13.1 - Project Proposal

Introduction:

Windows are seen everywhere and we walk past them not thinking about how they get clean. Someone has to do the cleaning of the windows, but not everyone has the guts to do it. Our project offers to do this tedious task, on a much smaller scale at this point, so that we don’t have to worry about having dirty windows. This project interested us because we thought about what kind of motion this mechanism would have to cover every inch of the glass we chose to clean. We wanted to see how we could create a 1 DOF mechanism that can reach into corners to clean the surface properly. 

Problem Statement:

Currently, there is limited window-wiping technology available. It’s either windshield wipers that don't clean the entire window, or someone has the meticulous task of cleaning the window. We plan to create a robot that can clean windows in one single sweep without leaving any uncleaned residue. The path our mechanism will take must cover the entire surface of the window and even be able to reach into corners that are often forgotten. A combination of simple mechanisms will be necessary to achieve this goal. Recently, remote control Roomba-like robots have been made that clean windows. We plan to elevate this idea by making an automated robot so you can enjoy other activities while the cleaning gets done.

Proposed Mechanism:

In order to address our problem, we propose a slider crank mechanism with sponges attached at the ends of our links. A slider crank mechanism will allow the sponges to travel in circular motions to avoid any residual streaks that are left from side-to-side motions. The flexibility of sponges, as opposed to squeegees,  will help reach the corners of our window and apply more pressure to our glass surface. To automate this process we will attach a geared DC motor to our driving link to deliver low-speed and high-torque control of our system. By attaching our slider crank to a vertical slot mechanism, the slider crank will be able to move vertically while rotating around the window. To achieve this vertical movement we plan on either using a scissor lift, an archimedean spiral gear mechanism, or another slider crank that will move vertically as opposed to horizontally. All of these mechanisms are controlled by an input shaft that we will be able to automate using either a DC motor or a servo motor.

Proposed Scope:

1. Design and iterate linkage mechanisms for cleaning motion with dynamic pattern adjustability for different glass surface geometries
2. Develop mechanical designs considering sponge force, transmission efficiency and joint robustness.
3. Rapid prototype and CAD model linkages to validate sponge motion before production.
4. Construct preliminary functional prototype by leveraging manufacturing techniques such as 3D printing and laser cutting.
5. Implement a mechanism to control the pressure applied on the glass surface.
6. Finalize with machined components to improve performance and reliability of linkages and mounts.

Preliminary Design:

The mechanism above consists of a slider crank with a vertical slot attachment. As the slider crank rotates our slotted link will move vertically creating a figure eight. Two sponges will be attached to the slider crank giving us a greater surface area to clean.