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uscauv-legacy / old-uscauv-ros-pkg

ROS software used on robots made by the USC AUV Team.
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Motor Values Are Not Physical #2

Closed uscauv closed 11 years ago

uscauv commented 11 years ago

The current robot driver (seabee3_driver) controls motors by sending MotorVals to the Propeller microcontroller on the power board. Because we do not have the source code for the firmware running on the Propeller, it is a black box. That is, we do not have any insight into how it interprets MotorVals and how they correspond to thruster power consumption. Each MotorVal is a scalar between on the range [-100, 100].

canondetortugas commented 11 years ago

Because the new Kanaloa motor driver board will have voltage and current sensing, we can use 1D PID controllers on each motor channel to accurately set the power of each thruster. This will allow us to set motors in units of Watts. When we do our test to characterize the thrusters, we will come up with a mapping from power in Watts to thrust in Newtons.

canondetortugas commented 11 years ago

Made new MotorPower and MotorPowerArray messages. Each MotorPower message has a power in watts and a name for the thruster it is associated with.