Today, we would like to introduce Terrabot, our Terrain Traveling Robot. Based on a modified “rock crawler” chassis, its primary purpose is to traverse rocks, branches, steep slopes, flower beds, boulders, mountain trails, and other extremely rough terrain.
We would like to introduce Mechatron, our mechatronic tank. When we designed and built Mechatron we wanted him to be tough looking, industrial, and retro-futuristic, with lots of metal, rivets, and gears. He’s built entirely out of aluminum, brass, and steel, but inside, he’s chock-full of high tech electronics. See pictures and more text below. And be sure to watch the video to see Mechatron in action!
Mechatron includes special wheels with rollers slanted at 45 degree angles and driven by dedicated gearboxes, four powerful motors, and a software-controlled drive system that we wrote that operates each of the wheels independently. The result is that he can move in any direction at any time in any orientation. In other words, he can drive forward and backwards or turn like a normal vehicle, but he can also drive perpendicular to the direction he’s facing or at any desired angle. Weighing in at forty five pounds, he is by far our heaviest robot, but he is also our most agile, which makes him tremendous fun to drive.
Mechatron’s gun turret pans 360 degrees, includes 8 range-finding sonars for target detection, a laser, and a high-powered electric automatic weapon that shoots brass or plastic pellets. Ammunition is fed from the base of the robot up through one of the articulated metal tubes attached to the turret (the other tube contains wires). He can fire extremely rapidly while standing still or moving.
Strips of 52 programmable RGB LED lights have been mounted on Mechatron’s underside and within his turret. The turret LEDs indicate the robot’s current mode and whether the weapon system is armed. The LEDs on the underside change color depending on the direction of each of the individual wheels (Blue = Stopped. Green = Forward. Red = Backward), which helps to illuminate how Mechatron’s unique drive system works.
Mechatron is designed to function in a variety of different modes, including both user-controlled Radio Control and/or fully-autonomous. For the RC mode, we built our own controller which matches Mechatron in look-and-feel. The left joystick controls the pan and tilt of the gun turret and includes the firing button on top (which is armed using the missile switch). The right joystick controls the drive system. Forward and Backward motion (Y-axis) moves the robot forward or backward. Twisting the joystick turns the robot in the direction of twist (Z-axis). Moving the joystick left or right (X-axis) causes the robot to strafe left or right while maintaining his current orientation. Combined X-Y-Z joystick motions create unique and agile movements, such as strafing in circles. The robot can move in any direction, while panning and tilting its turret and firing all at the same time.
- Overall Design: Beatty Robotics
- Arduino Software: Beatty Robotics
- Metal armor plates: Beatty Robotics
- Main Microcontroller: Arduino Mega 2560
- Microcontroller used for controlling LED lights: Arduino Nano
- Light Controller Software: Beatty Robotics
- Wheels: AndyMark (special thanks to Andy Baker, who was great to work with on these)
- Drive Gears: Modulox (special thanks to Dan Richardson at iR3 Creative Engineering & Andy Baker at AndyMark)
- Pan-Tilt gears and other parts: RobotZone (special thanks to ServoCity)
- Pan-Tilt Servos: Hitec Digital
- Sonars: (12) Maxbotix MaxSonar Ultrasonic Sensors
- Turret Sensor Head: Beatty Robotics
- RGB LED strips: Adafruit (Go Blinky Belt!)
- MP3 Sound Board: Sparkfun MP3 Trigger
- Servo Controller: Pololu Maestro
- Voltage Regulators: Pololu & Dimension Engineering
- High-amp Relays: DFRobot
- Motor Controllers: (2) Dimension Engineering Sabertooth 2×25
- Motors: (4) CIM
- Wireless Communication: Xbee Radio with Sparkfun Xbee Explorer Regulated board
- Joy Sticks: (2) 3-axis hall-effect joysticks from CH Products
- Batteries: (1) 12v 3-cell Lithium-Polymer 20C
- Aluminum, hardware, fasteners, wire, tools, and much else: McMaster-Carr
- Wire, electronic components, IC boards, and much else: Sparkfun & RobotShop
Imagine I’m out in the world. I can use my laptop or any other computer to link into the robot through the Internet. The people around the robot see my face on the robot’s screen. The sound of my voice comes through the speakers, which are mounted just below the screen. I hear through the robot’s microphone and I see through the robot’s camera, which is mounted on two little servos, so I can tilt and pan the camera where I wish to look. I can drive the robot around the house, to the kitchen or the bedroom or where ever, using the robot’s built in motors. His wheels are designed to drive or turn on carpet, tile, and hardwood floors.
How We Built Him
Telegance was a lot of fun to build, but he was definitely one of our most challenging robots so far. We learned a lot. Telegance is our first robot that is based on a computer rather than a microcontroller chip/board. Our vision was to build a robot based on a Mac. So, we grabbed a Mac Mini, tore it apart, ripped everything off that we didn’t need, rewired it for DC (it was an AC computer), and replaced the conventional hard drive with a Solid State Drive (SSD) (so that we didn’t need a fan, it didn’t make any noise, and it used less power). We installed just the stripped down motherboard into the base of the robot. When it booted up it was silent, fast, and ran on 12 volts like the rest of the robot. We then connected this to an Arduino Mega microcontroller through a USB cable. The Mac Mini, which runs a special Skype plugin, handles the webcam videoconferencing (using Skype), the touch screen, and 802.11b networking. The Arduino handles the drive motors, the webcam pan-tilt servos, power distribution, and other robotic features. We constructed the robot’s frame in our workshop using raw aluminum plate and c-channel. We especially like the cool wheels on this robot.