Fall Outcome

The final design concept was designed to take into account all the following features:

Durable

Cheap to Manufacture

Easy Component Replacement

Easy Connections w/ gloves

Cold Weather Functionality

Waterproof

1 Step Deploy-ability

Component Versatility

Light

Small

Variety of Terrain

Stable in Bad Weather

Accuracy of Snow Depth

•  The stand design was modified from the original design to sustain it's integrity in 50mph winds.  The simulation videos can be seen on the Concept Comparison link.  It was found that the thickness of the walls of the original design had to be increased in order to meet the 50 mph wind requirement without having any contortion.
• The cost of manufacturing is zero because all parts are able to be manufactured by Katie and Tom.  

• All sensors that may break in the cold weather will be easy to replace because of the snap together connectors.  These connectors are made for underwater use and will withstand the cold weather conditions.  This way the replacement of parts is quick and easy while wearing gloves but also waterproof. 

• All the parts in the power system were made to operate at -50 to -40 degrees Celsius.  The stand was simulated to test it's integrity under these same conditions.
• The power system is waterproofed by using 2 Pelican cases.  This case brand is designed to allow air flow but block out moisture from penetrating.  Since there will be a need to drill holes in the case to allow i/o wires, there are water proof plugs that will allow the wires to run in and out without letting in moisture.  One case will protect the batteries and low voltage cut off, while the other will protect the Brain.  
• The 1 Step Deploy-ability was not met in order to allow for light weight and easy transportation since the entire metal structure stands 8 feet high.  The stand is made to snap together easily, but there is digging involved to bury the batteries and the anchoring system; this was acceptable to the consumer.   Compared to the current snow pillow technology, the SnowMAN is much lighter and compact; this makes it much easier to deploy by a small team.  
• The component versatility is met, to some degree.  The power source voltage was lowered to save money, but can be replaced by a larger source if needed for certain sensors.  Depending on the application, the user can change the sensors as needed.  
• The new stand design eliminated some excess parts making it a lighter design.  It also helped with lowering the expense by 60%.  The A123 batteries are much lighter than the original sealed lead acid battery.  
• The final design is more stable than the original tripod design.  An anchoring system was designed to stabilize the structure during storms.  The solar panel placement was moved to the top of the stand, from half way up, to allow for more sun exposure.  
• The new stand design will ensure that for most cases, the sonar sensor which measures depth, won't get covered up by snow; the stand and height of the sensor will allow for an accurate snow depth measurement.  
• This design was designed for a specific site with specific terrain.  It was decided that it was better to focus on making the brain box versatile instead of the stand design.  The brain box was designed to operate with in a range of voltages to allow substituting senors.  Different senors run at different operating voltages and the brain box operates in a range that covers most technologies.  
  

Final Design Concept

Full Stand Design                                    Zoom Solar Panel and Brain Box
Above is the final concept stand design with a close up of the solar panel and brain box orientation.  The tripod design was eliminated due to expense and height.  The design wasn't tall or stable enough to avoid being buried in a storm.  The design was also expensive due to the connectors at each connection point.  This final design has less connection points and the connectors are less expensive.  The solar panel is 3 feet higher than the previous design and the Brain Box is 1 foot higher than previously.  The current design will be lighter due to the use of less material.  There is some digging involved, but this was acceptable to the user.  The solar panel is positioned on a hinge in order to adapt the orientation to the most exposure for sun.  This will also allow for a future adjustment of a spring design to dissipate heavy snow on the solar panel.  


Below is the full power systems schematic and the low voltage cut off circuit.  The full power system consists of three A123 batteries (Li Ion Nanophosphate technology), the Brain Box (previously designed), the Low Voltage Cut Off and the solar panel.  
There is a balancing circuit which consists of a zener diode and resistor to make the batteries all charge at the same rate.  The 10W solar panel is used to trickle charge the batteries; the LVCO is in place to protect the batteries from draining too low.  If the batteries discharge below 1.5 V each, then they will not recharge fully again.  
The LVCO consists of a relay that is tripped when the voltage drops too low.  This will cut the power to the brain box and allow the batteries to charge up only.  

Power System Schematic                                           LVCO Schematic
Click on LVCO picture to see enlarged view.


To View the Spring Charter, click Here.

 

Katie Gallo          kgallo@uvm.edu
Tom Lanagan     tlanagan@uvm.edu