Balanced & Unbalanced Wheel Lab:

Abstract:

This lab aimed to model real-world systems as the transfer of energy. By breaking down energy into components like kinetic, potential energy, and work, including forces like friction and gravity, a model of two wheels with different sizes was created. The experiment used an optical encoder to track the angle and angular velocity of the large wheel in balanced and unbalanced scenarios. The change in angular velocity was estimated using the conservation of energy, kinematic relationships, and geometric constants. Four iterations of increasingly accurate models resulted in a mean residual of 0.08 and 0.13 for the balanced and unbalanced wheel scenarios, respectively. The most accurate models considered more complex effects such as friction and rotational energy, but adding unnecessary complexity, like modeling an extra mass as a rigid body, did not significantly improve results. Hence, it is important to find ways to increase model accuracy without adding unnecessary complexity.

Roller Coaster Lab:

Abstract:

Roller coasters play a significant role in the appeal of amusement and theme parks, offering a wide range of designs. In order to create a thrilling ride experience, it is crucial to consider elements such as novelty, speed, and G-forces. To achieve this, a comprehensive analytic model was developed to evaluate various design parameters of roller coasters. This model allows for the design of roller coasters that strike a balance between excitement and safety, and can be adapted to build coasters of varying intensity for any park.

Therapeutic Simon Says Game:

Abstract:

The Therapeutic Simon Says Game is an upgrade and new take on the existing Simon Says game style with an intent to be used for therapeutic use, particularly in pediatric use for children of special needs. Our client, Dr. Stefani Ruben, requested that we (Team Team) create a smaller, lighter, portable, and more robust prototype game system of an existing tool that she used. The original tool is shown in Fig. 2 and Team Team's final prototype is shown in Fig 1. The game is a derivative of the common Simon Says game with a few adjustments. In this system, each button is associated with a unique sound; when pressed in sequence, these sounds build a tune to be played back at the end of each game cycle. The system also has been adapted to make use of color changing RGB lights to improve user experience. With these changes, we intend to improve user attention and coordination skills as a result of using the product.

Background:

In working with our client, Dr. Ruben, we found that she uses the Simon Says game (Fig. 2) with the children she works with to train their focus and coordination. By memorizing patterns of lights and sounds, the children make use of both motor movement and mental focus to keep track of patterns and changes. The original system, however, was bulky and difficult to use; we were tasked with reducing size, weight, and increasing functionality.

Design Requirements:

• Less than 25 lbs

• Portable

• Access to internals

• Stronger enclosure

Design Process Overview:

​In creation of our final prototype, each person of the team was in "charge" of a specific design requirement or the projects underlying electrical/programming work. My job was to program the user (button) interface and design the circuits and PCB that would run the system. All code for this project, minus common libraries, was written custom for this project and the logic is visible in Fig. 3. This portion of the project was tag teamed by myself, who wrote the game logic and interface code, and Shree Vadayar, who worked on the sound interface with Spencer who wrote and performed all music. All of which had difficulties come up along the way; the buttons had to be de-bounced or they would not read properly, the lights refused to respond to 3.3v signals, and the audio had to be individually formatted to run. To run this system, we chose a Teensy 3.6 with a Teensy 3.0 Audio Shield for its lower price compared to other Arduino based micro controllers as well as its large assortment of pins (needed for the audio shield).

The circuit of the system was relatively simple. The Arduino and the audio shield were connected by a PCB (Fig. 4) that I designed to simplify the circuit design as well as to create easy solder points for the buttons and lights. The buttons and lights were daisy-chained from these solder points. For our lights, we used individually addressable RGB LEDs to minimize pin usage and allow for a simple circuit to control them from the code. The buttons were simple electrical switches that had connection points on the back and allowed for a light to be placed in the middle.

The chassis of the project were designed and assembled entirely by Luis Sanchez. The final CAD design can be seen in Fig 5. To successfully reduce weight and size, it was clear we couldn't use the same chassis materials that the original had. The original used plywood, which is cheap but bulky and not all that durable. To replace this, we decided acrylic would be better suited for the task as it is durable and lightweight. This material proved difficult to machine, but we eventually saw success with very specific settings on a laser cutter. To improve portability, a 3-D printed handle was placed atop the chassis. The design also includes a removable access panel on the backside as well as a metal stand. These chassis design changes attributed to a 50% weight reduction of about 15 pounds and a 40% size reduction (23" x 20" x 5" to 20" x 20" x 3.5").

In the final assembly of the project, we had difficulty sourcing parts and merging components of the project as a result of working around the COVID-19 pandemic. Some parts never arrived for assembly including one of the nine push buttons as well as the amplifier needed to play the sounds on a conventional speaker. For this reason, the project sits unfinished as of the final turn-in date.

Figure 1.

Testing:

By the design requirements we defined before beginning this project, the project was successful in meeting those requirements. System weight has been reduced by 50% from around 30 pounds to around 15 pounds. System size has been reduced by 40%, most of which is seen in the depth of the system (23" x 20" x 5" to 20" x 20" x 3.5"). System durability has been greatly increased by the strength of the materials used in it and it has a handle to improve portability. As a game, it also has increased functionality in the RGB lights which are used to indicate game win or loss scenarios.

​Conclusion:

Over the course of working with Team Team and creating this project, many lessons were learned and many skills were acquired. This is the first time I've ever created a purposed circuit or designed a PCB, and they were each a rabbit hole of new information. I thoroughly enjoyed my experience working with this group of people and I definitely learned something from each of them. Each person had their own skills and abilities and that's the big takeaway from this project; a well rounded group is essential to any design project.

Figure 2.

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Figure 5.