Model​​-Based Systems Quadruped

FAMU-FSU College of Engineering Senior Design - Team 505
Department of Mechanical Engineering

Our Project

FAMU – FSU’s robotics group aims to efficiently develop state-of-the-art legged robots. Previous robots have required costly, months-long development cycles. Getting all the parts together and doing initial testing has ended up taking multiple weeks. This led to issues arising from robot mass, motor sizing, and battery capacity. These issues have slowed down the design of each robot and CISCOR’s progress. 

We use a Model-Based Systems Engineering approach to expedite the design of four-legged robots. CISCOR focuses on four-legged robots that run, climb, and swim, so we designed a tool that can return critical parameters. These parameters include the mass distribution of the robot, the motor specifications, and other values. We use a combination of MathWorks products, including MATLAB, Simulink, and System Composer. These tools work together to accept performance specifications and return the previously mentioned critical parameters. 

For example, the user might want to build a robot that can climb at a certain speed for a specific amount of time. Our tool accepts these values and outputs critical targets like the stall torque and no-load speed. We chose these software packages because they have the capability to apply requirements. Using the previous example, our tool can run its analysis and see if the outputs produce a robot that meet the user’s needs. The user can also input the data collected from previous robots to update and improve our models. 

As more robots are built using our tool, their data can also be added. The goal is to reduce the uncertainty in design and time required to build and test the robot. The tool allows the user to be more confident in their design in a shorter time.   

The Team

Next Steps

The biggest improvement would come from the addition of more databases to reference. Within CISCOR, this could be adding RHex and Minitaur to the database but is not limited to robots that are already built. This would allow for more flexibility in future designs that could be produced by the program. On the note of flexibility, improving and updating the models would also play a large role. Initially we wanted to make it to implementing a Jacobian model, but that task became to big to truly finish the project with a functional tool in our time frame. The Jacobian would allow users to look at the impact that different leg types would have on a design, or different foot models for different gaits such as the difference between walking and swimming. 

The user interface could also be improved, not just from a graphics standpoint but from a functionality purpose as well. It is clear to us that it needs more error handling and fail safes in place for inputs that are truly unrealistic or unanticipated, and the inclusion of a status bar such as ones within CREO alerting the user if something does not make sense could also help streamline the process making it more efficient.

A more in-depth sensitivity analysis could also be put in place. We performed a high-level sensitivity analysis, specifically identifying how big of a role masses play within all the parameters, yet with increased model complexity additional variables could also be analyzed to see their impact more clearly within a design. 

Finally, being able to produce and choose a most optimal design would be significantly helpful. Ideally this would be rooted in the users’ goals from the tool, and could return what battery is most efficient, what leg length will be best, or what motor gives you the best outputs for the goal at hand. This would really take the tool to the next level in terms of assisting the user in getting the best results possible. 

Projected Timeline

Expo Demo Completion - Tuesday, April 4th 
Engineering Design Day - Thursday, April 6th 
Final Validation - Friday, April 14th 
CISCOR Acceptance - Friday, April 28th

Sponsors

Dr. Jonathon Clark

Sponsor

Dr. Patrick Hollis

Advisor

Dr. Shayne McConomy

Sponsor