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!!!