阅读说明：本技术 电动车驾驶警示系统及方法、毫米波雷达系统及电动车 (Electric vehicle driving warning system and method, millimeter wave radar system and electric vehicle ) 是由 王姗 于 2020-12-31 设计创作，主要内容包括：本发明提供了一种电动车驾驶警示系统及方法、毫米波雷达系统及电动车,其中,电动车驾驶警示系统中包括：毫米波雷达系统,配置有相互连接的人员和车辆状态信息跟踪模块和前端射频模块；测速模块,用于实时测量电动车的运行速度；转向模块,用于实时探测电动车的转向角度和/或转向灯信号；报警模块,用于根据人员和车辆状态信息跟踪模块发送的报警信息进行警示；通信模块,分别与人员和车辆状态信息跟踪模块、测速模块、转向模块及报警模块连接。其对其相对电动车的速度、位置和运动目标的运动轨迹进行分析,判断出有潜在危险的目标物,以此电动车在行驶过程中,将分析信息反馈给驾驶员,警示驾驶员注意安全。(The invention provides an electric vehicle driving warning system and method, a millimeter wave radar system and an electric vehicle, wherein the electric vehicle driving warning system comprises: the millimeter wave radar system is provided with a personnel and vehicle state information tracking module and a front-end radio frequency module which are connected with each other; the speed measuring module is used for measuring the running speed of the electric vehicle in real time; the steering module is used for detecting the steering angle and/or the steering lamp signal of the electric vehicle in real time; the alarm module is used for carrying out warning according to alarm information sent by the personnel and vehicle state information tracking module; and the communication module is respectively connected with the personnel and vehicle state information tracking module, the speed measuring module, the steering module and the alarm module. The speed, the position and the motion trail of the moving target relative to the electric vehicle are analyzed, the target object with potential danger is judged, and therefore the electric vehicle feeds analysis information back to a driver in the driving process, and the driver is warned to pay attention to safety.)

1. An electric vehicle driving warning system, comprising:

the millimeter wave radar system is provided with a personnel and vehicle state information tracking module and a front end radio frequency module which are connected with each other, wherein the personnel and vehicle state information tracking module is used for processing received information and sending out corresponding warning, and the front end radio frequency module is used for receiving and sending millimeter wave signals towards the rear of the electric vehicle;

the speed measuring module is used for measuring the running speed of the electric vehicle in real time;

the steering module is used for detecting the steering angle and/or the steering lamp signal of the electric vehicle in real time;

the alarm module is used for carrying out warning according to the alarm information sent by the personnel and vehicle state information tracking module;

and the communication module is respectively connected with the personnel and vehicle state information tracking module, the speed measuring module, the steering module and the alarm module, and is used for sending the signals detected by the speed measuring module and the steering module to the personnel and vehicle state information tracking module for processing and sending the alarm information generated by the personnel and vehicle state information tracking module to the alarm module.

2. The electric vehicle driving warning system of claim 1, wherein the front-end radio frequency module is further configured to transmit and receive millimeter wave signals using an N-transmit M-receive MIMO radar system, mix the received millimeter wave signals with the transmitted millimeter wave signals, perform ADC sampling, and transmit the millimeter wave signals to the personnel and vehicle state information tracking module for processing.

3. The electric vehicle driving warning system of claim 1 or 2, wherein the personnel and vehicle status information tracking module comprises a radio frequency parameter adjusting module and a signal processing module, wherein,

the radio frequency parameter adjusting unit is used for configuring waveform parameters of millimeter wave signals sent by the front-end radio frequency module;

the signal processing module is used for processing the signals fed back by the front-end radio frequency module, the speed measuring module and the steering module to generate alarm information.

4. The electric vehicle driving warning system of claim 3, wherein the signal processing module comprises:

the calculation unit is used for processing the ADC sampling data sent by the front-end radio frequency module to obtain the distance between the front-end radio frequency module and a target object, the movement speed of the target object and the angle and speed of the target object relative to the electric vehicle;

the comparison unit is connected with the calculation unit and used for comparing the steering angle of the electric vehicle detected by the steering module with a preset angle threshold value and judging whether the electric vehicle needs to be steered or not; the device is used for comparing the calculated distance to the target object, the movement speed of the target object, the angle and the speed of the target object relative to the electric vehicle with preset corresponding threshold values and judging whether the steering condition is met;

the judging unit is respectively connected with the comparing unit and the calculating unit and is used for judging whether a dangerous target object exists behind according to the calculated distance between the judging unit and the target object, the movement speed of the target object and the angle and speed of the target object relative to the electric vehicle; the steering angle of the electric vehicle detected by the steering module is compared with a preset angle threshold value, and whether the electric vehicle needs to be steered or not is judged;

and the alarm information generating unit is used for generating corresponding alarm information according to the judgment result of the judging unit.

5. An electric vehicle driving warning method applied to the electric vehicle driving warning system according to any one of claims 1 to 4, the electric vehicle driving warning method comprising:

controlling the front-end radio frequency module to transmit millimeter wave signals towards the rear of the electric vehicle and receiving the returned millimeter wave signals;

receiving a signal obtained by mixing the received millimeter wave signal and the transmitted millimeter wave signal and then performing ADC (analog to digital converter) sampling by the front-end radio frequency module;

the communication module is used for receiving the running speed of the electric vehicle measured by the speed measuring module in real time;

receiving a steering angle and/or a steering lamp signal of the electric vehicle detected by a steering module in real time through a communication module;

and processing the received information and sending the warning information to the warning module for warning through the communication module.

6. The electric vehicle driving warning method of claim 5, wherein the processing the received information and sending the warning information to the warning module for warning via the communication module further comprises:

processing ADC sampling data sent by the front-end radio frequency module to obtain the distance between the front-end radio frequency module and a target object, the movement speed of the target object and the angle and speed of the target object relative to the electric vehicle;

comparing the steering angle of the electric vehicle detected by the steering module with a preset angle threshold value, and judging whether the electric vehicle needs to be steered;

if so, judging whether a dangerous target object exists behind according to the calculated distance between the electric vehicle and the target object, the movement speed of the target object and the angle and speed of the target object relative to the electric vehicle;

if not, further comparing the calculated distance to the target object, the movement speed of the target object, the angle and the speed of the target object relative to the electric vehicle with preset corresponding thresholds, and judging whether the steering condition is met;

and generating a warning signal according to the judgment result and sending the warning signal to the alarm module through the communication module.

7. The driving warning method for an electric vehicle as claimed in claim 6, wherein the step of determining whether a dangerous object exists behind the electric vehicle based on the calculated distance to the object, the moving speed of the object, and the angle and speed of the object relative to the electric vehicle comprises:

judging whether a collision risk exists between the target object and the electric vehicle or not according to the angle of the target object relative to the electric vehicle;

if yes, calculating the safe collision avoidance time TTC of the vehicle according to the calculated distance between the vehicle and the target object and the speed of the target object relative to the electric vehicle:

TTC＝ΔS/ΔV

wherein, Δ S is the distance between the electric vehicle and the target object, and Δ V is the speed of the target object relative to the electric vehicle;

calculating the vehicle distance early warning time HWM according to the calculated distance between the vehicle distance and the target object and the movement speed of the target object:

HWM＝ΔS/V₁

wherein, V₁The movement speed of the target object;

judging whether the calculated vehicle safe collision avoidance time TTC and the vehicle distance early warning time HWM are not smaller than a preset vehicle safe collision avoidance time threshold and a preset vehicle distance early warning threshold at the same time;

the target object is determined not to be a dangerous target object.

8. The electric vehicle driving warning method of claim 7, wherein the generating a warning signal according to the determination result and sending the warning signal to the alarm module through the communication module comprises:

when the dangerous target does not exist behind the alarm module, the alarm signal is sent to the alarm module to carry out green light prompt;

when the situation that the electric vehicle does not need to turn but a dangerous target object exists behind the electric vehicle is judged, a warning signal is sent to the alarm module to prompt a yellow light;

when the electric vehicle is judged to need to turn and a dangerous target object exists at the rear part, the warning signal is sent to the alarm module to prompt the red light.

9. A millimeter wave radar system comprising a single chip transmit antenna array, a receive antenna array, a front end radio frequency, a signal processor, a memory, and a computer program stored in the memory and executable on the processor, the computer program when executed implementing the steps of the method of electric vehicle driving alert of any of claims 5 to 8.

10. An electric vehicle, characterized in that at least one millimeter wave radar system according to claim 9 is provided in the electric vehicle; when a plurality of millimeter wave radar systems are configured, the millimeter wave radar systems are in communication connection with one another, and each millimeter wave radar performs fusion processing on detection information of other millimeter wave radars.

Technical Field

The invention relates to the technical field of detection, in particular to an electric vehicle driving warning system and method, a millimeter wave radar system and an electric vehicle.

Background

In recent years, with the ever-increasing environmental awareness and the strong national advocated, more and more people choose to use the electric vehicle to ride instead of walk, and the electric vehicle becomes an irreplaceable vehicle for people. This is accompanied by the safety problems in use of electric vehicles that many cities have come to notice and try to take certain measures to solve, such as: the helmet is required to be worn when the electric vehicle is driven, and people are forbidden to be driven when the electric vehicle is driven. Although this can reduce the safety problem that the electric motor car brought to people to a certain extent, still there is not more reliable scheme at present to driver's warning and protection in the driving process, for example: under the condition of bad weather, the visual field environment is very poor in rainy days or foggy days, and great interference is brought to the judgment of a driver; under the condition of night, the driving electric vehicle cannot observe pedestrians at the rear in time, so that accidents and the like are easy to happen.

For the detection of people and vehicles, technologies such as video computer vision, infrared, Wi-Fi and the like are commonly adopted at present, wherein although the vision technology can meet the detection of pedestrians and vehicles to a certain extent, the vision technology still cannot carry out effective identification under the condition of severe weather; the infrared detection distance is short and the cost is high; Wi-Fi technology is poor in positioning the direction of a positioning target object, and cannot meet the requirement for accurate positioning of a rear target object. Therefore, a method for accurately positioning and detecting pedestrians and vehicles in extreme weather is needed.

Disclosure of Invention

Aiming at the problems, the invention provides an electric vehicle driving warning system and method, a millimeter wave radar system and an electric vehicle, and effectively solves the technical problem that the existing method cannot accurately position and detect pedestrians and vehicles.

The technical scheme provided by the invention is as follows:

an electric vehicle driving warning system comprising:

the millimeter wave radar system is provided with a personnel and vehicle state information tracking module and a front end radio frequency module which are connected with each other, wherein the personnel and vehicle state information tracking module is used for processing received information and sending out corresponding warning, and the front end radio frequency module is used for receiving and sending millimeter wave signals towards the rear of the electric vehicle;

the speed measuring module is used for measuring the running speed of the electric vehicle in real time;

the steering module is used for detecting the steering angle and/or the steering lamp signal of the electric vehicle in real time;

the alarm module is used for carrying out warning according to the alarm information sent by the personnel and vehicle state information tracking module;

and the communication module is respectively connected with the personnel and vehicle state information tracking module, the speed measuring module, the steering module and the alarm module, and is used for sending the signals detected by the speed measuring module and the steering module to the personnel and vehicle state information tracking module for processing and sending the alarm information generated by the personnel and vehicle state information tracking module to the alarm module.

Further preferably, the front-end radio frequency module is further configured to send and receive millimeter wave signals by using an N-send M-receive MIMO radar system, mix the received millimeter wave signals with the sent millimeter wave signals, perform ADC sampling, and send the millimeter wave signals to the personnel and vehicle state information tracking module for processing.

Further preferably, the tracking module for the status information of the people and the vehicle comprises a radio frequency parameter adjusting module and a signal processing module, wherein,

the radio frequency parameter adjusting unit is used for configuring waveform parameters of millimeter wave signals sent by the front-end radio frequency module;

the signal processing module is used for processing the signals fed back by the front-end radio frequency module, the speed measuring module and the steering module to generate alarm information.

Further preferably, the signal processing module includes:

the calculation unit is used for processing the ADC sampling data sent by the front-end radio frequency module to obtain the distance between the front-end radio frequency module and a target object, the movement speed of the target object and the angle and speed of the target object relative to the electric vehicle;

the comparison unit is connected with the calculation unit and used for comparing the steering angle of the electric vehicle detected by the steering module with a preset angle threshold value and judging whether the electric vehicle needs to be steered or not; the device is used for comparing the calculated distance to the target object, the movement speed of the target object, the angle and the speed of the target object relative to the electric vehicle with preset corresponding threshold values and judging whether the steering condition is met;

the judging unit is respectively connected with the comparing unit and the calculating unit and is used for judging whether a dangerous target object exists behind according to the calculated distance between the judging unit and the target object, the movement speed of the target object and the angle and speed of the target object relative to the electric vehicle; the steering angle of the electric vehicle detected by the steering module is compared with a preset angle threshold value, and whether the electric vehicle needs to be steered or not is judged;

and the alarm information generating unit is used for generating corresponding alarm information according to the judgment result of the judging unit.

The invention also provides an electric vehicle driving warning method which is applied to the electric vehicle driving warning system and comprises the following steps:

controlling the front-end radio frequency module to transmit millimeter wave signals towards the rear of the electric vehicle and receiving the returned millimeter wave signals;

receiving a signal obtained by mixing the received millimeter wave signal and the transmitted millimeter wave signal and then performing ADC (analog to digital converter) sampling by the front-end radio frequency module;

the communication module is used for receiving the running speed of the electric vehicle measured by the speed measuring module in real time;

receiving a steering angle and/or a steering lamp signal of the electric vehicle detected by a steering module in real time through a communication module;

and processing the received information and sending the warning information to the warning module for warning through the communication module.

Further preferably, the processing the received information and sending the warning information to the warning module through the communication module for warning further includes:

processing ADC sampling data sent by the front-end radio frequency module to obtain the distance between the front-end radio frequency module and a target object, the movement speed of the target object and the angle and speed of the target object relative to the electric vehicle;

comparing the steering angle of the electric vehicle detected by the steering module with a preset angle threshold value, and judging whether the electric vehicle needs to be steered;

if so, judging whether a dangerous target object exists behind according to the calculated distance between the electric vehicle and the target object, the movement speed of the target object and the angle and speed of the target object relative to the electric vehicle;

if not, further comparing the calculated distance to the target object, the movement speed of the target object, the angle and the speed of the target object relative to the electric vehicle with preset corresponding thresholds, and judging whether the steering condition is met;

and generating a warning signal according to the judgment result and sending the warning signal to the alarm module through the communication module.

Further preferably, the determining, according to the calculated distance to the target object, the moving speed of the target object, and the angle and speed of the target object relative to the electric vehicle, whether a dangerous target object exists behind the electric vehicle includes:

judging whether a collision risk exists between the target object and the electric vehicle or not according to the angle of the target object relative to the electric vehicle;

if yes, calculating the safe Time-To-Collision Time TTC (Time-To-Collision) of the vehicle according To the calculated distance between the vehicle and the target object and the speed of the target object relative To the electric vehicle:

TTC＝ΔS/ΔV

wherein, Δ S is the distance between the electric vehicle and the target object, and Δ V is the speed of the target object relative to the electric vehicle;

calculating the distance warning time HWM (headway Monitoring warning) according to the calculated distance between the vehicle and the target object and the movement speed of the target object:

HWM＝ΔS/V₁

wherein, V₁The movement speed of the target object;

judging whether the calculated vehicle safe collision avoidance time TTC and the vehicle distance early warning time HWM are not smaller than a preset vehicle safe collision avoidance time threshold and a preset vehicle distance early warning threshold at the same time;

the target object is determined not to be a dangerous target object.

Further preferably, the generating a warning signal according to the determination result and sending the warning signal to the alarm module through the communication module includes:

when the dangerous target does not exist behind the alarm module, the alarm signal is sent to the alarm module to carry out green light prompt;

when the situation that the electric vehicle does not need to turn but a dangerous target object exists behind the electric vehicle is judged, a warning signal is sent to the alarm module to prompt a yellow light;

when the electric vehicle is judged to need to turn and a dangerous target object exists at the rear part, the warning signal is sent to the alarm module to prompt the red light.

The invention also provides a millimeter wave radar system, which comprises a single-chip transmitting antenna array, a receiving antenna array, a front-end radio frequency, a signal processor, a memory and a computer program which is stored in the memory and can be run on the processor, wherein when the computer program is executed, the steps of the electric vehicle driving warning method are realized.

The invention also provides an electric vehicle, wherein at least one millimeter wave radar system is configured in the electric vehicle; when a plurality of millimeter wave radar systems are configured, the millimeter wave radar systems are in communication connection with one another, and each millimeter wave radar performs fusion processing on detection information of other millimeter wave radars.

In the electric vehicle driving warning system and method, the millimeter wave radar system and the electric vehicle, the speed measuring module acquires the running speed of the electric vehicle in real time and provides the running speed to personnel in the millimeter wave radar system and the vehicle state information tracking module for processing, so that the relative speed of a target object can be more accurately and stably obtained; the steering module can simulate or provide the steering intention of the electric vehicle, and does not prompt the driver with interference under the condition of not needing lane change/turning. In addition, the target objects (pedestrians, vehicles, animals and the like) behind the electric vehicle can be monitored and tracked in real time, and the relative speed, position and motion trail of the target objects relative to the electric vehicle can be measured. The speed, the position and the motion trail of the moving target relative to the electric vehicle are analyzed, the target object with potential danger is judged, and therefore the electric vehicle feeds analysis information back to a driver in the driving process, the driver is warned to pay attention to safety, and warning is provided for safe driving of the driver especially under the condition of poor visual field conditions. Particularly, when lane changing or turning is needed, the driver is prompted to prohibit lane changing when dangerous target objects exist at the rear, driving risks caused by the fact that the driver observes target objects such as coming vehicles and pedestrians at the rear back in a back-to-back mode during lane changing are avoided, and driving safety is improved.

Drawings

The foregoing features, technical features, advantages and embodiments are further described in the following detailed description of the preferred embodiments, which is to be read in connection with the accompanying drawings.

FIG. 1 is a schematic view of an electric vehicle driving warning system according to the present invention;

FIG. 2 is a schematic diagram of a communication interface protocol according to the present invention;

FIG. 3 is an external schematic view of an alarm module according to the present invention;

FIG. 4 is a flow chart of a method for warning driving of an electric vehicle according to the present invention;

FIG. 5 is a schematic diagram of an integrated millimeter wave radar system according to the present invention;

FIG. 6 is a schematic diagram of a split millimeter wave radar system according to the present invention;

fig. 7 is a schematic view of the installation of the millimeter wave radar system of the electric vehicle.

Reference numerals:

the system comprises a 100-electric vehicle driving warning system, a 110-millimeter wave radar system, a 111-personnel and vehicle state information tracking module, a 112-front-end radio frequency module, a 120-speed measuring module, a 130-steering module, a 140-alarm module and a 150-communication module.

Detailed Description

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following description will be made with reference to the accompanying drawings. It is obvious that the drawings in the following description are only some examples of the invention, and that for a person skilled in the art, other drawings and embodiments can be derived from them without inventive effort.

In an embodiment of the present invention, as shown in fig. 1, an electric vehicle driving warning system 100 includes: the millimeter wave radar system 110 is provided with a personnel and vehicle state information tracking module 111 and a front end radio frequency module 112 which are connected with each other, wherein the personnel and vehicle state information tracking module 111 is used for processing received information and sending out corresponding warnings, and the front end radio frequency module 112 is used for receiving and sending millimeter wave signals towards the rear of the electric vehicle; the speed measuring module 120 is used for measuring the running speed of the electric vehicle in real time; the steering module 130 is used for detecting the steering angle and/or the steering lamp signal of the electric vehicle in real time; the alarm module 140 is used for giving an alarm according to the alarm information sent by the personnel and vehicle state information tracking module 111; the communication module 150 is connected to the personnel and vehicle state information tracking module 111, the speed measuring module 120, the steering module 130 and the alarm module 140, and is configured to send signals detected by the speed measuring module 120 and the steering module 130 to the personnel and vehicle state information tracking module 111 for processing, and send alarm information generated by the personnel and vehicle state information tracking module 111 to the alarm module 140.

The personnel and vehicle state information tracking module 111 comprises a radio frequency parameter adjusting module and a signal processing module, wherein the radio frequency parameter adjusting unit is used for configuring waveform parameters of millimeter wave signals sent by the front-end radio frequency module 112; the signal processing module is configured to process the signals fed back by the front-end radio frequency module 112, the speed measurement module 120, and the steering module 130 to generate alarm information. Specifically, after the personnel and vehicle state information tracking module 111 receives the echo signal reflected by the detected target object, the movement speed of the target object behind the electric vehicle is calculated, the movement track of the target object is tracked, whether dangerous target objects (pedestrians, vehicles and the like which can cause driving safety to the electric vehicle) exist behind the target object is further judged, the target object is classified according to the dangerous stratification level, relevant alarm information is sent to the alarm module 140 to prompt driving in time, and especially when turning/lane changing is needed, if the dangerous stratification is high, even the electric vehicle is decelerated and the driver is warned to prohibit lane changing or turning.

The front-end radio frequency module 112 transmits and receives millimeter wave signals by using an N-transmit-M-receive MIMO radar system. During the driving process of the electric vehicle, the front end rf module 112 continuously transmits electromagnetic wave signals to the rear region and receives multiple paths of target echo signals in the rear region. And after receiving the echo signal, mixing it with the transmitted electromagnetic wave signal, and then performing intermediate frequency. After the intermediate frequency signal is obtained, ADC sampling is further performed on the intermediate frequency signal, and the sampled value is sent to the personnel and vehicle state information tracking module 111 for processing. The ADC sampling module may be selected according to actual required precision, and is not specifically limited herein, for example, two I/Q paths of 16-bit precision sampling values are obtained by sampling.

As shown in fig. 2, the communication module 150 (corresponding to the communication interface module in the figure) may interact data through WiFi, ethernet, CAN, ZigBee, serial ports (RS232, RS485, RS422), and other network protocols. The steering module 130 is disposed on a steering column of the electric vehicle, detects a steering angle and/or a steering signal of the electric vehicle in real time through the hall sensor, and sends the steering angle and/or the steering signal to the millimeter wave radar system 110 through the communication module 150, so as to feed back whether the electric vehicle has a lane change or a turning situation in real time. The speed measuring module 120 is disposed on the electric vehicle wheel, and measures the running speed of the electric vehicle in real time through the speed measuring sensor.

In addition to the alarm module 140 being mounted internally as shown in FIG. 1, in another embodiment, as shown in FIG. 3, the alarm module 140 can also be mounted externally. The communication module sends the heartbeat frequency and the movement information to the external alarm module 140, and the communication module 150 in the external alarm module 140 receives the signal and transmits the signal to the alarm module 140 for alarming. That is, the alarm module 140 is provided with a built-in communication module for communicating with the millimeter wave radar system 110, and a buzzer, a red light, a green light, a yellow light, and the like.

More specifically, the signal processing module comprises: the calculating unit is used for processing ADC sampling data sent by the front-end radio frequency module to obtain the distance between the front-end radio frequency module and a target object, the movement speed of the target object and the angle and speed of the target object relative to the electric vehicle; the comparison unit is connected with the calculation unit and used for comparing the steering angle of the electric vehicle detected by the steering module with a preset angle threshold value and judging whether the electric vehicle needs to be steered or not; the device is used for comparing the calculated distance to the target object, the movement speed of the target object, the angle and the speed of the target object relative to the electric vehicle with preset corresponding threshold values and judging whether the steering condition is met; the judging unit is respectively connected with the comparing unit and the calculating unit and is used for judging whether a dangerous target object exists behind according to the calculated distance between the judging unit and the target object, the movement speed of the target object and the angle and speed of the target object relative to the electric vehicle; comparing the steering angle of the electric vehicle detected by the steering module with a preset angle threshold value, and judging whether the electric vehicle needs to be steered; and the alarm information generating unit is used for generating corresponding alarm information according to the judgment result of the judging unit.

In the calculation unit, for ADC sampling data sent by the front-end radio frequency module, algorithm processing is performed in a distance dimension and a doppler dimension respectively to extract information such as a target radial distance, a radial velocity (a gaussian plane coordinate system is established with the electric vehicle as a center in the calculation process, the target radial distance is a distance from a target object to the electric vehicle, and the radial velocity is a velocity of the target object relative to the electric vehicle), and the like, and the algorithm includes, but is not limited to, fourier transform, maximum likelihood, least square method, and the like. And then, carrying out angle dimension algorithm processing on the data after distance dimension and speed dimension processing to obtain target azimuth information, wherein the algorithm comprises but is not limited to Fourier transform, a maximum likelihood method, a subspace method and the like, so as to obtain the distance to the target object, the movement speed of the target object, and the angle and the speed of the target object relative to the electric vehicle.

In the judging process, the method comprises the following steps: comparing the steering angle of the electric vehicle detected by the steering module with a preset angle threshold value, and judging whether the electric vehicle needs to be steered; when the steering angle is larger than the set threshold value theta₁The intention of turning and changing lanes of the electric vehicle is explained; when the steering angle is smaller than the set threshold value theta₁The intention of the electric vehicle for changing lanes without steering is explained. And then, judging whether the rear part exists or not according to the calculated distance between the electric vehicle and the target object, the movement speed of the target object, the angle and the speed of the target object relative to the electric vehicleAt a dangerous target; if not, further comparing the calculated distance to the target object, the movement speed of the target object, the angle and the speed of the target object relative to the electric vehicle with preset corresponding thresholds, and judging whether the steering condition is met; and generating a warning signal according to the judgment result and sending the warning signal to the alarm module through the communication module.

In judging whether a dangerous target object exists behind according to the calculated distance between the electric vehicle and the target object, the movement speed of the target object and the angle and speed of the target object relative to the electric vehicle, the judging step for one target object comprises the following steps: whether the target object has collision risk with the electric vehicle or not is judged according to the angle of the target object relative to the electric vehicle, whether the target object is a rear vehicle or a side vehicle relative to the electric vehicle or not is judged, and whether the target object collides with the electric vehicle or not is judged under the operation of the angle. If yes, calculating the safe collision avoidance time TTC of the vehicle according to the calculated distance between the vehicle and the target object and the speed of the target object relative to the electric vehicle, wherein the formula is as follows (1):

TTC＝ΔS/ΔV (1)

wherein, Δ S is the distance between the electric vehicle and the target object, and Δ V is the speed of the target object relative to the electric vehicle;

calculating the vehicle distance early warning time HWM according to the calculated distance between the vehicle distance and the target object and the movement speed of the target object, wherein the formula is (2):

HWM＝ΔS/V₁ (2)

wherein, V₁The movement speed of the target object;

judging whether the calculated vehicle safe collision avoidance time TTC and the vehicle distance early warning time HWM are not smaller than a preset vehicle safe collision avoidance time threshold and a preset vehicle distance early warning threshold at the same time; the target object is determined not to be a dangerous target object. And if the vehicle safe collision avoidance time TTC is smaller than a preset vehicle safe collision avoidance time threshold or the vehicle distance early warning time HWM is smaller than a vehicle distance early warning threshold, judging that the target is a dangerous target and having collision risk.

Aiming at the calculation result, in the generated alarm information, when it is judged that no dangerous target exists behind the alarm information, the alarm signal is sent to the alarm module 140 for green light prompt; when the situation that the electric vehicle does not need to turn but a dangerous target object exists behind the electric vehicle is judged, the warning signal is sent to the alarm module 140 to prompt the driver with a yellow light; when the electric vehicle is judged to need to turn and a dangerous target object exists behind the electric vehicle, the warning signal is sent to the alarm module 140 to prompt the red light.

In other embodiments, the alarm information may be further categorized according to alarm levels in different states, as shown in Table 1:

table 1: classification results of alarm levels under different conditions

Status of state	Steering state	Tracking target hazard level	Grade of alarm lamp
				Q1	Is provided with	Has high risk due to the existence of the target	Red light
Q2	Is provided with	Has target object and low risk	Yellow lamp (flicker frequency is high)
				Q3	Is free of	With a target object	Yellow lamp (flicker frequency low)
Q4	Is free of	Without target	Green lamp
				Q5	Is provided with	Without target	Green lamp

The state Q1 indicates that the electric vehicle has a steering action (turning or lane changing) and detects that a rear target object has a high risk (dangerous target object exists) for the current lane changing, at this time, an alarm signal should be sent to the alarm module, and the alarm module gives an alarm with a red light to warn that the electric vehicle is prohibited from turning or changing lanes.

The state Q2 indicates that the electric vehicle has a steering action and detects that there is a target object behind, but the distance, relative speed and position of the target object do not pose a danger to a turn or a lane change, and at this time, a high-frequency yellow light is turned on to indicate that there is a pedestrian or a vehicle behind and the lane change or the turn can be safely performed.

The state Q3 indicates that the electric vehicle is not steering, but there is a detected object in the rear, at which time a low frequency yellow light is lit, indicating that no pedestrian is detected in the rear or that the vehicle can continue to drive safely.

The state Q4 indicates that the electric vehicle has no intent to turn and no associated pedestrian or vehicle is detected at the rear, and the green light is on, indicating that no pedestrian is detected at the rear or that the vehicle can continue to drive safely.

The state Q5 indicates that when the electric vehicle is turning, no pedestrian or vehicle is detected behind the electric vehicle, and the green light is turned on, indicating that no pedestrian is detected behind the electric vehicle or that the vehicle can safely change lanes and turn.

Correspondingly, the invention also provides an electric vehicle driving warning method applied to the electric vehicle driving warning system, as shown in fig. 4, the electric vehicle driving warning method comprises the following steps:

s10, controlling the front-end radio frequency module to emit millimeter wave signals towards the rear of the electric vehicle and receiving the returned millimeter wave signals;

s20 receiving signals obtained by mixing the received millimeter wave signals and the transmitted millimeter wave signals and then performing ADC (analog to digital converter) sampling by the front-end radio frequency module;

s30, receiving the running speed of the electric vehicle measured by the speed measuring module in real time through the communication module;

s40, receiving the steering angle and/or the steering lamp signal of the electric vehicle detected by the steering module in real time through the communication module;

s50 processes the received information and sends the warning information to the warning module for warning through the communication module.

Specifically, in step S10, the rf parameter adjustment module in the personnel and vehicle status information tracking module sets the millimeter wave waveform parameters to be transmitted and sends the millimeter wave waveform parameters to the front-end rf module, and the front-end rf module transmits the electromagnetic waves to the rear area of the electric vehicle in an MIMO manner according to the set waveform. After receiving the echo signal, it is mixed with the transmitted electromagnetic wave signal, followed by an intermediate frequency in step S20. After the intermediate frequency signal is obtained, ADC sampling is further carried out on the intermediate frequency signal, and the sampling value is sent to a personnel and vehicle state information tracking module for processing. The ADC sampling module may be selected according to actual required precision, and is not specifically limited herein, for example, two I/Q paths of 16-bit precision sampling values are obtained by sampling.

In step S50, for the ADC sample data sent by the front-end rf module, algorithm processing is performed in the distance dimension and the doppler dimension to extract information such as a target radial distance (a gaussian plane coordinate system is established with the electric vehicle as a center in the calculation process), a radial velocity (a radial velocity is a distance from the target object to the electric vehicle, and a radial velocity is a velocity of the target object relative to the electric vehicle), and the like, where the algorithm includes, but is not limited to, fourier transform, maximum likelihood, least square method, and the like. And then, carrying out angle dimension algorithm processing on the data after distance dimension and speed dimension processing to obtain target azimuth information, wherein the algorithm comprises but is not limited to Fourier transform, a maximum likelihood method, a subspace method and the like, so as to obtain the distance to the target object, the movement speed of the target object, and the angle and the speed of the target object relative to the electric vehicle.

In the judging process, the method comprises the following steps: comparing the steering angle of the electric vehicle detected by the steering module with a preset angle threshold value, and judging whether the electric vehicle needs to be steered; when the steering angle is larger than the set threshold value theta₁The intention of turning and changing lanes of the electric vehicle is explained; when the steering angle is smaller than the set threshold value theta₁The intention of the electric vehicle for changing lanes without steering is explained. Then, judging whether a dangerous target object exists behind according to the calculated distance between the electric vehicle and the target object, the movement speed of the target object and the angle and speed of the target object relative to the electric vehicle; if not, further comparing the calculated distance to the target object, the movement speed of the target object, the angle and the speed of the target object relative to the electric vehicle with preset corresponding thresholds, and judging whether the steering condition is met; and generating a warning signal according to the judgment result and sending the warning signal to the alarm module through the communication module.

In judging whether a dangerous target object exists behind according to the calculated distance between the electric vehicle and the target object, the movement speed of the target object and the angle and speed of the target object relative to the electric vehicle, the judging step for one target object comprises the following steps: whether the target object has collision risk with the electric vehicle or not is judged according to the angle of the target object relative to the electric vehicle, whether the target object is a rear vehicle or a side vehicle relative to the electric vehicle or not is judged, and whether the target object collides with the electric vehicle or not is judged under the operation of the angle. If so, calculating the safe collision avoidance time TTC of the vehicle according to the calculated distance between the vehicle and the target object and the speed of the target object relative to the electric vehicle, as shown in the formula (1); calculating the vehicle distance early warning time HWM according to the calculated distance between the vehicle distance and the target object and the movement speed of the target object, wherein the formula is (2); judging whether the calculated vehicle safe collision avoidance time TTC and the vehicle distance early warning time HWM are not smaller than a preset vehicle safe collision avoidance time threshold and a preset vehicle distance early warning threshold at the same time; the target object is determined not to be a dangerous target object. And if the vehicle safe collision avoidance time TTC is smaller than a preset vehicle safe collision avoidance time threshold or the vehicle distance early warning time HWM is smaller than a vehicle distance early warning threshold, judging that the target is a dangerous target and having collision risk.

In the process, whether a dangerous target object exists behind is judged according to the calculated distance from the target object, the movement speed of the target object and the angle and speed of the target object relative to the electric vehicle; specifically, the relative speed between the electric vehicle and the target object, the direction and the distance of the target object relative to the electric vehicle and the like are integrated, whether the target object can cause danger to the electric vehicle is judged, and a dangerous target object is formed. Here, the calculated vehicle safe collision avoidance time TTC is used to describe the time at which the current electric vehicle collides with a following vehicle or other moving object at a relative speed. And the distance warning time HWM is used as another evaluation index and gives an alarm when the distance is too close. For example: when the distance between the front vehicle and the rear vehicle is 20 meters, the speed of the rear vehicle (target object) is 60Km/h, the speed of the front vehicle (electric vehicle) is 80Km/h, the calculated vehicle distance early warning time HWM is 1.2s, the potential rear-end collision time TTC of the rear vehicle is 3.6s, and the time is less than the preset time threshold value 5s, and early warning is sent out. If the speeds of the front and rear vehicles are 60Km/h, although the time displayed by the inter-vehicle distance warning time HWM is 1.2s, the two vehicles are close to each other, but the speeds are the same, and the rear-end collision cannot occur.

In addition, when the electric vehicle is judged to need to turn, the calculated distance from the target object, the movement speed of the target object, the angle and the speed of the target object relative to the electric vehicle are further compared with preset corresponding threshold values, and whether a turning condition is met is judged; when the tracked target object information is smaller than the lane change threshold value, the fact that the target object is at the rear and can cause danger to the steering of the electric vehicle is indicated, and at the moment, the warning signal is sent to the alarm module to prompt the red light. In addition, in the driving process, when the dangerous target does not exist behind the vehicle, the warning signal is sent to the alarm module to carry out green light prompt; when the situation that the electric vehicle does not need to turn and a dangerous target object exists behind the electric vehicle is judged, the warning signal is sent to the alarm module to prompt the driver with a yellow light.

In other embodiments, the flashing frequency of the warning lamp can be controlled according to the judgment result, for example, when the electric vehicle is judged to need to turn, and a target object is behind but the danger degree is low, a warning signal is sent to the alarm module to prompt a yellow light, and the electric vehicle is controlled to flash at a preset high frequency; when the electric vehicle does not need to turn and a target object is arranged behind the electric vehicle, the warning signal is sent to the alarm module to prompt the driver to turn to the yellow light, and the electric vehicle is controlled to flicker at a preset low frequency.

The invention also provides a millimeter wave radar system which comprises a single-chip transmitting antenna array, a receiving antenna array, a front-end radio frequency, a signal processor, a memory and a computer program which is stored in the memory and can be run on the processor, wherein the steps of the electric vehicle driving warning method are realized when the computer program is executed.

In practical applications, different embodiments of the front-end rf module (single-chip N-transceiver and M-transceiver antenna array), the rf parameter tuning unit (frequency modulation module), and the signal processing module (processor) may be an integrated millimeter-wave radar system or a separated millimeter-wave radar system. The emitted millimeter waves include but are not limited to 24G, 60G or 77G, and N chirp s are scanned towards the back of the electric vehicle once every period T by adopting a continuous frequency modulation method.

In an example of integrating the integrated millimeter wave radar system, as shown in fig. 5, there are integrated: the single-chip transmitting antenna array, the single-chip receiving antenna array and the single-chip front-end radio frequency RF and DSP signal processor are characterized in that the DSP signal processor controls the front-end radio frequency RF to transmit 60GHz or 77GHz millimeter wave signals to a detected space behind the electric vehicle through the transmitting antenna array (corresponding to n transmitting antennas in the figure), the receiving antenna array (corresponding to m receiving antennas in the figure) receives echo signals after the signals are reflected by pedestrians, animals, vehicles and the like in the detected area, the front-end radio frequency RF caches the processed echo data in an RF internal RAM1, the RAM echo data in the RF is moved to an internal RAM2 of the signal processor in a ping-pong mode through EDMA driving and stored, and the SPT signal processor analyzes and detects the speed, the distance azimuth angle and the movement information of a target object through the echo signals, so that the real-time tracking of multiple targets is realized.

In an example of the split millimeter wave radar system, as shown in fig. 6, it includes: the system comprises a transceiving antenna array, a front-end radio frequency RF chip and a DSP signal processor, wherein the front-end radio frequency RF transmits 60GHz or 77GHz millimeter waves, ADC sampling is carried out after echo signals reflected by pedestrians, animals and vehicles in a detected area are received, sampling data are conveyed to an RAM of the DSP signal processor through an EDMA drive, SPT signals are stored, speed, distance azimuth angles and movement information of a target object are analyzed and detected through the echo signals, and real-time tracking of multiple targets is achieved.

The invention also provides an electric vehicle provided with at least one millimeter wave radar system. When a plurality of millimeter wave radar systems are configured, the millimeter wave radar systems are in communication connection with one another, and when millimeter wave radar system data from different installation positions are received, target point multivariate fusion is performed on the data of the target object, so that the accuracy of target object information is improved, and the efficiency and accuracy of information processing are improved.

FIG. 7 is a schematic diagram showing the installation of millimeter wave radar systems for different types of electric vehicles, wherein, for two-wheeled electric vehicles, a millimeter wave radar system is installed behind the two-wheeled electric vehicles; for three-wheeled electric vehicles and four-wheeled electric vehicles, a millimeter wave radar system can be respectively arranged on the left side and the right side to sweep blind areas in a detection area. When the millimeter wave radar systems are installed on the left side and the right side, the information of the target objects detected by the millimeter wave radar systems is fused, so that the confidence of target tracking is improved. Of course, in order to save cost, a millimeter wave radar system can be installed behind the three-wheeled electric vehicle and the four-wheeled electric vehicle.

It should be noted that the above embodiments can be freely combined as necessary. The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for persons skilled in the art, numerous modifications and adaptations can be made without departing from the principle of the present invention, and such modifications and adaptations should be considered as within the scope of the present invention.