Aerospace and Electronic Systems Magazine September 2016 - 36

An Autonomous Quadrotor Avoiding a Helicopter in Low-Altitude Flights

Figure 4.

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

quadrotor and helicopter are heading directly to each other. The
effect of RI, drag forces, and communication delay are evaluated.
The ranges for amax and v are chosen. A quadrotor can typically
produce a maximum thrust of twice its weight, or 2 mg, which
can generate a maximum horizontal acceleration of 17 m/s2 when
tilting at 60° at a constant altitude. Therefore, we picked amax to
be between 5 and 15 m/s2. A commercial helicopter typically has
a maximum horizontal speed of 70 m/s, while a quadrotor has a
maximum cruise speed of 30 m/s. Therefore, we set the maximum
horizontal relative speed v to be between 50 and 100 m/s.
For clarity, we only present WCMMD results for three relative speeds (Figure 4). Figure 4(a) shows the WCMMD result by
using the horizontal safety controller on a kinematic quadrotor. It
serves as the base of comparison. Figures 4(b), 4(c), and 4(d) give
the WCMMD results by using the horizontal safety controller on
a quadrotor with RI, drag, and communication delay, respectively.
The axis ranges are the same as Figure 4(a) for comparison purposes.
36

The WCMMD increases faster and faster from the lower-right
corner to the upper-left corner. In the lower-right corner, when amax
is high and v is low, we get small WCMMD ranging from 93 m
(no drag) to 202 m (with drag and communication delay). In the
upper-left corner, with small amax and large v, we get large WCMMD ranging from 293 m to 548 m. Compared with Figure 4(a),
RI gives a maximum of 10 m, or 3%, increase in the WCMMD.
The WCMMD increments due to drag are 55 m, or 18%, in the upper-left corner and 10 m, or 10%, in the lower-right corner. Lastly,
depending on the relative velocity v, the WCMMD increment of
communication delay range from 100 m (30%) to 200 m (60%).
The more interesting result comes in the WCERT maps. First,
the WCERT values without drag are always smaller than the ones
with drag. The WCERT ranges from 0.10 s to 0.22 s without drag
and from 0.30 s to 0.65 s with drag. Second, the two WCERT
maps in Figure 5 show opposite patterns with respect to amax. With
RI only (Figure 5(a)), the WCERT increase as amax increases. It
is because a larger amax implies a larger tilting angle (fd and qd),
which takes more time for the sliding mode controllers to rotate the

IEEE A&E SYSTEMS MAGAZINE

SEPTEMBER 2016



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