Project Portfolio

Adjustable Test SKU

Berkshire Grey

Background

I was asked by the quality engineers on my team to develop an adjustable test SKU (stock keeping unit). The Robotic Put Wall team had always kept random items and SKUs of different heights and weight in storage. My task was to bring a prototype through the design process, with the goal of having a single adjustable SKU that the quality could implement during various test plans. The only strict design constraint was that the length and width dimensions of the test SKU had to be the maximum possible dimensions that could fit in a shelving unit (12" x 16").

Process

I first approached this project by designing a proof-of-concept extender in SolidWorks that could be used to adjust the height of the test SKU. The concept was 3D printed, and I was satisfied with the overall design choices I had made. I then went through an iterative prototyping process to incrementally solidify the design of the extender assembly. These changes included updating geometries and tolerances for ideal fits, revising part dimensions to accommodate shelving subsystem updates, and adding features for height-locking hardware. I decided to use heat-set threaded inserts and flat head screws for height-locking. I designed and laser cut acrylic sheets for the top and bottom panels of the test SKU, with cutouts to reduce weight while maintaining structural stability.

After assembling this first iteration of my design, I spent some time testing it to evaluate any potential design improvements. It became clear that using screws to set the height was a very time-intensive and tedious task. I redesigned the extender parts to use cotter and clevis pins to help ease the adjusting procedure. Another thing I wanted to improve was keeping the parts captive with each other, instead of being free to slide outside the limits of their positions. So, I designed in slots & set screw features to achieve this. Lastly, the extender assemblies themselves had coarse adjustments of 0.5", so I designed 0.1" acrylic "adders" to increase resolution.

Throughout this design process, I led design review meetings with the mechanical members on my team for feedback and mentorship.

Outcome

I designed two full iterations of an adjustable SKU that the quality team could use for various testing purposes. I was able to go through the full design process with this project, which was a valuable experience. When I presented the result to the quality team, they were very satisfied with the test SKU and appreciated the thoroughness of my work. They also pointed out that my change to the pins opened an opportunity in the future for them to add fixtures to the test SKU that would allow them to test adjusting the weight of the SKU. I completed this project as my co-op was wrapping up, but I know that the team was planning to use my prototype to test the new V3 shelving subsystem.

Skills Used/Developed

Group-4-Infomercial_1 - Trim.mp4

Smart Cane Attachment

Background

Course: Cornerstone of Engineering 1, Fall '21

Problem Statement: Blind people do not have much assistance navigating in urban environments. We wanted to design a simple product that could assist navigation by accommodating to a blind person's other senses.

Process

My role was to design the housing for the components and the mounting scheme to attach to the cane. Using SolidWorks, I modeled a clamp that uses four nuts and bolts to adhere to the cane. One side of the clamp has a dovetail joint, allowing the housing to slide on and off the clamp. A hole through the dovetail allows a pin to prevent the housing from sliding off. The housing is designed for simplicity: a 3D-printed box with slots and mounts for our components (switch, potentiometer, piezo buzzer, rumble motors, GPS, and an Arduino).

1st-year projects were given time constraints in the 3D-printing lab, which prevented us from being able to print the lid to the housing. So, I used AutoCAD to make a 2D drawing of the lid, along with dimensioned holes for an ultrasonic sensor, and laser cut from wood. This proved to be a sufficient alternative in terms of functionality, though not as aesthetically pleasing as 3D printing would have been.

Outcome

In the end, the project was very successful, as all the inputs and outputs worked together as desired. The only limiting factor was that, due to budget constraints, the GPS we ordered was not advanced enough to function consistently. Nevertheless, this experience greatly developed my foundations in common engineering prototyping skills, such as SolidWorks, laser cutting, 3D printing, AutoCAD, and basic programming.

Skills/Experience

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Martian Material Collector

Background

Course: Cornerstone of Engineering 2, Spring '22

Problem Statement: The theme for this project was to develop a device/product that could be used in future civilizations. Our problem statement was that humanity would need a device that can collect Martian material so that it can be processed.

Process

My role was to design a method for the rover to pick up a simulated Martian rock, which we modeled with a ping pong ball. The collection method I chose was a claw gripper mechanism, which I designed using SolidWorks. The claw mechanism needed to tilt up/down, as well as perform the closing motion. I realized that there would not be enough space for two separate servos to actuate each claw independently. So, I added gear teeth to the pivot end of each claw such that one servo could actuate the whole closing mechanism. The whole mechanism consists of two claws and two servos (grip actuation and tilt actuation), with all parts successfully 3D-printed.

To complete the project, another group member used their knowledge of computer vision to help program the rover. The rover searches for the orange ping pong ball, and once it is in frame, the wheels will turn the rover until the ball is straight ahead. Then, the rover will move forward within a specified distance from the ball and the gripping mechanism will activate. 

Outcome

This prototype worked surprisingly well, although there were some problems that could be addressed if a new iteration were pursued. First, we found that the ball tended to slip out of the gripper during travel. The simplest solution would be to add some material on the clamping faces to increase friction. Another major issue was the method of "seeing" the ball. The computer vision program simply looks for an orange hue, but we realized that there were some errors with that methodology when the rover would get confused with similar background colors.

Overall, this project was a very good final implementation of the fundamental engineering skills that I learned throughout my first-year engineering curriculum.

Skills/Experience

Mars Rover Arm Backlash Reduction

Background

Club: Northeastern University's Mars Rover Team (NURover), Fall '22 - Spring '23

Objective: The previous rover arm system had multiple gear stages in the axis that rotates the arm about the vertical with respect to the rover. These gear stages induced a significant amount of backlash, which introduced inaccuracy in arm control, as the arm could freely rotate a few degrees without any user input.

Process

My task was to devise a way to reduce the backlash in the Axis 1 subsystem. My teammate and I recalculated the force and torque required for the subsystem. We determined that the current subsystem's gearbox was over-engineered, since it produced significantly greater torque than needed, while inducing backlash in the axis. I designed a subassembly that used a Dynamixel M64T motor, which enables position and speed control, whereas the current motor required an encoder for the same functionality. In order to retrofit the design onto the existing rover frame, I designed a fixture of two plates that would interface the motor to the rover, as well as an adapter that allows a hex shaft to interface with the motor output head.

Skills/Experience

LIDAR Subsystem Attachment

Background

Club: Northeastern Unmanned Aerial Vehicles (NUAV), Spring '23

Objective: LISARD was a small indoor research drone that the club leads developed to serve as the main testing drone for the club. My task for this project was to design a way to attach LIDAR sensors to the bottom of the drone to allow for room mapping.

Process

I designed a "head" attachment, upon which 3 sensors could be screwed in using heat-set inserts. Incorporating a servo with a custom attachment, this LIDAR head could be rotated to provide 360-degree field-of-view. Using the CAD of the LISARD frame, I designed a servo housing that has mounting holes to allow our subassembly to attach to the underside of the LISARD drone.

Skill/Experience

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Basic Drone

Background

Club: Northeastern Unmanned Aerial Vehicles (NUAV), Fall '22 - Spring '23

Objective: At the beginning of the semester, the club leads wanted to provide a solid foundation of drone knowledge for the whole club. We were given a kit of wooden plates and several electronics, and we were tasked with assembling a basic but functional drone.

Process

I learned a lot about how drones fly and what each components' basic functions are. Through connecting electronic components, I gained experience with soldering and using a heat gun with heat shrink wire tubes. Additionally, I also got hands-on experience with various shop tools, like the drill press.

We had our flight test for the completed drone, and we were able to get it flying using an RC controller. While performing our flight test, we noted some properties of the drone's flight behavior. The drone was quite wobbly in the air, so we deduced that the 3D printed clamps were not dimensioned precisely, which would allow for unwanted rotation and flexure in the arms. Also, some of the controls were incorrectly mapped to the RC controller, so the drone would fly in the opposite direction along certain axes.

Skills/Experience