A method and device for automatically exiting an off-road mode of a vehicle

Abstract

The present application belongs to the field of vehicle control technology, and particularly relates to a kind of automobile off-road mode automatic exit control method, the control method includes road surface identification method and mode exit method;When vehicle manually enters off-road mode, vehicle obtains the signal of rainfall sensor, judges whether current is rain and snow weather, if it is rain and snow weather, control vehicle to enter off-road mode;Vehicle obtains position information and weather information of current position through Internet of Vehicles, judges the road condition information of current position, determines whether there is road wet or icing warning information, if there is road wet or icing warning information, control vehicle to enter off-road mode;Vehicle determines the road grade and road material of current driving road surface according to position information.It overcomes the shortcomings of prior art, formulates the automatic exit mechanism of off-road mode through the collection of road surface condition and driving condition, can minimize fuel consumption, protect transmission system parts and reduce failure rate.

Description

Technical Field

[0001] This invention belongs to the field of vehicle control technology, specifically relating to a method and device for automatically exiting off-road mode in automobiles. Background Technology

[0002] The vehicle owner's manual will remind users that off-road mode should not be used for extended periods. With current technology, users can manually switch to off-road mode on good roads and use it for extended periods without the vehicle providing any warnings or intervention.

[0003] In off-road mode, the four-wheel drive system connects the front and rear axles almost rigidly. When driving on good roads, especially when turning, the front and rear axles interfere with each other due to the different distances they travel, resulting in a larger torque in the transmission system. If used for a long time, this can lead to increased fuel consumption, reduced lifespan of transmission system parts, and even damage or failure of transmission system parts in extreme cases. Summary of the Invention

[0004] The purpose of this invention is to provide a method and device for automatically exiting off-road mode in automobiles, which overcomes the shortcomings of the prior art. By collecting data on road conditions and driving conditions, an automatic exit mechanism for off-road mode is established, which can minimize fuel consumption, protect transmission system components, and reduce the failure rate.

[0005] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0006] A method for automatically exiting off-road mode of a vehicle, the method comprising a road surface recognition method and a mode exit method;

[0007] The road surface recognition method specifically includes the following steps:

[0008] Step 1: When the vehicle is manually put into off-road mode, the vehicle obtains a signal from the rain sensor to determine whether it is raining or snowing. If it is raining or snowing, the vehicle is put into off-road mode; otherwise, proceed to step 2.

[0009] Step 2: The vehicle obtains location information and current weather information through the vehicle network, judges the current road conditions, and determines whether there is a warning of slippery or icy roads. If there is a warning of slippery or icy roads, the vehicle is controlled to enter off-road mode; otherwise, proceed to step 2.

[0010] Step 3: The vehicle determines the road grade and road material of the current road surface based on the location information. If the road surface is poor, the vehicle is controlled to enter off-road mode; otherwise, proceed to step 4.

[0011] Step 4: The vehicle starts its onboard camera and uses image processing technology to process and analyze the image data to obtain road surface characteristic parameters and determine whether the road surface is good.

[0012] The mode exit method includes the following steps:

[0013] When the vehicle is in off-road mode and driving on a good road surface, the steering wheel angle signal is acquired to determine the driver's level of aggressive driving; specifically including:

[0014] (1) When the steering wheel angle is less than 90°, the driving behavior is judged to be relatively gentle, and the driver is reminded. If the off-road mode is maintained for a long time, the off-road mode will automatically exit.

[0015] (2) When the steering wheel angle is within the range of 90° to 360°, the driving behavior is judged to be relatively intense. The off-road mode will automatically exit when there are multiple intense turns in a row.

[0016] (3) When the steering wheel angle is greater than 360°, the driving behavior is judged as aggressive driving. If there are multiple aggressive turns in a row, the off-road mode will be automatically exited.

[0017] Furthermore, the road grades mentioned in step three include national highways, provincial highways, county roads, and township roads, and the road materials include asphalt pavement, cement pavement, gravel pavement, and dirt pavement.

[0018] Furthermore, step 4, which involves processing and analyzing image data using image processing techniques, includes the following steps:

[0019] Step 4.1: Image Grayscale Processing

[0020] R′=G′=B′=ω1R+ω2R+ω3R

[0021] ω1+ω2+ω3=1

[0022] A color can be composed of three primary colors: R, G, and B. A grayscale image can be obtained by weighted averaging of a color image, where ω1, ω2, and ω3 are the weights of R, G, and B, respectively. Since the human eye is sensitive to the three colors differently, based on theoretical derivation and related experimental verification, the grayscale image obtained when ω1 = 0.3, ω2 = 0.59, and ω3 = 0.11 is the most reasonable.

[0023] Step 4.2, Defining the Region of Interest

[0024] Based on the images captured by the vehicle-mounted camera, a coordinate system is established with the lower left corner as the origin. The region of interest is defined as the area ABCD enclosed by lines l1, l2, l3 and the X-axis of the coordinate system; where:

[0025] l1=k1x1+b1

[0026] l2=k2x2+b2

[0027] l3=y0

[0028] Among them, k1, k2, b1, b2, and y0 are customized according to the different angles, ranges, and pixel sizes of the images captured by the device;

[0029] Step 4.3, Calculation of pavement characteristic parameters

[0030] Calculate the average gray value and variance of the road surface feature values ​​in the region of interest.

[0031] Let z i Let i = 1, 2, 3, ..., L-1, representing all possible gray values ​​within a region of interest image with a total of M pixels, where z is a given gray value. k The probability of occurrence p(z) k It can be estimated as follows:

[0032]

[0033] Where n k It is the grayscale value z k The number of times it appears within the range of interest, where M is the total number of pixels.

[0034]

[0035] The average grayscale value is:

[0036]

[0037] The variance of the grayscale values ​​is:

[0038]

[0039] Step 4.4: Compare with the standard database

[0040] The standard database stores standard data for good road surfaces under different environmental conditions. The calculation results are compared with the standard data. If the calculation results do not exceed ±5% of the standard value, the vehicle is determined to be driving on a good adhesion road surface.

[0041] Furthermore, when the steering wheel is turned within a range of less than 90°, if the driving time exceeds 10 minutes, the vehicle will issue an alarm to prompt the driver to exit the off-road mode. If the driving time exceeds 20 minutes, the vehicle will automatically exit the off-road mode and prompt the driver.

[0042] Furthermore, when the steering wheel angle is within the range of 90° to 360°, and the driving time exceeds 5 minutes or the number of turns exceeds 20, the vehicle will issue an alarm to prompt the driver to exit the off-road mode. When the driving time exceeds 10 minutes or the number of turns exceeds 40, the vehicle will automatically exit the off-road mode and issue a prompt to the driver.

[0043] Furthermore, when the steering wheel angle is greater than 360° and the driving time exceeds 3 minutes or the number of turns exceeds 10, the vehicle will issue an alarm to prompt the driver to exit the off-road mode. When the driving time exceeds 5 minutes or the number of turns exceeds 20, the vehicle will automatically exit the off-road mode and issue a prompt to the driver.

[0044] Furthermore, the alarm includes a text prompt stating "Good road surface indicated, off-road mode should not be used for extended periods," along with a "beep beep" sound. The prompt also includes a text prompt stating "Off-road mode has been exited," along with a "beep beep" sound.

[0045] This invention also applies for protection of an automatic off-road mode exit control device for automobiles, including a steering control unit, a rain sensor, a vehicle networking unit, an on-board camera, an image processing unit, a main control unit, a CAN bus, an off-road mode control unit, and a four-wheel drive system assembly;

[0046] The steering control unit is used to acquire the steering angle signal of the vehicle's steering wheel and transmit the signal to the main control unit;

[0047] The rain sensor is used to obtain information on whether it is currently raining or snowing, and transmits the signal to the main control unit;

[0048] The vehicle networking unit is used to connect to the network to obtain the vehicle's location information and the current weather information, and transmit the signal to the main control unit;

[0049] The vehicle-mounted camera is used to capture images of the road surface on which the vehicle is traveling and to transmit the images to the image processing unit;

[0050] The image processing unit is used to process the images captured by the vehicle-mounted camera to obtain the feature parameters of the road surface.

[0051] The main control unit is used to receive signals and send commands to the off-road mode control unit via the CAN bus, thereby controlling the mode of the four-wheel drive system assembly.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] The present invention discloses a method and device for automatically exiting off-road mode, which collects steering wheel angle signals, rainfall signals, vehicle data, environmental data, vehicle camera data, and vehicle Internet information. It uses a "good road surface recognition strategy" to determine whether the road surface is good. If the road surface is not good, the user is allowed to use off-road mode. If the road surface is good, the "off-road mode automatic exit strategy" executes relevant prompts and automatic exit operations. This can minimize fuel consumption, protect transmission system components, and reduce the failure rate. Attached Figure Description

[0054] Figure 1 This is a flowchart illustrating the road surface recognition method in an automatic exit control method for off-road mode of a vehicle.

[0055] Figure 2 This is a flowchart illustrating the mode exit method in an automatic exit control method for off-road driving.

[0056] Figure 3 This is a block diagram illustrating the structural principle of an automatic exit control device for off-road mode in automobiles. Detailed Implementation

[0057] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0058] Example 1

[0059] like Figures 1-2 As shown, this embodiment discloses an automatic exit control method for off-road mode of a vehicle, which includes a road surface recognition method and a mode exit method;

[0060] The road surface recognition method specifically includes the following steps:

[0061] Step 1: When the vehicle is manually put into off-road mode, the vehicle obtains a signal from the rain sensor to determine whether it is raining or snowing. If it is raining or snowing, the vehicle is put into off-road mode; otherwise, proceed to step 2.

[0062] Step 2: The vehicle obtains location information and current weather information through the vehicle network, judges the current road conditions, and determines whether there is a warning of slippery or icy roads. If there is a warning of slippery or icy roads, the vehicle is controlled to enter off-road mode; otherwise, proceed to step 2.

[0063] Step 3: The vehicle determines the road grade and road material of the current road surface based on the location information. If the road surface is poor, the vehicle is controlled to enter off-road mode; otherwise, proceed to step 4.

[0064] Step 4: The vehicle starts its onboard camera and uses image processing technology to process and analyze the image data to obtain road surface characteristic parameters and determine whether the road surface is good.

[0065] The mode exit method includes the following steps:

[0066] When the vehicle is in off-road mode and driving on a good road surface, the steering wheel angle signal is acquired to determine the driver's level of aggressive driving; specifically including:

[0067] (1) When the steering wheel angle is less than 90°, the driving behavior is judged to be relatively gentle, and the driver is reminded. If the off-road mode is maintained for a long time, the off-road mode will automatically exit.

[0068] (2) When the steering wheel angle is within the range of 90° to 360°, the driving behavior is judged to be relatively intense. The off-road mode will automatically exit when there are multiple intense turns in a row.

[0069] (3) When the steering wheel angle is greater than 360°, the driving behavior is judged as aggressive driving. If there are multiple aggressive turns in a row, the off-road mode will be automatically exited.

[0070] In step three, the road classification includes national highways, provincial highways, county roads, and township roads, and the road materials include asphalt pavement, cement pavement, gravel pavement, and dirt pavement.

[0071] Step 4 involves processing and analyzing the image data using image processing techniques, including the following steps:

[0072] Step 4.1: Image Grayscale Processing

[0073] R′=G′=B′=ω1R+ω2R+ω3R

[0074] ω1+ω2+ω3=1

[0075] A color can be composed of three primary colors: R, G, and B. A grayscale image can be obtained by weighted averaging of a color image, where ω1, ω2, and ω3 are the weights of R, G, and B, respectively. Since the human eye is sensitive to the three colors differently, based on theoretical derivation and related experimental verification, the grayscale image obtained when ω1 = 0.3, ω2 = 0.59, and ω3 = 0.11 is the most reasonable.

[0076] Step 4.2, Defining the Region of Interest

[0077] Based on the images captured by the vehicle-mounted camera, a coordinate system is established with the lower left corner as the origin. The region of interest is defined as the area ABCD enclosed by lines l1, l2, l3 and the X-axis of the coordinate system; where:

[0078] l1=k1x1+b1

[0079] l2=k2x2+b2

[0080] l3=y0

[0081] Among them, k1, k2, b1, b2, and y0 are customized according to the different angles, ranges, and pixel sizes of the images captured by the device;

[0082] Step 4.3, Calculation of pavement characteristic parameters

[0083] Calculate the average gray value and variance of the road surface feature values ​​in the region of interest.

[0084] Let z i Let i = 1, 2, 3, ..., L-1, representing all possible gray values ​​within a region of interest image with a total of M pixels, where z is a given gray value. k The probability of occurrence p(z) k It can be estimated as follows:

[0085]

[0086] Where n k It is the grayscale value z k The number of times it appears within the range of interest, where M is the total number of pixels.

[0087]

[0088] The average grayscale value is:

[0089]

[0090] The variance of the grayscale values ​​is:

[0091]

[0092] Step 4.4: Compare with the standard database

[0093] The standard database stores standard data for good road surfaces under different environmental conditions. The calculation results are compared with the standard data. If the calculation results do not exceed ±5% of the standard value, the vehicle is determined to be driving on a good adhesion road surface.

[0094] When the steering wheel is turned within a range of less than 90°, and the driving time exceeds 10 minutes, the vehicle will issue a warning to the driver to exit the off-road mode. If the driving time exceeds 20 minutes, the vehicle will automatically exit the off-road mode and issue a warning to the driver.

[0095] When the steering wheel angle is turned within the range of 90° to 360°, and the driving time exceeds 5 minutes or the number of turns exceeds 20, the vehicle will issue a warning to prompt the driver to exit the off-road mode. If the driving time exceeds 10 minutes or the number of turns exceeds 40, the vehicle will automatically exit the off-road mode and prompt the driver.

[0096] When the steering wheel is turned more than 360°, the driving time exceeds 3 minutes or the number of turns exceeds 10, the vehicle will issue a warning to the driver to exit off-road mode. If the driving time exceeds 5 minutes or the number of turns exceeds 20, the vehicle will automatically exit off-road mode and issue a prompt to the driver.

[0097] The aforementioned time points are based on the selection of the test vehicle in this application. Those skilled in the art can select the time points based on the specific vehicle model and the characteristics of the four-wheel drive system.

[0098] The alarm includes displaying the text "Good road surface indicated, off-road mode should not be used for extended periods" on the instrument panel or head-up display, along with a "beep beep" sound. The warning also includes displaying the text "Off-road mode has been deactivated" on the instrument panel or head-up display, along with a "beep beep" sound.

[0099] Example 2

[0100] Based on Embodiment 1, this embodiment discloses an automatic off-road mode exit control device for automobiles, including a steering control unit, a rain sensor, a vehicle networking unit, an on-board camera, an image processing unit, a main control unit, a CAN bus, an off-road mode control unit, and a four-wheel drive system assembly.

[0101] The steering control unit is used to acquire the steering angle signal of the vehicle's steering wheel and transmit the signal to the main control unit;

[0102] Rain sensors are used to obtain information on whether it is currently raining or snowing, and transmit the signal to the main control unit;

[0103] The vehicle networking unit is used to connect to the network to obtain the vehicle's location information and the current weather information, and transmit the signals to the main control unit;

[0104] The vehicle-mounted camera is used to capture images of the road surface where the vehicle is traveling and transmits the images to the image processing unit;

[0105] The image processing unit is used to process the images captured by the vehicle-mounted camera to obtain the feature parameters of the road surface.

[0106] The main control unit is used to receive signals and send commands to the off-road mode control unit via the CAN bus, thereby controlling the mode of the four-wheel drive system assembly.

[0107] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A method for automatically exiting an off-road mode of a vehicle, the method comprising: The control method comprises a road surface identification method and a mode exit method; ​ The road surface identification method specifically comprises the following steps: Step 1: When the vehicle manually enters the off-road mode, the vehicle acquires the signal of the rain sensor, judges whether it is currently raining and snowing, and if so, controls the vehicle to enter the off-road mode, otherwise, enters step 2; Step 2: The vehicle acquires the location information and weather information of the current location through the Internet of Vehicles, judges the road condition information of the current location, and determines whether there is a road wet or icy warning information, if so, controls the vehicle to enter the off-road mode, otherwise, enters step 3; Step 3: The vehicle judges the road grade and road material of the current driving road surface according to the location information, if the road surface is a poor road surface, controls the vehicle to enter the off-road mode, otherwise, enters step 4; Step 4: The vehicle starts the vehicle-mounted camera, processes and analyzes the image data through image processing technology, obtains the driving road surface feature parameters, and judges whether it is a good road surface; The mode exit method comprises the following steps: When the vehicle is driving on a good road surface in the off-road mode, the steering wheel angle signal of the vehicle is acquired to determine the degree of intense driving of the driver; specifically comprising: (1) When the steering wheel angle is less than 90°, it is determined that the driving behavior is relatively gentle, the driver is reminded, and the off-road mode is automatically exited when the off-road mode is maintained for a long time; (2) When the steering wheel angle is in the range of 90° to 360°, it is determined that the driving behavior is relatively intense, and the off-road mode is automatically exited when the steering is continuously and intensely turned for multiple times; (3) When the steering wheel angle is greater than 360°, it is determined that the driving behavior is intense driving, and the off-road mode is automatically exited when the steering is continuously and intensely turned for multiple times.

2. The method of claim 1, wherein: The road grade in step three comprises national roads, provincial roads, county roads and township roads, and the road material comprises asphalt road surface, cement road surface, gravel road surface and soil road surface.

3. The method of claim 1, wherein: In step 4, the image data is processed and analyzed through image processing technology, comprising the following steps: Step 4.1, image gray processing R'=G'=B'=ω1R+ω2R+ω3R ω1+ω2+ω3=1 One color can be composed of R, G and B three primary colors, and a gray image can be obtained by weighted average of a color image, wherein ω1, ω2 and ω3 are weight values of R, G and B respectively, since the sensitivity of human eyes to the three colors is different, according to theoretical derivation and related experimental verification, ω1=0.3, ω2=0.59 and ω3=0.11, and the gray image obtained is the most reasonable; Step 4.2, interest region definition Based on the image collected by the vehicle-mounted camera, a coordinate system is established with the lower left corner as the coordinate origin, and the interest region is defined as the region ABCD surrounded by lines l1, l2, l3 and the X-axis of the coordinate system; wherein: l1=k1x1+b1 l2=k2x2+b2 l3＝y0 Wherein, k1, k2, b1, b2 and y0 are self-defined due to different device image collection angles, ranges and pixel sizes; Step 4.3, road surface feature parameter calculation The road surface feature value average gray value and variance of the interest region are calculated, Let z i , i = 1, 2, 3,..., L-1, represent all possible gray values within the region of interest image with total pixels M, the probability p(z k ) of a given gray value z k appearing can be estimated as: where n k is the gray value z k the number of times that the range of interest occurs, M is the total number of pixels, The average gray value is: The variance of the gray value is: Step 4.4, comparing with the standard database The standard database stores standard data of good road surface under different environmental data, and the calculation result is compared with the standard data. If the calculation result is not more than ±5% of the standard value, it is determined that the vehicle is driving on a good adhesion road surface.

4. The method of claim 1, wherein: When the steering wheel angle is less than 90°, the vehicle sends a warning to the driver to exit the off-road mode when the driving time exceeds 10 minutes, and automatically exits the off-road mode and sends a prompt to the driver when the driving time exceeds 20 minutes.

5. The method of claim 1, wherein: When the steering wheel angle is in the range of 90° to 360°, the vehicle sends a warning to the driver to exit the off-road mode when the driving time exceeds 5 minutes or the steering frequency exceeds 20 times, and automatically exits the off-road mode and sends a prompt to the driver when the driving time exceeds 10 minutes or the steering frequency exceeds 40 times.

6. The method of claim 1, wherein: When the steering wheel angle is greater than 360°, the vehicle sends a warning to the driver to exit the off-road mode when the driving time exceeds 3 minutes or the steering frequency exceeds 10 times, and automatically exits the off-road mode and sends a prompt to the driver when the driving time exceeds 5 minutes or the steering frequency exceeds 20 times.

7. A method of automatic control of the exit from an off-road mode of a motor vehicle according to any one of claims 4 to 6, characterized in that: The alarm includes a text prompt "good road surface, not suitable for long time off-road mode" and a "beep" prompt sound, and the prompt includes a text prompt "off-road mode has exited" and a "beep" prompt sound.

8. An automatic off-road mode exit control device for a vehicle based on the method of claims 1-7, characterized by: It includes a steering control unit, a rain sensor, a vehicle networking unit, a vehicle-mounted camera, an image processing unit, a main control unit, a CAN bus, an off-road mode control unit, and a four-wheel drive system assembly. The steering control unit is used to obtain the steering angle signal of the vehicle steering wheel and transmit the signal to the main control unit. The rain sensor is used to obtain information on whether it is currently raining or snowing and transmit the signal to the main control unit. The vehicle networking unit is used to connect to the network to obtain the vehicle's location information and the weather information at the current location, and transmit the signal to the main control unit. The vehicle-mounted camera is used to collect images of the vehicle's driving road surface and transmit the images to the image processing unit. The image processing unit is used to process the images collected by the vehicle-mounted camera to obtain the characteristic parameters of the driving road surface. The main control unit is used to receive signals and issue commands to the off-road mode control unit through the CAN bus to control the mode of the four-wheel drive system assembly.

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