Helicopter Data Acquisition System ECE 4522 Senior Design II

Team Members David Paul Aaron Hill Robert McInnis Jason Schemmel Dr. Rob King (Advisor) (Advisor)

Team Responsibilities Aaron Hill (Power) Power consumption, PCB layout, and documentation David Paul (Controls) Control circuit design and synchronization Jason Schemmel (Communications) Antenna simulation, transmitter/receiver research, PCB layout Robert McInnis (Communications) Robert McInnis (Communications) Signal conditioning, sampling, and data conversion

Helicopter

Design Explanation Hub Blade Pivot Nonlinear stiffness spring POT Strain Gauge

Design Explanation HUB PIVOT Strain Gage

Design Explanation Position Transducer Battery Pack Power Source 900 Mhz Transmitter 2:1 Mux 10 bit A/D Converter Wheatstone Bridge Amplifier Signal Conditioner Strain Gauge KEYPowerSignal EM Signal BASIC Stamp Microcontroller

Design Explanation Helicopter House Power 10 bit D/A Converter KEY Power Signal EM Signal Data Enable 900 MHz Receiver LaptopLaptop Internal Sensor Package DAQ PCMCIA BASIC Stamp Microcontroller 10 bit D/A Converter

Status - Complete Transmission / reception Data conversion Acquisition instrumentation Power supplies Dual signal multiplexing BASIC Stamp programming/implementation

Status – Incomplete PCB Software Strain Gauge Signal Conditioner Adequate noise filtration

Simulation Comparison Control Signal Channel 1 Channel 0 Simulated Signal 5V 0V 5V 0V

Simulation Comparison Sampling Rate Transmitted Signal Input Signal (3Hz) Simulated Input Signal

Problems Solutions 1.Encoder/Decoder was slowing our sampling rate 2.Transmission Scheme transmitting unwanted address 10 kbps (22 bits per packet) 300MHz 3.Error checking overkill 1.Implemented BASIC stamp for quick custom solution 2.Using MHz scheme transmitting 2-10 bit packets 3.Parity checking performed by BASIC stamp

Problems Solutions 4.Multiplexor would not latch analog data for output 5.Overall system noise. 4.Used a dual D/A configuration with control logic tied to chip selects. 5.Each chip data sheet calls for different de-coupling capacitors, which will be utilized during PCB design stage.

PCB Design Receiver Schematic

PCB Design Used Microsim PC-Boards (P-SPICE) Encountered Node Limit (Shareware) Single sided  Decided to use Express PCB –Included CAD software –Double sided –Quick turnaround

Technical Challenges Remaining Final PCB Layout with size consideration Noise filtration during testing Calibration of acquisition devices (i.e. strain gage)

Placement of Transmitter Package Size limitations of PCB board (6”x2.5”) Proposed position of final installation of Transmitter PCB board.

Placement of Transmitter Package Packaging can be up to 2.5 inches tall Package will be secured to rotor tightly to prevent our hard work from slinging away

Timeline JanuaryFebruaryMarchAprilMay Prototype DAQ Software Testing/ Tweaking PCB Fabrication Final Documen- tation Preliminary Design Review Final Design Review Preliminary Hardware Review

Future Improvements Implement remote transmitting on/off switch Battery reduction circuitry Graphical User Interface (GUI) Automated helicopter control system Eliminate D/A conversion, allow Computer to do any needed operations to data

Helicopter Data Acquisition System ECE 4522 Senior Design II The End