CN111439198B - Method and system for large-scale vehicle turning warning - Google Patents

Abstract

The invention relates to a turning early warning method and a turning early warning system for a large vehicle. After obtaining this range, body control module BCM uses the indicator light strip to identify the road width range that will occupy on the ground. And starting the radar combined module to detect the obstacle on the inner side of the steering and determine the position, and if the obstacle exists in the road width range to be occupied, the BCM sends a prompt tone to remind a driver of paying attention to avoidance. The invention can clearly mark the road surface which the large vehicle is going to pass through, and effectively remind surrounding vehicles and pedestrians to avoid.

Description

Method and system for large-scale vehicle turning warning

technical field

The invention belongs to the field of large vehicle turning early warning systems, and in particular relates to a large vehicle turning early warning method and system.

Background technique

When a large vehicle is turning, the running tracks of the front and rear wheels are different, and the rear wheels do not follow the track of the front wheels, and a deviation will occur. This deviation is called the inner wheel difference. The greater the length of the vehicle, the greater the resulting inner wheel differential. In truck accidents, the accidents caused by the inner wheel difference account for a large proportion. When the truck is turning, if the pedestrians or vehicles on the turned side are relatively close, accidents may occur where the front of the vehicle does not collide but the rear of the vehicle collides, and the middle and rear of the vehicle are in the driver's visual blind spot. Unable to respond to emergencies in time, leading to serious traffic accidents.

With the continuous development of sensor and single-chip control technology, non-contact detection technology has been widely used in many fields. Radar ranging has the advantages of working around the clock and is suitable for short-distance and high-precision ranging in harsh environments, but it is easily interfered by electromagnetic waves. Laser ranging has the advantages of high directivity, high monochromaticity, high brightness, and fast measurement speed, especially has a certain penetration ability to rain and fog, and has strong anti-interference ability, but its cost is high and data processing is complicated. Ultrasonic ranging can directly measure short-distance targets, with high vertical resolution, wide application range, strong directionality, and has the advantages of not being affected by light, smoke, electromagnetic interference and other factors, and has a large coverage.

There is no domestic early warning system for the characteristics of the inner wheel difference when turning, and there is no active warning system for surrounding vehicles and pedestrians.

Contents of the invention

In view of the above existing problems, the present invention provides a large vehicle turning warning method and system, which are used to realize the lighting sign of the road occupied by the large vehicle when turning, and to warn the driver of the large vehicle when there is an obstacle on the turning road of the large vehicle. Audible warning.

In order to achieve the above object, the specific technical solution of the present invention is as follows: a large vehicle turning early warning method, comprising the following steps:

1) The driver turns on the turn signal, and the electronic control unit ECU turns on the large vehicle turning warning system;

2) Determine the driver's driving intention and the opening mode of the indicator light belt, that is, the electronic control unit ECU obtains the steering wheel steering angle and GPS positioning information through the CAN bus, judges the driver's driving intention, and determines the opening mode of the indicator light belt; wherein, the driver The driving intention includes two kinds of lane changing and turning; the said indicator light belt opening mode includes a left opening mode and a right opening mode;

3) Construct a road width calculation model based on linear two degrees of freedom; said road width calculation model based on linear two degrees of freedom includes: center of mass side slip angle β, front wheel speed direction and longitudinal angle ε, rear wheel side Declination angle α ₂ and turning radius R of the inner rear wheel;

4) Determine the road width range that the vehicle is about to occupy, that is, the curved triangle area formed by the arc with R as the radius, the turning center O as the center of the circle, the inner body, and the extension line on the inner side of the front axle is the road width range that the vehicle is about to occupy ;

5) Use the lighting module to illuminate the road width range that the vehicle will occupy, that is, the electronic control module ECU calculates the angle of the first row of indicator lights used to trace the boundary of the road width range, and sends the angle data to the body control module BCM, The body control module BCM controls the light strip to trace the boundary of the occupied road width range, and the other lights fill the remaining occupied road width area;

6) Determine whether there is an obstacle on the inner side of the vehicle steering, if there is an obstacle, go to step 7), otherwise go to step 8), wherein, the method of judging whether there is an obstacle on the inner side of the vehicle steering is: use the radar combination module to detect the obstacle on the inner side To detect, if the ultrasonic sensor receives the echo, it means that there is an obstacle on the inner side of the steering;

7) Determine whether the obstacle is within the range of the road to be occupied by the vehicle. If the obstacle is within the range of the road to be occupied by the vehicle, the electronic control unit ECU sends an instruction to the body control module BCM to control the audio generator to emit a prompt sound, Warn the driver to pay attention to avoiding, go to step 2), otherwise go to step 8);

8) Detect whether the turn signal is off, if not, go to step 2), otherwise go to step 9);

9) Turn off the large vehicle turning warning system.

Further, in the above step 1), the large vehicle turn warning system includes: GPS positioning module, radar combination module, six-axis sensor, steering wheel angle sensor, electronic control unit ECU, body control module BCM, lighting module, audio generator, CAN Bus and vehicle speed sensor; Among them, the electronic control unit ECU is used to obtain signals from the GPS positioning module, six-axis sensor, and steering wheel angle sensor through the CAN bus, determine the driver's driving intention, and calculate the road width occupied by the vehicle to complete the current action. The control unit ECU is also used to read the information of the radar combination module from the CAN bus to determine whether there are obstacles within the occupied road width; the body control module BCM is used to read the switch status of the turn signal control system from the light module, It is used to communicate with the electronic control unit ECU through the CAN bus to obtain the occupied road width range, to control the lighting module to use the side indicator light strip to mark the range on the road surface, and to obtain the judgment result of whether there are obstacles within the occupied range. Determine whether to control the audio generator to remind the driver; the radar combination module is composed of ultrasonic sensors, which are used to collect data, determine whether obstacles are detected, and calculate the coordinates of obstacles relative to large vehicles.

Further, in the above step 2), the method for judging the driver's intention is: when the vehicle is in the straight lane and the steering wheel angle is small, it is judged that the driver's intention is to change lanes, otherwise it is judged that the driver's intention is to turn; The method for determining the belt-on mode is as follows: when the driver intends to turn, determine the indicator belt-on mode according to the turn-on direction of the turn signal. When changing lanes, the turning on mode of the indicator light is determined by the positive or negative angle of the steering wheel. When the turning angle of the steering wheel is positive, the turning on mode of the indicator light is the left turning mode, otherwise it is the right turning mode.

Further, in the above step 3), the formula for calculating the center of mass sideslip angle β parameter is as follows:

Wherein u is the longitudinal velocity component of the vehicle, and v is the lateral velocity component of the vehicle, which is obtained by the vehicle speed sensor and the six-axis sensor; the calculation formula of the angle ε parameter between the front wheel velocity direction and the longitudinal direction is as follows:

Wherein w _r is the yaw rate of the car, obtained by a six-axis sensor, and a is the longitudinal distance from the front axle to the center of mass of the car; the formula for calculating the rear wheel slip angle _α parameter is as follows:

Wherein b is the longitudinal distance from the rear axle to the center of mass of the car; the formula for calculating the turning radius R parameter of the inner rear wheel is as follows:

where L is the wheelbase of the vehicle.

Further, in the above step 5), the formula for calculating the angle of the first row of indicator lights is as follows:

Among them, θ _n is the angle of the first row of indicator lights, n is the serial number of the first row of indicator lights, N is the total number of the first row of indicator lights on one side minus one, and I _n is the distance from the obtained road width range to the vehicle , h _light is the height of the indicator light from the ground.

Compared with the prior art, the present invention can warn surrounding pedestrians and vehicles to pay attention to the turning of large vehicles, and solves the problem that nearby pedestrians and vehicles misjudge the turning coverage of large trucks, resulting in the problem of insufficient avoidance; obstacles can appear in the blind area inside the turning Reminds the driver when there is an object, reducing the accidents caused by the lack of information in the blind area of the steering field when large vehicles are turning.

Description of drawings

Fig. 1 is a logical schematic diagram of the turning warning system for large vehicles of the present invention.

Fig. 2 is a flow chart of the large vehicle early warning method of the present invention.

Figure 3 is the calculation model of the occupied road width range.

Figure 4 is a schematic diagram of the occupied road width.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. It should be pointed out that the technical solution and design principles of the present invention will be described in detail below only with an optimized technical solution, but the protection scope of the present invention does not limited to this.

The large vehicle turn warning system shown in Figure 1 includes GPS positioning module, radar combination module, six-axis sensor, steering wheel angle sensor, electronic control unit ECU (Electronic Control Unit), body control module BCM (Body Control Module), lighting module, audio generator, CAN bus, and vehicle speed sensor; wherein, the electronic control unit ECU is used to obtain signals from the GPS positioning module, six-axis sensor, and steering wheel angle sensor through the CAN bus to determine the system operating mode (turning or changing lanes), and Calculate the road width occupied by the vehicle to complete the current action, the electronic control unit ECU is also used to read the information of the radar combination module from the CAN bus, and judge whether there are obstacles (pedestrians, vehicles) within the occupied road width; the body control The module BCM is used to read the switch status of the turn signal control system from the light module, and to communicate with the electronic control unit ECU through the CAN bus to obtain the occupied road width, and to control the light module to use the side indicator light belt to mark the range on the road surface , is also used to obtain the judgment result of whether there is an obstacle within the occupied range, and determine whether to control the audio generator to remind the driver; the radar combination module includes several on both sides of the vehicle body (3 to 5 on one side, depending on the length of the vehicle body) These sensors are composed of ultrasonic sensors. These sensors have the same height from the ground, and the distribution distance on each side is equal. They are controlled by time-division multiplexing method, that is, one runs after another is completed to avoid mutual interference. Their measurement range is set at the farthest About three meters, it is distributed in a cone shape, so that most of the range on the side of the car can be covered by the detection range of two ultrasonic sensors at the same time. The radar combination module is used to control the ultrasonic sensors to work in sequence, and integrate the data collected by them to determine whether an obstacle is detected, and to calculate the coordinates of the obstacle relative to the large vehicle.

As shown in Figure 2, the control method of the above-mentioned large vehicle turning warning system includes:

1) When the driver turns on the turn signal, the electronic control unit ECU turns on the large vehicle turn warning system;

2) Determine the driver's driving intention and the on-mode of the indicator light belt, that is, the electronic control unit ECU obtains the steering wheel steering angle and GPS positioning information through the CAN bus, judges the driver's driving intention, and determines the on-mode of the indicator light belt; among them, the driver's driving intention Including lane changing and turning; the indicator light belt opening mode includes the left opening mode and the right opening mode; the judgment method of the driver's intention is: when the vehicle is in the straight lane and the steering wheel angle is small, it is judged that the driver's intention is to change lanes , otherwise it is judged that the driver’s intention is to turn; the determination method of the indicator belt opening mode is as follows: when the driver’s intention is to turn, determine the indicator belt opening mode according to the direction of turning on the turn signal, when turning left, it is the left opening mode, and when turning right is the right-on mode; when the driver intends to change lanes, the light-on mode is determined by the positive or negative of the steering wheel angle. When the steering wheel angle is positive, the light-on mode is the left-side on mode, otherwise Open mode on the right;

3) Construct a road width calculation model based on linear two degrees of freedom; as shown in Figure 3, the road width calculation model based on linear two degrees of freedom includes: center of mass side slip angle β, front wheel speed direction and longitudinal angle e , the rear wheel side slip angle α ₂ and the turning radius R parameter of the inner rear wheel; the calculation method of each parameter is as follows:

The formula for calculating the center of mass sideslip angle β parameter is as follows:

Among them, u is the longitudinal velocity component of the vehicle, and v is the lateral velocity component of the vehicle, obtained through the vehicle speed sensor and the six-axis sensor;

The calculation formula of the angle ε between the speed direction of the front wheel and the longitudinal direction is as follows:

Where w _r is the yaw rate of the car, which is obtained by the six-axis sensor, and a is the longitudinal distance from the front axle to the center of mass of the car;

The calculation formula of rear wheel slip angle _α2 parameter is as follows:

Where b is the longitudinal distance from the rear axle to the center of mass of the vehicle;

The formula for calculating the turning radius R parameter of the rear wheel turning to the inside is as follows:

Where L is the wheelbase of the vehicle, and x is the longitudinal distance from the steering center to the rear axle of the vehicle;

4) Determine the road width range that the vehicle is about to occupy, that is, the curved triangle area formed by the arc with R as the radius, the turning center O as the center of the circle, the inner body, and the extension line on the inner side of the front axle is the road width range that the vehicle is about to occupy ; As shown in Figure 3, the curved triangle PQM area is the road width range that the vehicle will occupy.

5) Use the lighting module to illuminate the road width range that the vehicle will occupy, that is, the electronic control module ECU calculates the angle of the first row of indicator lights used to trace the boundary of the road width range, and sends the angle data of the indicator lights to the body control module BCM , the body control module BCM controls the light strip to trace the boundary of the occupied road width range, and the remaining indicator lights fill the remaining occupied road width area. The formula for calculating the angle of the first row of indicator lights is as follows:

Among them, θ _n is the angle of the first row of lights, n is the serial number of the first row of lights, N is the total number of the first row of lights on one side minus one, l _n is the distance from the obtained road width to the vehicle , h _light is the height of the indicator light from the ground.

6) Determine whether there is an obstacle on the inner side of the vehicle steering, if there is an obstacle, go to step 7), otherwise go to step 8), wherein, the method of judging whether there is an obstacle is: use the radar combination module to detect the obstacle on the inner side, If the ultrasonic sensor receives an echo, it means that there is an obstacle on the inside of the steering.

7) Determine whether the obstacle is within the range of the road to be occupied by the vehicle. If the obstacle is within the range of the road to be occupied by the vehicle, the electronic control unit ECU sends an instruction to the body control module BCM to control the audio generator to emit a prompt sound, Warn the driver to pay attention to avoidance, turn to step 2), otherwise turn to step 8), wherein, the judgment method is: each ultrasonic sensor that collects the echo in the radar combination module records the detection time, calculates the distance from the obstacle respectively, The radar combination module combines the distance obtained by multiple ultrasonic sensors to calculate the instantaneous position coordinates of the obstacle relative to the large vehicle, and upload it to the CAN bus. The electronic control unit ECU obtains the coordinates of the obstacle via the CAN bus, and compares it with the range of the road to be occupied by the vehicle to determine whether the detected obstacle is within the range of the occupied road. Establish a coordinate axis, take the rear wheel on the inside of the steering as the origin, the longitudinal direction of the car is the x-axis, pointing to the forward direction, and the y-axis is perpendicular to the car body, pointing to the inside of the steering. The formula for calculating the Y coordinate of the obstacle is as follows:

Among them, D _k is the distance measured by the ultrasonic sensor, k is the serial number of the sensor, B is the interval between two consecutive sensors, and M is the total number of ultrasonic sensors on one side minus one; the calculation formula of the abscissa X is:

8) Detect whether the turn signal is off, if not, go to step 2), otherwise go to step 9);

9) Turn off the large vehicle turning warning system.

As shown in Figure 4, the left figure shows the occupied road width when turning. As the steering angle increases, remains constant and decreases, the occupied road area of each cycle also increases, remains constant and decreases, and finally The shaded part in the left picture will be formed, which is the area swept by the indicator light; the right part is the road width occupied when changing lanes. The lane changing process can be divided into three parts: turning, going straight and reverse turning. The steering angle will change from 0 Increase and then decrease to 0, then increase in reverse and then decrease to 0, forming the shaded part in the right figure.

The above-described embodiments are only described to the preferred implementation of the present invention, and are not intended to limit the concept and scope of the present invention. Various modifications and improvements made should fall within the protection scope of the present invention.

Claims (5)

1. A turning early warning method for a large vehicle is characterized by comprising the following steps:

1) The driver turns on the steering lamp, and the electronic control unit ECU turns on the large vehicle turning early warning system;

2) Determining a driver driving intention and an indication lamp belt opening mode, namely acquiring a steering angle of a steering wheel and GPS positioning information by an Electronic Control Unit (ECU) through a Controller Area Network (CAN) bus, judging the driver driving intention, and determining the indication lamp belt opening mode; wherein the driver driving intention comprises two types of lane changing and turning; the indicating lamp belt opening mode comprises a left opening mode and a right opening mode;

3) Constructing a road width range calculation model based on linear two-degree-of-freedom; the road width range calculation model based on the linear two-degree-of-freedom comprises the following steps: centroid slip angle beta, included angle epsilon between front wheel speed direction and longitudinal direction, and rear wheel slip angle alpha ₂ And a turning inside rear wheel turning radius R;

4) Determining the road width range to be occupied by the vehicle, namely determining a curve triangular area formed by an arc taking R as the radius and taking a steering center O as the circle center and extension lines of the inner vehicle body and the front axial inner side as the road width range to be occupied by the vehicle;

5) Illuminating a road width range to be occupied by a vehicle by using a light module, namely calculating the angle of a first row of indicator lamps for tracing the boundary of the road width range by using an electronic control module (ECU), sending angle data to a Body Control Module (BCM), controlling the lamp to trace the boundary of the road width range by the Body Control Module (BCM), and filling the remaining road width occupied area by using the rest indicator lamps;

6) Judging whether an obstacle exists on the turning inner side of the vehicle, if so, turning to the step 7), otherwise, turning to the step 8), wherein the method for judging whether the obstacle exists on the turning inner side of the vehicle comprises the following steps: detecting an obstacle on the inner side of the steering by using a radar combined module, and if an ultrasonic sensor receives an echo, indicating that the obstacle exists on the inner side of the steering;

7) Judging whether the obstacle is in a road width range to be occupied by the vehicle, if so, sending an instruction to a vehicle body control module BCM by an electronic control unit ECU (electronic control Unit), controlling an audio generator to send a prompt tone, warning a driver to avoid, and turning to the step 2), otherwise, turning to the step 8);

8) Detecting whether the steering lamp is turned off, if not, turning to the step 2), otherwise, turning to the step 9);

9) Closing the turn early warning system of the large vehicle;

in the step 7), the method for judging whether the obstacle is in the road width range to be occupied by the vehicle comprises the following steps: each ultrasonic sensor which acquires echoes in the radar combination module records detection time, calculates the distance between each ultrasonic sensor and a barrier, calculates the instantaneous position coordinate of the barrier relative to a large vehicle by combining the distances obtained by the plurality of ultrasonic sensors in the radar combination module, and uploads the instantaneous position coordinate to a CAN bus; the electronic control unit ECU acquires coordinates of the obstacles through the CAN bus, compares the coordinates with a road width range to be occupied by the vehicle, and judges whether the detected obstacles are in the road width range to be occupied or not;

the obstacle ordinate Y is calculated as follows:

wherein D is _k Is the distance measured by the ultrasonic sensor, k is the serial number of the sensor, B is the connectionThe interval between two sensors is continued, M is the total number of the ultrasonic sensors on one side minus one;

the calculation formula of the horizontal coordinate X of the obstacle is as follows:

2. the large vehicle turning warning method according to claim 1, wherein in the step 2), the method of determining the driver's intention is: when the vehicle is in a straight lane and the steering wheel has a small rotation angle, judging that the intention of the driver is lane change, otherwise, judging that the intention of the driver is steering; the method for determining the starting mode of the indicator light band comprises the following steps: when the intention of a driver is steering, determining an indicator light band starting mode according to the starting direction of a steering lamp, wherein the indicator light band starting mode is a left-side starting mode when the driver turns left, and the indicator light band starting mode is a right-side starting mode when the driver turns right; when the intention of a driver is lane changing, the starting mode of the indicator light band is determined through the positive and negative of the steering wheel corner angle, when the steering wheel corner angle is positive, the starting mode of the indicator light band is a left side starting mode, and otherwise, the starting mode is a right side starting mode.

3. The large vehicle turning warning method according to claim 1, wherein in the step 3), the centroid slip angle β parameter is calculated as follows:

wherein u is the longitudinal speed component of the automobile, v is the transverse speed component of the automobile, and the transverse speed component is obtained by a speed sensor and a six-axis sensor; the calculation formula of the parameter of the included angle epsilon between the speed direction of the front wheel and the longitudinal direction is as follows:

wherein w _r The yaw angular velocity of the automobile is obtained through a six-axis sensor, and a is the longitudinal distance from a front shaft to the mass center of the automobile; side slip angle alpha of the rear wheel ₂ The parameter calculation formula is as follows:

wherein b is the longitudinal distance from the rear axle to the center of mass of the automobile; the calculation formula of the turning radius R parameter of the rear wheel at the inner side of the steering wheel is as follows:

wherein L is the wheelbase of the automobile.

4. The large vehicle turning warning method according to claim 1, wherein in the step 5), the angle calculation formula of the first row of indicator lamps which delineate the boundary of the road width range is as follows:

wherein, theta _n For the angle of the first row of indicating lamps, N is the serial number of the first row of indicating lamps, N is the total number of the first row of indicating lamps on one side minus one, and l _n For the distance from the road width range to the vehicle, h _light The height of the light above the ground is indicated.

5. The large-scale vehicle turning early warning method according to claim 1, wherein the method is implemented based on a vehicle turning early warning system comprising: the system comprises a GPS positioning module, a radar combined module, a six-axis sensor, a steering wheel corner sensor, an Electronic Control Unit (ECU), a vehicle Body Control Module (BCM), a light module, an audio generator, a CAN bus and a vehicle speed sensor; the electronic control unit ECU is used for acquiring signals of the GPS positioning module, the six-axis sensor and the steering wheel corner sensor through the CAN bus, determining the driving intention of a driver, calculating the road width range occupied by the vehicle to finish the current action, reading the information of the radar combined module from the CAN bus, and judging whether an obstacle exists in the occupied road width range; the body control module BCM is used for reading the on-off state of a turn signal control system from a light module, communicating with an electronic control unit ECU through a CAN bus, acquiring an occupied road width range, controlling the light module to mark a range on a road surface by using a side indicating lamp belt, acquiring a judgment result of whether an obstacle exists in the occupied range, and determining whether to control an audio generator to remind a driver; the radar combined module consists of an ultrasonic sensor and is used for acquiring data, judging whether an obstacle is detected or not and calculating the coordinate of the obstacle relative to the large-sized vehicle.

Images