CN114633636A - Electric vehicle control method and device, storage medium and vehicle control unit - Google Patents
Electric vehicle control method and device, storage medium and vehicle control unit Download PDFInfo
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- CN114633636A CN114633636A CN202210301748.XA CN202210301748A CN114633636A CN 114633636 A CN114633636 A CN 114633636A CN 202210301748 A CN202210301748 A CN 202210301748A CN 114633636 A CN114633636 A CN 114633636A
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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
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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
- 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
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- 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
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- Y02T10/72—Electric energy management in electromobility
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Abstract
The invention provides an electric vehicle control method, an electric vehicle control device, a storage medium and a vehicle control unit, wherein the method comprises the following steps: judging whether to enter a crawling mode according to the current speed of the electric vehicle; if the electric vehicle is judged to enter the crawling mode, acquiring the current opening degree of a brake pedal of the electric vehicle; determining a first creep torque of the electric vehicle according to the vehicle speed and the brake pedal opening degree; sending the first creep torque to a motor controller of the electric vehicle. The scheme provided by the invention can enable the motor output shaft gear and the transmission shaft gear to keep a meshed state all the time, thereby weakening or eliminating the phenomena of gear beating and shaking.
Description
Technical Field
The invention relates to the field of control, in particular to a method and a device for controlling an electric vehicle, a storage medium and a vehicle control unit.
Background
For a new energy electric Vehicle system, the new energy electric Vehicle system is a complex system composed of a plurality of subsystems, and mainly comprises a battery, a motor, an electric Control system and the like, wherein the subsystems are communicated with each other and coordinated with each other, and are controlled and managed by a Vehicle Control Unit (VCU). The vehicle control unit is a core control component of the whole vehicle, is equivalent to the brain of the vehicle, can collect signals of all components, such as an accelerator pedal signal, a brake pedal signal and the like, and controls the controllers of related components to execute corresponding actions after making corresponding judgment so as to drive the electric vehicle to normally run. As electric automobile's wisdom management center, vehicle control unit main function includes: the method comprises the following steps of power on and power off management, driving torque control, energy recovery management, whole vehicle fault diagnosis and processing, vehicle state monitoring and the like. The system and a Motor Control Unit (MCU) jointly form a power system of the whole vehicle.
When the VCU sends a torque command to the MCU to control the motor to drive or brake, the motor drives the vehicle to run or stop through the transmission system. The motor and the transmission system are in torque transmission through gears, and backlash impact is a common phenomenon in the transmission system. Due to the existence of gear gaps, in the control process of a transmission system, a driver is difficult to accurately control the torque under the switching of operating conditions such as accelerator operation, brake operation and the like. When the VCU does not send a torque signal to the MCU or the torque is small (such as low-speed starting and low-speed light brake stepping), the output end of the motor and the transmission gear are in a non-meshed state, and simultaneously, because a gap exists between the gears, the gears can freely shake without control, and the gear beating condition can occur between the gears, so that the vehicle shakes. If the gear beating phenomenon exists for a long time, gears rub with each other, so that gaps between the gears are gradually enlarged, gear beating is aggravated finally, and vehicle shaking is more obvious. Therefore, the running smoothness and the driving experience of the whole vehicle are influenced.
Disclosure of Invention
The present invention is directed to overcome the drawbacks of the related art, and provides a method and an apparatus for controlling an electric vehicle, a storage medium, and a vehicle control unit, so as to solve the problem of vehicle shake caused by backlash impact during driving of the electric vehicle in the related art.
One aspect of the present invention provides an electric vehicle control method, including: judging whether to enter a crawling mode according to the current speed of the electric vehicle; if the electric vehicle is judged to enter the crawling mode, acquiring the current opening degree of a brake pedal of the electric vehicle; determining a first creep torque of the electric vehicle according to the vehicle speed and the brake pedal opening degree; sending the first creep torque to a motor controller of the electric vehicle.
Optionally, determining a first creep torque of the electric vehicle according to the vehicle speed and the brake pedal opening degree comprises: determining a second creep torque of the electric vehicle according to the vehicle speed; determining a first creep torque of the electric vehicle according to the second creep torque and the brake pedal opening degree.
Optionally, determining a first creep torque of the electric vehicle according to the second creep torque and/or the brake pedal opening degree comprises: determining that the first creep torque is equal to the second creep torque when the brake pedal opening is 0; when the opening degree of the brake pedal is larger than or equal to a preset opening degree, determining that the first creep torque is 0; and when the opening degree of the brake pedal is smaller than a preset opening degree, calculating a first creep torque of the electric vehicle according to the second creep torque, the opening degree of the brake pedal and the preset opening degree.
Optionally, calculating a first creep torque of the electric vehicle according to the second creep torque, the brake pedal opening degree and the preset opening degree comprises: determining a first creep torque of the electric vehicle according to the second creep torque, the opening degree of the brake pedal and the preset opening degree by using the following formula:
wherein T is the second creep torque, T' is the first creep torque, percent is the opening degree of the brake pedal, and P is the preset opening degree.
Another aspect of the present invention provides an electric vehicle control apparatus, including: the judging unit is used for judging whether to enter a crawling mode according to the current speed of the electric vehicle; the obtaining unit is used for obtaining the current opening degree of a brake pedal of the electric vehicle if the judging unit judges that the electric vehicle enters the crawling mode; a determination unit for determining a first creep torque of the electric vehicle according to the vehicle speed and the brake pedal opening; a control unit to send the first creep torque to a motor controller of the electric vehicle.
Alternatively, the determining unit that determines the first creep torque of the electric vehicle according to the vehicle speed and the brake pedal opening degree includes: determining a second creep torque of the electric vehicle according to the vehicle speed; determining a first creep torque of the electric vehicle according to the second creep torque and/or the brake pedal opening degree.
Optionally, the determining unit determining the first creep torque of the electric vehicle according to the second creep torque and/or the brake pedal opening degree includes: determining that the first creep torque is equal to the second creep torque when the brake pedal opening is 0; when the opening degree of the brake pedal is larger than or equal to a preset opening degree, determining that the first creep torque is 0; and when the opening degree of the brake pedal is smaller than a preset opening degree, calculating a first creep torque of the electric vehicle according to the second creep torque, the opening degree of the brake pedal and the preset opening degree.
Optionally, the determining unit calculating a first creep torque of the electric vehicle according to the second creep torque, the brake pedal opening degree, and the preset opening degree includes: determining a first creep torque of the electric vehicle according to the second creep torque, the opening degree of the brake pedal and the preset opening degree by using the following formula:
wherein T is the second creep torque, T' is the first creep torque, percent is the opening degree of the brake pedal, and P is the preset opening degree.
Yet another aspect of the invention provides a computer readable storage medium having stored thereon a computer program which, when executed by a processor, performs the steps of any of the methods described above.
In yet another aspect, the present invention provides a vehicle control unit for an electric vehicle, including a processor, a memory, and a computer program stored in the memory and operable on the processor, wherein the processor executes the computer program to implement the steps of any one of the methods.
The invention further provides a vehicle control unit of an electric vehicle, which comprises any one of the electric vehicle control devices.
According to the technical scheme of the invention, the output end of the motor and the transmission gear can be meshed in real time by adjusting the creep torque control, so that the condition of tooth beating vibration is avoided, the problems of tooth beating and electric vehicle shaking during starting and low-speed braking are solved, the service life of the gear is prolonged, and the driving experience is improved.
On the basis of the traditional crawling function scheme, a crawling control strategy is further optimized, namely when a certain brake opening degree exists, the crawling function of the VCU starts, a certain torque is output to the MCU, so that the motor output shaft gear and the transmission shaft gear are kept in a meshed state all the time, and the gear tooth beating and shaking phenomena are weakened or eliminated.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and not to limit the invention. In the drawings:
FIG. 1 is a method schematic diagram of an embodiment of an electric vehicle control method provided by the present invention;
FIG. 2 is a schematic diagram of gear tooth punching when a gear at the output end of the motor is in a non-meshing state with a gear of a transmission system;
FIG. 3 is a schematic view of the motor output gear in mesh with the transmission system gear;
FIG. 4 is a plot of torque versus brake pedal opening;
fig. 5 is a block diagram of an embodiment of an electric vehicle control device according to the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the specific embodiments of the present invention and the accompanying drawings. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
The invention provides a solution for controlling torque output of a Motor Controller (MCU) based on a control strategy of a Vehicle Control Unit (VCU), aiming at the phenomenon that a vehicle shakes due to backlash impact in the driving process of a new energy pure electric vehicle, and mainly applied to the conditions of starting of the pure electric vehicle and low-speed light-stepping brake braking.
For a pure electric vehicle, in order to simulate the idle starting function of a fuel vehicle in the related art, a crawling function is usually added to a VCU (vehicle control unit), namely, the vehicle crawls slowly by itself in a non-braking and non-accelerator state. When the vehicle enters a crawling state (the vehicle control unit VCU judges that a crawling condition is met, a torque instruction is sent to the motor controller MCU to drive the vehicle to slowly run), the VCU automatically adjusts the output torque according to the vehicle speed (through a PID control algorithm) and sends the output torque to the MCU, the torque sent by the VCU is usually slowly increased and has a certain delay, before the vehicle starts, the output torque of the VCU is small, and at the moment, a gear at the output end of the motor and a gear of a transmission system are in a non-meshing state, so that gear tooth punching and shaking phenomena may be caused (see fig. 2). In addition, the creep behavior is usually in a non-braking and non-accelerator state, when the vehicle slides slowly and lightly treads a brake at a low speed, the creep behavior is not in the creep state, the VCU has no torque output, the gear at the output end of the motor and the transmission shaft gear are in a free rotation state, and the gears are not meshed, so that the phenomena of gear beating and shaking can also be caused.
The invention provides an electric vehicle control method.
Fig. 1 is a method schematic diagram of an embodiment of a control method of an electric vehicle provided by the invention.
As shown in fig. 1, according to an embodiment of the present invention, the control method includes at least step S110, step S120, step S130, and step S140.
And step S110, judging whether to enter a crawling mode according to the current speed of the electric vehicle.
And step S120, if the electric vehicle is judged to enter the crawling mode, acquiring the current opening degree of a brake pedal of the electric vehicle.
Specifically, whether the crawling mode is entered or not is judged according to the current speed and the accelerator opening degree of the electric vehicle. And when the current speed of the electric vehicle is lower than a preset speed threshold and the opening degree of an accelerator pedal is 0, judging to enter a crawling mode. In the related technical scheme, the vehicle control unit VCU enters a crawling state when the vehicle speed is lower than a preset vehicle speed threshold (for example, 5km/h) and no brake or accelerator is provided according to the current vehicle speed of the electric vehicle and the signal states of a brake (brake pedal) and an accelerator (accelerator pedal). In the invention, when the current vehicle speed of the electric vehicle is lower than a preset vehicle speed threshold (for example, 5km/h) and the accelerator opening is 0, the creep mode is judged to be entered. For example, during a start with a brake pedal being depressed, a brake pedal being raised, or an accelerator pedal being depressed, the accelerator pedal is not actuated at the same time.
And step S130, determining a first creep torque of the electric vehicle according to the vehicle speed and the brake pedal opening degree.
In one embodiment, a second creep torque of the electric vehicle is determined based on the vehicle speed; determining a first creep torque of the electric vehicle according to the second creep torque and the brake pedal opening degree. The second creep torque, which is a creep torque in the related art that enters a creep state when the vehicle speed is lower than a preset vehicle speed threshold (e.g., 5km/h) and no braking and no accelerator are provided. Specifically, the rotating speed closed-loop control is carried out through a PID control algorithm to control the output torque, namely the second creep torque.
Wherein when the brake pedal opening is 0, it is determined that the first creep torque is equal to the second creep torque; when the opening degree of the brake pedal is larger than or equal to a preset opening degree, determining that the first creep torque is 0; and when the opening degree of the brake pedal is smaller than a preset opening degree, calculating a first creep torque of the electric vehicle according to the second creep torque, the opening degree of the brake pedal and the preset opening degree.
Specifically, when the brake pedal opening degree is smaller than a preset opening degree, a first creep torque of the electric vehicle is determined according to the second creep torque, the brake pedal opening degree and the preset opening degree by using the following formula:
wherein T is the second creep torque, T' is the first creep torque, percent is the brake pedal opening (the current real-time brake pedal opening), P is the preset opening, and the preset opening can be obtained by calibrating different vehicle types.
Specifically, since the magnitude of the brake opening (brake pedal opening) determines whether the vehicle is in a stationary state, when the brake opening is greater than P (0% < P < 100%), the vehicle is in a stationary state. When braking is present and the vehicle is in a static state, creep torque does not need to be output, so when the brake pedal opening degree is present, the creep output torque depends on the current brake pedal opening degree (percent), the distribution scheme is shown in the above formula, the relation between the first creep torque T 'and the brake pedal opening degree percent can be referred to fig. 4, and the first creep torque T' and the brake pedal opening degree percent are in a linear negative correlation.
When the current brake pedal opening degree (percentage) is smaller than P, creep torque is output, when the brake pedal opening degree is 0, creep torque T' is T, and when the brake pedal opening degree is larger than P, creep torque is 0. There is a linear relationship between brake pedal opening and creep torque.
Step S140, sending the first creep torque to a motor controller of the electric vehicle.
Specifically, after the first creep torque is obtained, the first creep torque is output to the motor controller, so that when a certain brake opening degree exists, the VCU creep function starts, a motor output shaft gear and a transmission shaft gear are kept in a meshed state all the time, and the gear tooth beating and shaking phenomena are reduced or eliminated.
In the related art, in a creeping state, under the conditions of no brake and no throttle entering the creeping state, the creeping output torque is assumed to be T (unit: N.m), T is a change value, the control strategy is speed closed-loop PI control based on the vehicle speed, and the torque output value is automatically adjusted according to the vehicle speed. In the technical scheme of the invention, on the basis of the creeping output torque T (second creeping torque) in the related technology, when the brake opening exists, the creeping output torque T' (first creeping torque) starts to be output, so that the motor output shaft gear and the transmission shaft gear are kept in a meshed state at any time, and the phenomena of gear tooth beating and shaking are reduced or eliminated.
According to the creep output torque control scheme, when the brake pedal is slightly stepped or lifted, and before the accelerator pedal does not act, the creep output torque enables the motor output shaft gear and the transmission shaft gear to be constantly in a meshed state (as shown in figure 3), and tooth beating or shaking caused by gear gaps is avoided. In conclusion, the creep output torque control scheme is changed, so that the gear does not generate large impact force, the gear is ensured to be in a meshing state at all times, the back-and-forth shake in the gear gap is eliminated, the controllability and the smoothness of the system are improved, the service life of the gear is prolonged, and the driving and riding comfort are improved.
The technical scheme of the invention is also suitable for the starting process of lightly stepping on the accelerator, before the accelerator pedal is stepped on, the VCU of the vehicle control unit controls and outputs a smaller torque, so that the gear of the output shaft of the motor and the gear of the transmission shaft are kept in a meshed state, and the phenomenon that the impact and the shake of the gear are caused by overlarge output torque after the accelerator is stepped on can be avoided.
The output scheme of the creep torque is optimized in the control process of the VCU, the relationship between the torque and the opening percentage of the brake pedal is established, when the brake is not completely released before the vehicle starts from a static state, the creep function starts, the VCU sends a corresponding creep torque signal to the MCU, the output end of the main drive motor is meshed with the axle gear, and therefore the problem that the vehicle shakes due to gear tooth beating is reduced and avoided.
The invention also provides a control device of the electric vehicle.
Fig. 5 is a block diagram of an embodiment of an electric vehicle control device according to the present invention. As shown in fig. 5, the electric vehicle control apparatus 100 includes a determination unit 110, an acquisition unit 120, a determination unit 130, and a control unit 140.
The judging unit 110 is used for judging whether to enter a crawling mode according to the current speed of the electric vehicle. The obtaining unit 120 is configured to obtain a current brake pedal opening degree of the electric vehicle if the determining unit 110 determines to enter the crawling mode.
Specifically, whether the crawling mode is entered or not is judged according to the current speed and the accelerator opening degree of the electric vehicle. And when the current speed of the electric vehicle is lower than a preset speed threshold and the opening degree of an accelerator pedal is 0, judging to enter a crawling mode. In the related technical scheme, the vehicle control unit VCU enters a crawling state when the vehicle speed is lower than a preset vehicle speed threshold (for example, 5km/h) and no brake or accelerator is provided according to the current vehicle speed of the electric vehicle and the signal states of a brake (brake pedal) and an accelerator (accelerator pedal).
In the invention, when the current vehicle speed of the electric vehicle is lower than a preset vehicle speed threshold (for example, 5km/h) and the accelerator opening (the accelerator opening is 0), the creep mode is judged to be entered. For example, during a start with a brake pedal being depressed or a brake pedal being lifted or an accelerator pedal being depressed, while the accelerator pedal is not actuated.
The determination unit 130 is configured to determine a first creep torque of the electric vehicle according to the vehicle speed and the brake pedal opening degree.
In one embodiment, a second creep torque of the electric vehicle is determined based on the vehicle speed; determining a first creep torque of the electric vehicle according to the second creep torque and/or the brake pedal opening degree. The second creep torque, which is a creep torque in the related art that enters a creep state when the vehicle speed is lower than a preset vehicle speed threshold (e.g., 5km/h) and no braking and no accelerator are provided. Specifically, the rotating speed closed-loop control is carried out through a PID control algorithm to control the output torque, namely the second creep torque.
Wherein, when the brake pedal opening degree is 0, it is determined that the first creep torque is equal to the second creep torque; when the opening degree of the brake pedal is larger than or equal to a preset opening degree, determining that the first creep torque is 0; and when the opening degree of the brake pedal is smaller than a preset opening degree, calculating a first creep torque of the electric vehicle according to the second creep torque, the opening degree of the brake pedal and the preset opening degree.
Specifically, when the brake pedal opening degree is smaller than a preset opening degree, a first creep torque of the electric vehicle is determined according to the second creep torque, the brake pedal opening degree and the preset opening degree by using the following formula:
wherein T is the second creep torque, T' is the first creep torque, percent is the brake pedal opening (the current real-time brake pedal opening), P is the preset opening, and the preset opening can be obtained by calibrating different vehicle types.
Specifically, since the magnitude of the brake opening (brake pedal opening) determines whether the vehicle is in a stationary state, when the brake opening is greater than P (0% < P < 100%), the vehicle is in a stationary state. When braking is present and the vehicle is in a static state, creep torque does not need to be output, so when the brake pedal opening degree is present, the creep output torque depends on the current brake pedal opening degree (percent), the distribution scheme is shown in the above formula, the relation between the first creep torque T 'and the brake pedal opening degree percent can be referred to fig. 4, and the first creep torque T' and the brake pedal opening degree percent are in a linear negative correlation.
When the current brake pedal opening degree (percent) is smaller than P, torque is output in creep, when the brake pedal opening degree is 0, creep torque T' is T, when the brake pedal opening degree is larger than P, creep torque is 0, and a linear relation exists between the brake pedal opening degree and the creep torque.
The control unit 140 is configured to send the first creep torque to a motor controller of the electric vehicle.
Specifically, after the first creep torque is obtained, the first creep torque is output to the motor controller, so that when a certain brake opening degree exists, the VCU creep function starts, a motor output shaft gear and a transmission shaft gear are kept in a meshed state all the time, and the gear tooth beating and shaking phenomena are reduced or eliminated.
In the related art, in a creeping state, under the conditions of no brake and no throttle entering the creeping state, the creeping output torque is assumed to be T (unit: N.m), T is a change value, the control strategy is speed closed-loop PI control based on the vehicle speed, and the torque output value is automatically adjusted according to the vehicle speed. In the technical scheme of the invention, on the basis of the creeping output torque T (second creeping torque) in the related technology, when the brake opening exists, the creeping output torque T' (first creeping torque) starts to be output, so that the motor output shaft gear and the transmission shaft gear are kept in a meshed state at any time, and the phenomena of gear tooth beating and shaking are reduced or eliminated.
According to the creep output torque control scheme, when the brake pedal is slightly stepped or lifted, and before the accelerator pedal does not act, the creep output torque enables the motor output shaft gear and the transmission shaft gear to be constantly in a meshed state (as shown in figure 3), and tooth beating or shaking caused by gear gaps is avoided. In conclusion, the creep output torque control scheme is changed, so that the gear does not generate large impact force, the gear is ensured to be in a meshing state at all times, the back-and-forth shake in the gear gap is eliminated, the controllability and the smoothness of the system are improved, the service life of the gear is prolonged, and the driving and riding comfort are improved.
The technical scheme of the invention is also suitable for the starting process of lightly stepping on the accelerator, before the accelerator pedal is stepped on, the VCU controls and outputs a smaller torque, so that the motor output shaft gear and the transmission shaft gear are kept in a meshed state, and the phenomenon that the output torque is too large after the accelerator is stepped on to cause gear impact jitter can be avoided.
The invention also provides a storage medium corresponding to the electric vehicle control method, on which a computer program is stored, which program, when executed by a processor, carries out the steps of any of the methods described above.
The invention also provides a vehicle control unit of an electric vehicle corresponding to the electric vehicle control method, which comprises a processor, a memory and a computer program stored on the memory and capable of running on the processor, wherein the processor realizes the steps of any one of the methods when executing the program.
The invention also provides a vehicle control unit of the electric vehicle corresponding to the electric vehicle control device, which comprises any one of the electric vehicle control devices.
Therefore, according to the scheme provided by the invention, on the basis of the traditional crawling function scheme, a crawling control strategy is further optimized, namely when a certain brake opening degree exists, the VCU crawling function starts to be started, and a certain torque is output to the MCU, so that the motor output shaft gear and the transmission shaft gear are kept in a meshed state all the time, and the phenomena of gear tooth beating and gear shaking are reduced or eliminated.
According to the creep output torque control scheme, when the brake pedal is slightly stepped or lifted, and before the accelerator pedal does not act, the creep output torque enables the motor output shaft gear and the transmission shaft gear to be constantly in a meshed state (as shown in fig. 3), and tooth beating or shaking caused by gear gaps is avoided.
In conclusion, the creep output torque control scheme is changed, so that the gear does not generate large impact force, the gear is ensured to be in a meshing state at all times, the back-and-forth shake in the gear gap is eliminated, the controllability and the smoothness of the system are improved, the service life of the gear is prolonged, and the driving and riding comfort are improved.
The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope and spirit of the invention and the following claims. For example, due to the nature of software, the functions described above may be implemented using software executed by a processor, hardware, firmware, hardwired, or a combination of any of these. In addition, each functional unit may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.
In the embodiments provided in the present application, it should be understood that the disclosed technology can be implemented in other ways. The above-described embodiments of the apparatus are merely illustrative, and for example, the division of the units may be a logical division, and in actual implementation, there may be another division, for example, multiple units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, units or modules, and may be in an electrical or other form.
The units described as separate parts may or may not be physically separate, and the parts serving as the control device may or may not be physical units, may be located in one place, or may be distributed on a plurality of units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.
The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention essentially or partly contributing to the related art or all or part of the technical solution may be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a removable hard disk, a magnetic or optical disk, and other various media capable of storing program codes.
The above description is only an example of the present invention, and is not intended to limit the present invention, and it is obvious to those skilled in the art that various modifications and variations can be made in the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.
Claims (10)
1. An electric vehicle control method characterized by comprising:
judging whether to enter a crawling mode according to the current speed of the electric vehicle;
if the electric vehicle is judged to enter the crawling mode, acquiring the current opening degree of a brake pedal of the electric vehicle;
determining a first creep torque of the electric vehicle according to the vehicle speed and the brake pedal opening degree;
sending the first creep torque to a motor controller of the electric vehicle.
2. The method of claim 1, wherein determining a first creep torque of the electric vehicle based on the vehicle speed and the brake pedal opening comprises:
determining a second creep torque of the electric vehicle according to the vehicle speed;
determining a first creep torque of the electric vehicle according to the second creep torque and/or the brake pedal opening degree.
3. The method of claim 2, wherein determining a first creep torque of the electric vehicle based on the second creep torque and/or the brake pedal opening comprises:
determining that the first creep torque is equal to the second creep torque when the brake pedal opening is 0;
when the opening degree of the brake pedal is larger than or equal to a preset opening degree, determining that the first creep torque is 0;
and when the opening degree of the brake pedal is smaller than a preset opening degree, calculating a first creep torque of the electric vehicle according to the second creep torque, the opening degree of the brake pedal and the preset opening degree.
4. The method of claim 3, wherein calculating a first creep torque of the electric vehicle based on the second creep torque, the brake pedal opening, and the preset opening comprises:
determining a first creep torque of the electric vehicle according to the second creep torque, the opening degree of the brake pedal and the preset opening degree by using the following formula:
wherein T is the second creep torque, T' is the first creep torque, percent is the opening degree of the brake pedal, and P is the preset opening degree.
5. An electric vehicle control apparatus, characterized by comprising:
the judging unit is used for judging whether to enter a crawling mode according to the current speed of the electric vehicle;
the obtaining unit is used for obtaining the current opening degree of a brake pedal of the electric vehicle if the judging unit judges that the electric vehicle enters the crawling mode;
the determining unit is used for determining a first creep torque of the electric vehicle according to the vehicle speed and the brake pedal opening degree;
a control unit to send the first creep torque to a motor controller of the electric vehicle.
6. The apparatus according to claim 5, wherein the determination unit determines a first creep torque of the electric vehicle according to the vehicle speed and the brake pedal opening degree, includes:
determining a second creep torque of the electric vehicle according to the vehicle speed;
determining a first creep torque of the electric vehicle according to the second creep torque and/or the brake pedal opening degree.
7. The apparatus according to claim 6, wherein the determining unit determines the first creep torque of the electric vehicle according to the second creep torque and/or the brake pedal opening degree, including:
determining that the first creep torque is equal to the second creep torque when the brake pedal opening is 0;
when the opening degree of the brake pedal is larger than or equal to a preset opening degree, determining that the first creep torque is 0;
and when the opening degree of the brake pedal is smaller than a preset opening degree, calculating a first creep torque of the electric vehicle according to the second creep torque, the opening degree of the brake pedal and the preset opening degree.
8. The apparatus according to claim 7, wherein the determination unit calculates a first creep torque of the electric vehicle according to the second creep torque, the brake pedal opening degree, and the preset opening degree, including:
determining a first creep torque of the electric vehicle according to the second creep torque, the opening degree of the brake pedal and the preset opening degree by using the following formula:
wherein T is the second creep torque, T' is the first creep torque, percent is the opening degree of the brake pedal, and P is the preset opening degree.
9. A storage medium, having stored thereon a computer program which, when being executed by a processor, carries out the steps of the method of any one of claims 1 to 4.
10. A vehicle control unit for an electric vehicle, comprising a processor, a memory and a computer program stored on the memory and executable on the processor, the processor implementing the steps of the method according to any one of claims 1 to 4 when executing the program, including the electric vehicle control device according to any one of claims 5 to 8.
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| CN202210301748.XA CN114633636A (en) | 2022-03-25 | 2022-03-25 | Electric vehicle control method and device, storage medium and vehicle control unit |
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| CN202210301748.XA CN114633636A (en) | 2022-03-25 | 2022-03-25 | Electric vehicle control method and device, storage medium and vehicle control unit |
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111169291A (en) * | 2018-11-09 | 2020-05-19 | 宝沃汽车（中国）有限公司 | Vehicle creep torque control method and device and vehicle |
| 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 |
| CN111942170A (en) * | 2019-05-16 | 2020-11-17 | 罗伯特·博世有限公司 | Vehicle creep control device and vehicle creep control method |
| CN112109711A (en) * | 2020-09-14 | 2020-12-22 | 恒大新能源汽车投资控股集团有限公司 | Vehicle creep control method and device, electronic equipment and storage medium |
| CN113335283A (en) * | 2021-06-17 | 2021-09-03 | 智新控制系统有限公司 | Control method and system for crawling with brake and computer readable storage medium |
-
2022
- 2022-03-25 CN CN202210301748.XA patent/CN114633636A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111169291A (en) * | 2018-11-09 | 2020-05-19 | 宝沃汽车（中国）有限公司 | Vehicle creep torque control method and device and vehicle |
| CN111942170A (en) * | 2019-05-16 | 2020-11-17 | 罗伯特·博世有限公司 | Vehicle creep control device and vehicle creep 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 |
| CN112109711A (en) * | 2020-09-14 | 2020-12-22 | 恒大新能源汽车投资控股集团有限公司 | Vehicle creep control method and device, electronic equipment and storage medium |
| CN113335283A (en) * | 2021-06-17 | 2021-09-03 | 智新控制系统有限公司 | Control method and system for crawling with brake and computer readable storage medium |
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