Vehicle anti-slip mode control method and system

Abstract

The invention relates to the technical field of new energy vehicles, in particular to a vehicle anti-slip mode control method and system. The method includes: acquiring a motor rotating speed direction and a gear direction; when the rotating speed direction of the motor is opposite to the gear direction, the first rotating speed of the motor and the backward sliding distance of the vehicle are obtained; when the backward sliding distance of the vehicle reaches a preset distance, the rotating speed of a second motor is obtained; and if the rotating speed of the second motor is greater than the rotating speed of the first motor, controlling the vehicle to enter an anti-slip mode. By recognizing the fluctuating rotating speed of the motor, the vehicle sliding condition is fundamentally distinguished, the vehicle condition judgment accuracy cannot be affected by the operation that a driver steps on and loosens a brake suddenly, and the problems that in the prior art, the vehicle condition is misjudged, and an anti-sliding mode is mistakenly triggered are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicles, and in particular to a vehicle anti-slope mode control method and system. Background Art

[0002] With the development of new energy vehicle technology, the anti-slope rolling technology system of new energy vehicles has gradually matured. The existing anti-slope rolling technology system determines whether the direction of the vehicle motor speed and the vehicle gear direction are opposite when the driver does not brake, and estimates the vehicle's backward sliding distance based on the motor speed, thereby determining whether the vehicle is rolling down the slope, and using the drive motor stall torque to achieve stable parking of the vehicle on the slope when the vehicle is about to roll down the slope, preventing the vehicle from rolling down the slope.

[0003] At present, new energy commercial vehicles with large loads are equipped with high-speed drive motors. When driving on a flat road, the driver's sudden braking and sudden release of the brakes can easily cause the output shaft or motor to rotate in the opposite direction of the driving gear, and the speed fluctuates between the positive and negative directions of the driving gear. At this time, because the vehicle system determines that the driver has released the brakes, and the motor has generated a reverse speed, the vehicle system misjudges that the car is sliding down a slope and enters the anti-slope mode, interfering with the normal driving of the car. Summary of the invention

[0004] The purpose of the present invention is to provide a vehicle anti-slope mode control method to solve the problem that the existing anti-slope technology system may misjudge the vehicle condition and mistakenly trigger the anti-slope mode.

[0005] In order to solve the above technical problems, the first aspect of the present invention provides a vehicle anti-slope rolling mode control method, comprising the following steps: obtaining the motor speed direction and the gear direction; when the motor speed direction and the gear direction are opposite, obtaining the first motor speed and the vehicle backward rolling distance; when the vehicle backward rolling distance reaches a preset distance, obtaining the second motor speed; if the second motor speed is greater than the first motor speed, controlling the vehicle to enter the anti-slope rolling mode.

[0006] After research, the present invention has found that the reason why the existing anti-slope technology system misjudges the vehicle situation and mis-triggers the anti-slope mode is that the existing vehicle system cannot identify the fluctuation of the speed of the vehicle motor, that is, the situation where the motor speed fluctuates between the positive and negative directions of the driving gear. In view of this, the above-mentioned vehicle anti-slope mode control method, when the motor speed direction and the vehicle gear direction are opposite, compares the first motor speed and the second motor speed of the vehicle at two moments to determine whether the motor has a fluctuating speed. If the second motor speed is greater than the first motor speed, it indicates that the vehicle motor continues to accelerate in the opposite direction of the vehicle gear, and then indicates that the motor speed does not fluctuate between the positive and negative directions of the driving gear, proving that the vehicle does have a slope-slipping situation at this moment, so the vehicle is controlled to enter the anti-slope mode. The above-mentioned vehicle anti-slope mode control method also implies that if the second motor speed is less than the first motor speed, it indicates that the vehicle motor accelerates in the opposite direction of the vehicle gear and then decelerates, and then indicates that the motor speed fluctuates between the positive and negative directions of the driving gear, proving that the vehicle does not actually have a slope-slipping situation at this moment, so the vehicle is not controlled to enter the anti-slope mode.

[0007] On this basis, the driver's sudden braking and releasing operation will cause the prior art to judge that the driver has released the brake, and the sudden braking and releasing operation will produce a fluctuating speed, which will cause the prior art to misjudge the vehicle's condition and erroneously trigger the anti-slope mode. On the contrary, the above-mentioned vehicle anti-slope mode control method will not be affected by the driver's sudden braking and releasing operation to affect the accuracy of vehicle condition judgment, thus solving the problem of the prior art misjudging the vehicle's condition and erroneously triggering the anti-slope mode.

[0008] In a possible implementation, obtaining the vehicle's backward rolling distance includes: obtaining the dynamic motor speed, speed reversal time, tire radius, gear speed ratio and axle speed ratio; based on the tire radius, the gear speed ratio and the axle speed ratio, calculating the integral of the dynamic motor speed and the speed reversal time, and then obtaining the vehicle's backward rolling distance.

[0009] It should be noted that the vehicle's backward sliding distance generally refers to the distance the vehicle slides backward toward the bottom of the slope when the vehicle slides down the slope. In this implementation, the vehicle's backward sliding distance specifically refers to the distance the vehicle system estimates the possible backward sliding distance of the vehicle based on the reverse speed of the motor and the time when the motor speed reverses. By estimating the backward sliding distance, it is possible to determine whether the vehicle will actually slide down the slope due to the reverse speed of the motor, thereby improving the accuracy of the timing of subsequently obtaining the second motor speed, improving the accuracy of judging the vehicle's sliding down the slope, and avoiding misjudgment of the vehicle's condition and mistakenly entering the anti-slope mode.

[0010] In a possible implementation, the dynamic motor speed and the integral of the speed reversal time are calculated based on the tire radius, the gear speed ratio and the axle speed ratio, and the specific calculation formula is shown in Formula 1:

[0011]

[0012] Wherein, n is the dynamic motor speed, r is the tire radius, t is the speed reversal time, i 档 is the gear ratio, i 车 is the axle speed ratio.

[0013] It should be noted that the gear ratio refers to the ratio of the input shaft speed to the output shaft speed of a certain gear of the vehicle gearbox, which determines the speed relationship between the input and output of the vehicle gearbox; the axle ratio refers to the speed ratio between the input shaft (drive shaft) and the output shaft (semi-axle) of the vehicle drive axle differential, which is used to quantify the ability of the vehicle gearbox to amplify the output torque and transmit it to the wheels. The gear ratio and the axle ratio can be multiplied to get the total speed ratio of the vehicle.

[0014] In a possible implementation, the vehicle anti-slope mode control method further includes: when the motor speed direction is the same as the gear direction, controlling the vehicle to maintain a normal mode.

[0015] In this implementation, in addition to comparing the first motor speed and the second motor speed of the vehicle at two moments to determine whether the motor has fluctuating speed, it is also determined whether the direction of the motor speed is the same as the gear direction. If, after the above step of determining that the direction of the motor speed is opposite to the gear direction, the direction of the motor speed is the same as the gear direction at a certain moment, it means that the motor speed fluctuates in two directions that are opposite to and the same as the gear direction during this time period. This implementation improves the accuracy of determining whether the motor has fluctuating speed through further conditional judgment, further avoids the possibility of misjudging the vehicle condition and erroneously triggering the anti-slope mode, thereby improving the safety of vehicle driving.

[0016] In a possible implementation, the vehicle anti-slope mode control method further includes: controlling the vehicle to maintain a normal mode in response to a preset vehicle braking signal.

[0017] In this implementation, in addition to comparing the first motor speed and the second motor speed of the vehicle at two moments to determine whether the motor has a fluctuating speed, it also detects in real time whether the driver uses the foot brake or the hand brake to generate a brake signal. When the vehicle generates a brake signal, it means that the braking system has intervened and there is no need for the anti-slope function to stop the vehicle, that is, there is no need to enter the anti-slope function. Therefore, when the user uses the foot brake or the hand brake, in response to the preset vehicle brake signal, the vehicle is controlled to maintain normal driving mode, which can avoid false triggering of the anti-slope mode. This implementation improves the accuracy of judging whether the motor has a slope slipping situation by further responding to the vehicle brake signal, further avoiding the possibility of misjudging the vehicle situation and falsely triggering the anti-slope mode, thereby improving the safety of vehicle driving.

[0018] In a possible implementation, the vehicle anti-slope mode control method further includes: controlling the vehicle to maintain a normal mode in response to a preset vehicle shift signal.

[0019] In this implementation, in addition to comparing the first motor speed and the second motor speed of the vehicle at two moments to determine whether the motor has a fluctuating speed, it also detects in real time whether the driver performs a gear shift operation to generate a gear shift signal. When the vehicle generates a gear shift signal, it means that the reversal of the vehicle's motor speed at this time is caused by the switching of positive and negative torques of the motor during gear shifting, not the occurrence of a slope rollback. Therefore, when the user performs a gear shift operation, in response to a preset vehicle shift signal, the vehicle is controlled to maintain normal driving mode, which can avoid false triggering of the anti-slope rollback mode. This implementation improves the accuracy of judging whether the motor has a slope rollback condition by further responding to the vehicle shift signal, further avoiding the possibility of misjudging the vehicle condition and falsely triggering the anti-slope rollback mode, thereby improving the safety of vehicle driving.

[0020] In a possible implementation, when the motor speed direction and the gear direction are opposite, before obtaining the first motor speed, the method further includes: obtaining the vehicle gear; and when the vehicle gear is neutral, controlling the vehicle to maintain a normal mode.

[0021] In this implementation, in addition to comparing the first motor speed and the second motor speed of the vehicle at two moments to determine whether the motor has a fluctuating speed, the vehicle gear position is also detected in real time. When the vehicle is in neutral, the vehicle is usually not in a ready state to start, and the driver has not instructed the vehicle to move forward or backward; and when the vehicle is in neutral, the power transmission system is disconnected from the motor and does not have the conditions to enter the anti-slope mode. Therefore, when the vehicle is in neutral, controlling the vehicle to maintain normal driving mode can avoid false triggering of the anti-slope mode. This implementation improves the accuracy of judging whether the motor has a slope-slipping situation through further conditional judgment, further avoids the possibility of misjudging the vehicle's condition and falsely triggering the anti-slope mode, thereby improving the safety of vehicle driving.

[0022] In a possible implementation, after controlling the vehicle to maintain a normal mode, the method further includes: clearing the backward rolling distance of the vehicle.

[0023] In this implementation, after the vehicle is controlled to maintain the normal mode, the calculated vehicle back-slip distance obtained when the motor speed direction and the vehicle gear direction are opposite is cleared, that is, after it is currently determined that the vehicle is not actually in a sliding slope situation, the previously estimated vehicle back-slip distance is cleared. This method avoids leaving behind historical data and interfering with the next judgment of the vehicle sliding slope situation, ensuring that the estimated vehicle back-slip distance data can reflect the actual state of the vehicle when the vehicle sliding slope situation is repeatedly judged in the subsequent period, thereby improving the accuracy of the control method.

[0024] A second aspect of the present invention provides a vehicle anti-slope rolling mode control system, comprising a main control module, a speed acquisition module, a gear acquisition module and a distance calculation module, wherein: the speed acquisition module is used to acquire the motor speed direction; the gear acquisition module is used to acquire the gear direction; the distance calculation module is used to acquire the vehicle backward rolling distance; the main control module is used to compare the motor speed direction and the gear direction, so that when the motor speed direction and the gear direction are opposite, a first control instruction is sent to enable the speed acquisition module to acquire the first motor speed, and when the vehicle backward rolling distance reaches a preset distance, a second control instruction is sent to enable the speed acquisition module to acquire the second motor speed; the main control module is also used to compare the first motor speed and the second motor speed, so that when the second motor speed is greater than the first motor speed, the vehicle is controlled to enter the anti-slope rolling mode.

[0025] In a possible implementation, the distance calculation module is used to obtain the vehicle's backward sliding distance, including: the speed acquisition module obtains the dynamic motor speed; the distance calculation module obtains the speed reversal time, tire radius, gear speed ratio and axle speed ratio; the distance calculation module calculates the integral of the dynamic motor speed and the speed reversal time based on the tire radius, the gear speed ratio and the axle speed ratio, and then obtains the vehicle's backward sliding distance.

[0026] In this implementation, the vehicle backward sliding distance specifically refers to the distance that the vehicle system estimates the possible backward sliding distance of the vehicle based on the reverse speed of the motor and the time when the motor speed reverses. By estimating the backward sliding distance, it is possible to determine whether the vehicle will actually slide down the slope due to the reverse speed of the motor, thereby improving the accuracy of the timing of obtaining the second motor speed later, improving the accuracy of judging the vehicle's sliding down the slope, and avoiding misjudgment of the vehicle's condition and mistakenly entering the anti-slope mode.

[0027] In a possible implementation, the dynamic motor speed and the integral of the speed reversal time are calculated based on the tire radius, the gear speed ratio and the axle speed ratio, and the specific calculation formula is shown in Formula 1:

[0028]

[0029] Wherein, n is the dynamic motor speed, r is the tire radius, t is the speed reversal time, i 档 is the gear ratio, i 车 is the axle speed ratio.

[0030] It should be noted that the gear ratio refers to the ratio of the input shaft speed to the output shaft speed of a certain gear of the vehicle gearbox, which determines the speed relationship between the input and output of the vehicle gearbox; the axle ratio refers to the speed ratio between the input shaft (drive shaft) and the output shaft (semi-axle) of the vehicle drive axle differential, which is used to quantify the ability of the vehicle gearbox to amplify the output torque and transmit it to the wheels. The gear ratio and the axle ratio can be multiplied to get the total speed ratio of the vehicle.

[0031] A vehicle anti-slope mode control method and system provided by the present invention has at least the following advantages compared with the prior art:

[0032] The above-mentioned vehicle anti-slope mode control method, when the direction of the motor speed and the direction of the vehicle gear are opposite, determines whether the motor has a fluctuating speed by comparing the first motor speed and the second motor speed of the vehicle at two moments. If the second motor speed is greater than the first motor speed, it indicates that the vehicle motor continues to accelerate in the direction opposite to the vehicle gear, and further indicates that the motor speed does not fluctuate between the positive and negative directions of the driving gear, proving that the vehicle is indeed sliding down the slope at this moment, so the vehicle is controlled to enter the anti-slope mode. The above-mentioned vehicle anti-slope mode control method also implies that if the second motor speed is less than the first motor speed, it indicates that the vehicle motor accelerates in the direction opposite to the vehicle gear and then decelerates, and further indicates that the motor speed fluctuates between the positive and negative directions of the driving gear, proving that the vehicle is not actually sliding down the slope at this moment, so the vehicle is not controlled to enter the anti-slope mode.

[0033] On this basis, the driver's sudden braking and releasing operation will cause the prior art to judge that the driver has released the brake, and the sudden braking and releasing operation will produce a fluctuating speed, which will cause the prior art to misjudge the vehicle's condition and erroneously trigger the anti-slope mode. On the contrary, the above-mentioned vehicle anti-slope mode control method will not be affected by the driver's sudden braking and releasing operation to affect the accuracy of vehicle condition judgment, thus solving the problem of the prior art misjudging the vehicle's condition and erroneously triggering the anti-slope mode. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1It is a timing diagram of the driver accidentally entering the anti-slope mode due to sudden braking and sudden release of the brakes provided by an embodiment of the present invention;

[0035] Figure 2 is a flow chart of a vehicle anti-slope mode control method provided by an embodiment of the present invention;

[0036] Figure 3 is a structural diagram of a vehicle anti-slope mode control system provided by an embodiment of the present invention;

[0037] Among them: 100, main control module; 200, speed acquisition module; 300, gear acquisition module; 400, distance calculation module. DETAILED DESCRIPTION

[0038] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0039] The following detailed descriptions are all exemplary descriptions, and are intended to provide further detailed descriptions of the present invention. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of the present application; the terms used in the specification of the application herein are only for the purpose of describing specific embodiments, and are not intended to limit the present application; the terms "including" and "having" in the specification and claims of the present application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of the present application or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

[0040] It should be understood that, although the steps in the flowchart of the accompanying drawings are displayed in sequence as indicated by the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least a part of the steps in the flowchart of the accompanying drawings may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be executed in turn or alternately with other steps or at least a part of the sub-steps or stages of other steps.

[0041] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0042] Before describing the present application in detail in conjunction with the embodiments, the application scenarios involved in the present application are first described.

[0043] With the promotion of new energy vehicles, the anti-slip technology of new energy vehicles is becoming more and more mature. The current entry conditions and methods of the anti-slip strategy for new energy vehicles are as follows:

[0044] S1. Determine whether the vehicle has a foot brake signal or a hand brake signal.

[0045] S2: When the vehicle has no foot brake signal and hand brake signal, determine whether the motor speed is opposite to the vehicle speed.

[0046] S3: When the motor speed and the vehicle gear position are in opposite directions, the slope sliding distance is estimated, and when the slope sliding distance reaches the warning value, the vehicle is controlled to enter the anti-slope sliding mode.

[0047] At present, new energy commercial vehicles with large loads are equipped with high-speed drive motors. When driving on a flat road, the driver's sudden braking and quick release of the brakes can easily cause the output shaft or motor to rotate in the opposite direction of the driving gear, and the speed fluctuates between the positive and negative directions of the driving gear. At this time, because the driver has released the brakes, the vehicle has no brake signal, and the motor has generated a reverse speed, causing the vehicle system to misjudge that the vehicle is sliding down a slope and enter the anti-slope mode, interfering with the normal driving of the vehicle.

[0048] See also Figure 1 , Figure 1This is a timing diagram of the driver suddenly pressing and releasing the brake, causing the vehicle to mistakenly enter the anti-slope mode. A new energy commercial vehicle with a large load is equipped with a high-speed drive motor. When driving on a flat road, the driver suddenly presses the brake at time a, that is, presses the brake pedal, and the vehicle generates a brake pedal signal; the brake pedal depth begins to rise; the motor target torque, motor actual torque, motor speed and vehicle speed begin to decrease. At time b, the motor target torque and motor actual torque drop to 0. At time c, the motor speed drops to 0 in the positive direction and begins to accelerate in the negative direction. At time d, the motor speed is opposite to the vehicle gear position, and the motor reverse speed reaches the maximum. The driver suddenly releases the brake at time e, that is, the brake pedal is not pressed, the vehicle brake pedal signal disappears, the brake pedal depth decreases, and the motor speed is still opposite to the vehicle gear position. At this time, the vehicle system enters step S3 and starts to estimate the slope distance. At time f, the system estimates that the slope distance reaches the warning value, controls the vehicle to enter the anti-slope mode, and the anti-slope flag generates a standing wave. At this time, the vehicle system misjudged that the car was sliding down a slope and entered the anti-slope mode, interfering with the normal driving of the car.

[0049] In order to solve the above technical problems, see Figure 2 The embodiment of the present invention provides a vehicle anti-slope mode control method, comprising the following steps:

[0050] S101, obtaining the motor speed direction and gear direction.

[0051] S102: When the motor speed direction is opposite to the gear direction, obtain the first motor speed and the vehicle backward rolling distance.

[0052] S103: When the backward rolling distance of the vehicle reaches a preset distance, obtaining a second motor speed.

[0053] S104: If the speed of the second motor is greater than the speed of the first motor, control the vehicle to enter an anti-slope mode.

[0054] In a possible embodiment, obtaining the vehicle's backward rolling distance includes: obtaining the dynamic motor speed, speed reversal time, tire radius, gear speed ratio and axle speed ratio; based on the tire radius, the gear speed ratio and the axle speed ratio, calculating the integral of the dynamic motor speed and the speed reversal time, and then obtaining the vehicle's backward rolling distance.

[0055] It should be noted that the vehicle backward sliding distance generally refers to the distance that the vehicle slides backward toward the bottom of the slope when the vehicle slides down the slope. In this embodiment, the vehicle backward sliding distance specifically refers to the distance that the vehicle system estimates the possible backward sliding of the vehicle based on the reverse speed of the motor and the time when the motor speed reverses. By estimating the backward sliding distance, it is possible to determine whether the vehicle will actually slide down the slope due to the reverse speed of the motor, thereby improving the accuracy of the timing of subsequently obtaining the second motor speed, improving the accuracy of judging the vehicle's sliding down the slope, and avoiding misjudgment of the vehicle's condition and mistakenly entering the anti-slope mode.

[0056] In a possible embodiment, the dynamic motor speed and the integral of the speed reversal time are calculated based on the tire radius, the gear speed ratio and the axle speed ratio, and the specific calculation formula is shown in Formula 1:

[0057]

[0058] Wherein, n is the dynamic motor speed, r is the tire radius, t is the speed reversal time, i 档 is the gear ratio, i 车 is the axle speed ratio.

[0059] It should be noted that the gear ratio refers to the ratio of the input shaft speed to the output shaft speed of a certain gear of the vehicle gearbox, which determines the speed relationship between the input and output of the vehicle gearbox; the axle ratio refers to the speed ratio between the input shaft (drive shaft) and the output shaft (semi-axle) of the vehicle drive axle differential, which is used to quantify the ability of the vehicle gearbox to amplify the output torque and transmit it to the wheels. The gear ratio and the axle ratio can be multiplied to get the total speed ratio of the vehicle.

[0060] In a possible embodiment, the vehicle anti-slope mode control method further includes: when the motor speed direction is the same as the gear direction, controlling the vehicle to maintain a normal mode.

[0061] In this embodiment, in addition to comparing the first motor speed and the second motor speed of the vehicle at two moments to determine whether the motor has fluctuating speed, it is also determined whether the direction of the motor speed is the same as the gear direction. If, after the above step of determining that the direction of the motor speed is opposite to the gear direction, the direction of the motor speed is the same as the gear direction at a certain moment, it means that the motor speed fluctuates in two directions that are opposite to and the same as the gear direction during this time period. This embodiment improves the accuracy of determining whether the motor has fluctuating speed through further conditional judgment, further avoids the possibility of misjudging the vehicle condition and erroneously triggering the anti-slope mode, thereby improving the safety of vehicle driving.

[0062] In a possible embodiment, the vehicle anti-slope mode control method further includes: controlling the vehicle to maintain a normal mode in response to a preset vehicle braking signal.

[0063] In this embodiment, in addition to comparing the first motor speed and the second motor speed of the vehicle at two moments to determine whether the motor has a fluctuating speed, it also detects in real time whether the driver uses the foot brake or the hand brake to generate a brake signal. When the vehicle generates a brake signal, it means that the reversal of the motor speed of the vehicle at this time is caused by the driver using the foot brake or the hand brake when driving at high speed, not the occurrence of a rollback. Therefore, when the user uses the foot brake or the hand brake, in response to the preset vehicle brake signal, the vehicle is controlled to maintain normal driving mode, which can avoid false triggering of the anti-rollback mode. This embodiment improves the accuracy of judging whether the motor has a rollback situation by further responding to the vehicle brake signal, further avoids the possibility of misjudging the vehicle situation and falsely triggering the anti-rollback mode, thereby improving the safety of vehicle driving.

[0064] In a possible embodiment, the vehicle anti-slope mode control method further includes: controlling the vehicle to maintain a normal mode in response to a preset vehicle shift signal.

[0065] In this embodiment, in addition to comparing the first motor speed and the second motor speed of the vehicle at two moments to determine whether the motor has a fluctuating speed, it also detects in real time whether the driver performs a gear shift operation to generate a gear shift signal. When the vehicle generates a gear shift signal, it means that the reversal of the motor speed of the vehicle at this time is caused by the switching of positive and negative torques of the motor during gear shifting, not the occurrence of a slope rollback. Therefore, when the user performs a gear shift operation, in response to a preset vehicle shift signal, the vehicle is controlled to maintain normal driving mode, which can avoid false triggering of the anti-slope rollback mode. This embodiment improves the accuracy of judging whether the motor has a slope rollback condition by further responding to the vehicle shift signal, further avoids the possibility of misjudging the vehicle condition and falsely triggering the anti-slope rollback mode, thereby improving the safety of vehicle driving.

[0066] In a possible embodiment, when the motor speed direction and the gear direction are opposite, before obtaining the first motor speed, the method further includes: obtaining the vehicle gear; and when the vehicle gear is neutral, controlling the vehicle to maintain a normal mode.

[0067] In this embodiment, in addition to comparing the first motor speed and the second motor speed of the vehicle at two moments to determine whether the motor has a fluctuating speed, the vehicle gear position is also detected in real time. When the vehicle is in neutral, the vehicle is usually not in a ready state to start, and the driver has not instructed the vehicle to move forward or backward; and when the vehicle is in neutral, the power system is disconnected from the motor, which means that there is no rollback at this time. Therefore, when the vehicle is in neutral, controlling the vehicle to maintain normal driving mode can avoid false triggering of the anti-rollback mode. This embodiment improves the accuracy of judging whether the motor has a rollback through further conditional judgments, further avoids the possibility of misjudging the vehicle's condition and falsely triggering the anti-rollback mode, thereby improving the safety of vehicle driving.

[0068] In a possible embodiment, after controlling the vehicle to maintain a normal mode, the method further includes: clearing the vehicle's backward rolling distance to zero.

[0069] In this embodiment, after the vehicle is controlled to maintain the normal mode, the vehicle backward sliding distance calculated when the motor speed direction and the vehicle gear direction are opposite is cleared, that is, after it is currently determined that the vehicle is not actually in a sliding slope situation, the previously estimated vehicle backward sliding distance is cleared. This method avoids leaving behind historical data and interfering with the next judgment of the vehicle sliding slope situation, ensuring that the estimated vehicle backward sliding distance data can reflect the actual state of the vehicle when the vehicle sliding slope situation is repeatedly judged in the subsequent repeated judgment, thereby improving the accuracy of the control method.

[0070] See also Figure 3 An embodiment of the present invention provides a vehicle anti-slope sliding mode control system, comprising a main control module 100, a speed acquisition module 200, a gear acquisition module 300 and a distance calculation module 400, wherein: the speed acquisition module 200 is used to acquire the motor speed direction; the gear acquisition module 300 is used to acquire the gear direction; the distance calculation module 400 is used to acquire the vehicle backward sliding distance; the main control module 100 is used to compare the motor speed direction and the gear direction, so that when the motor speed direction and the gear direction are opposite, a first control instruction is sent to enable the speed acquisition module 200 to acquire the first motor speed, and when the vehicle backward sliding distance reaches a preset distance, a second control instruction is sent to enable the speed acquisition module 200 to acquire the second motor speed; the main control module 100 is also used to compare the first motor speed and the second motor speed, so that when the second motor speed is greater than the first motor speed, the vehicle is controlled to enter the anti-slope sliding mode.

[0071] In a possible embodiment, the distance calculation module 400 is used to obtain the vehicle's backward slip distance, including: the speed acquisition module 200 obtains the dynamic motor speed; the distance calculation module 400 obtains the speed reversal time, tire radius, gear speed ratio and axle speed ratio; the distance calculation module 400 calculates the integral of the dynamic motor speed and the speed reversal time based on the tire radius, the gear speed ratio and the axle speed ratio, and then obtains the vehicle's backward slip distance.

[0072] In this embodiment, the vehicle backward sliding distance specifically refers to the possible backward sliding distance estimated by the vehicle system according to the reverse speed of the motor and the time when the motor speed reverses. By estimating the backward sliding distance, it is possible to determine whether the vehicle will actually slide down the slope due to the reverse speed of the motor, thereby improving the accuracy of the timing of obtaining the second motor speed later, improving the accuracy of determining the vehicle's sliding down the slope, and avoiding misjudgment of the vehicle's condition and mistakenly entering the anti-slope mode.

[0073] In a possible embodiment, the dynamic motor speed and the integral of the speed reversal time are calculated based on the tire radius, the gear speed ratio and the axle speed ratio, and the specific calculation formula is shown in Formula 1:

[0074]

[0075] Wherein, n is the dynamic motor speed, r is the tire radius, t is the speed reversal time, i 档 is the gear ratio, i 车 is the axle speed ratio.

[0076] It should be noted that the gear ratio refers to the ratio of the input shaft speed to the output shaft speed of a certain gear of the vehicle gearbox, which determines the speed relationship between the input and output of the vehicle gearbox; the axle ratio refers to the speed ratio between the input shaft (drive shaft) and the output shaft (semi-axle) of the vehicle drive axle differential, which is used to quantify the ability of the vehicle gearbox to amplify the output torque and transmit it to the wheels. The gear ratio and the axle ratio can be multiplied to get the total speed ratio of the vehicle.

[0077] In a possible embodiment, the embodiment of the present invention provides another vehicle anti-slope mode control method, comprising the following steps:

[0078] S210, determine whether the vehicle gear is in neutral; if not, execute S220.

[0079] S220, determining whether the vehicle handbrake signal, the vehicle footbrake signal and the vehicle shift signal are all invalid; if so, executing S230; if not, executing S210.

[0080] S230. When the motor speed direction and the gear direction are opposite, obtain the first motor speed and the vehicle backward sliding distance; when the vehicle backward sliding distance reaches a preset distance, obtain the second motor speed; if the second motor speed is greater than the first motor speed, control the vehicle to enter the anti-slope sliding mode.

[0081] S240: Clearing the vehicle's backward rolling distance to zero.

[0082] In a possible embodiment, while implementing step S230, it also includes step S231: when the motor speed direction and the gear direction are the same, control the vehicle to maintain normal mode and execute step S240; in response to a vehicle handbrake signal or a vehicle foot brake signal, control the vehicle to maintain normal mode and execute step S240; in response to a vehicle shift signal, control the vehicle to maintain normal mode and execute step S240.

[0083] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but are not limited to this.

[0084] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope recorded in this specification.

[0085] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the present application. It should be noted that, for a person of ordinary skill in the art, several improvements and substitutions may be made without departing from the concept of the present application, and these improvements and substitutions shall also be regarded as the protection scope of the present invention. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A vehicle anti-slope mode control method, characterized in that: include: Get the motor speed direction and gear direction; When the motor speed direction is opposite to the gear direction, obtaining the first motor speed and the vehicle backward sliding distance; When the backward sliding distance of the vehicle reaches a preset distance, obtaining the second motor speed; If the speed of the second motor is greater than the speed of the first motor, the vehicle is controlled to enter an anti-slope mode.

2. A vehicle anti-slope mode control method according to claim 1, characterized in that: The obtaining of the vehicle backward sliding distance comprises: Get dynamic motor speed, speed reversal time, tire radius, gear ratio and axle ratio; Based on the tire radius, the gear speed ratio and the axle speed ratio, the integral of the dynamic motor speed and the speed reversal time is calculated to obtain the vehicle backward slip distance.

3. A vehicle anti-slope mode control method according to claim 2, characterized in that: The integral of the dynamic motor speed and the speed reversal time is calculated based on the tire radius, the gear speed ratio and the axle speed ratio, and the specific calculation formula is: Wherein, n is the dynamic motor speed, r is the tire radius, t is the speed reversal time, i 档 is the gear ratio, i 车 is the axle speed ratio.

4. The vehicle anti-slope mode control method according to claim 1, characterized in that: Also includes: When the motor speed direction is the same as the gear direction, the vehicle is controlled to maintain a normal mode.

5. The vehicle anti-slope mode control method according to claim 1, characterized in that: Also includes: In response to a preset vehicle brake signal, the vehicle is controlled to maintain a normal mode.

6. The vehicle anti-slope mode control method according to claim 1, characterized in that: Also includes: In response to a preset vehicle shift signal, the vehicle is controlled to maintain a normal mode.

7. A vehicle anti-slope mode control method according to claim 1, characterized in that: When the motor speed direction and the gear direction are opposite, before obtaining the first motor speed, the method further includes: Get the vehicle gear position; When the vehicle gear is in neutral, the vehicle is controlled to maintain a normal mode.

8. A vehicle anti-slope mode control system, characterized in that: It includes a main control module, a speed acquisition module, a gear acquisition module and a distance calculation module, among which: The speed acquisition module is used to acquire the speed direction of the motor; The gear position acquisition module is used to acquire the gear position direction; The distance calculation module is used to obtain the vehicle's backward sliding distance; The main control module is used to compare the motor speed direction and the gear direction, so as to send a first control instruction to enable the speed acquisition module to acquire the first motor speed when the motor speed direction and the gear direction are opposite, and send a second control instruction to enable the speed acquisition module to acquire the second motor speed when the rearward rolling distance of the vehicle reaches a preset distance; The main control module is further used to compare the first motor speed and the second motor speed, so as to control the vehicle to enter an anti-slope mode when the second motor speed is greater than the first motor speed.

9. The vehicle anti-slope mode control system according to claim 8, characterized in that: The distance calculation module is used to obtain the vehicle's backward sliding distance, including: The speed acquisition module acquires the dynamic motor speed; The distance calculation module obtains the speed reversal time, tire radius, gear ratio and axle ratio; The distance calculation module calculates the integral of the dynamic motor speed and the speed reversal time based on the tire radius, the gear speed ratio and the axle speed ratio, and then obtains the vehicle backward sliding distance.

10. The vehicle anti-slope mode control system according to claim 9, characterized in that: The integral of the dynamic motor speed and the speed reversal time is calculated based on the tire radius, the gear speed ratio and the axle speed ratio, and the specific calculation formula is: Wherein, n is the dynamic motor speed, r is the tire radius, t is the speed reversal time, i 档 is the gear ratio, i 车 is the axle speed ratio.

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