Electric vehicle ejection starting control method, controller and electric vehicle

Abstract

The invention provides an electric vehicle ejection starting control method, a controller and an electric vehicle. The control method is used for controlling ejection starting of the electric vehicle after the ejection starting function of the electric vehicle is started. The control method comprises the steps that at the first moment after the opening degree of the brake pedal is larger than the first brake pedal opening degree and the opening degree of the accelerator pedal is larger than the first accelerator pedal opening degree, the brake system is controlled to output braking force to wheels of the electric vehicle, and the drive motor is controlled to output torque to the wheels of the electric vehicle. And at the second moment after the first moment, the opening degree of the brake pedal is reduced to be smaller than the second brake pedal opening degree, the opening degree of the accelerator pedal is larger than the first accelerator pedal opening degree, the braking force output by the braking system is controlled to be reduced, and the torque output by the driving motor is controlled to be increased. By means of the control method, after a user starts the ejection starting function, ejection starting of the vehicle can be controlled only by operating the brake pedal and the accelerator pedal, the operation mode is simple, and the learning cost is low.

Description

Technical Field

[0001] The present application relates to the field of vehicles, and in particular to a control method for an electric vehicle, a motor controller and an electric vehicle. Background Art

[0002] With the rapid development of science and technology, the battery, motor and electronic control technology of electric vehicles have also developed rapidly, and have made great breakthroughs in terms of driving range. Therefore, people's demand for the driving pleasure and driving power control of electric vehicles is also increasing. As an important component of driving pleasure, the launch mode uses the vehicle's acceleration movement as an extension of people, providing the vehicle's heel feeling and running driving pleasure. However, the launch function of current vehicles is mostly used in fuel vehicles. How to use the launch function in electric vehicles is an urgent problem that needs to be solved. Summary of the invention

[0003] The present application provides a control method, a controller and an electric vehicle for launching a vehicle. After the user activates the launching function, the vehicle can be launched by simply operating the brake pedal and the accelerator pedal, which is simple to operate and has a low learning cost for the user.

[0004] In a first aspect, a control method for launching an electric vehicle is provided, the control method being used to control the launching of the electric vehicle after the launching function of the electric vehicle is activated. The control method comprises: at a first moment after the opening of the brake pedal is greater than the first brake pedal opening and the opening of the accelerator pedal is greater than the first accelerator pedal opening, controlling the braking system to output a braking force to the wheels of the electric vehicle and controlling the drive motor to output a torque to the wheels of the electric vehicle. And, at a second moment after the first moment, the opening of the brake pedal is reduced to less than the second brake pedal opening and the opening of the accelerator pedal is greater than the first accelerator pedal opening, controlling the braking force output by the brake system to decrease and controlling the torque output by the drive motor to increase.

[0005] The electric vehicle can be an electric vehicle or a hybrid vehicle. The electric vehicle can be a distributed drive motor or a centralized drive motor architecture, with multiple drive motors and multiple motor controllers. The drive motor can be a wheel-side motor or a wheel hub motor, and the drive motor can independently drive one wheel of the vehicle.

[0006] Electric vehicles can detect the opening of the accelerator pedal and the opening of the brake pedal through the accelerator pedal sensor and the brake pedal sensor. Taking the brake pedal sensor as an example, the brake pedal sensor is used to output a brake pedal signal, which is used to indicate the movement state of the brake pedal, so that the vehicle's control system can calculate the stroke or opening of the brake pedal according to the brake pedal signal from the brake pedal sensor and obtain the braking force requirement of the electric vehicle. Among them, the brake pedal sensor can be a brake pedal displacement sensor or a brake pedal pressure sensor. The brake pedal displacement sensor is used to monitor the movement angle of the brake pedal, and the brake pedal pressure sensor is used to monitor the pressure acting on the brake pedal. In addition, the brake pedal sensor can also be other types of sensors. Similarly, the accelerator pedal sensor can also be an accelerator pedal displacement sensor or an accelerator pedal pressure sensor.

[0007] Among them, the first brake pedal opening is a larger opening value, and the brake pedal opening is greater than the first brake pedal opening, which can be understood as the user expects the electric vehicle to remain stationary. The first accelerator pedal opening can be understood as a larger opening value, and the accelerator pedal opening is greater than the first accelerator pedal opening, which can be understood as the user expects the drive system of the electric vehicle to provide a great driving force. Exemplarily, the first brake pedal opening and the first accelerator pedal opening can be 100% opening.

[0008] At the first moment, the opening of the brake pedal is greater than the first brake pedal opening. At this time, the brake system is controlled to output braking force to the wheels of the electric vehicle to lock the wheels, so as to avoid unexpected displacement of the electric vehicle and keep the electric vehicle stationary. At the same time, since the opening of the accelerator pedal is greater than the first accelerator pedal opening, the drive motor is controlled to output torque to the vehicle of the electric vehicle, so that the drive motor can load torque when the electric vehicle is stationary, thereby providing a certain initial acceleration for the electric vehicle at the moment of starting. It is easy to understand that between the first moment and the second moment, the speed of the electric vehicle is zero.

[0009] At the second moment, the opening of the brake pedal decreases from greater than the first brake pedal opening to less than the second brake pedal opening. At this time, the brake system is controlled to reduce the output braking force, so that the electric vehicle switches from a stationary state to an accelerated starting state. At the same time, since the opening of the accelerator pedal is still greater than the first accelerator pedal opening, the drive motor is controlled to increase the torque output to the wheels of the electric vehicle, so that the acceleration of the electric vehicle after starting increases rapidly to achieve the launch start of the vehicle.

[0010] It is easy to understand that the second brake pedal opening is a smaller opening value, and the brake pedal opening being smaller than the second brake pedal opening can be understood as the user expecting the electric vehicle to start. Exemplarily, the second brake pedal opening can be 1%.

[0011] That is to say, after the launch mode is enabled, the user needs to step on the brake pedal and the accelerator pedal at the same time to control the drive motor to load torque in advance before the electric vehicle starts, and control the brake system to output braking force to keep the vehicle stationary. Afterwards, the user can control the vehicle to launch by releasing the accelerator pedal. At this time, the pre-loaded torque of the drive motor can provide great acceleration for the electric vehicle, thereby achieving launch.

[0012] According to the solution of the present application, the launch start of an electric vehicle is divided into two stages. In the first stage, the opening of the brake pedal and the accelerator pedal are both greater than the preset opening threshold. At this time, the drive motor is controlled to load the torque in advance before the electric vehicle starts, and the brake system is controlled to output the braking force so that the vehicle remains stationary. In the second stage, the opening of the brake pedal is reduced, the brake system is controlled to stop outputting the braking force to enable forward travel, and the drive system is controlled to increase the torque output so that the user can get a good acceleration experience. In this way, after the launch start function is enabled, the vehicle can be controlled by the brake pedal and the accelerator pedal to achieve a launch start. The operation is simple and intuitive, the user's learning cost is low, and it is conducive to improving the user experience.

[0013] In combination with the first aspect, in certain implementations of the first aspect, the control method further includes, after the second moment, controlling the braking force output by the braking system to be zero and controlling the torque output by the drive motor to increase to a preset value.

[0014] It can be understood that after the second moment, since the opening of the brake pedal is reduced to less than the second brake pedal opening, it is necessary to control the brake system to quickly reduce the output braking force to 0 to avoid affecting the start of the electric vehicle. In addition, the drive motor is controlled to increase the output torque value to a preset value, which can be a maximum value within the capacity of the drive motor, that is, the torque output by the drive motor is controlled to increase to the peak torque, so that the electric vehicle obtains the greatest possible acceleration, thereby improving the user experience.

[0015] According to the solution of the present application, after the electric vehicle starts, by cooperatively controlling the braking system and the drive motor, a great acceleration can be provided to the vehicle in a short time, thereby improving the user's experience of launching the vehicle.

[0016] In combination with the first aspect, in certain implementations of the first aspect, the control method further includes, before the second moment, controlling the drive motor to output the torque indicated by the torque signal. After the second moment, actively controlling the drive motor to adjust the torque output according to the resolver signal indicated by the resolver sensor.

[0017] It can be understood that before the second moment, since the electric vehicle remains stationary, the adhesion between the locked wheels and the road surface will not change, so the torque indicated by the torque signal output by the drive motor can be controlled. After the second moment, the wheels begin to rotate and the vehicle begins to accelerate. At this time, the longitudinal axle load of the vehicle will be transferred, resulting in an increase in the rear axle load of the vehicle and a decrease in the front axle load. This is manifested in the upper body pitch phenomenon of the electric vehicle at the second moment, which gives the user a sense of push back. In addition, with the change of the axle load of the whole vehicle, the adhesion of the wheels to the road surface will also change. Therefore, after the second moment, it is necessary to adjust the torque output of the drive motor in real time according to the road adhesion coefficient, while maximizing the use of the road adhesion capacity and avoiding tire burnout that affects power output and body stability.

[0018] It can be understood that when the adhesion of the wheel on the road changes, the speed and torque of the drive motor used to drive the wheel will also change. Therefore, the change in the road adhesion can be perceived by the change in the speed of the drive motor detected by the rotary sensor. The actual torque actually output by the drive motor reflects the adhesion of the road to a certain extent, so that the road adhesion can be accurately and quickly observed in real time according to the rotary signal and the torque signal. Specifically, the rotation speed of the drive motor can be obtained by the rotary signal of the rotary sensor, and the angular velocity of the wheel can be calculated by the rotation speed of the drive motor and the transmission ratio of the electric vehicle. The slip rate of each wheel can be obtained by combining the wheel radius and the speed of the electric vehicle, and then the adhesion of the road is observed in real time according to the slip rate of the wheel. It is easy to understand that the road adhesion observation in this application can be realized based on the rotary signal, without the need to collect the vehicle speed and wheel speed at the same time, and the observation delay is lower and the accuracy is higher. In addition, the torque closed-loop regulation in this application can be realized in a closed loop inside the motor controller, without the need for coordinated control by the electronic body stability system (Electronic Stability Control, ESC)-vehicle controller-motor controller, which is conducive to shortening the communication link to shorten the control delay.

[0019] According to the embodiment of the present application, by observing the road adhesion in real time and adjusting the torque output by the drive motor to keep the wheel slip rate in a stable range, it is possible to avoid tire burnout and affect power output and vehicle stability. In addition, the observation of road adhesion and the adjustment of the output torque of the drive motor in the present application are both implemented inside the drive system, with a shorter time delay, and can almost achieve microsecond (us)-level rapid observation and millisecond (ms)-level torque adjustment.

[0020] In combination with the first aspect, in certain implementations of the first aspect, the control method specifically includes, after the second moment, actively controlling the drive motor to adjust the torque output according to the resolver signal indicated by the resolver sensor so that the torque value output by the drive motor is not equal to the torque value indicated by the torque signal.

[0021] It can be understood that after the second moment, the electric vehicle starts to launch, and the torque output can be adjusted by directly controlling the drive motor through the motor controller, rather than controlling the drive motor to adjust the torque output in response to the indication of the torque signal. Therefore, since the operation of the motor controller and the drive motor is decoupled from the vehicle controller, the torque output of the drive motor will be different from the torque value indicated by the torque signal. At this time, the vehicle controller actually no longer controls the torque of the motor controller and the drive motor, and the torque output of the drive motor is different from the torque value indicated by the torque signal. Exemplarily, after the second moment, the torque output of the drive motor may be less than the torque value indicated by the torque signal.

[0022] In combination with the first aspect, in certain implementations of the first aspect, the control method specifically includes actively controlling the drive motor to reduce torque output when, after the second moment, the speed increase value of the drive motor within the preset time period indicated by the rotary signal is greater than a preset speed change value.

[0023] It is understandable that after the electric vehicle is launched, when the wheels move from a high-adhesion road surface (such as a dry paved road surface) to a low-adhesion road surface (such as a wet road surface, an icy road surface), since the torque required by the low-adhesion road surface is small, if the drive motor still outputs the torque value indicated by the torque signal, the driving force on the wheel will exceed the road adhesion limit, causing the wheel slip rate to increase, thereby driving the drive motor to abnormally increase the speed, causing the drive motor to increase within a preset time to be greater than the preset speed. In this scenario, it is necessary to control the drive motor to reduce the torque output based on the torque value indicated by the torque signal, so that the driving force on the wheel matches the road adhesion capacity of the low-adhesion road surface, maximizing the use of the road adhesion capacity.

[0024] According to the solution of the present application, after the electric vehicle is launched, the drive motor is actively controlled to adjust the torque output according to the resolver signal, which can shorten the signal transmission link and further improve the control accuracy and immediacy.

[0025] In combination with the first aspect, in certain implementations of the first aspect, the control method further includes, after the second moment, actively controlling the drive motor to adjust the torque output according to the resolver signal indicated by the resolver sensor, while controlling another drive motor coaxial with the drive motor to adjust the torque output so that the torques output by the drive motor and the other drive motor are equal.

[0026] It is understandable that after the electric vehicle is launched, the wheels on both sides may contact roads with different adhesion capabilities. For example, when one wheel passes through a road with accumulated water, if only the drive motor is controlled to adjust the torque output, the two coaxial wheels will be subjected to unequal driving forces, which will cause the force balance of the entire vehicle to be destroyed, making it difficult to maintain the vehicle's straight-line driving, affecting the user experience and even causing potential safety hazards. In response to this scenario, the present application proposes to actively adjust the torque output of one drive motor according to the resolver signal while adjusting the torque output of the other coaxial drive motor to ensure that the driving forces on both wheels are equal, so that the vehicle can maintain straight-line driving after starting.

[0027] According to the embodiment of the present application, for an electric vehicle with a distributed power architecture, controlling the torque output by two coaxial drive motors to maintain a dynamic balance is beneficial to improving the safety and reliability of the launch function.

[0028] In combination with the first aspect, in certain implementations of the first aspect, the control method further includes controlling the torque value indicated by the torque signal to be a first preset value between the first moment and the second moment. After the second moment, controlling the torque value indicated by the torque signal to be a second preset value greater than the first preset value.

[0029] That is to say, even if the opening of the accelerator pedal remains unchanged after the first moment, the control method provided in the embodiment of the present application changes the torque value indicated by the torque signal after the second moment. Specifically, between the first moment and the second moment, the vehicle needs to be kept stationary while loading the torque. In order to avoid excessive burden on the braking system, the drive motor can be controlled by the torque signal to output a smaller first torque value. After the second moment, it is necessary to control the drive motor to quickly output the peak torque. Therefore, the drive motor can be controlled by the torque signal to output a larger second torque value, so that the speed of the electric vehicle can be quickly increased.

[0030] It is understood that the embodiment of the present application does not limit the specific value of the first preset value. Exemplarily, the first preset value may be 50% of the second preset value.

[0031] According to the solution of the present application, at different stages of the launch start of the electric vehicle, the torque signal is actively controlled to indicate different torque values. A certain torque value can be loaded before the vehicle starts, and the peak torque can be quickly output after the vehicle starts, thereby ensuring the stability of the launch start while providing the user with a better acceleration experience.

[0032] In combination with the first aspect, in certain implementations of the first aspect, the control method specifically includes: at a third moment after the second moment, controlling the torque output by the drive motor to increase from the first preset value to the second preset value. At a fourth moment after the third moment, the speed increase value of the drive motor within the preset time length indicated by the resolver signal is greater than the preset speed change value, and controlling the torque output by the drive motor to decrease to the first torque value.

[0033] Specifically, between the second moment and the third moment, the drive motor is first controlled to increase from the first preset value to the second preset value according to the instruction of the torque signal, so as to bring greater acceleration to the electric vehicle. Between the third moment and the fourth moment, the road adhesion is observed according to the resolver signal, and the torque output by the drive motor is reduced to the first torque value according to the road adhesion. The first torque value can be understood as the maximum torque value matching the road load.

[0034] It can be understood that if after the third moment, the speed increases or decreases to a value less than the preset change value within the preset time period indicated by the resolver signal, the torque output by the control drive motor is maintained at the second preset value.

[0035] According to the embodiment of the present application, it is proposed to observe the road adhesion in real time through the resolver signal, and when the driving force corresponding to the torque signal is greater than the road adhesion capacity, the drive motor is actively controlled to adjust the output torque based on the road adhesion. In this way, since the torque output by the drive motor matches the road adhesion, there is no need to perform torque recovery, and the wheels will not slip again, thereby reducing the torque fluctuation output by the drive motor and improving the driving experience.

[0036] In combination with the first aspect, in certain implementations of the first aspect, the control method further includes, between the first moment and the second moment, controlling the braking force output by the braking system to increase as the torque output by the drive motor increases.

[0037] It can be understood that before the first moment, the drive motor has not yet outputted a driving force to the wheel of the electric vehicle, and at this time the braking system can output a smaller first braking force to the wheel of the electric vehicle to lock the wheel. At the first moment, since the drive motor begins to output torque to achieve torque preloading, the braking system needs to increase the braking force output to the second braking force to keep the wheel of the electric vehicle locked. Between the first moment and the second moment, since the torque output by the drive motor continues to increase, the braking system also needs to increase the output second braking force to keep the wheel of the electric vehicle locked.

[0038] According to the embodiment of the present application, before the electric vehicle starts to start, the braking system will continuously output braking force to keep the speed of the electric vehicle locked, thereby preventing the electric vehicle from moving unexpectedly to improve the reliability and stability of the electric vehicle's launch start. In addition, the braking system can dynamically increase the braking force output following the driving force output by the driving motor, without the need to continuously output a large braking force, which is beneficial to reducing the energy consumption of the electric vehicle.

[0039] In combination with the first aspect, in certain implementations of the first aspect, the control method further includes controlling the central control screen to display a torque loading mark between the first moment and the second moment and controlling the torque loading mark to change with the torque output by the drive motor. And, at the second moment, controlling the central control screen to stop displaying the torque loading mark and displaying a launch start mark.

[0040] It can be understood that as a driving mode that provides driving pleasure for users, human-computer interaction is also a very important part of the user experience in the launch mode. In an embodiment of the present application, after the user enables the launch mode before the first moment, the central control screen of the electric vehicle will prompt the user that the launch mode has been activated and display the torque loading mark unique to the launch mode. Between the first moment and the second moment, the torque loading mark in the central control screen is controlled to change with the torque output of the drive motor, so that the user can determine the torque output of the drive motor through the torque loading mark. At the second moment, the central control screen is controlled to stop displaying the torque loading mark and display the launch start mark, so that the user can experience the launch start with the launch start mark, and realize a multi-dimensional experience of vision and feeling.

[0041] It is to be understood that the embodiments of the present application do not limit the specific form of the torque loading mark. Exemplarily, the torque loading mark can be a circular ring-shaped mark, the diameter of which increases as the torque output of the drive motor increases, and stops increasing after the torque output of the drive motor reaches a preset torque value, thereby presenting a diffuse visual effect. Exemplarily, the torque loading mark can also be a bar-shaped mark, the length of which increases as the torque output of the drive motor increases, and stops increasing after the torque output of the drive motor reaches a preset torque value, thereby presenting a progress bar loading visual effect.

[0042] It can be understood that the control method provided by the present application can not only control the display of the above torque loading logo and the ejection start logo in the central control screen of the electric vehicle, but also control other screens of the electric vehicle, such as the main driver's instrument screen or the co-driver's screen or the head-up display system (Head Up Display, HUD) to display the above two logos. In addition, the color and flashing frequency of the atmosphere light of the electric vehicle can also be controlled to change with the torque output by the drive motor. In this way, the user's visual experience can be further improved, and the atmosphere can be stronger.

[0043] According to an embodiment of the present application, a torque loading mark and a launch start mark are displayed on the central control screen of the electric vehicle, and the torque loading mark changes dynamically with the torque output by the drive motor, so that the user can get a stronger visual impact while confirming the current torque output of the drive motor, thereby further improving the user experience.

[0044] In combination with the first aspect, in certain implementations of the first aspect, the control method specifically includes controlling the launch control function to be turned off after the second moment, when the speed of the electric vehicle is greater than the preset speed, the opening of the brake pedal increases from zero to a second brake pedal opening, or the opening of the accelerator pedal of the electric vehicle decreases to less than the first accelerator pedal opening.

[0045] It can be understood that the preset vehicle speed is a relatively high vehicle speed. After the electric vehicle accelerates to the preset vehicle speed after the launch start, the launch process of the electric vehicle can be completed. At this time, the launch start function can be controlled to be turned off. The second brake pedal opening is a relatively small opening value. During the launch start process, if the brake pedal opening increases from zero to the second brake pedal opening, or if the accelerator pedal opening of the electric vehicle decreases to less than the first accelerator pedal opening during the launch start process, it can be understood that the user expects the vehicle to stop accelerating. In this way, in order to meet user expectations, the control method provided in the embodiment of the present application will control the launch start function of the electric vehicle to be turned off.

[0046] It is understandable that after the launch function is turned off, if the user expects to perform the next launch function, the launch function needs to be enabled again according to the above method.

[0047] According to an embodiment of the present application, during the launch-start process of an electric vehicle, when the vehicle speed reaches a preset speed or the user actively steps on the brake pedal or actively releases the accelerator pedal, the launch-start function is controlled to be turned off. The flexibility of turning off the launch-start function is high, and the safety and reliability of the launch-start function of the electric vehicle are stronger.

[0048] In a second aspect, the present application provides a vehicle controller for executing the control method as described in the first aspect and its various implementations.

[0049] The vehicle controller in the present application may be a motor controller of an electric vehicle, or a whole vehicle controller, or a separately set controller with control capability. The vehicle controller is applicable to an electric vehicle or a hybrid vehicle, and the electric vehicle may be a distributed motor or a centralized motor architecture, with multiple drive motors and multiple motor controllers, and the vehicle controller may be any one of the multiple motor controllers.

[0050] In a third aspect, the present application provides an electric vehicle, which includes a vehicle controller, a braking system, and a drive system as described in the second aspect. The drive system includes a motor controller and a drive motor, and the motor controller is used to control the drive motor to output a driving torque to the wheels of the electric vehicle. The braking system is used to output braking force to the four wheels.

[0051] The beneficial effects of the second and third aspects mentioned above can refer to the beneficial effects described in the first aspect, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 is a schematic diagram of an electric vehicle provided in an embodiment of the present application;

[0053] Figure 2 is a schematic diagram of the architecture of an electric vehicle provided in an embodiment of the present application;

[0054] Figure 3 is a timing diagram of the launch control process of an electric vehicle provided in an embodiment of the present application;

[0055] Figure 4 It is a schematic diagram of a scenario of a launch start of an electric vehicle provided in an embodiment of the present application;

[0056] Figure 5 is a schematic diagram of a user interface of an electric vehicle provided in an embodiment of the present application;

[0057] Figure 6 This is a schematic diagram of a vehicle controller architecture provided by an embodiment of the present application;

[0058] Figure 7 It is a flow chart of the launch control of the vehicle controller provided in the embodiment of the present application. DETAILED DESCRIPTION

[0059] The technical solution in this application will be described below in conjunction with the accompanying drawings.

[0060] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or. For example, A / B can mean A or B. The “and / or” in this article is merely a way to describe the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone.

[0061] In the embodiments of the present application, prefixes such as "first" and "second" are used only to distinguish different description objects, and have no limiting effect on the position, order, priority, quantity or content of the described objects. The use of prefixes such as ordinal numbers to distinguish description objects in the embodiments of the present application does not constitute a limitation on the described objects. For the statement of the described objects, please refer to the description in the context of the claims or embodiments, and no unnecessary limitation should be constituted due to the use of such prefixes. In addition, in the description of the present embodiment, unless otherwise specified, the meaning of "multiple" is two or more.

[0062] References to "some embodiments" and the like described in this specification mean that a particular feature, structure or characteristic described in conjunction with the embodiment is included in one or more embodiments of the present application. Thus, phrases such as "in some embodiments" and the like that appear at different places in this specification do not necessarily all refer to the same embodiment, but rather mean "one or more but not all embodiments", unless otherwise specifically emphasized. The terms "include", "comprises", "has" and their variations all mean "including but not limited to", unless otherwise specifically emphasized.

[0063] With the rapid development of science and technology, the battery, motor and electronic control technology of electric vehicles have also developed rapidly, and have made great breakthroughs in terms of driving range. After alleviating the anxiety about driving range, people's demand for the driving pleasure and driving power controllability of electric vehicles has also increased. As an important component of driving pleasure, the launch mode regards the acceleration movement of the vehicle as an extension of people, providing the vehicle's heel feel and running driving pleasure. Specifically, launch start, as a fast starting method for a car, can obtain a large acceleration at the beginning of the car, achieve a fast start, and make the car have better acceleration performance at the start. However, the launch start function of current vehicles is mostly used in traditional energy vehicles. How to use the launch start function in electric vehicles is a problem that needs to be solved urgently.

[0064] In view of this, the embodiments of the present application provide a control method, a controller and an electric vehicle for launching a vehicle. After the user enables the launching function, the vehicle can be launched by simply operating the brake pedal and the accelerator pedal, which is simple to operate and has a low learning cost for the user.

[0065] Figure 1 and Figure 2 It is a schematic diagram of the architecture of the electric vehicle 10 provided in an embodiment of the present application.

[0066] like Figure 1As shown, the electric vehicle 10 includes a vehicle controller 20, a drive system, a brake system 60, a power battery (not shown) and a plurality of wheels. The drive system includes a drive motor 30 and a motor controller 40. The motor controller 40 is used to output current to the drive motor 30 to control the drive motor 30 to output torque to drive the electric vehicle 10.

[0067] The vehicle controller in the present application may be the motor controller 40 of the electric vehicle 10, or the vehicle controller 20, or a separately provided controller with control capabilities, without limitation.

[0068] It is understandable that the electric vehicle 10 in the embodiment of the present application can be any one of different types of vehicles such as a car, a truck, a passenger bus, etc., and can also be a transport device for carrying people or goods such as a tricycle or a two-wheeled vehicle, or other types of vehicles driven by power batteries, which are not limited in the embodiment of the present application. Among them, the vehicle includes but is not limited to a pure electric vehicle (pure electric vehicle / battery electric vehicle, pure EV / batteryEV), a hybrid electric vehicle (hybrid electric vehicle, HEV), a range extended electric vehicle (range extended electric vehicle, REEV), a plug-in hybrid electric vehicle (plug-in hybrid electric vehicle, PHEV), etc.

[0069] The power battery in the embodiment of the present application can be a lithium-ion battery, a lithium metal battery, a lead-acid battery, a nickel-cadmium battery, a nickel-hydrogen battery, a lithium-sulfur battery, a lithium-air battery or a sodium-ion battery, etc., which is not limited in the present application. The power battery can also power other electrical devices in the vehicle, such as the air conditioner in the vehicle, the car player, etc.

[0070] The electric vehicle 10 can be a rear-wheel drive vehicle, with the two rear wheels driven by a drive motor 30. The electric vehicle 10 can also be a distributed four-drive motor drive architecture, with the drive motors arranged on the sides of the driven wheels and controlled by a separate motor controller 40. The electric vehicle 10 can also be a centralized drive motor drive architecture, with the drive motors for driving the two front wheels or the two rear wheels arranged together. The motor controller 40 can be one or more. The motor controller 40 and the drive motor 30 can correspond one to one, or one motor controller 40 can correspond to multiple drive motors 30. The motor controller 40 is used to control one or more drive motors 30 to output torque to drive the electric vehicle 10.

[0071] In one embodiment, if Figure 2As shown in (a) of FIG. 1 , the electric vehicle 10 may be a distributed four-drive motor drive architecture, where the drive motors are arranged on the sides of the driven wheels and controlled by separate motor controllers. The electric vehicle 10 may also be a Figure 2 The centralized four-drive motor drive architecture shown in (b) is configured such that two drive motors for driving two front wheels or two rear wheels are arranged together.

[0072] Exemplarily, the electric vehicle 10 includes four motor controllers, including a motor controller 41, a motor controller 42, a motor controller 43, and a motor controller 44. The four motors include a drive motor 31, a drive motor 31, a drive motor 33, and a drive motor 34. The motor controller 41 controls the drive motor 31 to drive the wheel 51, the motor controller 42 controls the drive motor 32 to drive the wheel 52, the motor controller 43 controls the drive motor 33 to drive the wheel 53, and the motor controller 44 controls the drive motor 34 to drive the wheel 54.

[0073] In one embodiment, the electric vehicle 10 may also be Figure 2 The centralized drive motor architecture shown in (c) uses one drive motor to drive the two front wheels of the electric vehicle 10, and uses two drive motors to drive the two rear wheels of the electric vehicle 10 respectively.

[0074] In one embodiment, the various architectures mentioned above may be combined, for example, the front drive adopts a distributed drive motor architecture and the rear drive adopts a centralized drive motor architecture.

[0075] The vehicle controller provided in the present application may be any motor controller among a plurality of motor controllers.

[0076] The electric vehicle 10 further includes an accelerator pedal, a brake pedal, a steering system and a steering wheel. The accelerator pedal is used to indicate the torque output to the wheels of the electric vehicle 10. The brake pedal is used to indicate the braking force output to the wheels of the electric vehicle 10, the steering angle of the steering wheel is used to indicate the steering angle of the two front wheels, and the steering system is used to control the steering angle of the two front wheels of the electric vehicle 10.

[0077] In one embodiment, the brake system 60 includes a brake controller and a plurality of wheel-end brake devices, and the brake controller is connected to the brake pedal signal. The brake controller can be used to determine the braking force according to the opening of the brake pedal. During the driving process, when the electric vehicle 10 needs to brake, the driver steps on the brake pedal, the brake controller receives the brake pedal signal from the brake pedal and outputs a braking force distribution signal to the wheel-end brake device, and the wheel-end brake device is used to receive the braking force distribution signal and output a clamping force to the brake disc according to the instruction of the braking force distribution signal, thereby generating a friction braking force, so that the electric vehicle 10 is braked.

[0078] In one embodiment, the motor controller 40 includes a signal interface, and the motor controller 40 is connected to the vehicle controller 20 and other motor controllers 40 through the signal interface. The vehicle controller 20 is connected to the accelerator pedal signal, and the vehicle controller 20 calculates the vehicle torque demand according to the opening of the accelerator pedal during the driving process of the electric vehicle 10, and sends a torque signal to the motor controller 40 according to the vehicle torque demand. Each motor controller 40 controls the corresponding drive motor to output torque to drive the corresponding wheel according to the indication of the torque signal.

[0079] In one embodiment, each motor controller 40 may also be directly connected to an accelerator pedal, and control the corresponding motor output torque according to a torque signal output by the accelerator pedal.

[0080] In one embodiment, the vehicle controller 20 is connected to the brake pedal through a signal interface. The vehicle controller 20 calculates the vehicle braking demand based on the brake pedal opening of the electric vehicle 10 during driving and sends a braking signal to the brake controller based on the vehicle braking demand. The brake controller controls the corresponding wheel-end braking device to output braking force to brake the corresponding wheel according to the indication of the braking signal.

[0081] In one embodiment, the vehicle controller 20 may also be directly connected to the brake pedal, and control the wheel-end brake device to output the braking force according to the opening of the brake pedal.

[0082] In one embodiment, each motor controller 40 uses a resolver sensor through a signal interface, and the resolver sensor is used to detect the speed of the drive motor 30 controlled by the motor controller 40, and the motor controller 40 is used to receive the signal from the resolver sensor. The motor controller 40 can also generate a speed signal according to the signal from the resolver sensor and send the speed signal to the other three motor controllers 40. Similarly, each motor controller 40 will also receive the speed signal sent by the other three motor controllers 40.

[0083] The resolver sensor can accurately detect the position, direction and speed of the motor rotor, and is responsible for monitoring and extracting the rotation speed of the drive motor. It has a high sampling rate and is directly connected to the motor controller 40, with short signal transmission time and higher stability.

[0084] In one embodiment, the motor controller 40 also obtains vehicle signals from the vehicle controller 20 or other sensors of the electric vehicle 10 through a signal interface, and the vehicle signals are used to indicate the speed, yaw rate, center of mass sideslip angle, etc. of the electric vehicle 10.

[0085] In one embodiment, the motor controller 40 can be connected to the vehicle controller 20 and the steering system through a controller area network (CAN) bus, a local interconnect network (LIN) bus, a high-speed fault-tolerant network protocol (FlexRay) or other types of connection methods, and interact with signals.

[0086] In one embodiment, the electric vehicle 10 includes a launch start button. The launch start button is used to start a launch start mode, which is used to control the driving system and braking system of the electric vehicle during the start process of the electric vehicle 10 to launch the electric vehicle 10.

[0087] The electric vehicle 10 may be provided with a launch start button for the driver to operate. Exemplarily, the launch start button may be a physical button, and the driver may start the launch start mode of the electric vehicle 10 by pressing the physical button, so that the launch start control is started when the electric vehicle 10 is starting. Exemplarily, the launch start button may be a virtual button on the central control screen, and the driver may start the launch start mode of the electric vehicle 10 by selecting the launch start mode.

[0088] It can be understood that the vehicle controller provided in the present application can be a vehicle controller 20, a motor controller 40, or other separately set controller with control capabilities.

[0089] The architecture of the embodiment of the present application is introduced above. The control method provided by the embodiment of the present application is described in detail below in conjunction with a specific embodiment.

[0090] The control method for launching a launch vehicle provided in the embodiment of the present application is used to control the braking system to output braking force and the driving system to output driving force according to the opening of the accelerator pedal and the opening of the brake pedal during the launch of the electric vehicle 10, and then control the braking system to stop outputting the braking force, so that the speed of the electric vehicle can be quickly increased after the user releases the brake pedal, thereby achieving the launch effect. Figure 3 and Figure 4 The launch control method and vehicle controller provided by the embodiment of the present application are described at the first moment t1, the second moment t2, the third moment t3 and the fourth moment t4 during the starting process of the electric vehicle 10. Figure 3 is a signal timing diagram of the electric vehicle 10 during driving, Figure 3 This includes the relationship between the speed of the electric vehicle, the opening of the accelerator pedal, the opening of the brake pedal, the braking force, the driving torque output by the driving motor, and the torque indicated by the torque command during the driving of the electric vehicle.

[0091] In one embodiment, before the first moment t1, the user controls the electric vehicle to start a launch start mode by touching the central control screen of the electric vehicle 10 or activating a launch start button. The launch start mode is used to control the drive system and braking system of the electric vehicle 10 during the starting process of the electric vehicle 10 to enable the electric vehicle to launch start.

[0092] It can be understood that the launch start can be used as an optional operating mode of the electric vehicle 10. Only when the user has previously activated the launch start mode will the launch start control be performed during the starting process.

[0093] It is understandable that the user can turn on the launch mode in the parking gear (i.e., P gear), or step on the brake in neutral gear (i.e., N gear) or drive gear (i.e., D gear) and turn on the launch mode. This embodiment of the present application is not limited to this.

[0094] In one embodiment, after the launch mode is activated, the control method provided in the embodiment of the present application includes detecting the opening of the accelerator pedal and the opening of the brake pedal during the starting process of the electric vehicle 10 .

[0095] Exemplarily, the electric vehicle 10 can detect the opening of the accelerator pedal and the opening of the brake pedal through an accelerator pedal sensor and a brake pedal sensor. Taking the brake pedal sensor as an example, the brake pedal sensor is used to output a brake pedal signal, which is used to indicate the movement state of the brake pedal, so that the vehicle's control system can calculate the stroke or opening of the brake pedal according to the brake pedal signal from the brake pedal sensor and then obtain the braking force requirement of the electric vehicle 10. Among them, the brake pedal sensor can be a brake pedal displacement sensor or a brake pedal pressure sensor. The brake pedal displacement sensor is used to monitor the movement angle of the brake pedal, and the brake pedal pressure sensor is used to monitor the pressure acting on the brake pedal. In addition, the brake pedal sensor can also be other types of sensors. Similarly, the accelerator pedal sensor can also be an accelerator pedal displacement sensor or an accelerator pedal pressure sensor.

[0096] like Figure 3 and Figure 4 As shown, in one embodiment, at a first moment t1 after the opening of the brake pedal is greater than the first brake pedal opening and the opening of the accelerator pedal is greater than the first accelerator pedal opening, the brake system 60 is controlled to output a braking force to the wheels of the electric vehicle 10 and the drive motor 30 is controlled to output a torque to the wheels of the electric vehicle 10. At a second moment t2 after the first moment t1, the opening of the brake pedal decreases to less than the second brake pedal opening and the opening of the accelerator pedal is greater than the first accelerator pedal opening, the braking force output by the brake system 60 is controlled to decrease and the torque output by the drive motor 30 is controlled to increase.

[0097] Among them, the first brake pedal opening is a larger opening value, and the brake pedal opening is greater than the first brake pedal opening, which can be understood as the user expects the electric vehicle to remain stationary. The first accelerator pedal opening can be understood as a larger opening value, and the accelerator pedal opening is greater than the first accelerator pedal opening, which can be understood as the user expects the drive system of the electric vehicle to provide a great driving force. Exemplarily, the first brake pedal opening and the first accelerator pedal opening can be 100% opening.

[0098] At the first moment t1, the opening of the brake pedal is greater than the first brake pedal opening. At this time, the brake system 60 is controlled to output braking force to the wheels of the electric vehicle 10 to lock the wheels, so as to avoid unexpected displacement of the electric vehicle 10, so that the electric vehicle 10 remains stationary. At the same time, since the opening of the accelerator pedal is greater than the first accelerator pedal opening, the drive motor 30 is controlled to output torque to the vehicle of the electric vehicle 10, so that the drive motor 30 can load torque when the electric vehicle 10 is stationary, thereby providing a certain initial acceleration for the electric vehicle 10 at the moment of starting. It is easy to understand that between the first moment t1 and the second moment t2, the speed of the electric vehicle 10 is zero.

[0099] At the second moment t2, the opening of the brake pedal decreases from greater than the first brake pedal opening to less than the second brake pedal opening. At this time, the brake system 60 is controlled to reduce the output braking force, so that the electric vehicle 10 switches from a stationary state to an accelerated start state. At the same time, since the opening of the accelerator pedal is still greater than the first accelerator pedal opening, the drive motor 30 is controlled to increase the torque output to the wheels of the electric vehicle 10, so that the acceleration of the electric vehicle 10 increases rapidly after starting, so as to achieve the launch start of the vehicle.

[0100] It is easy to understand that the second brake pedal opening is a smaller opening value, and the brake pedal opening being smaller than the second brake pedal opening can be understood as the user expecting the electric vehicle to start. Exemplarily, the second brake pedal opening can be 1%.

[0101] According to an embodiment of the present application, the launch control of an electric vehicle is divided into two stages. In the first stage, the opening of the brake pedal and the accelerator pedal are both greater than the preset opening threshold. At this time, the drive motor is controlled to load the torque in advance before the electric vehicle starts, and the brake system is controlled to output the braking force so that the vehicle remains stationary. In the second stage, the opening of the brake pedal is reduced, the brake system is controlled to stop outputting the braking force to enable forward travel, and the drive system is controlled to increase the torque output so that the user can obtain a good acceleration experience. In this way, after the launch control function is enabled, the vehicle can be controlled by the brake pedal and the accelerator pedal to achieve a launch control. The operation is simple and intuitive, the user's learning cost is low, and it is conducive to improving the user experience.

[0102] Continue to refer Figure 3In some embodiments, between the first moment t1 and the second moment t2, the torque value indicated by the control torque signal is a first preset value. After the second moment t2, the torque value indicated by the control torque signal is a second preset value greater than the first preset value.

[0103] That is to say, even if the opening of the accelerator pedal remains unchanged after the first moment t1, the control method provided in the embodiment of the present application changes the torque value indicated by the torque signal after the second moment t2. Specifically, between the first moment t1 and the second moment t2, during this period, the vehicle needs to be kept stationary while loading the torque. In order to avoid excessive burden on the braking system 60, the drive motor 30 can be controlled by the torque signal to output a smaller first preset value. After the second moment t2, it is necessary to control the drive motor 30 to quickly output the peak torque. Therefore, the drive motor 30 can be controlled by the torque signal to output a larger second preset value, so that the speed of the electric vehicle 10 can be quickly increased.

[0104] It is understood that the embodiment of the present application does not limit the specific value of the first torque value. Exemplarily, the first torque value may be 50% of the second torque value.

[0105] According to an embodiment of the present application, at different stages of the launch start of an electric vehicle, the torque signal is actively controlled to indicate different torque values, so that a certain torque value can be loaded before the vehicle starts, and the peak torque can be quickly output after the vehicle starts, thereby ensuring the stability of the launch start while providing users with a better acceleration experience.

[0106] In some embodiments, between the first time t1 and the second time t2, the central control screen is controlled to display the torque loading mark and the torque loading mark is controlled to change with the torque output by the drive motor 30. At the second time t2, the central control screen is controlled to stop displaying the torque loading mark and display the launch start mark.

[0107] It can be understood that the launch mode is a driving mode that provides driving pleasure to the user, and human-computer interaction is also an important part of the user experience. In the embodiment of the present application, after the user activates the launch mode before the first moment t1, the central control screen of the electric vehicle 10 will prompt the user that the launch mode has been activated and display the torque loading mark unique to the launch mode. Figure 5 In (a) or (b), between the first moment t1 and the second moment t2, the torque loading mark in the control center screen changes with the torque output by the drive motor 30, so that the user can determine the torque output of the drive motor 30 through the torque loading mark. Figure 5 In (c), at the second moment t2, the central control screen is controlled to stop displaying the torque loading logo and display the launch start logo, so that the user can experience the launch start with the launch start logo, achieving a multi-dimensional experience of vision and feeling.

[0108] It is understood that the specific form of the torque loading mark is not limited in the embodiment of the present application. Figure 5 As shown in (a) of FIG. 1 , the torque loading mark may be a circular mark, the diameter of which increases as the torque output by the drive motor 30 increases, and stops increasing after the torque output by the drive motor 30 reaches a preset torque value, thereby presenting a diffuse visual effect. For example, Figure 5 As shown in (b), the torque loading mark can also be a bar mark, the length of which increases as the torque output by the drive motor 30 increases, and stops increasing after the torque output by the drive motor 30 reaches a preset torque value, thereby presenting a visual effect of a progress bar loading.

[0109] It can be understood that the condition for controlling the central control screen to stop displaying the torque loading mark and displaying the launch start mark can be that the torque output by the drive motor 30 reaches the first preset value, and it can be understood that the drive motor 30 has completed the torque preloading, so the launch start mark can be displayed to prompt the user to release the brake pedal to achieve the launch start. Alternatively, the condition for controlling the central control screen to stop displaying the torque loading mark and displaying the launch start mark can also be that the opening of the brake pedal is reduced to less than the second brake pedal opening. At this time, even if the torque output by the drive motor 30 can continue to increase, it is necessary to control the central control screen to display the launch start mark to improve the user's visual experience.

[0110] It can be understood that the control method provided in the present application can not only control the display of the torque loading mark and the launch start mark in the central control screen of the electric vehicle 10, but also control other screens of the electric vehicle 10, such as the main driver's instrument screen or the co-driver's screen or the head-up display system (Head Up Display, HUD) to display the above two marks. In addition, the color and flashing frequency of the atmosphere light of the electric vehicle 10 can also be controlled to change with the torque output by the drive motor 30. In this way, the user's visual experience can be further improved, and the atmosphere can be stronger.

[0111] According to an embodiment of the present application, a torque loading mark and a launch start mark are displayed on the central control screen of the electric vehicle, and the torque loading mark changes dynamically with the torque output by the drive motor, so that the user can get a stronger visual impact while confirming the current torque output of the drive motor, thereby further improving the user experience.

[0112] In some embodiments, between the first time t1 and the second time t2 , the braking force output by the control braking system 60 increases as the torque output by the driving motor 30 increases.

[0113] like Figure 3As shown, before the first moment t1, the drive motor 30 has not yet outputted a driving force to the wheels of the electric vehicle 10, and at this time the brake system 60 can output a small first braking force to the wheels of the electric vehicle 10 to lock the wheels. At the first moment t1, since the drive motor 30 begins to output torque to achieve torque preloading, the brake system 60 needs to increase the braking force output to the second braking force to keep the wheels of the electric vehicle 10 locked. Between the first moment t1 and the second moment t2, since the torque output by the drive motor 30 continues to increase, the brake system 60 also needs to increase the output second braking force to keep the wheels of the electric vehicle 10 locked.

[0114] According to the embodiment of the present application, before the electric vehicle starts to start, the braking system will continuously output braking force to keep the speed of the electric vehicle locked, thereby preventing the electric vehicle from moving unexpectedly to improve the reliability and stability of the electric vehicle's launch start. In addition, the braking system can dynamically increase the braking force output following the driving force output by the driving motor, without the need to continuously output a large braking force, which is beneficial to reducing the energy consumption of the electric vehicle.

[0115] In some embodiments, after the second time t2, the braking force output by the braking system 60 is controlled to be zero and the torque output by the driving motor 30 is controlled to increase to a preset value.

[0116] like Figure 3 As shown, after the second moment t2, since the opening of the brake pedal is reduced to less than the second brake pedal opening, it is necessary to control the brake system 60 to quickly reduce the output braking force to 0 to avoid affecting the start of the electric vehicle 10. In addition, the drive motor 30 is controlled to increase the output torque value to a preset value, which can be a maximum value within the capacity of the drive motor 30, that is, the torque output by the drive motor 30 is controlled to increase to the peak torque, so that the electric vehicle 10 obtains the maximum acceleration, thereby improving the user experience.

[0117] According to the embodiment of the present application, after the electric vehicle starts, by cooperatively controlling the braking system and the drive motor, a great acceleration can be provided to the vehicle in a short period of time, thereby improving the user's experience of launching the vehicle.

[0118] In some embodiments, before the second time t2, the drive motor 30 is controlled to output the torque indicated by the torque signal. After the second time t2, the drive motor 30 is actively controlled to adjust the torque output according to the resolver signal indicated by the resolver sensor.

[0119] It can be understood that before the second moment t2, since the electric vehicle 10 remains stationary, the adhesion between the locked wheels and the road surface will not change, so the drive motor 30 can be controlled to output the torque indicated by the torque signal. After the second moment t2, the wheels start to rotate and the vehicle starts to accelerate. At this time, the longitudinal axle load of the vehicle will be transferred, resulting in an increase in the rear axle load of the vehicle and a decrease in the front axle load, which is manifested as Figure 4 At the second moment t2 in the figure, the electric vehicle 10 has a similar situation that the front of the vehicle is lifted and the rear of the vehicle is sunk, that is, the upper vehicle body pitches, which brings a push-back feeling to the user. In addition, in order to maintain stable power output, the torque output of the drive motor 30 needs to be adjusted in real time according to the road adhesion coefficient after the second moment t2, while maximizing the use of road adhesion and avoiding tire burnout that affects power output and vehicle stability.

[0120] Among them, the road adhesion coefficient is the friction between the wheels and the road. The road adhesion coefficient has an important impact on the safety and stability of vehicle driving. The road adhesion coefficient is affected by many factors, including road material, humidity, temperature, tire type and wear degree. Under different road conditions and weather conditions, the corresponding road adhesion coefficient may be different.

[0121] In a related technology, it is proposed to coordinate the closed-loop adjustment of the vehicle slip rate of the vehicle through the Electronic Stability Control (ESC)-vehicle controller-motor controller 40. Specifically, when the torque output by the drive motor exceeds the road adhesion capacity, resulting in an abnormal increase in the wheel slip rate, the ESC will intervene and reduce the torque based on the wheel speed-vehicle speed. Since the ESC cannot identify the road capacity, when the reduced torque is too much, torque recovery is required. At this time, the torque output target of the drive motor will be restored to the torque value indicated by the torque command. However, when the torque corresponding to the torque command still exceeds the road adhesion capacity, the wheel will slip a second time, that is, during the process of ESC intervening to adjust the torque, the torque output by the drive motor will fluctuate significantly, affecting the driving experience.

[0122] The inventor of the present application found in the research that when the adhesion of the wheel on the road changes, the speed and torque of the drive motor used to drive the wheel will also change. Therefore, the change in the road adhesion can be sensed and observed through the change in the speed of the drive motor detected by the resolver sensor. The actual torque actually output by the drive motor reflects the adhesion of the road to a certain extent, so that the adhesion of the road can be accurately and quickly observed in real time according to the resolver signal and the torque signal. Specifically, the speed of the drive motor 30 can be obtained through the resolver signal of the resolver sensor, and the angular velocity of the wheel can be calculated by the speed of the drive motor 30 and the transmission ratio of the electric vehicle. The slip rate of each wheel can be obtained by combining the wheel radius and the speed of the electric vehicle 10, and then the adhesion of the road can be observed in real time according to the slip rate of the wheel.

[0123] In other words, the road adhesion observation in the present application can be realized based on the resolver signal, without the need to simultaneously collect the vehicle speed and wheel speed, with lower observation delay and higher accuracy. In addition, the torque closed-loop regulation in the present application can be realized in a closed loop inside the motor controller 40, which is conducive to shortening the communication link to reduce the control delay.

[0124] Further, in some embodiments, after the second moment t2, the drive motor 30 is actively controlled to adjust the torque output according to the resolver signal indicated by the resolver sensor so that the torque value output by the drive motor 30 is not equal to the torque value indicated by the torque signal.

[0125] It can be understood that active control refers to directly controlling the drive motor 30 to adjust the torque output through the motor controller 40, rather than controlling the drive motor 30 to adjust the torque output in response to the indication of the torque signal. Therefore, since the operation of the motor controller 40 and the drive motor 30 is decoupled from the vehicle controller, the torque output by the drive motor 30 will be unequal to the torque value indicated by the torque signal. At this time, the vehicle controller actually no longer performs torque control on the motor controller 40 and the drive motor 30, and the torque output by the drive motor 30 is unequal to the torque value indicated by the torque signal. Exemplarily, after the second moment t2, the torque output by the drive motor 30 may be less than the torque value indicated by the torque signal.

[0126] Exemplarily, in one embodiment, after the second moment t2, the rotation speed increase value of the drive motor 30 within the preset time length indicated by the resolver signal is greater than the preset change value, and the drive motor 30 is actively controlled to reduce the torque output.

[0127] It is understandable that after the electric vehicle 10 is launched, when the wheels move from a high-adhesion road surface (e.g., a dry paved road surface) to a low-adhesion road surface (e.g., a wet road surface, an icy road surface), since the torque required by the low-adhesion road surface is relatively small, if the drive motor 30 still outputs the torque value indicated by the torque signal, the driving force on the wheel will exceed the road adhesion limit, causing the wheel slip rate to increase, thereby driving the abnormal increase in the speed of the drive motor 30, causing the speed of the drive motor 30 to increase to greater than the preset speed within a preset time. In this scenario, it is necessary to control the drive motor 30 to reduce the torque output based on the torque value indicated by the torque signal, so that the driving force on the wheel matches the road adhesion capacity of the low-adhesion road surface, maximizing the use of the road adhesion capacity.

[0128] Similarly, after the second moment t2, if the speed reduction value of the drive motor 30 within the preset time length indicated by the resolver signal is greater than the preset speed, the drive motor 30 is actively controlled to increase the torque output.

[0129] It can be understood that after the electric vehicle 10 is launched, when the wheels move from a low-adhesion road surface to a high-adhesion road surface, since the torque required by the high-adhesion road surface is relatively large, if the drive motor 30 still outputs the torque value indicated by the torque signal, the driving force received by the wheels will be insufficient, resulting in a reduction in the slip rate of the wheels, thereby driving the abnormal reduction in the speed of the drive motor 30. In this scenario, it is necessary to control the drive motor 30 to increase the torque output based on the torque value indicated by the torque signal, so that the driving force received by the wheels matches the road adhesion of the low-adhesion road surface, maximizing the use of the road adhesion.

[0130] According to the embodiment of the present application, after the electric vehicle is launched, the drive motor is actively controlled to adjust the torque output according to the resolver signal, which can shorten the signal transmission link and further improve the control accuracy and immediacy.

[0131] According to the embodiment of the present application, by observing the road adhesion in real time and adjusting the torque output by the drive motor to keep the wheel slip rate in a stable range, it is possible to avoid tire burnout and affect power output and vehicle stability. In addition, the observation of road adhesion and the adjustment of the output torque of the drive motor in the present application are both implemented inside the drive system, with a shorter time delay, and can almost achieve microsecond (us)-level rapid observation and millisecond (ms)-level torque adjustment.

[0132] For more details, please refer to Figure 4 and Figure 5In one embodiment, at a third moment t3 after the second moment t2, the torque output by the drive motor 30 is controlled to increase from the first preset value to a value greater than the second preset value. At a fourth moment t4 after the third moment t3, the speed increase value within the preset time length indicated by the resolver signal is greater than the preset change value, and the torque output by the drive motor 30 is controlled to decrease to the first torque value.

[0133] Specifically, between the second moment t2 and the third moment t3, the drive motor 30 is first controlled to increase from the first preset value to the second preset value according to the instruction of the torque signal, thereby bringing greater acceleration to the electric vehicle 10. Between the third moment t3 and the fourth moment t4, the road adhesion is observed according to the resolver signal, and the torque output by the drive motor 30 is reduced to the first torque value according to the road adhesion. The first torque value can be understood as the maximum torque value matching the road load.

[0134] It can be understood that if after the third moment t3, the speed increases or decreases to a value less than the preset change value within the preset time period indicated by the resolver signal, the torque output by the control drive motor 30 is maintained at the second preset value.

[0135] According to the embodiment of the present application, it is proposed to observe the road adhesion in real time through the resolver signal, and when the driving force corresponding to the torque signal is greater than the road adhesion capacity, the drive motor is actively controlled to adjust the output torque based on the road adhesion. In this way, since the torque output by the drive motor matches the road adhesion, there is no need to perform torque recovery, and the wheels will not slip again, thereby reducing the torque fluctuation output by the drive motor and improving the driving experience.

[0136] In one embodiment, after the second moment t2, the drive motor 30 is actively controlled to adjust the torque output according to the resolver signal indicated by the resolver sensor, while another drive motor coaxial with the drive motor 30 is controlled to adjust the torque output so that the torque output by the drive motor 30 is equal to that of the other drive motor.

[0137] It is understandable that after the electric vehicle 10 is launched, the wheels on both sides may contact road surfaces with different adhesion capabilities. For example, when one wheel passes over a flooded road surface, if only the drive motor 30 is controlled to adjust the torque output, the two coaxial wheels will receive unequal driving forces, which will cause the force balance of the entire vehicle to be destroyed, making it difficult to maintain the vehicle's straight-line driving, affecting the user experience and even potentially causing safety hazards. In response to this scenario, the present application proposes to actively adjust the torque output of one drive motor according to the resolver signal while adjusting the torque output of another coaxial drive motor to ensure that the driving forces on the wheels on both sides are equal, so that the vehicle can maintain straight-line driving after starting. For example, for example Figure 3The electric vehicle 10 shown in (a) controls the drive motor 31 to reduce the torque output according to the resolver signal after the second moment t2, and also actively controls the drive motor 32 to reduce the torque output so that the torques output by the drive motors 31 and 32 are equal.

[0138] According to the embodiment of the present application, for an electric vehicle with a distributed power architecture, controlling the torque output by two coaxial drive motors to maintain a dynamic balance is beneficial to improving the safety and reliability of the launch function.

[0139] In one embodiment, after the second moment t2, when the speed of the electric vehicle 10 is greater than the preset speed, the opening of the brake pedal increases from zero to the second brake pedal opening, or the opening of the accelerator pedal of the electric vehicle 10 decreases to less than the first accelerator pedal opening, the launch control function is turned off.

[0140] It can be understood that the preset vehicle speed is a relatively high vehicle speed. After the electric vehicle 10 accelerates to the preset vehicle speed after the launch start, the launch process of the electric vehicle 10 can be completed. At this time, the launch start function can be controlled to be turned off. The second brake pedal opening is a relatively small opening value. During the launch start process, if the brake pedal opening increases from zero to the second brake pedal opening, or during the launch start process, if the accelerator pedal opening of the electric vehicle 10 decreases to less than the first accelerator pedal opening, it can be understood that the user expects the vehicle to stop accelerating. In this way, in order to meet user expectations, the control method provided in the embodiment of the present application will control the launch start function of the electric vehicle 10 to be turned off.

[0141] It is understandable that after the launch function is turned off, if the user expects to perform the next launch function, the launch function needs to be enabled again according to the above method.

[0142] According to an embodiment of the present application, during the launch-start process of an electric vehicle, when the vehicle speed reaches a preset speed or the user actively steps on the brake pedal or actively releases the accelerator pedal, the launch-start function is controlled to be turned off. The flexibility of turning off the launch-start function is high, and the safety and reliability of the launch-start function of the electric vehicle are stronger.

[0143] Combine the following Figure 6 and Figure 7 The control architecture of the vehicle controller and the control process of the launch control provided in the embodiment of the present application are described.

[0144] It can be understood that the vehicle controller provided in the present application can be a vehicle controller 20, a motor controller 40, or other separately set controller with control capabilities.

[0145] In one embodiment, the vehicle controller can be mounted in a separate power domain controller or in the motor controller 40. If it is mounted in the motor controller 40, the chassis CAN information needs to be transmitted to the motor controller 40 side, and the motor controller 40 directly monitors the change of the road adhesion ability in real time according to the rotary signal on the drive motor 30 side, thereby realizing the torque closed-loop control at the 1ms level. The motor controller sends the braking signal to the braking system 60, so that the drive system and the braking system 60 cooperate to achieve the launch start.

[0146] In one embodiment, the vehicle controller can also be installed in the vehicle controller 20. The motor controller sends the rotary transformer signal or the detected change in road adhesion to the vehicle controller 20 through CAN communication. The vehicle controller 20 analyzes the torque demand based on the opening of the accelerator pedal and the change in road adhesion, sends the torque signal to the motor controller 40, and sends the brake signal to the brake system 60, so that the drive system and the brake system 60 cooperate to achieve launch start.

[0147] The vehicle controller can integrate longitudinal and lateral control into the same controller, coordinate driving and braking control, realize joint control, reduce time delay, and improve control accuracy and response speed.

[0148] Combination Figure 3 , Figure 4 as well as Figure 6 In one embodiment, at a first time t1 after the opening of the brake pedal is greater than the first brake pedal opening and the opening of the accelerator pedal is greater than the first accelerator pedal opening, the brake system 60 is controlled to output a braking force to the wheels of the electric vehicle 10 and the drive motor 30 is controlled to output a torque to the wheels of the electric vehicle 10. At a second time t2 after the first time t1, the opening of the brake pedal decreases to less than the second brake pedal opening and the opening of the accelerator pedal is greater than the first accelerator pedal opening, the braking force output by the brake system 60 is controlled to decrease and the torque output by the drive motor 30 is controlled to increase.

[0149] like Figure 3 and Figure 4As shown, in one embodiment, the brake pedal sensor of the electric vehicle 10 is used to detect the opening of the brake pedal, and the accelerator pedal sensor is used to detect the opening of the accelerator pedal. At the first moment t1, the brake pedal sensor detects that the brake pedal opening is greater than the first brake pedal opening, and the accelerator pedal sensor detects that the accelerator pedal opening is greater than the first accelerator pedal opening, and the vehicle controller sends a first braking command to the braking system, and sends a first torque command to the drive system. Correspondingly, the braking system outputs braking force in response to the first braking command, and the drive system outputs torque in response to the first torque command. At the second moment t2 after the first moment t1, the brake pedal sensor detects that the brake pedal opening is reduced to less than the second brake pedal opening, and the accelerator pedal sensor detects that the accelerator pedal opening is still greater than the first accelerator pedal opening, and the vehicle controller sends a second braking command to the braking system and sends a second torque command to the drive system. Correspondingly, the braking system reduces the braking force output in response to the second braking command, and the drive system increases the torque output in response to the first torque command.

[0150] According to the embodiment of the present application, the vehicle controller can control the drive motor to load torque in advance before the electric vehicle starts and control the brake system to output braking force to keep the vehicle stationary, and then control the drive system to increase the torque output and control the brake system to reduce the braking force output, so as to achieve launch start. In this way, after the launch start function is enabled, the user can control the vehicle to achieve launch start through the brake pedal and the accelerator pedal, which is simple and intuitive to operate, with low learning cost for users, which is conducive to improving user experience.

[0151] Continue to refer Figure 3 and Figure 4 In one embodiment, between the first moment t1 and the second moment t2, the vehicle controller can control the torque loading mark displayed on the central control screen to change with the torque output of the drive motor 30 according to the torque actually output by the drive motor 30 detected by the torque observer. At the second moment t2, when the torque observer observes that the torque actually output by the drive motor 30 reaches the torque value indicated by the first torque command, the central control screen is controlled to stop displaying the torque loading mark and display the launch start mark.

[0152] According to an embodiment of the present application, the vehicle controller can control the display of the torque loading mark and the launch start mark on the central control screen of the electric vehicle, and control the torque loading mark to dynamically change with the torque output of the drive motor, so that the user can get a stronger visual impact while confirming the current torque output of the drive motor, thereby further improving the user experience.

[0153] Continue to refer Figure 3 and Figure 4In one embodiment, at a third moment t3 after the second moment t2, the drive system outputs a second preset value indicated by the second torque instruction. At a fourth moment t4 after the third moment t3, the drive system actively controls the drive motor to reduce the torque output to a first torque value in response to the rotation speed change rate of the drive motor indicated by the resolver signal being greater than the preset change rate. The first torque value can be understood as a maximum torque value that matches the road load.

[0154] When the wheel's adhesion to the road changes, the speed and torque of the drive motor used to drive the wheel will also change. Therefore, the change in the road adhesion can be sensed and observed through the change in the speed of the drive motor detected by the resolver sensor. The actual torque actually output by the drive motor reflects the adhesion of the road to a certain extent, so that the adhesion of the road can be accurately and quickly observed in real time according to the resolver signal and the torque signal. Specifically, the speed of the drive motor 30 can be obtained through the resolver signal of the resolver sensor, and the angular velocity of the wheel can be calculated by the speed of the drive motor 30 and the transmission ratio of the electric vehicle. The slip rate of each wheel can be obtained by combining the wheel radius and the speed of the electric vehicle 10, and then the adhesion of the road can be observed in real time according to the slip rate of the wheel.

[0155] In other words, the drive system can observe the road adhesion ability in real time according to the resolver signal indicated by the resolver sensor, and actively reduce the torque output when the torque indicated by the torque command exceeds the road adhesion ability, thereby realizing closed-loop control of the wheel slip rate.

[0156] According to the solution of the present application, the drive system can observe the road adhesion in real time according to the resolver signal indicated by the resolver sensor, and actively reduce the torque output when the torque indicated by the torque command exceeds the road adhesion, so that the actual output torque matches the road adhesion, which can avoid tire burnout and affect power output and vehicle stability. In addition, the above-mentioned observation of road adhesion and closed-loop torque regulation are all implemented inside the drive system, with shorter time delay, and can almost achieve microsecond (us) level fast observation and millisecond (ms) level torque regulation.

[0157] like Figure 7 As shown, the control process of ejection start is as follows:

[0158] First, the vehicle controller first inputs signals, including brake pedal signal, accelerator pedal signal, launch enable signal, drive motor torque, drive motor speed, etc.

[0159] Then, the vehicle controller detects whether the launch function is enabled, and controls the braking force output by the brake system and the driving torque output by the drive system according to the brake pedal opening and the accelerator pedal opening after detecting that the launch function is enabled. In addition, when the drive system outputs the driving torque, the motor controller calculates the torque value corresponding to the road adhesion capacity corresponding to the current wheel / axle according to the motor speed, the torque signal and the actual output torque.

[0160] It can be understood that the specific control method of the launch control can be referred to as described above and will not be elaborated here.

[0161] Finally, when the motor controller detects that the torque value indicated by the torque signal exceeds the torque value corresponding to the road adhesion capacity, the motor controller actively controls the drive motor to reduce the torque output so that the torque value actually output by the drive motor matches the torque value corresponding to the road adhesion capacity, thereby achieving smooth output of the drive torque during launch.

[0162] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A control method for launching an electric vehicle, characterized in that: The control method is used to control the launch start of the electric vehicle after the launch start function of the electric vehicle is activated, and the control method includes: At a first moment after the opening of the brake pedal of the electric vehicle is greater than the first brake pedal opening and the opening of the accelerator pedal of the electric vehicle is greater than the first accelerator pedal opening, controlling the brake system to output braking force to the wheels of the electric vehicle and controlling the drive motor to output torque to the wheels of the electric vehicle; At a second moment after the first moment, the opening of the brake pedal decreases to less than the second brake pedal opening and the opening of the accelerator pedal is greater than the first accelerator pedal opening, the braking force output by the brake system is controlled to decrease and the torque output by the drive motor is controlled to increase.

2. The control method according to claim 1, characterized in that: The control method further comprises: After the second moment, the braking force output by the braking system is controlled to be zero and the torque output by the driving motor is controlled to increase to a preset value.

3. The control method according to claim 1, characterized in that: The control method further comprises: Before the second moment, controlling the drive motor to output the torque indicated by the torque signal; After the second moment, the drive motor is actively controlled to adjust the torque output according to the resolver signal indicated by the resolver sensor.

4. The control method according to claim 3, characterized in that: The control method specifically includes: After the second moment, the drive motor is actively controlled to adjust the torque output according to the resolver signal indicated by the resolver sensor so that the torque value output by the drive motor is not equal to the torque value indicated by the torque signal.

5. The control method according to claim 4, characterized in that: The control method specifically includes: After the second moment, if the increase in speed of the drive motor within the preset time period indicated by the resolver signal is greater than the preset speed change value, the drive motor is actively controlled to reduce the torque output.

6. The control method according to claim 5, characterized in that: The control method further comprises: After the second moment, the drive motor is actively controlled to adjust the torque output according to the resolver signal indicated by the resolver sensor, and another drive motor coaxial with the drive motor is controlled to adjust the torque output so that the torque output of the drive motor and the another drive motor are equal.

7. The control method according to any one of claims 3 to 6, characterized in that: The control method further comprises: Between the first moment and the second moment, controlling the torque value indicated by the torque signal to be a first preset value; After the second moment, the torque value indicated by the torque signal is controlled to be a second preset value greater than the first preset value.

8. The control method according to claim 7, characterized in that: The control method specifically includes: At a third moment after the second moment, controlling the torque output by the drive motor to increase from the first preset value to the second preset value; At a fourth moment after the third moment, the speed increase value of the drive motor within the preset time length indicated by the resolver signal is greater than the preset speed change value, and the torque output by the drive motor is controlled to be reduced to the first torque value.

9. The control method according to any one of claims 1 to 8, characterized in that: The control method further comprises: Between the first moment and the second moment, the braking force output by the braking system is controlled to increase as the torque output by the driving motor increases.

10. The control method according to claim 1, characterized in that: The control method further comprises: Between the first moment and the second moment, controlling the central control screen of the electric vehicle to display a torque loading mark and controlling the torque loading mark to change with the torque output by the drive motor; At the second moment, the central control screen is controlled to stop displaying the torque loading mark and display the launch start mark.

11. The control method according to claim 1, characterized in that: The control method further comprises: After the second moment, when the speed of the electric vehicle is greater than the preset speed, the opening of the brake pedal increases from zero to a second brake pedal opening, or the opening of the accelerator pedal of the electric vehicle decreases to less than the first accelerator pedal opening, the launch control function is controlled to be turned off.

12. A vehicle controller for an electric vehicle, characterized in that: The controller is configured to execute the vehicle control method according to any one of claims 1 to 11.

13. An electric vehicle, characterized in that: The electric vehicle includes a drive system, a braking system and a controller as claimed in claim 12, wherein the drive system is used to drive the four wheels of the electric vehicle to rotate, the braking system is used to output braking force to the four wheels, and the controller is used to control the drive system and the braking system to perform the control method as described in any one of claims 1 to 11.

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