recovery size is calibrated in advance through experiments. The steady sliding motor braking is used as the benchmark to calibrate the experiment under the whole vehicle sliding condition to obtain the braking data matched by the factory energy recovery size.

[0007] The user's setting parameter is superimposed on the factory energy recovery size parameter to obtain the final starting energy recovery intensity after the vehicle is started.

[0008] The user's setting parameter is superimposed on the factory energy recovery size parameter to obtain the final starting energy recovery intensity after the vehicle is started.

[0009] The travel signal of the brake pedal is collected in real time, and the starting energy recovery intensity is always used to brake and recover energy when the accelerator pedal is released and the brake pedal is not stepped on.

[0010] When it is detected that the brake pedal is stepped on, the pedal travel is monitored in real time, and when the pedal travel is less than the travel threshold, only the braking torque is increased by increasing the energy recovery intensity to brake, and the energy recovery intensity is increased or decreased according to the size of the brake pedal travel from the starting energy recovery intensity.

[0011] When it is detected that the brake pedal is stepped on, if the brake pedal exceeds the travel threshold, the vehicle is braked according to the pedal travel in the combined mode of energy recovery braking and hydraulic braking.

[0012] After the brake pedal travel exceeds the travel threshold, in the case of increasing travel, the hydraulic braking increases and the energy recovery gradually decreases, and the increasing speed of the hydraulic braking is greater than the decreasing rate of the energy recovery braking.

[0013] The hydraulic braking size and the energy recovery size calculated according to the pedal travel after the pedal travel are obtained by pre-calibration, and the hydraulic braking deceleration and the electric braking deceleration corresponding to different brake travels of the vehicle brake working condition are calibrated by pre-test to form a comparison table, and the hydraulic braking size and the energy recovery size are confirmed by the comparison table during brake control.

[0014] An energy recovery control system for a pure electric vehicle, comprising a vehicle-mounted large screen, a multifunctional steering wheel, an accelerator pedal, a brake pedal, a pedal travel switch, a vehicle controller, and a motor controller; the vehicle-mounted large screen is used to realize the function of adjusting the initial intensity of energy recovery, and transmits information to the vehicle controller through can communication; the multifunctional steering wheel plus-minus key is used to adjust the size of energy recovery in real time; the pedal travel switch collects the brake pedal travel at all times and transmits it to the vehicle controller through a hard-wire voltage signal; the vehicle controller receives the energy recovery intensity signal transmitted by the large screen, the accelerator pedal signal, the multifunctional steering wheel signal, and the brake pedal travel signal, and comprehensively calculates the braking force required for energy recovery, and transmits it to the motor controller through can communication, and the motor controller receives the braking torque to control the driving motor to realize braking and energy recovery.

[0015] The advantages of the application are that the self-adjustable pure electric vehicle energy system can distinguish the brake pedal working condition and the throttle pedal, formulate the traditional driving habit, and can self-adjust the energy recovery strength in real time to improve the vehicle driving feeling and recover the braking energy with the maximum amplitude.

[0016] 1. Using double pedals (brake pedal and throttle pedal) can meet the traditional driving habit, and the throttle pedal is not easy to be mistaken as brake pedal, which improves the driving safety performance;

[0017] 2. The energy recovery strength can be adjusted in real time to meet the driving comfort requirements of all people and improve the vehicle driving feeling;

[0018] 3. The energy recovery can be realized with the maximum amplitude, the driver can control the energy recovery size according to the braking distance, and the vehicle endurance is improved. BRIEF DESCRIPTION OF DRAWINGS

[0019] The contents expressed by each figure in the specification of the application and the marks in the figure are briefly described as follows:

[0020] Figure 1 It is an energy recovery system architecture diagram;

[0021] Figure 2 It is an energy recovery initial strength diagram of a vehicle-mounted large screen;

[0022] Figure 3 It is a brake working condition hydraulic brake / electric brake deceleration calibration diagram;

[0023] Figure 4 It is a brake working condition total deceleration diagram;

[0024] Figure 5 It is a coasting working condition factory setting electric brake deceleration calibration diagram;

[0025] Figure 6 It is an energy recovery system flow chart. DETAILED DESCRIPTION

[0026] The specific embodiments of the application are further described in detail below by comparing the drawings and describing the optimal embodiments.

[0027] The energy recovery control method of the application completes energy recovery on the basis of meeting user braking, adopts double pedal mode for energy recovery braking, solves the safety hidden trouble caused by the single pedal in the prior art, provides a user self-adjusting mode, can adjust the energy recovery strength according to user demand, and can increase hydraulic braking after the pedal is stepped down, thereby improving the reliability of the whole braking, suitable for emergency braking working condition, and improving safety.

[0028] The embodiment provides a pure electric vehicle energy recovery control method, which comprises the following steps: monitoring the stroke signals of the accelerator pedal and the brake pedal in real time during vehicle driving; when it is detected that the accelerator pedal is released, the vehicle controller calculates the starting energy recovery intensity after the accelerator pedal is released according to the factory energy recovery size parameter and the user's setting reference collected, and sends the brake torque corresponding to the starting energy recovery intensity to the motor controller to match the brake torque through the motor energy recovery mode.

[0029] The factory energy recovery size is calibrated through experiments, and the factory energy recovery size is calibrated to obtain the brake data matched by the factory energy recovery size under the condition of smooth sliding motor braking in the vehicle sliding condition. The factory size is calibrated to meet the needs of ordinary people for energy recovery braking. After the vehicle is started, the user's setting parameter for energy recovery is collected, and the user's setting parameter is superimposed on the factory energy recovery size parameter to obtain the final starting energy recovery intensity. The energy recovery intensity at the factory belongs to the initial setting parameter, and the brake energy recovery size cannot meet the needs of all drivers, so the driver's setting parameter is set, and the driver increases or reduces the energy recovery intensity according to the actual demand to meet the individual needs.

[0030] In the embodiment, the user's setting parameter adopts the multifunctional steering wheel plus-minus key to increase or decrease the energy recovery and obtain the increase or decrease ratio, and the ratio is applied to the factory energy recovery size parameter. The increase or decrease button is set on the steering wheel, the energy recovery intensity at the factory is increased or decreased by triggering the case to form the initial starting energy recovery size, and the energy recovery braking is performed based on the energy recovery size.

[0031] When the energy recovery braking control is performed, the stroke signal of the brake pedal is collected in real time, the starting energy recovery intensity corresponding brake torque is always used for braking and energy recovery when the accelerator pedal is released and the brake pedal is not stepped on. When it is detected that the brake pedal is stepped on, the pedal stroke is monitored in real time, and when the pedal stroke is less than the stroke threshold, only the brake torque is increased by increasing the energy recovery intensity to brake, and the energy recovery intensity is increased or decreased from the starting energy recovery intensity according to the brake pedal stroke size. After it is detected that the brake pedal is stepped on, if the brake pedal exceeds the stroke threshold, the vehicle is braked in the combined mode of energy recovery braking and hydraulic braking according to the pedal stroke. After the brake pedal stroke exceeds the stroke threshold, the hydraulic braking increases and the energy recovery gradually decreases with the increase of the stroke; wherein the increase speed of the hydraulic braking is greater than the decrease rate of the energy recovery braking.

[0032] The hydraulic brake size and the energy recovery size calculated according to the pedal stroke beyond the pedal stroke are obtained by pre-calibration. The hydraulic brake deceleration and the electric brake deceleration corresponding to different brake strokes of the vehicle brake working condition are calibrated by pre-test, so as to form a comparison table. The hydraulic brake size and the energy recovery size are confirmed by the comparison table during brake control.

[0033] The hardware system components involved in the energy recovery control scheme in the embodiment include a vehicle-mounted large screen, a multifunctional steering wheel, an accelerator pedal, a brake pedal, a pedal stroke switch, a vehicle controller, and a motor controller. The vehicle-mounted large screen is used to realize the function of adjusting the initial strength of energy recovery, and information is transmitted to the vehicle controller through a can communication mode. The plus and minus keys of the multifunctional steering wheel are used to adjust the size of energy recovery in real time. The pedal stroke switch collects the brake pedal stroke at all times and transmits the voltage signal to the vehicle controller through a hard line. The vehicle controller receives the energy recovery strength signal transmitted by the large screen, the accelerator pedal signal, the multifunctional steering wheel signal, and the brake pedal stroke signal, and comprehensively calculates the required braking force for energy recovery, which is transmitted to the motor controller through a can communication mode. The motor controller receives the braking torque and controls the driving motor to execute to realize braking and energy recovery.

[0034] In the embodiment, the energy recovery size calibrated by the manufacturer is used for energy recovery during coasting. When the brake pedal is also depressed, the distribution of the braking forces of the energy recovery braking and the hydraulic braking is adjusted through the brake pedal stroke, so as to meet the demand for braking on the basis of ensuring energy recovery.

[0035] In a preferred scheme in the embodiment, in order to solve the problem of dizziness of the driver and the like caused by energy recovery braking, the vehicle is connected to the intelligent wearable device of the driver in the scheme, and the physiological parameters of the driver in the driving process are obtained through the intelligent wearable device. At the same time, the face state data of the driver are obtained through the DMS system of the driver, the driver state of the driver is recognized based on the face state data, and it is judged whether the current energy recovery setting parameter matches the driver based on the face state data and the physiological parameter data. If it is recognized based on the physiological parameters and / or the DMS system that the driver has an abnormal state (such as car sickness, heart rate fluctuation, expression pain, and other driving abnormal states) in the driving process, it is indicated that the energy recovery setting parameter does not match the actual demand of the driver at this time. At this time, a reminder is sent to the driver through the Internet of Vehicles or the vehicle machine IHU. After the driving of the vehicle ends, a reminder signal is sent to the user through the instrument, the multimedia display screen, the Internet of Vehicles mobile phone app, and the like, reminding the user to modify the energy recovery parameter to avoid the problem of driving experience caused by large energy recovery.

[0036] As Figures 1-5As shown, the patent designs a new energy electric vehicle energy recovery system which can be real-time self-adjusting. In order to achieve the above purpose, the application mainly comprises: a vehicle-mounted large screen with touch screen function, a multifunctional steering wheel, a vehicle controller, a brake pedal, a pedal stroke switch, an accelerator pedal, a motor controller and a drive motor.

[0037] The main principle is: firstly, the hydraulic brake deceleration and the electric brake deceleration corresponding to different brake strokes of the vehicle under the brake working condition are calibrated, and the calibration data is given to the vehicle controller; then, the smooth and moderate electric brake deceleration under the vehicle coasting working condition is calibrated, and after the calibration is completed, the coasting electric brake data is given to the vehicle controller, and the data is used as the starting point of the energy recovery size of the vehicle out of the factory, the driver can set the starting point of the coasting energy recovery intensity on the vehicle-mounted large screen and record it as the starting point of the energy recovery size of the driver driving, and the vehicle-mounted large screen transmits the signal to the vehicle controller; the multifunctional steering wheel plus and minus key adjusts the energy recovery size in the coasting process on the basis of the energy recovery size starting point set by the driver; during driving, the driver releases the accelerator, the vehicle controller calculates the required energy recovery according to the recorded energy recovery size out of the factory, the multifunctional steering wheel plus and minus key and the initial energy recovery size set by the driver, and sends the brake torque to the motor controller to control the vehicle brake torque. When the brake is pressed, within a certain brake stroke, only energy recovery is entered, the brake torque is calibrated, and energy recovery is performed, when the brake pedal exceeds a certain stroke, the energy recovery intensity reaches the maximum, the hydraulic brake intervenes, and the emergency braking demand can be met.

[0038] The main steps are:

[0039] 1. Calibrate the hydraulic brake deceleration and electric brake deceleration corresponding to different brake strokes of the vehicle under the brake working condition;

[0040] 2. Calibrate the electric brake deceleration under the coasting working condition;

[0041] 3. The vehicle controller processes the calibration data, the electric brake deceleration corresponds to the electric brake torque, and is used for the energy recovery working condition;

[0042] 4. The driver sets the coasting energy recovery size starting point on the large screen and the multifunctional steering wheel plus and minus key signal is sent to the vehicle controller;

[0043] 5. The vehicle controller receives the energy recovery intensity signal of the large screen, the multifunctional steering wheel plus and minus key signal and the brake pedal stroke signal, and comprehensively calculates the required energy recovery intensity, and sends the corresponding brake torque to the motor controller;

[0044] 6. The motor controller receives the brake torque, controls the drive motor to execute the brake torque, and recovers the brake energy.

[0045] For example,Figure 1 As shown in the energy recovery system architecture diagram: the new energy electric vehicle energy recovery system can be autonomously adjusted and mainly consists of a vehicle-mounted large screen, a multifunctional steering wheel, an accelerator pedal, a brake pedal, a pedal stroke switch, a vehicle controller, a motor controller, a drive motor and the like. The vehicle-mounted large screen mainly realizes the function of adjusting the initial strength of energy recovery and transmits information to the vehicle controller through the can communication mode; the plus and minus keys of the multifunctional steering wheel can realize real-time adjustment of the size of energy recovery; the pedal stroke switch collects the brake pedal stroke at all times and transmits the voltage signal to the vehicle controller through a hard line; the vehicle controller receives the energy recovery strength signal, the accelerator pedal signal, the multifunctional steering wheel signal and the brake pedal stroke signal transmitted by the large screen and comprehensively calculates the braking force required for energy recovery according to the calibrated braking force, which is transmitted to the motor controller through the can communication mode, and the motor controller receives the braking torque and controls the drive motor to execute and feed back the electric quantity to the battery.

[0046] As shown in Figure 2 The vehicle-mounted large screen sets the initial strength of energy recovery, which can be adjusted from 0% to 100%, and the initial energy recovery strength is 50% at the factory, and the user can select the appropriate energy recovery strength.

[0047] As shown in Figure 3 The brake working condition hydraulic brake / electric brake deceleration calibration diagram: 0-5mm is the brake pedal idle stroke, which does not produce any braking force;

[0048] 5-40mm is only electric brake, which performs energy recovery;

[0049] 40-maximum stroke is hydraulic brake intervention, the hydraulic brake gradually increases and the electric brake gradually decreases, which can ensure the safety of the vehicle.

[0050] As shown in Figure 4 The brake working condition total deceleration diagram: the driver steps on the brake during driving, and within a certain brake stroke, only energy recovery is entered, which is used for non-emergency braking, and the driver can autonomously judge the brake depth according to the braking distance. After a certain stroke, the energy recovery strength reaches the maximum, and the hydraulic brake intervenes, which is used for emergency braking.

[0051] As shown in Figure 5 The factory setting electric brake deceleration calibration diagram in the coasting working condition: the driver releases the accelerator during driving, which performs energy recovery, and the energy recovery strength at different vehicle speeds can be adjusted on the large screen and memorized. The plus and minus keys on the steering wheel can real-time adjust the strength of energy recovery during coasting.

[0052] As shown in Figure 6 The energy recovery system flowchart: its main steps are as follows:

[0053] 1. Calibrate the hydraulic brake deceleration and electric brake deceleration corresponding to different brake strokes of the vehicle;

[0054] 2. Calibrate the electric brake deceleration in the vehicle coasting condition

[0055] 3. The vehicle controller processes the calibrated data of the electric brake deceleration corresponding to the electric brake torque for the energy recovery condition;

[0056] 4. The on-board large screen sends the initial energy recovery strength / multi-functional steering wheel sends the real-time adjustment signal;

[0057] 5. The vehicle controller receives the energy recovery strength signal of the large screen and the brake pedal stroke signal, comprehensively calculates the required energy recovery strength, and sends the corresponding brake torque to the motor controller;

[0058] 6. The motor controller receives the brake torque instruction, controls the driving motor to execute the brake torque, and recovers the brake energy.

[0059] The present scheme firstly calibrates the hydraulic brake deceleration and electric brake deceleration corresponding to different brake strokes of the vehicle in the brake condition, and gives the calibrated data to the vehicle controller; then calibrates the smooth and moderate coasting electric brake deceleration in the vehicle coasting condition, gives the coasting electric brake data to the vehicle controller after the calibration is completed, and takes the data as the starting point of the energy recovery size of the vehicle out of the factory, the driver can set the coasting energy recovery strength starting point on the on-board large screen and record it as the starting point of the energy recovery size of the driver driving, the on-board large screen transmits the signal to the vehicle controller; the multi-functional steering wheel plus-minus key adjusts the energy recovery size in the coasting process on the basis of the energy recovery size starting point set by the driver; the driver releases the accelerator during driving, the vehicle controller calculates the required energy recovery according to the recorded energy recovery size out of the factory, the multi-functional steering wheel plus-minus key and the initial energy recovery size set by the driver, and sends the brake torque to the motor controller to control the vehicle brake torque. When the brake is pressed, the energy recovery is only entered within a certain brake stroke, the energy recovery is carried out according to the calibrated brake torque, and when the brake pedal exceeds a certain stroke, the energy recovery strength reaches the maximum, the hydraulic brake is involved, and the emergency braking demand can be met.

[0060] Obviously, the specific implementation of the present application is not limited by the above-mentioned manner, as long as various non-essential improvements are made by adopting the method concept and technical scheme of the present application, which are within the protection scope of the present application.

Claims

1. A method for controlling energy recovery in a pure electric vehicle, characterized in that: This includes real-time monitoring of the travel signals of the accelerator pedal and brake pedal during vehicle driving. When it is detected that the accelerator pedal is released, the vehicle controller calculates the starting energy recovery force after the accelerator pedal is released based on the factory energy recovery size parameters and the user's setting reference collected, and sends the braking torque corresponding to the starting energy recovery force to the motor controller to match the braking torque through motor energy recovery.

2. The method for controlling energy recovery of a pure electric vehicle according to claim 1, wherein: The energy recovery size is pre-calibrated through experiments before leaving the factory. Experimental calibration is performed under the coasting condition of the whole vehicle with smooth coasting motor braking as a benchmark to obtain braking data that matches the factory energy recovery size.

3. The energy recovery control method for a pure electric vehicle according to claim 1, wherein: After the vehicle is started, the user's setting parameters for energy recovery are collected, and the user's setting parameters are superimposed on the factory energy recovery size parameters to obtain the final starting energy recovery strength.

4. The method for controlling energy recovery of a pure electric vehicle according to claim 3, wherein: The user sets the parameters using the plus and minus keys on the multi-function steering wheel to increase or decrease the energy recovery and obtain the increase or decrease ratio, and then applies the ratio to the factory energy recovery size parameters.

5. A method for controlling energy recovery in a pure electric vehicle according to any one of claims 1 to 4, characterized in that: The brake pedal travel signal is collected in real time. When the accelerator pedal is released and the brake pedal is not pressed, the braking torque corresponding to the starting energy recovery force is always used for braking and energy recovery.

6. The method for controlling energy recovery of a pure electric vehicle according to claim 5, wherein: When it is detected that the brake pedal is depressed, the pedal stroke is monitored in real time. When the pedal stroke is less than the stroke threshold, braking is performed only by increasing the energy recovery force to increase the braking torque. The energy recovery force increases or decreases from the starting energy recovery force according to the size of the brake pedal stroke.

7. The method for controlling energy recovery of a pure electric vehicle according to claim 6, wherein: After detecting that the brake pedal is depressed, if the brake pedal exceeds the travel threshold, the vehicle is braked by combining energy recovery braking with hydraulic braking according to the pedal travel.

8. The method for controlling energy recovery of a pure electric vehicle according to claim 7, wherein: After the brake pedal stroke exceeds the stroke threshold, as the stroke increases, the hydraulic braking increases and the energy recovery is controlled to gradually decrease; wherein the increase rate of the hydraulic braking is greater than the decrease rate of the energy recovery braking.

9. The method for controlling energy recovery of a pure electric vehicle according to claim 8, wherein: After exceeding the pedal stroke, the hydraulic braking size and energy recovery size calculated according to the pedal stroke are obtained through pre-calibration. The hydraulic braking deceleration and electric braking deceleration corresponding to different braking strokes of the vehicle braking conditions are pre-calibrated through experiments to form a comparison table. During brake control, the hydraulic braking size and energy recovery size are confirmed through the comparison table.

10. A pure electric vehicle energy recovery control system, characterized by: It includes a large on-board screen, a multi-function steering wheel, an accelerator pedal, a brake pedal, a pedal travel switch, a vehicle controller, and a motor controller. The large on-board screen is used to adjust the initial intensity of energy recovery and transmits information to the vehicle controller via CAN communication. The multi-function steering wheel plus and minus buttons are used to adjust the energy recovery in real time; The pedal travel switch collects the brake pedal travel at all times and transmits it to the vehicle controller via a hard-line voltage signal; the vehicle controller receives the energy recovery intensity signal, accelerator pedal signal, multi-function steering wheel signal, and brake pedal travel signal transmitted by the large screen and comprehensively calculates the braking force required for energy recovery, which is transmitted to the motor controller via CAN communication. The motor controller receives the braking torque and controls the drive motor to achieve braking and energy recovery.

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