Next Steps

The group has created and simulated a completed CAD model of the design. To go along with the CAD models, technical analyses were done to determine the inputs and limits of the design. Through these calculations, the group has determined the required torque from the motors to rotate the conveyors, the minimal slope angle for the inclined conveyor, the electrical power required to operate the device, and the type of image processing required for the recognition system to function. The group has also gone on to create two physical alpha prototypes to better test the physical limits of the inclined conveyor and the functionality of the vibration plate. Through which, the team found the ideal physical angle of the include conveyor to be approximately fifteen degree and the vibration plate may need minor physical alterations to prevent clumping. Lastly, the group has created and maintained a website to document and record the progress made in the design process.

Through the semester, the group remained organized and completed all the tasks that were planned in the Gantt Chart. This includes the completion of the deliverables and the necessary steps in the design process to be approximately halfway through it. Next, the group will further test and create alpha prototypes and the CAD model to gain a better understanding of the physical aspects of the design. From there, the team will create beta prototypes until the sorting device design is finalized. In addition, the group will continue to update the website as the design process continues. Reaching the conclusion of Phase III, the team had gained a better understanding of the technical analysis and the construction of alpha prototypes.

Fabrication Plan

The first thing that needs to be done in the fabrication process of the beta prototype is to finish ordering all the parts. Some have been ordered, like the Pi 4 and some raw materials, but things like motors, actuators, and other smaller bits are either on their way or their part order is being finalized.

After this, the actual fabrication will begin. The fabrication will be split up into two main categories, physical and programming. The physical will start by going to the design lab to cut out the larger pieces necessary for the supports of the project, like the walls of the hopper and the stands for the vibration plates and sorter as well as the housing apparatus for the camera and lights in the recognizer. Next each sub assembly will be worked on separately, starting with the hopper, then the vibration plate, then the recognizer, and finally the sorter. For the hopper, the belt will be cut to the right size based on the length of the rollers and the distance needed to go between them, as well as placing ridges on the conveyor. Next, two rollers are going to be attached to the hopper and one motor to the TOP roller and then two plates will be placed along the path of the conveyor belt inside of it to make sure the belt stays flat. Then, the belt will be put on the conveyor, and finally, the LEGO stopping flap will be added to the bottom.

The vibration plate comes next. First, the v-shaped plate will be assembled from parts cut earlier during the fabrication of the supports. Then, the motors will be attached to the sides of the v-shaped plate. That is all that is necessary for the vibration plate.

Next is the recognizer. Two rollers will be connected to both sides of the recognizer supports with two plates going the length of the supports to make sure the conveyor belt stays flat, and then the conveyor belt will be put on the rollers. Then, a motor will be attached to the front roller. Next, the camera enclosure will be painted white and then the camera and lights will be put in place. Then the enclosure will be attached on top of the supports.

Lastly is the sorter. Similar to the last one, a conveyor belt system will be constructed first. Next, six rotating actuators will be placed along the sides of the sorting conveyor and an arm will be attached to each one of those. Then six containers will be attached along the side of the conveyor belt with three on each side and a final seventh at the end.

The last part of the physical fabrication process is connecting all the motors and actuators to the Pi4. After this, physical testing will need to be done to make slight modifications to the height of each sub-assembly to make sure they all work together with the LEGO pieces moving from each subassembly in an optimal manner. Additionally, testing will have to be done to determine the amount of power to be given to each motor, the swing distance of the sorting arms, the delay between when a part is recognized and when the sorting arm swings out, how long the sorting arm must stay out, if the conveyor belts will need to pause when going through the recognizer to ensure the computer correctly recognizes the LEGO part, and overall how to best optimize the timing to move a part through the machine.

The second part of the fabrication process is programming. Right now a framework for the code exists but it has to be adapted to recognize LEGO pieces. This will be done by taking many labelled images of each LEGO and using these as inputs for the neural network. The labelled images will allow the TensorFlow software to have data for each part. These images will serve as a benchmark for the software to draw conclusions as to what LEGO is being observed when it enters view of the camera. Once it has enough data and can recognize the parts on its own, the program will then determine which of the six categories it belongs to and tell the sorter which arm to move to sort the part. If the software fails to recognize the part, or the software assigns a category to the part that is outside of the range of the six categories, then the piece will be taken all the way down the belt to the final “unknown” category, which the team can consider to be the seventh and final category. The recognition will most likely take a lot of optimization and the bulk of the time for this phase.

Stevens Innovation Expo!

The BrickSort team has finalized our product design and are preparing for the Stevens Innovation Expo presentation! We hope that you join us at venue and support our continued efforts of delivering this product!

Zoom Meeting Link: https://stevens.zoom.us/j/92014212809