CN116330995A - Vehicle control method, device and system - Google Patents

Vehicle control method, device and system Download PDF

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Publication number
CN116330995A
CN116330995A CN202310619164.1A CN202310619164A CN116330995A CN 116330995 A CN116330995 A CN 116330995A CN 202310619164 A CN202310619164 A CN 202310619164A CN 116330995 A CN116330995 A CN 116330995A
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motor
voltage output
controller
speed
vehicle
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CN202310619164.1A
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CN116330995B (en
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李宇虹
张平化
孟凡己
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Fj Controlling Co ltd
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Fj Controlling Co 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
    • B60L15/28—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 without contact making and breaking, e.g. using a transductor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L7/00—Electrodynamic brake systems for vehicles in general
    • B60L7/24—Electrodynamic brake systems for vehicles in general with additional mechanical or electromagnetic braking
    • B60L7/26—Controlling the braking effect
    • 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
    • B60L2240/427—Voltage
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/60—Other road transportation technologies with climate change mitigation effect
    • Y02T10/72—Electric energy management in electromobility

Abstract

The invention discloses a vehicle control method, device and system. The vehicle control method includes: reducing a voltage output by the vehicle controller to the vehicle motor when the vehicle accelerator is released; if the current speed of the motor is within the preset range, or the voltage output to the motor by the controller is 0, the voltage output to the motor by the controller is gradually regulated according to the preset step value until the current speed of the motor is 0; the current speed is the duty ratio of the current rotating speed of the motor relative to the full rotating speed; the full rotation speed is the rotation speed of the motor when the voltage output by the controller to the motor is equal to the output voltage of the battery; and when the step-by-step regulating time of the voltage output to the motor reaches a first preset time, controlling the electromagnetic brake to be closed. According to the technical scheme, when the rotating speed of the motor is 0, the electromagnetic brake is closed, the problem of sudden braking or slipping is avoided, and the vehicle control precision is improved.

Description

Vehicle control method, device and system
Technical Field
The present invention relates to the field of vehicle control technologies, and in particular, to a vehicle control method, device, and system.
Background
With the rise of new energy, the development of electric scooter for the old age is faster and faster due to the general application of lithium battery.
But the electric scooter in the old age mostly adopts a low-voltage direct current motor to drive as a whole vehicle, so that cost is saved, a speed sensor is not adapted to the motor, and speed closed-loop control cannot be performed, so that electromagnetic braking cannot be controlled according to the speed of the vehicle, and the problem of sudden braking or backward sliding easily occurs when the ramp is parked, so that user experience is poor.
Disclosure of Invention
The invention provides a vehicle control method, device and system, which are used for solving the problem that sudden braking or backward sliding is easy to occur when a ramp is parked.
According to an aspect of the present invention, there is provided a vehicle control method including:
reducing a voltage output by the vehicle controller to the vehicle motor when the vehicle accelerator is released;
if the current speed of the motor is within a preset range or the voltage output by the controller to the motor is 0, the voltage output by the controller to the motor is gradually regulated according to a preset step value until the current speed of the motor is 0; wherein the current speed is the duty ratio of the current rotating speed of the motor relative to the full rotating speed; the full rotation speed is the rotation speed of the motor when the voltage output to the motor by the controller is equal to the output voltage of the battery;
and when the step-by-step regulating time of the voltage output to the motor reaches a first preset time, controlling the electromagnetic brake to be closed.
Optionally, after controlling the electromagnetic brake to be closed, the method further comprises:
and when the closing time of the electromagnetic brake reaches a second preset time, controlling the voltage output to the motor to be 0.
Optionally, controlling the voltage output to the motor to be 0 includes:
reducing the voltage output duty ratio according to a first preset curve to reduce the voltage output by the controller to the motor until the voltage output by the controller to the motor is 0; wherein the voltage output duty cycle is a duty cycle of a voltage output to the motor by the controller relative to a battery output voltage.
Optionally, after the voltage output to the motor is 0, the method further includes:
if the accelerator is started, determining a target voltage output to a motor by the controller according to the state of the accelerator;
lifting the voltage output duty cycle according to a second preset curve until the voltage output duty cycle reaches a starting compensation duty cycle; the voltage output duty ratio is the duty ratio of the voltage output by the controller to the motor relative to the output voltage of the battery;
disconnecting the electromagnetic brake;
adjusting the voltage output duty cycle to a target duty cycle; wherein the target duty cycle is a duty cycle of the target voltage with respect to the battery output voltage.
Optionally, if the current speed of the motor is within the preset range, the step-by-step adjustment of the voltage output by the controller to the motor according to the preset step-size value until the current speed of the motor is 0, further includes:
and when the current speed is 0, the voltage output duty ratio output by the controller is used as the starting compensation duty ratio.
Optionally, step-by-step adjusting the voltage output to the motor according to a preset step value, including:
determining the preset step value according to the current speed of the motor;
if the current speed of the motor is greater than 0, subtracting a preset step value from the current voltage output duty ratio; the voltage output duty ratio is the duty ratio of the voltage output by the controller to the motor relative to the output voltage of the battery;
and if the current speed of the motor is smaller than 0, adding the preset step value to the current voltage output duty ratio.
Optionally, after reducing the voltage output by the vehicle controller to the vehicle motor when the vehicle accelerator is released, further comprising:
a current speed of the motor is calculated.
Optionally, calculating the current speed of the motor includes:
acquiring an output voltage value of the controller and a current value of the motor;
determining a back electromotive force according to an output voltage value of the controller and a current value of the motor;
and taking the product of the back electromotive force and a preset coefficient as the current speed of the motor.
According to another aspect of the present invention, there is provided a vehicle control apparatus for performing the vehicle control method according to any embodiment of the present invention;
the vehicle control device includes:
a first control module for reducing a voltage output by the vehicle controller to the vehicle motor when the vehicle accelerator is released;
the adjusting module is used for gradually adjusting the voltage output to the motor by the controller according to a preset step value until the current speed of the motor is 0 if the current speed of the motor is in a preset range or the voltage output to the motor by the controller is 0; wherein the current speed is the duty ratio of the current rotating speed of the motor relative to the full rotating speed; the full rotation speed is the rotation speed of the motor when the voltage output to the motor by the controller is equal to the output voltage of the battery;
and the second control module is used for controlling the electromagnetic brake to be closed when the step-by-step adjustment time length of the voltage output to the motor reaches a first preset time length.
According to another aspect of the present invention, there is provided a vehicle control system including: accelerator, motor, electromagnetic brake, battery and controller; the controller comprises the vehicle control device provided by any embodiment of the invention;
the accelerator is connected with the controller, and the controller is used for acquiring the state of the accelerator so as to determine whether the accelerator is released or not;
the output end of the battery is connected with the controller, the controller is connected with the motor, and the controller is used for reducing the voltage output by the controller to the motor when the accelerator is released; if the current speed of the motor is within a preset range or the voltage output to the motor by the controller is 0, the voltage output to the motor by the controller is gradually regulated according to a preset step value until the current speed of the motor is 0; wherein the current speed is a duty cycle of a current rotational speed of the motor to a ratio relative to a full rotational speed; the full rotation speed is the rotation speed of the motor when the voltage output to the motor by the controller is equal to the output voltage of the battery;
the electromagnetic brake is connected with the controller, and the controller is further used for controlling the electromagnetic brake to be closed when the time length of regulating the voltage output to the motor reaches a first preset time length.
According to another aspect of the present invention, there is provided a vehicle comprising the vehicle control system according to any of the embodiments of the present invention.
According to the technical scheme, when the vehicle accelerator is released, the voltage output by the controller to the vehicle motor is reduced, if the current speed of the motor is in the preset range, the current speed is smaller, and the vehicle is in an ascending state, at the moment, the controller starts the other control module (the adjusting module) in the vehicle accelerator to adjust the voltage output duty ratio because the reduction speed of the voltage output duty ratio is smaller, so that the rotating speed of the motor is adjusted until the current speed of the motor is 0, the rotating speed of the motor is conveniently pulled down as soon as possible, and the response speed of the system is improved. Or if the voltage output duty cycle of the controller is 0, that is, the voltage output to the motor by the controller is 0, the vehicle is indicated to be in a downhill state. On downhill, the vehicle will move downward, i.e. the motor speed will not be 0, even if the voltage output duty cycle of the controller is 0. At this time, the controller starts another control module (adjusting module) inside it to adjust the voltage output duty ratio, thereby adjusting the motor rotation speed until the current speed of the motor is 0. Therefore, when the rotating speed of the motor is 0, the electromagnetic brake is conveniently closed, the problem of sudden braking or slipping down is avoided, and the control precision of the vehicle is improved.
It should be understood that the description in this section is not intended to identify key or critical features of the embodiments of the invention or to delineate the scope of the invention. Other features of the present invention will become apparent from the description that follows.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a flow chart of a vehicle control method provided by an embodiment of the present invention;
FIG. 2 is a flow chart of yet another vehicle control method provided by an embodiment of the present invention;
FIG. 3 is a flow chart of yet another vehicle control method provided by an embodiment of the present invention;
fig. 4 is a schematic structural view of a vehicle control apparatus according to an embodiment of the present invention;
fig. 5 is a schematic structural diagram of a vehicle control system according to an embodiment of the present invention.
Detailed Description
In order that those skilled in the art will better understand the present invention, a technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, shall fall within the scope of the present invention.
It should be noted that the terms "first," "second," and the like in the description and the claims of the present invention and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the invention described herein may be implemented in sequences other than those illustrated or otherwise 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 electric scooter adopts a low-voltage direct current motor to drive the whole scooter, but a speed sensor is not adapted to the motor, so that the motor rotating speed cannot be detected in real time, and the electromagnetic brake cannot be controlled according to the motor rotating speed. When the electric scooter parks on a slope, if the motor rotating speed is high, for example, the motor rotating speed is higher than 0, the electromagnetic brake is controlled to be closed at the moment, so that the problem of sudden braking can be caused; or when the rotating speed of the motor is less than 0, the electromagnetic brake is controlled to be closed, namely after the vehicle slides backwards for a certain period, the electromagnetic brake is controlled to be closed, and the vehicle has the problem of backward sliding; both of the above results in a poor user experience.
In view of the above technical problems, the present embodiment provides a vehicle control method. Fig. 1 is a flowchart of a vehicle control method according to an embodiment of the present invention, as shown in fig. 1, the method includes:
s110, when the vehicle accelerator is released, reducing the voltage output to the vehicle motor by the vehicle controller.
The vehicle comprises an electric scooter, for example, the electric scooter comprises a battery, a controller and a motor, and the battery supplies power for the motor through the controller. The controller can control the voltage output to the motor by adjusting the voltage output duty cycle, and the voltage output to the motor is the product of the battery output voltage and the voltage output duty cycle. The vehicle further includes an accelerator, for example, an accelerator pedal, which may be a rotatable handlebar, or a button, or other structures, on the electric scooter. The controller is connected with the accelerator, and when the vehicle runs, the controller determines the voltage output duty ratio according to the stroke of the accelerator pedal (namely the depth of the accelerator pedal being stepped on), or determines the voltage output duty ratio according to the rotation degree of the handlebar, or determines the voltage output duty ratio according to the push degree of the button (or the position of the button), so that the voltage output to the motor is determined, the motor rotates according to the target rotating speed, and the vehicle runs according to the target speed.
Specifically, the vehicle accelerator is released, for example, one of no pressure on the accelerator pedal, the depth to which the accelerator pedal is depressed is 0, the handle turning stroke is 0, or the handle turning angle is 0, but may be other forms. If the controller detects that the vehicle accelerator is released, the user is indicated to park, the controller reduces the voltage output duty ratio, so that the voltage output by the controller to the motor is reduced, the motor rotating speed is reduced, the vehicle speed is reduced, and the vehicle is convenient to park.
S120, judging whether the current speed of the motor is within a preset range or not, or whether the voltage output to the motor by the controller is 0 or not, if so, executing a step S130; if not, the process returns to step S110.
S130, gradually adjusting the voltage output to the motor by the controller according to a preset step value until the current speed of the motor is 0; the current speed is the duty ratio of the current rotating speed of the motor relative to the full rotating speed; the full rotation speed is the rotation speed of the motor when the voltage output to the motor by the controller is equal to the output voltage of the battery.
Specifically, after the controller starts to reduce the voltage output to the motor, the controller starts to calculate the current speed of the motor, for example, in real time, or may calculate at intervals, preferably, after the controller starts to reduce the voltage output to the motor, the controller calculates the current speed of the motor in real time. After the current speed of the motor is calculated, comparing the current speed of the motor with a preset range, and if the current speed of the motor is within the preset range, indicating that the current speed is smaller, the vehicle is in an uphill state. Because the speed of the decrease in vehicle speed (motor speed) is greater than the speed of the decrease in voltage output duty cycle of the controller due to gravity factors when ascending a slope. At this time, since the speed of decreasing the voltage output duty ratio is smaller, the controller starts another control module (adjusting module) inside the controller to adjust the voltage output duty ratio, so as to adjust the motor speed until the current speed of the motor is 0, so that the motor speed is conveniently pulled down as soon as possible, and the response speed of the system is improved. Therefore, when the rotating speed of the motor is 0, the electromagnetic brake is conveniently closed, the problem of sudden braking or slipping down is avoided, and the control precision of the vehicle is improved.
After the controller starts to reduce the voltage output to the motor, the duty ratio of the voltage output from the controller to the motor is determined, and if the duty ratio of the voltage output from the controller is 0, that is, the voltage output from the controller to the motor is 0 (or close to 0, for example, 0.0001 or 0.001), the vehicle is indicated to be in a downhill state. Because the vehicle is in a downhill state, the vehicle speed decreases at a speed less than the voltage output duty cycle of the controller due to the weight of the vehicle. On downhill, the vehicle will move downward, i.e. the motor speed will not be 0, even if the voltage output duty cycle of the controller is 0. At this time, the controller starts another control module (adjusting module) in the controller to adjust the duty ratio of the voltage output, so as to adjust the rotating speed of the motor until the current speed of the motor is 0, so that the electromagnetic brake is conveniently closed when the rotating speed of the motor is 0, the problem of sudden braking or slipping down is avoided, and the control precision of the vehicle is improved.
And the voltage output to the motor by the controller is regulated step by step according to the preset step value, so that the rotation speed of the motor is reduced more gradually, the vibration is reduced, and the smooth stability of the vehicle is maintained. And the current speed of the primary motor can be judged by adjusting the voltage output to the motor by the controller every time, and the current speed of the motor after adjustment is 0.
The preset step value is the duty ratio of the rotating speed adjusted each time relative to the full rotating speed. The preset step value is preset, for example, and is stored in the controller. The preset step value may be one, two or a plurality of. The controller selects a corresponding preset step value according to the current rotating speed of the motor, for example, when the current speed of the motor is high, the controller selects the largest preset step value in all stored preset step values, so that the adjusting speed can be increased, the rotating speed of the motor can be reduced as soon as possible, and the system response is improved; when the current speed of the motor is smaller, the smallest preset step value in all stored preset step values is selected, so that excessive adjustment can be avoided, smooth reduction of the rotating speed of the motor is ensured, and smooth stability of the vehicle is maintained; when the current speed of the motor is equal, the medium preset step value in all stored preset step values is selected, so that the overshoot can be avoided while the adjustment speed is increased.
And S140, controlling the electromagnetic brake to be closed when the step-by-step adjustment time of the voltage output to the motor reaches a first preset time.
Specifically, the first preset time period is longer than a time period from the start of stepwise adjustment of the motor output to the motor to the current speed of the motor being 0. The step-by-step adjustment of the motor output to the motor is started while the timing is started, and when the step-by-step adjustment duration of the voltage output to the motor reaches a first preset duration, the current speed of the motor has been adjusted to 0 and delayed for a certain period of time. Therefore, the current speed of the motor can be guaranteed to be regulated to 0, the current speed of the motor, which is caused by the inertia of the whole vehicle, the wind speed or other factors, is prevented from being 0, the current speed of the motor is prevented from being changed after wind stops, misjudgment is avoided, and the accuracy of vehicle control is improved. Therefore, when the step-by-step regulation duration of the voltage output to the motor reaches the first preset duration, the electromagnetic brake is controlled to be closed, so that the battery brake can be closed when the current speed of the motor is 0, and the problem of sudden braking or slipping down is prevented. When the electromagnetic brake is closed, the vehicle is braked, and the vehicle is ensured to be stopped on the ramp.
According to the technical scheme, when the vehicle accelerator is released, the voltage output to the vehicle motor by the controller is reduced, if the current speed of the motor is within the preset range, the current speed is smaller, and the vehicle is in an ascending state, at the moment, the controller starts the other control module (the adjusting module) inside the controller to adjust the voltage output duty ratio due to the smaller speed of the voltage output duty ratio, so that the rotating speed of the motor is adjusted until the current speed of the motor is 0, the rotating speed of the motor is conveniently pulled down as soon as possible, and the response speed of the system is improved. Or if the voltage output duty cycle of the controller is 0, that is, the voltage output to the motor by the controller is 0, the vehicle is indicated to be in a downhill state. On downhill, the vehicle will move downward, i.e. the motor speed will not be 0, even if the voltage output duty cycle of the controller is 0. At this time, the controller starts another control module (adjusting module) inside it to adjust the voltage output duty ratio, thereby adjusting the motor rotation speed until the current speed of the motor is 0. Therefore, when the rotating speed of the motor is 0, the electromagnetic brake is conveniently closed, the problem of sudden braking or slipping down is avoided, and the control precision of the vehicle is improved.
After the electromagnetic brake is released (electromagnetic brake is closed), the voltage output to the motor needs to be controlled to be 0, the force for maintaining the vehicle in a slope is transferred from the motor to the electromagnetic brake, and the vehicle control method is described below with respect to this transfer process, but the present application is not limited thereto.
Fig. 2 is a flowchart of yet another vehicle control method according to an embodiment of the present invention, optionally, referring to fig. 2, the vehicle control method includes:
s210, when the vehicle accelerator is released, reducing the voltage output to the vehicle motor by the vehicle controller.
S220, judging whether the current speed of the motor is within a preset range or not, or whether the voltage output to the motor by the controller is 0 or not, if so, executing step S230; if not, the process returns to step S210.
S230, gradually adjusting the voltage output to the motor by the controller according to a preset step value until the current speed of the motor is 0; the current speed is the duty ratio of the current rotating speed of the motor relative to the full rotating speed; the full rotation speed is the rotation speed of the motor when the voltage output to the motor by the controller is equal to the output voltage of the battery.
And S240, controlling the electromagnetic brake to be closed when the step-by-step adjustment time of the voltage output to the motor reaches a first preset time.
S250, controlling the voltage output to the motor to be 0 when the closing time of the electromagnetic brake reaches a second preset time.
Specifically, by delaying the second preset time period to ensure that the force for maintaining the vehicle in a slope is transferred from the motor to the electromagnetic brake, and then controlling the voltage output to the motor to be 0 (i.e. controlling the motor not to run any more), the motor can be released after the electromagnetic brake is braked. And when the closing time of the electromagnetic brake does not reach the second preset time, controlling the voltage output to the motor to be unchanged. Therefore, the voltage output to the motor is controlled to be 0 before the electromagnetic brake is not braked, so that the vehicle is prevented from running down, and the reliability of vehicle control is improved.
Optionally, controlling the voltage output to the motor to be 0 includes:
reducing the voltage output duty ratio according to a first preset curve to reduce the voltage output by the controller to the motor until the voltage output by the controller to the motor is 0; wherein the voltage output duty cycle is the duty cycle of the voltage output by the controller to the motor relative to the battery output voltage.
Specifically, the first preset curve is, for example, a linear curve, that is, a linear decreasing voltage output duty ratio, and linearly decreases the voltage output to the motor until the voltage output to the motor by the controller is 0, so that the motor rotation speed gradually decreases until the motor stops rotating. In other embodiments, the first preset curve may also be a non-linear curve, for example, the voltage output duty cycle decreases rapidly and then decreases slowly, so that the motor speed decreases rapidly and then decreases slowly. Therefore, when the motor rotation speed is high, the motor rotation speed can be quickly reduced, and the response rate of the system is improved; when the motor rotation speed is smaller, the motor rotation speed is slowly reduced, overshoot is avoided, smoothness can be further improved, and the reliability of vehicle control is further improved.
For example, the decreasing time of the voltage output duty ratio may be set, and the voltage output duty ratio is gradually decreased in the decreasing time according to the ratio of the corresponding voltage output duty ratio to the decreasing time when the electromagnetic brake is closed, so as to linearly decrease the voltage output duty ratio. For example, the decreasing time is set to be Td, and the corresponding voltage output duty ratio is set to be P when the electromagnetic brake is closed m1 Each time the reduced voltage output duty cycle is
Figure SMS_1
。
After the hill-hold is completed, the user may restart the vehicle, and the vehicle control method is described below in connection with the hill-hold process, but is not limited to this application.
On the basis of the above embodiments, fig. 3 is a flowchart of yet another vehicle control method provided by an embodiment of the present invention, optionally, referring to fig. 3, the vehicle control method includes:
s310, when the vehicle accelerator is released, reducing the voltage output to the vehicle motor by the vehicle controller.
S320, judging whether the current speed of the motor is within a preset range or not, or whether the voltage output to the motor by the controller is 0 or not, if so, executing step S330; if not, the process returns to step S310.
S330, gradually adjusting the voltage output to the motor by the controller according to a preset step value until the current speed of the motor is 0; the current speed is the duty ratio of the current rotating speed of the motor relative to the full rotating speed; the full rotation speed is the rotation speed of the motor when the voltage output to the motor by the controller is equal to the output voltage of the battery.
And S340, controlling the electromagnetic brake to be closed when the step-by-step adjustment time of the voltage output to the motor reaches a first preset time.
And S350, controlling the voltage output to the motor to be 0 when the closing time of the electromagnetic brake reaches a second preset time.
And S360, if the accelerator is started, determining a target voltage output to the motor by the controller according to the state of the accelerator.
Specifically, the controller detects that the vehicle accelerator is activated, indicating that the user is to restart the vehicle. The state of the accelerator includes the stroke of the accelerator, i.e., the depth to which the accelerator pedal is depressed, or the degree to which the handle rotates, or the degree to which the button is depressed, or the position at which the button is located, etc. The controller determines a voltage output duty cycle based on a state of the vehicle accelerator to thereby determine a target voltage output to the motor such that the motor rotates at a desired target speed of the vehicle.
S370, lifting the voltage output duty ratio according to a second preset curve until the voltage output duty ratio reaches the starting compensation duty ratio; wherein the voltage output duty cycle is the duty cycle of the voltage output by the controller to the motor relative to the battery output voltage.
Specifically, the second preset curve is, for example, a linear curve, i.e., linearly increases to the voltage output duty cycle until the voltage output duty cycle reaches the start-up compensation duty cycle. The starting compensation duty ratio is a voltage output duty ratio corresponding to a voltage required by the motor when the motor generates a starting compensation torque, and the starting compensation torque is a torque generated by the motor when the vehicle is balanced to slide down due to gravity. Thus, when the voltage output duty cycle reaches the start-up compensation duty cycle, it can be ensured that the torque generated by the motor is sufficient to maintain the force of the vehicle on a hill.
For example, a boost time of the voltage output duty cycle may be set, and the voltage output duty cycle is gradually boosted in the boost time according to a ratio of the start compensation duty cycle to the boost time, so as to realize a linear boost voltage output duty cycle. For example, the rise time is set to Ta, and the start-up compensation duty cycle is set to P m2 The duty cycle of the voltage output per boost is
Figure SMS_2
。
S380, switching off the electromagnetic brake.
Specifically, after the voltage output duty ratio reaches the starting compensation duty ratio, the electromagnetic brake is disconnected, so that the electromagnetic brake is disconnected when the motor can maintain the vehicle to stay on a slope. Therefore, the electromagnetic brake is ensured to be disconnected after the force for maintaining the parking of the electromagnetic brake is transferred to the motor, the phenomenon that the vehicle slides downwards can be avoided, and the reliability of vehicle control is improved.
S390, adjusting the voltage output duty cycle to a target duty cycle; wherein the target duty cycle is a duty cycle of the target voltage relative to the battery output voltage.
Specifically, after the force for maintaining the parking slope is transferred from the electromagnetic brake to the motor, the voltage output duty ratio is adjusted to the target duty ratio, so that the voltage output to the motor by the controller reaches the target voltage, the rotating speed of the motor is matched with the formation of the accelerator, and the vehicle runs at the target speed expected by a user.
On the basis of the above technical solutions, optionally, if the current speed of the motor is within the preset range, the step-by-step adjustment of the voltage output by the controller to the motor according to the preset step value is further included after the current speed of the motor is 0:
when the current speed is 0, the voltage output duty ratio output by the controller is used as the starting compensation duty ratio.
Specifically, if the current speed of the motor is within the preset range, the current speed is smaller, and the vehicle is in an uphill state. Because the speed of the decrease in vehicle speed (motor speed) is greater than the speed of the decrease in voltage output duty cycle of the controller due to gravity factors when ascending a slope. The voltage output duty cycle does not decrease to 0 when ascending a slope, so when the current speed of the motor is 0 when ascending a slope, the voltage output duty cycle output by the controller is used as the starting compensation duty cycle. When the current speed of the motor is 0 in an ascending slope, the voltage output by the controller to the motor is converted into a torque for maintaining the ascending slope, so that the corresponding voltage output duty ratio when the current speed of the motor is 0 is used as a starting compensation duty ratio, and the starting compensation duty ratio is sufficient for maintaining the ascending slope.
As a further implementation manner of the embodiment, on the basis of the foregoing technical solutions, optionally, step-adjusting the voltage output to the motor according to a preset step value includes:
step a1, determining a preset step value according to the current speed of the motor.
Specifically, the preset step values are preset, for example, two preset step values, one larger and one smaller, for example. When the current speed of the motor is slightly higher, a larger preset step value can be selected, so that the output speed of the motor moment is increased, the system response is improved, the motor rotating speed is reduced as soon as possible, and the rapid parking is facilitated. When the current speed of the motor is smaller, a smaller preset step value can be selected, the compensation speed is reduced, overshoot of the system is avoided, vibration is reduced, smooth stability of the vehicle is maintained, and reliability of vehicle control is improved. The preset step value Voft includes, for example, a larger value voft_max and a smaller value voft_min. When the current speed of the motor is slightly higher, a larger preset step value may be selected, i.e. voft=voft_max; when the current speed of the motor is slightly smaller, a smaller preset step value, namely voft=voft_min, can be selected, so that different preset step values are selected according to different current speeds, and the selected preset step values meet requirements.
Step a2, if the current speed of the motor is greater than 0, subtracting a preset step value from the current voltage output duty ratio; wherein the voltage output duty cycle is the duty cycle of the voltage output by the controller to the motor relative to the battery output voltage.
Specifically, when the current speed of the motor is greater than 0, the preset step value is subtracted from the current voltage output duty ratio, so that the voltage output duty ratio is reduced, namely the voltage output to the motor by the controller is reduced, the current speed of the motor tends to 0 until the current speed of the motor is 0, the motor is conveniently stopped when the current speed of the motor is 0, and the condition of slipping or sudden braking is avoided.
And a3, if the current speed of the motor is smaller than 0, adding a preset step value to the current voltage output duty ratio.
Specifically, when the current speed of the motor is smaller than 0, the current voltage output duty ratio is increased by adding the preset step value, namely, the voltage output by the controller to the motor is increased, so that the current speed of the motor tends to 0 until the current speed of the motor is 0, the motor is conveniently stopped when the current speed of the motor is 0, and the condition of slipping or sudden braking is avoided.
The following describes a manner of calculating the current speed of the vehicle motor, but is not a limitation of the present application.
On the basis of the above aspects, optionally, after reducing the voltage output from the vehicle controller to the vehicle motor when the vehicle accelerator is released, the method further includes:
the current speed of the motor is calculated.
Specifically, after the controller starts to reduce the voltage output to the motor, the controller starts to calculate the current speed of the motor, for example, in real time, so that the voltage output to the motor is adjusted according to the current speed of the motor in real time, the current speed of the motor is conveniently adjusted to 0, and overshoot can be avoided.
Optionally, calculating the current speed of the vehicle motor includes:
and b1, acquiring an output voltage value of the controller and a current value of the motor.
Specifically, for example, a current transformer, a current sensor, or the like is used to collect the current value of the motor, and the output voltage of the vehicle controller is the voltage output to the motor by the controller. The current speed of the motor is conveniently calculated by acquiring the output voltage value of the vehicle controller and the current value of the motor.
And b2, determining back electromotive force according to the output voltage value of the controller and the current value of the motor.
In particular, however, the electric energy corresponding to the electromotive force is converted into mechanical energy, i.e., into energy of rotation of the motor, and thus the motor speed can be characterized according to the back electromotive force. Illustratively, the output voltage value of the vehicle controller is U, the current value of the motor is I, the internal resistance of the motor is R, and the counter electromotive force e=u-IR. The internal resistance R of the motor may be measured in advance, or may be detected by the controller, and the embodiment is not limited thereto.
And b3, taking the product of the back electromotive force and a preset coefficient as the current speed of the motor.
Specifically, the back electromotive force is in a linear relationship with the current speed of the motor, and a preset coefficient between the back electromotive force and the current speed of the motor is calculated in advance, for example. For example, before leaving the factory, the rotating speed of the motor is collected for many times, the counter electromotive force corresponding to each rotating speed is calculated, and the linear relation between the counter electromotive force and the rotating speed is obtained, so that the preset coefficient is calculated. And the preset coefficient includes, for example, the full rotation speed (the rotation speed of the motor when the voltage output to the motor by the controller is equal to the battery output voltage), the current speed is not the current rotation speed of the motor, but the duty ratio of the current rotation speed to the full rotation speed. Therefore, the technical scheme of the embodiment can control the vehicle without calculating the motor rotation speed. For example, if the preset coefficient is, for example, P, the current speed Vm of the motor=p×e. Therefore, according to the current speed of the motor, the voltage output to the motor is regulated according to the current speed of the motor in real time, the current speed of the motor is conveniently regulated to 0, and overshoot can be avoided.
The technical solution of the present embodiment further provides a vehicle control device, and fig. 4 is a schematic structural diagram of the vehicle control device provided by the embodiment of the present invention, and as shown in fig. 4, the vehicle control device is used to execute the vehicle control method provided by any of the foregoing embodiments, and the controller includes the vehicle control device. The vehicle control device includes: a first control module 410, an adjustment module 420, and a second control module 430; the first control module 410 is configured to reduce a voltage output by the vehicle controller to the vehicle motor when the vehicle accelerator is released; the adjusting module 420 is configured to adjust the voltage output from the controller to the motor step by step according to a preset step value until the current speed of the motor is 0 if the current speed of the motor is within a preset range or the voltage output from the controller to the motor is 0; the current speed is the duty ratio of the current rotating speed of the motor relative to the full rotating speed; the full rotation speed is the rotation speed of the motor when the voltage output by the controller to the motor is equal to the output voltage of the battery; the second control module 430 is configured to control the electromagnetic brake to be closed when a step-by-step adjustment duration of the voltage output to the motor reaches a first preset duration.
The vehicle control device provided by the embodiment of the invention can execute the vehicle control method provided by any embodiment of the invention, and has the corresponding functional modules and beneficial effects of the execution method.
The technical solution of the present embodiment further provides a vehicle control system, and fig. 5 is a schematic structural diagram of the vehicle control system provided in the embodiment of the present invention, as shown in fig. 5, a vehicle control system accelerator 510, a motor 520, an electromagnetic brake 530, a battery 540 and a controller 550; the controller 550 includes the vehicle control apparatus provided by any of the embodiments of the present invention; the accelerator 510 is connected to the controller 550, and the controller 550 is configured to acquire a state of the accelerator 510 to determine whether the accelerator 510 is released; the output of the battery 540 is connected to the controller 550, the controller 550 is connected to the motor 520, and the controller 550 is configured to reduce the voltage output from the controller 550 to the motor 520 when the accelerator 510 is released; if the current speed of the motor 520 is within the preset range, or the voltage output from the controller 550 to the motor 520 is 0, the voltage output from the controller 550 to the motor 520 is gradually adjusted according to the preset step value until the current speed of the motor 520 is 0; wherein the current speed is the duty cycle of the current rotational speed of the motor to the ratio relative to full rotational speed; the full rotation speed is the rotation speed of the motor 520 when the voltage output to the motor 520 by the controller 550 is equal to the battery output voltage; the electromagnetic brake 530 is connected to the controller 550, and the controller 550 is further configured to control the electromagnetic brake 530 to be closed when a duration of adjusting the voltage output to the motor 520 reaches a first preset duration.
Thus, when the user stops, the accelerator 510 is released, the controller 550 detects that the accelerator 510 is released, the controller 550 reduces the voltage output to the motor 520, if the current speed of the motor 520 is within the preset range, the current speed is smaller, and the vehicle is in an uphill state, at this time, the controller 550 starts another control module (adjusting module) inside the vehicle to adjust the voltage output duty ratio due to the smaller speed of the voltage output duty ratio, so as to adjust the motor rotation speed until the current speed of the motor 520 is 0, so as to facilitate pulling down the motor rotation speed as soon as possible and improve the response speed of the system. Alternatively, if the voltage output duty cycle of the controller 550 is 0, i.e., the voltage output by the controller 550 to the motor is 0, it indicates that the vehicle is in a downhill state. On a downhill slope, the vehicle will still move downward, i.e. the motor speed will not be 0, even if the voltage output duty cycle of the controller 550 is 0. At this time, the controller 550 starts another control module (adjusting module) inside thereof to adjust the voltage output duty ratio, thereby adjusting the motor rotation speed until the current speed of the motor 520 is 0. Thus, when the rotating speed of the motor 520 is 0, the electromagnetic brake 530 is conveniently closed, the problem of sudden braking or slipping down is avoided, and the vehicle control precision is improved.
The technical scheme of the embodiment also provides a vehicle, which comprises the vehicle control system provided by any embodiment. Therefore, the vehicle control system provided by any embodiment of the present invention has the same beneficial effects, and will not be described herein.
It should be appreciated that various forms of the flows shown above may be used to reorder, add, or delete steps. For example, the steps described in the present invention may be performed in parallel, sequentially, or in a different order, so long as the desired results of the technical solution of the present invention are achieved, and the present invention is not limited herein.
The above embodiments do not limit the scope of the present invention. It will be apparent to those skilled in the art that various modifications, combinations, sub-combinations and alternatives are possible, depending on design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of the present invention.

Claims (10)

1. A vehicle control method characterized by comprising:
reducing a voltage output by the vehicle controller to the vehicle motor when the vehicle accelerator is released;
if the current speed of the motor is within a preset range or the voltage output by the controller to the motor is 0, the voltage output by the controller to the motor is gradually regulated according to a preset step value until the current speed of the motor is 0; wherein the current speed is the duty ratio of the current rotating speed of the motor relative to the full rotating speed; the full rotation speed is the rotation speed of the motor when the voltage output to the motor by the controller is equal to the output voltage of the battery;
and when the step-by-step regulating time of the voltage output to the motor reaches a first preset time, controlling the electromagnetic brake to be closed.
2. The method of claim 1, further comprising, after controlling the electromagnetic brake to close:
and when the closing time of the electromagnetic brake reaches a second preset time, controlling the voltage output to the motor to be 0.
3. The method of claim 2, wherein controlling the voltage output to the motor to be 0 comprises:
reducing the voltage output duty ratio according to a first preset curve to reduce the voltage output by the controller to the motor until the voltage output by the controller to the motor is 0; wherein the voltage output duty cycle is a duty cycle of a voltage output to the motor by the controller relative to a battery output voltage.
4. The method of claim 2, further comprising, after the voltage output to the motor is 0:
if the accelerator is started, determining a target voltage output to a motor by the controller according to the state of the accelerator;
lifting the voltage output duty cycle according to a second preset curve until the voltage output duty cycle reaches a starting compensation duty cycle; the voltage output duty ratio is the duty ratio of the voltage output by the controller to the motor relative to the output voltage of the battery;
disconnecting the electromagnetic brake;
adjusting the voltage output duty cycle to a target duty cycle; wherein the target duty cycle is a duty cycle of the target voltage with respect to the battery output voltage.
5. The method of claim 4, wherein if the current speed of the motor is within a preset range, gradually adjusting the voltage output by the controller to the motor according to a preset step value until the current speed of the motor is 0, further comprising:
and when the current speed is 0, the voltage output duty ratio output by the controller is used as the starting compensation duty ratio.
6. The method of claim 1, wherein the step of adjusting the voltage output to the motor in steps with a preset step value comprises:
determining the preset step value according to the current speed of the motor;
if the current speed of the motor is greater than 0, subtracting a preset step value from the current voltage output duty ratio; the voltage output duty ratio is the duty ratio of the voltage output by the controller to the motor relative to the output voltage of the battery;
and if the current speed of the motor is smaller than 0, adding the preset step value to the current voltage output duty ratio.
7. The method of claim 1, further comprising, after reducing the voltage output by the vehicle controller to the vehicle motor when the vehicle accelerator is released:
a current speed of the motor is calculated.
8. The method of claim 7, wherein calculating the current speed of the motor comprises:
acquiring an output voltage value of the controller and a current value of the motor;
determining a back electromotive force according to an output voltage value of the controller and a current value of the motor;
and taking the product of the back electromotive force and a preset coefficient as the current speed of the motor.
9. A vehicle control apparatus for performing the vehicle control method according to any one of claims 1 to 8;
the vehicle control device includes:
a first control module for reducing a voltage output by the vehicle controller to the vehicle motor when the vehicle accelerator is released;
the adjusting module is used for gradually adjusting the voltage output to the motor by the controller according to a preset step value until the current speed of the motor is 0 if the current speed of the motor is in a preset range or the voltage output to the motor by the controller is 0; wherein the current speed is the duty ratio of the current rotating speed of the motor relative to the full rotating speed; the full rotation speed is the rotation speed of the motor when the voltage output to the motor by the controller is equal to the output voltage of the battery;
and the second control module is used for controlling the electromagnetic brake to be closed when the step-by-step adjustment time length of the voltage output to the motor reaches a first preset time length.
10. A vehicle control system, characterized by comprising: accelerator, motor, electromagnetic brake, battery and controller; the controller includes the vehicle control apparatus of claim 9;
the accelerator is connected with the controller, and the controller is used for acquiring the state of the accelerator so as to determine whether the accelerator is released or not;
the output end of the battery is connected with the controller, the controller is connected with the motor, and the controller is used for reducing the voltage output by the controller to the motor when the accelerator is released; if the current speed of the motor is within a preset range or the voltage output to the motor by the controller is 0, the voltage output to the motor by the controller is gradually regulated according to a preset step value until the current speed of the motor is 0; wherein the current speed is a duty cycle of a current rotational speed of the motor to a ratio relative to a full rotational speed; the full rotation speed is the rotation speed of the motor when the voltage output to the motor by the controller is equal to the output voltage of the battery;
the electromagnetic brake is connected with the controller, and the controller is further used for controlling the electromagnetic brake to be closed when the time length of regulating the voltage output to the motor reaches a first preset time length.
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CN117087449A (en) * 2023-10-17 2023-11-21 凡己科技(苏州）有限公司 Industrial vehicle control method, control device and power system
CN117162808A (en) * 2023-11-02 2023-12-05 凡己科技(苏州）有限公司 Industrial vehicle hill-holding control method, control device and power system

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117087449A (en) * 2023-10-17 2023-11-21 凡己科技(苏州）有限公司 Industrial vehicle control method, control device and power system
CN117087449B (en) * 2023-10-17 2024-02-02 凡己科技(苏州）有限公司 Industrial vehicle control method, control device and power system
CN117162808A (en) * 2023-11-02 2023-12-05 凡己科技(苏州）有限公司 Industrial vehicle hill-holding control method, control device and power system
CN117162808B (en) * 2023-11-02 2024-02-02 凡己科技(苏州）有限公司 Industrial vehicle hill-holding control method, control device and power system

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