RC08Sensors

The 2007 robots had no on-board sensing and while using the camera to do most of the sensing worked the process is improved by adding sensor to the robots themselves. There are three new sensors for the robots in 2008: an IR LED ball sensor array, an encoder, and an accelerometer.

Tasks

IR LED Ball sensor

• [ ] Find an IR LED and a IR transistor
• [ ] Design the bandwidth filter and the Schmitt trigger circuits
• [ ] Build and test
  • [ ] Create a test-stand to test and verify ball sensor array performance
  • [ ] Build a prototype ball sensor system

Encoders

• [ ] Get final speed and wheel specs from ME team
• [ ] Find an optimal resolution versus frequency
• [ ] Select several parts and evaluate designs
• [ ] Write firmware to interface
• [ ] Integrate into velocity controller

Accelerometers

• [ ] Search for cheap part
• [ ] Write firmware to interface
• [ ] Integrate into velocity controller

Specifications

Motor Controller Chip

• The motor is spec'd at 12V and is 30W
• A decent transient response (dead-time + switching time)
• 3-Channels in one package
• Braking is not a requirement but would be nice
• High Impedance OFF state
• Fault protection (overvoltage, overcurrent, fast response)
• Small package
• Ability to operate in the >20kHz range
• Gate drive capability (either can directly driver the gate or is open drain.)
• Data sheet recommends a MOSFET
• Matrix of Potential Drivers

MOSFET

• Depletion Mode
• Probably an NMOS and a PMOS
• The FETS have to be able to handle 10A drain current
• Matrix of Potential FETS

Schematics

Schematics

Links

• Electrical System