CN112721648A - Electric vehicle sliding control method, storage medium and system - Google Patents
Electric vehicle sliding control method, storage medium and system Download PDFInfo
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
- B60L7/00—Electrodynamic brake systems for vehicles in general
- B60L7/10—Dynamic electric regenerative braking
- B60L7/18—Controlling the braking effect
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
- B60T13/74—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with electrical assistance or drive
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
- B60T13/74—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with electrical assistance or drive
- B60T13/745—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with electrical assistance or drive acting on a hydraulic system, e.g. a master cylinder
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Abstract
The application provides a method, a storage medium and a system for controlling sliding of an electric automobile, wherein the method comprises the following steps: responding to a running state signal of the automobile entering a sliding working condition, and acquiring a preset sliding recovery grade and the current running speed of the automobile; determining the target deceleration of the automobile according to the current running speed and the preset sliding recovery level; obtaining the target braking force of the automobile according to the current running speed and the target deceleration; distributing the target braking force into a target electric braking force and a target hydraulic braking force; and acquiring the actual deceleration of the automobile under the target braking force, and compensating the target braking force according to the actual deceleration and the target deceleration to obtain the compensated target braking force. According to the scheme, the closed-loop control scheme that the target deceleration is used as the control target under the coasting working condition of the vehicle is realized, and the deceleration of the vehicle can reach the real target deceleration.
Description
Technical Field
The application belongs to the technical field of new energy automobiles, and particularly relates to a sliding control method, a storage medium and a system of an electric automobile.
Background
The electric automobile can realize energy recovery through motor braking when the automobile slides, thereby improving the endurance mileage and reducing the energy consumption, and is an advantageous item compared with a fuel automobile. When a driver releases an accelerator to slide and decelerate, the electric automobile on the market basically decelerates by recovering torque by the driving motor in a medium and high speed range, so that energy recovery is realized. The recovery torque executed by the driving motor is generally calculated according to the current actual vehicle speed, the sliding recovery strength set by a driver and the gradient when the vehicle runs on a ramp road to obtain the recovery torque executable by the driving motor, so that electric energy recovery to a certain degree is realized. The deceleration recovery mode has the following defects:
the recovery capability of the electric braking mode is limited by the recovery capability of the power battery and the capability of the driving motor to execute torque recovery, and particularly when the power battery is high in electric quantity and is at an extreme working temperature or the power battery and the driving motor are in failure, the recovery capability is basically not available or lost. Such a situation may cause the deceleration of the vehicle to be less than the same deceleration performance as that in the normal driving when the driver releases the accelerator pedal, and thus may cause a safety hazard.
Therefore, the sliding energy recovery method of the existing electric automobile still has a certain lifting space.
Disclosure of Invention
The application aims to provide a method, a storage medium and a system for controlling sliding of an electric automobile, which are used for solving the technical problem that deceleration cannot meet the deceleration requirement in the sliding braking process in the prior art.
To this end, some embodiments of the present application provide a method for controlling coasting of an electric vehicle, including:
responding to a running state signal of the automobile entering a sliding working condition, and acquiring a preset sliding recovery grade and the current running speed of the automobile;
determining the target deceleration of the automobile according to the current running speed and the preset sliding recovery level;
obtaining a target braking force of the automobile according to the current running speed and the target deceleration;
distributing the target braking force into a target electric braking force and a target hydraulic braking force;
and acquiring the actual deceleration of the automobile under the target braking force, and compensating the target braking force according to the actual deceleration and the target deceleration to obtain the compensated target braking force.
In some embodiments of the electric vehicle coasting control method of the present application, the step of distributing the target braking force into the target electric braking force and the target hydraulic braking force includes:
acquiring chargeable power of a battery and accessory consumed power;
obtaining the target electric braking force according to the chargeable power and the accessory consumed power;
and obtaining the target hydraulic braking force according to the target braking force and the target electric braking force.
In some embodiments of the present application, the step of obtaining the target electric braking force according to the chargeable power and the accessory consumption power includes:
deriving a total recoverable power P from a sum of said chargeable power and said accessory consumed powerall；
Obtaining the target electric braking force T of the motor according to the following formulaqavl：
Tqavl＝min(Tq1，Tq2)；
Wherein A, B and C are calibration coefficients, R is the tire radius, V is the current driving speed, and T is the current driving speedq1For calculating the available braking force based on the total recoverable power, Tq2For the current executable braking force of the electric machine, TqavlIs Tq1And Tq2The smaller of these.
In some embodiments of the electric vehicle coasting control method of the present application, the step of distributing the target braking force into the target electric braking force and the target hydraulic braking force further includes:
determining a compensation braking force according to the target electric braking force and the actual electric braking force;
and compensating the target hydraulic braking force according to the compensating braking force.
In some embodiments of the present application, the step of determining the target deceleration of the vehicle according to the current driving speed and the preset coasting recovery level includes:
determining a target deceleration upper limit value according to the gravity deceleration and the deceleration maximum compensation amount;
obtaining an initial target deceleration according to the current running speed and the preset sliding recovery grade;
if the initial target deceleration is less than or equal to the target deceleration upper limit value, taking the initial target deceleration as the target deceleration; if the initial target deceleration is greater than the target deceleration upper limit value, taking the target deceleration upper limit value as the target deceleration;
the deceleration maximum compensation amount refers to: the maximum deceleration compensation amount that the hydraulic braking force can provide when the deceleration is reduced due to the loss of the electric braking force.
In some embodiments of the present application, the step of determining the target deceleration of the vehicle according to the current driving speed and the preset coasting recovery level includes:
determining a base deceleration of the automobile according to the current running speed;
and determining a correction coefficient according to the preset sliding recovery grade, and correcting the basic deceleration by using the correction coefficient to obtain the target deceleration.
In some embodiments of the present application, in the electric vehicle coasting control method, a correction coefficient is determined according to the preset coasting recovery level, and the step of correcting the base deceleration by using the correction coefficient to obtain the target deceleration comprises:
the preset sliding recovery grade at least comprises a first grade, a second grade and a third grade, the basic decelerations corresponding to the first grade, the second grade and the third grade are sequentially increased, and the correction coefficients corresponding to the first grade, the second grade and the third grade are sequentially increased.
In some embodiments of the present application, the method for controlling coasting of an electric vehicle, wherein compensating the target braking force according to the actual deceleration and the target deceleration to obtain a compensated target braking force comprises:
fveh＝fb+p*(aveh-aact)；
wherein f isvehFor the compensated target braking force, fbFor the target braking force, aactFor said actual deceleration, avehFor the target deceleration, p is a proportional compensation factor.
Some embodiments of the present application further provide a storage medium, where the storage medium stores program instructions, and a computer reads the program instructions and executes the electric vehicle coasting control method described in any one of the above.
Some embodiments of the present application further provide an electric vehicle coasting control system, which includes at least one processor and at least one memory, at least one of the memories storing program instructions, and at least one of the processors executing the electric vehicle coasting control method described in any of the above items after reading the program instructions.
Compared with the prior art, the above technical scheme provided by the application has the following beneficial effects at least: after the automobile enters a coasting working condition, a target deceleration is determined according to a coasting recovery level set by a user and the current running speed of the automobile, a target braking force is determined according to the target deceleration, the target braking force is distributed into a target electric braking force and a target hydraulic braking force, in order to prevent the electric braking force from being influenced by a use environment and not reaching the target value, the target braking force is continuously compensated according to the relation between the actual deceleration and the target deceleration of the automobile, and the compensated target value power can really meet the braking requirement, so that the deceleration of the automobile can reach the real target deceleration.
Drawings
FIG. 1 is a flowchart illustrating a coasting control method for an electric vehicle according to an embodiment of the present application;
FIG. 2 is a flowchart illustrating coordinated control of a target braking force and a hydraulic braking force in a coasting control method of an electric vehicle according to an embodiment of the present application;
fig. 3 is a block diagram of an electric vehicle coasting control system according to an embodiment of the present application.
Detailed Description
The embodiments of the present application will be further described with reference to the accompanying drawings. In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description of the present application, and do not indicate or imply that the device or component being referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Wherein the terms "first position" and "second position" are two different positions.
Some embodiments of the present application provide a method for controlling sliding of an electric vehicle, which may be applied to a unit having a control function on a vehicle, as shown in fig. 1, and may include:
s101: and responding to a running state signal of the automobile entering the sliding working condition, and acquiring a preset sliding recovery grade and the current running speed of the automobile. The vehicle is provided with a plurality of sensors for detecting the running state of the vehicle, and the vehicle-mounted control unit receives detection signals of the sensors and determines whether the vehicle enters the sliding working condition or not according to the detection signals of each sensor. Specifically, if the accelerator pedal depression angle detected by an accelerator pedal angle detection sensor provided on the accelerator pedal is zero (i.e., a completely released state), the brake pedal depression angle detected by a brake pedal angle detection sensor provided on the brake pedal is zero (indicating that the brake pedal is not depressed), and the shift lever position detected by a shift lever position detection sensor provided on the shift lever indicates that the vehicle is in a drivable gear (i.e., the shift lever is in a D-gear or an R-gear), it may be determined that the vehicle enters a coasting state, and the sum of the driving states may constitute a driving state signal that the vehicle enters the coasting state. The preset coasting recovery level is a level value preset by a driver, the level value can reflect the deceleration performance requirement of the driver for the vehicle during the sliding process, if the driver wants the deceleration performance to be stronger, the level value can be set to be higher, and if the driver wants the deceleration performance to be more gradual, the level value can be set to be lower.
S102: and determining the target deceleration of the automobile according to the current running speed and the preset coasting recovery level. In this step, first, a base deceleration may be determined based on the current running speed. The base deceleration is obtained at the current running speed according to a vehicle speed-deceleration correspondence relationship stored in advance in the in-vehicle control unit. This base deceleration is positively correlated with the magnitude of the current running speed, and decreases as the current running speed decreases. In order to ensure that the vehicle decelerates stably at each vehicle speed, the basic deceleration at each vehicle speed can be tested for multiple times according to the concrete deceleration performance of the real vehicle to obtain a group of optimal data, and the optimal data after the test is stored in the vehicle-mounted control unit to serve as the corresponding relation between the vehicle speed and the deceleration. Next, as described above, different drivers experience different demands for the vehicle deceleration, and some drivers may desire more intense deceleration and some drivers may desire more gradual deceleration. In some embodiments, the preset coasting recovery level includes at least a first level, a second level, and a third level, and the base decelerations corresponding to the first level, the second level, and the third level are sequentially increased, and the correction coefficients corresponding to the first level, the second level, and the third level are sequentially increased. In order to enrich the driving experience of the driver, the preset coasting recovery level may include other levels, such as only two levels or four, five levels, etc. In this embodiment, in order to meet the coasting recovery strength requirement set by the driver, the preset coasting recovery level is represented by a correction coefficient, and the correction coefficient may be used to represent a more intense or more gradual deceleration experience required by the driver with respect to the basic deceleration performance. The corrected base deceleration is the target deceleration, and the relationship therebetween can be expressed as follows.
aveh＝abasic*i；
In the above formula, avehFor a target deceleration, abasicI is a correction coefficient, which is equal to or greater than 0, for the base deceleration. The correction factor is related to the preset coasting recovery level set by the driver, and as an implementation manner, the relationship between the correction factor and the preset coasting recovery level can be represented by the following table. In table 1, the preset coasting recovery levels may include three levels of weak, medium, and strong. The selection of the correction coefficient is only one implementation mode, and calibration optimization can be carried out along with the performance of the deceleration intensity of the vehicle in practical application.
TABLE 1 relationship of correction factor to preset glide recovery level
S103: and obtaining the target braking force of the automobile according to the current running speed and the target deceleration. Theoretically, the target braking force can ensure the requirement of the target deceleration achieved when the automobile decelerates in a flat road surface sliding way, and the target braking force can be calculated according to the following formula:
fb＝aveh*m；
wherein f isbA target braking force (which can be set according to different driving road conditions, and can be selected to be the target braking force during level road sliding or the target braking force during slope road sliding, for example)vehFor the target deceleration, m is the vehicle load weight.
S104: the target braking force is distributed into a target electric braking force and a target hydraulic braking force. During braking, the braking force may come from the electric motor and the chassis hydraulics, thus dividing the target braking force into both electric and hydraulic braking forces. The electric braking force can be set according to the maximum braking capacity which can be executed by the motor, and the hydraulic braking force can be directly obtained by subtracting part of the electric braking force from the target braking force.
S105: and acquiring the actual deceleration of the automobile under the target braking force, and compensating the target braking force according to the actual deceleration and the target deceleration to obtain the compensated target braking force. Although the target electric braking force can reach the maximum braking capability of the motor in theory, in actual implementation, the braking force actually executed by the vehicle is likely not to reach the maximum target electric braking force according to the influence of the vehicle running road condition, the ambient temperature and the like, which results in that the actual deceleration represented by the vehicle does not necessarily reach the target deceleration. Therefore, the target braking force is compensated according to the actual deceleration and the target deceleration, so that the actually obtained target braking force can meet the requirement of the target deceleration.
According to the scheme in the embodiment of the application, after the automobile enters the coasting working condition, the target deceleration is determined according to the coasting recovery level set by the user and the current running speed of the automobile, the target braking force is determined according to the target deceleration, the target braking force is distributed into the target electric braking force and the target hydraulic braking force, in order to prevent the electric braking force from being influenced by the use environment and not reaching the target value, the target braking force is continuously compensated according to the relation between the actual deceleration and the target deceleration of the automobile, and the compensated target value power can really meet the braking requirement, so that the deceleration of the automobile can reach the real target deceleration.
In some embodiments, in order to ensure that the vehicles can have the same deceleration performance under different power battery capacities and operating temperatures, and at the same time, the maximum electric energy recovery can be ensured, as shown in fig. 2, the coordinated control of the electric braking force and the hydraulic braking force, that is, the specific implementation process of step S104, may include:
s401: the chargeable power of the battery and the accessory consumption power are acquired. The electric braking force of the motor is the recoverable torque of the motor, the recoverable torque of the motor needs to determine recoverable power, and the recoverable power is closely related to the chargeable power of the battery and the accessory consumed power, so that the recoverable power of the battery is extracted from the battery monitoring result of the battery management system, the accessory consumed power running on the vehicle is detected through the vehicle-mounted control unit, and the accessory consumed power is calculated. The chargeable power is the power difference between the power at which the battery is in a full state and the current power.
S402: the target electric braking force is obtained according to the chargeable power and the accessory consumed power. Specifically, the method comprises the following steps: deriving a total recoverable power P from a sum of said chargeable power and said accessory consumed powerallCan be directly obtained by adding the two; obtaining the target electric braking force T of the motor according to the following formulaqavl：
Tqavl＝min(Tq1，Tq2)；
Wherein A, B and C are calibration coefficients, R is the tire radius, V is the current driving speed, and T is the current driving speedq1For calculating the available braking force based on the total recoverable power, Tq2For braking force corresponding to target deceleration, TqavlIs Tq1And Tq2The smaller of these. The calibration coefficients a, B and C may be determined according to the actual vehicle conditions and deceleration performance, for example, a may be selected from 9000-; b may be selected between 3 and 5, such as B ═ 3.6; c may be selected between 50-80, such as C60. In practice, the values of A, B and C may be nominally modified. That is, if the braking force provided by the motor itself can already satisfy the demand of the target deceleration, the braking force corresponding to the target deceleration may be directly used as the target electric braking force of the motor, otherwise, the braking force corresponding to the total recoverable power of the motor is required as the target electric braking force.
And S403, obtaining the target hydraulic braking force according to the target braking force and the target electric braking force. And directly subtracting the target electric braking force from the target braking force to obtain the target hydraulic braking force.
In some embodiments, the above distribution method can match the motor and the hydraulic brake to meet the deceleration requirement, but in reality, the motor may not be able to execute the determined target electric braking force due to various reasons, such as too low ambient temperature, low battery level, and the like, in this case, the electric braking force is compensated in some embodiments of the present application by the following steps:
and S404, acquiring the actual electric braking force of the motor. The actual recovery torque can be directly obtained as the electric braking force according to the motor controller configured by the motor.
And S405, determining a compensation braking force according to the target electric braking force and the actual electric braking force. The difference value obtained by subtracting the actual electric braking force from the target electric braking force can be directly used as the compensation braking force.
And S406, compensating the target hydraulic braking force according to the compensation braking force. The compensation can be made directly by adding the compensation braking force to the original hydraulic target braking force.
Through the scheme, the braking force lost by the motor is compensated through hydraulic braking, so that the actually obtained total braking force can still reach the target braking force.
In some embodiments, the target deceleration upper limit value may be determined from the gravity deceleration and the deceleration maximum compensation amount; an initial target deceleration is obtained according to the current running speed and the preset coasting recovery level (the calculation step may refer to the process described in step S102, and will not be described in detail herein); if the initial target deceleration is less than or equal to the target deceleration upper limit value, taking the initial target deceleration as the target deceleration; if the initial target deceleration is greater than the target deceleration upper limit value, taking the target deceleration upper limit value as the target deceleration; the deceleration maximum compensation amount refers to: when deceleration is reduced due to loss of electric braking force, hydraulic braking force can be usedThe maximum deceleration compensation provided. For example: the target deceleration of the motor cannot be larger than nxg, g is gravity deceleration and is constant 9.8m/s2And n is a deceleration maximum compensation amount, i.e., the ability to cause a deceleration decrease according to the chassis being able to maximally compensate for electric braking loss. The target deceleration cannot exceed the value, and thus, potential safety hazards caused by the fact that the hydraulic brakes are all used for compensating the loss of the electric brake deceleration when the electric system recovery capacity is lost or the electric system energy recovery fails are avoided. On this basis, the deceleration that the target braking force can achieve should be less than or equal to nxg. Thus, the target electric braking force and the target hydraulic braking force can be determined according to the following three conditions:
(1) the target deceleration being less than or equal to nxg, i.e. avehWhen the ratio is less than or equal to nxg:
the target braking force is calculated according to the procedure described in step S102. If the target braking force is less than or equal to the maximum torque that the electric system can recover (i.e., less than or equal to the maximum braking force T that the electric machine can execute)max) The total target braking force may be all allocated as the target electric braking force, and the target hydraulic braking force may be set to 0; if the target braking force is larger than the maximum torque that can be recovered by the electric system (i.e., larger than the maximum braking force T that can be executed by the motor), the target braking force is set to be larger than the maximum torque that can be recovered by the electric systemmax) At the maximum braking force T that the motor can performmaxAs the target electric braking force, the target hydraulic braking force is the target braking force minus the maximum braking force T that the motor can performmaxThe calculation formula is obtained as follows:
if fb≤TmaxThen f ismotor＝fb，fhy＝0；
If fb＞TmaxThen f ismotor＝Tmax，fhy＝fb-fmax。
Wherein f ismotorFor the target electric braking force, fhyThe target hydraulic braking force is obtained.
(2) The target deceleration being greater than nxg, i.e. avehAt > n × g:
at this time, the target should be reducedThe speed is adjusted to be nxg; the target braking force should be a braking force T corresponding to n × g decelerationng. If so, TngLess than or equal to the maximum torque that the electric system can recover, the total target braking force may be all allocated as the target electric braking force, and the target hydraulic braking force may be set to 0; if so, TngGreater than the maximum torque that the electric system can recover, with the maximum braking force T that the electric machine can performmaxAs a target electric braking force, the target hydraulic braking force is TngMinus the maximum braking force T that the motor can performmaxThe calculation formula is obtained as follows:
if Tng≤TmaxThen f ismotor＝Tng，fhy＝0；
If Tng＞TmaxThen f ismotor＝Tmax，fhy＝Tng-Tmax。
The target electric braking force f calculated through the above processmotorCan be directly sent to the motor to execute and read the real-time execution recovery torque f of the motor in real timemotoract. If the motor executes the recovery torque f in real timemotoractEqual to the target electric braking force f within a reasonable error rangemotorThen, the compensation of the hydraulic brake is not necessary, and the compensation electromotive force is zero. If the motor executes the recovery torque f in real time due to various unexpected factors such as the rise of the battery electric quantity, the change of the battery temperature, the failure of the motor torque response or the failure of the motor to respond to the recovery torquemotoractLess than target electric braking force fmotorAnd the difference value of the two exceeds a reasonable error range, then: the actual magnitude of the target electric braking force has already been fmotorThe value is adjusted to fmotoractIt is worth noting that in this case the target hydraulic braking force is correspondingly increased by an amount that should satisfy fmotor-fmotoractThe size of (2). Thus, the total target braking force can meet the requirement, and the vehicle can finally obtain the target deceleration, and the calculation process is as follows:
fhyc＝fmotor-fmotoract；
f′hy＝fhy+fhyc；
then utilize f'hyAs new fhyTo perform the subsequent operation.
Because the process is carried out in real time, after factors influencing the actual electric braking force of the motor disappear, the actual electric braking force can meet the size requirement of the target electric braking force, and at the moment, hydraulic braking is not needed to be adopted for compensation, and the target braking force can be distributed according to the processes in (1) and (2), so that the electric energy recovery is carried out to the maximum extent, and the energy recovery utilization rate is improved.
In some embodiments, step S105 may be implemented as follows:
fveh＝fb+p×(aveh-aact)；
wherein f isvehFor the compensated target braking force, fbFor the target braking force, aactFor said actual deceleration, avehFor the target deceleration, p is a proportional compensation factor. a isactCan be acquired by a speed sensor arranged on the vehiclevehThe target deceleration is calculated, p can be obtained by a calibration test, different vehicles have different execution results when electric braking and hydraulic braking are executed, and the proportional compensation factor is determined according to the difference between the actual electric braking and hydraulic braking and the preset electric braking and hydraulic braking.
The scheme provided by the above embodiment of the application provides a control method for the vehicle sliding after the driver releases the accelerator pedal, the method mainly comprises the determination of target braking force and the coordination control of electric braking and hydraulic braking, and the method is suitable for the sliding control of the electric quantity state of each power battery at each running speed, each running road surface and each running temperature.
Some embodiments of the present application further provide a storage medium, where the storage medium stores program instructions, and after reading the program instructions, a computer executes the electric vehicle coasting control method described in the above scheme provided in any method embodiment.
Some embodiments of the present application further provide an electric vehicle coasting control system, as shown in fig. 3, including at least one processor 101 and at least one memory 102, where at least one memory 102 stores instruction information, and after at least one processor 101 reads the program instruction, the electric vehicle coasting control method according to any of the above method embodiments may be executed. The above apparatus may further include: an input device 103 and an output device 104. The processor 101, memory 102, input device 103, and output device 104 may be connected by a bus or other means. The product can execute the method provided by the embodiment of the application, and has the corresponding functional modules and beneficial effects of the execution method. For technical details that are not described in detail in this embodiment, reference may be made to the methods provided in the embodiments of the present application.
The system provided by the application can realize the recovery of the electric energy of the automobile during sliding to the maximum extent, realize the recovery of all the electric energy in a safety range and greatly improve the endurance mileage of the electric automobile; the deceleration of the electric automobile can be ensured to meet the requirements of users at the moment when the electric automobile cannot recover energy due to the fact that the power battery is fully charged, the temperature is low or the electric recovery system fails, and the like, so that the safety of the sliding deceleration is ensured; the requirement of most driving time for vehicle deceleration can be met only through the operation of sliding (only an accelerator pedal is loosened, and a brake pedal is not stepped on), the frequent back-and-forth operation of the accelerator pedal and the brake pedal can be reduced, the driving operation is liberated, and the driving safety is improved.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present application.
Claims (10)
1. A method for controlling sliding of an electric vehicle is characterized by comprising the following steps:
responding to a running state signal of the automobile entering a sliding working condition, and acquiring a preset sliding recovery grade and the current running speed of the automobile;
determining the target deceleration of the automobile according to the current running speed and the preset sliding recovery level;
obtaining a target braking force of the automobile according to the current running speed and the target deceleration;
distributing the target braking force into a target electric braking force and a target hydraulic braking force;
and acquiring the actual deceleration of the automobile under the target braking force, and compensating the target braking force according to the actual deceleration and the target deceleration to obtain the compensated target braking force.
2. The electric vehicle coasting control method of claim 1, wherein the step of distributing the target braking force into a target electric braking force and a target hydraulic braking force comprises:
acquiring chargeable power of a battery and accessory consumed power;
obtaining the target electric braking force according to the chargeable power and the accessory consumed power;
and obtaining the target hydraulic braking force according to the target braking force and the target electric braking force.
3. The electric vehicle coasting control method of claim 2, wherein the step of obtaining the target electric braking force based on the chargeable power and the accessory consumed power comprises:
deriving a total recoverable power P from a sum of said chargeable power and said accessory consumed powerall；
Obtaining the target electric braking force T of the motor according to the following formulaqavl：
Tqavl＝min(Tq1，Tq2)；
Wherein A, B and C are calibration coefficients, R is the tire radius, V is the current driving speed, and T is the current driving speedq1For calculating the available braking force based on the total recoverable power, Tq2For the current executable braking force of the electric machine, TqavlIs Tq1And Tq2The smaller of these.
4. The electric vehicle coasting control method of claim 3, wherein the step of distributing the target braking force into a target electric braking force and a target hydraulic braking force further comprises:
determining a compensation braking force according to the target electric braking force and the actual electric braking force;
and compensating the target hydraulic braking force according to the compensating braking force.
5. The electric vehicle coasting control method of claim 1, wherein the step of determining the target deceleration of the vehicle based on the current running speed and the preset coasting recovery level comprises:
determining a target deceleration upper limit value according to the gravity deceleration and the deceleration maximum compensation amount;
obtaining an initial target deceleration according to the current running speed and the preset sliding recovery grade;
if the initial target deceleration is less than or equal to the target deceleration upper limit value, taking the initial target deceleration as the target deceleration; if the initial target deceleration is greater than the target deceleration upper limit value, taking the target deceleration upper limit value as the target deceleration;
the deceleration maximum compensation amount refers to: the maximum deceleration compensation amount that the hydraulic braking force can provide when the deceleration is reduced due to the loss of the electric braking force.
6. The electric vehicle coasting control method of any one of claims 1 to 5, wherein the step of determining the target deceleration of the vehicle based on the current running speed and the preset coasting recovery level comprises:
determining a base deceleration of the automobile according to the current running speed;
and determining a correction coefficient according to the preset sliding recovery grade, and correcting the basic deceleration by using the correction coefficient to obtain the target deceleration.
7. The electric vehicle coasting control method of claim 6, wherein a correction factor is determined according to the preset coasting recovery level, and the step of correcting the base deceleration by the correction factor to obtain the target deceleration comprises:
the preset sliding recovery grade at least comprises a first grade, a second grade and a third grade, the basic decelerations corresponding to the first grade, the second grade and the third grade are sequentially increased, and the correction coefficients corresponding to the first grade, the second grade and the third grade are sequentially increased.
8. The electric vehicle coasting control method of claim 7, wherein compensating the target braking force according to the actual deceleration and the target deceleration to obtain a compensated target braking force comprises:
fveh＝fb+p*(aveh-aact)；
wherein f isvehFor the compensated target braking force, fbFor the target braking force, aactFor said actual deceleration, avehFor the target deceleration, p is a proportional compensation factor.
9. A storage medium, wherein program instructions are stored in the storage medium, and a computer reads the program instructions and executes the electric vehicle coasting control method according to any one of claims 1 to 8.
10. An electric vehicle coasting control system comprising at least one processor and at least one memory, wherein program instructions are stored in at least one of the memories, and the at least one processor reads the program instructions and executes the electric vehicle coasting control method according to any one of claims 1 to 8.
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| CN113370792A (en) * | 2021-07-06 | 2021-09-10 | 恒大新能源汽车投资控股集团有限公司 | Electric vehicle energy recovery grade setting method, storage medium and electronic equipment |
| CN113715630A (en) * | 2021-09-01 | 2021-11-30 | 东风汽车集团股份有限公司 | Control method and device for recovering sliding braking energy and storage medium |
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| CN116968705A (en) * | 2023-09-22 | 2023-10-31 | 北京车道线科技有限公司 | Motor feedback braking torque compensation method and device in composite braking and storage medium |
| CN116968705B (en) * | 2023-09-22 | 2023-12-08 | 北京车道线科技有限公司 | Motor feedback braking torque compensation method and device in composite braking and storage medium |
| CN117429269A (en) * | 2023-12-15 | 2024-01-23 | 中国第一汽车股份有限公司 | Control method for closed-loop braking energy recovery function of new energy vehicle type and vehicle |
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