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CN108128210B - Creeping torque output control method and device and automobile - Google Patents

Creeping torque output control method and device and automobile Download PDF

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Publication number
CN108128210B
CN108128210B CN201611092683.3A CN201611092683A CN108128210B CN 108128210 B CN108128210 B CN 108128210B CN 201611092683 A CN201611092683 A CN 201611092683A CN 108128210 B CN108128210 B CN 108128210B
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creep torque
creep
master cylinder
value
vehicle speed
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CN108128210A (en
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严洪江
李文博
邱巍
俞开元
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SAIC Motor Corp Ltd
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SAIC Motor Corp Ltd
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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
    • B60L15/2072—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 drive off
    • 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
    • B60L2250/00—Driver interactions
    • B60L2250/26—Driver interactions by pedal actuation
    • 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

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Electric Propulsion And Braking For Vehicles (AREA)
  • Regulating Braking Force (AREA)

Abstract

A creep torque output control method, a creep torque output control device and an automobile are provided, wherein the method comprises the following steps: detecting the change state of the pressure of a brake master cylinder when starting; outputting a creep torque target value in response to the master cylinder pressure beginning to decrease. According to the scheme of the invention, when the vehicle starts, the interval time from the start of crawling operation of a driver to the output of crawling torque by the motor is shortened, so that the response speed of the crawling torque is accelerated.

Description

Creeping torque output control method and device and automobile
Technical Field
The invention relates to the field of automobile power control, in particular to a creeping torque output control method and device and an automobile.
Background
With the increasing energy crisis and environmental pollution problems worldwide, the requirements on energy conservation and emission reduction of automobiles are increasing. New energy automobiles are receiving more and more attention because of their characteristics of relieving energy pressure and reducing environmental pollution.
The new energy automobile comprises an electric automobile and a hybrid electric automobile, and is driven by a motor in the starting stage of the automobile, and if a driver does not step on an accelerator pedal, the automobile enters a crawling mode. Specifically, the creep mode is used to indicate a function in which the vehicle is slowly moving by itself after the brake pedal is released when the vehicle is in a forward gear or a reverse gear.
In the prior art, when a vehicle driven by a motor runs in a creeping mode, a torque output method comprises the following steps: after the brake pedal is released, the motor outputs preset creeping torque according to the current speed of the vehicle to drive the vehicle to creep. Wherein, aiming at the same vehicle speed, the motor outputs the same creep torque.
However, the creep torque output method described above may result in a creep torque response lag. This is because the motor does not output creep torque until after the driver completely releases the brake pedal. According to the actual test result of the vehicle creep start, the time from the start of releasing the brake pedal by the driver to the complete release of the brake pedal is about 1.5s, namely, the creep torque response lags about 1.5s due to the long time for releasing the brake pedal by manual control.
Further, if the vehicle takes off while creeping on a slope having a certain gradient, the vehicle is liable to roll down the slope. This is because, during the period of time when the creep torque response is delayed, the motor does not output creep torque, the vehicle does not have forward power, and is affected by the gravitational acceleration, and a backward slip phenomenon is likely to occur when starting on a slope, and even when the backward slip distance is too long, a collision accident occurs with a following vehicle.
Disclosure of Invention
The invention aims to provide a creep torque output control method and device and an automobile, which can shorten the interval time from the beginning of creep operation of a driver to the output of creep torque of a motor when the automobile starts, so as to accelerate the response speed of the creep torque.
In order to solve the above technical problem, an embodiment of the present invention provides a creep torque output control method, including the following steps: detecting the change state of the pressure of a brake master cylinder when starting; outputting a creep torque target value in response to the master cylinder pressure beginning to decrease.
Optionally, the outputting the creep torque target value comprises: determining the creep torque target value according to a vehicle state; and controlling the motor to output the creep torque target value.
Optionally, the vehicle state includes a rate of change of the master cylinder pressure, the rate of change of the master cylinder pressure being negative for the same master cylinder pressure and the creep torque target value being larger the absolute value.
Optionally, the determining the creep torque target value according to the vehicle state includes: determining a crawling acceleration level corresponding to the change rate of the pressure of the brake master cylinder according to the change rate of the pressure of the brake master cylinder; searching creep torque output schemes corresponding to the creep acceleration grades according to the creep acceleration grades, wherein different creep acceleration grades correspond to different creep torque output schemes; determining the creep torque target value using the searched creep torque output schedule.
Alternatively, the vehicle state includes a rate of change of a brake pedal opening degree, which is a negative value for the same brake pedal opening degree and the creep torque target value is larger as the absolute value is larger.
Optionally, the determining the creep torque target value according to the vehicle state includes: determining a crawling acceleration level corresponding to the change rate of the opening degree of the brake pedal according to the change rate of the opening degree of the brake pedal; searching creep torque output schemes corresponding to the creep acceleration grades according to the creep acceleration grades, wherein different creep acceleration grades correspond to different creep torque output schemes; determining the creep torque target value using the searched creep torque output schedule.
Optionally, the creep torque output scheme is configured to indicate a correspondence relationship between the creep torque target value and a product term, where the product term is a product of a basic creep torque value and a creep torque suppression coefficient; the basic creep torque value has a corresponding relation with the vehicle speed, and the faster the vehicle speed is, the smaller the basic creep torque value is; the creep torque suppression coefficient has a corresponding relation with the vehicle speed and the brake master cylinder pressure, and the creep torque suppression coefficient is smaller when the vehicle speed is higher and the brake master cylinder pressure is higher.
Optionally, the creep torque output scheme is configured to indicate a correspondence relationship between the creep torque target value and a product term, where the product term is a product of a sum of the base creep torque value and the gradient compensation torque and a creep torque suppression coefficient; the basic creep torque value has a corresponding relation with the vehicle speed, and the faster the vehicle speed is, the smaller the basic creep torque value is; the creep torque suppression coefficient has a corresponding relation with the vehicle speed and the pressure of the brake master cylinder, and the higher the vehicle speed is, the higher the pressure of the brake master cylinder is, and the smaller the creep torque suppression coefficient is; the slope compensation torque has a corresponding relation with a road condition slope value and the vehicle speed, and the greater the road condition slope value is, the slower the vehicle speed is, the greater the slope compensation torque is.
Optionally, the road condition gradient value is calculated according to one or more driving parameters: longitudinal acceleration, vehicle speed and motor rotating speed.
In order to solve the above technical problem, an embodiment of the present invention further provides a creep torque output control device, including: the detection module is suitable for detecting the change state of the pressure of the brake master cylinder when starting; an output module is adapted to output a creep torque target value in response to the master cylinder pressure beginning to decrease.
Optionally, the output module includes: a first determination submodule adapted to determine the creep torque target value in accordance with a vehicle state; and the first output submodule is suitable for controlling the motor to output the creep torque target value.
Optionally, the vehicle state includes a rate of change of the master cylinder pressure, the rate of change of the master cylinder pressure being negative for the same master cylinder pressure and the creep torque target value being larger the absolute value.
Optionally, the first determining sub-module includes: the second determining submodule is suitable for determining a crawling acceleration level corresponding to the change rate of the pressure of the brake master cylinder according to the change rate of the pressure of the brake master cylinder; the first searching sub-module is suitable for searching a crawling torque output scheme corresponding to the crawling acceleration level according to the crawling acceleration level, and different crawling acceleration levels correspond to different crawling torque output schemes; a third determination submodule adapted to determine the creep torque target value using the searched creep torque output schedule.
Alternatively, the vehicle state includes a rate of change of a brake pedal opening degree, which is a negative value for the same brake pedal opening degree and the creep torque target value is larger as the absolute value is larger.
Optionally, the first determining sub-module includes: the fourth determining submodule is suitable for determining a crawling acceleration level corresponding to the brake pedal opening change rate according to the brake pedal opening change rate; the second searching sub-module is suitable for searching a crawling torque output scheme corresponding to the crawling acceleration level according to the crawling acceleration level, and different crawling acceleration levels correspond to different crawling torque output schemes; a fifth determination submodule adapted to determine the creep torque target value using the searched creep torque output schedule.
Optionally, the creep torque output scheme is configured to indicate a correspondence relationship between the creep torque target value and a product term, where the product term is a product of a basic creep torque value and a creep torque suppression coefficient; the basic creep torque value has a corresponding relation with the vehicle speed, and the faster the vehicle speed is, the smaller the basic creep torque value is; the creep torque suppression coefficient has a corresponding relation with the vehicle speed and the brake master cylinder pressure, and the creep torque suppression coefficient is smaller when the vehicle speed is higher and the brake master cylinder pressure is higher.
Optionally, the creep torque output scheme is configured to indicate a correspondence relationship between the creep torque target value and a product term, where the product term is a product of a sum of the base creep torque value and the gradient compensation torque and a creep torque suppression coefficient; the basic creep torque value has a corresponding relation with the vehicle speed, and the faster the vehicle speed is, the smaller the basic creep torque value is; the creep torque suppression coefficient has a corresponding relation with the vehicle speed and the pressure of the brake master cylinder, and the higher the vehicle speed is, the higher the pressure of the brake master cylinder is, and the smaller the creep torque suppression coefficient is; the slope compensation torque has a corresponding relation with a road condition slope value and the vehicle speed, and the greater the road condition slope value is, the slower the vehicle speed is, the greater the slope compensation torque is.
Optionally, the road condition gradient value is calculated according to one or more driving parameters: longitudinal acceleration, vehicle speed and motor rotating speed.
In order to solve the technical problem, an embodiment of the present invention further provides an automobile, which includes the creep torque output control device.
Compared with the prior art, the technical scheme of the embodiment of the invention has the following beneficial effects:
the embodiment of the invention detects the change state of the pressure of the brake master cylinder when the automobile starts; outputting a creep torque target value in response to the master cylinder pressure beginning to decrease. By adopting the scheme of the embodiment of the invention, the interval time from the start of the crawling operation of the driver to the output of the crawling torque by the motor can be shortened when the vehicle starts, so that the response speed of the crawling torque is accelerated, and the adverse effect on the vehicle caused by the response delay of the crawling torque is avoided.
Further, compared with the prior art that the creep torque output by the motor is determined only according to the vehicle speed as a single vehicle state parameter, the embodiment of the invention can judge the creep acceleration intention of a driver according to various vehicle states of the automobile and select a corresponding creep torque output scheme, thereby meeting different requirements of different drivers on creep torque output when different operations are carried out.
Further, compared with the prior art that the same creep torque is provided for both a slope and a flat ground, the creep torque can be adjusted according to the road condition and the gradient of the vehicle, so that the problem that the motor is locked up and generates heat due to insufficient creep torque when the vehicle starts on the slope is solved, and the motor is effectively protected.
Furthermore, the embodiment of the invention does not need to add an additional sensor, can be finished by only using a program to instruct related hardware, is favorable for saving cost and keeps the space utilization rate in the vehicle.
Drawings
FIG. 1 is a flow chart of a creep torque output control method in an embodiment of the present invention.
FIG. 2 is a flow chart of a method of determining a creep torque target value in an embodiment of the present invention.
FIG. 3 is a flow chart of another method of determining a creep torque target value in an embodiment of the present invention.
Fig. 4 is a schematic structural diagram of a creep torque output control device in an embodiment of the present invention.
Fig. 5 is a schematic structural diagram of an output module in an embodiment of the present invention.
Fig. 6 is a schematic structural diagram of a first determination submodule in the embodiment of the present invention.
Fig. 7 is a schematic structural diagram of another first determination submodule in the embodiment of the present invention.
Detailed Description
As mentioned above, in the vehicle starting stage, the new energy vehicle is mostly driven by the motor, and when the vehicle driven by the motor runs in the crawling mode, the torque output method is as follows: after the brake pedal is released, the motor outputs preset creeping torque according to the current speed of the vehicle to drive the vehicle to creep. Wherein, aiming at the same vehicle speed, the motor outputs the same creep torque. However, the creep torque output method described above causes a creep torque response lag, and if the vehicle starts to creep on a slope having a certain gradient, the vehicle is likely to slip down the slope.
The inventor of the present invention has found through research that the key of the above problem is that the motor does not output creep torque during the period from the time when the driver releases the brake pedal to the time when the brake pedal is completely released in the prior art, so that the vehicle has no forward power.
The embodiment of the invention detects the change state of the pressure of the brake master cylinder when the automobile starts; outputting a creep torque target value in response to the master cylinder pressure beginning to decrease. By adopting the scheme of the embodiment of the invention, when the vehicle is in a creeping mode, the interval time from the starting of creeping operation of a driver to the output of creeping torque of the motor can be shortened, so that the response speed of the creeping torque is accelerated, and the adverse effect on the vehicle caused by the response delay of the creeping torque is avoided.
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.
Referring to fig. 1, fig. 1 is a flowchart of a creep torque output control method in an embodiment of the present invention. The brake pedal opening creep torque output control method may include steps S101 to S102. The creep torque output control method is used for a new energy automobile.
Step S101: detecting the change state of the pressure of a brake master cylinder when starting;
step S102: outputting a creep torque target value in response to the master cylinder pressure beginning to decrease.
In the specific implementation of step S101, the determination as to whether the vehicle is in a starting state, i.e., about to enter into a creep state, may be based on the following elements: the opening degree of an accelerator pedal is lower than a preset opening degree threshold value, the vehicle is not in a parking state, and a vehicle gear is in a forward gear or a reverse gear. If the above conditions are all satisfied, it may be determined that the vehicle is in a launch state, i.e., about to creep. Of course, the determination condition of whether to start or not is not limited to this, and may be any other appropriate manner.
The accelerator pedal opening can be used for defining the stepping depth of the accelerator pedal, for example, the accelerator opening can be expressed by using signals of 0-100%, 0 represents that the accelerator is not stepped on, and 100% represents that the accelerator is stepped on to the maximum opening. According to the definition of the crawling mode in the background technology, when the accelerator pedal is pressed down, the driver can be indicated to intentionally operate the automobile to enter the driving mode, and then the driver is judged not to have the crawling intention. As a non-limiting example, the preset opening degree threshold may be set to 3%.
The parking state may be used to define a parking brake state of the vehicle, and when the parking state is not released, it may indicate that the vehicle is not in a starting state and the driver does not have a crawling intention.
The vehicle gear information may include a forward gear, a reverse gear, a neutral gear, a parking gear, etc., and when the vehicle is in the neutral gear and the parking gear, it may indicate that the vehicle is not in a starting state and the driver has no intention of crawling.
The master cylinder pressure is the pressure of a master cylinder in the brake system. The master cylinder pressure can indirectly represent the force applied to the brake pedal by the driver or the depth of depression of the brake pedal. Specifically, when the driver depresses the brake pedal, the master cylinder piston of the brake hydraulic system is pushed forward, and since the liquid in the master cylinder and the entire brake hydraulic system is incompressible, the force acting on the master cylinder piston is transmitted by the liquid to the inner surface of the entire system, which is called the master cylinder pressure.
Specifically, the changing state of the master cylinder pressure can be used to indicate the operation condition of the brake pedal by the driver. The deeper the brake pedal is stepped on, the greater the brake master cylinder pressure is; the brake pedal is released and the master cylinder pressure is reduced accordingly.
Further, the accelerator pedal opening degree CAN be acquired in a vehicle body CAN signal form through a vehicle Controller Area Network (CAN) after being detected by a pedal opening degree sensor; the parking state of the vehicle, the vehicle gear information and the master cylinder pressure CAN be directly obtained through the CAN.
In a specific implementation of step S102, a creep torque target value is output in response to the master cylinder pressure beginning to decrease.
In specific implementation, the creep torque target value is output when the pressure of the brake master cylinder begins to decrease, and the creep torque response speed can be increased. This is because the start of the reduction in the master cylinder pressure means that the driver starts releasing the brake pedal, and the creep torque target value is output at this time, which can shorten the interval from the start of creep operation by the driver to the output of creep torque by the motor.
Compared with the prior art, the embodiment of the invention effectively solves the problem of creep torque response lag by outputting the creep torque after the driver completely releases the brake pedal. When the vehicle starts creeping on a slope with a certain gradient, the creeping pressure is output immediately when the driver starts to release the brake pedal, which helps to avoid the vehicle from rolling backwards.
Further, when the creep torque is output, the filter may be set using a conventional filter setting method to smooth the torque output.
In this embodiment, the creep torque target value may be determined according to the vehicle state, and the motor may be controlled to output the creep torque target value.
Compared with the prior art that the preset creep torque is output to drive the vehicle to run only after the brake pedal is released, the embodiment of the invention can determine and output the creep torque according to the vehicle state, thereby realizing continuous control and real-time adjustment of the creep torque and being beneficial to meeting different driving requirements during creep starting under different working conditions.
In one particular embodiment, the vehicle condition may include a rate of change of the master cylinder pressure, the rate of change of the master cylinder pressure being negative for the same master cylinder pressure and the creep torque target value being greater the absolute value.
This is because, when the master cylinder pressure increases, the rate of change of the master cylinder pressure becomes positive, indicating that the driver is depressing the brake pedal, and it can be recognized that the driver has no intention to accelerate by creeping. The creep torque target value needs to be determined and output only if the rate of change of the master cylinder pressure is negative when the master cylinder pressure is reduced, indicating that the driver is releasing the brake pedal.
Further, when the change rate of the pressure of the brake master cylinder is a negative value, if the pressure of the brake master cylinder is slowly reduced, the driver is indicated to slowly lift the brake pedal, the creep acceleration intention of the driver is identified to be weak, and a small creep torque target value can be output; if the master cylinder pressure is rapidly reduced, which indicates that the driver is rapidly lifting the brake pedal, it can be recognized that the creep acceleration intention of the driver is strong, and a large creep torque target value can be output.
Further, when calculating the rate of change of the master cylinder pressure, the calculated rate of change may be filtered using a conventional filtering setting method to obtain a gentle value.
One method of determining a creep torque target based on the rate of change of the master cylinder pressure may be found in FIG. 2. The method may include steps S201 to S203.
Step S201: and determining a creep acceleration level corresponding to the change rate of the pressure of the brake master cylinder according to the change rate of the pressure of the brake master cylinder.
Step S202: and searching a creep torque output scheme corresponding to the creep acceleration grade according to the creep acceleration grade, wherein different creep acceleration grades correspond to different creep torque output schemes.
Step S203: determining the creep torque target value using the searched creep torque output schedule.
In the specific implementation of step S201, the creep acceleration level is used to indicate the creep torque that needs to be output by the motor when the vehicle creeps, and the higher the creep acceleration level, the greater the creep torque output by the motor is.
As a non-limiting example, creep acceleration ratings can be divided into three categories: inhibited, mild and aggressive.
When the creep acceleration level is the first level, for example, the suppression level, corresponding to the rate of change of the master cylinder pressure >0, it can be recognized that the driver has no intention of creep acceleration, and accordingly, no creep torque is output.
When the creep acceleration level is a second level, for example, a mild level, the creep acceleration intention of the driver may be recognized to be weak in accordance with the change rate of the master cylinder pressure <0 and the absolute value is small, and accordingly, a small creep torque target value is output, which is suitable for a driver who desires to slowly accelerate the vehicle in a creep state.
When the creep acceleration level is the third level, for example, the acceleration level, the creep acceleration intention of the driver is recognized to be strong corresponding to the change rate of the master cylinder pressure being <0 and the absolute value being large, and accordingly, a large creep torque target value is output, which is suitable for a driver who expects the vehicle to accelerate rapidly in a creep state.
As a non-limiting example, it may be set to go from a mild level of creep acceleration to a aggressive level of creep acceleration when the rate of change of the master cylinder pressure is less than-20 Bar/s.
In the specific implementation of step S202, a creep torque output scheme corresponding to the creep acceleration level is searched according to the creep acceleration level, and different creep acceleration levels correspond to different creep torque output schemes.
In a specific implementation, the creep torque output schedule has a correspondence with the creep acceleration level. And the creep torque output scheme is preset for each creep acceleration level, such as a suppression level, a smooth level and a propulsion level. By selecting the creep acceleration grade, the motor can be controlled to output the creep torque target value in the corresponding creep torque output scheme.
In an implementation of step S203, the creep torque target value is determined using the searched creep torque output schedule.
In one particular application of an embodiment of the present invention, the creep torque output scheme is used to indicate a correspondence of the creep torque target value to a product term that is a product of a base creep torque value and a creep torque suppression coefficient.
Specifically, for each particular creep acceleration level, a creep torque output scheme is used to indicate that a base creep torque value, a creep torque suppression coefficient, and the creep torque target value have a correspondence. The creep torque target value may be calculated by the formula:
the creep torque target value is a basic creep torque value and a creep torque suppression coefficient;
the basic creep torque value has a corresponding relation with the vehicle speed, and the faster the vehicle speed is, the smaller the basic creep torque value is.
The creep torque suppression coefficient has a corresponding relation with the vehicle speed and the brake master cylinder pressure, and the creep torque suppression coefficient is smaller when the vehicle speed is higher and the brake master cylinder pressure is higher.
In specific implementation, a detailed corresponding relation between the vehicle speed and the basic creep torque value and a corresponding relation between the vehicle speed, the pressure of the brake master cylinder and the creep torque suppression coefficient can be obtained through a real vehicle calibration test method according to calibration software.
It can be understood that, since parameters (such as vehicle speed, brake master cylinder pressure) which can be set in the test and correspondingly obtained product terms (such as basic creep torque value and creep torque suppression coefficient) are limited, interpolation can be adopted for the untested data part, so as to obtain the complete corresponding relation. Specifically, the interpolation method is also called "interpolation method", and may be a calculation method in which a specific function is created using function values of a number of points known in a certain interval of the function f (x), and values of the specific function are used as approximate values of the function f (x) at other points in the interval, thereby obtaining an unknown value.
In another preferred application of the embodiment of the present invention, the creep torque output scheme is for indicating a correspondence of the creep torque target value with a product term which is a product of a sum of a base creep torque value and a gradient compensation torque and a creep torque suppression coefficient.
Specifically, for each particular creep acceleration level, a creep torque output scheme is used to indicate that a base creep torque value, a creep torque suppression coefficient, a grade compensation torque have a correspondence with the creep torque target value. The creep torque target value may be calculated by the formula:
a creep torque target value (a base creep torque value + a grade compensation torque) and a creep torque suppression coefficient;
the basic creep torque value has a corresponding relation with the vehicle speed, and the faster the vehicle speed is, the smaller the basic creep torque value is.
The creep torque suppression coefficient has a corresponding relation with the vehicle speed and the brake master cylinder pressure, and the creep torque suppression coefficient is smaller when the vehicle speed is higher and the brake master cylinder pressure is higher.
The slope compensation torque has a corresponding relation with a road condition slope value and the vehicle speed, and the greater the road condition slope value is, the slower the vehicle speed is, the greater the slope compensation torque is.
In specific implementation, the detailed corresponding relation between the road condition gradient value, the vehicle speed and the basic creep torque value can be obtained through a real vehicle calibration test method according to calibration software.
The road condition gradient value is calculated according to one or more driving parameters: longitudinal acceleration, vehicle speed and motor rotating speed.
When the vehicle is stationary, the road condition gradient value may be obtained by the following calculation formula.
Figure BDA0001168773940000111
Wherein beta represents a road condition gradient value;
aLongtAccrepresenting the longitudinal acceleration of the vehicle, which is used for indicating the acceleration formed by the component force of the gravity of the vehicle in the driving direction of the vehicle on the slope;
g is the acceleration of gravity.
When the vehicle is in a driving state, the road condition gradient value is related to the longitudinal acceleration, the vehicle speed and the motor rotating speed and can be obtained by an existing conventional calculation method.
Further, the ramp angle and the longitudinal acceleration of the vehicle CAN be directly obtained through the CAN.
Compared with the prior art, the same creep torque is provided for the slope and the flat ground, so that the motor is easy to block, rotate and heat.
Further, compared with the prior art that the preset creep torque is determined only by taking the vehicle speed as a single vehicle state parameter, the embodiment of the invention can determine and output the creep torque according to various vehicle state parameters, thereby realizing continuous control and real-time regulation of the creep torque and being beneficial to meeting the increasingly complex driving conditions and the operation requirements of drivers.
In another embodiment, the vehicle condition according to which the creep torque target value is determined may include a rate of change of a brake pedal opening degree, which is negative for the same brake pedal opening degree and is larger the absolute value.
This is because, when the brake pedal opening degree increases, the rate of change of the brake pedal opening degree becomes a positive value, which indicates that the driver is depressing the brake pedal, and it can be recognized that the driver has no intention to accelerate by creeping. The creep torque target value needs to be determined and output only if the rate of change of the brake pedal opening is negative when the brake pedal opening decreases, indicating that the driver is releasing the brake pedal.
Further, when the change rate of the opening degree of the brake pedal is a negative value, if the opening degree of the brake pedal is slowly reduced, the driver can be identified as slowly lifting the brake pedal, and the creep acceleration intention of the driver is weak, and a small creep torque target value can be output; if the brake pedal opening is rapidly reduced, indicating that the driver is rapidly raising the brake pedal, it can be recognized that the creep acceleration intention of the driver is strong, and at this time, a large creep torque target value can be output.
A method of determining a creep torque target value based on a rate of change of the brake pedal opening in the another embodiment may be found in fig. 3. The method may include steps S301 to S303.
Step S301: and determining a creep acceleration level corresponding to the change rate of the opening degree of the brake pedal according to the change rate of the opening degree of the brake pedal.
Step S302: and searching a creep torque output scheme corresponding to the creep acceleration grade according to the creep acceleration grade, wherein different creep acceleration grades correspond to different creep torque output schemes.
Step S303: determining the creep torque target value using the searched creep torque output schedule.
In the specific implementation of step S301, the creep acceleration level is used to indicate a creep torque that needs to be output by the motor when the vehicle creeps, and a higher creep acceleration level indicates a higher creep torque output by the motor.
As a non-limiting example, creep acceleration ratings can be divided into three categories: inhibited, mild and aggressive.
When the creep acceleration level is a first level, for example, a suppression level, corresponding to the rate of change of the brake pedal opening degree >0, it can be recognized that the driver has no intention of creep acceleration, and accordingly, no creep torque is output.
When the creep acceleration level is a second level, for example, a mild level, the creep acceleration intention of the driver is recognized to be weak in accordance with the change rate of the brake pedal opening degree <0 and the absolute value is small, and accordingly, a small creep torque target value is output, which is suitable for a driver who desires to slowly accelerate the vehicle in a creep state.
When the creep acceleration level is at the third level, for example, the aggressive level, the creep acceleration intention of the driver is recognized to be strong corresponding to the change rate of the brake pedal opening degree <0 and the absolute value is large, and accordingly, a large creep torque target value is output, which is suitable for a driver who expects the vehicle to accelerate rapidly in a creep state.
As a non-limiting example, it is possible to set a creep acceleration level from a mild level to a aggressive level when the rate of change of the brake pedal opening is less than-30%/s.
Further, the brake pedal opening may be acquired in the form of a vehicle body CAN signal after being detected by a pedal opening sensor.
In a specific implementation, the execution of step S302 and step S303 is performed with reference to the description of step S202 and step S203 in fig. 2, and details are not repeated here.
In the embodiment of the invention, the creep torque can be determined and output at intervals of preset time according to the preset time interval, so that the continuous control and real-time adjustment of the creep torque are realized, and the requirement of a driver on the output of the creep torque is favorably met. As a non-limiting example, the preset time interval may be set to 200 ms.
Referring to fig. 4, fig. 4 is a schematic structural diagram of a creep torque output control device in an embodiment of the present invention.
The creep torque output control means may include a detection module 41 and an output module 42.
The detection module 41 is adapted to detect a change state of the master cylinder pressure at the time of starting. The output module 42 is adapted to output a creep torque target value in response to the master cylinder pressure beginning to decrease.
Further, a schematic structural diagram of an output module 42 in the embodiment of the present invention may refer to fig. 5. As shown in fig. 5, the output module 42 may include a first determination submodule 51 and a first output submodule 52.
Wherein the first determination submodule 51 is adapted to determine the creep torque target value in dependence on a vehicle condition. The first output submodule 52 is adapted to control the motor to output the creep torque target value.
Further, a schematic structural diagram of a first determining submodule 51 in the embodiment of the present invention may refer to fig. 6. As shown in fig. 6, the first determination sub-module 51 may include a second determination sub-module 511, a first lookup sub-module 512, and a third determination sub-module 513.
Wherein the second determining submodule 511 is adapted to determine a creep acceleration level corresponding to the rate of change of the master cylinder pressure, based on the rate of change of the master cylinder pressure. The first searching sub-module 512 is adapted to search for a crawling torque output scheme corresponding to the crawling acceleration level according to the crawling acceleration level, wherein different crawling acceleration levels correspond to different crawling torque output schemes. The third determination submodule 513 is adapted to determine the creep torque target value using the creep torque output scheme found.
The embodiment of the present invention further discloses another first determining submodule 51, and a schematic structural diagram thereof may refer to fig. 7. As shown in fig. 7, the first determination sub-module 51 may include a fourth determination sub-module 514, a second lookup sub-module 515, and a fifth determination sub-module 516.
Wherein the fourth determination submodule 514 is adapted to determine a creep acceleration level corresponding to the brake pedal opening change rate according to the brake pedal opening change rate. The second lookup sub-module 515 is adapted to lookup a creep torque output scheme corresponding to the creep acceleration level according to the creep acceleration level, different creep acceleration levels corresponding to different creep torque output schemes. The fifth determination sub-module 516 is adapted to determine the creep torque target value using the creep torque output schedule found.
For more details of the creep torque output control device, reference is made to the above description of the creep torque output control method, which is not repeated herein.
The embodiment of the invention also provides an automobile which comprises the creep torque output control device and can execute the creep torque output control method based on the opening degree of the brake pedal.
Those skilled in the art will appreciate that all or part of the steps in the methods of the above embodiments may be implemented by hardware related to instructions of a program, which may be stored in a computer-readable storage medium, and the storage medium may include: ROM, RAM, magnetic or optical disks, and the like.
Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (7)

1. A creep torque output control method, comprising the steps of:
detecting the change state of the pressure of a brake master cylinder when starting;
outputting a creep torque target value in response to the master cylinder pressure beginning to decrease;
the output creep torque target value includes:
determining the creep torque target value according to a vehicle state; controlling a motor to output the creep torque target value; wherein the vehicle state includes a rate of change of the master cylinder pressure, the rate of change of the master cylinder pressure being negative for the same master cylinder pressure and the creep torque target value being larger the absolute value is;
the determining the creep torque target value based on the vehicle state includes:
determining a crawling acceleration level corresponding to the change rate of the pressure of the brake master cylinder according to the change rate of the pressure of the brake master cylinder; searching creep torque output schemes corresponding to the creep acceleration grades according to the creep acceleration grades, wherein different creep acceleration grades correspond to different creep torque output schemes; determining the creep torque target value by using the searched creep torque output scheme;
the creep torque output scheme is used for indicating the corresponding relation between the creep torque target value and a product term, wherein the product term is the product of a basic creep torque value and a creep torque suppression coefficient; the basic creep torque value has a corresponding relation with the vehicle speed, and the faster the vehicle speed is, the smaller the basic creep torque value is; the creep torque suppression coefficient has a corresponding relation with the vehicle speed and the brake master cylinder pressure, and the creep torque suppression coefficient is smaller when the vehicle speed is higher and the brake master cylinder pressure is higher.
2. The creep torque output control method according to claim 1, wherein the creep torque output scheme is for indicating a correspondence of the creep torque target value with a product term that is a product of a sum of a base creep torque value and a gradient compensation torque and a creep torque suppression coefficient;
the basic creep torque value has a corresponding relation with the vehicle speed, and the faster the vehicle speed is, the smaller the basic creep torque value is;
the creep torque suppression coefficient has a corresponding relation with the vehicle speed and the pressure of the brake master cylinder, and the higher the vehicle speed is, the higher the pressure of the brake master cylinder is, and the smaller the creep torque suppression coefficient is;
the slope compensation torque has a corresponding relation with a road condition slope value and the vehicle speed, and the greater the road condition slope value is, the slower the vehicle speed is, the greater the slope compensation torque is.
3. The creep torque output control method according to claim 2, wherein the road condition gradient value is calculated according to one or more of the following driving parameters: longitudinal acceleration, vehicle speed and motor rotating speed.
4. A creep torque output control apparatus, comprising:
the detection module is suitable for detecting the change state of the pressure of the brake master cylinder when starting;
an output module adapted to output a creep torque target value in response to the master cylinder pressure beginning to decrease;
the output module includes:
a first determination submodule adapted to determine the creep torque target value in accordance with a vehicle state; wherein the vehicle state includes a rate of change of the master cylinder pressure, the rate of change of the master cylinder pressure being negative for the same master cylinder pressure and the creep torque target value being larger the absolute value is;
the first output submodule is suitable for controlling the motor to output the creep torque target value;
the first determination submodule includes:
the second determining submodule is suitable for determining a crawling acceleration level corresponding to the change rate of the pressure of the brake master cylinder according to the change rate of the pressure of the brake master cylinder;
the first searching sub-module is suitable for searching a crawling torque output scheme corresponding to the crawling acceleration level according to the crawling acceleration level, and different crawling acceleration levels correspond to different crawling torque output schemes;
a third determination submodule adapted to determine the creep torque target value using the searched creep torque output scheme; wherein the creep torque output scheme is used for indicating the corresponding relation between the creep torque target value and a product term, and the product term is the product of a basic creep torque value and a creep torque suppression coefficient; the basic creep torque value has a corresponding relation with the vehicle speed, and the faster the vehicle speed is, the smaller the basic creep torque value is; the creep torque suppression coefficient has a corresponding relation with the vehicle speed and the brake master cylinder pressure, and the creep torque suppression coefficient is smaller when the vehicle speed is higher and the brake master cylinder pressure is higher.
5. The creep torque output control apparatus according to claim 4, wherein the creep torque output scheme is for indicating a correspondence of the creep torque target value with a product term that is a product of a sum of a base creep torque value and a gradient compensation torque and a creep torque suppression coefficient;
the basic creep torque value has a corresponding relation with the vehicle speed, and the faster the vehicle speed is, the smaller the basic creep torque value is;
the creep torque suppression coefficient has a corresponding relation with the vehicle speed and the pressure of the brake master cylinder, and the higher the vehicle speed is, the higher the pressure of the brake master cylinder is, and the smaller the creep torque suppression coefficient is;
the slope compensation torque has a corresponding relation with a road condition slope value and the vehicle speed, and the greater the road condition slope value is, the slower the vehicle speed is, the greater the slope compensation torque is.
6. The creep torque output control device according to claim 5, wherein the road condition gradient value is calculated according to one or more of the following driving parameters: longitudinal acceleration, vehicle speed and motor rotating speed.
7. An automobile characterized by comprising the creep torque output control apparatus according to any one of claims 4 to 6.
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Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108909528B (en) * 2018-07-12 2021-04-23 哈尔滨东安汽车发动机制造有限公司 P2 architecture hybrid idle speed control method
CN112477862B (en) * 2019-08-23 2022-03-25 上海汽车集团股份有限公司 Method and device for realizing vehicle uphill starting auxiliary control
CN110667401A (en) * 2019-09-29 2020-01-10 上海伊控动力系统有限公司 Pure electric vehicle electric crawling starting torque control method
CN111645532A (en) * 2019-12-03 2020-09-11 摩登汽车有限公司 Motor torque control method and system
CN111688502A (en) * 2020-06-16 2020-09-22 宜宾凯翼汽车有限公司 Creep control method for electric vehicle
CN112109711B (en) * 2020-09-14 2021-07-13 恒大新能源汽车投资控股集团有限公司 Vehicle creep control method, device, electronic device and storage medium
CN114352719B (en) * 2020-09-27 2023-08-11 长城汽车股份有限公司 Creeping speed control method and device, storage medium, electronic equipment and vehicle
CN112406866B (en) * 2020-11-18 2022-08-30 东风汽车有限公司 Starting control method in automatic parking mode, storage medium and vehicle-mounted electronic device
CN112549992B (en) * 2020-12-18 2022-04-01 智新控制系统有限公司 Creep control method and system for ramp-free sensor of pure electric vehicle
CN114670673B (en) * 2022-03-11 2024-02-27 凯博易控车辆科技(苏州)股份有限公司 Braking torque control system and method
CN114932907A (en) * 2022-06-30 2022-08-23 奇瑞汽车股份有限公司 Vehicle starting method and device
CN115648961B (en) * 2022-09-15 2023-09-12 广州汽车集团股份有限公司 Vehicle control method and device and related equipment

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3612711B2 (en) * 2002-07-03 2005-01-19 トヨタ自動車株式会社 Automobile
JP3922205B2 (en) * 2003-04-14 2007-05-30 日産自動車株式会社 Vehicle motor torque control device
JP3931852B2 (en) * 2003-07-22 2007-06-20 トヨタ自動車株式会社 Electric vehicle and control method thereof
US7894968B2 (en) * 2007-03-13 2011-02-22 Gm Global Technology Operations, Inc. Accelerator/brake pedal management for torque-based engine control
JP5230703B2 (en) * 2010-09-03 2013-07-10 ジヤトコ株式会社 Engine automatic stop vehicle and control method thereof
KR20130053036A (en) * 2011-11-14 2013-05-23 현대자동차주식회사 System and method for controlling creep torque of vehicle
CN103029596B (en) * 2012-10-30 2015-07-08 荣成华泰汽车有限公司 Creep control method and device for electric automobile and electric automobile
KR101601430B1 (en) * 2014-06-13 2016-03-09 현대자동차주식회사 Method for controlling creep torque of motor driven vehicle

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