15.1 -- Project Proposal
Introduction.
Preparing breakfast or performing simple kitchen tasks can be surprisingly challenging for individuals with limited hand mobility, grip strength, or coordination issues. Even for people without those challenges, small repetitive tasks such as spreading butter or jam on toast can feel tedious, messy, and time-consuming during busy mornings.
Tackling this issue is interesting from an engineering perspective because it turns an everyday action that most people would not think twice about into a fun and technical challenge. It gives us a chance to combine design, sensors, and precise motion control through mechanism design to create something that appears simple but actually requires careful coordination. The final product would help people with limited hand movement complete their morning meals and be entertaining because it adds a creative and lighthearted side to engineering.
Problem Statement
Our project aims to create a compact automated buttering assistant that can handle these small but precise motions reliably and safely. The challenge lies in handling a soft, slippery object while maintaining smooth motion. This requires precise coordination between perception, motion, and force control. The robot must identify and approach the butter, grasp it gently yet securely, and transport it without deformation or slippage.
The motion and coordination profile involves both gross and fine control. The base must use smooth velocity profiles to approach the target. At the same time, the manipulator arm has to execute a controlled reach using a quadrilateral movement (either in rectangular or trapezoidal motion). Near contact, the arm must slow down for careful alignment and transition into compliant force control to ensure safe gripping. Further, the grips on the robot must apply a high enough force to grab the butter, but low enough so as not to deform or crush the butter
During transport, the robot must minimize jerk to prevent slip, keeping the arm near the torso for stability. Placement or hand-off requires real-time force feedback so the gripper can detect contact and release appropriately. The main complexity of this system is coordinating perception, motion, and compliance under uncertainties such as balancing strength, precision, and gentleness using low-cost hardware while maintaining safety and repeatability around humans.
Mechanism
The Mechanism that we’ve come up with thus far to solve the oval path of the arms of our robot that allow for the robot to lower its arms move them forward and scoop up whatever it intends to carry before lifting it and pull its arms back is a Geneva mechanism with the main wheel being a gear connected to a smaller gear below it that is on a vertical track. This setup would create the steady vertical motion of arms, while a slider crank mechanism attached to the main wheel of the Geneva mechanism would perform a simultaneous horizontal motion that would allow for this oval movement. Most of it is still theoretical as it is hard to mentally visualize any issues that would come with all the working parts, but it seems sound in theory. The degrees of freedom would be 1 according to the Gruebler equation of the mechanism, seen in the Preliminary Design Ideas section later.
Proposed scope
The scope of our project at the moment lies in creating either a simple wheeled robot or a fixed mechanism on a translating slide that has two mirrored scoop-mechanism arms and can precisely pick up and transport butter. While we have ambitions of making this robot either line-following or automated with sensors to scan the environment, detect the butter, then go and pick it up before returning to the user, our main focus for now will be in creating the mechanism that can accurately pick up the butter from the ground/plate without slippage and carry it back to the user.
Pre-fabrication analysis will include position analysis of the mechanism path to ensure that the robot’s arms can move from resting position down to the butter and back up to be served to the user. Additionally, Grashof check and transmission-angle range will have to be calculated once the mechanism reaches its final design. We must also determine the best strategy to go about clamping the butter to transport it, whether it be friction-based, using motors to translate the arms inward, having a scoop design, etc. Once this is completed and fully working, we will move on to the transport section of our project. Here, we will decide whether we have the capabilities and time constraints of putting our mechanism on a full wheeled robot or just a slider (that’s motorized or a separate slide-crank). Finally, if we get to the robotic scope of our project, we will have to code a program that drives our robot correctly and accurately via an Arduino. Some of us have experience with programming Arduinos, have access to UT makerspaces and have interest in autonomous robots, so if we were to extend the work of our project it would be in the direction of automating our bot to be fully functional and environment-intelligent with the press of a button.
Preliminary Design Ideas
Figure 1: Initial mechanism design for the arm of our butter-bot powered by one DC motor.
Figure 2: Idea and design inspiration from “butter-bot” on Rick and Morty, a tabletop robot who has existential dread after realizing its only purpose is to pass the butter to the user.
Figure 3: Alternative butter transporting mechanism if the robot portion of our project is too ambitious after we fully flush out the butter-grasping mechanism. A servo would be attached at the spine of the bot, allowing it to rotate 180 degrees for the user to grab the butter.