The Segbots (Two-wheeled Balancing Robots)
The Segbots are part of an ongoing inverted pendulum project in the Control Systems Labs. They use MEMS Inertial Measurement Units (IMUs) consisting of accelerometers and rate gyroscopes to determine their angular orientation. Coupled with a DSP or microcontroller and several other components, these sensors make it possible to stabilize the robot in the balancing position. These robots operate in much the same way as the Segway robots designed for personal transportation.
The Segboy is the MSP430-based variant of the Segbot family. It uses a TI MSP430F2272 16-bit microcontroller to read the sensors and issue control actions. This platform is used in ME 461, Computer Control of Mechanical Systems, to introduce students to embedded programming and control design. During the course they create models of the robot, then design and simulate their controllers. Students can use the robot in the stable configuration first (with a caster attached as the third wheel), then convert the robot to the unstable (inverted) position. To fit student's budgets, the Segboy uses 9-volt Faulhaber gearmotors with encoders that cost $7 each. The entire platform costs less than $200 to build.
The Segman (8.5M)
The Segman is a "beefed-up" version of the Segboy. By using a TI C2000F28335 Delfino floating-point microcontroller it gains greater speed and accuracy. The Segman is robust and capable of high speed. It is fitted with IR rangefinders and ultrasonic sensors for obstacle detection, a wireless modem, and a "leash" for steering. The compact size and affordability of TI's ezDSP packages make the Segman very easy to build and program.