ee6900 flight management systems · 2018. 4. 22. · ee6900 flight management systems “flight...

EE6900 Flight Management Systems

“Flight Deck Systems – Part 1”

Dr. Maarten Uijt de Haag

Ohio University

Boeing 737NG

2

Boeing 737NG Flight Deck

3

B737 Flight Deck

4

B737 Display Units/Panels

5From: B737-700/800, Flight Crew Operations Manual

B737 Display Units

6From: B737-700/800, Flight Crew Operations Manual

Multifunction Display

(MFD)

Forward Electronic Panel

Control Display Unit

(CDU)

Main interface with Flight

Management System

B737 Display Units

7From: B737-700/800, Flight Crew Operations Manual

Captain

Primary Flight Display

(PFD)

Captain

Navigation Display

(ND)

First Officer

Primary Flight Display

(PFD)

First Officer

Navigation Display

(ND)

Upper

Display

Unit

Lower

Display

UnitCaptain

Control Display Unit

(CDU)

First Officer

Control Display Unit

(CDU)

Information Reference Frames

• Inertial frame

• Earth frame

• Navigation frame

• Body frame

• Geographic

• Etc.

8

Inertial Reference Frames

9

• True inertial:

– the frame does not accelerate (rotate) w.r.t. the fixed stars

– only frame in which Newton’s laws are valid (non-relativistic)

• Earth Centered Inertial (ECI) or i-frame:

– at the start of navigation the

• z-axis is aligned with the earth’s spin axis (Polaris)

• x,y-plane is the equatorial plane

• x-axis points to a fixed star called “the first point in Aries”

(or Vernal Equinox); thus the axes are centered in the

earth but they do not rotate with the earth

ECI – i-frame

10

ECEF Frame

11

• Earth-Centered Earth-Fixed (ECEF) or e-frame:

– rotates with the earth (in GPS-parlance, this is known as

ECEF coordinates)

– x-axis aligned with prime meridian (Greenwich)

Greenwich

meridian

ex ey

ei z,z

Pole

ie

ix

iy

Navigation Frame• Navigation frame (NED) or n-frame

– origin within INS, local-level frame

– +z-axis “down (D),” direction of gravity vector

– +x-axis points north (N), + y-axis points east (E)

12

ex ey

ei z,z

ie

ix

iy

R

h

N

ED

NED Up-close ……….

13

ex ey

ei z,z

ie

ix

iy

R

h

N

ED

Body Frame – Attitude and Yaw

14

• The body-frame (b-frame) has its origin at

vehicle center of mass– Often principal body axes

• Aircraft convention:– + x-axis is longitudinal (roll) axis (out nose)

– + y-axis is lateral (pitch) axis (out right wing)

– + z-axis is down (yaw axis)

– Why not pick z to be up instead? The axes are

chosen such that positive rotations produce positive

Euler angles (pitch, roll, yaw)

Body Frame (rigidly attached to aircraft)

15

x

z

y

*Courtesy of NASA (Flight over Lake Tahoe, GVSITE 2004)

Right Hand Rule

16

x-axisy-axis

z-axis

Geographic Frame

17

N

ED

navigation frame /

local geographic frame

L

Longitude

L Latitude

Transformations – No Wind

18

Navigation

Frame

Body

Frame

“Wind”

Axes

Velocity

Axes

𝐂𝑛𝑏 = 𝐂𝑥(𝜙)𝐂𝑦(𝜃) 𝐂𝑧(𝜓)

𝐯𝑏 =𝑢𝑣𝑤

= 𝐂𝑛𝑏𝐯𝑛

𝐯𝑛 =

𝑣𝑛𝑣𝑒𝑣𝑑

𝐂𝑎𝑏 = 𝐂𝑦(𝛼) 𝐂𝑧(−𝛽)

Euler angles

(roll, pitch, yaw)

Airflow angles

(angle of attack, sideslip angle)𝐯𝑎

𝐂𝑣𝑎 = 𝐂𝑥(𝜇)

Bank angle

𝐂𝑛𝑣 = 𝐂𝑦(𝛾) 𝐂𝑧(𝜉)

Velocity angles

(flight path angle, track)

𝐯

X axis is aligned with aircraft

centerline (pointing out of the nose)

X axis is aligned with

true north

X axis is aligned with

velocity vector

rotation around

velocity vectorRoll angle: rotation around

aircraft centerline

Where …

19

𝐂𝑥 𝑏 =1 0 00 cos 𝑏 sin 𝑏0 − sin 𝑏 cos 𝑏

,

𝐂𝑦 (𝑏) =cos(𝑏) 0 −sin(𝑏)0 1 0

sin(𝑏) 0 cos(𝑏), 𝐂𝑧 (𝑏) =

cos(𝑏) sin(𝑏) 0−sin(𝑏) cos(𝑏) 0

0 0 1

Information Geometry

20

True

North

𝜓

Aircraft center line

(body x-axis)

East

Aircraft right wing

(body y-axis)

z-axis is pointing into the paper

21

True

North

𝜓

𝐯 = 𝐯𝒆

𝛽

East

Aircraft center line

(body x-axis)

Aircraft right wing

(body y-axis)

𝜉

Information Geometry – No Wind

22

True

North

𝜓

𝐯𝛽

East

Aircraft center line

(body x-axis)

Aircraft right wing

(body y-axis)

𝜉

Information Geometry – Add Wind

𝐯𝑒

𝐯𝑤

𝐯

𝐯𝑒

Air-relative velocity (airspeed)

Earth-relative velocity

𝐯𝑤 Wind velocity

𝛿 Drift angle

𝛿

23

True

North

𝜓

𝐯𝛽

East

Aircraft center line

(body x-axis)

Aircraft right wing

(body y-axis)

𝜉

Information Geometry – Add Wind

𝐯𝒆

𝐯𝑤

𝐯

𝐯𝒆

Air-relative velocity (airspeed)

Earth-relative velocity

𝐯𝑤 Wind velocity

𝛿 Drift angle

True

North

−𝐯𝑤

𝑤𝑎𝑤𝑑

wind angle

wind direction 𝐯𝑤

𝛿

𝜃

Information Geometry – Side-View

24

Aircraft center line

(body x-axis)

Down

(body z-axis)

North-East plane

Body y-axis is coming out of the paper

𝛾𝜃

Information Geometry – No Wind

25

Aircraft center line

(body x-axis)

Down

(body z-axis)

𝛼𝐯

North-East plane

Body y-axis is coming out of the paper

𝛾𝜃

Information Geometry – Add Wind

26

Aircraft center line

(body x-axis)

North-East plane

Down

(body z-axis)

𝛼𝐯 𝐯𝑤

𝐯𝑒

Body y-axis is coming out of the paper

𝛾𝜃

Information Geometry – Add Wind

27

Aircraft center line

(body x-axis)

North-East plane

Down

(body z-axis)

𝛼𝐯 𝐯𝑤

𝐯𝑒

Body y-axis is coming out of the paper

𝛾𝑒

Earth referenced flight path angle

Air mass referenced flight path angle

𝛾𝜃

Information Geometry – Add Wind

28

Aircraft center line

(body x-axis)

North-East plane

Down

(body z-axis)

𝛼𝐯 𝐯𝑤

𝐯𝑒

Groundspeed

(horizontal component)

𝐯𝑔

Furthermore: Airspeed: 𝑉 = 𝐯

Groundspeed: 𝑉𝒈 = 𝐯𝒈

29

True

North

𝜓

𝐯

East

Aircraft center line

(body x-axis)

𝜉

Information Geometry – Math

𝐯𝒆𝛿

𝐯𝑛 =

𝑣𝑛𝑣𝑒𝑣𝑑

=

𝑉𝑔𝑐𝑜𝑠 𝜓 + 𝛿

𝑉𝑔𝑠𝑖𝑛 𝜓 + 𝛿𝑣𝑒,3

Note: 𝜓 + 𝛿 = 𝜉

𝛽

Information Geometry – Math

30

True

North

𝜓

𝐯𝛽

East

𝜉

𝐯𝒆

𝐯𝑤

Aircraft center line

(body x-axis)

𝐯𝑛 = 𝐯 + 𝐯𝑤 =

𝑉𝑐𝑜𝑠 𝜃 − 𝛼 𝑐𝑜𝑠 𝜓 + 𝛽

𝑉𝑐𝑜𝑠 𝜃 − 𝛼 𝑠𝑖𝑛 𝜓 + 𝛽

𝑉𝑠𝑖𝑛 𝜃 − 𝛼

+

𝑣𝑤,𝑛𝑣𝑤,𝑒𝑣𝑤,𝑑

Note: 𝜃 − 𝛼 = 𝛾

𝛿

Primary Flight Display

31

Near term,

tactical information

Primary Flight Display

32

Flight mode

annunciator

Airspeed/Mach

indicator

Attitude indications

Altitude indications

Vertical speed

indications

Heading/track

indications

Autopilot/flight

director status

𝑉 = 𝐯

Airspeed Tape

33

Selected speed

Speed trend vector

Calibrated airspeed

Maximum operating speed

Maximum operating speed

Speed bug (see selected speed)

Current Mach

For takeoff and approach additional symbology is used: more on that later.

Predicted airspeed

in the next 10

seconds; based on

current airspeed

and acceleration

𝑉 and 𝑑𝑉

𝑑𝑡

Speeds in kts

Altitude Tape

34

Selected altitude bug

Selected altitude

Current altitude in feet (ft)

ℎ𝑏𝑎𝑟𝑜

Current altitude in meter

(if selected on EFIS control panel)

Selected altitude in meters

Pressure in hectopascal (more later)

Attitude

35

Bank scale(marks at 0, 10, 20, 30,

45 and 60 degrees)

Pitch limit indication(at this point the stick shaker

would be activated)

Flight Director Bar(steering commands)

Horizon line(zero degrees pitch)

Pitch scale/ladder(2.5 degree increments)

Flight Path Vector (FPV)

Bank pointer

Slip indicator

Airplane symbol

Flight Path Angle wrt horizon line

Drift angle wrt display center

Attitude

36

Bank scale(marks at 0, 10, 20, 30,

45 and 60 degrees)

Pitch limit indication(at this point the stick shaker

would be activated)

Flight Director Bar(steering commands)

Horizon line(zero degrees pitch)

Pitch scale/ladder(2.5 degree increments)

Flight Path Vector

Bank pointer

Slip indicator

Airplane symbol

Flight Path Angle wrt horizon line

Drift angle wrt display center(crosshair version)

Heading and Track

37

Current heading(black triangle)

Current track

Selected heading

(digital)

Selected heading

MAG: heading wrt magnetic North

TRU: heading wrt true North

Navigation Display

38

Strategic information

Navigation Display

39

Groundspeed and

True Airspeed

Wind Direction/Speed

and Arrow

Weather

Range scale and track line

Airplane symbol

Map source

VORTAC symbol

Navigation Display

40

Active waypoint/ETA/

Distance-to-go

Active LNAV route

Position trend vector

Vertical deviation scale and

pointer

Compass Rose

Selected Heading bug

Vertical Situation Display (VSD)

41

Selected altitude bug

Baro minimum

Selected altitude (ft)

Waypoint ID (plus

optional altitude

constraint)

B787 Display Units

42From: B787, Flight Crew Operations Manual

Left side:

Primary Flight Display

(PFD)

Multifunction Display

(MFD)

B787 Display Units

43

B787 vs B737

44

B787 – Navigation Display

• Multiple variations of the ND exist even on one

aircraft:

– Map Mode

• Presented track-up: shows airplane position relative to the

route of flight against a moving map background;

• Recommended for most phases flight.

– Plan Mode

• Presented true North up.

45

B787 – Navigation Display

46

Expanded

Map Mode:

B787 – Navigation Display

47

Centered

Map Mode:

B787 – Navigation Display

48

Expanded

Map Mode

+ Weather:

B787 – Navigation Display

49

Plan Mode:

Head Up Display (HUD)

50

In a head up display system

flight data symbology is

projected onto a transparent

glass “combiner”: screen in the

pilot’s forward field of view.

This allows the pilot to see the

data while looking through the

forward windscreen.

The optics in head-up display

systems are used to “collimate”

the HUD image so that

essential flight parameters,

navigational information, and

guidance are superimposed on

the outside world scene.

Head Up Display (HUD)

51

B737 ExampleB787 Example

Head Up Display

52

Same symbology as on head-down PFD, just projected

on combiner glass in green.

Head Up Display

53From: C. Spitzer, The Avionics Handbook, Chapter 4 by R. Wood and P. Howells

Head Up Displays

54From: C. Spitzer, The Avionics Handbook, Chapter 4 by R. Wood and P. Howells

Reflective Type HUD

Collimation of the light causes parallel light rays, causing the lens of the human eye to

focus on infinity to get a clear image. Collimated images on the HUD combiner are

perceived as existing at or near optical infinity. This means that the pilot's eyes do not

need to refocus to view the outside world and the HUD display.

HUD Field of View (FOV)

55From: C. Spitzer, The Avionics Handbook, Chapter 4 by R. Wood and P. Howells

HUD - Other Considerations

• Luminance/contrast – Displays have adjustments in

luminance and contrast to account for ambient lighting,

which can vary widely

• Boresighting: – the accurate alignment of the HUD

components with the three axes of the aircraft. This way,

objects projected on the combiner and actual visual

align. Example accuracy: ±7.0 milliradians.

56

Synthetic Vision System (SVS)

57

Besides the normal primary flight symbology, visualize additional information such

as a synthesized version of the “outside world”

Synthetic Vision System (SVS)

58

B737B787 SVS

Examples

Examples

Why Synthetic Vision?• Often quoted reasons:

– Compensate for the lack of direct visibility

– Provide better visibility than is possible with the out-of-the-

window view

– Intuitively depict non-physical constraints and threats

• Expected results:

– Improved terrain awareness

– Improved conflict/threat awareness

– Increase in safety and operational capabilities

• SV is seen as an enabler in various CONOPS, both civil

and military

– Functional requirements differ between CONOPS

– The requirements drive the design!

61

Classification using 3 layers

• Top layer: Primary Flight Information

• Intermediate layer: Guidance preview

• Background layer: Awareness (terrain, obstacles, threats, conflicts)

SVS – Visualizing Constraints• Static non-physical constraints:

– Restricted airspace

– Threat volumes

• Dynamic non-physical

constraints:

– Space where loss of separation

with other traffic would occur if

maneuvering in that direction

63

• Converted into 3-D object

• Rendered in the background layer

Realism: Photo-textures

• Sources

– Aerial photography

• Very realistic synthetic

environment

• Issues:

– Never the real thing, e.g. due to

seasonal effects

– May weaken terrain shape cues

as compared to regular patterns

– Uncontrolled cue type and

strength

Enhanced Vision System (EVS)

• Use information from aircraft based sensors (e.g., near-infrared

cameras, millimeter wave radar) to provide vision in limited visibility

environments.

• Can be visualized as a raster image on the HUD (or on HDD).

• Aircraft equipped with certified EVS are allowed Category I

approaches to Category II minimums.

65

See: http://article.wn.com/view/2013/10/11/Rockwell_Collins_Unveils_New_EVS3000_Enhanced_Vision_System/#/video

Rockwell-Collins EVS-3000

Information Requirements

• Information is provided by various avionics

“boxes”

– Air Data Computer (ADC or ADRS)

– Inertial Reference System (IRS or ARU)

– Global Navigation Satellite System (GNSSS)

– Distance Measuring Equipment (DME)

– VHF Omnidirectional Range (VOR)

– Radio (Radar) Altimeter (RADALT)

– Flight Management System (FMS)• Does some “sensor integration”

– Data Links

– Multifunction Control Display Unit (MCDU)• Human input

– Flight Control Computer (FCC)

– Thrust Control Computer (TCC)

66More on those in the “Avionics Summary”

Information Sources – Air Data

67For example: ARINC706 – Digital Air Data System

Information Sources - Inertial

68For example: ARINC704 – Inertial Reference System

Typically the IRS is connected to ADC.

Information Sources - Inertial

69Attitude: roll and pitch

Information Sources - GNSS

70For example: ARINC743B

Information Sources - GNSS

71For example: ARINC743B

Information Sources

72

Fault Tolerance

Flight Deck …. Behind the Scenes

73

FMC#1

FMC#2

FCC#1

FCC#2

MCDU “A”

MCDU “A”

CAPTEFI

CAPTEFI CTLR

FOEFI

FOEFI CTLR

FCCSCTRLR

GNSS#1

IRU#1

ILS#1

ADC#1

VOR#1

DME#1

TCCIRU#3

VOR#2

ILS#2

DME#2

IRU#2

ADC#2

GNSS#2

ACARSCMU #1

PropulsionData

Engine-Indicating and Crew-Alerting System (EICAS)

74

B787 EICAS

A380 Display Units …

75