CN1940569A

CN1940569A - Fatigue-driving warning device on highway by acceleration method

Info

Publication number: CN1940569A
Application number: CN 200610124441
Authority: CN
Inventors: 李曙光
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-09-01
Filing date: 2006-09-01
Publication date: 2007-04-04

Abstract

A dangerous alarm of fatigue driving on highway consists of horizontal acceleration transducer and forward acceleration transducer, two amplifiers for receiving and amplifying signals from two said transducers, microprocessor CPU for receiving and storing and analyzing signal from amplifiers then issuing alarm signal, alarm for receiving alarm signal sent by microprocessor CPU and A/D converter for making A/D conversion on signals amplified by two said amplifiers.

Description

Fatigue-driving warning device on highway by acceleration method

Technical field

The present invention relates to a kind of warning device of fatigue driving motor vehicle, relate in particular to a kind of fatigue-driving warning device on highway by acceleration method.

Background technology

Therefore fatigue driving has caused the great attention of each side in recent years turnpike driving " first killer ".Except administrative authority erects " forbidding fatigue driving " warning sign on the way at highway, also have some driver's quantitative refuelings, force the own rest of stopping because want continuous makeup oil amount.Also have some well-known automobile production manufacturers to drop into manpower and materials and study how early detection fatigue driving, warning in time is to prevent dangerous pernicious traffic accident.

According to the science and technology column Chinese Central Television (CCTV) in February, 06: European Volvo AB is just adopting a kind of method to attempt " S " type running orbit that early detection is felt sleepy and caused blurred vision, direction control shakiness to occur because of fatigue for finding and the warning fatigue driving.Their method is: a camera is installed, the white imaginary point tag line on this camera picked-up road surface on pilothouse front glass window.Set up a straight line equation according to the image that is absorbed, reuptake one width of cloth new images is at interval at regular intervals set up a new straight-line equation then.Front and back two equations are made comparisons: if automobile is along the track cruising, two straight lines should be parallel to each other so, otherwise just have certain included angle.Continuous like this go down constantly measure, constantly relatively, the size and the cycle of calculating their variable angle, just can find therefrom that automobile is a normal straight-ahead operation, still change trains, turning or " S " type twist and travel.This research achieves initial success.Can in time find " S " type movement locus under normal conditions, and in time give the alarm.But descend in rainy day, snow sky, greasy weather visual isopter condition of poor, just be difficult to obtain satisfied image.This program has also been reported the another kind of fatigue driving warning against danger device that U.S. Ford is also being studied simultaneously.They make the glasses shape with this device, load onto photoelectric measuring head on two picture frames, are used for observer's the motion of two eyelids, attempt early detection and droop because of fatigue two eyelids that produce of feeling sleepy, thereby in time give a warning, and prevent accident.Difference is very big but the blinking of human eye varies with each individual, and judges fatigue as feature in view of the above, and reliability is relatively poor.For just having on the driver of glasses or sunglasses originally, wear once secondary measurement mirror difficult more in addition.Thereby limited its use.

Summary of the invention

The objective of the invention is to: the deficiency that remedies prior art, a kind of acceleration method highway fatigue driving warning against danger is provided, make it not to be subjected to the influence of uncertainties such as weather, visibility, personal habits, bonding position, amplitude, cycle, these features of slope, reliably " S " type movement locus is changed from keeping straight on, turn left to change, turning right etc. the running mode and differentiate that realization is carried out monitoring, alarming to the automobilism track in the highway fast running.

The present invention realizes by following scheme: comprise that be the forward acceleration sensor of forward acceleration in order to differentiate automobile because of the deceleration that the lateral acceleration sensor that turns to the transversal displacement that brings reaches in order to measured automobiles; Two in order to receive the amplifier that two sensors produces signal and signal carried out processing and amplifying; Pair amplifier output signal storage and carry out analyzing and processing, the microprocessor CPU of the signal that gives the alarm; In order to receive the give the alarm warning horn of signal of microprocessor CPU.

The present invention also comprises two A/D converters that carry out the A/D conversion in order to the amplifying signal with the output of two amplifiers.

The present invention is for simplifying circuit, improve its integrated level, lateral acceleration sensor, forward acceleration sensor and two amplifiers are integrated into X, Y twin shaft acceleration analysis integrated chip, the universaling I/O port of microprocessor CPU connects a triode, in order to the conducting of controlling this triode with end, transistor collector connects warning horn, with the whether warning of control.

The present invention in parallel one mu balanced circuit that constitutes by triode, biasing resistor and series arm of light emitting diode and current-limiting resistance between microprocessor CPU power supply VCC end pin and ground, and direct supply, power switch are set.

As long as the directive change of the automobile that the present invention runs at high speed, the output valve of horizontal accelerometer will change.It is not subjected to the influence of uncertainties such as weather, visibility, personal habits and reflects the running orbit of automobile objectively.Sampled data is bonding position, amplitude, cycle, these features of slope behind digital filtering, can be very reliable " S " type movement locus be changed etc. the running mode discriminating from keeping straight on, turn left to change, turning right and come out.This working of an invention scheme is also very succinct, simple in structure, volume is little, cost is low, effective, can realize the automobilism track in the highway fast running is carried out monitoring, alarming.

Description of drawings

Fig. 1 is a principle of the invention block diagram;

Fig. 2 is a circuit diagram of the present invention;

Fig. 3 is a motor vehicle forward direction shift simulation diagrammatic sketch of the present invention;

Fig. 4 is motor vehicle transversal displacement simulation diagrammatic sketch of the present invention.

Embodiment

The present invention is described in detail to contrast accompanying drawing below in conjunction with embodiment.

The present invention includes in order to differentiate automobile is the forward acceleration sensor FY of forward acceleration because of the deceleration (negative acceleration) that the lateral acceleration sensor FX that turns to the transversal displacement that brings reaches in order to measured automobiles; Two in order to receive amplifier X, the Y that two sensors FX, FY produce signal and signal carried out processing and amplifying; Two A/D converter MX, MY that carry out the A/D conversion in order to amplifying signal with amplifier X, Y output; Pair amplifier output signal storage and carry out analyzing and processing, the microprocessor CPU of the signal that gives the alarm; In order to receive the give the alarm warning horn F of signal of microprocessor CPU.Lateral acceleration sensor FX of the present invention, forward acceleration sensor FY and amplifier X, Y are integrated into X, Y twin shaft acceleration analysis integrated chip IC1.Twin shaft acceleration analysis integrated chip IC1 pin 15 and 5 on pin also are connected to capacitor C 1, C2, its output terminal pin 12,10 connects microprocessor CPU IC2 input pin 12 pin and 13 pin are data port P1.0, P1.1, capacitor C 1 is a power filtering capacitor, and capacitor C 2 is even electric capacity for high frequency moves back.Difference cross-over connection filter capacitor C3, C4 between twin shaft acceleration analysis integrated chip IC1 output terminal pin 12,10 and ground, the universaling I/O port P3.7 of IC2 connects triode T1 base stage, in order to the conducting of control triode T1 with end, triode T1 collector meets warning horn F, and triode T base stage is connected to base biasing resistor R1.In parallel one mu balanced circuit that constitutes by triode T2, biasing resistor R2, R3 and the series arm of light emitting diode D1 and current-limiting resistance R5 between microprocessor CPU IC2 power supply VCC end pin 20 and ground, and direct supply E, power switch K and resistance R 4, R6, resistance R 4 and the series arm cross-over connection microprocessor CPU IC2 power supply VCC end pin 20 of power switch K and the anode of direct supply E be set.

Principle of work of the present invention is as follows: twin shaft acceleration sensor lateral acceleration sensor FX, forward acceleration sensor FY will export to y-axis amplifier Y and x axis amplifier X respectively from the accekeration of y direction of principal axis and the variation of x direction of principal axis.The acceleration signal that amplifies through amplifier X, Y becomes d. c. voltage signal Xout, yout.The output valve of two-way amplifier is stabilized on the numerical value that 1/2 supply voltage is 1.5V at ordinary times.When accekeration changed, the output valve of amplifier also changed.The range value that changes is 175mv/G, the DC voltage output valve of positive 1G acceleration is 1.5V+175mv=1.675V, the DC voltage output valve of negative 1G acceleration is 1.5V-175mv=1.325V, A/D converter is sent in the DC voltage output of amplifier, and A/D converter is converted to 8 binary codes with d. c. voltage signal.Conversion formula is D=Vin*256/Vcc, and wherein Vin is the input analog amount of A/D converter, the output quantity out of amplifier just, and Vcc is a supply voltage, D is the digital quantity after the conversion.When power supply was got 3V, conversion formula was D=Vin*256/3

Example: acceleration=0 o'clock, Vin=1.5V, D=1.5*256/3=128 (decimal system) or 10000000 (scale-of-two);

During acceleration=1G, Vin=1.675V, D=1.675*256/3=143 (decimal system) or 10001111 (scale-of-two)

Acceleration=-during 1G, Vin=1.325V, D=1.325*256/3=113 (decimal system) or 01110001 (scale-of-two)

X-axis digital quantity after the conversion is taken out by CPU, again through digital filtering (removing undesired signal), carries out track then and judges, if find it is that " S " type distortion that alters course is repeatedly travelled, then triggers alarm F.This moment, CPU transferred test Y-axis acceleration signal to, if measured retarded velocity (negative acceleration), then the explanation warning has caused that the driver payes attention to, and had taked the correct measure of slowing down, and this moment, the CPU output signal was closed alarm, continued the next round monitoring.If do not detect reduce-speed sign after reporting to the police, then report to the police, till the driver reacts always.Digital filtering software and " S " type track judge that the software supervisor is placed in the program storage.

As shown in Figure 3, T0 constantly, automobile is kept straight on forward with speed v along the y direction, at this moment, Y direction speed Vy=V, directions X speed Vx=0 (ignore because of a little shake of Uneven road, direction etc. may bring vehicle body about slightly rock).

As shown in Figure 4, T1 constantly, when automobile during by deflection θ of craspedodrome Y direction deflection left, because of inertia effect, automobile still with V speed to the headstock direction running.This moment Y direction speed Vy=Vcos θ, directions X speed-Vx=Vsin θ, cross measure this moment accelerometer will have output ax=dVx/dt, (differential of speed is an acceleration).Otherwise, if automobile to right avertence θ angle, then draws Vy=Vcos θ, Vx=Vsin θ easily.By last analysis as can be known, can learn that by the output valve of transverse acceleration meter automobile is a straight-line travelling, still changed course left or changed course to the right, travel (" S " type track) continuously still alters course.Y directional acceleration instrumentation amount retarded velocity, the warning that is used for clearing (because of the driver takes the deceleration measure, is that correct reaction has been made in warning.)

Twin shaft acceleration analysis integrated chip IC1 model is ADXL320, and IC2 is the high-performance one-chip computer, and model is STC12LE2052AD.Therefore functional units such as IC2 inner self-contained rom, ram, cpu, a/d conversion, oscillator, electrification reset just can directly not use as any expansion.CPU was 10 point/seconds to this sampling rate of two mouthfuls.Whether only to the P1.0 sampling, paying close attention to automobile had unusual transverse acceleration to change when CPU was flat, had only the variation that just transfers monitoring forward acceleration Yout after the warning to, saw whether the driver has taked the deceleration measure.1 pin of IC2 is the external reset pin, with its ground connection, and then need not external reposition element for internal reset.The P3.7 of IC2 here uses as universaling I/O port.It is used for controlling the conducting of triode T1 and ending.During operate as normal, the P3.7 output low level is ended triode T1, and sonic alarm F can not get electric current, and sounding does not ring.When occurring needing to report to the police unusually, P3.7 exports noble potential, and at this moment, the T1 base stage obtains electric current by resistance R 1 and makes the T1 conducting, and hummer J gets the electric sound that sends.D1 is a red light emitting diodes, and when power switch K connected, its conducting was luminous.Power supply E is a rechargeable battery, but by current-limiting resistance R6 external automobile cigar lighter 12V power supply it is charged.Because of the used element power consumption of this circuit extremely low (working current is less than 7mA), abundance once electricity can be worked more than 20 hours.

Claims

1, a kind of fatigue-driving warning device on highway by acceleration method is characterized in that: comprise that be the forward acceleration sensor (FY) of forward acceleration in order to differentiate automobile because of the deceleration that the lateral acceleration sensor (FX) that turns to the transversal displacement that brings reaches in order to measured automobiles; Two in order to receive the amplifier (X, Y) that two sensors (FX, FY) produces signal and signal carried out processing and amplifying; Pair amplifier output signal storage and carry out analyzing and processing, the microprocessor CPU of the signal that gives the alarm (IC2); In order to receive the give the alarm warning horn (F) of signal of microprocessor CPU (IC2).

2, fatigue-driving warning device on highway by acceleration method according to claim 1 is characterized in that: also comprise two A/D converters (MX, MY) that carry out the A/D conversion in order to the amplifying signal with amplifier X, Y output.

3, fatigue-driving warning device on highway by acceleration method according to claim 1 and 2, it is characterized in that: lateral acceleration sensor (FX), forward acceleration sensor (FY) and amplifier X, Y is integrated into X, Y twin shaft acceleration analysis integrated chip (IC1), twin shaft acceleration analysis integrated chip (IC1) output terminal pin (12,10) connect microprocessor CPU (IC2) input pin (12) pin and (13) pin, twin shaft acceleration analysis integrated chip (IC1) output terminal pin (12,10) cross-over connection filter capacitor (C3 respectively and between ground, C4), the universaling I/O port P3.7 of microprocessor CPU (IC2) connects triode (T1) base stage, in order to control triode (T1) conducting with end, triode (T1) collector connects warning horn (F), and triode (T1) base stage is connected to base biasing resistor (R1).

4, fatigue-driving warning device on highway by acceleration method according to claim 1 and 2, it is characterized in that: in parallel one mu balanced circuit that constitutes by triode (T2), biasing resistor (R2, R3) and the series arm of light emitting diode (D1) and current-limiting resistance (R5) between microprocessor CPU (IC2) power supply VCC end pin (20) and ground, and direct supply (E), power switch (K) and resistance (R4, R6) are set, series arm cross-over connection microprocessor CPU (IC2) the power supply VCC of resistance (R4) and power switch (K) holds the anode of pin (20) and direct supply (E).