1. A vehicle-mounted silent horn system is characterized in that: the device comprises a detection module, a control module, a prompt module, a DSP power supply conversion circuit and a communication interface;

the detection module is used for detecting vehicles and pedestrians in front of the vehicles and sending the detected results to the control module;

the control module is used for receiving the information of the detection module, processing and analyzing the information and controlling the prompt module to prompt according to the analysis and processing results;

the prompting module is used for receiving a control command of the control module, prompting a vehicle coming from the rear of a front vehicle and prompting pedestrians in front of and around the vehicle body to pay attention to the vehicle coming;

the DSP power supply conversion circuit is connected with the vehicle-mounted power supply system and converts a vehicle-mounted current source into direct current for the control module to use;

and the communication interface is used for programming a control module of the device by a computer, and communicating and transmitting data between the device and other vehicle-mounted equipment and the vehicle-mounted computer.

2. The vehicular silent horn system according to claim 1, wherein: the control module comprises a DSP-based high-speed data processor module and an MCU (microprogrammed control unit), the DSP-based high-speed data processor module is connected with the MCU through an SPI (serial peripheral interface) synchronous serial circuit, the MCU receives data information from the DSP-based high-speed data processor module and a control command of the prompt module, and the prompt module is controlled to prompt; and the peripheral circuit arranged on the DSP-based high-speed data processor module comprises a DSP reset circuit, a DSP clock circuit, a JTAG interface circuit and a DSP off-chip memory expansion circuit, and the DSP-based high-speed data processor module is provided with a CAN communication interface.

3. The vehicular silent horn system according to claim 2, wherein: the DSP-based high-speed data processor module adopts dual power supplies for power supply, the core voltage is 1.8V, and the I/O interface and flash programming voltage is 3.3V; the DSP power supply conversion circuit is a two-way output low-voltage drop voltage stabilizer.

4. The vehicular silent horn system according to claim 2, wherein: the detection module comprises a vehicle-mounted radar sensor, a radar receiver, a vehicle-mounted speed measurement detector and a vehicle-mounted image sensor, wherein the vehicle-mounted radar sensor, the vehicle-mounted speed measurement detector and the vehicle-mounted image sensor are all arranged at the front end of the vehicle body;

the vehicle-mounted radar sensor is a microwave radar, a radar ranging and signal acquisition circuit system is arranged in the vehicle-mounted radar sensor, and is connected with the DSP-based high-speed data processor module and the DSP-based high-speed data processor module through a preamplification circuit, and is used for detecting the distance and speed of a front vehicle and transmitting and receiving radar wave signals to the front vehicle;

the vehicle-mounted speed measurement detector is a Hall sensor and is used for detecting the driving speed, and the Hall sensor is connected with the DSP-based high-speed data processor module through a signal conditioning circuit;

the vehicle-mounted image sensor is used for acquiring figure images within a safe distance in front of a vehicle, judging whether the person is a pedestrian or not through image comparison and identification, and consists of a high-speed data processor module based on a DSP (digital signal processor), a register and a video sensor, wherein the video sensor is connected with a video decoder, the data acquired by the video sensor is decrypted through the video decoder, and the high-speed data processor module based on the DSP and the video decoder are connected through an I²C bus connection, DSP-based high-speed data processor module through I²C, reading and writing related data in a video decoder register in a bus serial communication mode;

the radar receiver is arranged on the rear side of the vehicle body and used for receiving radar wave signals sent by a rear vehicle.

5. The vehicular silent horn system according to claim 2, wherein: the MCU micro control unit is a single chip microcomputer, the single chip microcomputer is connected with the prompting module through an output port of the single chip microcomputer, and the prompting mode of the prompting module is controlled.

6. The vehicular silent horn system according to claim 5, wherein: the prompting module comprises an in-vehicle prompting horn, an out-vehicle prompting horn and a vehicle-mounted horn key;

the signal acquisition input end of the vehicle-mounted horn key is connected with a P4.4 pin of the single chip microcomputer, and the switch-on of the switch SW1 is controlled by pressing the vehicle-mounted horn key by a driver;

an in-vehicle horn alarm circuit is arranged on the in-vehicle prompting horn, the system alarm circuit adopts a buzzer alarm type, and the driver presses the vehicle-mounted horn button to give a long-tone alarm;

the outside-vehicle horn is provided with an outside-vehicle horn alarm circuit, and the outside-vehicle horn is driven to give out prompt sound by a driver pressing a vehicle-mounted horn button.

7. A vehicle-mounted silent horn system as claimed in claim 1 or 3, wherein: the communication interface is a CAN communication bus.

Background

With the social and economic development and the improvement of the living standard of people, automobiles begin to enter every family and become one of the main modes of people going out;

however, the fuel automobile can generate tail gas pollution, noise pollution and the like in the driving process, wherein the noise pollution has the most direct influence on the living environment of people, and the noise pollution mainly comprises the mechanical structure noise of the automobile body, the engine noise, the tire friction noise, the horn noise and the like in the driving process;

among these noises, horn noise is particularly serious, and many places are prohibited to whistle in a part of areas and road sections in order to reduce horn noise, but this method is not a permanent cure, and may affect driving safety to some extent.

Disclosure of Invention

Aiming at the existing problems, the invention aims to provide a vehicle-mounted silent horn system, which plays a role of prompting vehicles and pedestrians while reducing horn noise as much as possible, reduces noise pollution of the vehicle-mounted horn to the maximum extent, and has the characteristics of high integration level, multi-sensor fusion, comprehensive detection objects and strong data processing capability.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a vehicle-mounted silent horn system comprises a detection module, a control module, a prompt module, a DSP power supply conversion circuit and a communication interface;

the detection module is used for detecting vehicles and pedestrians in front of the vehicles and sending the detected results to the control module;

the control module is used for receiving the information of the detection module, processing and analyzing the information and controlling the prompt module to prompt according to the analysis and processing results;

the prompting module is used for receiving a control command of the control module, prompting a vehicle coming from the rear of a front vehicle and prompting pedestrians in front of and around the vehicle body to pay attention to the vehicle coming;

the DSP power supply conversion circuit is connected with the vehicle-mounted power supply system and converts a vehicle-mounted current source into direct current for the control module to use;

and the communication interface is used for programming a control module of the device by a computer, and communicating and transmitting data between the device and other vehicle-mounted equipment and the vehicle-mounted computer.

Preferably, the control module comprises a DSP-based high-speed data processor module and an MCU (microprogrammed control unit), the DSP-based high-speed data processor module is connected with the MCU through an SPI (serial peripheral interface) synchronous serial circuit, the MCU receives data information from the DSP-based high-speed data processor module and a control command of the prompt module, and the prompt module is controlled to prompt; and the peripheral circuit arranged on the DSP-based high-speed data processor module comprises a DSP reset circuit, a DSP clock circuit, a JTAG interface circuit and a DSP off-chip memory expansion circuit, and the DSP-based high-speed data processor module is provided with a CAN communication interface.

Preferably, the DSP-based high-speed data processor module is powered by double power supplies, the core voltage is 1.8V, and the I/O interface and flash programming voltage is 3.3V; the DSP power supply conversion circuit is a two-way output low-voltage drop voltage stabilizer.

Preferably, the detection module comprises a vehicle-mounted radar sensor, a radar receiver, a vehicle-mounted speed measurement detector and a vehicle-mounted image sensor, and the vehicle-mounted radar sensor, the vehicle-mounted speed measurement detector and the vehicle-mounted image sensor are all arranged at the front end of the vehicle body;

the vehicle-mounted radar sensor is a microwave radar, a radar ranging and signal acquisition circuit system is arranged in the vehicle-mounted radar sensor, and is connected with the DSP-based high-speed data processor module and the DSP-based high-speed data processor module through a preamplification circuit, and is used for detecting the distance and speed of a front vehicle and transmitting and receiving radar wave signals to the front vehicle;

the vehicle-mounted speed measurement detector is a Hall sensor and is used for detecting the driving speed, and the Hall sensor is connected with the DSP-based high-speed data processor module through a signal conditioning circuit;

the vehicle-mounted image sensor is used for acquiring images of people within a safe distance in front of the vehicle and comparing the imagesAnd identifying and judging whether the pedestrian is the pedestrian, wherein the pedestrian is composed of a high-speed data processor module based on DSP, a register and a video sensor, the video sensor is connected with a video decoder, the data acquired by the video sensor is decrypted by the video decoder, and the high-speed data processor module based on DSP and the video decoder are connected through I²C bus connection, DSP-based high-speed data processor module through I²C, reading and writing related data in a video decoder register in a bus serial communication mode;

the radar receiver is arranged on the rear side of the vehicle body and used for receiving radar wave signals sent by a rear vehicle.

Preferably, the MCU micro control unit is a single chip microcomputer, and the single chip microcomputer is connected with the prompting module through an output port of the single chip microcomputer to control a prompting mode of the prompting module.

Preferably, the prompt module comprises an in-vehicle prompt horn, an out-vehicle prompt horn and a vehicle-mounted horn key;

the signal acquisition input end of the vehicle-mounted horn key is connected with a P4.4 pin of the single chip microcomputer, and the switch-on of the switch SW1 is controlled by pressing the vehicle-mounted horn key by a driver;

an in-vehicle horn alarm circuit is arranged on the in-vehicle prompting horn, the system alarm circuit adopts a buzzer alarm type, and the driver presses the vehicle-mounted horn button to give a long-tone alarm;

the outside-vehicle horn is provided with an outside-vehicle horn alarm circuit, and the outside-vehicle horn is driven to give out prompt sound by a driver pressing a vehicle-mounted horn button.

Preferably, the communication interface is a CAN communication bus.

The invention has the beneficial effects that: the invention discloses a vehicle-mounted silent horn system, which is improved in that:

(1) on the one hand, the vehicle-mounted silent horn system can effectively prompt a vehicle ahead to ensure driving safety and effectively reduce the using frequency of a horn outside the vehicle on the premise of not influencing safe driving by the device, thereby reducing the horn noise generated in the driving process of the vehicle, providing better living and working environments for people and improving the happiness index of the life of the people;

(2) on the other hand, with the application and the rise of the concept of intelligent interconnection in various industries, the intelligent automobile is developed vigorously, and the application of the device is also one embodiment of more intellectualization and humanization of the automobile; meanwhile, the device has the advantages of high integration level, multi-sensor fusion, comprehensive detection objects and strong data processing capability.

Drawings

Fig. 1 is a control configuration diagram of the vehicular silent horn device of the present invention.

Fig. 2 is a flowchart showing the operation of the vehicular silent horn device of the present invention.

FIG. 3 is a diagram of a DSP power conversion circuit according to the present invention.

FIG. 4 is a circuit diagram of a DSP-based high-speed data processor module according to the present invention.

FIG. 5 is a diagram of a DSP reset circuit of the DSP-based high-speed data processor module of the present invention.

FIG. 6 is a DSP clock circuit diagram of the DSP-based high-speed data processor module of the present invention.

FIG. 7 is a circuit diagram of the JTAG interface of the DSP-based high-speed data processor module of the present invention.

FIG. 8 is a circuit diagram of the DSP off-chip memory expansion circuit of the DSP-based high-speed data processor module according to the present invention.

FIG. 9 is a diagram of an SPI synchronous serial circuit between a DSP and an MCU according to the present invention.

FIG. 10 is a diagram of a CAN communication circuit of the DSP according to the present invention.

FIG. 11 is a circuit diagram of a 10-3C type microwave radar and acquisition processing circuit according to the present invention.

Fig. 12 is a circuit diagram of a video capture circuit of the present invention.

FIG. 13 shows the present invention I²C, a circuit diagram.

FIG. 14 is a circuit diagram of the minimum operating system of the MCU of the present invention.

FIG. 15 is a communication circuit diagram of an RS-232 serial interface according to the present invention.

FIG. 16 is a circuit diagram of a vehicle speed signal acquisition according to the present invention.

FIG. 17 is a circuit diagram of the key of the vehicle horn of the present invention.

Fig. 18 is a circuit diagram of the warning circuit of the prompt horn in the vehicle.

Fig. 19 is a circuit diagram of an out-vehicle prompting horn alarm circuit of the invention.

Detailed Description

In order to make those skilled in the art better understand the technical solution of the present invention, the following further describes the technical solution of the present invention with reference to the drawings and the embodiments.

Referring to fig. 1-19, a vehicle-mounted silent horn system comprises a DSP power conversion circuit, a control module, a detection module, a prompt module and a communication interface;

the detection module is used for detecting vehicles and pedestrians in front of the vehicles and sending the detected results to the control module for analysis and processing;

the control module is used for receiving the information of the detection module, processing and analyzing the information, and controlling the prompt module to prompt according to the analysis and processing result, so as to remind the coming vehicle behind the front vehicle and remind the pedestrians in front of and around the vehicle body to pay attention to the coming vehicle;

the prompting module is used for receiving the control command of the control module and prompting pedestrians and vehicles;

the DSP power supply conversion circuit is connected with the vehicle-mounted power supply system and converts a vehicle-mounted current source into direct current for the control module to use;

and the communication interface is used for compiling a program for the control module of the device by the computer, and for communication and data transmission of interconnection between the device and other vehicle-mounted equipment and the vehicle-mounted computer, so that data sharing between the system and the vehicle-mounted control computer is realized, interconnection between the vehicle-mounted equipment and the Internet of things is realized, and equipment expansion is facilitated.

Preferably, the control module include high speed data processor module and MCU little the control unit based on DSP, be connected through the synchronous serial circuit of SPI between high speed data processor module and the MCU little the control unit based on DSP, specifically be with four pins of DSP's SPI module: SPISCLK, SPIMISO, SPIMOSI and SPISS are respectively connected with SCLK/P1.7, MISO/P1.6, MOSI/P1.5 and SS/P1.4 ports of MCU (STC12C5A60S2), namely when in use, after the DSP analyzes and processes the radar detection signal and the video signal, the DSP is respectively connected with SCLK/P1.7, MISO/P1.6, MOSI/P1.5 and SS/P1.4 ports of MCU (STC12C5A60S2) through SPISCLK, SPIMISO, SPIMOSI and SPISS four pins of the DSP, relevant processing information is sent to the MCU, the MCU micro-control unit receives data information from the DSP-based high-speed data processor module and a control command of the prompting module, controls the prompting module to operate and prompt; the high-speed data processor module based on the DSP selects a TMS320F2812 microprocessor, a DSP reset circuit, a DSP clock circuit, a JTAG interface circuit and a DSP off-chip memory expansion circuit are arranged on a peripheral circuit of the high-speed data processor module based on the DSP, the DSP reset circuit is used for manual reset, when a switch is pressed, the DSP is forced to reset, the DSP clock circuit provides clock signals for the operation of the DSP and all peripheral equipment, a JTAG (Joint Test Action group) interface circuit scanning logic circuit is mainly used for online simulation debugging and is also a unique channel for loading data and codes in the debugging process, an emulator CAN be connected with a target system through a JTAG interface to carry out system debugging, the DSP expansion memory is used for increasing the data storage amount, and a CAN communication interface is arranged on the high-speed data processor module based on the DSP to realize the function of the Internet of things, the SN65HVD232 is an interface between a driving CAN controller and a physical bus and provides differential sending and receiving functions for the bus; the vehicle-mounted silent horn system is an intelligent vehicle-mounted device running on a vehicle, needs to work for a long time, has higher requirements on the performance of a singlechip and more control strategies to be realized, therefore, the system adopts the STC12C5A60S2 single chip microcomputer as the main control chip of the system, namely, an STC12C5A60S2 single chip microcomputer is adopted as an MCU micro control unit, the STC12C5A60S2 single chip microcomputer is connected with a prompt module through an output port of the single chip microcomputer to control the prompt mode of the prompt module, and the STC12C5A60S2 singlechip is connected with the computer through an RS-232 serial communication circuit, wherein the level conversion chip of the RS-232 serial communication circuit is MAX232, the level conversion chip of the serial communication circuit adopts MAX232 produced by Meixin company, the function is to convert TTL level output by the single chip microcomputer into RS-232 level which can be received by the PC or convert RS-232 level output by the PC into TTL level which can be received by the single chip microcomputer; MAX232 adopts a +5V single power supply to supply power, and the level interchange of TTL and RS-232 can be realized only by a plurality of external capacitors; t1in and R1out of a typical MAX232 level shift circuit are connected to P3.1 and P3.0 pins of a single chip, respectively, so that level shift between the single chip and a PC can be realized, and data communication between the single chip and the PC is finally completed.

Preferably, the detection module is used for detecting vehicles and pedestrians in front of the vehicle, and sending the detected results to the control module for analysis and processing, and comprises a vehicle-mounted radar sensor, a radar receiver, a vehicle-mounted speed measurement detector and a vehicle-mounted image sensor, wherein the vehicle-mounted radar sensor, the vehicle-mounted speed measurement detector and the vehicle-mounted image sensor are all arranged at the front end of the vehicle body; the radar receiver is arranged at the tail end of the vehicle body;

radar ranging and acquisition:

the vehicle-mounted radar sensor (radar ranging and signal acquisition circuit system) selects a 10-3C type microwave radar as the vehicle-mounted ranging sensor, and the 10-3C type microwave radar can meet the special requirements of the system in ranging and is key to detect a target under any weather condition and the precision is hardly influenced; the 10-3C type microwave radar has three leads which are respectively an earth wire, a power wire and a mixing signal output wire, a working power supply is a DC +8V direct-current power supply, the power consumption is about 80 milliamperes, a microwave signal source adopts an all-solid-state device, a horn-shaped antenna of an aluminum alloy cavity receives and transmits, and a mixing tube receives and mixes reflected echo signals and transmitted wave signals; connecting the output echo difference frequency signal to an ADCZNB0 pin of a TMS320F2812 microprocessor; because the difference frequency signal changes between 1mV and 100mV along with the distance of a target, and the echo signal is relatively weak and is easily interfered by an external signal, a preamplification circuit is required to be connected between a 10-3C type microwave radar and a TMS320F2812 microprocessor to amplify the difference frequency signal to between 30mV and 3V; the TLC2652 is a cheap high-precision chopper-stabilized operational amplifier and has excellent characteristics in the aspects of offset voltage suppression, low-frequency noise, drift, gain and the like, so that the TLC2652 is selected as a pre-amplification circuit and used for detecting the distance and the speed of a front vehicle and transmitting and receiving radar wave signals to the front vehicle, namely, when the TLC2652 is used, a power supply (3 pins) of a 10-3C type microwave radar is connected with a DC +8V direct-current power supply through a wire; the ground wire (pin 1) is grounded, a mixing signal output wire (pin 2) is connected with a signal input end (pin 1) of a pre-amplifier TLC2652, signals are output through an output pin (pin 2) after being processed by the pre-amplifier and are sent to an input pin ADNENB0 pin of the DSP, and relevant data are processed in the DSP;

acquiring an automobile speed signal:

the speed of the automobile is obtained by a vehicle-mounted speed measuring detector, real-time and accurate speed signals are provided for a system, and the Hall type speed sensor has the characteristics of high sensitivity to a magnetic field, good linearity, strong anti-electromagnetic interference capability, stable output signals and the like, so that the Hall type speed sensor is widely applied to the automobile; the AH3144L Hall sensor is a wide-temperature, high-sensitivity single-polarity switch type Hall effect vehicle speed sensor, the working temperature range can reach-40 ℃ to 150 ℃, and the working voltage is as follows: 4.5V-24V, adopt TO-92 UA's encapsulation form, by power cord VCC, ground wire GND and signal output line OUT, 3 pin wires total respectively, hall formula speed sensor installs in the derailleur shell usually, with speed of a motor vehicle odometer initiative axle connection, by the flexible axle drive driving axle of speedmeter of derailleur output shaft, again by the flexible axle drive driving axle. When the automobile runs, the sensor outputs an electric pulse signal every time the output shaft of the speed changer rotates for one circle, and the output electric pulse signal is transmitted to the main control unit, so that the current speed of the automobile can be calculated; in order to reduce electromagnetic interference and improve signal accuracy, a signal conditioning circuit is required to be added between the Hall sensor and the single chip microcomputer, and the signal conditioning circuit is mainly used for carrying out frequency modulation and amplitude modulation processing on sinusoidal signals generated by the Hall sensor to convert the sinusoidal signals into rectangular pulse signals; wherein: the OUT terminal (pin 1) of the AH3144L is used as a signal output terminal, and the vehicle speed detection signal is sent to a conditioning circuit composed of 6N137 and 7414, and the signal is preprocessed, and the processed signal is sent to P1.2 (pin 3) of the MUC.

Image acquisition and processing circuit:

vehicle-mounted image sensorThe system comprises a TMS320F2812 microprocessor, an SAA7111 video decoder and a video sensor, wherein the video sensor is connected with the SAA7111 video decoder, the data acquired by the video sensor is decrypted by the SAA7111 video decoder, and the TMS320F2812 microprocessor and the SAA7111 video decoder are connected through an I²C bus connection, TMS320F2812 through I²C, reading and writing related data in the SAA7111 register in a serial communication mode of a bus; wherein: the VIDEO sensor (VIDEO) sends out a detection signal through an age (pin 4), and the detection signal is sent to the SAA7111 VIDEO decoder after being conditioned, so that the SAA7111 VIDEO decoder can convert an input VIDEO image signal into a digital signal, and communication data interaction of I2C is realized through connection of an SCL (pin 64)/SDA (pin 63) of the SAA7111 and an SCL/SDA pin of the TMS320F 2812.

The radar receiver is arranged on the rear side of the vehicle body and used for receiving radar wave signals sent by a rear vehicle.

Preferably, the DSP power conversion circuit is connected with a vehicle-mounted power supply system, and converts a vehicle-mounted current source into 5V direct current for a control module to use, wherein the TMS320F2812 microprocessor adopts dual power supplies for power supply, the core voltage is 1.8V, the I/O interface and the flash programming voltage are 3.3V, the system selects TPS73HD318 as a power conversion chip of the DSP-based high-speed data processor module, and the 3.3VD digital voltage, the 3.3VA analog voltage and the 1.8VD digital voltage required by the TMS320F2812 microprocessor can be obtained by inputting DC +5V voltage to the TPS73HD 318; wherein: the power supply output 1.8VD is connected with a VDD/VDD1 pin of the DSP, and a 1.8V digital signal power supply is provided for the DSP core; the digital power output 3.3VD is the VDDIO/VDD3VFL pin of DSP to provide 3.3V voltage for flash programming, the analog power output 3.3VA is connected with the VDDA1/VDDIO/VDDA2 pin of DSP to provide power for the analog signal port of DSP.

Preferably, the prompt module comprises an in-vehicle prompt horn, an out-vehicle prompt horn and a vehicle-mounted horn key; the signal acquisition input end of the vehicle-mounted horn key is connected with a P4.4(29 pin) pin of the STC12C5A60S2 singlechip, when a driver presses the vehicle-mounted horn key, the switch SW1 is switched on, the P4.4 pin of the STC12C5A60S2 singlechip is changed into low level to be effective, the vehicle-mounted radar is controlled to send a vehicle speed signal at the moment, when the driver releases the horn key, the switch SW1 is switched off, and the P4.4 pin of the STC12C5A60S2 singlechip is changed into high level to be ineffective;

an in-vehicle horn alarm circuit is arranged on the in-vehicle prompting horn, the system alarm circuit adopts a buzzer alarm type, the buzzer alarm circuit mainly comprises a buzzer, a pull-up resistor and a PNP type triode, the pull-up resistor is used for limiting base current, the triode plays a role in current amplification, when a rear vehicle presses a horn button, the vehicle-mounted radar receives a radar signal sent by the rear vehicle, and if the distance between the two vehicles is greater than the minimum driving safety distance, the buzzer is prompted not to sound; if the distance between the two vehicles is less than the minimum driving safety distance, a buzzer is prompted to give an alarm in a long-time sound mode; and a control signal is sent out through a P2.7(28 pin) port of the singlechip, and the prompt horn in the vehicle is connected.

The automobile external horn prompting circuit is arranged on the automobile external horn and is realized by adopting a high-power horn, the external horn prompting circuit is mainly used for prompting pedestrians, when a monitoring system detects that pedestrians exist in a safety area in front of an automobile, a driver presses a horn button to drive the automobile external horn to send a prompting sound, the automobile external horn driving circuit drives a relay through a single chip microcomputer, a normally open contact of the relay is closed, and the high-power horn is controlled to be powered on to send the prompting sound; a control signal is sent through a P2.7(27 pin) port of the single chip microcomputer, a coil of a relay outside the vehicle is switched on, the relay is normally opened and electrically contacted and closed, and a high-power prompting horn outside the vehicle is driven.

Preferably, the communication interface is a CAN communication bus.

The working principle of the invention is as follows:

(1) when a driver in the vehicle presses down the vehicle-mounted horn key, a key signal is sent into the DSP controller from the MCU through the I/O-SPI serial port;

(2) the DSP receives the key signal and simultaneously controls the vehicle-mounted radar detector, the vehicle-mounted speed measurement detector and the vehicle-mounted image acquisition sensor to acquire information, the vehicle-mounted radar detector is used for detecting the distance of a front vehicle and transmitting a radar wave signal to the front vehicle, the radar receiving device of the front vehicle receives the radar wave signal transmitted by a rear vehicle, a prompting horn in the vehicle is started to prompt a driver that the rear vehicle is coming, and meanwhile, a radar wave response signal is transmitted to the rear vehicle to prompt that the front vehicle of the rear vehicle has received the prompting signal; the vehicle-mounted speed measuring detector is used for measuring the driving speed, a safe distance is set in advance according to different vehicles and speeds, and the DSP controller controls the prompting form of the in-vehicle prompter according to the current vehicle speed and the relative distance of the front vehicle; when the front vehicle is within the safe distance and a driver of the rear vehicle continuously presses or holds a horn button, the front vehicle generates continuous rear coming vehicle prompt tones; when the front vehicle is out of the safe distance, the front vehicle only receives a rear coming vehicle prompt once, so that the rear vehicle is prevented from maliciously pressing a horn button; the vehicle-mounted image sensor is used for acquiring images of people within a safe distance in front of a vehicle, judging whether the people are pedestrians or not through image comparison and identification, and if the images of the pedestrians are acquired, forcibly starting the prompting loudspeaker outside the vehicle to prompt the pedestrians to pay attention to the coming vehicle and pay attention to safety;

wherein: the prompting form of the prompt device in the vehicle comprises 2 prompting forms: one is that: if no pedestrian is detected in the front of the vehicle body and in the safe distance between the left and right sides of the vehicle body, when the rear vehicle presses a horn, the front vehicle starts a prompting device in the vehicle, and a prompting sound for prompting the coming vehicle at the rear side appears in the vehicle; if a pedestrian is detected in front of the vehicle body and in the left-right safe distance, when the horn is pressed down in the vehicle, the prompting horn outside the vehicle is started to prompt the pedestrian to pay attention to the coming vehicle;

(3) meanwhile, a CAN bus communication interface matched with the vehicle type is reserved in the device, so that data sharing between the device and a vehicle-mounted control computer is realized, interconnection and intercommunication of vehicle-mounted equipment and the Internet of things are realized, and meanwhile, the reservation of the interface CAN facilitate the expansion of the equipment in the future; the CAN communication bus is respectively connected to CANL (pin 7)/CANH (pin 6) of a CAN communication bus processing chip SN65HVD232 through a pin 2 and a pin 3 of a DB9 interface, and the SN65HVD232 is connected with CANRX/CANTX pins of the DSP through R (pin 4)/D (pin 1).

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.