mid-semester design presentation senior design presentation october 1, 2009 contactless angular...
TRANSCRIPT
Mid-Semester Design PresentationSenior Design Presentation
October 1, 2009
Contactless Angular Position Sensor
Team Members
Eugene SandbergComputer Engineer
Tasks:-Construct Test Setup-Program Microchip
Christine BrattonElectrical Engineer
Tasks:-Research Magnets and Sensors-Program Microchip-Output Stage
Aram LeeElectrical Engineer
Tasks:-Research Magnets and Sensors-Program Microchip
Jeremy LewisComputer Engineer
Tasks:-Construct Test Setup-Packaging-Layout
Matt LandryElectrical Engineer
Tasks:-Research Magnets and Sensors-Output Stage-Packaging
Outline
• Problem• Solution• Constraints
– Technical– Practical
• Alternatives• Progress
Problem and Solution
Problem Statement• The current sensor fails due to shaft mechanical
contact. • Each failure results in a significant cost for the Army since
they must replace the entire A-Arm.
Solution• Eliminate the mechanical contact by using a Hall effect sensor and a magnet attached to the rotating portion of the A-Arm. • The raw data output will be processed by the PIC24 and sent to
the output stage for amplification.• A test setup will be constructed that will allow us to test the
chosen sensors and magnets.• Finally, a mechanical prototype will be constructed using a 3D
CAD program.
Overview of Proposed Solution
Magnet
• Generates a magnetic
field.
Sensor
• Outputs a signal relative
to angular position.
Microprocessor
• Processes the signal from the sensor.
DAC/Amp
• Outputs analog
voltage. (0-24V)
System supply is 24V.
Constraints
• Technical Constraints
• Practical Constraints
Technical Constraints
• The CAPS must operate between -40 to 70 degrees Celsius
• The CAPS must be accurate to .1 degrees and measure an angle of 90 degrees.
Technical Constraints
• The CAPS must be driven by a 24 volt input and output a linear DC voltage ranging from 0 to 24 V.
• The CAPS must draw less than 24 mA.
• The CAPS must have a response time of 24 ms or less.
Practical Constraints
• Problem• Sustainability
– The CAPS must be contactless.
Practical Constraints
• Problem• Manufacturability
– The design must be easily produced and manufactured by an army subcontractor.
– Must Fit in End Cap – Same Casing
• Optical-Grease Interference-Outside of Vehicle-Particle Interference
• WiFi/Bluetooth-Complicated-Extra Power Source
Alternatives
Alternatives
Magnet A (Largest Magnet)
45 Degrees 90 Degrees 135 Degrees
5mm 1.08 2.5 3.64
10mm 1.07 2.49 3.67
15mm 1.08 2.52 3.66
20mm 1.09 2.48 3.62
25mm 1.09 2.48 3.61
30mm 1.1 2.4 3.61
Magnet B (Second Largest Magnet)
45 Degrees 90 Degrees 135 Degrees
5mm 0.726 2.5 3.74
10mm 0.799 2.49 3.62
15mm 0.906 2.49 3.54
20mm 0.96 2.43 3.52
25mm 1 2.43 3.5
30mm 1.06 2.44 3.5
Magnet C (Third Largest Magnet)
45 Degrees 90 Degrees 135 Degrees
5mm 1.43 2.99 3.88
10mm 1.49 2.94 3.85
15mm 1.49 2.87 3.88
20mm 1.49 2.81 3.88
25mm 1.47 2.79 3.87
30mm 1.48 2.75 3.85
Magnet D (Smallest Magnet)
45 Degrees 90 Degrees 135 Degrees
5mm DATA INCONSISTINT MAGNET TOO WEAK
10mm DATA INCONSISTINT MAGNET TOO WEAK
15mm DATA INCONSISTINT MAGNET TOO WEAK
20mm DATA INCONSISTINT MAGNET TOO WEAK
25mm DATA INCONSISTINT MAGNET TOO WEAK
30mm DATA INCONSISTINT MAGNET TOO WEAK
Magnet Comparison
Alternatives
Sensors, MAX548A, and PIC24 for Test and Implementation
MLX90316• Rotary Position IC• Hall Technology• Output Signal to PIC
PIC24• Process Sensor Signal• Talks to the MAX548A
KMA200• Analog Output• Will be used for initial testing,
Calibration of Test Setup
MAX5312EAE• DAC• 5V-10V
LM7321MA• OP AMP• Will output voltage of 0- 24
Progress
Test Setup
• Built Simulation Control Arm from PVC
• Mounted Arm on Test Bench
• Attached Magnet to Rotating Portion of Arm
• Mounted Sensor Setup Facing Magnet
-Sensor setup will consist of PIC24HJ64, a Hall Effect sensor, and the necessary circuitry
• Mounted Old Sensor on Backend for Comparison
Progress
Tasks/Dates
Research Sensor and Magnets
Construct Test Setup
Evaluate Angle Sensor 1
Output Stage
Investigate 3D CAD Packaging
Evaluate Angle Sensor 2
Interface with Microprocessor
Package Design
8/18 8/28 9/7 9/17 9/27 10/7 10/17 10/27
References
• [1] Karahalis, Alex. “Contacless Angular Position Sensor.” August 11, 2009.
• [2] SPG Media Group Ltd. “Stryker 8-Wheel Drive Armoured Combat Vehicles, USA.” 2009. [Online]. Available: http://www.army-technology.com/projects/stryker/ [Accessed: August 30, 2009].
?????
Questions