CN2258608Y

CN2258608Y - Measuring instrument for airplane fuel quantity

Info

Publication number: CN2258608Y
Application number: CN95222463U
Authority: CN
Inventors: 吴明玉
Original assignee: Beihang University
Current assignee: Beihang University; Beijing University of Aeronautics and Astronautics
Priority date: 1995-09-28
Filing date: 1995-09-28
Publication date: 1997-07-30
Anticipated expiration: 2005-09-28

Abstract

The utility model discloses a measuring instrument for airplane fuel quantity The utility model comprises a power supply, a sensor, a microcomputer and a display, wherein, two redundancy fault-tolerance test circuits used for the instrument are mainly composed of two identical hardware channels A and B, wherein, the A channel has the structure that a single-chip computer 8089 (1) is respectively connected with a connected storage RAM and a fault recognition circuit (1), the RAM and the fault recognition circuit are simultaneously connected with a fault isolation circuit, the fault isolation circuit is connected with an LCD driver, and the LCD driver is connected with the LCD display. The B channel has the structure that a fault recognition circuit (2) is connected with an alarm and not connected with the fault isolation circuit and the other connections are the same as the A channel. The utility model has the advantages of high precision and good reliability.

Description

The aircraft fuel oil tester

The utility model relates to a kind of single-chip microcomputer two remaining tolerating measure circuit that are used for the aircraft fuel oil tester, and the test (containing control) that this circuit can be widely used in a plurality of simulations, digital quantity belongs to electronic technology.

At present, single-chip microcomputer test circuit commonly used in the aircraft fuel oil tester is normally single pass, does not have fault-tolerant ability, when system breaks down, just can loss of function, even damage equipment.

In order to overcome above-mentioned deficiency, the purpose of this utility model is: design a kind of single-chip microcomputer two remaining tolerating measure circuit that can be used in the aircraft fuel oil tester, when one of following fault (A/D conversion unreasonable as power supply power-fail, software fault, sensor output data, single-chip microcomputer makes mistakes, cpu logic mistake, RAM read and write mistake) appears in system, reaching primary fault works on, secondary failure is sent warning, to improve the reliability of tester test.

A kind of aircraft fuel oil tester of the utility model, include power supply, sensor, microcomputer and demonstration, wherein: the two remaining tolerating measure circuit that are used for this instrument mainly are made up of two identical hardware corridors of A and B, wherein A channel is: single-chip microcomputer 8098 (1) connects RAM and fault identification circuit (1) respectively, RAM is connected the fault isolation circuit simultaneously with fault identification circuit, the fault isolation circuit connects lcd driver, and lcd driver connects LCD display; The B passage is: single-chip microcomputer 8098 (2) connects RAM and fault identification circuit (2) respectively, and fault identification circuit (2) connects reports to the police, and RAM connects the fault isolation circuit, and the fault isolation circuit connects lcd driver, and driver connects LCD display.

Fault identification circuit in A and the B passage mainly by: the monostable circuit 74LS122 that can heavily trigger, comparer LM339, rejection gate 74LS27 and phase inverter 74LS04 form, and the fault isolation circuit is made up of phase inverter 74LS04 and four analog switches 4066; Its circuit connecting relation is:

The A1 pin of 74L122 connects the reset terminal RESET of single-chip microcomputer 8098, B1, B2, CLR meets 5V simultaneously, the A2 pin connects the tie point of resistance R 1 and capacitor C 1, the other end of R1 connects 5V, the other end ground connection of C1, series resistor R2 and capacitor C 2 between 11 pin of 74LS122 and 14 pin, 13 pin connect the tie point of R2 and C2, the Q end of 74L122 connects the 3rd pin of rejection gate 74LS27, the 1st pin of phase inverter 74LS04 connects the P2.0 end of single-chip microcomputer 8098, output terminal the 2nd pin of comparer LM339 connects the 5th pin of rejection gate 74LS27, the 5th pin of LM339 connects low level V1, the 4th pin of LM339 connects power supply electricity VC, the 3rd pin that the 6th pin of 74LS27 connects phase inverter 74LS04 connects analog switch 4066 (1) simultaneously, (2) E end, the 4th pin of phase inverter 74LS04 connects analog switch 4066 (3), (4) E end, the X end of analog switch 4066 (1) (2) connects the AD-3 and the AD4 of single-chip microcomputer 8098 (1) respectively, 5, WR, the Y2 end, analog switch 4066 (1), (2), (3), (4) Y end connects the input end of lcd driver.

The utility model has the advantages that:

Because the utility model has been realized single-chip microcomputer two remaining tolerating measure technology, it and present domestic single channel system commonly used ratio have been improved reliability greatly.Debugging is made easily, and is cheap.The utility model has also adopted TSC7211AM LCD driven display technique, it and present domestic light-emitting diode display commonly used ratio, the little several magnitude of working current, three times of thin thickness, making that system power dissipation is low, volume is little, be specially adapted to portable instrument, is the developing direction of display technique.In a word, the utility model can be widely used in various test macros, will obtain good economic benefit.

The utility model has following accompanying drawing: Fig. 1 microsystem hardware block diagram Fig. 2 fault identification circuit and fault isolation circuit theory diagrams Fig. 3 lcd driver and LCD display circuit diagram

Element is as follows among the figure: monostable circuit LM339 comparer 74LS27 rejection gate 74LS04 phase inverter R1, R2 resistance C1, C2 electric capacity that 8098 single-chip microcomputer LCD flat panel LCD LCD DRIVE driver RAM static memory (6264,62256) 74L122 can heavily trigger

Now conjunction with figs. describes the course of work of the present utility model in detail: the microsystem hardware block is made up of two (A and B) identical hardware corridors as shown in Figure 1.This figure has omitted known part in the test macro, as address decoding, driving or the like.LCD is plate of flat liquid crystal display (can select homemade 4002SH model for use) among the figure.LCD drives the special-purpose driving circuit (can select the product TSC7211AM of U.S. TELEDYNE SEMCONDUCTOR company for use) for computer-controlled LCD.RAM is general static memory (can select 6264,62256 for use).Warning circuit is a knowledge.Fault Identification and buffer circuit are seen below and are stated content.

Line between sensor, 8098 single-chip microcomputers, the RAM is known content, and line graph slightly.

Fault Identification and buffer circuit can heavily trigger the phase inverter 74LS04 composition fault identification circuit on monostable circuit 74LS122, comparer LM339 rejection gate 74LS27 and the left side as shown in Figure 2.The phase inverter 74LS04 on the right side and four analog switches 4066 are formed the fault isolation circuit.The A1 pin of 74LS122 meets 8098 single-chip microcomputer reseting terminal RESET, and when software fault, the supervision timer WATCH DOG of 8098 single-chip microcomputer inside provides reset signal, and the Q end output high level of 74LS122 is the software fault diagnosis signal.The effect of A2 pin external circuits R1 20K, the C1 100 μ F of 74LS122 is the elimination system bogusware failure diagnosis information that 8098 single-chip microcomputer reset signals cause when powering on.Other pin of 74LS122 are connected to knowledge, not tired stating.The LM339 in-phase input end connects supply voltage and allows low level V1, and inverting input meets practical power voltage VC, and when VC＜V1, LM339 exports high level, is the power supply power-fail fault-signal.When other faults occur, write 0,, be other fault diagnosis signals through the 74LS04 on left side output high level through software diagnosis and at the P2.0 of 8098 single-chip microcomputers mouth.The output terminal of 74LS27 connects the control end E of two 4066 in face, and two 4066 control ends below the 74LS04 on the right side connects.The data of passage A, B and control signal (AD0-AD5, WR, Y) meet upper and lower two 4066 switch input terminal X respectively, and data, position choosing, sheet that 4066 output switching terminal Y meets LCD driving circuit TSC7211AM select input end.When powering on, system is normal, and 74LS27 exports high level, makes top two 4066 switch conduction, and the A channel data can be sent demonstration.When above-mentioned arbitrary fault appearred in system, the 74LS27 output low level was cut off two 4066 switch, the switch that conducting is following two 4066, and then the information of A channel is isolated, and the signal of B passage can send demonstration.When the B passage also one of above-mentioned fault occurred, after diagnosing, system was reported to the police.

LCD driving and LCD display circuit are as shown in Figure 3.4002SH is 7 sections four plate of flat liquid crystal display, totally 40 pins, and wherein 28 is Duan Xuanduan, 2 is the backplane signal wire.Duan Xuanyu backplane signal is the square-wave voltage of 125HZ, the two anti-phase then demonstration, and homophase does not then show.LCD drives and to be dual-in-line 40 pin integrated circuit TSC7211AM, and it and microcomputer bus compatibility can drive LCD demonstration four figures.The correspondent section that 28 section drive output signal of TSC7211AM meet 4002SH is selected pin, and backplane signal output 5 connects 1 and 40 pin of 4002SH, vibration input 36 pin open circuit.Data, position choosing, sheet that the AD0-AD5 of 8098 single-chip microcomputers, WR and system address gating signal Y insert TSC7211AM select input end, and the latter deciphers, latchs and drive 4002SH with the former input signal and shows.

In sum, A, B passage are worked simultaneously when powering on, but only the data of A channel can be sent demonstration.When A channel breaks down, fault identification circuit 1 will work in coordination with 8098 single-chip microcomputers and system software diagnosis, discern them, and provide signal to the fault isolation circuit, and the latter isolates A channel and LCD, and send demonstration with the data of B passage.When the B passage also breaks down, fault identification circuit 2 will be worked in coordination with 8098 single-chip microcomputers 2 and be diagnosed, discerns them with system software, and provide signal to warning circuit, carry out sound and light alarm.Realized primary fault work, secondary failure is reported to the police.

Claims

1, a kind of aircraft fuel oil tester, include power supply, sensor, microcomputer and demonstration, it is characterized in that: the two remaining tolerating measure circuit that are used for this instrument mainly are made up of two identical hardware corridors of A and B, wherein A channel is: single-chip microcomputer 8098 (1) connects RAM and fault identification circuit (1) respectively, RAM is connected the fault isolation circuit simultaneously with fault identification circuit, the fault isolation circuit connects lcd driver, and lcd driver connects LCD display; The B passage is: single-chip microcomputer 8098 (2) connects RAM and fault identification circuit (2) respectively, and fault identification circuit (2) connects reports to the police, and RAM connects the fault isolation circuit, and the fault isolation circuit connects lcd driver, and driver connects LCD display.

2, aircraft fuel oil tester according to claim 1, it is characterized in that: the monostable circuit 74LS122 that can heavily trigger, comparer LM339, rejection gate 74LS27 and phase inverter 74LS04 form, and the fault isolation circuit is made up of phase inverter 74LS04 and four analog switches 4066; Its circuit connecting relation is:

The A1 pin of 74L122 connects the reset terminal RESET of single-chip microcomputer 8098, B1, B2, CLR meets 5V simultaneously, the A2 pin connects the tie point of resistance R 1 and capacitor C 1, the other end of R1 connects 5V, the other end ground connection of C1, series resistor R2 and capacitor C 2 between 11 pin of 74LS122 and 14 pin, 13 pin connect the tie point of R2 and C2, the Q end of 74L122 connects the 3rd pin of rejection gate 74LS27, the 1st pin of phase inverter 74LS04 connects the P2.0 end of single-chip microcomputer 8098, output terminal the 2nd pin of comparer LM339 connects the 5th pin of rejection gate 74LS27, the 5th pin of LM339 connects low level V1, the 4th pin of LM339 connects supply voltage VC, the 3rd pin that the 6th pin of 74LS27 connects phase inverter 74LS04 connects analog switch 4066 (1) simultaneously, (2) E end, the 4th pin of phase inverter 74LS04 connects analog switch 4066 (3), (4) E end, analog switch 4066 (1), (2) X end connects the AD0-3 and the AD4 of single-chip microcomputer 8098 (1) respectively, 5, WR, the Y2 end, analog switch 4066 (1), (2), (3), (4) Y end connects the input end of lcd driver.