CN2119640U - Digital display recorder for going parameters of automobile - Google Patents

Abstract

The utility model relates to a digital display recorder for going parameters of automobile used for displaying and recording the going parameters of automobile. The utility model is an instrument in which a digital instrument and a monitor for going parameters of automobile are combined as a whole, and the parameters of standard time used for control stations, momentary vehicle speed, going mileage, going time, the change of vehicle speed within 15 seconds before stopping, etc. are provided for managerial departments of traffic control and transportation. A single-chip computer is used as a core, the going parameters tested by a sensor are directly provided for drivers by a digital displayer to make the drivers know the condition of automobile going. The relevant parameters are recorded by the utility model simultaneously, and when necessary, the electric supply way of low electricity consumption of backup electrical source is used and read out from the displayer.

Description

Digital display recorder for going parameters of automobile

The utility model is a kind of device that is used to show and write down the driving parameter of automobile, and it provides service for driver and managerial personnel.

At present, digital instrument display system and parameter monitoring system have been considered to one of developing direction of automobile electronics.Though domestic existing people has made a few thing, but often only consider an aspect or individual data, show imperfection in the system and the imperfection on the data, function singleness, fail to give full play to the effect of micro computer, data are imperfect, and important time parameter and other relevant parameter can not be provided.

The purpose of this utility model is: give full play to the function of micro computer, provide the digital instrument system of a cover to increase the accuracy of data indication and the convenience of interpretation.Simultaneously, this cover system also will be noted some important driving parameters, for the scientific of traffic administration, transportation management offered help.When the utility model used as instrument, its instruction content mainly contained the standard time (Beijing time) instantaneous speed of a motor vehicle, mileage, running time etc.Simultaneously, this instrument leaves the interface with other automobile instrument or sensor, can indicate other data.The utility model is when showing the driving parameter, automatically noted related parameter, comprise this mileage, this is driven a vehicle the used time (not containing down time), the max speed and time of origin (Beijing time) in this driving, stop speed of a motor vehicle situation of change and down time (Beijing time) in preceding 15 seconds accumulative total mileage, accumulative total running time (not containing down time).Parameter relevant with the speed of a motor vehicle in the above-mentioned parameter provides for vehicle supervision department, and other parameter then can be used for transportation management.

The utility model is achieved through the following technical solutions:

Fig. 1 is its principle calcspar, and wherein: 1 is vehicle speed sensor, and 2 is other parameter sensors, 3 is pulse shaping and match circuit, 4 is counter, and 5 is multiway analog switch, and 6 is A/D converter, 7 is one-chip computer and peripheral circuit, 8 is the radix point decoding scheme, and 9 for figure case selects signal decoder, and 10 is that digital section is selected signal decoder, 11 is charactron, 12 is mini-printer, and 13 is automobile storage battery, and 14 is sample circuit, 15 is mu balanced circuit, 16 is charging control circuit, and 17 are the backup storage battery, and 18 is the controllable silicon commutation circuit, 19 is diode network, 20 are the circuit except that single-chip microcomputer and a small amount of peripheral circuit, and 21 is the vehicle switch, and 22 is operation keyboard, from systemic-function, it is the integrative instrument that integrates digital instrument and parameter recorder.

The measurement of time is to the crystal oscillator signal frequency split and regularly to obtain with " second " through timer internal be the time quantum of unit by one-chip computer 7 inner frequency dividing circuits.Registering instrument utilizes " second " reference signal, forms a standard twenty four hours system clock on the one hand, indicates Beijing time to the driver, is the interlude control signal for timing sampling provides with one second on the other hand.

Fig. 3 is the vehicle speed sensor circuit diagram; The measurement of the speed of a motor vehicle is that vehicle speed sensor 1 adopts integrated Hall element to measure the speed of a motor vehicle, and it is a central rotating shaft formula assembly, and magnet steel is fixed in the rotating shaft, rotates with rotating shaft.Hall element is fixed on the shell, and whole component string is connected on the end of the flexible axle that connects the original speed of a motor vehicle/mileometer, and any structure that need not street rod does not influence the function of original instrument.The vehicle speed sensor output signal reaches the counter of being made up of 7,4LS,390 4 by shaping pulse and match circuit 3 and sends into one-chip computer 7, and the vehicle speed sensor profile is a bolt shape, is easy to install.When running car, the rotating shaft that flexible axle drives on the vehicle speed sensor 1 is rotated, and Hall element converts vehicle speed signal to frequency proportional with it pulse signal, and is defeated through one-chip computer 7.

If the speed of a motor vehicle is v, flexible axle rotating speed is n, then:

v＝kn

K is a scale-up factor.If the magnet steel number is N, then the output signal frequency of Hall element is: f=Nn

Therefore, the speed of a motor vehicle:

v＝kf／N

Because the sampling interval to vehicle speed signal is one second, and adopt the mode frequency measurement of pulse signals counting.Therefore, count in one second and be pulsed frequency f.

Because the least count value is 1, therefore, minimum distinguishable speed (being resolution) is

v＝k／N

This formula shows that speed of a motor vehicle resolution and magnet steel number are inversely proportional to.For avoiding vehicle speed sensor 1 volume excessive, get N=4.

The utility model is that core realizes Signal Processing with one-chip computer 7.After acquisition time, vehicle speed signal, can obtain desired data through the appropriate location reason.

Known v=kf/N

Order: k=k/N

Then have: v=kf

For a certain type automobile, k is a constant.

Behind the one-chip computer 7 enabling counting devices 4,, after gate time reaches one second, read count value f, can calculate speed of a motor vehicle v according to following formula by the internal timing control time.

When the speed of a motor vehicle was known, mileage calculated as follows:

Known 1 kilometer/hour equals 0.2778 meter per second, and this shows that when the speed of a motor vehicle was 1 kilometer/hour, automobile travelled 0.2778 meter in 1 second.Therefore if the speed of a motor vehicle is v(kilometer/hour), then distance travelled is a 0.2778(rice in 1 second).

Secondary data is pursued second at one-chip computer 7 add up, can obtain the distance travelled of automobile.

In order to be adapted to different vehicles, accomplish a tractor serves several purposes, be provided with vehicle switch 21, Fig. 2 is vehicle on-off circuit figure; One-chip computer will read on off state when calculating v, judge this device instrument on that a kind of vehicle, thereby selects the rational proportion coefficient k.

In order to write down the preceding 15 seconds speed of a motor vehicle situation of change of brake, the utility model adopts the mode of cycle index, remains the speed of a motor vehicle and be any vehicle speed data of zero per second in preceding 15 seconds, notes the speed of a motor vehicle simultaneously and be zero the moment.

Corresponding simulating signal is read in after A/D converter 6 converts parallel digital signal in the one-chip computer 7 by other parameter sensors 2 for other parameter (as fuel consumption, ton kilometre etc.), calculate through one-chip computer 7 and can obtain relevant parameter.Outside warp let-off charactron 11 demonstrations in real time of speed of a motor vehicle quilt, other parameter is deposited in one-chip computer 7 internal RAM, and the parameter of need being selected by operation keyboard 22 shows and printing.Fig. 4 is the radix point decoding scheme: the radix point decoding scheme of being made up of 74L,S04 8, the figure case that is made of 74LS138 selects signal decoder 9, select signal decoder 10 by the digital section that CD4511 forms, six light emitting diode charactrons are formed charactron 11, select signal decoder 9, digital section to select signal decoder 10 from the signal of one-chip computer 7 outputs through radix point code translator 8, figure case, deliver to charactron 11 and demonstrate corresponding data, also can print corresponding data simultaneously by mini-printer 12.

Data such as the utility model record accumulative mileage for fear of being caused loss of data because of changing reasons such as storage battery, adopt dual power supply.When certain reason can't be powered automobile storage battery 13, be loaded on backup storage battery 17 automatic power under charging control circuit 16 effects of device inside, so that keep data.This mode can make the data of record remain in mishap.For the power-on time that prolongs backup storage battery 17 should reduce power consumption as far as possible, the way of taking is that backup battery is only powered to the one-chip computer 7 that contains data-carrier store when making the automobile storage battery outage by diode network 19.

Consider that automobile storage battery will provide energy for automobile starting, should consume storage battery institute accumulate energy less when stopping in the automobile long period, in order to avoid the influence starting, this device stores cumulative data as far as possible, can not cut off the power supply during parking of automobile, so must reduce supply current in this case.

Fig. 5 is a power circuit, it is sample circuit (14 among Fig. 1) that the automobile storage battery (13 among Fig. 1) of 12v and backup storage battery (17 among Fig. 1) R4C of 6v are arranged, DG2, DG3 form charging control circuit (16 among Fig. 1), DG4, TIC106 form controllable silicon commutation circuit (18 among Fig. 1), 7805 constitute mu balanced circuit (15 among Fig. 1), D, D, D form diode network (19 among Fig. 1), in order to reduce supply current, take following method: when the speed of a motor vehicle is zero, single-chip microcomputer is exported non-binary-coded decimal to the BCD seven-segment decoder, closes display.This makes the pressure drop on sample circuit 14 in the power circuit, the R4C reduce, and DG3 transistor base current potential rises, and causes DG2 transistor base current potential to descend, and DG2 is in cut-off state, stops through the charging of backup storage battery.After closing display and charging circuit, supply current drops to 0.31A from 0.6A.This is of great use to down time than long situation.

Because display is closed by software operation, therefore, when pressing operation keyboard 22, display still can be worked, but it is closed again after by preset program data presentation being finished automatically.Behind the start, display recovers operate as normal automatically, and simultaneously, the charging circuit of backup battery is also worked.At this moment, because automobile current generator is being given its storage battery charging, the electric energy of therefore noting down instrument consumption is in fact from generator.

Claims (1)

1, a kind of digital automobile driving parameter display recorder, partly form by vehicle speed sensor, one-chip computer, display, power supply etc., it is characterized in that: vehicle speed sensor is to adopt integrated Hall element, the kind of one-chip computer output signal is by behaviour's Keyboard Control, display is made up of the digital pipe of six diodes, and power supply is made up of dual power supply.

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