1. P08310
PNEUMATICALLY CONTROLLED AUTOMATED SHIFTING SYSTEM FOR A POLARIS OUTLAW 525 /
Polaris Industries - Joel Notaro (Sponsor)
Professor George Slack (Team Guide)
Eric Gambon (ISE)
Tim Faulhaber (ME)
Mishal Patel (EE)
Nathan Almeter (ME)
James Leon (EE)
Ajay Vangapaty (EE)
MISSION STATEMENT:
TO DESIGN, BUILD AND FIELD TEST A RAPID AND EFFICIENT DYNAMIC SHIFTING SYSTEM INTEGRATED INTO THE CURRENT ENGINE PLATFORM OF A POLARIS OUTLAW 525 RACING ALL TERRAIN VEHICLE.
MOTIVATION:
MANUAL SHIFT TRANSMISSIONS ARE INHERENTLY MORE EFFICIENT THAN AUTOMATIC TRANSMISSIONS
AUTOMATIC TRANSMISSIONS ARE DESIRABLE BECAUSE OF THEIR EASE OF USE – ESPECIALLY IN CHALLENGING OFF ROAD TERRAIN
BACKGROUND:
THIS FIELD OF RESEARCH HAS HAD MULTIPLE CONTRIBUTERS INCLUDING:
FORMULA 1 CARS USE OF “PADDLE” SHIFTERS
THE YAMAHA FJR1300 MOTORCYCLE FEATURES AN AUTOMATED 5-SPEED GEARBOX WITH A CLUTCH CONTROLLER AND ELECTRONIC SHIFT ACTUATOR FOR ‘CLUTCHLESS’ MANUAL OPERATION
ADDITIONAL INFORMATION:
FOR ADDITIONAL INFORMATION VISIT OUR TEAM WEBSITE ONLINE AT:
CONCEPT SELECTION:
MULTIPLE CONCEPTS WERE GENERATED INCLUDING:
DIRECT SHIFT FORK ACTUATION USING:
STEPPER MOTORS
HYDRAULICS / PNEUMATICS
SHIFT SHAFT CONTROL USING:
CABLES
STEPPER MOTOR
ACTUATION UTILIZING EXISTING ATV POWER
SELECTED CONCEPT:
BASED ON SEVERAL KEY LIMITATIONS (TIME, COST, RESOURCES, CUSTOMER SPECIFICATIONS) THE ACTUATION
OF THE SHIFT SHAFT BY PNEUMATICS IS THE FINAL DESIGN CONCEPT.
A DOUBLE ACTING PNEUMATIC CYLINDER WILL REPLACE THE INPUT OF THE RIDERS FOOT FORCE IN ROTATING THE SHIFT SHAFT. WITH AN AIR SUPPLY FROM A
SMALL AIR COMPRESSOR AND A LIGHTWEIGHT RESERVOIR AN ENDLESS POWER SUPPLY WILL BE PROVIDED. ELECTRONIC CONTROLS FOR THE SOLENOID VALVES
WILL BE INCORPORATED TO PROVIDE EFFICIENT AND RAPID SHIFTING.
PNEUMATIC CYLINDER
& SHIFT SHAFT ATTACHMENT
TRANSMISSION GEAR STACKS
SHIFT FORKS
FEA ANALYSIS:
FEA ANALYSIS OF THE CYLINDER / SHIFT SHAFT ATTACHMENT PIECE:
FACTOR OF SAFETY: 4.3
CYLINDER AIR SUPPLY REQUIREMENT:
BASED ON A REQUIRED SHIFTING TORQUE OF 150 IN-LB, AT A 1 INCH RADIUS:
→93 PSI IS THE MINIMUM AIR SUPPLY PRESSURE REQUIRED
PCB BOARD:
THIS PCB BOARD IS USED TO INCORPORATE:
THE MICROCONTROLLER
VARIOUS CIRCUITY (USED TO OBTAIN RPM DATA)
TO DRIVE THE SOLENOIDS TO SHIFT GEARS
RPM SENSOR:
THE ATV RPM SENSOR PRODUCES VOLTAGE SPIKES & VERIOUS FREQUENCIES DEPENDING ON THE RPM’S OF THE MOTOR.
THE ZENER DIODE IS USED TO FILTER LOW LEVEL NOISE, THUS ONLY HIGH VOLTAGE SPIKES (ABOVE 5.5V) ARE FED TO THE POWER FET WHICH IN TURN WILL SEND 3.3V SPIKES TO THE MSP430.
COMPONENT
PRESSURE RATING (PSI)
CYLINDER
250
VALVES
116
PRESSURE SWITCH
TANK
125
AIRLINE
115
MANIFOLD
1000
SOLENOID DRIVER:
THE OUTPUT FROM THE MSP430 TURNS ON THE BJT, DRIVING THE LED INSIDE THE OPTOISOLATOR.
THE LIGHT FROM THE LED TURNS ON THE PHOTO-TRANSISTOR WHICH IT IS COUPLED TO.
THE PHOTO-TRANSISTOR TURNS ON THE POWER MOSFET TO DRIVE A 12V PNEUMATIC SOLENOID VALVE.
THIS CIRCUIT ELECTRONICALLY ISOLATES THE 3.3V MSP430 FROM THE 12V SOLENOID VALVE
TESTING METHOD:
SHIFTING TIME: TEST BENCH USING MOMENTARY SWITCHES ON THE CYLINDER WITH AN OSCILLOSCOPE TO MEASURE THE SHIFTING TIME OF THE CYLINDER.
SYSTEM INTEGRATION: STATIONARY ATV TESTING TO VERIFY PERFORMANCE AND RELIABILITY.
DESIGN SPECIFICATIONS:
SPECIFICATION
UNITS OF MEASURE
IDEAL VALUE
ACTUAL VALUE
WEIGHT
lb.
< 7
6.5
SHIFT TIME
sec.
< 0.1
0.035
RESULTS / CONCLUSIONS:
PNEUMATICALLY CONTROLLED SHIFTING MECHANISMS OFFER A VIABLE SOLUTION TO MAINTAINING MANUAL TRANSMISSION ADVANTAGES WHILE PROVIDING THE ADVANTAGES OF AUTOMATIC SYSTEMS.
CONTAMINANTS ARE A CRITICAL RISK FOR ANY PNEUMATIC SYSTEM
THE USE OF EXSITING MECHANICAL ATV POWER IS AN ADVANTAGEOUS SOLUTION VERSUS SUPPLYING ALTERNATIVE POWER SOLUTIONS IF POWER REQUREMENTS ARE RELATIVELY LOW.
SHIFTING MECHANICS ARE DYNAMC – BASED ON THE TYPE OF ATV RIDING THE SHIFTING METHOD VARIES
ACKNOWLEDGEMENTS:
SPECIAL THANKS TO:
POLARIS INDUSTRIES
DR. JAMES TAYLOR
DR. DANIEL PHILIPS
DR. WAYNE WALTER
MECHANICAL ENGINEERING MACHINE SHOP PERSONNEL