Learning Objectives Download data from the automatic control system. Convert EEProm Arduino data readouts to physical engineering parameters such as distance traveled and velocity. Calculate the performance characteristics of the AEV.
Recap – System Analysis 1 In System Analysis 1, we downloaded data from the automatic control system to calculate: Time Input Power, Current Incremental Energy, Voltage Total Energy,
System Analysis 2 Now we’re going to make use of the wheel counts recorded by the AEV and compute the following: Distance Velocity Kinetic Energy s = distance (meters) v = velocity (meters/seconds) s = distance (meters) t = time (seconds) KE = Kinetic Energy (joules) m = Mass (kilograms) v = velocity(meters/second)
System Analysis 2: AEV Performance Characteristics
AEV velocity can be easily computed. The propeller RPM is a function of the current being supplied to the motor by the command inputs. The following are sample equations for RPM*: *We will revisit the RPM curves in System Analysis 3 and update the equations above.
The Advance Ratio RPM = Revolutions per Minute v = velocity(meters/second) D = Propeller Diameter (meters)
Some Advance Ratio Limits At low motor speeds (~10% or lower) the propeller RPM becomes difficult to measure. To filter out bad data, constraints are used when computing the Advance Ratio. First, compute advance ratio: Second, apply constraints: