By evaluating our final robot against the explicit requirements outlined, we can draw conclusions as to the effectiveness of our robot. Unfortunately, our linear actuators were incapable of supplying the speed required for our device to clean at the goal speed of 10 ft2/min. Because of this, our robot could not reach all areas of the window in the allotted three minutes for cleaning. Due to the limitation of the speed of our actuators, we opted to only clean half the window.
Despite only being able to clean some of the window, our robot provided very successful cleaning for the parts that it was able to reach. Any area over which the cleaning pads were dragged was always free of any marker when testing. Additionally, the cleaning pads soaked up all the moisture on the window, such that no residual moisture was left on the window surface. Thus, we were successful in the cleaning aspects of our robot.
Our robot also demonstrated the ability to cross horizontal and vertical barriers. While we opted to forgo barrier stepping in our demos due to lack of time, the capability was there for the device to successfully step over the barrier and continue cleaning on the other half of the window surface.
Additionally, our robot satisfied all the requirements for how it should be sized and operated. It did not exceed the 2 ft2 maximum area requirement, and it was easily portable; all that needed to be done to transport it was to utilize the quick-disconnect fittings to remove the tether. Also, the robot was run off of a dedicated power supply, and all the components required for its operation were either located on the tether or on the robot itself.
Our final robot demonstrates proof of concept for every single system requirement except speed of operation. When operating correctly, it is capable of successfully moving across the window in two degrees of freedom, providing successful cleaning, and crossing barriers.
Our major weak point is our lack of speed, which limits our ability to reach all areas of the window. However, because this is a fundamental limit of our actuators, we believe that our design concept is still sound. Faster actuators could be purchased and implemented with the same design concept, which would allow our robot to provide the same robust adherence to the surface as well as the same strong cleaning, but at a much higher speed.
Another weak point of our current design is its lack of robustness. We constantly had parts that were breaking or software that was malfunctioning, which would inhibit our robot’s ability to perform its desired function. The major factors for this were lack of time and lack of access to manufacturing equipment. For example, we consistently were shearing teeth on our laser-cut acrylic racks, a problem that could have been easily remedied if we had access to a waterjet that would allow us to manufacture aluminum racks.
Despite our final device’s shortcomings, we believe that with additional time, the design could be refined to a robust and successful window-washing design. The nature of our design causes it to be highly scalable; larger and faster actuators could be used for the linear actuators and the DC motors on the rack and pinion system. This would allow our robot to clean larger window surfaces in less time, and it would also allow it to cross over larger barriers. Additionally, the reliability of the vacuum-suction method makes our design resilient to the elements; the strong adherence to the window surface can resist things like rain and wind, common factors in an outdoor environment where our device would be located.