2017 Robots:

Our robots we made in 2017 used the same sensors and motors from 2016. Our 2017 robots have a better frame, better programming, extra actuators and extra sensors. Notable things include:

  • 3D printing
  • A kicker system which we designed a built, it includes:
    • Power delivery
    • Electric solenoid
    • Hinge plate
  • A camera (PixyCam)
  • Detection of ball possession
  • Using multiple processors
  • Infrared sensors (TSOP4840s)
  • Redesigned frame
  • More ultrasonics sensors

3D Printing:

We used 3D printed parts on our robots in 2017 for various purposes. One such purpose is housing the infrared sensors. This allowed us to easily slot them into holes which made aligning and setting them up easily. This also allowed us to limit the angle of light allowed.

Below is a video of the construction of our robots for the 2017 competition.

Kicker:

The kicker was made of:

  • A 6-layer coil around 50mm long.
  • It was made of enameled 16AWG wire
  • A 13mm steel plunger was used.
  • Voltage increased to 23v with a voltage regulator.
  • 3 x 10,000µF 25v capacitors @ 23v
  • A 30V 30A relay board
  • Half of a steel door hinge.

Camera:

We used a pixy camera. This was used to collect information about the goal's locations. The data was gotton off the camera over I2C and then code got the largest block of the goal's colour location and size. The goal's location and size on the camera was used to line the robot up with the goal and kick when close if the robot possesed the ball.

Detection of ball possession:

A laser gate of 2 lasers was used in combination with a forward-facing infrared sensor on the lower level (under the kicker) to decide when the robot has the ball.

Multiple processors:

Multiple processors were used to reduce interference and allow for more pins. This allowed us to use an Arduino Nano to control the kicker and motors. We then used I2C to communicate between the Nano and the central Arduino Mega 2560 processor.

Infrared Sensors:

We used a backfacing IR sensor to know if the ball was behind the robot to prevent it from knocking it backwards and scoring own goals. We also used a IR sensor to detected if a ball was in the capture zone, placed under the kicker.

As in 2017 we used TSOP4840s they are a lot harder to use compared to the TSOP31140s. But can have significantly more range. The TSOP4840's range decreases rapidly after power up, to around 50cm, 3+ metres on power up. (compared to the TSOP31140s which does the opposite). This mean they are required to be reset around every 10 milliseconds to be usable.

Redesigned Frame:

The frame was made of a combination of plastic and metal, a list of main parts is:

  • Bottom plate - 2mm aluminium with lots of large holes drilled in it to reduce weight.
  • Middle plate - 3mm Laminex with cut-outs with a jigsaw to reduce wait.
  • 6 x Support between bottom and middle plates - 60mm long aluminium extrusion with holes to put screws into.
  • Upper mounting bar - Piece of bent aluminium with holes drilled in to reduce weight, was used to mount:
    • Handle - plastic tube
    • Camera
    • Compass
    • Bumpers - stops robot jarring into the goals
    • 18650 single cell battery box
  • 2 x Rear protection poles - cutup and bent pieces of bent aluminium, stops the robot going backwards into the goal.
  • 4 x Plastic standoffs - supports the main circuit board.

Using 4 ultrasonic sensors:

4 ultra sonic sensors (facing front, back, left and right) were used over the 2016 robots 2 (front and back), this allowed us to tell which quadrant of the field the robot is in. This is important for making sure the robot moves away from the white line, as it will also allow a robot to move back over the white line as well using just one colour sensor.

List of 2017 components:

  • 1 x Aluminium Base plate - 2mm plate
  • 1 x Outer Shield 1mm aluminium(State), 1mm Polycarbonate(Nationals)
  • 3 x Pittman PG6212a008 10.8V with 23:1 metal planetary gearbox motors.
  • 3 x Omni Wheels
    • 3D printed housing
    • 15 x Rollers (O-Ring on V-Groove bearing)
    • 1 x Key ring (holds rollers into housing)
  • 1 x Kicker
    • Solenoid
      • 6 layers of 16 AWG enameled copper wire, winded around a 14mm diamter 50mm long core
      • 1 x Flyback diode
    • Power supply
      • 3 x 10,000µF 25v electrolytic capacitors
      • 1 x 30A 30v relay (triggered by 5v)
      • 1 x DC-DC step-up voltage regulator
    • Plunger & Plate
      • Steel door hindge with foam on it (to not damage the ball)
      • Plunger is M13 steel shaft
      • 1 x Rubber band - pulls the plunger back
  • 1 x TCS230 Colour Sensor
  • 1 x 3D printed Colour Sensor Mount and Shield
  • 3 x Aluminium Motor Mounts - 3mm angle
  • 1 x 5A DC-DC adjustable step-down XL4005 Voltage regulators
  • 3 x L298N dual full-bridge motor driver
  • 14 x TSOP4840 infrared sensor
  • 1 x 7.5amp Main Fuse and Holder
  • 2 x 5V Laser Receiver
  • 2 x Laser emitter
  • 1 x 3mm Laminex plate
  • 1 x Battery Box (holds 4 18650 cells in series)
  • 1 x Battery protection board PCB BMS for 18650 batteries
  • 5 x 18650 Li-ion 3.7v batteries
  • 2 x Rear protection poles, Aluminium
  • 3D Printed Infrared Mounts
    • 1 x Front bar housing
    • 1 x Back housings
    • 2 x Side housings (mirror images)
    • 1 x Under kicker housing
  • 4 x Ultrasonic Sensors HC-SR04
  • 4 x Ultrasonic Sensor Mounts
  • 1 x Green project circuit board 15cm x 9cm
  • 2 x On/Off Rocker Switch H2S8 S2V0 10A/125V 2 Solder Lug
  • 1 x ATMega2560 Control Board
  • 4 x Plastic supports
  • 1 x Pixy Camera, CMUcam5 from Charmed Labs
  • 1 x Pixy Cam 3D printed mount, Custom design 3D printed.
  • 1 x Single cell lithium ion battery box
  • 1 x Jumper
  • 2 x buttons for sensors, Miniature Micro Switch PCB 6x6x4.5 mm
  • 1 x Compass HMC5983
  • 1 x Electrical Panel Mounted 5 x 20mm Fuse/Holder 1A
  • 1 x Aluminium protection/mounting bar
  • Lots of wire, nuts, bolts and screws