ECO Buggy

The EcoBuggy was created to provide all-terrain transportation with minimal environmental impact. A fun vehicle that is equally comfortable on both rocky trails on paved roads.

Design Overview:
Lightweight, aerodynamic bodywork to enable efficient high-speed cruising. Adjustable ride-height suspension allows either responsive on road handling or high-clearance, long travel for rough terrain. The chassis with integrated roll cage is strong and rigid for durability, handling, and safety. Aluminum and steel skid plates and tubular bumpers protect composite components from impact induced damage from rocks and under 10 mph collisions with other vehicles or fixed obstacles.

Propulsion:
Four independent hub motors electrically power the EcoBuggy. The hub motors' casings feature mounts for the disc brake calipers and hard points for suspension linkages. Energy is stored in lead acid batteries mounted on the floor providing a low center of gravity. The motor control unit delivers power independently to each wheel based on the grip of each wheel. The speed of each wheel is monitored several times per second. If one or more wheels begins to spin faster than the other wheels, power will be redirected to the slower wheels until all wheel speeds return to similar speeds. The speed sensors are also coupled with the braking system to redirect braking force away from a wheel that has locked up. The power proportioning system will not allow braking to be applied to a wheel that has braking force applied to it. To enable advanced driving techniques like trail braking; the system proportions power to the front wheels and braking to the rear if the brakes and throttle are simultaneously applied. The brakes are designed with a mechanical failsafe to ensure full braking capability despite loss of electrical power or CPU failure.

Chassis/body design:
The chassis and body are made from FRP to provide maximum strength and stiffness with minimum weight. It is designed to protect to occupants from both impacts with other vehicles and fixed off-road obstacles. The EcoBuggy’s body is partially integrated with the chassis to provide a semi-monocoque structure. Non-structural body parts like fenders help reduce aerodynamic drag allowing efficient, high-speed travel.

Suspension:
The suspension is fully adjustable to allow smooth, efficient travel over both pavement and unimproved trails. Two different variations are being considered. The first uses a mechanically adjustable geometry that changes effective spring and dampening stiffness based on selected ride height. The other option would be to use electric, pneumatic or hydraulic systems to independently vary ride height, dampening, and spring stiffness. These settings could be predefined profiles for standard conditions or user customizable for optimal performance. The mechanical system would be cheaper to build and more reliable however the advanced system would weigh less and would better accommodate rapidly changing trail conditions.