IEEE Robotics Team 2021 - 1st Place!

/Engineering

Overview

 

The robot autonomously navigates a maze, acquires a “power pellet”, then navigates the maze to push the two “ghosts” out of their boxes.  

The IEEE SoutheastCon 2021 theme was loosely based on the Pac-Man arcade game. In this spin-off, a small robot must navigate to a designated area, secure the power pellet, and ‘eat’ (push) two stationary ghost blocks. The robot could also collect other blocks scattered throughout the board and return them to the starting location for additional points. 

In the initial setup phases, the operator used a rotary encoder and switches to input the location of the two stationary ghosts and the two blocks that represented the power and poison pellets located in opposite corners of the board. The two ghosts were differentiated by a triangle or circle painted on them, and corresponded to a pellet with the matching shape. A judge then announced which of the two pellets was designated as the power pellet, and the operator relayed this information to the robot verbally. Then, without any further input from the operator, the robot would navigate to the corner with the power pellet, use a computer vision system to determine the exact location of the power pellet within the space, and align itself with the pellet. Next, an arm with an adhesive plate would rotate over 180 degrees to adhere to the block and collect it. Once the power pellet was secured, the robot would autonomously realign itself on the board and proceed to push the ghost with the shape matching the power pellet out of position. Finally, the robot would navigate to the second ghost and make contact with it. 

Clemson’s team dominated in this year’s competition, attaining first place in qualifying rounds and finishing the final four rounds with a cumulative score of 920 points. The second and third place winners scored 570 and 220 points respectively in the final four rounds. 

 

My role in the team was the team leader and the teaching assistant (TA) for the team/Creative Inquiry course with it.  
 

Noteworthy Hardware

 
  • Distance Sensors:  APA102 Daylight white DC5V 144LEDs/m Programmable Led Strip Lights [link]
    • One of the only addressable, white-only LED strip we could find with 144 LED/m density.  ​Price is 1/3 of Adafruit DotStar
  • Servo Motor:  Falcon F16V3​ [link]
    • Used Falcon instead of Kulp because Falcon is the only common controller that supports APA102 protocol (Data line connector)​
  • Main Controller:  Falcon Pi Player (FPP) on a BeagleBone Black 
  • Vision System:  TP-Link TP-SG105 [link]
  • Enclosure:  BUD NBF-32026 [link]
  • Connectors
    • Power Distribution:  XT-60​
    • To LED strips:  BTF Lighting 4-pin waterproof connectors [link]
  • Power supplies:  PF-320-5 5V 320W power supplies. ​

Software

 
xLights was used to program the animations on the sign.  It is designed for the Christmas light display hobby but works perfectly here.  I set up the layout of the sign in xLights so that the program knows where each LED is in space.  This basically tells the program that "light 100 on strip 1 is at the top left of the furthest left hexagon", so that when you run an effect on the sign it knows to turn on that light at the proper time.   After setting up the layout it is easy to apply a wide variety of effects to the sign. 
I was going to draw a diagram for this, but the software side of the sign is more or less Network Switch --> FPP and Network Switch --> F16V3.   Both devices are connected to the network switch and get their own IP address, and you simply tell FPP the IP address of the controller it is talking to.  FPP (Falcon Pi Player) is where I upload the finished animation files and different effects can be scheduled for different times.  It also runs a simple script that cycles through the animations each time you press the button.  
xlights.jpg
xLights "Layout" tab of the LED strips

More Pictures