Author: jyw2

As we are finalizing our design, the most significant risk we are facing is figuring out how our system will handle the items that the model does not recognize. If the model is unsure about the item and cannot classify it, we weren’t sure if we should make the user retake the picture of the item for a more accurate result, or if we should have a rejecting system that will not place the item into any of the bins. We decided that we will place the item into the trash bin because it is safer to have something mislabeled as trash rather than contaminating the recycling bin with non-recyclable items.

Since we have switched from four categories of recycling, to just recycling and trash, we decided that having a sliding gantry was no longer necessary, and chose to go with just a single door that tilts right or left depending on what the item is sorted as. This change allows us to minimize the amount of time it takes for items to be placed into their respective categories, and reduces possible mistakes that could happen when placing the item. The cost of the change would also decrease the overall budget, as we would not have to purchase a gantry.

We are also planning to add a new system to our project, which is a game where the bin tracks the number of items recycled in a week, and compares it to the past week, as well as a running average of items recycled per week. This tracking system will work similarly to the setting in iOS that tracks weekly screen time, and serves to track overall recycling “performance” for the household. The statistics will be accessible through a display on the bin that connects to our Arduino. Users will be able to control the display with buttons to view different statistics (ie. this week’s total, average recycling per week, % of items in bins that were recycled).

Some pictures of running YOLOv7 off the shelf:

It works quite well for some images/objects, like this image provided in the repository

But not so well in detecting recyclable materials. Fine-tuning will be needed.

Part A-Ashley Ryu

With respect to considerations of public health, safety, and welfare, our project aims to address these aspects by encouraging better recycling habits. Public health is addressed by reducing waste and limiting exposure to hazardous substances, which can be caused by improper management of trash. Safety is addressed by educating users about proper recycling, and reducing the risk of people handling hazardous materials improperly. For example, batteries should be handled separately instead of going into the trash/recycling bin, because they contain toxic chemicals that may cause fire. Our project aims to identify these hazardous materials in addition to trash vs. recyclable. Lastly, we address welfare by promoting a sense of responsibility and awareness of environmental issues through better recycling practices.

Part B- Mandy Hu:

We intend for our project to impact society by making recycling a more prominent part of people’s daily lives. When doing research for our project, we compared recycling in America, where most people don’t care about it too much, to South Korea, where sorting recycling is normalized, and people who don’t recycle are looked down upon by society. By keeping track of recycling statistics, people will become more aware of how much trash they are consuming on a daily basis, and become more diligent about what products they are purchasing. In addition, by simplifying the recycling process and making it quick and easy, we want to make it so that even people who are busy don’t have an excuse to not recycle.

Part C – Justin Wang:

Since our project aims to be a household product, it should not be incredibly expensive. To that end, we are using mostly parts that can be purchased off-the-shelf and are easily accessible. The custom parts of the project are mostly software and system design, and thus can easily be replicated. The design aims to minimize complexity and parts required, which should reduce purchasing and production cost and make assembly easier. The bulk of the price will come from the Jetson, which does cost a significant amount, but the simplicity of the rest of the design should ensure a scalable production process that would make EcoSort easily accessible to those who want it.

A potential issue that was raised was the accuracy of a YOLO model, which tends to be used for applications where speed is more important than accuracy. We are currently looking into the possibility of more powerful object detection models, but are leaning towards a more recent version of YOLO, since it is easier to set up and run, and its wide use in past 18500 projects means that it is proven to work. Aside from the CV, a potential area of concern is the system to drop items into the bins. We’ve come up with an arrangement which should simplify the system as much as possible, with a linear gantry only requiring control to a stepper motor which will “select” a bin, and a servo to drop it in. In this way we avoid complex robot kinematics. If we end up switching to a single-stream system (more on that in the next paragraph), we will have only two categories, meaning the system could be further simplified.

Based on the feedback we received from our proposal presentation, we are considering changing our design to sorting into two bins, recyclable vs. trash, instead of four. Pittsburgh (and many other American cities) use single-stream recycling, which means all recyclable materials are collected together then sorted at the processing plant. Some places may collect sorted materials (ie. CMU has individual bins for different categories of recycling), but some places may simply collect our sorted materials and dump them together. Sorting into two bins will likely not have much impact on our computer vision system, which will still recognize and classify objects as we planned, the only difference being that classified objects will then be grouped based on whether or not they are recyclable, instead of the specific recyclable material (ie. water bottle → recyclable, rather than water bottle → plastic). There isn’t too much change on the hardware side, the system design will remain the same, only we have fewer categories. The biggest changes are in the mechanical design, primarily in part selection and physical size. With half as many categories, our bin can be physically smaller, and we can use a smaller gantry for item placing.

Since this change doesn’t impact the overall design of our project, we don’t anticipate our schedule to be impacted too much. This could have the potential to push back the hardware assembly part of the project, since we may be delayed in ordering the gantry, but we still have to go through the design process before starting assembly, so the delay should be small, if there is one.