Positioning Sensor for Electric Motor Drive ENGR 498 Senior Design College of Optical Sciences Industrial Affiliates
Overview Team Introduction Project Introduction System level overview Optical subsystem Electronics subsystem Project Summary
Team Members Daniel Alfred (Mechanical) – Project Lead Robert Nunes (Electrical) – Electrical Tech Lead Matthew Sinclair (Optics) – Optical Tech Lead Tim Spriggs (Computer) – System Lead Tracy Law (Optics) Dr. Mike Nofziger – Mentor Kevin Prodromides – Sponsor Christopher Scales - Sponsor
What are our options? CostProblems Optical Encoder$$ Electrical Resolver$$$$ Magnetic Sensor$$$$Jet Fuel/Pressure Hall Effect Sensor$Jet Fuel Variable ResistorsNALongevity
Big Picture =+
Customer Needs/ Requirements Measure the position of an electric motor shaft with an accuracy of 1.4 degrees Three sinusoidal outputs Operate efficiently at low and high speeds ( rpm) Signal output be compatible with the rest of the system Mechanical design integrates subsystems Submersed in pressurized jet fuel* Proof of concept
System Diagram
Outputs overview
Overall System
Optics Optical Design Size Size of design
Optics Optics allow for spatial filtering
Optics Through-focus spot size at the encoder disk Spot size at detector (16 mm away from disk)
Optics
Electronics Schematic Sensor A Sensor B 8 bit Position
Optics
Summary Goal: determine the position of the shaft Optical encoder Allows for spatial filter Digital circuitry with error bit Encapsulated housing
Questions and Concerns
Backups
Gantt Charts
Prototype Cost Focus areaCostParts Optics<$300 Laser diode, lenses, encoder disc Electronics<$80 ICs, OpAmps, diodes, resistors MechanicsTBD Mounting parts Miscellaneous<$40 Shipping
Optics Testing will be done by profiling the laser using a knife edge test. The beam will be approximated to be a Guassian for calculations
Optics Test Setup Knife edge will be scanned across beam Detector will measure power This will measure –Divergence –Beam waist
System flowchart
Transmission of Kerosene and JP8
Absorption curve for JP8