CN115257395A - Electric automobile crawling control method and device - Google Patents

Electric automobile crawling control method and device Download PDF

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Publication number
CN115257395A
CN115257395A CN202110479130.8A CN202110479130A CN115257395A CN 115257395 A CN115257395 A CN 115257395A CN 202110479130 A CN202110479130 A CN 202110479130A CN 115257395 A CN115257395 A CN 115257395A
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China
Prior art keywords
vehicle
real
working condition
time
torque
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CN202110479130.8A
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Chinese (zh)
Inventor
彭君
黎润东
伊海霞
梁万武
罗经纬
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GAC Aion New Energy Automobile Co Ltd
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GAC Aion New Energy Automobile Co Ltd
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Priority to CN202110479130.8A priority Critical patent/CN115257395A/en
Publication of CN115257395A publication Critical patent/CN115257395A/en
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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
    • B60L15/00—Methods, circuits, or devices for controlling the traction-motor speed of electrically-propelled vehicles
    • B60L15/20—Methods, circuits, or devices for controlling the traction-motor speed of electrically-propelled vehicles for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed
    • B60L15/2063—Methods, circuits, or devices for controlling the traction-motor speed of electrically-propelled vehicles for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed for creeping
    • 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
    • B60L2240/00—Control parameters of input or output; Target parameters
    • B60L2240/10—Vehicle control parameters
    • B60L2240/12—Speed
    • 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
    • B60L2240/00—Control parameters of input or output; Target parameters
    • B60L2240/10—Vehicle control parameters
    • B60L2240/14—Acceleration
    • B60L2240/16—Acceleration longitudinal
    • 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
    • B60L2240/00—Control parameters of input or output; Target parameters
    • B60L2240/40—Drive Train control parameters
    • B60L2240/42—Drive Train control parameters related to electric machines
    • B60L2240/423—Torque
    • 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
    • B60L2240/00—Control parameters of input or output; Target parameters
    • B60L2240/40—Drive Train control parameters
    • B60L2240/48—Drive Train control parameters related to transmissions
    • 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
    • B60L2240/00—Control parameters of input or output; Target parameters
    • B60L2240/60—Navigation input
    • B60L2240/64—Road conditions
    • B60L2240/642—Slope of road
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/60—Other road transportation technologies with climate change mitigation effect
    • Y02T10/72—Electric energy management in electromobility

Abstract

The invention discloses a crawling control method and a crawling control device for an electric automobile, wherein the method comprises the steps of obtaining real-time crawling parameters of the automobile, wherein the real-time crawling parameters at least comprise real-time speed, target speed, gear signals, longitudinal acceleration, ramp resistance distance, ramp hill-holding torque and crawling output torque; carrying out PI regulation on the output torque of a vehicle motor according to the difference value between the real-time vehicle speed and the target vehicle speed; identifying real-time working conditions corresponding to the vehicle based on output torque, real-time vehicle speed, target vehicle speed, gear signals, longitudinal acceleration and ramp resistance distance regulated by PI; and performing preset processing on the real-time crawling parameters related to the real-time working conditions according to the real-time working conditions. The method and the device for controlling the crawling of the electric automobile can solve the problems that the vehicle slips and runs uphill, the downhill starts not smoothly and the vehicle starts to have a forward rush feeling after the brake is frequently loosened, so that the starting performance of the crawling function of the vehicle is enhanced, and the driving quality of the vehicle is improved.

Description

Electric automobile crawling control method and device
Technical Field
The invention relates to the technical field of electric vehicle control, in particular to a crawling control method and device for an electric vehicle.
Background
The electric automobile is a vehicle which uses electricity as all or part of power, accords with the road driving safety standard and drives wheels by a motor to drive, the performance of the electric automobile is continuously improved along with the continuous development of new energy technology, and nowadays, the electric automobile is gradually accepted by the market and favored by consumers due to the advantages of quick starting, zero emission, low noise, low energy consumption and the like.
The crawling function of the electric automobile can realize a plurality of functions such as hill parking, hill starting, following under congested road conditions and the like, in the crawling control of the electric automobile, torque compensation is carried out by calculating a hill resistance distance aiming at the control under an uphill crawling starting working condition, but in the prior art, the calculation of the hill resistance distance is not accurate, and the vehicle still slips; in addition, the prior art does not consider the problem of the forward rush feeling generated in the process of the vehicle crawling and starting on the downhill and the process of starting the vehicle after the vehicle frequently steps on the brake in the congested road condition.
Disclosure of Invention
In view of the above problems, an object of the present invention is to provide a method and a device for controlling crawling of an electric vehicle, which can effectively overcome the defects in the prior art, optimize the crawling performance of the vehicle, and further improve the driving quality.
In order to solve the technical problem, an embodiment of the present invention provides a method for controlling crawling of an electric vehicle, including:
acquiring real-time crawling parameters of a vehicle, wherein the real-time crawling parameters at least comprise a real-time vehicle speed, a target vehicle speed, a gear signal, a longitudinal acceleration, a ramp resistance distance, a ramp hill-holding torque and a crawling output torque;
carrying out PI regulation on the output torque of a vehicle motor according to the difference value between the real-time vehicle speed and the target vehicle speed;
identifying a real-time working condition corresponding to the vehicle based on the output torque regulated by the PI, the real-time vehicle speed, the target vehicle speed, the gear signal, the longitudinal acceleration and the ramp resistance distance;
and performing preset processing on the real-time crawling parameters related to the real-time working conditions according to the real-time working conditions.
As one of the preferable schemes, the real-time working condition at least comprises: the system comprises an uphill starting working condition, an integral torque correction working condition, a downhill starting working condition and an integral torque stopping working condition.
As one preferable scheme, when the vehicle is stationary on a slope, the gear signal is a D gear, the longitudinal acceleration is greater than zero, and the output torque regulated by the PI is smaller than the slope resistance moment, identifying the real-time working condition corresponding to the vehicle as the uphill starting working condition;
when the output torque regulated by the PI is larger than the ramp resistance distance, identifying the real-time working condition corresponding to the vehicle as the integral torque correction working condition;
when the vehicle is still on a slope, the gear signal is a D gear and the longitudinal acceleration is less than zero or when the vehicle is still on the slope, the gear signal is an R gear and the longitudinal acceleration is greater than zero, identifying that the real-time working condition corresponding to the vehicle is the downhill starting working condition;
and when the target vehicle speed is greater than the real-time vehicle speed, identifying the real-time working condition corresponding to the vehicle as the stop integral torque working condition.
As one preferred scheme, the performing, according to the real-time operating condition, the predetermined processing on the real-time crawling parameter related to the real-time operating condition specifically includes:
when the vehicle is identified to be in the uphill starting working condition, the proportional adjustment in the PI adjustment is closed, and the hill resistance distance is corrected through integral adjustment;
when the vehicle is identified to be the integral torque correction working condition, the PI output torque is reduced, and the slope hill-holding torque is corrected;
when the vehicle is identified to be in the downhill starting working condition, the proportional regulation in the PI regulation is closed, and the creep output torque is corrected through integral regulation;
and when the vehicle is identified as the stop integral working condition, closing integral regulation in the PI regulation, and correcting the creep output torque through proportional regulation.
As one of the preferable schemes, the ramp resistance distance is obtained based on a preset ramp resistance distance relational expression;
the ramp resistance distance relational expression is as follows:
Tf＝m*a*r
wherein, TfIs the ramp moment, m is the vehicle reference mass, a is the longitudinal acceleration, and r is the tire rolling radius.
Another embodiment of the present invention provides an electric vehicle creep control apparatus including a controller configured to:
acquiring real-time crawling parameters of a vehicle, wherein the real-time crawling parameters at least comprise a real-time vehicle speed, a target vehicle speed, a gear signal, a longitudinal acceleration, a ramp resistance distance, a ramp hill-holding torque and a crawling output torque;
carrying out PI regulation on the output torque of a vehicle motor according to the difference value between the real-time vehicle speed and the target vehicle speed;
identifying a real-time working condition corresponding to the vehicle based on the output torque regulated by the PI, the real-time vehicle speed, the target vehicle speed, the gear signal, the longitudinal acceleration and the ramp resistance distance;
and performing preset processing on the real-time crawling parameters related to the real-time working conditions according to the real-time working conditions.
As one of the preferable schemes, the real-time working condition at least comprises: the system comprises an uphill starting working condition, an integral torque correction working condition, a downhill starting working condition and an integral torque stopping working condition.
As one of the preferable schemes, the controller is configured to:
when the vehicle is still on a slope, the gear signal is a D gear, the longitudinal acceleration is greater than zero, and the output torque regulated by the PI is smaller than the slope resistance distance, identifying the real-time working condition corresponding to the vehicle as the uphill starting working condition;
when the output torque regulated by the PI is larger than the ramp resistance distance, identifying the real-time working condition corresponding to the vehicle as the integral torque correction working condition;
when the vehicle is still on a slope, the gear signal is a D gear and the longitudinal acceleration is less than zero or when the vehicle is still on the slope, the gear signal is an R gear and the longitudinal acceleration is greater than zero, identifying that the real-time working condition corresponding to the vehicle is the downhill starting working condition;
and when the target vehicle speed is greater than the real-time vehicle speed, identifying the real-time working condition corresponding to the vehicle as the integral stopping torque working condition.
As one of the preferable schemes, the controller is configured to:
when the vehicle is identified to be the hill starting working condition, closing the proportional adjustment in the PI adjustment, and correcting the hill resistance distance through integral adjustment;
when the vehicle is identified to be the integral torque correction working condition, reducing the PI output torque, and correcting the slope hill-holding torque;
when the vehicle is identified to be in the downhill starting working condition, the proportional regulation in the PI regulation is closed, and the creep output torque is corrected through integral regulation;
and when the vehicle is identified as the stop integral working condition, closing integral regulation in the PI regulation, and correcting the creep output torque through proportional regulation.
As one of the preferable schemes, the ramp resistance distance is obtained based on a preset ramp resistance distance relational expression;
the ramp resistance distance relational expression is as follows:
Tf＝m*a*r
wherein, TfIs the ramp moment, m is the vehicle reference mass, a is the longitudinal acceleration, and r is the tire rolling radius.
Compared with the prior art, the embodiment of the invention has the advantages that at least one point is as follows: the real-time crawling parameters of the vehicle are acquired firstly, so that data support is provided for a subsequent control method; the method comprises the steps of firstly determining different crawling working conditions due to different crawling working conditions, then performing preset processing on the different crawling working conditions, wherein the working condition recognition is performed on the slope slipping problem of vehicle starting on a crawling uphill slope, then specific PI adjustment is performed, the crawling uphill slope-holding torque is dynamically coordinated, and the condition that the vehicle does not slip on the crawling uphill slope is guaranteed; aiming at the problem of starting irregularity, working condition identification is carried out, then specific PI adjustment is carried out, creep torque output is reduced, and the irregularity of downhill starting caused by ramp component force is avoided; the method has the advantages that working condition recognition is carried out on the problem of the starting forward rush feeling after the brake is frequently loosened and stepped on, then specific PI adjustment is carried out, the accumulation of integral errors is reduced, PI control is optimized, and the problem of the starting forward rush is solved. Therefore, the crawling control method for the electric automobile can solve the three specific problems of climbing for starting and slipping, uneven downhill starting and forward rushing of the vehicle after frequently loosening and stepping on the brake, so that the starting performance of the crawling function of the vehicle is enhanced, and the driving quality of the vehicle is improved.
Drawings
FIG. 1 is a flow chart illustrating an electric vehicle creep control method according to an embodiment of the present invention;
FIG. 2 is a flow chart illustrating a torque control method for hill start in one embodiment of the present invention;
FIG. 3 is a flowchart illustrating a downhill launch condition torque control method in accordance with one embodiment of the present invention;
FIG. 4 is a flow chart illustrating a method of stopping integral condition torque control in one embodiment of the present invention.
Detailed Description
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.
In the description of the present application, the terms "first", "second", "third", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, features defined as "first," "second," "third," etc. may explicitly or implicitly include one or more of the features. In the description of the present application, "a plurality" means two or more unless otherwise specified.
In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in this application will be understood to be a specific case for those of ordinary skill in the art.
In the description of the present application, it is to be noted that, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention, as those skilled in the art will recognize the specific meaning of the terms used in the present application in a particular context.
An embodiment of the present invention provides a crawling control method for an electric vehicle, and specifically, referring to fig. 1, fig. 1 is a schematic flow chart of the crawling control method for an electric vehicle in one embodiment of the present invention, where the method includes:
s101, acquiring real-time crawling parameters of a vehicle, wherein the real-time crawling parameters at least comprise a real-time vehicle speed, a target vehicle speed, a gear signal, a longitudinal acceleration, a ramp resistance distance, a ramp hill-holding torque and a crawling output torque;
s102, carrying out PI regulation on the output torque of a vehicle motor according to the difference value between the real-time vehicle speed and the target vehicle speed;
s103, identifying a real-time working condition corresponding to the vehicle based on the output torque regulated by the PI, the real-time vehicle speed, the target vehicle speed, the gear signal, the longitudinal acceleration and the ramp resistance distance;
and S104, performing preset processing on the real-time crawling parameters related to the real-time working condition according to the real-time working condition.
It should be noted that the creep control method for the electric vehicle provided by the embodiment of the invention identifies the uphill starting working condition, the integral torque correction working condition, the integral torque stop working condition and the downhill starting working condition according to the motor rotating speed, the vehicle longitudinal acceleration, the driving gear, the creep target vehicle speed and the like, so that the subsequent vehicle can correct the motor output torque through four creep function working conditions, and the creep starting performance of the vehicle is greatly improved. In the control of the uphill crawling starting working condition, in the prior art, a ramp resisting moment is calculated to compensate a crawling torque, a gradient is estimated by a general vehicle longitudinal acceleration sensor or a gradient sensor is directly additionally installed to obtain the gradient, and a partial moment of the vehicle mass along the ramp is calculated to be the ramp resisting moment, on one hand, the acceleration sensor or the gradient sensor is easily interfered by the outside and has low robustness; on the other hand, the passenger quantity on the vehicle directly influences the quality of the whole vehicle, and then influences the accuracy of estimation of the ramp resisting moment, so that the estimation of the ramp resisting moment is inaccurate in the prior art, the output torque of the motor is delayed, and the vehicle can creep and start to slide. In the prior art, the control of the downhill crawling starting working condition of the vehicle and the problem of the forward rush feeling generated by starting the vehicle after the vehicle frequently steps on a brake in a congested road condition are not considered, so that the embodiment of the invention aims to provide the crawling control method for the electric vehicle, which can effectively solve the defects of the prior art, optimize the crawling performance of the vehicle and further improve the driving quality.
Further, in the above embodiment, the real-time operating condition at least includes: the system comprises an uphill starting working condition, an integral torque correction working condition, a downhill starting working condition and a stop integral torque working condition.
Firstly, in this embodiment, since the acceleration sensor is susceptible to external interference and changes in the weight of the entire vehicle, the ramp resisting moment required for hill-holding is dynamically corrected, when the vehicle is uphill and uphill, preferably, the ramp resisting moment required for hill-holding is calculated according to a longitudinal acceleration signal provided by an ESP system of the electric vehicle in a stationary state of the vehicle, then, integral control is performed according to a difference between a target vehicle speed for creep and a real-time vehicle speed, the hill-holding torque output by the motor is dynamically coordinated, and the real-time vehicle speed is controlled to be 0. When the vehicle starts on a hill, the current motor torque is directly output, so that the problem of hysteresis of the output torque of the motor is avoided.
When the vehicle starts on a downhill, the creep torque is actually output by the motor and is unsmooth due to the fact that gravity interferes with the creep torque along the ramp partial torque, and then the real-time speed change is unsmooth.
When the vehicle frequently looses and steps on the brake in the traffic jam operating mode, the integral term in the PI control can constantly accumulate the error, leads to outputting great creep torque when finally loosening the brake, leads to the starting to have the sense of preshoot, through discerning this operating mode, revises creep torque and solves this problem.
Further, in the above embodiment, when the vehicle is stationary on a slope, the gear signal is a D gear, the longitudinal acceleration is greater than zero, and the output torque of the PI regulation is smaller than the slope resistance distance, the real-time working condition corresponding to the vehicle is identified as the hill start working condition;
when the output torque regulated by the PI is larger than the slope resistance distance, identifying the real-time working condition corresponding to the vehicle as the integral torque correction working condition;
when the vehicle is still on a slope, the gear signal is a D gear and the longitudinal acceleration is less than zero or when the vehicle is still on the slope, the gear signal is an R gear and the longitudinal acceleration is greater than zero, identifying that the real-time working condition corresponding to the vehicle is the downhill starting working condition;
and when the target vehicle speed is greater than the real-time vehicle speed, identifying the real-time working condition corresponding to the vehicle as the integral stopping torque working condition.
Further, in the above embodiment, the performing predetermined processing on the real-time crawling parameter related to the real-time operating condition according to the real-time operating condition specifically includes:
when the vehicle is identified to be the hill starting working condition, closing the proportional adjustment in the PI adjustment, and correcting the hill resistance distance through integral adjustment;
when the vehicle is identified to be the integral torque correction working condition, reducing the PI output torque, and correcting the slope hill-holding torque;
when the vehicle is identified to be in the downhill starting working condition, the proportional regulation in the PI regulation is closed, and the creep output torque is corrected through integral regulation;
and when the vehicle is identified as the stop integral working condition, closing integral regulation in the PI regulation, and correcting the creep output torque through proportional regulation.
Specific control logics of various working conditions are explained below, and for convenience of understanding, the uphill starting working condition and the integral torque correction working condition are put into the same control logic for explanation:
specifically, referring to fig. 2, fig. 2 is a schematic flow chart of a method for controlling torque under an uphill starting condition according to an embodiment of the present invention, where the method for controlling torque under an uphill starting condition in the embodiment includes:
s1, when a crawling function is activated, identifying that a vehicle is in a static state according to the rotating speed of a motor; preferably, the vehicle is predicted to be in a static state according to the rotating speed of the motor, namely when the rotating speed of the motor is less than a certain value and is maintained for a certain time, the vehicle can be determined to be static, and the rotating speed condition and the time condition of the actual vehicle are required to be calibrated;
s2, judging that the vehicle is in a static state in the step S1, acquiring a longitudinal acceleration signal a sent by an ESP (electronic stability program) system through a CAN (controller area network) bus, and calculating by utilizing the vehicle reference mass m and the tire rolling radius r to obtain the ramp resisting moment TfI.e. Tf＝m*a*r；
S3, receiving a driving gear signal transmitted by the CAN, and if the gear is D, if the gear is PIController output torque TintgWhen the longitudinal acceleration of the vehicle is larger than zero and the rotating speed of the motor is smaller than a certain value, the vehicle belongs to the starting working condition of ascending a ramp at D gear, the proportional control in the PI controller is closed, and the ramp resisting moment is dynamically corrected for torque only through integral control;
note that the PI controller outputs the torque TintgThe difference between the creep speed and the ramp resisting moment is smaller than a certain value, the certain value needs real vehicle calibration, and the creep output torque cannot continuously fluctuate on the premise of realizing the creep target vehicle speed. The hill start working condition only uses integral control in a PI controller, and the integral control parameter needs real vehicle calibration to realize the crawling target vehicle speed;
s4, after the dynamic correction of the slope resistance torque in the step S3, if the PI controller outputs the torque TintgIf the torque is larger than a certain value of the ramp resisting torque or the vehicle is started normally, the torque control under the uphill starting working condition is quitted; preferably, the PI controller outputs a torque TintgThe difference between the creep speed and the ramp resisting torque is larger than a certain value, the value needs real vehicle calibration, and the creep output torque cannot continuously fluctuate on the premise of realizing the creep target vehicle speed;
s5, after the vehicle is out of the torque control of the uphill starting working condition, when the vehicle does not have a crawling target speed and the vehicle is not started normally, judging the output torque T of the PI controllerintgRelationship to ramp resisting torque if PI controller outputs torque TintgIf the integral torque is larger than a certain value of the ramp resisting torque, the integral torque is overshot, the integral torque is identified as an integral torque correction working condition, the output torque of the PI controller is reduced, and the ramp hill-holding torque is dynamically controlled; preferably, the integral torque correction working condition only uses integral control in a PI controller, the integral control parameter needs real vehicle calibration, and the hill-holding torque is dynamically corrected without the condition of integral torque overshoot;
s6, after the torque control of the uphill starting working condition is quitted, when the speed of the crawling target is greater than 0 or the vehicle is started normally, the speed of the crawling target is adjusted through PI control;
s7, receiving a running gear signal transmitted by the CAN, and if the gear is the R gear, outputting torque T by the PI controllerintgLess than a constant value of ramp moment of resistanceWhen the longitudinal acceleration of the vehicle is smaller than zero and the rotating speed of the motor is larger than a certain value, the vehicle belongs to the R-gear hill starting working condition, the proportional control in the PI controller is closed, and the hill resisting moment dynamic correction is carried out on the torque only through integral control.
Specifically, referring to fig. 3, fig. 3 is a schematic flow chart of a method for controlling torque of a downhill starting condition according to an embodiment of the present invention, where the method for controlling torque of a downhill starting condition includes:
s8, when the crawling function is activated, identifying that the vehicle is in a brake-stepping static state according to the depth of a brake pedal and the rotating speed of a motor;
s9, receiving a driving gear signal transmitted by the CAN, and judging that the vehicle is still on a downhill when the longitudinal acceleration is less than 0 when the gear is a D gear; when the gear is an R gear and the longitudinal acceleration is larger than 0, determining that the vehicle is still on a downhill slope;
s10, releasing a brake pedal, judging that the vehicle has a crawling target speed, and judging that the vehicle is in a downhill slope starting working condition; preferably, the condition that the depth of the brake pedal is less than a certain value can be understood as releasing the brake pedal, and the certain value needs to be calibrated by a real vehicle, so that the condition that the downhill starting working condition is recognized too early or too late to influence the smoothness of the downhill starting is avoided;
s11, identifying the working condition of descending slope and ascending according to the steps from S8 to S10, wherein the PI controller does not perform proportional regulation and only controls the creep output torque through integral regulation; preferably, the torque control of the downhill starting working condition only uses integral control in a PI controller, the integral control parameter needs real-time vehicle calibration, the real-time vehicle speed does not exceed the target vehicle speed, and the smoothness of the downhill starting is ensured;
s12, when the crawling target vehicle speed exceeds the real-time vehicle speed, finishing downhill starting, and quitting the torque control of the downhill starting working condition;
and S13, controlling the target vehicle speed through PI regulation, controlling the working condition of the normal target vehicle speed, and carrying out real vehicle calibration by using proportional control and integral control in the PI control to realize the target vehicle speed control.
Specifically, referring to fig. 4, fig. 4 is a schematic flow chart of a torque control method for stop integration condition in one embodiment of the present invention, where the torque control method for stop integration condition in the embodiment includes:
s14, when the crawling function is activated, judging whether to enter the stop integral working condition torque control according to the difference value between the target vehicle speed and the real-time vehicle speed and the increase rate of the real-time vehicle speed, wherein the real-time vehicle speed is less than the target vehicle speed and greater than 0;
s15, judging that the integral stopping working condition is that the target vehicle speed is larger than a certain real-time vehicle speed and the increase rate of the real-time vehicle speed is larger than a certain value, and the PI controller does not carry out integral adjustment to avoid error accumulation to cause unsmooth vehicle when the vehicle starts with a loose brake, and at the moment, controlling the creep output torque only through proportional adjustment;
it should be noted that the difference between the target vehicle speed and the real-time vehicle speed directly affects the torque output of the PI controller, and needs real-vehicle calibration to avoid a sudden starting feeling; the increasing rate of the real-time vehicle speed represents the acceleration feeling subjectively felt by a driver in the crawling process, the vehicle acceleration feeling in the whole crawling process is inconsistent due to the overlarge increasing rate, real vehicle calibration is needed, and the condition that the stop integral is identified too late is avoided, so that the vehicle acceleration feeling in the whole crawling process is inconsistent; stopping integral working condition torque control, only using proportional control in a PI controller, and calibrating the proportional control parameters by a real vehicle to ensure that the acceleration sense of the vehicle is consistent in the crawling process;
s16, when the real-time vehicle speed approaches the target vehicle speed or the real-time vehicle speed is slowly increased, stopping integral working condition torque control; preferably, the real-time vehicle speed is slowly increased, which means that the expected vehicle acceleration feeling is realized by the current creep torque, and the stop integral working condition is not required to be corrected;
and S17, realizing target vehicle speed control through PI regulation.
Another embodiment of the present invention provides an electric vehicle creep control apparatus including a controller configured to:
acquiring real-time crawling parameters of a vehicle, wherein the real-time crawling parameters at least comprise a real-time vehicle speed, a target vehicle speed, a gear signal, a longitudinal acceleration, a ramp resistance distance, a ramp hill-holding torque and a crawling output torque;
carrying out PI regulation on the output torque of a vehicle motor according to the difference value between the real-time vehicle speed and the target vehicle speed;
identifying a real-time working condition corresponding to the vehicle based on the output torque regulated by the PI, the real-time vehicle speed, the target vehicle speed, the gear signal, the longitudinal acceleration and the ramp resistance distance;
and performing preset processing on the real-time crawling parameters related to the real-time working conditions according to the real-time working conditions.
Further, in the above embodiment, the real-time operating condition at least includes: the system comprises an uphill starting working condition, an integral torque correction working condition, a downhill starting working condition and an integral torque stopping working condition.
Further, in the above embodiment, the controller is configured to:
when the vehicle is still on a slope, the gear signal is a D gear, the longitudinal acceleration is greater than zero, and the output torque regulated by the PI is smaller than the slope resistance distance, identifying the real-time working condition corresponding to the vehicle as the uphill starting working condition;
when the output torque regulated by the PI is larger than the ramp resistance distance, identifying the real-time working condition corresponding to the vehicle as the integral torque correction working condition;
when the vehicle is still on a slope, the gear signal is a D gear and the longitudinal acceleration is less than zero or when the vehicle is still on the slope, the gear signal is an R gear and the longitudinal acceleration is greater than zero, identifying that the real-time working condition corresponding to the vehicle is the downhill starting working condition;
and when the target vehicle speed is greater than the real-time vehicle speed, identifying the real-time working condition corresponding to the vehicle as the integral stopping torque working condition.
Further, in the above embodiment, the controller is configured to:
when the vehicle is identified to be in the uphill starting working condition, the proportional adjustment in the PI adjustment is closed, and the hill resistance distance is corrected through integral adjustment;
when the vehicle is identified to be the integral torque correction working condition, reducing the PI output torque, and correcting the slope hill-holding torque;
when the vehicle is identified to be in the downhill starting working condition, the proportional regulation in the PI regulation is closed, and the creep output torque is corrected through integral regulation;
and when the vehicle is identified to be in the stop integral working condition, closing integral regulation in the PI regulation, and correcting the creep output torque through proportional regulation.
Further, in the above embodiment, the ramp resistance moment is acquired based on a preset ramp resistance moment relational expression;
the ramp resistance distance relational expression is as follows:
Tf＝m*a*r
wherein, TfIs the ramp moment, m is the vehicle reference mass, a is the longitudinal acceleration, and r is the tire rolling radius.
The crawling control method and device for the electric automobile, provided by the embodiment of the invention, have the beneficial effects that at least one point is selected from the following points:
the real-time crawling parameters of the vehicle are acquired firstly, so that data support is provided for a subsequent control method; the method comprises the steps of firstly determining different crawling working conditions due to different crawling working conditions, then performing preset processing on the different crawling working conditions, wherein the working condition recognition is performed on the slope slipping problem of vehicle starting on a crawling uphill slope, then specific PI adjustment is performed, the crawling uphill slope-holding torque is dynamically coordinated, and the condition that the vehicle does not slip on the crawling uphill slope is guaranteed; aiming at the problem of starting irregularity, working condition identification is carried out, then specific PI adjustment is carried out, creep torque output is reduced, and the irregularity of downhill starting caused by ramp component force is avoided; the method has the advantages that working condition recognition is carried out on the problem of the starting forward rush feeling after the brake is frequently loosened and stepped on, then specific PI adjustment is carried out, the accumulation of integral errors is reduced, PI control is optimized, and the problem of the starting forward rush is solved. Therefore, the crawling control method for the electric automobile can solve the three specific problems of climbing for starting and slipping, uneven downhill starting and forward rushing of the vehicle after frequently loosening and stepping on the brake, so that the starting performance of the crawling function of the vehicle is enhanced, and the driving quality of the vehicle is improved.
While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.

Claims (10)

1. The electric vehicle crawling control method is characterized by comprising the following steps of:
acquiring real-time crawling parameters of a vehicle, wherein the real-time crawling parameters at least comprise a real-time vehicle speed, a target vehicle speed, a gear signal, a longitudinal acceleration, a ramp resistance distance, a ramp hill-holding torque and a crawling output torque;
carrying out PI regulation on the output torque of a vehicle motor according to the difference value between the real-time vehicle speed and the target vehicle speed;
identifying a real-time working condition corresponding to the vehicle based on the output torque regulated by the PI, the real-time vehicle speed, the target vehicle speed, the gear signal, the longitudinal acceleration and the ramp resistance distance;
and performing preset processing on the real-time crawling parameters related to the real-time working conditions according to the real-time working conditions.
2. The creep control method of an electric vehicle according to claim 1, wherein the real-time operating conditions at least include: the system comprises an uphill starting working condition, an integral torque correction working condition, a downhill starting working condition and an integral torque stopping working condition.
3. The creep control method of an electric vehicle according to claim 2, wherein when the vehicle is stationary on a slope, the gear signal is a D gear, the longitudinal acceleration is greater than zero, and the output torque of the PI regulation is smaller than the hill resistance distance, the real-time working condition corresponding to the vehicle is identified as the hill start working condition;
when the output torque regulated by the PI is larger than the ramp resistance distance, identifying the real-time working condition corresponding to the vehicle as the integral torque correction working condition;
when the vehicle is still on a slope, the gear signal is a D gear and the longitudinal acceleration is less than zero or when the vehicle is still on the slope, the gear signal is an R gear and the longitudinal acceleration is greater than zero, identifying that the real-time working condition corresponding to the vehicle is the downhill starting working condition;
and when the target vehicle speed is greater than the real-time vehicle speed, identifying the real-time working condition corresponding to the vehicle as the integral stopping torque working condition.
4. The creep control method of an electric vehicle according to claim 3, wherein the pre-processing the real-time creep parameters related to the real-time operating conditions according to the real-time operating conditions is specifically:
when the vehicle is identified to be the hill starting working condition, closing the proportional adjustment in the PI adjustment, and correcting the hill resistance distance through integral adjustment;
when the vehicle is identified to be the integral torque correction working condition, reducing the PI output torque, and correcting the slope hill-holding torque;
when the vehicle is identified to be in the downhill starting working condition, the proportional regulation in the PI regulation is closed, and the creep output torque is corrected through integral regulation;
and when the vehicle is identified to be in the stop integral working condition, closing integral regulation in the PI regulation, and correcting the creep output torque through proportional regulation.
5. The creep control method of an electric vehicle according to claim 1, wherein the slope resistance moment is obtained based on a preset slope resistance moment relation;
the ramp resistance distance relational expression is as follows:
Tf＝m*a*r
wherein, TfIs the ramp moment, m is the vehicle reference mass, a is the longitudinal accelerationAnd r is the tire rolling radius.
6. An electric vehicle creep control apparatus comprising a controller configured to:
acquiring real-time crawling parameters of a vehicle, wherein the real-time crawling parameters at least comprise a real-time vehicle speed, a target vehicle speed, a gear signal, a longitudinal acceleration, a ramp resistance distance, a ramp hill-holding torque and a crawling output torque;
carrying out PI regulation on the output torque of a vehicle motor according to the difference value between the real-time vehicle speed and the target vehicle speed;
identifying a real-time working condition corresponding to the vehicle based on the output torque regulated by the PI, the real-time vehicle speed, the target vehicle speed, the gear signal, the longitudinal acceleration and the ramp resistance distance;
and performing preset processing on the real-time crawling parameters related to the real-time working conditions according to the real-time working conditions.
7. The creep control apparatus for an electric vehicle according to claim 6, wherein the real-time operating conditions at least include: the system comprises an uphill starting working condition, an integral torque correction working condition, a downhill starting working condition and an integral torque stopping working condition.
8. The electric vehicle creep control apparatus of claim 7, wherein the controller is configured to:
when the vehicle is still on a slope, the gear signal is a D gear, the longitudinal acceleration is greater than zero, and the output torque regulated by the PI is smaller than the slope resistance distance, identifying the real-time working condition corresponding to the vehicle as the uphill starting working condition;
when the output torque regulated by the PI is larger than the ramp resistance distance, identifying the real-time working condition corresponding to the vehicle as the integral torque correction working condition;
when the vehicle is still on a slope, the gear signal is a D gear and the longitudinal acceleration is less than zero or when the vehicle is still on the slope, the gear signal is an R gear and the longitudinal acceleration is greater than zero, identifying that the real-time working condition corresponding to the vehicle is the downhill starting working condition;
and when the target vehicle speed is greater than the real-time vehicle speed, identifying the real-time working condition corresponding to the vehicle as the integral stopping torque working condition.
9. The electric vehicle creep control apparatus of claim 8, wherein the controller is configured to:
when the vehicle is identified to be the hill starting working condition, closing the proportional adjustment in the PI adjustment, and correcting the hill resistance distance through integral adjustment;
when the vehicle is identified to be the integral torque correction working condition, reducing the PI output torque, and correcting the slope hill-holding torque;
when the vehicle is identified to be in the downhill starting working condition, the proportional regulation in the PI regulation is closed, and the creep output torque is corrected through integral regulation;
and when the vehicle is identified as the stop integral working condition, closing integral regulation in the PI regulation, and correcting the creep output torque through proportional regulation.
10. The creep control apparatus of an electric vehicle according to claim 6, wherein the slope drag torque is obtained based on a preset slope drag torque relation;
the ramp resistance distance relational expression is as follows:
Tf＝m*a*r
wherein, TfIs the ramp moment, m is the vehicle reference mass, a is the longitudinal acceleration, and r is the tire rolling radius.
CN202110479130.8A 2021-04-29 2021-04-29 Electric automobile crawling control method and device Pending CN115257395A (en)

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Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110479130.8A CN115257395A (en) 2021-04-29 2021-04-29 Electric automobile crawling control method and device

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116450705A (en) * 2023-04-04 2023-07-18 瑞修得信息科技(无锡)有限公司 Method and system for identifying ascending and descending slopes based on vehicle-mounted data acquisition equipment

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116450705A (en) * 2023-04-04 2023-07-18 瑞修得信息科技(无锡)有限公司 Method and system for identifying ascending and descending slopes based on vehicle-mounted data acquisition equipment
CN116450705B (en) * 2023-04-04 2023-12-29 瑞修得信息科技(无锡)有限公司 Method and system for identifying ascending and descending slopes based on vehicle-mounted data acquisition equipment

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