Aerospace and Electronic Systems Magazine April 2018 - 8

Navigation and Control Architecture for Launch Vehicles

Figure 2.

Figure 3.

were of different levels of complexity, including a half-sine
wave (Figure 2), a full-sine wave (Figure 3), a biased sine wave
(Figure 4), an up and down ramp (Figure 5), and a biased square
wave (Figure 6).
In all cases, the initial attitude of the launch vehicle was 0°. In
the case of the up and down ramp, where the reference trajectory
stayed at 0° for a short time, the system was able to track it closely
with hardly any deviation. In the other cases, where the reference
trajectory deviated from 0° almost immediately, whereby the initial attitude could be thought of as a perturbation from the desired
trajectory, the system was able to match up to the reference trajectory within approximately a half-second. Subsequently, it maintained the reference match closely, with only some deviation at the
discontinuities in the square wave trajectory.

Aside from determining whether the system was able to match
the reference trajectory, it was necessary to make sure that it could
do so in real time. To verify this, timing information was captured during the simulations, a typical set of which is displayed
in Figure 7. Each horizontal bar represents the total time of one
control cycle, which is broken into how much is used for forward
integration, backward integration, and control implementation and
the amount of time left over in the cycle that is not used for computation. Specifically, as long as there is appreciable leftover time
in a given cycle, the system would qualify as real time.
It is assumed that current sensor readings and actuator implementation would be handled by separate subsystems on the launch
vehicle; therefore, little additional control system time would be
consumed by these functions. This is not to say that sensor read-

Results of real-time NRHC of a half-sine wave.

8

Results of real-time NRHC of a full-sine wave.

IEEE A&E SYSTEMS MAGAZINE

APRIL 2018



Table of Contents for the Digital Edition of Aerospace and Electronic Systems Magazine April 2018

No label
Aerospace and Electronic Systems Magazine April 2018 - No label
Aerospace and Electronic Systems Magazine April 2018 - Cover2
Aerospace and Electronic Systems Magazine April 2018 - 1
Aerospace and Electronic Systems Magazine April 2018 - 2
Aerospace and Electronic Systems Magazine April 2018 - 3
Aerospace and Electronic Systems Magazine April 2018 - 4
Aerospace and Electronic Systems Magazine April 2018 - 5
Aerospace and Electronic Systems Magazine April 2018 - 6
Aerospace and Electronic Systems Magazine April 2018 - 7
Aerospace and Electronic Systems Magazine April 2018 - 8
Aerospace and Electronic Systems Magazine April 2018 - 9
Aerospace and Electronic Systems Magazine April 2018 - 10
Aerospace and Electronic Systems Magazine April 2018 - 11
Aerospace and Electronic Systems Magazine April 2018 - 12
Aerospace and Electronic Systems Magazine April 2018 - 13
Aerospace and Electronic Systems Magazine April 2018 - 14
Aerospace and Electronic Systems Magazine April 2018 - 15
Aerospace and Electronic Systems Magazine April 2018 - 16
Aerospace and Electronic Systems Magazine April 2018 - 17
Aerospace and Electronic Systems Magazine April 2018 - 18
Aerospace and Electronic Systems Magazine April 2018 - 19
Aerospace and Electronic Systems Magazine April 2018 - 20
Aerospace and Electronic Systems Magazine April 2018 - 21
Aerospace and Electronic Systems Magazine April 2018 - 22
Aerospace and Electronic Systems Magazine April 2018 - 23
Aerospace and Electronic Systems Magazine April 2018 - 24
Aerospace and Electronic Systems Magazine April 2018 - 25
Aerospace and Electronic Systems Magazine April 2018 - 26
Aerospace and Electronic Systems Magazine April 2018 - 27
Aerospace and Electronic Systems Magazine April 2018 - 28
Aerospace and Electronic Systems Magazine April 2018 - 29
Aerospace and Electronic Systems Magazine April 2018 - 30
Aerospace and Electronic Systems Magazine April 2018 - 31
Aerospace and Electronic Systems Magazine April 2018 - 32
Aerospace and Electronic Systems Magazine April 2018 - 33
Aerospace and Electronic Systems Magazine April 2018 - 34
Aerospace and Electronic Systems Magazine April 2018 - 35
Aerospace and Electronic Systems Magazine April 2018 - 36
Aerospace and Electronic Systems Magazine April 2018 - 37
Aerospace and Electronic Systems Magazine April 2018 - 38
Aerospace and Electronic Systems Magazine April 2018 - 39
Aerospace and Electronic Systems Magazine April 2018 - 40
Aerospace and Electronic Systems Magazine April 2018 - 41
Aerospace and Electronic Systems Magazine April 2018 - 42
Aerospace and Electronic Systems Magazine April 2018 - 43
Aerospace and Electronic Systems Magazine April 2018 - 44
Aerospace and Electronic Systems Magazine April 2018 - 45
Aerospace and Electronic Systems Magazine April 2018 - 46
Aerospace and Electronic Systems Magazine April 2018 - 47
Aerospace and Electronic Systems Magazine April 2018 - 48
Aerospace and Electronic Systems Magazine April 2018 - 49
Aerospace and Electronic Systems Magazine April 2018 - 50
Aerospace and Electronic Systems Magazine April 2018 - 51
Aerospace and Electronic Systems Magazine April 2018 - 52
Aerospace and Electronic Systems Magazine April 2018 - 53
Aerospace and Electronic Systems Magazine April 2018 - 54
Aerospace and Electronic Systems Magazine April 2018 - 55
Aerospace and Electronic Systems Magazine April 2018 - 56
Aerospace and Electronic Systems Magazine April 2018 - 57
Aerospace and Electronic Systems Magazine April 2018 - 58
Aerospace and Electronic Systems Magazine April 2018 - 59
Aerospace and Electronic Systems Magazine April 2018 - 60
Aerospace and Electronic Systems Magazine April 2018 - Cover3
Aerospace and Electronic Systems Magazine April 2018 - Cover4
http://www.brightcopy.net/allen/aesm/34-2s
http://www.brightcopy.net/allen/aesm/34-2
http://www.brightcopy.net/allen/aesm/34-1
http://www.brightcopy.net/allen/aesm/33-12
http://www.brightcopy.net/allen/aesm/33-11
http://www.brightcopy.net/allen/aesm/33-10
http://www.brightcopy.net/allen/aesm/33-09
http://www.brightcopy.net/allen/aesm/33-8
http://www.brightcopy.net/allen/aesm/33-7
http://www.brightcopy.net/allen/aesm/33-5
http://www.brightcopy.net/allen/aesm/33-4
http://www.brightcopy.net/allen/aesm/33-3
http://www.brightcopy.net/allen/aesm/33-2
http://www.brightcopy.net/allen/aesm/33-1
http://www.brightcopy.net/allen/aesm/32-10
http://www.brightcopy.net/allen/aesm/32-12
http://www.brightcopy.net/allen/aesm/32-9
http://www.brightcopy.net/allen/aesm/32-11
http://www.brightcopy.net/allen/aesm/32-8
http://www.brightcopy.net/allen/aesm/32-7s
http://www.brightcopy.net/allen/aesm/32-7
http://www.brightcopy.net/allen/aesm/32-6
http://www.brightcopy.net/allen/aesm/32-5
http://www.brightcopy.net/allen/aesm/32-4
http://www.brightcopy.net/allen/aesm/32-3
http://www.brightcopy.net/allen/aesm/32-2
http://www.brightcopy.net/allen/aesm/32-1
http://www.brightcopy.net/allen/aesm/31-12
http://www.brightcopy.net/allen/aesm/31-11s
http://www.brightcopy.net/allen/aesm/31-11
http://www.brightcopy.net/allen/aesm/31-10
http://www.brightcopy.net/allen/aesm/31-9
http://www.brightcopy.net/allen/aesm/31-8
http://www.brightcopy.net/allen/aesm/31-7
https://www.nxtbookmedia.com