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Summer 2002

Robotic Autonomy Institution

Robot and Software Design:

These modelling sketches show the TrikeBot's striking features: the three large wheels and large base, designed for easy but stable maneuvering, just like a tricycle. The long neck projects from the front driving and steering wheel to support the trikebot’s new, low-cost camera, CMUcam. The TrikeBot can swivel the camera around two axes.

Like a child’s trike, the robot is designed to be a fun sidekick the Robotic Autonomy student can rely on as they gain more experience in the world of robotics.



Robot Construction:

Download movie of students' assembly work.

The parts are all laid out by TrikeBot designer Tom Hsiu, ready for Robotic Autonomy students to build their 'bots. Hsiu has participated in creating other robots that can be seen on the silver screen: the snake in Anaconda and the killer whale in Free Willy 2.


Robot Control:

A Compaq iPAQ handheld computer provides wireless communication to the students' notebook to enable controlled movement of the TrikeBot. The iPAQ also provides the processing power for real-time color tracking. The iPAQ is connected via a serial interface to both the CMUcam and two BrainStem™ controllers made by Acroname. The modifications (in red) protect the onboard code from being overwritten.

  • The BrainStem™ Moto uses a 3 Amp H-Bridge module to drive the main motor for forward and backward motion. A unique Back-EMF measurement approach is incorporated into the H-Bridge module to allow measurement of the motor speed without an expensive encoder. This speed information is fed into a PID equation to produce high-speed (20 kHz) PWM (pulse width modulation) output to control the motor.
  • A second BrainStem™ controller, the GP 1.0, is used to control the steering servo, Sharp GP2D02 Infrared Sensor used for range-finding, and additional I/O. The two controllers communicate over an IIC bus at 1MBit and relay to the serial multiplexer connected to the iPAQ.

Robot Control:

The Trikebot software consists of firmware running the on-board iPAQ 3650 handheld computer, which acts as a serial-to-802.11 router as well as a real-time sensor-motor controller. In addition, the Trikebot development environment runs on the laptop, providing a JAVA interface from which to control and program the Trikebot. You can now download all of the source code for both the firmware, called TrikePaq2.2, and for the laptop, called TrikeBot2.1. NEW: An updated laptop project, TrikeBot2.2, has several significant improvements thanks to Eric Porter. The new file, TrikePaq2.3 is for the new CMU232 serial switcher board and will not work properly with RASC2002 graduates' robots.

  • This zip file contains documentation, including a user's manual for the Trikebot software and an architectural diagram.
  • This zip file contains all of the iPAQ firmware executable and source code for TrikePaq 2.2.
  • This zip file contains the iPAQ test executables, such as ServoTest and TrackTest and RangerTest, for exercising the 'bot without a notebook.
  • This zip file contains all of the JAVA source code for the Trikebot 2.1 notebook interface.
  • This zip file contains the Intel Wireless 802.11b driver for the iPAQ 3650 that we use.
  • This zip file contains the Intel Wireless 802.11b driver for your Windows 2000/XP notebook computer.
  • This zip file contains the iPAQ ActiveSync installer for a portable, so that you can sync to your iPAQ 3650 and transfer files to it.
  • This zip file contains Trikebot 2.2, a notebook interface that improves joystick operation and doubles communication rate.
  • This zip file contains Trikepaq 2.3, an iPAQ firmware release meant only for the CMU232 serial switcher. Not compatible with RASC2002 robots.