RC08Brushless

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Revision as of 23:49, 9 September 2007 by Marksp (talk | contribs) (Specifications)
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In 2008 RoboCup switched to brushless DC motors. While brushless motors are smaller and far more efficient than brushed motors the commutation normally performed inside a brushed DC motor will need to be done externally using some control circuitry. There are two main parts to our brushless motor controller solution; the controller which uses sensors on the motor to gate signals to one of three coils, and the half-bridge motor drivers which actually drive the coils. There are two design paths: one with a special purpose controller, and one with a CPLD as the controller. On this page you will find information about both. For information on the motors or motor control software please see their respective pages.

Task

  • [ ] Finalize on a DSC
  • [ ] Choose Half-Bridge Drivers
  • [ ] Set-up test-bed
  • [ ] Build prototype system
  • [ ] Choose CPLD
  • [ ] Choose MOSFET Drivers
  • [ ] Build 2nd prototype
  • [ ] Choose final solution


Specifications

Motor Controller Chip

  • The motor is spec'd at 12V and is 30W so that means we drawn 833mA per channel
  • A decent transient response (This will be a function of hardware and software)
  • 3-Channels in one package
  • Braking is not a requirement but would be nice (We could just as easily do it software)
  • High Impedance OFF state
  • 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

MOSFET

  • Depletion Mode
  • Probably an NMOS and a PMOS
  • I want to say 10A as the data sheet for the motor gives a 10A starting current but I need to check with someone

Schematics

Schematics

Parts

DSC

CPLDS

Half-Bridges

MOSFET Drivers

Articles

Links