Aprile 23, 2020

MAR – Multipurpose Amphibious Rover

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The need to operate through Rovers has emerged overwhelmingly in the last decade.
The Rover offers the advantage of avoiding human personnel exposure to the risks of the environment and often allows performance superior to the equivalent “manned” vehicle, since it does neither need the necessary space for man nor the consequent protective devices. The development of Rovers has had a significant evolution in the aeronautical sector, while today there are few innovative terrestrial or marine Rovers, and even less amphibian ones.

Principles of operation

Unmanned and amphibious, it can operate on sand, mud, liquid surface without changing shape or configuration.

The Rover is composed of two independent wheels, free to rotate around a central axis and two pendulums hinged on the same axis, each composed of arms and one or more motors. The electrical motors (or thermal engines) move, through a transmission system, the position of the pendulum, composed by the same engine and by the batteries (or tanks), thus generating a torque that makes the wheel move in the opposite direction.

The greater the weight of the pendulum and the more its center of gravity is far from the axis, the greater the thrust of the wheels. In this sense, negative elements, such as the weight of lead batteries, become positive elements as they increase the power of this propulsion system.

The system, given the low center of gravity, is intrinsically stable and able to recover the operating position even if subjected to overturning, a significant feature in an amphibious environment. The payload can be contained both in the lower part of the wheel, thus contributing to the weight of the pendulum, or in the upper part (of the wheel) if necessary due to the specific characteristics of the payload (eg: antennas or similar); in both cases the payload is protected. This does not mean though that the payload cannot be placed outside the wheels, as in the case of camera sensors or launch devices.

Main features

Intrinsically inexpensive. The Rover is structurally very simple and can be equipped with electric motors on the axles and lead batteries. In this configuration it can also be considered as “expendable”.

Amphibian. The wheels, equipped with blades and which can be built of plastic or composite material, act as floats and provide propulsion. The wheels themselves protect the payload from water, mud and the like.

High mobility. The Rover can go through all the trajectories, including rotating on itself at high speed, both on the center axis and pivoting on a wheel. The experiments made on the prototype demonstrate a strong acceleration capacity and a good maximum speed. The low center of gravity guarantees the ability to turn at high-speed or on significant slopes. The device also recovers overturning.

High reliability. Extremely simple construction ensures high reliability and the two-wheel modular structure simplifies logistics.

Intrinsically stable. Unlike other electronically stabilized two-wheeled vehicles, the vehicle is inherently stable and therefore does not require power consumption during standby. This allows its prolonged use while waiting for events. The Rover can also be equipped with a small thermal engine (thus creating a hybrid) that allows it to extend its operating capabilities over time and distance, without renouncing the advantages of the electric motor during the main operational phases.

High energy efficiency. The use of only two wheels, that combine propulsion and steering together, reduces friction and weight and guarantees greater autonomy compared to tracked or four-wheeled vehicles. At the same time, in an amphibious environment, it allows to keep the position stable, being able to direct the thrust;

Low footprint on the ground. The relationship between the weight of the Rover and its support surface ensures low pressure exerted on the ground.


Click here for the presentation of Amphibious Rover