阅读说明：本技术 一种基于环境感知的车辆安全行驶警示系统 (Vehicle safety driving warning system based on environment perception ) 是由 杨昊 常琳 蒋华涛 陈大鹏 于 2021-10-08 设计创作，主要内容包括：本发明公开了一种基于环境感知的车辆安全行驶警示系统,涉及车辆技术领域,该系统包括接入车辆CAN总线的总控制单元,以及分别安装在车辆的各个车轮处的环境感知装置,对于每个环境感知装置,在车辆行驶过程中,胎内充电线圈与射频充电单元进行供电交互,胎内射频单元与射频充电单元进行数据交互,将车轮控制单元通过传感单元获取到的行驶状态数据传输给射频充电单元；总控制单元基于行驶状态数据结合车辆反馈的车载CAN数据,计算分析车辆行驶环境异常以及车辆自身是否存在异常,并在异常时及时警示,用于为驾车人员提供路面状况的感知,及时性、准确性和全面性都较高,以便及时调整行车状态,保证行车安全。(The invention discloses a vehicle safety driving warning system based on environment perception, which relates to the technical field of vehicles and comprises a master control unit connected to a vehicle CAN bus and environment perception devices respectively arranged at each wheel of a vehicle, wherein for each environment perception device, a charging coil in a tire and a radio frequency charging unit are used for power supply interaction in the driving process of the vehicle, the radio frequency unit in the tire and the radio frequency charging unit are used for data interaction, and driving state data acquired by the wheel control unit through a sensing unit are transmitted to the radio frequency charging unit; the master control unit calculates and analyzes whether the driving environment of the vehicle is abnormal or not and whether the vehicle is abnormal or not based on the driving state data and the vehicle-mounted CAN data fed back by the vehicle, and warns in time when the vehicle is abnormal, so that the driver CAN sense the road condition, and the timeliness, the accuracy and the comprehensiveness are higher, so that the driving state CAN be adjusted in time, and the driving safety CAN be ensured.)

1. A vehicle safe driving warning system based on environment perception is characterized by comprising a master control unit connected to a vehicle CAN bus and environment perception devices respectively arranged at each wheel of a vehicle; each environment sensing device comprises a radio frequency charging unit, a wheel control unit, an in-tire charging coil, an in-tire radio frequency unit and a sensing unit, a capacitor is arranged in the wheel control unit and used for supplying power, the radio frequency charging unit is arranged on a frame and positioned above a corresponding wheel, the in-tire charging coil and the in-tire radio frequency unit are respectively arranged in a tire of the corresponding wheel, the in-tire charging coil is connected with the wheel control unit for supplying power, the in-tire radio frequency unit is connected with the wheel control unit for data interaction, and the sensing unit is connected with the wheel control unit and uploads sensed running state data;

the radio frequency charging units in the four environment sensing devices are all connected with the master control unit, and in the running process of a vehicle, for each environment sensing device: when the charging coils in the tires rotate to the lower part of the corresponding radio frequency charging unit along with the wheels, the charging coils in the tires and the radio frequency charging unit supply power and are mutually stored in a capacitor built in the wheel control unit; when the in-tire radio frequency unit rotates to the position below the corresponding radio frequency charging unit along with the wheel, the in-tire radio frequency unit and the radio frequency charging unit perform data interaction, and the driving state data acquired by the wheel control unit through the sensing unit is transmitted to the radio frequency charging unit;

and each radio frequency charging unit transmits the acquired running state data to the master control unit, and the master control unit sends corresponding warning information when detecting that the running environment of the vehicle is abnormal based on the running state data acquired by each environment sensing device.

2. The system according to claim 1, wherein when the total control unit determines that there is at least one of vehicle slip, an abnormality in the road surface state of the current running road, and that the current running road belongs to a predetermined topography, based on the running state data acquired by the respective environment sensing devices, it determines that the vehicle running environment is abnormal.

3. The system according to claim 2, wherein the driving state data acquired by the general control unit through all the environment sensing devices comprises: attitude data detected by a gyroscope in the sensing unit, wherein the attitude data comprises three-axis data, namely a positive X axis in the visual front of a driver, a positive Y axis in the visual right direction of the driver and a positive Z axis in the vertical horizontal ground;

the master control unit determines a yaw angle of each corresponding wheel based on the attitude data of each environment sensing device, wherein the yaw angle of each wheel is an angle which is obtained by converting the attitude data detected by a gyroscope on the corresponding wheel into angle data through quaternion and rotates on an XY plane by taking a Z axis as a center; when it is determined that the yaw angles of the four wheels are within the predetermined error range and the attitude data of the four wheels are simultaneously increased or simultaneously decreased in the Y-axis direction, it is determined that there is a vehicle slip.

4. The system according to claim 3, wherein the driving state data acquired by the general control unit through all the environment sensing devices further comprises: noise data detected by the sound sensor in the sensing unit, humidity data detected by the humidity sensor in the sensing unit, and temperature data detected by the temperature sensor in the sensing unit, when it is determined that the vehicle is slipping:

when the humidity data is increased or the noise data is reduced, determining that the vehicle is hydroplaning; when the temperature data is lower than the temperature threshold value, the vehicle is determined to be slippery on the ice surface.

5. The system according to claim 2, wherein the driving state data acquired by the general control unit through all the environment sensing devices comprises: the stress data of the tire are acquired by strain gauges in the sensing units, and the strain gauges are arranged on the tire treads of the corresponding wheels;

when the master control unit detects that the tire stress data sensed by the four environment sensing devices exceeds the error range, the road surface state abnormity of the current driving road is determined, wherein the road surface state abnormity comprises road surface damage and/or road surface width smaller than the tire surface of a single tire.

6. The system according to claim 2, wherein the predetermined topography of the current driving road comprises a ponding topography, and the driving state data acquired by the general control unit through all the environment sensing devices comprises: noise data detected by a sound sensor in the sensing unit, and humidity data detected by a humidity sensor in the sensing unit;

and when the master control unit detects that the noise data falls and the humidity data rises, determining that the current driving road belongs to the ponding terrain.

7. The system according to claim 2, wherein the predetermined topography of the current driving road includes a sand topography and a mud topography, and the driving state data acquired by the general control unit through all the environment sensing devices includes: the attitude data comprises three-axis data, namely, humidity data detected by a humidity sensor in a sensing unit and attitude data detected by a gyroscope in the sensing unit, wherein the attitude data comprises three-axis data, namely, a positive X axis in front of the driver, a positive Y axis in the right direction of the front of the driver, and a positive Z axis in the vertical horizontal ground upward direction;

when the master control unit detects that the attitude data descends in the Z-axis direction, the slip rate rises and the humidity data is lower than the humidity threshold value, determining that the current driving road belongs to the sandy terrain;

and when the master control unit detects that the attitude data descends in the Z-axis direction, the slip rate rises and the humidity data is higher than the humidity threshold value, determining that the current driving road belongs to the muddy terrain.

8. The system of claim 7, wherein the sensing unit of at least one environmental sensor comprises a laser ranging sensor fixed on a motorized slide rail on the housing of the rf charging unit and facing vertically and horizontally downward, the wheel control unit of the environmental sensor controls the motorized slide rail to drive the laser ranging sensor to move to a first measuring position and measure a first distance to the ground through the laser ranging sensor, the wheel control unit controls the motorized slide rail to drive the laser ranging sensor to move to a second measuring position and measure a second distance to the ground through the laser ranging sensor, and the difference between the first distance and the second distance is transmitted to the general control unit as the wheel diameter, and the general control unit is based on the wheel diameter, Vehicle speed and wheel speed determine the slip rate.

9. The system according to claim 1, wherein the driving state data acquired by the general control unit through each environment sensing device comprises: the air pressure sensor in each environment sensing device is arranged in the tire of the corresponding wheel;

when the master control unit detects that the in-tire air pressure data of one wheel continuously decreases, determining that the corresponding wheel leaks air, and sending corresponding warning information; and when the master control unit detects that the in-tire air pressure data of one wheel is reduced to a preset air pressure value and then keeps unchanged, determining the bulge of the corresponding wheel and sending corresponding warning information.

10. The system according to claim 1, wherein the master control unit determines a current friction coefficient based on a vehicle speed change, determines a temperature corresponding to the current friction coefficient in a preset temperature change curve as a tire outer surface temperature, and/or determines a wear percentage corresponding to the current friction coefficient in a wear degree change curve to determine a tire wear degree, and sends out corresponding warning information when the tire outer surface temperature reaches an outer surface temperature threshold and/or the tire wear degree reaches a wear threshold.

Technical Field

The invention relates to the technical field of vehicles, in particular to a vehicle safety driving warning system based on environment perception.

Background

With the increase of the existing vehicles, the safety conditions of the drivers are concerned more and more, and in the driving process of the vehicles, the driving risks brought by other vehicles are encountered, and the driving paths are not good due to the environments such as night, heavy rain, mud-rock flow and the like, so that dangers are brought. At present, the traditional method mainly depends on the manual perception and judgment of the vehicle personnel, but the manual perception effect is poor, the timeliness is not realized, and the driving safety is difficult to ensure.

Disclosure of Invention

The invention provides a vehicle safety driving warning system based on environment perception aiming at the problems and technical requirements, and the technical scheme of the invention is as follows:

a vehicle safe driving warning system based on environment perception comprises a master control unit connected to a vehicle CAN bus and environment perception devices respectively arranged at each wheel of a vehicle; each environment sensing device comprises a radio frequency charging unit, a wheel control unit, an in-tire charging coil, an in-tire radio frequency unit and a sensing unit, a capacitor is arranged in the wheel control unit and used for supplying power, the radio frequency charging unit is arranged on the frame and positioned above the corresponding wheel, the in-tire charging coil and the in-tire radio frequency unit are respectively arranged in the tire of the corresponding wheel, the in-tire charging coil is connected with the wheel control unit for supplying power, the in-tire radio frequency unit is connected with the wheel control unit for data interaction, and the sensing unit is connected with the wheel control unit and uploads sensed running state data;

the radio frequency charging unit among four environment perception devices all connects total control unit, and at the vehicle in-process of traveling, to every environment perception device: when the charging coil in the tire rotates to the position below the corresponding radio frequency charging unit along with the wheel, the charging coil in the tire and the radio frequency charging unit are powered and interacted and stored in a capacitor built in the wheel control unit; when the in-tire radio frequency unit rotates to the position below the corresponding radio frequency charging unit along with the wheel, the in-tire radio frequency unit and the radio frequency charging unit perform data interaction, and the driving state data acquired by the wheel control unit through the sensing unit is transmitted to the radio frequency charging unit;

and each radio frequency charging unit transmits the acquired running state data to the master control unit, and the master control unit sends corresponding warning information when detecting that the running environment of the vehicle is abnormal based on the running state data acquired by each environment sensing device.

The beneficial technical effects of the invention are as follows:

the application discloses vehicle safety traffic warning system based on environmental perception utilizes all kinds of sensors, on the way vehicle goes, the road surface condition that initiative perception automobile body place, the tire condition, and the on-vehicle CAN data that combines the vehicle feedback, whether computational analysis vehicle driving environment is unusual and vehicle self exists unusually, and in time warn when unusual, a perception for providing road surface condition for driving personnel, the promptness, accuracy and comprehensiveness are all higher, so that in time adjust driving state, guarantee driving safety.

Drawings

Fig. 1 is a system configuration diagram of a vehicle safety driving warning system according to the present application.

Figure 2 is a schematic view of the installation of the rf charging unit, the in-tire charging coil, the in-tire rf unit at each wheel.

FIG. 3 is a schematic view of the mounting of strain gages for each tire surface.

Fig. 4 is a schematic view of the mounting of the laser ranging sensor on the housing of the rf charging unit.

Fig. 5 is a schematic information flow diagram of the vehicle safety driving warning system according to the present application, which implements different types of warnings based on collected data.

Detailed Description

The following further describes the embodiments of the present invention with reference to the drawings.

The application discloses vehicle safety traffic warning system based on environmental perception please refer to fig. 1, and this system is including the total control unit who inserts vehicle CAN bus to and install the environmental perception device in each wheel department of vehicle respectively, and total control unit CAN directly link the vehicle-mounted screen through vehicle CAN bus, and acquires the relevant CAN data of vehicle, and the instrument panel CAN be placed in total control unit.

As shown in fig. 1, each environment sensing device comprises a radio frequency charging unit, a wheel control unit, an in-tire charging coil, an in-tire radio frequency unit and a sensing unit, the radio frequency charging unit 1 is installed on the frame and located above the corresponding wheel, and the radio frequency charging unit is powered by a vehicle power supply system and connected with a master control unit for data interaction. As shown in fig. 2, the charging coils 2 in the tire and the radio frequency units 3 in the tire are respectively installed in the tire corresponding to the wheel and installed at different positions along the circumferential direction of the wheel, and when the wheel rotates, the charging coils 2 in the tire and the radio frequency units 3 in the tire rotate alternately to the lower part of the radio frequency charging unit 1 for interaction. The built-in capacitor of the wheel control unit is used for supplying power, and the tire inner charging coil 2 is connected with the wheel control unit for supplying power and storing electric energy in the capacitor. The in-tire radio frequency unit 3 is connected with the wheel control unit for data interaction. The sensing unit is connected with the wheel control unit and uploads the sensed driving state data.

The sensing unit of each environment sensing device at least comprises a gyroscope, a strain gauge and an air pressure sensor. The gyroscope is characterized in that the front of the driver is a positive X axis in a visual mode, the right side of the front of the driver in the visual mode is a positive Y axis, and the vertical horizontal ground is a positive Z axis. The strain gauges are arranged on the treads of corresponding wheels, specifically, as shown in fig. 3, three strain gauges 4 are arranged on the treads of each wheel, and the three strain gauges 4 are arranged in a staggered mode in the two sides and the middle area of the plane with the contact surface of the wheel. The air pressure sensor is arranged in the tire of the corresponding wheel.

In addition to the sensing devices included in the sensing units of each of the above-mentioned environment sensing devices, all of the environment sensing devices further include one or more of a sound sensor, a temperature sensor, a humidity sensor and a laser ranging sensor, each of which is included in one or more of the environment sensing devices, so that the four environment sensing devices may include the same or different sensors, and each of the environment sensing devices may also include all or part of the above-mentioned sensors. As shown in fig. 3, the laser distance measuring sensor 5 is fixed on an electric slide rail on the housing of the radio frequency charging unit 1 and is vertical to the horizontal ground and downward, the electric slide rail drives the laser distance measuring sensor 5 to move in the horizontal direction, a wheel is arranged under one part of the electric slide rail, and the ground is arranged under the other part of the electric slide rail, so that the laser distance measuring sensor 4 can be opposite to the wheel or the ground when the electric slide rail drives the laser distance measuring sensor 5 to move to different positions.

The gyroscope, the sound sensor, the temperature sensor and the humidity sensor can be arranged at corresponding wheels, the specific positions are not limited, and the wheel control unit and the components of the sensing unit can be actually integrated together and then fixed on the inner sides of the wheels by using hoops or fasteners to bypass spokes.

The working process of the vehicle safety driving warning system is as follows, please refer to the information flow diagram of fig. 5:

before the wheels do not rotate, the master control unit reads default data or data collected last before the wheels stop when driving last time from the wheel control units in the various environment sensing devices. In the running process of a vehicle, wheels start to rotate, and when the charging coils in the tires rotate to the lower side of the corresponding radio frequency charging unit along with the wheels, the charging coils in the tires and the radio frequency charging unit are powered and interacted and stored in a capacitor arranged in a wheel control unit, so that the environment sensing device is powered and started normally. The wheel control unit can acquire corresponding driving state data through the sensing unit, when the in-tire radio frequency unit rotates to the position below the corresponding radio frequency charging unit along with the wheel, the in-tire radio frequency unit and the radio frequency charging unit perform data interaction, and the driving state data acquired by the wheel control unit through the sensing unit is transmitted to the radio frequency charging unit.

The four radio frequency charging units transmit the acquired driving state data to the master control unit, the master control unit carries out calculation and analysis on the basis of the driving state data acquired by the environment sensing devices, when the abnormal driving environment of the vehicle is detected, corresponding warning information is sent out, for example, corresponding icons are displayed on a vehicle-mounted screen, and then, for example, an alarm can be sent out to the mobile phone app in a mode of vehicle-mounted Bluetooth and the like.

The environment sensing device sends driving state data to the master control unit according to the type of the built-in sensing unit, and the driving state data comprises the following data:

(1) and attitude data detected by a gyroscope in the sensing unit, wherein the attitude data comprises triaxial data taking the visual front of the driver as a positive X axis, the visual right side direction of the driver as a positive Y axis and the vertical horizontal ground direction as a positive Z axis.

(2) And tire stress data acquired by a strain gauge in the sensing unit.

(3) And intra-tire air pressure data detected by an air pressure sensor in the sensing unit.

(4) Noise data detected by a sound sensor in the sensing unit.

(5) Humidity data detected by a humidity sensor in the sensing unit.

(6) Temperature data detected by a temperature sensor in the sensing unit.

Wherein, it is comparatively special, the data that laser rangefinder sensor gathered are used for confirming the wheel diameter, then generally need not upload in real time to give total control unit, can only upload once when the electricity, then specific: the wheel control unit in the environment sensing device controls the electric sliding rail to drive the laser ranging sensor to move to a first measuring position and measure a first distance between the laser ranging sensor and the ground, the wheel control unit controls the electric sliding rail to drive the laser ranging sensor to move to a second measuring position and measure a second distance between the laser ranging sensor and the ground, and a difference value between the first distance and the second distance is uploaded to the main control unit as the diameter of the wheel.

Based on the data uploaded by the environment sensing device, the vehicle running environment abnormality which can be detected by the master control unit comprises: at least one of vehicle slip, road surface state abnormality of the current running road, and the fact that the current running road belongs to a predetermined topography, specifically:

firstly, the vehicle slips.

The master control unit determines a YAW angle YAW of each corresponding wheel based on the attitude data of each environment sensing device, wherein the YAW angle of each wheel is an angle which is obtained by converting the attitude data detected by the gyroscope on the corresponding wheel into angle data through quaternion and rotates on an XY plane by taking a Z axis as a center. When it is determined that the yaw angles of the four wheels are within the predetermined error range and the attitude data of the four wheels are simultaneously increased or simultaneously decreased in the Y-axis direction, it is determined that there is a vehicle slip.

Further, on the basis of the determination of the vehicle slip, when the humidity data increases or the noise data decreases, the vehicle is determined to be water slip. When the temperature data is lower than the temperature threshold value, the vehicle is determined to be slippery on the ice surface. Corresponding warning information may be issued for warning of the vehicle slip and may further warn of the slip category.

Secondly, the road surface state of the current driving road is abnormal.

The abnormal road surface state comprises the damage of the road surface and/or the width of the road surface smaller than that of a single vehicle tire, when partial area of the road surface collapses or cracks appear, or when the road surface is smaller than that of a single vehicle tire, such as a road section of a wood bridge and the like, because the vehicle tire is not completely contacted with the ground, the vehicle tire surface which is not contacted with the ground generates larger deformation than the vehicle tire surface which is contacted with the ground under the influence of the air pressure in the vehicle tire, and the vehicle tire stress data is larger than that of the vehicle tire on other tire surfaces. And when the master control unit detects that the stress data of the tires sensed by the four environment sensing devices exceeds the error range, determining that the road surface state of the current running road is abnormal.

Furthermore, because a plurality of strain gauges are arranged on each tire in a staggered mode in different areas, the stress of the tire in different areas of the wheel can be determined according to the installation position of the strain gauge, corresponding warning information is sent to warn that the stress is not applied to a certain area of a certain tire, for example, a wheel model is displayed on a vehicle-mounted screen, and the stress of a single tire is divided into the following parts in the vertical direction: the middle, left and right three zones, then appear red to the unstressed part.

And thirdly, the current driving road belongs to a preset terrain. The predetermined topography includes ponding topography, sandy topography, and muddy topography.

1. When the tire contacts with the surface of water, because water is different with the stereoplasm road surface material, the sound degree of inhaling of water is higher, and when going with the speed, the sound decibel of going under the surface of water is less, consequently detects when total control unit that noise data drops and humidity data rises, confirms that the road of traveling at present belongs to the ponding topography.

It should be noted that, during the driving process, due to the friction between the wheel pattern gap and the tire, a certain noise will be generated between the wheel and the road surface, when the road surface has water accumulation or is frozen, the noise data will be reduced due to the change of the material of the wheel contact surface, while the noise data of the dry road surface is greater than that of the water accumulation road surface, and the noise data of the water accumulation road surface is greater than that of the ice surface.

2. When the tire enters the sand for the first time, the tire can sink into the sand, and at the moment, a single tire runs into the sand from a hard road surface, and the Z-axis numerical value of the posture data of the tire suddenly drops. Due to loose sand, the slip rate is increased after the vehicle is driven in, the sand is dry, and the reading value of the humidity sensor is low. On the other hand, the same Z-axis is lowered and the slip ratio is increased in the mud land as in the sand land, but the humidity value is increased due to high moisture around the mud land.

Therefore, when the general control unit detects that the attitude data descends in the Z-axis direction, the slip rate rises and the humidity data is lower than the humidity threshold value, the current driving road is determined to belong to the sandy terrain. And when the master control unit detects that the attitude data descends in the Z-axis direction, the slip rate rises and the humidity data is higher than the humidity threshold value, determining that the current driving road belongs to the muddy terrain.

Wherein the master control unit determines the slip rate based on the wheel diameter, the vehicle speed and the wheel rotating speed, and the calculation formula isv_{Vehicle with wheels}Is the vehicle speed from the vehicle CAN bus,d is the wheel diameter, v, measured by a laser range sensor_{Rotating shaft}Is the wheel speed from the vehicle CAN bus.

Fourthly, based on the data uploaded by the environment sensing device, except that the abnormal running environment of the vehicle can be warned, the vehicle can also be warned when the wheel leaks air or bulges, and the method is specific:

when the tire is punctured by an external sharp object, the air in the tire leaks out, the air pressure is reduced, and when the master control unit detects that the air pressure data in the tire of one wheel continuously drops, the air leakage of the corresponding wheel is determined, and corresponding warning information is sent out.

When the tyre bulges, the volume of the tyre is increased, the tyre pressure is constant after being reduced to a certain level, therefore, when the master control unit detects that the air pressure data in the tyre of one wheel is reduced to a preset air pressure value and then is kept unchanged, the bulge of the corresponding wheel is determined, and corresponding warning information is sent out.

Besides the data uploaded by the environment sensing device for warning, the master control unit can also execute the following warnings, including:

the total control unit determines the current friction coefficient mu based on the vehicle speed change, specifically: when the vehicle runs at a constant speed, the influence of wind resistance is ignored, and the vehicle resistance F_{Resistance device}Equal to friction, by W ═ F_{Resistance device}V can obtain the vehicle resistance F when the vehicle is at a constant speed_{Resistance device}. During the acceleration process before the constant speed of the vehicle, the acceleration V2 accelerated from the speed V1 after the preset time interval t is recorded through the vehicle CAN bus, and the acceleration of the vehicle CAN be obtained by using the value of a ═ V2-V1)/t. Due to the vehicle tension F in the acceleration process of the automobile_{Pulling device}＝ma＝W/V-F_{Resistance device}The power W and the speed V CAN be obtained through a vehicle CAN bus, and the acceleration a and the vehicle resistance F when the vehicle is at a constant speed_{Resistance device}From this, the vehicle weight m can be calculated. Then from F_{Resistance device}The current friction coefficient μ can be calculated as μ gm.

And after the current friction coefficient mu is obtained, determining the temperature corresponding to the current friction coefficient in the preset temperature change curve as the outer surface temperature of the tire, and/or determining the wear percentage corresponding to the current friction coefficient in the wear degree change curve to determine the wear degree of the tire, and sending corresponding warning information when the outer surface temperature of the tire reaches the outer surface temperature threshold value and/or the wear degree of the tire reaches the wear threshold value.

The friction coefficients of the tires are different at different temperatures, when the temperature is higher than 30 ℃, the friction coefficients of the tires are reduced along with the increase of the temperature, when the temperature is lower than 30 ℃, the friction coefficients of the tires are increased along with the increase of the temperature, and the friction coefficients of the tires are different under different environments due to the fact that different tires are different. Therefore, based on actual test data for different types of tires, a temperature change curve is fitted in advance and prestored. The outer surface temperature of the tire corresponding to the current friction coefficient mu can be determined by combining the temperature change curve, displayed on a vehicle-mounted screen and sent out corresponding warning information when the outer surface temperature threshold is reached.

The wear degree change curve is a curve obtained by fitting according to historical data under similar temperature, road condition, tire rotating speed, vehicle speed and temperature in advance, the wear degree of the tire represented by different friction coefficients is reflected, the friction coefficient of a brand-new tire when running is calculated as 0 loss, the friction coefficient of a set tire when being scrapped is 100% loss, the wear percentage corresponding to the current friction coefficient mu can be determined by combining the wear degree change curve, the wear percentage is displayed on a vehicle-mounted screen, and corresponding warning information is sent out when the wear threshold is reached.

Sixth, based on the vehicle safety driving warning system of this application, can also be to the highest speed v of vehicle_maxAlarming to know the braking distanceWhen the current friction coefficient μ is obtained by the above method, it is known that the current acceleration is a ═ μ g, and the current acceleration is based on the preset braking distance D_BrakeAnd braking time t_BrakeThe maximum vehicle speed v can be obtained_maxAnd displaying the highest vehicle speed through a vehicle-mounted screen, or giving a warning when the vehicle speed reaches the highest vehicle speed.

What has been described above is only a preferred embodiment of the present application, and the present invention is not limited to the above embodiment. It is to be understood that other modifications and variations directly derivable or suggested by those skilled in the art without departing from the spirit and concept of the present invention are to be considered as included within the scope of the present invention.