CN1027800C

CN1027800C - Stall warning system

Info

Publication number: CN1027800C
Application number: CN 92110416
Authority: CN
Inventors: 欧瑞林; 谢葱茏; 田鹏良
Original assignee: Taihang Instrument Factory Ministry Of Aerospace Industry
Current assignee: Taihang Instrument Factory Ministry Of Aerospace Industry
Priority date: 1992-09-10
Filing date: 1992-09-10
Publication date: 1995-03-08
Anticipated expiration: 2007-09-10
Also published as: CN1069946A

Abstract

The invention relates to an aircraft stall warning system. The aircraft is characterized in that flight state signals obtained by an M sensor and an attack angle sensor are used for calculating values of an attack angle and a critical angle of an aircraft through a single chip microcomputer, then digital signals are used for directly driving a motor of an attack angle and critical angle combined indicator to rotate through an attack angle passage and a critical angle passage respectively, a stepping motor drives a speed reducer and a speed increaser to convert the calculated values into angle quantities and inform a pilot of the current condition of the aircraft flight, and the condition that stall warning is sent only by using signals such as light, sound and jitter in the past is changed.

Description

Stalling alarm system

The present invention relates to a kind of aircraft stall warning system.

Aircraft take off, land, during cruising flight, whether the take-off angle of attack of aircraft and the current state of flying speed normal, this is that the aviator needs to grasp at any time, when abnormal condition appear in aircraft, should be able to make the aviator in time obtain warning, is revised.In the stall-warning system of numerous type passenger planes, (as Boeing-747,757, DC-10, MD-81/87, the A300-B2/B4 aircraft of the U.S., amp-26 aircrafts of the former Soviet Union, the BA.146-100 aircraft of Britain etc.), all be by aircraft critical angle of attack sensor mostly, angle of attack sensor, signal and setting signal contrasts such as flap configuration, whether normally draw flight signal, and use light, forms such as sound equipment, stick shaker are warned the aviator.And the signal conditioning of these warning systems is resolved algorithm because of different aircrafts has different stall, Boeing 757,767 aircraft stall warning systems are handled the angle of attack signal of input by the stall assembly that is inserted in the central warning system, when stall takes place, send light by central warning system, warning signals such as sound equipment, simultaneously, excitation stick shaker device shake.When aircraft still was in stall condition after 2 seconds, push rod changed stall.And pacify 26 aircraft stall warning systems is to drive the angle of attack and critical angle pointer by the traditional electromechanical follow-up system of two covers, and cam is housed on one of them pointer, on another pointer switch is housed.When two pointers coincide, switch provides the stall warning signal, this system does not have indicating device, US Airways and space administration are to be the digital system of treater with 8085CPU for the stall-warning system of OV-IC aircraft development, it utilizes dynamic pressure and static pressure to calculate true air speed, utilize signals such as flap configuration, elevating rudder position, acceleration/accel to calculate stalling speed, and then convert digital signal to analog signal, carry out the conversion driving indicating device with synchro.When true air speed during near stalling speed, send stall warning, various stall-warning systems in sum, they all respectively have the not place of person of modern times's meaning, the stall warning signal of the stall-warning system of Boeing series and former Soviet Union peace series aircraft all sends by modes such as stick shaker, light, the aviator can't know that aircraft is apart from the present case of stall condition and variation tendency with answer correction, though and the stall-warning system of OV-IC aircraft has indicating device, but, because of it has a signal conversion process, what indicating device provided is flying speed, and signal aspect and indication has a delay.

The objective of the invention is, the aviator can be to there being a direct quantity notion before and after the aircraft stall, can find out directly that aircraft (comprised normal flight) before stall and stall after the situation of change of (after the stall warning), thereby avoid aircraft to enter stall condition, the aviator can be flown with optimum angle of attack and speed.

Technical solution of the present invention is: the state of flight signal of counting sensor and angle of attack sensor with M, is digital signal through multiple way switch, sample/hold circuit and analog to digital conversion circuit with analog signal conversion, calculate aircraft angle of attack and critical angle by micro controller system again, drive the interconnecting device on the angle of attack, critical angle group indicater and the aircraft, send the aircraft stall warning signal.

The present invention has changed the defective of no indicating device in the prior art, it uses digital signal direct drive indicating device, make indicating device directly indicate aircraft angle of attack and critical angle, system performance has obtained big improvement, allow the aviator to a direct quantity notion is arranged before and after the aircraft stall, and the timely round-off error of energy, with optimum angle of attack and speed flight.

Accompanying drawing provides system principle diagram

M counts the d. c. voltage signal of sensor (1), angle of attack sensor (2) input and mode voltage (10.24V) and earth signal and adds multi-way switch circuit (3) together, after finishing conversion to multi-analog, be input to sample/hold circuit (4), finish sampling/maintenance and amplification analog quantity on duty.This signal adds to A and D converter (5), finishes the A/D(modulus of analog quantity on duty) conversion.Then, be input to interface chip (6), its function is:

The a.A mouth links to each other with 12 position datawires of A and D converter (5), is A/D quantitative data input path;

The b.B mouth is finished multi-way switch circuit (3), the logic control of sample/hold circuit (4), A/D circuit (5).

The c.C mouth is finished the input of each switching value.

D. also have the read functions of system's multi-section concurrently.

Micro controller system (7) is by the B mouth control multiple way switch (3) of chip (6), finish input by turns to 4 analog quantitys, control is adopted/is protected circuit (4) and the analog quantity of being imported is sampled and keeps, control A/D converter (5) is finished analogue to digital conversion, and data are read in micro controller system (7) by interface chip (6), micro controller system (7) calculates the analog quantity of input, and its function is:

A. the 10.24V mode voltage is monitored, when the voltage error of ± 20mv, send failure warning.

B. the mould ground voltage is monitored, when the voltage error of ± 20mv, send failure warning.

C. the magnitude of voltage as prescribed that M is counted sensor (1) is calculated by line, obtains the aircraft critical angle.

D. the magnitude of voltage as prescribed curve of the local angle of attack sensor of aircraft (2) is calculated, obtain aircraft angle of attack.

E. the aircraft critical angle and the angle of attack are compared calculating, when aircraft angle of attack is equal to or greater than the critical angle value, send stall warning.

F. micro controller system (7) calculates corresponding pulse equivalency according to aircraft angle of attack and critical angle value, and aircraft angle of attack and the critical angle pointer controlling simultaneously and drive in the angle of attack, the critical angle group indicater (I) are indicated corresponding angle value.

G. when interrupting, judge and carries out accordingly and operate according to detection, zero-bit in chip (6) the c mouth.

Output signal after micro controller system (7) calculates, the R/G on one tunnel control aircraft in the interconnecting device sends warning signals such as stall light, sound equipment stick shaker, and the indicating device drive control signal is sent on another road.This signal divides two-way to import angle of attack path (II) and critical angle path (III) respectively again.Aircraft critical angle path (III) is identical with the composition of angle of attack path (II).Now only to aircraft angle of attack path (II) explanation.The signals reverse that NAND gate (8) is come micro controller system (7), NAND gate (9), (10), it is reverse that joint denial gate (11) is formed zero-bit, forbids logic and pulse gate.Photoelectric isolating circuit (12) is finished the isolation of monolithic (7) part and drive part, to improve system's antijamming capability.The signal of isolating output is after shaping circuit (13) shaping, pulse distributor (14) converts the signal after the shaping to stepping motor (M) required three-phase pulse signal, carry out the modulation of 15～30KHz through modulator (15), promote the Darlington aerotron through current-limiting resistance and carry out power gain, feed three phase windings of stepping motor in the angle of attack, critical angle group indicater (I), drive motor is done corresponding rotation, finish digital quantity to angle metric conversion with this, diode is finished the afterflow effect.

The angular metric of motor is through retarder i ₁Drive pointer and be indicated on the corresponding aircraft angle of attack value, meanwhile, speed increaser i ₂Drive the grating circuit parts, the impulse singla that output is directly proportional with the motor rotational angle, and this value is given the T of micro controller system (7) through switch.Count.Interrupt when this value equates with computing value, carry out interrupt handling, control joint denial gate (11) is closed, and lock is lived the adding of pulse, promptly stops the rotation of motor, thereby forms closed-loop digital formula follow-up system.Null pick-up (16) in the indicating device (I) is a calibration follow-up system position reference when system works is initial, electric spacing when being used for zero-bit of the NAND gate in the drive plate (9), (10).

In addition, impulse deviser (17) is the omnibus circuit of aircraft angle of attack path and critical angle path, and when system breaks down or power supply when fault is arranged, micro controller system (7) has signal that failure flag is fallen, and reminds the aviator system that fault is arranged.This stall-warning system also has detection, functions such as supervision.Latch (18) is finished micro controller system reading external program.

Claims

1, by the aircraft angle of attack sensor, M counts sensor, stall and resolves the stall-warning system that computing machine, electromechanical follow-up system are formed, it is characterized in that, multiple way switch is counted sensor with M, being input to sample/hold circuit after the voltage signal of angle of attack sensor input and mode voltage and the earth signal conversion amplifies, add A and D converter then, after interface chip read, the adding micro controller system carried out numeral and resolves.

2, stall-warning system according to claim 1 is characterized in that: the angle of attack of calculating through the micro controller system digital solution and the digital signal of critical angle, control and drive the angle of attack, critical angle group indicater simultaneously, and the control warning system is sent light sound equipment stick shaker signal.

3, stall-warning system according to claim 2 is characterized in that, retarder of the driven by motor of indicating device and a speed increaser, and retarder drives pointer and rotates, and speed increaser drives grating assembly.

4, stall-warning system according to claim 2 is characterized in that, the digital signal utilization of micro controller system and non-, NOR logic are formed zero-bit oppositely and spacing.