-aircraft-avionics2 -pitch angel & side siliping

8/2/2019 -Aircraft-Avionics2 -Pitch Angel & Side Siliping

1/26

AIRCRAFT AVIONICSAIRCRAFT AVIONICSPRINCIPLEPRINCIPLE

Zhang Fuchun

Dec 2006


2/26

CHAPTER 2CHAPTER 2Measuring of Aircrafts AttitudeMeasuring of Aircrafts Attitude

Measuring of Pitch Angle

and Bank Angle

Measuring of Turn andSideslip


3/26

Section 1Section 1

Measuring of Pitch Angle andMeasuring of Pitch Angle and

Bank AngleBank Angle

1. Definitions of pitch angle and bank angle


4/26

Section 1Section 1



1. Definitions of pitch angle and bank angle

A pitch angle is the included angle betweenlongitudinal axis of the aircraft and horizontalplane.

it is the included angle between symmetricplane and vertical plane on longitudinal axis ofthe aircraft.

Pitch angle:

Bank angle:


5/26

Section 1Section 1


Bank AngleBank Angle2. Basic conditions to measure pitch angle

and bank angleAltitude angles are in fact the relative location

between aircrafts vertical axis and local verticalline. If only an artificial vertical line (artificial lateral

system of coordinates) is found in aircrafts, andcompares it with airframe system of coordinates,we can measure altitude angles.


6/26

Section 1Section 1


Bank AngleBank Angle3. Basic principle of measuring pitch angle

and bank angle(1) How to simulate vertical line


7/26

3. Basic principle of measuring pitch angle

and bank angle

(1) How to simulate vertical line

To simulate vertical line by pendulum


8/26


and bank angle


To simulate vertical line by pendulum


9/26


and bank angle


To simulate vertical line by rate gyroscope


10/26


and bank angle

(2) How to simulate vertical line correctly

To take the advantage of gyros directional stability of

acceleration resistance and the gyro as the foundation of the

working of instruments; to take the advantage of the nature ofvertical to correct the gyro and make autorotation axis trace

gyros vertical line continuously. The gyro can not only

eliminate error of autorotation axiss shift from vertical line

because of wandering, but also resist interference of

acceleration. Therefore, no matter the aircraft is in level

flight or there is acceleration, autorotation axis of gyro can

simulate

vertical line accurately.


11/26


and bank angle


Composition of correction system

a. Rate gyroscope

b. Liquid pendulum

c. Correction motor


12/26


and bank angle


Error situation analysis

a. Acceleration error

b. Longitudinal acceleration error

c. Banking turn error


13/26


and bank angle

(3) Bracket servo system

Function

Control the outer frame axis of gyro andmake it vertical to autorotation axis when bankangle is arbitrary value. In this way the gyro

can maintain good stability to guarantee thedirection of artificial vertical line not beinginterfered by aircrafts attitude.


14/26


and bank angle


Composition

a. Rate gyroscope

b. Liquid pendulum

c. Correction motor


15/26


and bank angle


Composition


16/26


Working situation


17/26

Section 1Section 1



4. Indication of pitch angle and bank angle

(1) Inside-out display


18/26

Section 1Section 1




(2) Outside-in display


19/26

Section 1Section 1




(3) Basic Working principle of outside-in display


20/26

Section 1Section 1




(3) Basic Working principle of outside-in display


21/26

Section 2Section 2

Measuring of Turn and SideslipMeasuring of Turn and Sideslip1. Basic principle of measuring turns(1) Measuring the turning direction


22/26

Section 2Section 2

Measuring of Turn and SideslipMeasuring of Turn and Sideslip1. Basic principle of measuring turns(1) Measuring the turning direction


23/26

Section 2Section 2

Measuring of Turn and SideslipMeasuring of Turn and Sideslip1. Basic principle of measuring turns(2) Why does the turn indicator can indicate the

aircrafts bank angle when the aircraft is innon-sideslip turning at a certain true speed?


24/26

Section 2Section 2

Measuring of Turn and SideslipMeasuring of Turn and Sideslip1. Basic principle of measuring turns(2) Why does the turn indicator can indicate the

aircrafts bank angle when the aircraft is innon-sideslip turning at a certain true speed?

G tgv

=


25/26

Section 2Section 2

Measuring of Turn and SideslipMeasuring of Turn and Sideslip2. Basic principle of measuring sideslip(1) Working condition of the bank indicator in level flight


26/26

Section 2Section 2

Measuring of Turn and SideslipMeasuring of Turn and Sideslip2. Basic principle of measuring sideslip(2) Basic working condition of the bank indicator when the

aircraft is turning

-aircraft-avionics2 -pitch angel & side siliping

Documents