longitudinal autopilot
DESCRIPTION
longitudinal autopilots design using MATLABTRANSCRIPT
![Page 1: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/1.jpg)
0
Longitudinal Autopilots
12/11/2015
![Page 2: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/2.jpg)
1
Introduction
12/11/2015 Flight Control Systems
Autopilot uses:
For safety reasons
Lowers pilot workload (especially for long flights)
Types
Control or Hold certain flight parameter(s)
Perform navigational tasks
![Page 3: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/3.jpg)
2
Introduction
12/11/2015 Flight Control Systems
![Page 4: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/4.jpg)
3
Introduction
12/11/2015 Flight Control Systems
![Page 5: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/5.jpg)
4
Longitudinal Autopilots Pitch Hold Altitude Hold Airspeed Hold Mach Hold Climb/Descend rate Hold
12/11/2015 Flight Control Systems
![Page 6: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/6.jpg)
5
Pitch Attitude Hold Autopilot
9/10/2012
![Page 7: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/7.jpg)
6
Pitch Hold Prevents pilot having to constantly control pitch attitude in
turbulent air (e.g. TURB switch in 747-400)
Autopilot mode analysis/design, 2 important questions: Which type of control device do we use?
Elevator
What type of feedback loop structure (sensor)? Vertical gyro
12/11/2015 Flight Control Systems
![Page 8: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/8.jpg)
7
Pitch Hold Block Diagram
12/11/2015 Flight Control Systems
![Page 9: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/9.jpg)
8
Pitch Hold Block Diagram
12/11/2015 Flight Control Systems
𝐻𝐻𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔 ≈ 1
𝐻𝐻𝑠𝑠𝑠𝑠𝑔𝑔𝑠𝑠𝑔𝑔 ≈1
𝜏𝜏𝑠𝑠𝑠𝑠𝑔𝑔𝑠𝑠𝑔𝑔𝑠𝑠 + 1
𝐾𝐾(𝑠𝑠)𝐾𝐾𝑃𝑃 +𝐾𝐾𝐼𝐼𝑠𝑠
+ 𝐾𝐾𝐷𝐷𝑠𝑠𝐾𝐾𝐷𝐷𝑠𝑠2 + 𝐾𝐾𝑃𝑃𝑠𝑠 + 𝐾𝐾𝐼𝐼𝑠𝑠
![Page 10: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/10.jpg)
9
Pitch Hold Block Diagram
12/11/2015 Flight Control Systems
![Page 11: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/11.jpg)
10
Pitch Hold Example: Cessna 620
12/11/2015 Flight Control Systems
![Page 12: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/12.jpg)
11
Pitch Hold Example: Cessna 620
12/11/2015 Flight Control Systems
![Page 13: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/13.jpg)
12
Pitch Hold Example: Cessna 620 Simulink & sisotool Gain
12/11/2015 Flight Control Systems
![Page 14: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/14.jpg)
13
Pitch Hold Example: Cessna 620 𝐾𝐾 = 0.5 Short period damping goes from ζ = 0.716 to ζ = 0.464 But it still satisfies the requirements, so no inner loop
(SAS loop) is required.
12/11/2015 Flight Control Systems
![Page 15: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/15.jpg)
14
Pitch Hold Example: Cessna 620
12/11/2015 Flight Control Systems
![Page 16: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/16.jpg)
15
Pitch Hold Example: Cessna 620
12/11/2015 Flight Control Systems
![Page 17: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/17.jpg)
16
Pitch Hold Example: Boeing 747-200
12/11/2015 Flight Control Systems
![Page 18: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/18.jpg)
17
Pitch Hold Example: Boeing 747-200
12/11/2015 Flight Control Systems
![Page 19: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/19.jpg)
18
Pitch Hold Example: Boeing 747-200
12/11/2015 Flight Control Systems
![Page 20: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/20.jpg)
19
Pitch Hold Example: Boeing 747-200 Simulink & sisotool Gain
12/11/2015 Flight Control Systems
![Page 21: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/21.jpg)
20
Pitch Hold Example: Boeing 747-200
12/11/2015 Flight Control Systems
![Page 22: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/22.jpg)
21
Pitch Hold Example: Boeing 747-200
12/11/2015 Flight Control Systems
![Page 23: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/23.jpg)
22
Pitch Hold Example: Boeing 747-200
12/11/2015 Flight Control Systems
![Page 24: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/24.jpg)
23
Pitch Hold Example: Boeing 747-200
12/11/2015 Flight Control Systems
![Page 25: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/25.jpg)
24
Pitch Hold Example: Boeing 747-200
12/11/2015 Flight Control Systems
![Page 26: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/26.jpg)
25
Pitch Hold
12/11/2015 Flight Control Systems
![Page 27: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/27.jpg)
26
Pitch Hold
12/11/2015 Flight Control Systems
![Page 28: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/28.jpg)
27
Pitch Hold
12/11/2015 Flight Control Systems
![Page 29: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/29.jpg)
28
Pitch Hold
12/11/2015 Flight Control Systems
Flight Conditions
![Page 30: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/30.jpg)
29
Pitch Hold
12/11/2015 Flight Control Systems
Flight Conditions
![Page 31: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/31.jpg)
30
Pitch Hold
12/11/2015 Flight Control Systems
![Page 32: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/32.jpg)
31
Pitch Hold
12/11/2015 Flight Control Systems
![Page 33: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/33.jpg)
32
Pitch Hold
12/11/2015 Flight Control Systems
![Page 34: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/34.jpg)
33
Pitch Hold
12/11/2015 Flight Control Systems
![Page 35: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/35.jpg)
34
Altitude Hold Autopilot
9/10/2012
![Page 36: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/36.jpg)
35
Altitude Hold Prevents pilot having to constantly control altitude during
the flight
Autopilot mode analysis/design, 2 important questions: Which type of control device do we use?
Elevator
What type of feedback loop structure (sensor)? Altimeter
12/11/2015 Flight Control Systems
![Page 37: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/37.jpg)
36
Altitude Hold
12/11/2015 Flight Control Systems
![Page 38: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/38.jpg)
37
Altitude Hold
12/11/2015 Flight Control Systems
![Page 39: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/39.jpg)
38
Altitude Hold
12/11/2015 Flight Control Systems
![Page 40: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/40.jpg)
39
Altitude Hold
12/11/2015 Flight Control Systems
![Page 41: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/41.jpg)
40
Altitude Hold
12/11/2015 Flight Control Systems
![Page 42: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/42.jpg)
41
Altitude Hold
12/11/2015 Flight Control Systems
![Page 43: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/43.jpg)
42
Altitude Hold
12/11/2015 Flight Control Systems
![Page 44: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/44.jpg)
43
Altitude Hold
12/11/2015 Flight Control Systems
![Page 45: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/45.jpg)
44
Altitude Hold
12/11/2015 Flight Control Systems
![Page 46: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/46.jpg)
45
Altitude Hold
12/11/2015 Flight Control Systems
![Page 47: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/47.jpg)
46
Altitude Hold
12/11/2015 Flight Control Systems
![Page 48: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/48.jpg)
47
Airspeed Hold Autopilot
9/10/2012
![Page 49: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/49.jpg)
48
Airspeed Hold Prevents pilot having to constantly control airspeed
during the flight
Autopilot mode analysis/design, 2 important questions: Which type of control device do we use?
Throttle
What type of feedback loop structure (sensor)? Airspeed Sensor
12/11/2015 Flight Control Systems
![Page 50: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/50.jpg)
49
Airspeed Hold
12/11/2015 Flight Control Systems
![Page 51: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/51.jpg)
50
Airspeed Hold
12/11/2015 Flight Control Systems
![Page 52: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/52.jpg)
51
Airspeed Hold
12/11/2015 Flight Control Systems
![Page 53: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/53.jpg)
52
Airspeed Hold
12/11/2015 Flight Control Systems
![Page 54: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/54.jpg)
53
Airspeed Hold
12/11/2015 Flight Control Systems
![Page 55: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/55.jpg)
54
Flight Path Angle Hold Or Climb/Descent Rate Hold Autopilot
9/10/2012
![Page 56: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/56.jpg)
55
Flight Path Angle Hold Prevents pilot having to constantly control airspeed
during the flight
Autopilot mode analysis/design, 2 important questions: Which type of control device do we use?
Elevator
What type of feedback loop structure (sensor)? Flight Path Angle??
It is not directly measureable so vertical gyro and angle of attack sensor are used.
12/11/2015 Flight Control Systems
![Page 57: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/57.jpg)
56
Flight Path Angle Hold
12/11/2015 Flight Control Systems
![Page 58: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/58.jpg)
57
Flight Path Angle Hold
12/11/2015 Flight Control Systems
![Page 59: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/59.jpg)
58
Flight Path Angle Hold
12/11/2015 Flight Control Systems
![Page 60: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/60.jpg)
59
Flight Path Angle Hold
12/11/2015 Flight Control Systems
![Page 61: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/61.jpg)
60
Summary For each Hold autopilot there are two important
questions: Which type of control device? Which type of feedback? loop structure? sensors?
Keep controller as simple as possible Proportional only (if acceptable) PD, PI, Lead/Lag, etc…
The closed loop system must comply with the airworthiness requirements
12/11/2015 Flight Control Systems
![Page 62: Longitudinal Autopilot](https://reader035.vdocuments.site/reader035/viewer/2022082202/5695d0611a28ab9b02924133/html5/thumbnails/62.jpg)
61
Summary Take into account the inner loop, when constructing the
outer loop. Keep in mind the possible effects on the closed loop
system of: Servo break frequency Flight condition (airspeed, altitude) etc...
12/11/2015 Flight Control Systems