The most significant risks are the sensing distances of some of the sensors the team tested. For example, the LDR sensor has a sensing range of 30 cm, but objects are only detected if they are directly placed above it. For this reason, we will change the number of each type of sensor on our platform to address this issue as well as possible. Some of the sensors also are not able to distinguish between the materials we want them to (such as the capacitance sensor for paper vs. non-paper materials), so we will need to either research another sensor to use for certain materials, or adjust the scope of the recyclable categories as needed. Other sensors may not be able to be used as intended (i.e. LDR sensor can’t detect all types of glass), so we may also change the type of sensor used for certain recyclable categories (i.e. use capacitance sensor for glass). Our contingency plan for the limited sensing ranges includes purchasing more sensors if budget allows.
The number of some of the types of sensors was changed, and we will be changing the way some recyclable categories are detected. After testing, the IR sensor was determined to be useless for the purposes of this project, since it can’t distinguish between any of the recyclable categories, so we may be removing it entirely from our system spec. Changing the number of other kinds of sensors was also necessary because some sensors cannot be used to distinguish between certain recyclable categories as intended. For example, the LDR sensor only is able to detect clear glass, not colored glass, so we may use capacitance sensors instead to detect all types of glass. The costs to this change are monetary, since certain sensors like capacitance sensors are more expensive than other kinds of sensors. These costs will be mitigated with further analysis of our budget as we finalize the number of the sensors we will use for each sensor type for the bottom of our platform (which the object goes into).
Here is a picture of the setup we used to test the sensors (this was the capacitance sensor):
