matv memorial university all terrain vehicle team members jonathan cole trevor dwyer fabio faragalli

MATVMATVMemorial UniversityMemorial UniversityAll Terrain VehicleAll Terrain Vehicle

Team membersTeam membersJonathan Cole Jonathan Cole

Trevor DwyerTrevor Dwyer

Fabio FaragalliFabio Faragalli

Project OverviewProject Overview

• Design an autonomous amphibious vehicle able to navigate rough terrain

• Allow for the attachment of components for navigation, automation, and various future endeavors

• Improve upon the design of existing competitors vehicles that have inherent design weaknesses

Project DeliverablesProject Deliverables

• Design and fabrication of one complete hydraulically powered wheel assembly

• Design and fabricate a closed hydraulic system to support driven wheels

• Design and fabricate robust offroad suspension for vehicle

• Design and fabricate amphibious platform to support vehicle automation equipment and payload

Design SpecificationsDesign Specifications

• 6 wheel vehicle/platform• Hydraulically driven • Amphibious• Must have enough torque to climb a vertical wall• 50 lbs pay load• Less than 48” wide• 12-14” ground clearance• Weight less than 300 lbs• At least 2 cubic feet cargo space • 24 hour autonomy• Attains speed up to 30 km/hr

Hydraulic System Motor, Pump Hydraulic System Motor, Pump & Engine Sizing Example& Engine Sizing Example

• Powered by 6 hydraulic wheel motors• One pump per side, powering 3 hydraulic wheel motors

each - in series• Gas powered internal combustion engine, governed at

3600rpm used to run pumps• Employs a closed loop, bi-directional hydraulic

transmission (reversible pumps)

Specifications:Specifications:

System DiagramSystem Diagram

Hydraulic Motors

Tank

Radiator

Filter

ReliefValve

CheckValvesReversible

Pump

Engine

CheckValves

Q

Sizing AssumptionsSizing Assumptions

• 2 front wheels have enough torque to lift ½ the weight up a vertical wall

• 3000psi operating pressure• Hydraulic motors in series – equal pressure drop• MATV Weight 300lbs• Wheel diameter 0.3m• Efficiencies all assumed η = 0.9• Max speed 30 km/h• Engine governed at 3600rpm

Required Wheel TorqueRequired Wheel Torque

• Fg = (300lbs)(1/2 weight)(1kg/2.2lbs)(9.81m/s^2)• Fr = (Fg)(Sin30 °)• Tr = (Fr)(0.3m)

• Tr = 50.2 N·m

30°

Fr

Fg

D = 0.3m• 1 wheel schematic• Use ½ weight

Sizing Motor DisplacementSizing Motor Displacement

• Tr = (Dm)(P)(ηmm)• Dm = (50.2 N·m) / (6.89x10^6 N/m^2)(0.9)

• Dm = 8.1x10^-6 m^3/rad• Dm = 3.1 in^3/rev

1000psi (per motor)

Sizing Motor FlowrateSizing Motor Flowrate

• Vmax = (30km/h)(1000m/km)(1h/3600s)• V = (ωm)(π)(0.3m)• ωm = 8.84 rev/s

• Qm = (ωm)(Dp) / (ηvm)

• Qm = 4.9x10^-4 m^3/s• Qm = 29.5 L/min

Sizing Pump DisplacementSizing Pump Displacement

• Qp = Qm (Series) – Pump flowrate• Qp = (ωp)(Dp) / (ηvp)

• Dp = (4.9x10-4 m^3/s) / (3600 rev/min)(1min/60sec)(0.9)• Dp = 9.1x10^-6 m^3/rev• Dp = 9.1 cm^3/rev• Dp = 0.55 in^3/rev

Hydraulic pump specificationsHydraulic pump specifications

• Pump type 3070• Nominal Delivery: 32 L/min (29.5 L/min Required)• Displacement: 21.33 cm3/ rev (9.1 cm3/ rev Required)• Maximum Continuous Pressure 3000 Psi• Speed at Maximum Continuous Pressure 3000 rpm

Engine SizingEngine Sizing

• Rolling Resistance• Assume 10% of operating pressure (300psi)

• Tp = (9.1x10^-6 m^3/rev)(1 rev/2π rad)(2.068x10^6 N/m^3) / (0.9)• Tp = 3.33 N·m

• Engine Power• Power = (Tp)(3600 rev/min)(1min/60sec)(2π rad/1 rev)• Power = 1255W• Power = 1.7 HP

• Engine runs 2 pumps• Power = 3.4 HP

Dp300psi

Selected Engine SpecificationsSelected Engine Specifications

• Air-cooled, 4-Stroke, OHV, single cylinder

• Displacement: 163 cm3 (9.9 cu in) • Net horse power output: 3.6kW

(4.8HP) at 3,600 rpm

• Net torque:10.3 Nm (7.6 lbs ft) at

2,500 rpm

Selected Engine SpecificationsSelected Engine Specifications

• Starting system: Electric Starter• Oil Capacity: 0.6 liter (0.63 US qt)• Dry weight: 13.0 kg (28.7 lbs)• Dimensions: 12.0 in x 13.4 in x 12.5 in• Fuel tank capacity: 3.1 liter (3.3 US qt) • Requires 1.26 Qt/h fuel

Required Fuel ReservesRequired Fuel Reserves

• Engine requires 1.26 Qt/h• 24h Automation

• R = (24h)(1.26 Qt/h)(0.946352 L/Qt)

• R = 28.6 L

• Design for 32 L (10% reserve)• Modified tank required

Suspension Suspension

• Double A-arm suspension chosen

• Upper a-arm shock mount chosen– More clearance for

hydraulic motors

• Allows for maximum suspension travel and ground clearance in offroad environments

Existing CompetitionExisting Competition

Frontline Robotics

Foster Miller

Gantt ChartGantt ChartMATV Project Management Plan

7-Jan-10 27-Jan-10 16-Feb-10 8-Mar-10 28-Mar-10 17-Apr-10

Kickoff Meeting

Webpage Design

Research

Project Presentation 1

System Sizing

Component Selection

Design

Mini Report 1

Parts Ordering

Project Presentation 2

Fabrication

Mini Report 2

Testing

Final Presentation

Final Report

Questions!!!