http://www.auvsi-suas.org/competitions/2017/
These are the autopilots that each of teams indicate that they were using in the competition. Awesome to see this kind of performance by ArduPilot and congratulations to each of the teams who competed.
1 ArduPilot
2 ArduPilot
3 ArduPilot
4 ArduPilot
5 ArduPilot
6 ArduPilot
7 PX4
8 Piccolo
9 ArduPilot
10 PX4
11 Paparazzi
12 Ardupilot
13 ArduPilot
14 PX4 I think
15 ArduPilot
16 ArduPilot
17 Pixhawk Mini but autopilot software is not mentioned
18 ArduPilot
19 ArduPilot Interesting table on page 4 of #19
20 ArduPilot