For my senior design project, I joined RamBOTs. RamBOTs is a four-year robotics project with collaborators across many disciplines of engineering. With two electrical engineers, four computer engineers, three mechanical engineers, and three Vertically Integrated Project (VIP) members, the RamBOTs team is ready to advance the design and functionality of a quadrupedal robot, affectionately named Sparky. To be able to walk, dance, and more, Sparky incorporates technologies like inverse kinematics, sensor fusion, embedded programming, safety-focused power distribution, and machine learning. Our team aims to enrich our own education and hands-on experience while collaborating with Electrical and Computer Engineering (ECE) Outreach to inspire future engineers through an exciting and engaging project.Â
This year RamBOTs has more mechanical engineering members than ever before so that we can achieve our ambitious goals for Sparky. The goal is to mount a robotic arm on top of Sparky so we can have it play fetch and pick up objects.
With my team, we started designing using the engineering design process to make decisions and justify them. We created decision matrices to help choose important factors about the arm like what type of motors to use, materials to use, how to make it look, and how to power it.
We decided on using servo motors for their strength, cost, and position control. We also decided to fabricate the arm out of PETG, since it is lightweight, durable, and easy to manufacture. With these decisions, we started designing.
I made a Matlab script that you could input the lengths of each link and approximate dimensions of the links to find the weights of them, which is used to find the torque at each motor so we knew what motors to design around.
Full arm assembly, I made the base, while my teammates made the rest.
The base swivel works by a stepper motor driving the outer gear on a lazy Susan bearing with a 5:1 gear reduction
This is the housing that the big servo will sit on and hides the stepper motor driving its turning.
We've made lots of progress printing everything and will start to assemble and test soon!
I made this test circuit and code as a proof of concept prototype. It allows the user to input an angle they want the base to move and accounting for the gear ratio it will turn it.