1. MATV Memorial University All Terrain Vehicle
Team members
Jonathan Cole
Trevor Dwyer
Fabio Faragalli

2. Project 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

3. Project 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

4. Design 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

5. Hydraulic System Motor, Pump & Engine Sizing Example
Specifications:
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)

6. System Diagram Q Tank Radiator Filter Hydraulic Motors Relief Valve
Engine
Check
Valves
Check
Valves
Reversible
Pump

7. Sizing 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

8. Required Wheel Torque Fg = (300lbs)(1/2 weight)(1kg/2.2lbs)(9.81m/s^2)
1 wheel schematic
Use ½ weight
D = 0.3m Fr Fg
30°
Fg = (300lbs)(1/2 weight)(1kg/2.2lbs)(9.81m/s^2)
Fr = (Fg)(Sin30 °)
Tr = (Fr)(0.3m)
Tr = 50.2 N·m

9. Sizing Motor Displacement
1000psi (per motor)
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

10. Sizing 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

11. Sizing 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

12. Hydraulic pump specifications
Pump type 3070
Nominal Delivery: 32 L/min (29.5 L/min Required)
Displacement: cm3/ rev (9.1 cm3/ rev Required)
Maximum Continuous Pressure 3000 Psi
Speed at Maximum Continuous Pressure 3000 rpm

13. Engine 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
300psi Dp

14. Selected 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

15. Selected 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

16. Required Fuel Reserves
Engine requires 1.26 Qt/h
24h Automation
R = (24h)(1.26 Qt/h)( L/Qt)
R = 28.6 L
Design for 32 L (10% reserve)
Modified tank required

17. 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

18. Existing Competition
Frontline Robotics
Foster Miller

19. Gantt Chart

20. Questions!!!