Aerospace and Electronic Systems Magazine September 2016 - 37


Liu and Foina

Figure 5.

Summary of WCERT for the horizontal safety controller (rmin = 20 m).

quadrotor. With both RI and drag (Figure 5(b)), the WCERT decreases as amax increases. It says that as amax gets larger, it becomes
easier to overcome the drag, and the WCERT becomes smaller. To
take into account the communication delay, one can simply add the
delay (2.0 s for ADS-B) on top of Figure 5.

HYBRID CONTROLLER
We tested the hybrid controller extensively in a wide range of scenarios to prove its effectiveness. Here we only present a typical
package-delivery scenario. A quadrotor is typically designed to
produce a maximum thrust of 2 mg, which can give a maximum
horizontal acceleration of 14 m/s2 when hovering. Figure 6 shows a
high-speed high-acceleration scenario. In Figure 6(a), the quadrotor takes off from the origin and is trying to get to the point (X, Y,
Z) = (500 m, 500 m, -100 m) when a helicopter is flying toward
it in a straight line. The horizontal position signals of both the helicopter and the quadrotor are contaminated with Gaussian white
noise with a standard deviation of 5 m. In addition, the quadrotor is
experiencing a horizontal wind disturbance of Vwind similar to [43].
In this scenario, the parameters are

By employing the safety controller, the quadrotor successfully
avoids the helicopter and gets to the final destination (Figure 6(a)).
Assume that there is no communication delay, when the WCERT
is set to 0.1 s, the minimum relative distance between the two vehicles is 21.8 m, which is barely larger than the nominal threshold
rmin = 20 m, indicating that the safety controller performs almost
optimally. Note that if the vehicles are equipped with ADS-B, the
WCERT should take into account the 2.0 s communication delay,
giving a WCERT value of 2.1 s.
Figure 6(b) shows the time history of the horizontal command
and control signals. In the X, Y, and Z time history plots, the red
dashed lines indicate desired destination, and the black solid lines
give the actual flight trajectory. In the q and f plots, the blue dashed
lines show the command generated from the angle controller, and
the red dashed lines give command from the position controller. At
the beginning, position control is enabled, and the actual trajectory
(solid black) follows the position control command. At time t = 6.7
s, the quadrotor switches to the safety (angle) control until t = 8.3

Figure 6.

The quadrotor avoids a helicopter on the way to a destination.

SEPTEMBER 2016

IEEE A&E SYSTEMS MAGAZINE

37



Table of Contents for the Digital Edition of Aerospace and Electronic Systems Magazine September 2016

No label
Aerospace and Electronic Systems Magazine September 2016 - No label
Aerospace and Electronic Systems Magazine September 2016 - Cover2
Aerospace and Electronic Systems Magazine September 2016 - 1
Aerospace and Electronic Systems Magazine September 2016 - 2
Aerospace and Electronic Systems Magazine September 2016 - 3
Aerospace and Electronic Systems Magazine September 2016 - 4
Aerospace and Electronic Systems Magazine September 2016 - 5
Aerospace and Electronic Systems Magazine September 2016 - 6
Aerospace and Electronic Systems Magazine September 2016 - 7
Aerospace and Electronic Systems Magazine September 2016 - 8
Aerospace and Electronic Systems Magazine September 2016 - 9
Aerospace and Electronic Systems Magazine September 2016 - 10
Aerospace and Electronic Systems Magazine September 2016 - 11
Aerospace and Electronic Systems Magazine September 2016 - 12
Aerospace and Electronic Systems Magazine September 2016 - 13
Aerospace and Electronic Systems Magazine September 2016 - 14
Aerospace and Electronic Systems Magazine September 2016 - 15
Aerospace and Electronic Systems Magazine September 2016 - 16
Aerospace and Electronic Systems Magazine September 2016 - 17
Aerospace and Electronic Systems Magazine September 2016 - 18
Aerospace and Electronic Systems Magazine September 2016 - 19
Aerospace and Electronic Systems Magazine September 2016 - 20
Aerospace and Electronic Systems Magazine September 2016 - 21
Aerospace and Electronic Systems Magazine September 2016 - 22
Aerospace and Electronic Systems Magazine September 2016 - 23
Aerospace and Electronic Systems Magazine September 2016 - 24
Aerospace and Electronic Systems Magazine September 2016 - 25
Aerospace and Electronic Systems Magazine September 2016 - 26
Aerospace and Electronic Systems Magazine September 2016 - 27
Aerospace and Electronic Systems Magazine September 2016 - 28
Aerospace and Electronic Systems Magazine September 2016 - 29
Aerospace and Electronic Systems Magazine September 2016 - 30
Aerospace and Electronic Systems Magazine September 2016 - 31
Aerospace and Electronic Systems Magazine September 2016 - 32
Aerospace and Electronic Systems Magazine September 2016 - 33
Aerospace and Electronic Systems Magazine September 2016 - 34
Aerospace and Electronic Systems Magazine September 2016 - 35
Aerospace and Electronic Systems Magazine September 2016 - 36
Aerospace and Electronic Systems Magazine September 2016 - 37
Aerospace and Electronic Systems Magazine September 2016 - 38
Aerospace and Electronic Systems Magazine September 2016 - 39
Aerospace and Electronic Systems Magazine September 2016 - 40
Aerospace and Electronic Systems Magazine September 2016 - 41
Aerospace and Electronic Systems Magazine September 2016 - 42
Aerospace and Electronic Systems Magazine September 2016 - 43
Aerospace and Electronic Systems Magazine September 2016 - 44
Aerospace and Electronic Systems Magazine September 2016 - 45
Aerospace and Electronic Systems Magazine September 2016 - 46
Aerospace and Electronic Systems Magazine September 2016 - 47
Aerospace and Electronic Systems Magazine September 2016 - 48
Aerospace and Electronic Systems Magazine September 2016 - 49
Aerospace and Electronic Systems Magazine September 2016 - 50
Aerospace and Electronic Systems Magazine September 2016 - 51
Aerospace and Electronic Systems Magazine September 2016 - 52
Aerospace and Electronic Systems Magazine September 2016 - 53
Aerospace and Electronic Systems Magazine September 2016 - 54
Aerospace and Electronic Systems Magazine September 2016 - 55
Aerospace and Electronic Systems Magazine September 2016 - 56
Aerospace and Electronic Systems Magazine September 2016 - 57
Aerospace and Electronic Systems Magazine September 2016 - 58
Aerospace and Electronic Systems Magazine September 2016 - 59
Aerospace and Electronic Systems Magazine September 2016 - 60
Aerospace and Electronic Systems Magazine September 2016 - 61
Aerospace and Electronic Systems Magazine September 2016 - 62
Aerospace and Electronic Systems Magazine September 2016 - 63
Aerospace and Electronic Systems Magazine September 2016 - 64
Aerospace and Electronic Systems Magazine September 2016 - 65
Aerospace and Electronic Systems Magazine September 2016 - 66
Aerospace and Electronic Systems Magazine September 2016 - 67
Aerospace and Electronic Systems Magazine September 2016 - 68
Aerospace and Electronic Systems Magazine September 2016 - Cover3
Aerospace and Electronic Systems Magazine September 2016 - 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