阅读说明：本技术 一种限速识别及控制方法 (Speed limit identification and control method ) 是由 陈松 于 2021-05-10 设计创作，主要内容包括：本发明公开了一种限速识别及控制方法,基于当前路段上的道路限速牌上的限速值和限速补充信息判断当前路段上的理论限速值；基于车辆的转向灯状态和方向盘转角判断当前路段上的驾驶员期望路径轨迹；基于当前路段上的驾驶员期望路径轨迹判断和当前路段上的理论限速值获当前路段上的执行限速值；基于当前路段上的执行限速值和当前路段上的实际车速控制车辆加速或减速。本发明依靠车载摄像头,通过对车辆周边环境的检测,实时发送限速信息,并将限速信息传送给车速控制系统,对车辆车速进行控制,使车辆在不违反交通安全法规的前提下,达到最大通行速度。(The invention discloses a speed limit identification and control method, which is characterized in that a theoretical speed limit value on a current road section is judged based on a speed limit value and speed limit supplementary information on a road speed limit board on the current road section; judging a driver expected path track on a current road section based on the state of a steering lamp of the vehicle and the steering wheel angle; obtaining an execution speed limit value on the current road section based on the driver expected path track judgment on the current road section and the theoretical speed limit value on the current road section; and controlling the vehicle to accelerate or decelerate based on the execution speed limit value on the current road section and the actual vehicle speed on the current road section. The invention relies on the vehicle-mounted camera, through the detection to the surrounding environment of vehicle, send the speed-limiting information in real time, and convey the speed-limiting information to the speed control system, control the vehicle speed, make the vehicle reach the maximum traffic speed on the premise of not violating the traffic safety regulation.)

1. A speed limit identification and control method is characterized in that: judging a theoretical speed limit value on the current road section based on the speed limit value on the road speed limit board on the current road section and the speed limit supplementary information; judging a driver expected path track on a current road section based on the state of a steering lamp of the vehicle and the steering wheel angle; obtaining an execution speed limit value on the current road section based on the driver expected path track judgment on the current road section and the theoretical speed limit value on the current road section; and controlling the vehicle to accelerate or decelerate based on the execution speed limit value on the current road section and the actual vehicle speed on the current road section.

2. The speed limit identification and control method according to claim 1, characterized in that: the method for acquiring the upper speed limit value and the speed limit supplementary information of the road speed limit sign on the current road section comprises the following steps: acquiring a picture of a road speed limit board by using a vehicle-mounted camera; and carrying out black-and-white binarization processing on the road speed limit board picture to obtain a speed limit value and speed limit supplementary information on the road speed limit board.

3. The speed limit identification and control method according to claim 1, characterized in that: the speed limit supplementary information comprises Chinese characters, English characters, Arabic characters and special characters.

4. The speed limit identification and control method according to claim 3, characterized in that: the method for acquiring the Chinese characters on the road speed limit board on the current road section comprises the following steps: the method for acquiring the upper speed limit value and the speed limit supplementary information of the road speed limit sign on the current road section comprises the following steps: acquiring a picture of a road speed limit board by using a vehicle-mounted camera; carrying out black and white binarization processing on the road speed limit board picture; uniformly dividing a region containing Chinese characters into a plurality of small blocks, counting the number Nb of black pixels and the number Nw of white pixels in the region, and obtaining a ratio P1 (Nb/(Nb + Nw)) of black pixels and white pixels, and P2 (Nw/(Nb + Nw)); comparing P1 and P2 with the calibration ratio P of the supplementary information picture, respectively, when P-5% < (P1, P2) < P + 5%, acquiring the Chinese characters in the region, otherwise, filtering the Chinese characters in the region.

5. The speed limit identification and control method according to claim 4, characterized in that: the small blocks for dividing the region containing Chinese characters are square or prismatic or triangular or polygonal in shape.

6. The speed limit identification and control method according to claim 1, characterized in that: the method for judging the driver's expected path track on the current road section based on the state of the turn lamp and the steering wheel angle of the vehicle includes: acquiring the number N1 of lane lines on the right side of the vehicle; the driver's desired path trajectory is obtained based on the number N1 of lane lines, the steering wheel angle Ws, and the turning on and off of the right turn signal.

7. The speed limit identification and control method according to claim 6, characterized in that: the method for acquiring the number N1 of lane lines on the right side of the vehicle comprises the following steps: the method comprises the following steps that a vehicle-mounted camera acquires a road line picture in front of a vehicle and performs black and white binarization processing on the road line picture; when the picture on the right side of the vehicle-mounted camera has pixel jumping, the fact that a lane line exists on the right side is judged, and the number of jumping times is equal to the number N1 of the lane lines.

8. The speed limit identification and control method according to claim 6, characterized in that: when the right turn light is turned off, N1 is 1, and-2 degrees is less than Ws and less than 2 degrees, the driver is judged to expect to go straight; when the right turn light is turned on, N1 is 2 and Ws is more than 5 degrees, judging that the driver expects to change lane and go straight; when the right turn light is turned on, N1 is equal to 1, and Ws is larger than 5 degrees, the driver is judged to expect to drive into the ramp.

9. The speed limit identification and control method according to claim 1, characterized in that: based on that the driver expected path track on the current road section corresponds to the theoretical speed limit value on the current road section, the theoretical speed limit value on the current road section is equal to the execution speed limit value on the current road section; and filtering the theoretical speed limit value on the current road section based on the fact that the expected path track of the driver on the current road section does not correspond to the theoretical speed limit value on the current road section, wherein the theoretical speed limit value on the previous road section is equal to the execution speed limit value on the current road section.

10. The speed limit identification and control method according to claim 1, characterized in that: when the execution speed limit value is larger than the actual speed on the current road section, the system increases the torque of the engine within the range of the specified time T, so that the vehicle is accelerated to the execution speed limit value; when the execution speed limit value is less than the actual speed on the current road section, the system should reduce the engine torque within the specified time T range, and the vehicle is decelerated to the execution speed limit value based on two-stage deceleration control.

Technical Field

The invention belongs to the technical field of vehicle control, and particularly discloses a speed limit identification and control method.

Background

The vehicle speed control mainly depends on active operation after a driver identifies a road speed limit sign. When the driver is inattentive, tired driving or the human eyes are wrongly identified, and the road speed limit sign is missed to be identified, overspeed and even traffic safety accidents are easy to occur. In order to solve the technical problems, in the prior art, the current speed limit value of the lane is mainly identified through navigation and a camera so as to remind a driver of the current speed requirement. There are mainly the following problems: 1. the accuracy is not sufficient. The speed limit information should contain the supplementary information contents below. Because the supplementary information cannot be identified, or the system can prompt errors through an incomplete reasonable strategy (such as 60km/h of ramp speed limit, when the vehicle runs when the speed of the vehicle is higher than 40km/h of speed limit value, the system judges that the driver does not have the intention of descending the ramp). 2. The comfort and the safety are not enough. The system cannot automatically control the vehicle speed because the vehicle speed cannot be accurately judged.

The specification of the chinese invention patent CN109050529A discloses a cruise vehicle speed control device and method under a ramp scene, and the device includes a ramp scene storage module, a front road information obtaining module, a ramp scene judging module, a vehicle state obtaining module, a driver intention judging module, an acceleration obtaining module, and a vehicle speed control module. And the ramp scene judging module is used for judging whether the vehicle is in a ramp scene or not according to the front road information after the cruise target is lost and calling the historical vehicle state information. The acceleration obtaining module is used for obtaining acceleration according to historical vehicle state information or current vehicle state information. The driver intention judgment module is used for judging whether the vehicle turns. The vehicle speed control module is used for controlling the vehicle to accelerate according to the acceleration and the vehicle turning judgment result. The device can avoid sudden acceleration after the target is lost in the ramp scene, and improves driving safety and driving experience. The technical scheme has the defects that: the speed limit requirement of the road in front of the vehicle cannot be judged, so that the error recognition probability is reduced; and through the intervention judgment of the driver, the priority strategy of the driver is implemented, the function is timely and automatic, and the function convenience is ensured.

Further, the specification of chinese patent CN105206068A discloses a method for performing security coordination control in a confluence area of an expressway based on a car-to-car communication technology, which first determines the type of a vehicle B, and if the vehicle B is a large truck, calculates the time range of the vehicle B reaching the confluent area collision area according to the information of the vehicle B. And calculating speed intervals, namely minimum and maximum speed values, of the vehicle A reaching the conflict area range within the time range of the vehicle B by taking the time mushroom E of the vehicle B reaching the conflict area of the confluence area as a limiting condition. Then, the current traveling speed of the vehicle a is compared, and if the traveling speed of the vehicle a is within the speed range, the vehicle a and the vehicle B arrive at the collision area within the same time, and the speed of the vehicle a needs to be adjusted to avoid collision with the vehicle B. And finally, according to the driving direction distance of the vehicles, the optimal suggested speed expectation which avoids conflict and does not influence the traffic efficiency of the main road vehicle A and the ramp vehicle B can be obtained through calculation. The driver is reminded to drive the vehicle at the recommended speed by voice or text. The technical scheme has the following defects: the speed limit requirement of the road in front of the vehicle cannot be judged, so that the error recognition probability is reduced; and through the intervention judgment of the driver, the priority strategy of the driver is implemented, the function is timely and automatic, and the function convenience is ensured.

Disclosure of Invention

Aiming at the technical problems in the prior art, the invention provides a speed limit identification and control method, which is characterized in that a vehicle-mounted camera is used for detecting the surrounding environment of a vehicle, sending speed limit information in real time and transmitting the speed limit information to a vehicle speed control system to control the vehicle speed. The vehicle can reach the maximum traffic speed on the premise of not violating the traffic safety regulation.

The invention discloses a speed limit identification and control method, which is characterized in that a theoretical speed limit value on a current road section is judged based on a speed limit value and speed limit supplementary information on a road speed limit board on the current road section; judging a driver expected path track on a current road section based on the state of a steering lamp of the vehicle and the steering wheel angle; obtaining an execution speed limit value on the current road section based on the driver expected path track judgment on the current road section and the theoretical speed limit value on the current road section; and controlling the vehicle to accelerate or decelerate based on the execution speed limit value on the current road section and the actual vehicle speed on the current road section.

In a preferred embodiment of the present invention, the method for acquiring the speed limit value and the speed limit supplementary information on the speed limit sign on the current road segment comprises: acquiring a picture of a road speed limit board by using a vehicle-mounted camera; and carrying out black-and-white binarization processing on the road speed limit board picture to obtain a speed limit value and speed limit supplementary information on the road speed limit board.

In a preferred embodiment of the present invention, the speed limit supplementary information includes chinese characters, english characters, arabic characters, and special characters.

In a preferred embodiment of the present invention, the method for acquiring the Chinese characters on the speed limit sign of the road on the current road section comprises the following steps: the method for acquiring the upper speed limit value and the speed limit supplementary information of the road speed limit sign on the current road section comprises the following steps: acquiring a picture of a road speed limit board by using a vehicle-mounted camera; carrying out black and white binarization processing on the road speed limit board picture; uniformly dividing a region containing Chinese characters into a plurality of small blocks, counting the number Nb of black pixels and the number Nw of white pixels in the region, and obtaining a ratio P1 (Nb/(Nb + Nw)) of black pixels and white pixels, and P2 (Nw/(Nb + Nw)); comparing P1 and P2 with the calibration ratio P of the supplementary information picture, respectively, when P-5% < (P1, P2) < P + 5%, acquiring the Chinese characters in the region, otherwise, filtering the Chinese characters in the region.

In a preferred embodiment of the present invention, the shape of the small block for dividing the region containing the chinese character is a square or a prism or a triangle or a polygon.

In a preferred embodiment of the present invention, a method of determining a driver's desired path trajectory on a current road segment based on a turn signal state and a steering wheel angle of a vehicle includes: acquiring the number N1 of lane lines on the right side of the vehicle; the driver's desired path trajectory is obtained based on the number N1 of lane lines, the steering wheel angle Ws, and the turning on and off of the right turn signal.

In a preferred embodiment of the present invention, the method of acquiring the number of lane lines N1 on the right side of the vehicle comprises: the method comprises the following steps that a vehicle-mounted camera acquires a road line picture in front of a vehicle and performs black and white binarization processing on the road line picture; when the picture on the right side of the vehicle-mounted camera has pixel jumping, the fact that a lane line exists on the right side is judged, and the number of jumping times is equal to the number N1 of the lane lines.

In a preferred embodiment of the present invention, when the right turn light is off and N1 is 1 and-2 ° < Ws < 2 °, it is judged that the driver desires to go straight; when the right turn light is turned on, N1 is 2 and Ws is more than 5 degrees, judging that the driver expects to change lane and go straight; when the right turn light is turned on, N1 is equal to 1, and Ws is larger than 5 degrees, the driver is judged to expect to drive into the ramp.

In a preferred embodiment of the present invention, based on that the driver's expected path trajectory on the current road segment corresponds to the theoretical speed limit value on the current road segment, the theoretical speed limit value on the current road segment is equal to the execution speed limit value on the current road segment; and filtering the theoretical speed limit value on the current road section based on the fact that the expected path track of the driver on the current road section does not correspond to the theoretical speed limit value on the current road section, wherein the theoretical speed limit value on the previous road section is equal to the execution speed limit value on the current road section.

In a preferred embodiment of the present invention, when the execution speed limit is greater than the actual vehicle speed on the current road section, the system should increase the engine torque within the specified time T to accelerate the vehicle to the execution speed limit; when the execution speed limit value is less than the actual speed on the current road section, the system should reduce the engine torque within the specified time T range, and the vehicle is decelerated to the execution speed limit value based on two-stage deceleration control.

The invention has the beneficial effects that: the invention identifies the speed limit information through the camera and the supplementary information below the speed limit information, accurately judges the speed limit requirement of the road in front of the vehicle and reduces the error identification probability. The driver is reminded in time by monitoring the intention of the driver, the position of the vehicle and the speed limit information, the vehicle speed is controlled, two different acceleration and deceleration strategies are implemented, and the feet are released, so that the comfort and the safety of the driver are improved. Through the intervention judgment of the driver, the priority strategy of the driver is implemented, the function is timely and automatic, and the function convenience is ensured.

Drawings

FIG. 1 is a flow chart of a speed limit identification and control method of the present invention;

FIG. 2 is a schematic diagram of Chinese character recognition for a speed limit recognition and control method of the present invention;

FIG. 3 is a schematic diagram of a driver's expected path trajectory according to a speed limit recognition and control method of the present invention.

Detailed Description

The invention will now be described in further detail, including the preferred embodiments, with reference to the accompanying drawings and by way of illustration of some alternative embodiments of the invention. It is to be understood that the described embodiments are merely a few embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without any inventive step, are within the scope of the present invention.

Preferably, the theoretical speed limit value on the current road section is judged based on the speed limit value on the road speed limit board on the current road section and the speed limit supplementary information; judging a driver expected path track on a current road section based on the state of a steering lamp of the vehicle and the steering wheel angle; obtaining an execution speed limit value on the current road section based on the driver expected path track judgment on the current road section and the theoretical speed limit value on the current road section; and controlling the vehicle to accelerate or decelerate based on the execution speed limit value on the current road section and the actual vehicle speed on the current road section.

Preferably, the method for acquiring the upper speed limit value and the speed limit supplementary information of the road speed limit sign on the current road section comprises the following steps: acquiring a picture of a road speed limit board by using a vehicle-mounted camera; and carrying out black-and-white binarization processing on the road speed limit board picture to obtain a speed limit value and speed limit supplementary information on the road speed limit board.

Preferably, the speed limit supplementary information includes chinese characters, english characters, arabic characters, and special characters.

Preferably, the method for acquiring the Chinese characters on the road speed limit sign on the current road section comprises the following steps: the method for acquiring the upper speed limit value and the speed limit supplementary information of the road speed limit sign on the current road section comprises the following steps: acquiring a picture of a road speed limit board by using a vehicle-mounted camera; carrying out black and white binarization processing on the road speed limit board picture; uniformly dividing a region containing Chinese characters into a plurality of small blocks, counting the number Nb of black pixels and the number Nw of white pixels in the region, and obtaining a ratio P1 (Nb/(Nb + Nw)) of black pixels and white pixels, and P2 (Nw/(Nb + Nw)); comparing P1 and P2 with the calibration ratio P of the supplementary information picture, respectively, when P-5% < (P1, P2) < P + 5%, acquiring the Chinese characters in the region, otherwise, filtering the Chinese characters in the region.

Preferably, the shape of the small block for dividing the region containing the chinese character is a square or a prism or a triangle or a polygon.

Preferably, the method of determining the driver's desired path trajectory on the current road segment based on the turn signal state and the steering wheel angle of the vehicle includes: acquiring the number N1 of lane lines on the right side of the vehicle; the driver's desired path trajectory is obtained based on the number N1 of lane lines, the steering wheel angle Ws, and the turning on and off of the right turn signal.

Preferably, the method for acquiring the number N1 of lane lines on the right side of the vehicle comprises the following steps: the method comprises the following steps that a vehicle-mounted camera acquires a road line picture in front of a vehicle and performs black and white binarization processing on the road line picture; when the picture on the right side of the vehicle-mounted camera has pixel jumping, the fact that a lane line exists on the right side is judged, and the number of jumping times is equal to the number N1 of the lane lines.

Preferably, when the right turn light is off and N1 is 1 and-2 ° < Ws < 2 °, it is judged that the driver desires to go straight; when the right turn light is turned on, N1 is 2 and Ws is more than 5 degrees, judging that the driver expects to change lane and go straight; when the right turn light is turned on, N1 is equal to 1, and Ws is larger than 5 degrees, the driver is judged to expect to drive into the ramp.

Preferably, based on that the driver expected path track on the current road section corresponds to the theoretical speed limit value on the current road section, the theoretical speed limit value on the current road section is equal to the execution speed limit value on the current road section; and filtering the theoretical speed limit value on the current road section based on the fact that the expected path track of the driver on the current road section does not correspond to the theoretical speed limit value on the current road section, wherein the theoretical speed limit value on the previous road section is equal to the execution speed limit value on the current road section.

Preferably, when the execution speed limit value is larger than the actual speed of the vehicle on the current road section, the system increases the torque of the engine within the range of the specified time T, so that the vehicle is accelerated to the execution speed limit value; when the execution speed limit value is less than the actual speed on the current road section, the system should reduce the engine torque within the specified time T range, and the vehicle is decelerated to the execution speed limit value based on two-stage deceleration control.

The specific steps for realizing the invention comprise:

the system comprises a speed limit identification function and a speed limit control function. The speed limit identification function is mainly used for identifying the speed limit board on the road through the camera, and particularly distinguishing the ramp speed limit board on the road. And accurately judging the speed limit value which needs to be observed by the current vehicle. The speed limit control function is used for reminding a driver and automatically controlling the running speed of the vehicle by predicting the running track, the current position and the identified speed limit value of the vehicle. The speed limit recognition is that after the camera is powered on, a view picture in front of the vehicle is shot in real time. And analyzing the speed limit value of the speed limit board and the supplementary information such as the ramp below the speed limit board in the captured picture.

Step 1: and determining the position of the speed limit sign. The speed limit information of the national standard is composed of a red circle, a white background color and a black numerical value in the middle, and the camera carries out black-white binary classification on a red pixel and other color pixels. In an image, pixel values suddenly change at the boundary of a black area and a white area. The position coordinates of the picture pixels are recorded at this time. The leftmost side and the rightmost side of the recorded position coordinates are the length and the position of the speed limit sign, and the uppermost side and the lowermost side are the height and the position of the speed limit sign.

Step 2: and confirming the position of the speed limit supplementary information. The ramp supplementary information is generally in a shape of white background and black, and is placed under the speed limit sign. And step 1, positioning the position of the white bottom part of the supplementary information. It can be known that the information of the ramp, time, etc. of the supplementary information is in the positioning area.

And step 3: speed limit supplementary information content text isolation. The supplementary information generally consists of Chinese characters, English words, time and the like. The common phenomena are ramp, ramp and 9:00-16: 00. And (3) carrying out black-and-white binary distinguishing on the supplementary information area in the step (2) by the camera. The font is black and the supplemental information background is white. The camera sequentially detects pixel values in the area from top to bottom on the leftmost side, checks a column, moves to the right, and repeats the up-down detection. The position coordinates of the pixel discontinuities are recorded. It can be observed that if there is a sudden change in pixels during the detection of each column of pixels, it can be determined that the column region has supplemental information content. In the process of checking to the right in sequence, the pixel mutation disappears, and the supplementary information content disappears by judgment. The content of the supplementary information can be continuously distinguished and isolated according to the method. Such as separating the ramp into two text areas, "turn" and "track".

And 4, step 4: and confirming the content of the supplementary information. And (3) uniformly dividing the character distinguishing area in the step (3) into a plurality of small blocks, and counting the number Nb of black pixels and the number Nw of white pixels in the divided small block areas. The black and white pixel ratios P1, P2, Nb/(Nb + Nw) are calculated. When compared with the ratio P of the pictures storing the supplementary information in the system, P-5% < (P1, P2) < P + 5%, the system judges that the supplementary information exists in the front. The small blocks can be square or diamond, and different shapes can be verified mutually, so that the accuracy is improved.

And 5: and (5) confirming the speed limit value. The speed limit value of the current road speed limit board can be obtained by the same steps. The speed limit control system automatically adjusts the speed of the vehicle by judging the current speed and the current road speed limit value.

Step 6: and (6) path prediction. The system also performs black-and-white binarization processing through road line pictures grabbed in front. If the image on the right side of the camera has pixel jump, the right side is judged to have a lane line, and the jump frequency is the same as the number of lanes N1. The detection time is properly prolonged, and working conditions such as broken lines are avoided. For example, when the number of transitions is 1, it may be determined that the current lane is the rightmost lane. The system also detects the current vehicle turn signal status, and the steering wheel angle Ws. The system judges the path track expected by the driver through the detection.

When the right turn light is turned off, N1 is 1, -2 degrees < Ws < 2 degrees, the driver is judged to expect to go straight, and the system prompts that the speed limit value is 120 km/h. The following straight-driving diagram;

when the right turn light is turned on, N1 is 2, Ws is more than 5 degrees, the driver is judged to expect to change lanes to go straight, and the system prompts that the speed limit value is 120 km/h. Lane change driving diagram as follows;

when the right turn light is turned on, N1 is 1, Ws is more than 5 degrees, the situation that the driver expects to drive into the ramp is judged, and the system prompts that the speed limit value is 60 km/h.

And 7: speed limit reminding and control detection. When the speed limit signs on both sides of the road are identified, particularly when the supplementary information is identified under the speed limit signs, the system confirms whether to prompt a driver or prepare for speed limit control according to the steps. For example, when the system judges that the driver does not intend to drive into the ramp through the step 6, if the system identifies the speed limit value and the text supplementary information of the ramp is arranged below the speed limit value, the system can filter in time without prompting the ramp to limit the speed, and the system continues to drive according to the previous speed limit value. And when the speed limit sign is identified, the system can judge whether the current time needs speed limit reminding or control or not within a specified time.

And 8: and (5) speed limit control. The current real vehicle speed can be obtained through a wheel speed sensor. And amplifying the real vehicle speed into the vehicle speed of the instrument according to the set ratio. After the speed limit information which the vehicle needs to obey is obtained through the steps, the system compares the speed limit value V2 with the instrument vehicle speed V1. According to the comparison result, the system should divide the control into two states of acceleration and deceleration.

When V2 > V1, the system should increase engine torque to accelerate the vehicle to V2 within the specified time T. According to the formula V2-V1 + a T, the acceleration value required for controlling the vehicle speed is calculated.

When V2 < V1, the system should reduce the speed below the speed limit within the specified time T. According to the formula V2-V1T +1/2 a T²And calculating a deceleration value required by controlling the vehicle speed. The system is divided into two stages of deceleration control according to the deceleration value.

1. When the deceleration a is larger than a set value, the engine is reversely dragged only by stopping the oil injection of the engine, and the vehicle speed is reduced;

2. when the deceleration a is smaller than the set value, the system judges that the engine is reversely dragged and cannot reduce the vehicle speed within the set time, and the ESC intervenes at the moment, increases the pressure of the main cylinder, increases the deceleration value and reduces the vehicle speed.

Empirically, the typical predetermined time T of the system is 20s, and the deceleration set point is-0.35 m/s². If the speed limit value is 100km/h, the current instrumentThe vehicle speed is 80km/h, and the acceleration of the system at the moment is 0.28m/s². When the speed limit is 60km/h and the current instrument speed is 100km/h, the deceleration of the system at the moment is-0.56 m/s². If the deceleration is less than the set value, the master cylinder pressure should be increased by the ESC to increase the deceleration limit.

And step 9: the system exits. The system controls the speed of the vehicle until a new speed limit is identified. In the control process of the system, when the driver is detected to have the actions of actively operating the vehicle such as stepping on the brake, quickly rotating a steering wheel and the like, the requirement of taking over the vehicle by the driver is judged, or the current situation is urgent. At this point the system exits, being actively controlled by the driver.

The invention accurately identifies the speed limit value and the speed limit supplementary information on the ramp speed limit board; and judging the accurate speed limit requirement by identifying the position of the supplementary information and the content of the supplementary information. And controlling the vehicle speed in a grading way through an accurate speed limit value and a path track expected by a driver. CN105206068A discloses only that the time range of vehicle B reaching the merge area conflict area is taken as a limiting condition, and the speed interval, i.e. the minimum and maximum speed values, of vehicle a reaching the conflict area range within the time range of vehicle B is calculated, and no technical teaching is given, and the method is not a conventional technical means or a known technology in the field; meanwhile, the invention detects the state of the steering lamp and the steering wheel corner of the current vehicle through the road line picture captured in front, judges the expected path track of the driver, and further judges whether the current time needs speed limit reminding or control, wherein the control process comprises the step deceleration control and the step acceleration control; furthermore, the speed limit information and the supplementary information below the speed limit information are identified through the camera, and the speed limit requirement of the road in front of the vehicle is accurately judged through black-white binarization, so that the error identification probability is reduced; on the other hand, the driver is reminded in time by monitoring the intention of the driver, the position of the vehicle and the speed limit information, the vehicle speed is controlled, two different acceleration and deceleration strategies are implemented, and the feet are released, so that the improvement of the comfort and the safety of the driver is facilitated. Through the intervention judgment of the driver, the priority strategy of the driver is implemented, the function is timely and automatic, and the function convenience is ensured.

It should be noted that the black-and-white binarization method adopted in the present invention belongs to the prior art, and specifically can participate in a speed-limiting signboard recognition method combining machine learning and computer vision disclosed in the specification of the chinese patent invention CN 110334601A.

It should be understood that the above-mentioned embodiments are merely exemplary of the present invention, and not restrictive, and that any modifications, combinations, substitutions, improvements, etc. made within the spirit and scope of the present invention are included in the present invention.