Ford/Lincoln Company ECEN 4610 Critical Design Review February 25, 2003 Oliver Mansour, Dan Spendley, Davy Odom, Lincoln Ritchie, Kelli Settell

12 V DC SUPPLY FROM CAR DC INVERTER 300W, 110V AC SIG. COND W, 110 V AC SIG. COND W, 110 V AC ACCELEROMETERS (4) LAPTOP WITH DAQ CARD. dB SENSOR STRING POT. FOR PEDAL DISP. 9 V DC BATTERY LOAD CELL FOR PEDAL FORCE TACHOMETER CONTROLLER BOX Schematic for System Constant Voltage/ Current Source 68HC12 Micro- processor

Overall System Objectives Devise a means for relating subjective notions of performance feel to data taken during test-drive Sensory data must be processed into usable form before being sent to lap- top

Cleaning Signals Testing Each Sensor SensorSignal BufferControl Box 123

Existing Signals in the Lab Accelerometer from Signal ConditionerAccelerometer from Controller Box

Approaches to Noise Elimination Re-wire Shield Filtering

Filtering and Wiring Filtering Connections National Instruments SCB-68

EE System Objectives Eliminate extraneous components 2 Signal Conditioners Junction Box Wiring DAQ Processor can provide dynamic control

Sensor 1 Sensor 2 Sensor 8 Low-pass 1 Low-pass 2 Low-pass 8 Amplifier 1 Amplifier 8 Amplifier 2 Motorola 68HC12 Signal Conditioning Diagram

Low-Pass Filter/Amplifier

System Diagram Cigarette Lighter Regulated Boost Converter (15V) Potentiometer, Tachometer, Load cell Regulated Boost Converter (2-20mA) Tri-axis and Single-axis Accelerometers Regulated Boost Converter (100mA) Motorola 68HC12

Sensor Power Supplies Potentiometer – Constant Voltage Output based on input Voltage Tachometer Load Cell Output based on input voltage All these devices need constant 15V source and will draw less than 100mA

Regulated 15V from a 12V DC Source

Accelerometer Supplies Tri-axis Accelerometer Single-axis Accelerometer These sensors require 20 – 30V at 2 – 20mA

12-24V Boost Regulator

68HC12 Power Supply Processor requires 3-5V and Imax=100mA Use LP2980 Buck Regulator

Control Box Microprocessor 8 Sensor Inputs A/DMemory Filter/ Amplification Serial Link Calibration

Microprocessor Behavior Tachometer Readings Trigger Operation In operation Sampled signals saved in memory Information streamed from memory to serial output

Potential Auto Calibration Verify that signals are within acceptable ranges If not, feedback signals are sent back to filter/amplification LED indicates that calibration has been performed

EVB Schematic RS-232C Connector 68HC12 PAD 0-7 Inputs to A/D Converter

Project Schedule

Project Cost

Project Duties Davy- Processor Oliver- Processor Kelli- Signal Cleanup, Project Coordinator Lincoln- Signal Cleanup, Power and Conditioners Dan- Signal Cleanup, Power and Conditioners