Blog #2 - Automatic Solar Powered Lawn Mower

Our problem statement and project goals were updated and are now more detailed, focusing primarily on reducing costs and operating sounds of the mower. Initially, the first problem statement and project goal(s) didn't have many specifications and they were not detailed at all. They just had general information about the type of mower we had envisioned which was not enough. 

Robotic lawn mowers are typically expensive, with models ranging from $600 up to $2800 with an average cost of a middle-of-the-pack mower being around $1770! We plan to make a fully automatic solar powered lawn mower that has an approximate cost of $500. This can be achievable by using parts and materials that don't cost nearly as much, but can still allow the mower to get the job done. This budget is also reasonable, since we do not plan on selling our model for a profit.

As far as operating sounds go, traditional gas powered lawn mowers output 80-90 dB and push electric lawn mowers output around 60-65 dB of "Harmful Noise Levels". We aim to have our mower have operating sounds of 60 dB or less. This will be tested and validated using a decibel meter while the mower is on and idle as well as while the mower is on and cutting grass.

Question 2:

The top 3 technical issues that we may run into later on is, fabricating the fully automatic function of the mower, being able to have the mower cut at a slope of up to 20 degrees, and a maintaining a mower run/operating time of 60 minutes.

By far, the hardest task/milestone is creating a lawn mower that can cut grass completely on his own. The only thing we would have to initiate, would be pressing a button or two to turn it on. This is achievable through many sensors and a through well written code. If we can't pull off the automation aspect of the mower, our backup would be to make it remote controlled. A controller would be used to control the movement, direction, and speed of the mower all while being able to sit on your backyard porch. Currently we haven't researched too much into RC components yet since we are primarily focusing on the automation part of the mower. 

Having the lawn mower able to cut up to 20 degree slopes may be a challenge when first testing our prototype out. For us to achieve this, there would need to be enough power supplied by the motors to push the mower up slopes up to 20 degrees and at the same time be able to cut the grass at those angles as well. 

Achieving a run/operating time of 60 minutes is doable if we complete the fabrication of the solar panel(s) that charge the batteries which then will power all the motors on the lawn mower. As long as there is enough sunlight, and the solar panels are functional, the only thing preventing or stopping the mower from running 60 minutes would be a faulty connection between the components or either the solar panel is not powerful enough to hold a charge to the batteries. 

Question 3:

Table 1: Prices of Current Automated Lawn Mowers (Taken from Amazon)

We created this table as a reference and comparison of current automated lawn mowers and their prices. It will be used in our papers and presentations as a way to show stakeholders that our lawn mower will cost significantly less than the average automated lawn mower. This chart is a good way for us as a group, later down the road when we are nearly done building and assembling, to look at and make sure we met our goal of staying within a budget of $500.

The block diagram above is a simple way to show parts and components and where they will be installed and utilized. We will need at least 3 motors to power various components of the mower. One of the motors will power the blades/wire which will cut the grass. Another motor will power the wheels which will allow the mower to move, and the last motor will power the sensors as well as the circuit board, which will allow the lawn mower to use GPS for its movement and automation. Once we find out more specific details of which motor and whether we will us a single blade, multiple blades, or even a wire like a weed trimmer to cut the grass, this block diagram will be updated.