The Mud Season Challenge
UMaine Mechanical Engineering Capstone

April 30, 2016 UMaine University Forest
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  Autonomous vehicles that work and monitor the Maine woods present completely different  financial and practical constraints than those found in a large scale defense agency project in the desert. April in Maine provides some of the most uncertain and changeable terrain that a vehicle would encounter.  This competition focusses on systems designed for back country monitoring and  inspection of forests, agriculture operations and border integrity which must meet theunique financial and operational constraints encountered during a New England mud season.  


Budget for each group is $1400.  Each group must maintain a cost sheet to track all expenditure, as well as the retail cost of any materials found or donated.

Arduino must control speed of the vehicle through the motor, gears or other means.

The Arduino must control the direction of the vehicle though differential action (track steer) or with steering wheels.

Addition microprocessors, controllers or data loggers can be used for object detection and avoidance with the output being used as an input to the Arduino.

Start of the competition will be a staged start with an interval between vehicles which is deemed sufficient to minimize vehicle interference.

The vehicle should be no more than 3ft tall, with no more than a 3ft by 6ft footprint.  The weight is limited by practical considerations with significant benefits to a lighter vehicle, but under no circumstances should the vehicle exceed 200 lbs wet.

Time limit for completing the course is 30min.

There will be a pre-test before the competition to ensure design quality, drones must be able to move 100ft under their own power.

Two engines are offered, either a chainsaw or a standalone engine.  The engine may not be modified, other than the fuel delivery system. Link to chainsaw (ms211)  Link to standalone engine (predator 69733) Link to manual

A 12V 1.3Ahr battery or equivalent (24V .65Ahr, 6V 2.6Ahr) is acceptable for use.  The vehicles will not be able to complete the course without receiving additional power from the engine.  DC-DC converters can be used for 24V motors. Link to example battery Link to small 12V battery to be used in series as 24V.  Another small (9V, AA) battery may be used to power the arduino and data acquisition system to avoid noise.


Maximum fuel load is limited to 2 pints before being mixed with oil, with additional capacity either for separate oil supply or an increase in capacity for the volume of the oil mixed into the fuel.  Fuel will be contained in a fuel cell.  The throttle must be spring loaded and return to idle. Link to fuel cell (sum-290196)

Two emergency stop buttons are required on every vehicle, a remote stop and a 1 inch or larger red mushroom button on the top horizontal surface.  The vehicle mounted button must be at the highest point on the vehicle, clearly marked and surrounded by a red platform at least 4 inches in diameter.  The button must be located within 4 inches of the middle of the vehicle when viewed from above.  Both the remote stop and the local stop must stop the engine and all electrical supply to drive motors.  Remote stop needs a range of at least 50ft.  A chase vehicle will be used to ensure that it is always within range. Link to remote stop (Genssi RM02) Link to E-stop button (Baco LBX15301) Link to alternate E-stop button (Amico, must be painted yellow for contrast)

All drivetrain parts, including pulleys, sprockets, gears and other pinch points must be covered by a protective cover.

Maximum noise level under all operating conditions is 90dB with testing performed on a hard surface (asphalt or equivalent) at a distance of 20 feet with drive by with no reverberant surfaces within 100 ft.  SAE or other testing specifications to follow.

During operation a red flashing light of at least 500 lumens must be visible from all sides of the vehicle, with a forward facing white light of at least 700 lumen intensity. Link to sample lights

Maximum speed for the vehicle is 10mph.

All electrical connections should be adequately waterproofed, and wires should be fused according to wire gauge. The battery must be contained in an adequate battery box.


No moving water in the route will exceed 3m/s, depth will not exceed 2ft.  Maximum distance required to travel through water will be 50 ft.

Course length will be 1.2 miles, with 6 GPS checkpoints along the way.  GPS coordinates will be provides 12 hours in advance.

Maximum height of roots on the course will be 9in, and maximum height of rocks will be 1ft.  Maximum grade is 8%.

Drones will need to pick up a gunshot (or similar, >90dB) along the course, and record VGA or better quality at each of the GPS checkpoints.  At each of the GPS coordinates, there will be adequate room for the drone to turn around.

Self-starting engines are not required, and pull to start is strongly recommended.  

Revision No.    Date                 Revision By     Description                                                    

1.0                   9/1/15              M. Peterson    Created and issued rules

1.1                   9/15/15            N. Lawson      Updated and clarified rules

1.2                   9/17/15            N. Lawson      Updated water depth, added to safety

 1.3                   9/29/15           N. Lawson      Updated battery size

 1.4                 10/27/15           N. Lawson      Added option for 2nd battery for arduino

 1.5                 11/10/15           N. Lawson      Added option for equivalent batteries, and E-stop

1.6                 11/17/15           N. Lawson       Changed rules to cut electricity to engine coil, instead                                                                    of stopping fuel flow.

 1.7                   1/11/16           N. Lawson      Updated safety requirements and battery rules


The development of the University of Maine Mechanical Engineering Capstone is the results of more than two decades of efforts.  Starting with the efforts of a team of faculty at Colorado State University, a model for student quality and accountability was developed.  Based on this foundation the efforts began at the University of Maine in 2000.  The principles underlying this vision are at: UMaine Capstone Mission Statement.  Like any project with a sustainable competitive advantage the UMaine capstone emphasizes world class efforts with a clear sense of place.  

Michael "Mick" Peterson, Ph.D.