CN115056788A

CN115056788A - Control method and control system of electric automobile

Info

Publication number: CN115056788A
Application number: CN202210697011.4A
Authority: CN
Inventors: 王奕文; 连凤霞; 姜峰
Original assignee: Weichai Power Co Ltd; Weifang Weichai Power Technology Co Ltd
Current assignee: Weichai Power Co Ltd; Weifang Weichai Power Technology Co Ltd
Priority date: 2022-06-20
Filing date: 2022-06-20
Publication date: 2022-09-16
Anticipated expiration: 2042-06-20
Also published as: CN115056788B

Abstract

The embodiment of the invention discloses a control method and a control system of an electric automobile, which comprise the following steps: acquiring a fault trigger signal, and analyzing according to the fault trigger signal to determine a first fault type; comparing the first fault type with a preset fault type, and determining that the first fault type is the preset fault type; acquiring a first external instruction signal, and judging whether the first external instruction signal is consistent with a first preset signal or not; if the first external instruction signal is consistent with the first preset signal, controlling the electric automobile to enter a first working state, wherein the first working state comprises a limp working state; and if the first external command signal is inconsistent with the first preset signal, controlling the electric automobile to enter a second working state, wherein the second working state comprises a high-voltage low-voltage state. The technical scheme provided by the embodiment of the invention is used for perfecting the controllability of the electric automobile on fault treatment when serious faults occur, and improving the safety and the intellectualization of the electric automobile.

Description

Control method and control system of electric automobile

Technical Field

The embodiment of the invention relates to the technical field of electric automobiles, in particular to a control method and a control system of an electric automobile.

Background

With the increasing energy crisis and environmental pollution, electric vehicles are becoming a necessary trend for the development of the automotive industry due to the advantages of high efficiency, energy saving and zero emission.

When a general fault occurs in the existing electric automobile, the electric automobile can directly enter a limp home control mode, the speed of the electric automobile is limited, and the power of the electric automobile is limited, namely the conventional fault degradation treatment is carried out. When the electric automobile has serious faults, the automobile can be directly subjected to torque clearing and high-voltage power-off operation, and at the moment, if the automobile is in a dangerous zone, such as the middle of a highway or a crossroad and the like, traffic jam and even safety accidents can be caused, and great potential safety hazards exist.

Disclosure of Invention

The invention provides a control method and a control system of an electric automobile, which are used for perfecting the controllability of the electric automobile on fault treatment when serious faults occur and improving the safety and the intellectualization of the electric automobile.

In a first aspect, an embodiment of the present invention provides a control method for an electric vehicle, where a fault trigger signal is obtained, and a first fault type is determined by analyzing according to the fault trigger signal;

comparing the first fault type with a preset fault type, and determining that the first fault type is the preset fault type;

acquiring a first external instruction signal, and judging whether the first external instruction signal is consistent with a first preset signal or not;

if the first external command signal is consistent with a first preset signal, controlling the electric automobile to enter a first working state, wherein the first working state comprises a limp working state;

and if the first external instruction signal is inconsistent with the first preset signal, controlling the electric automobile to enter a second working state, wherein the second working state comprises high-voltage reduction or motor torque zero clearing.

In a second aspect, an embodiment of the present invention further provides a control system of an electric vehicle, where the electric vehicle includes a vehicle controller, and the vehicle controller is configured to execute the control method of the electric vehicle according to the first aspect.

According to the technical scheme of the embodiment of the invention, the fault type of the electric automobile can be accurately determined by acquiring the fault trigger signal and analyzing and determining the first fault type according to the fault trigger signal, then the first fault type is compared with the preset fault type, and the first fault type is determined to be the preset fault type. And then continuously acquiring the first external instruction signal, and judging whether the first external instruction signal is consistent with the first preset signal or not so as to further determine whether the first external instruction signal which is the same as the first preset signal and the first preset signal is received or not, if the first external instruction signal is consistent with the first preset signal, controlling the electric automobile to enter a first working state, immediately entering a limp working state, and enabling the electric automobile to slowly run to a safety zone. On the contrary, if the first external instruction signal is inconsistent with the first preset signal, the electric automobile is controlled to enter a second working state, high-voltage power-off operation or motor torque zero clearing is carried out on the electric automobile, and safety accidents are avoided. Therefore, the working state of the electric automobile can still be selectively controlled when a serious fault occurs, so that the electric automobile has certain controllability on fault treatment when the serious fault occurs, and the safety and the intelligence of the electric automobile are improved.

It should be understood that the statements in this section are not intended to identify key or critical features of the embodiments of the present invention, nor are they intended to limit the scope of the invention. Other features of the present invention will become apparent from the following description.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a flowchart of a control method for an electric vehicle according to an embodiment of the present invention;

FIG. 2 is a flowchart illustrating another method for controlling an electric vehicle according to an embodiment of the present invention;

fig. 3 is a flowchart of a control method for an electric vehicle according to another embodiment of the present invention;

fig. 4 is a flowchart of a control method for another electric vehicle according to an embodiment of the present invention;

fig. 5 is a flowchart of a control method for another electric vehicle according to an embodiment of the present invention;

fig. 6 is a flowchart of a control method for an electric vehicle according to another embodiment of the present invention;

fig. 7 is a flowchart of a control method for an electric vehicle according to another embodiment of the present invention;

fig. 8 is a flowchart of a control method for an electric vehicle according to another embodiment of the present invention;

fig. 9 is a flowchart of a control method for an electric vehicle according to another embodiment of the present invention;

fig. 10 is a schematic structural diagram of a control system of an electric vehicle according to an embodiment of the present invention.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

Fig. 1 is a flowchart of a control method of an electric vehicle according to an embodiment of the present invention, and as shown in fig. 1, the control method mainly includes the following steps:

s101, acquiring a fault trigger signal, and analyzing according to the fault trigger signal to determine a first fault type.

The fault trigger signal may be a digital signal or an analog signal, which is not limited in the embodiment of the present invention. It can be understood that, because there are many control signals in the electric vehicle, the general fault trigger signal is a fault code composed of multi-bit binary digits, and the fault trigger signals corresponding to different faults are different. The first fault type corresponding to the fault trigger signal can be determined by further analyzing the received fault trigger signal.

The first fault type includes, but is not limited to, faults such as battery, motor, brake device, communication and power supply circuit, etc., and faults for the same device are also classified into different fault classes, such as minor fault, general fault, and major fault. In the prior art, a slight fault is displayed through an instrument panel in an electric automobile to remind a driver, but the control logic of the electric automobile is not processed; for general faults, speed limit and torque limit processing, namely fault degradation processing generally referred to by a person skilled in the art, can be performed on the whole vehicle; aiming at serious faults, the motor in the electric automobile can be directly subjected to torque zero clearing and even forced high-voltage descending operation.

S102, comparing the first fault type with a preset fault type, and determining that the first fault type is the preset fault type.

The preset fault type refers to a serious fault occurring in the electric automobile, and the specific fault type includes, but is not limited to, a high-voltage interlock fault caused by a high-voltage loop fault, a brake pedal sensor fault, a charging interlock fault caused by abnormal charging state of the electric automobile, and the like.

Specifically, the preset fault type may be a preset fault type in the system, and the first fault type and the preset fault type are compared one by one to further determine that the first fault type is the preset fault type.

S103, acquiring a first external instruction signal, and judging whether the first external instruction signal is consistent with a first preset signal. If the first external command signal is consistent with the first preset signal, step S104 is performed, and if the first external command signal is inconsistent with the first preset signal, step S105 is performed.

The first external instruction signal may be generated by operation and triggering of a driver, and a specific generation manner of the first external instruction signal is not limited in the embodiment of the present invention, for example, the driver presses a double-flashing button to generate the first external instruction signal. The first external instruction signal may be a digital signal or an analog signal, which is not limited in this embodiment of the present invention.

Specifically, after the first external instruction signal is acquired, the first external instruction signal is compared with a first preset signal to judge whether the first external instruction signal is an effective signal, and it can be understood that the effective signal refers to a signal generated by a driver performing a corresponding operation to trigger generation of the corresponding first external instruction signal. Further, depending on the determination result, the operation to be continuously performed next may be different.

And S104, controlling the electric automobile to enter a first working state, wherein the first working state comprises a limp-home working state.

The limp work state refers to control of the electric automobile to enter a limp mode, and generally limits the speed and power of the electric automobile so as to avoid safety accidents caused by the fact that the speed of the electric automobile is large and the like.

Specifically, if the first external command signal is consistent with the first preset signal, the electric vehicle is controlled to enter a limp working state, so that the electric vehicle slowly runs to a safe place under the conditions of limited vehicle speed and limited power, and a driver can perform maintenance or wait for rescue again, thereby avoiding safety accidents.

And S105, controlling the electric automobile to enter a second working state, wherein the second working state comprises high-voltage reduction or motor torque zero clearing.

The high-voltage power-off operation refers to the power-off operation of high-voltage output electricity of a power battery in the electric automobile (namely power electricity for driving the electric automobile to run). It is understood that the high voltage power-OFF operation may be performed by a vehicle control unit in the system, or may be performed by a manual operation performed by a driver (for example, turning OFF a start key of the vehicle or turning a start key to an OFF gear), which is not limited in the embodiment of the present invention. According to different fault types, the specific operation mode of high-voltage power supply can be different, and the setting can be carried out according to the actual situation.

Specifically, according to the difference of the first fault type, under the condition that the first external instruction signal is inconsistent with the first preset signal, the second working state of the electric vehicle is different. For example, if the first fault type is a serious high-voltage interlock fault, the electric vehicle is required to be subjected to high voltage reduction so as to avoid safety accidents, and if the first fault type is a charging interlock fault or a brake pedal sensor fault, the electric vehicle is not required to be subjected to high voltage reduction, and only the output torque of the motor is controlled to be zero. It is understood that those skilled in the art can make selective settings according to the circumstances, and the embodiments of the present invention are not limited thereto.

In the embodiment of the invention, the fault type of the electric automobile can be accurately determined by acquiring the fault trigger signal and analyzing and determining the first fault type according to the fault trigger signal, then the first fault type is compared with the preset fault type to determine that the first fault type is the preset fault type, and it can be understood that the next fault processing operation can be accurately performed by determining whether the first fault type is the preset fault type, and the subsequent operation can be continuously executed after the first fault type is determined to be the preset fault type. And then continuously acquiring the first external instruction signal, and judging whether the first external instruction signal is consistent with the first preset signal or not so as to further determine whether the first external instruction signal which is the same as the first preset signal is received or not, and if the first external instruction signal is consistent with the first preset signal, controlling the electric automobile to immediately enter a limp working state so that the electric automobile slowly runs to a safety zone. On the contrary, if the first external instruction signal is inconsistent with the first preset signal, the electric automobile is controlled to enter a second working state, high-voltage power-off operation or motor torque zero clearing is carried out on the electric automobile, and safety accidents are avoided. Therefore, the working state of the electric automobile can still be selectively controlled when a serious fault occurs, so that the electric automobile has certain controllability on fault treatment when the serious fault occurs, and the safety and the intelligence of the electric automobile are improved.

Optionally, fig. 2 is a flowchart of another control method for an electric vehicle according to an embodiment of the present invention, and as shown in fig. 2, the preset fault type includes a high-voltage interlock fault, and the second operating state includes a high-voltage low-voltage; before acquiring a first external instruction signal and judging whether the first external instruction signal is consistent with a first preset signal, the method comprises the following steps: judging whether the electric automobile completes high-voltage power-on; if the electric automobile does not finish high-voltage electrification, controlling the electric automobile to forbid high-voltage electrification operation; and if the electric automobile is electrified at high voltage, continuously acquiring the first external instruction signal, and judging whether the first external instruction signal is consistent with the first preset signal. Therefore, the control method includes the steps of:

s201, acquiring a fault trigger signal, and analyzing according to the fault trigger signal to determine a first fault type.

S202, comparing the first fault type with a preset fault type, and determining that the first fault type is the preset fault type.

Specifically, the predetermined fault type includes a high-voltage interlock fault, and it is understood that the high-voltage interlock fault is usually triggered by an abnormality in the high-voltage circuit.

S203, judging whether the electric automobile is powered on at high voltage. If the electric vehicle does not complete the high voltage power-on, step S204 is performed, and if the electric vehicle does complete the high voltage power-on, step S205 is performed.

Specifically, whether high-voltage power-on is completed or not can be determined according to whether the output voltage of the power battery in the electric automobile meets a preset value or not, and it can be understood that if the electric automobile completes high-voltage power-on, the electric automobile can enter a running state at any time.

And S204, controlling the electric automobile to prohibit high-voltage electrifying operation.

Specifically, if the electric vehicle does not finish high-voltage power-on, the electric vehicle fails, and the electric vehicle is prohibited from high-voltage power-on.

S205, acquiring a first external instruction signal, and judging whether the first external instruction signal is consistent with a first preset signal. If the first external command signal is consistent with the first preset signal, step S206 is performed, and if the first external command signal is inconsistent with the first preset signal, step S207 is performed.

And S206, controlling the electric automobile to enter a first working state, wherein the first working state comprises a limp-home working state.

And S207, controlling the electric automobile to enter a second working state, wherein the second working state comprises high-voltage low-voltage.

In this embodiment, when the first fault type is determined to be a high-voltage interlocking fault in the preset fault types by obtaining the fault trigger signal and analyzing the fault trigger signal to determine the first fault type, and then comparing the first fault type with the preset fault types, it is necessary to further determine that the electric vehicle has completed the high-voltage power-on operation at this time. If the high-voltage electrifying operation is not finished, the high-voltage electrifying operation is carried out on the electric automobile, and if the high-voltage electrifying operation is finished, the subsequent work state can be carried out according to whether the first external instruction signal is obtained or not. Specifically, if the first external instruction signal is consistent with the first preset signal, the electric vehicle is controlled to enter a first working state and immediately enter a limp working state, so that the electric vehicle slowly runs to a safety zone, and if the first external instruction signal is inconsistent with the first preset signal, the electric vehicle is controlled to enter a second working state, so that the electric vehicle is subjected to high-voltage power-off operation, and safety accidents are avoided. Therefore, different control operations can be performed according to different specific time when the high-voltage interlocking fault occurs, so that the electric automobile has certain controllability on fault treatment when serious faults occur, and the safety and the intelligence of the electric automobile are improved.

Optionally, fig. 3 is a flowchart of another control method for an electric vehicle according to an embodiment of the present invention, as shown in fig. 3, on the basis of fig. 2, if the electric vehicle does not complete high-voltage power-on, after controlling the electric vehicle to prohibit the high-voltage power-on operation, the method further includes: acquiring a first external instruction signal, and judging whether the first external instruction signal is consistent with a first preset signal or not; if the first external instruction signal is consistent with the first preset signal, controlling the electric automobile to enter a third working state, wherein the third working state comprises high-voltage power-on operation and early warning prompt, and after the high-voltage power-on is finished, controlling the electric automobile to enter a first working state, and the first working state comprises a limp working state; and if the first external command signal is inconsistent with the first preset signal, controlling the electric automobile to prohibit high-voltage electrifying operation. Therefore, the control method mainly comprises the following steps:

s301, acquiring a fault trigger signal, and analyzing according to the fault trigger signal to determine a first fault type.

S302, comparing the first fault type with a preset fault type, and determining that the first fault type is the preset fault type.

And S303, judging whether the electric automobile is electrified at high voltage or not. If the electric vehicle does not complete the high voltage power-on, step S304 is performed, and if the electric vehicle does complete the high voltage power-on, step S308 is performed.

And S304, controlling the electric automobile to prohibit high-voltage electrifying operation.

S305, acquiring a first external instruction signal, and judging whether the first external instruction signal is consistent with a first preset signal.

At this time, if the first external command signal is obtained to be consistent with the first preset signal after the electric vehicle prohibits the high-voltage power-on operation, step S306 is executed, and conversely, if the first external command signal is inconsistent with the first preset signal after the electric vehicle prohibits the high-voltage power-on operation, step S304 is returned to.

And S306, controlling the electric automobile to enter a third working state, wherein the third working state comprises high-voltage electrifying operation and early warning prompt.

The early warning prompt may be an icon prompt through an instrument panel of the electric vehicle, or a warning sound may be generated simultaneously when the instrument panel performs the icon prompt, which is not particularly limited in the embodiment of the present invention.

And S307, judging whether the electric automobile is electrified at high voltage or not. And after the high voltage power-on is completed, step S309 is performed.

S308, acquiring the first external instruction signal, and judging whether the first external instruction signal is consistent with the first preset signal.

S309, controlling the electric automobile to enter a first working state, wherein the first working state comprises a limp-home working state.

And S310, controlling the electric automobile to enter a second working state, wherein the second working state comprises a high-voltage low-voltage state.

Specifically, after a high-voltage interlocking fault occurs before the electric vehicle is powered on at a high voltage, the electric vehicle is prohibited from being powered on at the high voltage, and at this time, if the first external instruction signal is obtained and is consistent with the first preset signal, the electric vehicle can be forcibly powered on at the high voltage. And in the process of high-voltage electrification, monitoring whether other faults occur in the electric automobile, and if other faults do not occur and the high-voltage electrification can be completed, indicating that the high-voltage interlocking fault reported before the electric automobile is possibly false alarm or fault information is not cleared. At the moment, after the electric automobile is electrified at high voltage, the electric automobile is controlled to enter a limping working state, so that the electric automobile slowly runs to a safe zone, the electric automobile is further overhauled, and the safety of the electric automobile is determined.

Optionally, fig. 4 is a flowchart of another control method for an electric vehicle according to an embodiment of the present invention, as shown in fig. 4, if the electric vehicle has completed high-voltage power-on and the first external command signal is consistent with the first preset signal, before controlling the electric vehicle to enter the first working state, where the first working state includes a limp-home working state, the method further includes: and judging that the electric automobile has driving conditions, wherein the driving conditions comprise that a motor control loop of the electric automobile completes pre-charging. Therefore, the control method includes the steps of:

s401, acquiring a fault trigger signal, and analyzing according to the fault trigger signal to determine a first fault type.

S402, comparing the first fault type with a preset fault type, and determining that the first fault type is the preset fault type.

And S403, judging whether the electric automobile is powered on at high voltage or not. If the electric vehicle does not finish the high voltage power-on, step S404 is executed, and if the electric vehicle finishes the high voltage power-on, step S405 is executed.

And S404, controlling the electric automobile to prohibit high-voltage electrifying operation.

S405, acquiring a first external instruction signal, and judging whether the first external instruction signal is consistent with a first preset signal. If the first external command signal is consistent with the first preset signal, step S406 is performed, and if the first external command signal is inconsistent with the first preset signal, step S408 is performed.

And S406, judging that the electric automobile has driving conditions, wherein the driving conditions comprise that the motor control loop of the electric automobile completes pre-charging.

It can be understood that the dc high voltage power output by the power battery in the electric vehicle is provided to the motor control loop, so that the motor can drive the electric vehicle to run. Because the motor is a three-phase motor, usually, the motor control circuit further comprises an inverter circuit and a bus capacitor, before the electric automobile can stably drive, the bus capacitor in the motor control circuit needs to be precharged to ensure the stable operation of the motor, so that the electric automobile can reliably drive, namely, the driving condition is met.

For example, by collecting the motor voltage, when the motor voltage is determined to be greater than or equal to 90% of the output voltage of the power battery, the motor control loop of the electric vehicle can be determined to complete the pre-charging.

S407, controlling the electric automobile to enter a first working state, wherein the first working state comprises a limp-home working state.

And S407, controlling the electric automobile to enter a second working state, wherein the second working state comprises high-voltage reduction.

In the embodiment of the invention, after the first external instruction signal is acquired and the first external instruction signal is judged to be consistent with the first preset signal, whether the motor control loop of the electric automobile is precharged or not needs to be further determined, so that the electric automobile can stably work after entering a limp working state, and safety accidents are avoided.

Optionally, fig. 5 is a flowchart of a control method for an electric vehicle according to an embodiment of the present invention, as shown in fig. 5, on the basis of any one of the foregoing embodiments, if the first external command signal is inconsistent with the first preset signal, before controlling the electric vehicle to enter a second operating state, where the second operating state includes a high-voltage low-voltage state, the method includes: controlling the output torque of a motor in the electric automobile to be zero; and acquiring the speed of the electric automobile, and controlling the electric automobile to enter a second working state when the speed of the electric automobile is judged to be less than a preset speed threshold value, wherein the second working state comprises high-voltage low-voltage. Therefore, the control method includes the steps of:

s501, acquiring a fault trigger signal, and analyzing according to the fault trigger signal to determine a first fault type.

S502, comparing the first fault type with a preset fault type, and determining that the first fault type is the preset fault type.

S503, acquiring a first external instruction signal, and judging whether the first external instruction signal is consistent with a first preset signal. If the first external command signal is consistent with the first preset signal, step S504 is executed, and if the first external command signal is inconsistent with the first preset signal, step S505 is executed.

And S504, controlling the electric automobile to enter a first working state, wherein the first working state comprises a limp-home working state.

And S505, controlling the output torque of a motor in the electric automobile to be zero.

Specifically, the output torque of the electric vehicle control motor may be slowly reduced to zero at a certain rate, or the output torque of the electric vehicle control motor may be gradually reduced to zero in a step shape.

S506, obtaining the speed of the electric automobile, and judging that the speed of the electric automobile is smaller than a preset speed threshold value.

The specific size of the preset vehicle speed threshold is not limited in the embodiment of the present invention, and is, for example, 5 km/h.

And S507, controlling the electric automobile to enter a second working state, wherein the second working state comprises high-voltage reduction.

In this embodiment, because the output torque of the motor is about zero, the speed of the electric vehicle is gradually reduced, the speed of the electric vehicle is monitored in real time in the process, and is compared with the preset speed threshold, and when the speed of the electric vehicle is smaller than the preset speed threshold, the electric vehicle can be controlled to directly perform high-voltage reduction. So, avoid when first outside command signal is inconsistent with first preset signal, directly carry out the high voltage down-voltage to electric automobile, damage the device among the electric automobile, guarantee electric automobile's security, simultaneously, avoid electric automobile's the speed of a motor vehicle too high, directly carry out the high voltage down-voltage of forcing and lead to the fact the security threat to the driver.

It should be noted that, when the first fault type is a high-voltage interlock fault, after the output torque of the motor is cleared, the controller in the system directly forces the electric vehicle to perform high-voltage and low-voltage operations, so as to avoid safety accidents.

Optionally, fig. 6 is a flowchart of a control method of another electric vehicle according to an embodiment of the present invention, as shown in fig. 6, on the basis of fig. 1, the preset fault type includes a brake pedal sensor fault, and the second operating state includes a motor torque zero clearing; before acquiring a first external instruction signal and judging whether the first external instruction signal is consistent with a first preset signal, the method comprises the following steps: and judging that the electric automobile is in a forward driving state. Therefore, the control method includes the steps of:

s601, acquiring a fault trigger signal, and analyzing according to the fault trigger signal to determine a first fault type.

S602, comparing the first fault type with a preset fault type, and determining that the first fault type is the preset fault type.

Specifically, the preset fault type includes a brake pedal sensor fault, and the brake pedal sensor fault refers to a condition that a voltage signal detected by a brake pedal sensor exceeds a lower limit value of a normal range. It can be understood that the brake pedal sensor is usually arranged in a brake control loop in the electric automobile to be used for carrying out accurate control on the braking of the electric automobile, if the brake pedal sensor breaks down, the electric automobile cannot be normally braked, and therefore safety accidents are easily caused.

And S603, judging that the electric automobile is in a forward running state.

It can be understood that, when the electric vehicle is in a driving state, the electric vehicle can move forward or backward, and different driving states can be switched by switching gears, so as to ensure that the electric vehicle can reliably control and process the fault further when the electric vehicle has a serious fault, the electric vehicle needs to be in the forward driving state, so as to avoid causing safety accidents.

S604, acquiring a first external instruction signal, and judging whether the first external instruction signal is consistent with a first preset signal. If the first external command signal is consistent with the first preset signal, step S605 is executed, and if the first external command signal is not consistent with the first preset signal, step S606 is executed.

And S605, controlling the electric automobile to enter a first working state, wherein the first working state comprises a limp-home working state.

And S606, controlling the electric automobile to enter a second working state, wherein the second working state comprises the zero clearing of the motor torque.

In the embodiment, a fault trigger signal is obtained, a first fault type is determined through analysis according to the fault trigger signal, then the first fault type is compared with a preset fault type, whether the electric automobile is in a forward running state at the moment is further determined, when the electric automobile is determined to be in the forward running state, the electric automobile is controlled to enter a first working state and immediately enter a limp working state through obtaining a first external signal when the first external command signal is determined to be consistent with the first preset signal, so that the electric automobile slowly runs to a safety zone, if the first external command signal is inconsistent with the first preset signal, the electric automobile is controlled to enter a second working state, and the output torque of a motor in the electric automobile is cleared, and safety accidents are avoided. Therefore, different control operations are carried out according to the first external signal, the electric automobile is guaranteed to have certain controllability for fault treatment when serious faults occur, and the safety and the intelligence of the electric automobile are improved.

After the output torque of the motor in the electric vehicle is set to zero, the electric vehicle may be powered down by an external command signal (for example, a start button of the vehicle is turned OFF or a start key is turned to an OFF gear), so that a driver may further troubleshoot the electric vehicle and the safety of the electric vehicle is improved.

Optionally, fig. 7 is a flowchart of a control method of another electric vehicle according to an embodiment of the present invention, and as shown in fig. 7, on the basis of fig. 1, the preset fault type includes a charge interlock fault, and the second operating state includes motor torque zero clearing. Therefore, the control method includes the steps of:

s701, acquiring a fault trigger signal, and analyzing according to the fault trigger signal to determine a first fault type.

S702, comparing the first fault type with a preset fault type, and determining that the first fault type is the preset fault type.

Specifically, the preset fault type includes a charging interlock fault, and it can be understood that, in a normal charging state of the electric vehicle, the electric vehicle may simultaneously satisfy the conditions that the charging gun is in a connection state, the charging mode is configured as direct current charging or alternating current charging, and an electric wake-up signal is detected, but if at least one of the three conditions is not satisfied, it is indicated that the charging interlock fault occurs in the electric vehicle.

And S703, judging that the electric automobile is in a driving permission state.

It can be understood that after the electric vehicle is powered on at high voltage, the electric vehicle is in a driving-permitted state, and at this time, the electric vehicle may be in a driving process or a temporary stop state, which is not limited in real time by the present invention.

S704, acquiring a first external instruction signal, and judging whether the first external instruction signal is consistent with a first preset signal. If the first external command signal is consistent with the first preset signal, step S605 is executed, and if the first external command signal is not consistent with the first preset signal, step S606 is executed.

S705, controlling the electric automobile to enter a first working state, wherein the first working state comprises a limp-home working state.

And S706, controlling the electric automobile to enter a second working state, wherein the second working state comprises the step of clearing the motor torque.

In the embodiment, a fault trigger signal is obtained, a first fault type is determined through analysis according to the fault trigger signal, then the first fault type is compared with a preset fault type, when the first fault type is determined to be a charging interlocking fault in the preset fault type, whether the electric automobile is in a driving permission state at the moment is further determined, and when the electric automobile is determined to be in the driving permission state, the electric automobile is controlled to enter a first working state and immediately enter a limp working state through obtaining a first external signal when the first external command signal is determined to be consistent with the first preset signal, so that the electric automobile slowly drives to a safety zone, if the first external command signal is inconsistent with the first preset signal, the electric automobile is controlled to enter a second working state, and the output torque of a motor in the electric automobile is cleared, and safety accidents are avoided. Therefore, different control operations are carried out according to the first external signal, the electric automobile is guaranteed to have certain controllability for fault treatment when serious faults occur, and the safety and the intelligence of the electric automobile are improved.

After the output torque of the motor in the electric vehicle is set to zero, the electric vehicle may be powered down by an external command signal (for example, a start button of the vehicle is turned OFF or a start key is turned to an OFF gear), so that a driver may further troubleshoot the electric vehicle and the safety of the electric vehicle is improved. Optionally, fig. 8 is a flowchart of a control method of another electric vehicle according to an embodiment of the present invention, as shown in fig. 8, before acquiring the first external command signal and determining whether the first external command signal is consistent with the first preset signal on the basis of fig. 1, the method further includes: recording the occurrence frequency of the first fault type and recording as a first numerical value; judging whether the first value is smaller than or equal to a preset threshold value; if the first value is smaller than or equal to the preset threshold value, continuously acquiring a first external instruction signal, and judging whether the first external instruction signal is consistent with a first preset signal or not; and if the first value is larger than the preset threshold value, controlling the electric automobile to enter a second working state, wherein the second working state comprises high-voltage reduction or motor torque zero clearing.

Therefore, the control method specifically comprises the following steps:

s801, acquiring a fault trigger signal, and analyzing according to the fault trigger signal to determine a first fault type.

S802, comparing the first fault type with a preset fault type, and determining that the first fault type is the preset fault type.

And S803, recording the occurrence frequency of the first fault type and recording the occurrence frequency as a first numerical value.

Specifically, since the fault type generally refers to a relatively serious fault in the electric vehicle, considering the safety of the electric vehicle, the first fault type is a preset fault type which cannot be continuously generated for many times, and thus a safety accident will be caused. Therefore, after the electric vehicle finishes powering on the vehicle control unit, the vehicle control unit counts the number of times according to the determined first fault type. It should be noted that, when the electric vehicle does not have any fault, the first value is cleared, so as to avoid influencing the control after the next charging and powering on.

S804, determining whether the first value is less than or equal to a preset threshold, if the first value is less than or equal to the preset threshold, executing step S805, and if the first value is greater than the preset threshold, executing step S807.

The specific value of the preset threshold may be set according to actual conditions, for example, the preset threshold is 3.

S805, acquiring the first external instruction signal, and judging whether the first external instruction signal is consistent with the first preset signal. If the first external command signal is consistent with the first preset signal, step S806 is executed, and if the first external command signal is not consistent with the first preset signal, step S807 is executed.

And S806, controlling the electric automobile to enter a first working state, wherein the first working state comprises a limp-home working state.

And S807, controlling the electric automobile to enter a second working state, wherein the second working state comprises high-voltage reduction or motor torque zero clearing.

In this embodiment, when the fault that the electric automobile takes place satisfies the default fault type, need count the number of times that the first fault type takes place, and note first numerical value, if first numerical value is less than or equal to the default threshold value, can continue through obtaining first outside command signal, and when first command signal is unanimous with first default signal, control vehicle can enter into limp operating condition, allow the driver to go the car to comparatively safe position, make things convenient for follow-up vehicle maintenance, reduced to a certain extent after the fault takes place the risk that the traffic accident takes place at danger area forced clear torsion and high voltage reduction. Conversely, if the first value is larger than the preset threshold value, the output torque of the motor of the electric automobile is forcibly controlled to be reduced to zero or the high-voltage circuit is disconnected. So, take place to prescribe a limit to this moment through the trouble to electric automobile, can further guarantee when taking place serious failure, still can carry out selective control to electric automobile's operating condition for electric automobile has certain controllability to the fault handling when taking place serious failure, improves electric automobile's security and intellectuality.

It should be noted that, in another embodiment, the switching between the first operating state and the second operating state may also be performed directly according to the occurrence number of the first fault type, without determining whether the first external instruction signal is consistent with the first preset signal. In other words, if the first value is less than or equal to the preset threshold, the electric vehicle is controlled to enter a first working state, and the first working state comprises a limp-home working state; and if the first value is larger than the preset threshold value, controlling the electric automobile to enter a second working state, wherein the second working state comprises high-voltage reduction or motor torque zero clearing. Therefore, the working state of the electric automobile can be selectively controlled only by comparing the occurrence frequency of the first fault type with the preset threshold value, so that the electric automobile has certain controllability on fault treatment when serious faults occur, and the safety and the intelligence of the electric automobile are improved.

Optionally, fig. 9 is a flowchart of a control method of an electric vehicle according to another embodiment of the present invention, as shown in fig. 9, and on the basis of fig. 1, if the first external command signal is consistent with the first preset signal, after the electric vehicle is controlled to enter the first operating state, where the first operating state includes a limp home operating state, the method includes: controlling the speed of the electric automobile to be a first target speed, and controlling the running power of a motor in the electric automobile to be a first target power. Therefore, the control method mainly comprises the following steps:

s901, acquiring a fault trigger signal, and analyzing according to the fault trigger signal to determine a first fault type.

S902, comparing the first fault type with a preset fault type, and determining that the first fault type is the preset fault type.

S903, acquiring the first external instruction signal, and judging whether the first external instruction signal is consistent with the first preset signal. If the first external command signal is consistent with the first preset signal, step S904 is performed, and if the first external command signal is inconsistent with the first preset signal, step S906 is performed.

And S904, controlling the electric automobile to enter a first working state, wherein the first working state comprises a limp-home working state.

S905, controlling the speed of the electric automobile to be a first target speed, and controlling the running power of a motor in the electric automobile to be a first target power.

The specific magnitude of the first target vehicle speed is not limited in the embodiments of the present invention, and is, for example, 20 km/h. It is understood that different types of motors of electric vehicles and rated powers of the motors may also differ, and therefore, the first target power may be defined according to the magnitude of the rated operating power of the motors, for example, the first target power is 30% of the rated operating power of the motors.

And S906, controlling the electric automobile to enter a second working state, wherein the second working state comprises high-voltage reduction or motor torque zero clearing.

In this embodiment, when the electric vehicle is consistent with the first preset signal according to the acquired first external instruction, at this time, the electric vehicle may enter a limp working state, that is, limit speed and power of the electric vehicle, allow a driver to drive to a safe zone at a low speed, facilitate subsequent vehicle maintenance, and reduce risks such as forced torque clearing in a dangerous zone and traffic accidents at a low voltage after a fault occurs to a certain extent. Meanwhile, icons are displayed on corresponding faults through an instrument panel in the electric automobile, and a driver is reminded of the existence of the faults in the current automobile at any time and needs to drive carefully.

It should be noted that, in any of the above embodiments, once the electric vehicle enters the limp home operating state, if the fault indication icon on the instrument panel in the electric vehicle disappears, the electric vehicle is still in the limp home operating state, and does not suddenly exit the limp home operating state due to the disappearance of the fault, so as to improve the safety of the electric vehicle. However, if the electric vehicle enters the limp home operating state, the first external instruction signal is continuously acquired in real time, and if the first external instruction signal is no longer consistent with the first preset signal at this time, the electric vehicle is controlled to exit the limp home operating state and directly enters the second operating state under the condition that the fault still exists.

Based on the same inventive concept, an embodiment of the present invention further provides a control system of an electric vehicle, fig. 10 is a schematic structural diagram of the control system of the electric vehicle provided in the embodiment of the present invention, as shown in fig. 10, the electric vehicle includes a vehicle controller 10, and the vehicle controller 10 is used in the control method of the electric vehicle in any of the embodiments.

Optionally, with continued reference to fig. 10, the electric vehicle further includes a battery management module 20, a brake pedal control module 30 and a motor control module 40 electrically connected to the vehicle controller 10, respectively; the battery management module 20 is used for providing a high-voltage electric signal for the electric automobile; the brake pedal control module 30 is used for braking the electric vehicle; the motor control module 40 is used for driving the electric automobile to run.

Specifically, the battery management module 20 is further electrically connected to the motor control module 40, and the battery management module 20 includes a power battery and provides a high-voltage electrical signal for the motor control module 40, so as to realize pre-charging and stable operation of the motor control module 40. The vehicle control unit 10 is capable of receiving and recognizing various electric signals and fault signals from the battery management module 20, the brake pedal control module 30 and the motor control module 40, and also recognizing the operation of the driver, and sending a control command to the motor control module 40 through further processing and analysis, so that the motor control module 40 drives the electric vehicle to run, or sending a control command to the brake pedal control module 30, so that the brake pedal control module 30 performs a braking operation on the electric vehicle.

Further, when the vehicle control unit 10 receives the fault signal from the battery management module 20, the brake pedal control module 30, or the motor control module 40 and determines that the corresponding fault type is consistent with the preset fault type, the vehicle control unit further obtains a first external instruction signal (for example, a signal triggered by a manual operation of a driver), and when it determines that the first external instruction signal is consistent with the first preset signal, sends a corresponding instruction signal to the motor control module 40, so that the motor control module 40 controls the electric vehicle to enter a limp working state, and the electric vehicle slowly travels to a safe zone. If the vehicle control unit 10 determines that the first external command signal is inconsistent with the first preset signal, the vehicle control unit sends a corresponding command signal to the battery management module 20, disconnects the high-voltage power supply path, and performs forced high-voltage power-off operation, thereby avoiding safety accidents. Therefore, the working state of the electric automobile can still be selectively controlled when a serious fault occurs, so that the electric automobile has certain controllability on fault treatment when the serious fault occurs, and the safety and the intelligence of the electric automobile are improved.

In addition, the control system of the electric vehicle further includes a meter 50 for displaying the determined fault type of the whole vehicle and the current operating state (limp-home operating state or high-voltage-low state), the vehicle speed, the motor power and other parameters of the electric vehicle in real time.

The above-described embodiments should not be construed as limiting the scope of the invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions may be made in accordance with design requirements and other factors. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A control method of an electric vehicle, characterized by comprising:

acquiring a fault trigger signal, and analyzing according to the fault trigger signal to determine a first fault type;

and if the first external command signal is inconsistent with the first preset signal, controlling the electric automobile to enter a second working state, wherein the second working state comprises high-voltage reduction or motor torque zero clearing.

2. The control method of an electric vehicle according to claim 1, wherein the preset fault type includes a high-voltage interlock fault, and the second operating state includes a high-voltage pull-down;

before acquiring a first external instruction signal and judging whether the first external instruction signal is consistent with a first preset signal, the method comprises the following steps:

judging whether the electric automobile is powered on at high voltage or not;

if the electric automobile does not finish high-voltage electrification, controlling the electric automobile to forbid high-voltage electrification operation;

and if the electric automobile is electrified at high voltage, continuously acquiring a first external instruction signal, and judging whether the first external instruction signal is consistent with a first preset signal.

3. The method for controlling an electric vehicle according to claim 2, wherein if the electric vehicle does not complete high voltage power-on, after controlling the electric vehicle to prohibit a high voltage power-on operation, further comprising:

if the first external instruction signal is consistent with a first preset signal, controlling the electric automobile to enter a third working state, wherein the third working state comprises high-voltage power-on operation and early warning prompt, and after the electric automobile is judged to be powered on at high voltage, controlling the electric automobile to enter a first working state, and the first working state comprises a limp working state;

and if the first external instruction signal is inconsistent with a first preset signal, controlling the electric automobile to forbid high-voltage electrifying operation.

4. The method for controlling an electric vehicle according to claim 2, wherein if the electric vehicle has completed high voltage power-up and the first external command signal is consistent with a first preset signal, before controlling the electric vehicle to enter a first operating state, the first operating state comprising a limp home operating state, further comprising:

and judging that the electric automobile has driving conditions, wherein the driving conditions comprise that a motor control loop of the electric automobile completes pre-charging.

5. The method for controlling an electric vehicle according to any one of claims 3 or 4, wherein if the first external command signal is inconsistent with a first preset signal, before controlling the electric vehicle to enter a second operating state, the second operating state including a high-voltage step-down, the method comprises:

controlling the output torque of a motor in the electric automobile to be zero;

the method comprises the steps of obtaining the speed of the electric automobile, and controlling the electric automobile to enter a second working state when the speed of the electric automobile is judged to be smaller than a preset speed threshold value, wherein the second working state comprises a high-voltage low-voltage state.

6. The control method of the electric vehicle according to claim 1, wherein the preset fault type includes a brake pedal sensor fault, and the second operating state includes a motor torque zero clearing;

and judging that the electric automobile is in a forward driving state.

7. The control method of the electric vehicle according to claim 1, wherein the preset fault type includes a charge interlock fault, and the second operating state includes a motor torque zero clearing;

and judging that the electric automobile is in a driving permission state.

8. The method for controlling an electric vehicle according to claim 1, further comprising, before acquiring a first external command signal and determining whether the first external command signal matches a first preset signal:

recording the occurrence frequency of the first fault type and recording as a first numerical value;

judging whether the first numerical value is smaller than or equal to a preset threshold value;

if the first value is smaller than or equal to the preset threshold, continuously acquiring a first external instruction signal, and judging whether the first external instruction signal is consistent with a first preset signal;

and if the first value is larger than the preset threshold value, controlling the electric automobile to enter a second working state, wherein the second working state comprises high-voltage reduction or motor torque zero clearing.

9. The method for controlling an electric vehicle according to claim 1, wherein if the first external command signal coincides with a first preset signal, after controlling the electric vehicle to enter a first operating state including a limp home operating state, comprising:

controlling the speed of the electric automobile to be a first target speed, and controlling the running power of a motor in the electric automobile to be a first target power.

10. A control system of an electric vehicle, the electric vehicle comprising a vehicle controller configured to execute the control method of the electric vehicle according to any one of claims 1 to 9.

11. The control system of the electric vehicle according to claim 10, further comprising a battery management module, a brake pedal control module and a motor control module electrically connected to the vehicle control unit, respectively;

the battery management module is used for providing a high-voltage electric signal for the electric automobile;

the brake pedal control module is used for braking the electric automobile;

the motor control module is used for driving the electric automobile to run.