CN101585361A - Anti-collision and lane-departure-prevention control device for automobile - Google Patents

Abstract

The invention provides an automobile anti-collision lane departure prevention control device which is characterized by comprising a 77GHz millimeter wave radar, a CCD visual machine, a radar signal processing device, a video processing module, a vehicle-mounted display, a sensor, control software and a loudspeaker; 77GHz millimeter wave radar, CCD visual machine, radar signal processing device, video processing module, vehicle-mounted display, sensor, control software and speaker are connected by signal. By adopting the structure, the automobile radar ranging is combined with the machine vision object and the lane identification and judgment, so that the accuracy of preventing the automobile from colliding and deviating the lane is greatly improved, the false alarm rate of an anti-collision system is reduced, and the auxiliary active safety during driving is improved.

Description

Vehicle anti-collision and anti-lane departure control device

technical field

The invention relates to an automobile anti-collision safety control device, in particular to an automobile anti-collision and anti-lane departure control device.

Background technique

Compared with China's per capita GDP, the growth of China's auto industry is obviously faster. However, all kinds of road traffic accidents grow together with GDP and auto industry. According to the website of the Ministry of Public Security, there were 265,204 road traffic accidents across the country in 2008, resulting in 73,484 deaths, 304,919 injuries, and direct property losses of 1.01 billion yuan. As far as Guangdong Province is concerned, according to figures released by the Traffic Management Bureau of the Guangdong Provincial Public Security Department, there were 39,458 road traffic accidents in Guangdong in 2008, with 7,280 deaths, 46,960 injuries, and direct economic losses of more than 93 million yuan. The Chinese government has already felt the pressure of road safety, and strives to achieve a death rate of less than 5 per 10,000 vehicles within the limit of 2020. According to the available statistics, the death rate per 10,000 vehicles on Chinese roads is 9. In developed countries in Europe and the United States, there are 1 to 3 people. In order to achieve this goal, more advanced automotive active safety technologies must be gradually adopted. At the same time, after several years of rapid development in the Chinese market, consumers' demand for cars is shifting from satisfying basic transportation functions to pursuing higher-level needs such as comfort and safety. Among them, there is no doubt that safety considerations are factors that consumers pay more attention to. It is a typical example that active safety products such as ABS (anti-lock braking system) and ESP (electronically controlled driving stability system) have been equipped with high-end models in a very short period of time and now become standard equipment for various models. The accident forms of traffic accidents caused by cars running on the road mainly include frontal collision, side collision, tailgating collision, opposite scrape and same direction scrape and so on. These main forms of traffic accidents account for 80%-90% of all traffic accident forms. Therefore, how to reduce and avoid personal or property losses caused by collisions or scratches is an urgent problem to be solved at present.

Contents of the invention

The purpose of the present invention is to solve the deficiencies of the above-mentioned prior art, and adopt a multi-sensor active collision avoidance system, which can reduce to a large extent the automobile anti-collision and anti-lane departure control device that avoids personal or property losses caused by collisions or scratches .

The object of the present invention is achieved through the following technical solutions: automobile anti-collision and anti-lane departure control device, which is characterized in that it includes a 77GHz millimeter-wave radar, a CCD vision machine, a radar signal processing device, a video processing module, a vehicle display, and a sensor , control software and speakers; 77GHz millimeter wave radar, CCD vision machine, radar signal processing device, video processing module, vehicle display, sensors, control software and speakers are connected by signals.

The 77GHz millimeter wave radar adopts FMCW waveform and a quasi-optical lens antenna with dual feeds for transmitting and receiving.

The CCD vision machine is near-infrared black and white, requiring at least 300,000 pixels and 30 frames per second graphics acquisition capability. The lens is 12mm.

The sensors include a 77GHz millimeter-wave radar sensor, a front image sensor, and two side wide-angle image sensors.

The control software includes active collision fuzzy prediction software and anti-collision execution software.

Because the present invention adopts the above-mentioned structure, the 77GHz millimeter-wave radar is used for long-distance physical distance measurement of 0-200 meters; the CCD camera is used for analog distance measurement and object judgment of 0-100 meters, and the identification and judgment of yellow and white lines of the roadway; The processing module is used to receive and multi-frame cumulatively process the video signal for high-speed processing and judgment; the vehicle-mounted display is used to receive and display the vehicle distance and lane information after the radar ranging and video processing. The combination of automobile radar distance measurement and machine vision object and lane recognition and judgment of the present invention greatly improves the accuracy of automobile collision avoidance and lane departure prevention, reduces the false alarm rate of the collision avoidance system, and improves the active safety of assistance during driving.

Description of drawings

Fig. 1 is the schematic diagram of the automobile anti-collision anti-lane departure control device of the present invention;

Figure 2 is a schematic diagram of the structure of a 77GHz millimeter-wave radar;

Fig. 3 is an antenna structural diagram;

Fig. 4 is a schematic diagram of active collision fuzzy prediction;

Fig. 5 is a schematic diagram of anti-collision implementation.

Specific implementation cases

The present invention will be further described below in conjunction with accompanying drawing:

In Figure 1, the car anti-collision and anti-lane departure control device includes a 77GHz millimeter-wave radar, a CCD vision machine, a radar signal processing device, a video processing module, a vehicle display, sensors, control software and speakers; a 77GHz millimeter-wave radar , CCD vision machine, radar signal processing device, video processing module, vehicle display, sensors, control software and speakers are connected by signals. Sensors include radar sensors and video sensors, etc., which comprehensively process the multi-source information provided by multiple sensors of the same type or different types distributed in different locations, reduce the uncertainty of detection, and form a relatively consistent perception description of the system environment. In order to obtain an accurate and reliable analysis and judgment results, thereby improving the system's decision-making ability.

In Figure 2, the millimeter-wave anti-collision radar will use the triangular wave frequency-modulated FMCW waveform, which has the ability to measure distance and speed at the same time. According to the RCS of a typical vehicle and the atmospheric attenuation index of 77GHz, the radar action distance is not greater than 200m. Under normal circumstances, the radar transmission power needs about 20mW, and the triangular wave modulation bandwidth is selected to be 300MHz. According to the theoretical formula of distance resolution ΔR=kc/2B (where c is the speed of light, B is the bandwidth, k is the loss of signal processing, k=1.3～1.5) , the distance resolution ΔR=0.75m can be obtained. In addition, considering the linearity requirement of triangular wave modulation, as long as the linearity is better than 1m/150m=0.6%, the influence of FM nonlinearity on distance resolution can be basically ignored. If the speed measurement accuracy of single sweep measurement is required to reach 0.5m/s, the triangular wave sweep period needs to be at least 4ms. If considering the use of multi-cycle smoothing filter processing, the speed measurement accuracy of 0.5m/s can be achieved, and the frequency sweep cycle of less than 4ms can be used. The structure of the millimeter-wave radar system is shown in Figure 2, which mainly includes two parts: the front-end of the millimeter-wave radar and the real-time signal processor. Millimeter-wave radar ranging can use FMCW waveform or pulse waveform. If the ranging range is 1-200m, the pulse waveform commonly used for short-distance measurement is not easy to achieve. Therefore, this topic adopts FMCW waveform as the working mode of the millimeter-wave radar system. , the transmitter power is 20mW. If the distance resolution is 1m, then according to the distance resolution formula Δ=c/2Δf, the frequency sweep bandwidth can be selected as 300MHz.

The millimeter-wave radar front-end design includes several functional blocks such as the antenna module, VCO module, power generation module, down-conversion receiver module, and reference signal module, as shown in Figure 3 below:

1) Antenna module

The antenna beam is 3° in the elevation direction, and it needs to cover 9-12° in the azimuth direction. If one beam covers the direction, the accuracy of the target direction coordinates is too low, and three beams are used to cover.

2) VCO module

The oscillator circuit consists of a 12.75GHz VCO followed by a frequency tripler. A buffer amplifier at the VCO frequency and 38GHz reduces the sensitivity of the circuit to temperature and other influences. Tuning with a Schottky varactor. An external medium-Q passive resonator provides center frequency, temperature stability and best phase noise for a given frequency tuning range.

3) Power transmission module

The power transmission circuit includes a frequency multiplier, which multiplies the 38GHz signal input by the local oscillator to 76GHz, followed by a medium power amplifier. This circuit has a main channel output and a secondary channel output. The primary channel output is radiated from the transmit antenna, and the secondary channel output is used as the local oscillator for the down-conversion receiver.

4) Down conversion receiver module

The down-conversion receiving module is used to convert the signal reflected by the target to an intermediate frequency and send it to the signal processing module for processing. This module needs to have lower low-frequency noise.

5) Reference signal module

This module includes a high quality fixed frequency oscillator and a second harmonic mixer. A buffer amplifier is also used to ensure improved performance over a wide range of environmental conditions, and the oscillator must be coupled to an external high-Q resonator for stability and phase noise performance.

In Figure 4, the collision prediction system estimates the possibility of the car colliding with other obstacles on the road based on various information collected by the sensor, or unintentionally deviates from the lane line without turning on the turn signal, and determines the current driving safety state and early warning mechanism, the collision prediction system needs to adjust parameters in real time and switch between various driving states in real time according to the actual situation on the road. The input of each sensor of the collision prediction system and the control characteristics of the actuator are nonlinear and time-varying. Each subsystem has its own information processing mechanism and control strategy. Since the collision prediction system needs to consider various characteristics in the system operation in time, such as state time gradient, discrete event dynamics and jump phenomena, control state switching and logic commands, etc., It is precisely because of the actual road conditions and the complexity of the structure and working process of the collision prediction system that its control strategy is more complex and robust than passive collision avoidance. Therefore, the active collision prediction system adopts fuzzy control technology, and the active collision The main task of the fuzzy prediction system is to establish parametric and non-parametric models for the road environment, driving state, sensor input, control parameters, execution feedback and the operating state parameters of each subsystem, in order to find the best system model, and use local optimization Strategy, for each parameter, such as the moving speed and direction of the obstacle, the expected collision time and probability, the vehicle speed estimation, the execution feedback time, the optimization of a limited number of cycles, the actual output and the model output are constantly compared and feedback corrections are made to achieve Track reference values. Its advantages are: due to the use of limited but important parameters for each optimization, the optimization calculation amount and system response time are greatly reduced; at the same time, the rolling strategy is used to achieve global optimization on the basis of local optimization; at the same time, feedback correction is used. Uncertain problems such as system interference are solved, and communication between subsystems is realized by CAN bus.

In Figure 5, the anti-collision actuator is mainly composed of three modules: sound and light alarm, active deceleration, and emergency braking. The sound and light alarm is converted into the size and content of the warning sound according to the current speed of the vehicle, the time of the predicted collision, and the distance from the obstacle, and with the corresponding alarm signal light, the sound reminder prompts the direction of the collision. The interval time of the sound prompts the degree of danger and the distance of the obstacle; the active deceleration converts the distance of the obstacle into the speed requirement for the car according to the current speed and the driver's actions (acceleration pedal travel, brake pedal travel and gear signal) , and through the speed-torque control module, it is transformed into the output torque demand of the engine; the speed-torque control module is mainly responsible for the speed or the torque fluctuation generated during the shifting and mode switching of the car, and corrects the output of the torque distribution module The torque of the engine is controlled to meet the smoothness of the automatic deceleration of the vehicle; the emergency braking module automatically issues a braking command when the driver cannot make an effective braking action according to the driver's reaction speed and the current predicted collision time To the braking control conversion module; the braking control conversion module converts the braking torque and braking torque into the braking torque and output to the braking mechanism of the vehicle according to the speed of the vehicle and the distance and speed of obstacles to control the braking of the vehicle.

The above is a specific embodiment of the present invention, but those skilled in the art can still make solutions that do not depart from the present invention and still fall within the protection scope of the present invention.

Claims (5)

1. Automobile anti-collision and anti-lane departure control device, which is characterized in that it includes a 77GHz millimeter wave radar, a CCD vision machine, a radar signal processing device, a video processing module, a vehicle display, sensors, control software and speakers; a 77GHz millimeter wave radar , CCD vision machine, radar signal processing device, video processing module, vehicle display, sensors, control software and speakers are connected by signals. 2. The vehicle anti-collision and anti-lane departure control device according to claim 1, characterized in that the 77GHz millimeter-wave radar adopts FMCW waveform and a quasi-optic lens antenna with dual transceiver feeds. 3. The vehicle anti-collision and anti-lane departure control device according to claim 1, characterized in that the CCD vision machine is near-infrared black and white, requires at least 300,000 pixels, and 30 frames per second graphics acquisition capability. The lens is 12mm. 4. The vehicle anti-collision and anti-lane departure control device according to claim 1, characterized in that said sensors include a 77GHz millimeter-wave radar sensor, a front image sensor, and two side wide-angle image sensors. 5. The vehicle anti-collision and anti-lane departure control device according to claim 1, characterized in that said control software includes active collision fuzzy prediction software and anti-collision execution software.

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