CN114103659A

CN114103659A - Energy consumption optimization method and control system for electric automobile

Info

Publication number: CN114103659A
Application number: CN202111497615.6A
Authority: CN
Inventors: 李静
Original assignee: Hozon New Energy Automobile Co Ltd
Current assignee: Hozon New Energy Automobile Co Ltd
Priority date: 2021-12-09
Filing date: 2021-12-09
Publication date: 2022-03-01

Abstract

A first state that a vehicle is static and a gear is in a D gear, a second state that the vehicle is static and the gear is in an N gear or a P gear or a third state that the vehicle brakes at a low speed are identified through an electric vehicle control system, and a vehicle control unit requests a power motor and a controller (MCU) assembly to turn off an Insulated Gate Bipolar Transistor (IGBT) through a CAN bus under the corresponding state so as to achieve the effect of reducing the energy consumption of the vehicle. The invention further provides an electric automobile control system.

Description

Energy consumption optimization method and control system for electric automobile

Technical Field

The invention belongs to the field of electric automobiles, and particularly relates to an energy consumption optimization method and a control system of an electric automobile.

Background

With the rapid development of the household electric automobile market, the cruising ability of the electric automobile becomes more and more important performance indexes concerned by consumers and manufacturers. At present, the cost of a power battery in an electric automobile is nearly half, and the market lacks competitiveness due to the fact that the endurance mileage is increased by a method of simply improving the battery capacity. Therefore, optimizing the energy consumption of the whole vehicle and improving the battery management level become a popular subject of the current research in the field of electric vehicles.

At present, a certain gap exists between a traditional NEDC test scene and a practical application scene of a household electric vehicle, and the household electric vehicle can meet more scenes such as slow crawling, short stop, frequent start, sliding deceleration and the like in an actual driving process. This makes many existing energy consumption optimization techniques for NEDC test conditions unsatisfactory. The inventor has recognized that the prior art fails to reduce the static power consumption of the powertrain during short stop or low speed braking conditions, which adversely affects the range of the vehicle.

Disclosure of Invention

The invention aims to provide an energy consumption optimization method and a control system of an electric automobile, so as to reduce energy consumption under the working condition of short-time parking or low-speed braking, improve the cruising ability of the automobile and enable the automobile to be more energy-saving and environment-friendly.

According to one aspect of the embodiment of the invention, the method for optimizing the energy consumption of the electric automobile is used for an electric automobile control system, the electric automobile control system comprises a vehicle control unit, a power motor, an MCU assembly and an IGBT module, and the method utilizes the vehicle control unit to identify the specific working condition of the vehicle; executing an energy consumption optimization step under the specific working condition, wherein the energy consumption optimization step requests the MCU to close the IGBT; the specific working condition comprises a first state that the vehicle is static and the gear is in a D gear, a second state that the vehicle is static and the gear is in an N gear or a P gear, or a third state that the vehicle brakes at a low speed.

In one or more embodiments, in the first state, a brake pedal is depressed, and the vehicle control unit requests the MCU to unload creep torque; and when the vehicle control unit monitors that the brake pedal is released, the MCU is requested to start the IGBT so as to exit from the first state.

In one or more embodiments, the unloading creep torque process unloads the torque to 0 at a gradient for the MCU.

In one or more embodiments, before the energy consumption optimization step is executed in the first state, the vehicle control unit has a determination time, and the vehicle is not started in the determination time, and then sends a request to enter the first state.

In one or more embodiments, the decision time is 1 to 15 seconds.

In one or more embodiments, when the vehicle controller monitors that the vehicle is stationary and switches to the P range or the N range, the second state is identified, and when the vehicle controller monitors that the vehicle is in the D range or the R range, the MCU is requested to start the IGBT to exit the second state.

In one or more embodiments, when a brake pedal is pressed down during the running of the vehicle, the vehicle control unit monitors that the running speed of the vehicle is lower than a critical speed and does not receive an acceleration signal, and identifies the third state; and when the vehicle control unit monitors that the brake pedal is released, requesting the MCU to start the IGBT and exiting from the third state.

In one or more embodiments, the critical speed ranges from 5 to 15 km/h.

In one or more embodiments, the front radar is configured to monitor a vehicle distance ahead, and when the front radar monitors that the vehicle distance ahead is increased, the vehicle control unit is used to request the MCU to exit from the first state, the second state, or the third state.

In one or more embodiments, a meter is also provided that provides an image and/or audible cue when the vehicle enters or exits the first, second or third states.

According to another aspect of the embodiments of the present invention, there is provided an electric vehicle control system configured to perform any one of the above energy consumption optimization methods.

Drawings

FIG. 1 is a schematic diagram of an electric vehicle control system according to an embodiment;

FIG. 2 is a flow chart of a first state in an embodiment;

FIG. 3 is a flow chart of a second state in one embodiment;

FIG. 4 is a flow chart of a third state in an embodiment.

The meaning of the reference numerals:

1-a vehicle control unit; 2-a power motor and an MCU assembly; 3-IGBT; 4-accelerator pedal; 5-a brake pedal; 6-gear controller; 7-instrument; 8-front radar.

It should be noted that the above-mentioned drawings are intended to illustrate the present invention in detail so as to enable those skilled in the art to understand the technical idea of the present invention, and are not intended to limit the embodiments of the present invention.

Detailed Description

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings used in the description of the embodiments will be briefly introduced below. It is obvious that the drawings in the following description are only examples or embodiments of the application, from which the application can also be applied to other similar scenarios without inventive effort for a person skilled in the art. Unless otherwise apparent from the context, or otherwise indicated, like reference numbers in the figures refer to the same structure or operation.

As used in this application and the appended claims, the terms "a," "an," "the," and/or "the" are not intended to be inclusive in the singular, but rather are intended to be inclusive in the plural unless the context clearly dictates otherwise. In general, the terms "comprises" and "comprising" merely indicate that steps and elements are included which are explicitly identified, that the steps and elements do not form an exclusive list, and that a method or apparatus may include other steps or elements.

The relative arrangement of the components and steps, the numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present application unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate.

It should be noted that the terms "first", "second", and the like are used to define the components, and are only used for convenience of distinguishing the corresponding components, and the terms have no special meanings unless otherwise stated, and therefore, the scope of protection of the present application is not to be construed as being limited. Further, although the terms used in the present application are selected from publicly known and used terms, some of the terms mentioned in the specification of the present application may be selected by the applicant at his or her discretion, the detailed meanings of which are described in relevant parts of the description herein. Further, it is required that the present application is understood not only by the actual terms used but also by the meaning of each term lying within.

It will be understood that when an element is referred to as being "on," "connected to," "coupled to" or "contacting" another element, it can be directly on, connected or coupled to, or contacting the other element or intervening elements may be present. In contrast, when an element is referred to as being "directly on," "directly connected to," "directly coupled to" or "directly contacting" another element, there are no intervening elements present. Similarly, when a first component is said to be "in electrical contact with" or "electrically coupled to" a second component, there is an electrical path between the first component and the second component that allows current to flow. The electrical path may include capacitors, coupled inductors, and/or other components that allow current to flow even without direct contact between the conductive components.

Flow charts are used herein to illustrate operations performed by systems according to embodiments of the present application. It should be understood that the preceding or following operations are not necessarily performed in the exact order in which they are performed. Rather, various steps may be processed in reverse order or simultaneously. Meanwhile, other operations are added to or removed from these processes.

According to an aspect of an embodiment of the present invention, there is provided an electric vehicle control system, as shown in fig. 1. The system comprises a vehicle control unit 1, a power motor and MCU (microcontroller)) assembly 2 and an IGBT (insulated gate bipolar transistor) 3. The vehicle control unit is also in signal connection with an accelerator pedal 4, a brake pedal 5, a gear controller 6, an instrument 7 and a front radar 8 respectively. And the power motor and MCU assembly 2 responds to the torque request of the whole vehicle controller 1 to realize the driving and feedback braking of the vehicle. The vehicle control unit 1 collects accelerator pedal information, brake pedal information and gear information of a driver, and controls enabling of a power motor and torque request according to driving requirements of the driver. The vehicle control unit 1 acquires corresponding signals generated by the brake pedal 4, the accelerator pedal 5 and the gear controller 6 through hard wires, and analyzes the brake pedal, the accelerator pedal and the gear. The vehicle control unit 1 is connected with the power motor, the MCU assembly 2 and the instrument 7 through a CAN bus.

According to another aspect of the embodiment of the invention, an energy consumption optimization method for an electric vehicle is provided, and the method is applied to the start-stop system of the electric vehicle. The vehicle control unit 1 is used for identifying the specific working condition of the vehicle and executing the energy consumption optimization step under the specific working condition. The consumption optimization step comprises but is not limited to requesting the MCU to close the IGBT through the CAN bus, and the motor has no static high-power consumption, so that the effect of reducing the energy consumption is achieved. With reference to fig. 2, 3 and 4, the specific states include a first state where the vehicle is in D range and stationary, a second state where the vehicle is in N range or P range and stationary, and a third state where the vehicle is braked at a low speed.

As shown in fig. 2, when the vehicle is in the D gear, the driver steps on the brake, and the vehicle controller monitors that the vehicle is stationary and then requests the MCU to unload the creep torque through the CAN bus and turns off the IGBT, so as to reduce the stationary energy consumption of the motor system and enter the first state. When the vehicle controller monitors that the driver releases the brake pedal, the vehicle controller requests the MCU to open the IGBT through the CAN bus, and the vehicle controller exits from the first state to prepare for starting the vehicle. When the driver depresses the accelerator pedal, the vehicle starts to run normally.

Preferably, the creep torque unloading process is that the MCU unloads the torque to 0 according to a certain gradient.

Before the energy consumption optimization step is executed in the first state, the vehicle controller optionally waits for one time, and requests the MCU to turn off the IGBT if a vehicle starting instruction is not received after the preset judgment time. The determination time is preferably 1 second to 15 seconds.

As shown in fig. 3, when the vehicle is stationary and the vehicle controller monitors that the vehicle is in the P gear or the N gear, the vehicle controller requests the MCU to turn off the IGBT through the CAN bus, and enters the second state, thereby reducing the stationary energy consumption of the motor system. And when the vehicle controller monitors that the vehicle is in the D gear or the R gear, the MCU is requested to start the IGBT through the CAN bus, and the vehicle controller exits from the second state to prepare for starting the vehicle. When the driver depresses the accelerator pedal, the vehicle starts to run normally.

As shown in fig. 4, when the driver steps on the accelerator pedal during the vehicle driving, the vehicle controller monitors that the vehicle driving speed is lower than a preset critical speed and does not receive an acceleration signal, the vehicle controller requests the MCU to turn off the IGBT through the CAN bus, optionally unloads the creep torque, and the vehicle enters a third state, and does not power to slide, thereby reducing the energy consumption of the motor. And when the vehicle controller monitors that the driver releases the brake pedal, the vehicle controller requests the MCU to restart the IGBT through the CAN bus, and the vehicle controller exits from the third state to prepare for vehicle acceleration. When the driver depresses the accelerator pedal, the vehicle starts to run with acceleration. The value of the critical speed is generally chosen to be between 5km/h and 15km/h, preferably 7 km/h.

The vehicle is optionally equipped with a front radar 8, the front radar 8 CAN detect the distance between the vehicle and a front obstacle such as a front vehicle, and in a first state, a second state or a third state, the front radar detects that the distance between the vehicle and the front obstacle becomes large, which indicates that the fleet starts to move at the moment, the vehicle may need to be started immediately, and at the moment, the vehicle control unit also requests the MCU to exit from the current first state, second state or third state through the CAN bus, so as to prepare for starting or accelerating the vehicle.

In some preferred embodiments, the meter of the vehicle is in signal communication with the vehicle control unit, and the meter displays the prompt message of "Ready" when the vehicle system is Ready for running or acceleration. When the vehicle enters the first state, the second state or the third state, the 'Ready' prompt message disappears, and when the vehicle exits the corresponding state, the 'Ready' prompt message reappears, so that the prompt message of the vehicle state is provided for the driver. In addition to the visual cues, the gauges can optionally provide audible cues to allow the driver to accurately grasp the current state of the vehicle powertrain.

It should be understood that the above-described embodiments are intended to illustrate the present invention in further detail with reference to the accompanying drawings, so that those skilled in the art can understand the technical concept of the present invention, and are not intended to limit the embodiments of the present invention. Any modification or equivalent replacement of the parts, structures or method steps involved, as well as the combination of embodiments without conflict, falls within the scope of the present claims.

Claims

1. The electric vehicle energy consumption optimization method is used for an electric vehicle control system, the electric vehicle control system comprises a vehicle control unit, a power motor, an MCU assembly and an IGBT module, and is characterized in that:

identifying a specific working condition of the vehicle by using the vehicle control unit;

executing an energy consumption optimization step under the specific working condition, wherein the energy consumption optimization step requests the MCU to close the IGBT;

the specific working condition comprises a first state that the vehicle is static and the gear is in a D gear, a second state that the vehicle is static and the gear is in an N gear or a P gear, or a third state that the vehicle brakes at a low speed.

2. The energy consumption optimization method according to claim 1, wherein in the first state, a brake pedal is pressed, and the vehicle control unit requests the MCU to unload creep torque; and when the vehicle control unit monitors that the brake pedal is released, the MCU is requested to start the IGBT so as to exit from the first state.

3. The energy consumption optimization method of claim 2, wherein the unloading creep torque process is that the MCU unloads the torque to 0 according to a gradient.

4. The energy consumption optimization method according to claim 2, wherein before the energy consumption optimization step is executed in the first state, the vehicle control unit has a determination time within which the vehicle is not started and sends a request to enter the first state.

5. The optimizable method of claim 4, wherein the decision time is 1 to 15 seconds.

6. The energy consumption optimization method according to claim 1, wherein the second state is identified when the vehicle controller monitors that the vehicle is stationary and switches to the P range or the N range, and the MCU is requested to start the IGBT and exit the second state when the vehicle controller monitors that the vehicle is in the D range or the R range.

7. The energy consumption optimization method according to claim 1, wherein when a brake pedal is pressed down during vehicle running, the vehicle controller monitors that the vehicle running speed is lower than a critical speed and does not receive an acceleration signal, and identifies the third state; and when the vehicle control unit monitors that the brake pedal is released, requesting the MCU to start the IGBT and exiting from the third state.

8. The energy consumption optimization method according to claim 7, wherein the critical speed ranges from 5 to 15 km/h.

9. The energy consumption optimization method according to any one of claims 1 to 8, wherein the electric vehicle control system further comprises a front radar for monitoring a front vehicle distance, and when the front radar monitors that the front vehicle distance is increased, the vehicle control unit is used to request the MCU to exit from the first state, the second state or the third state.

10. The energy consumption optimization method according to any one of claims 1 to 8, wherein the electric vehicle further comprises a meter, and the meter provides an image and/or sound prompt signal when the vehicle enters or exits the first state, the second state or the third state.

11. An electric vehicle control system configured to be capable of performing the energy consumption optimization method of any one of claims 1 to 10.