College - Author 1
College of Engineering
Department - Author 1
Mechanical Engineering Department
Degree Name - Author 1
BS in Mechanical Engineering
College - Author 2
College of Engineering
Department - Author 2
Mechanical Engineering Department
Degree - Author 2
BS in Mechanical Engineering
College - Author 3
College of Engineering
Department - Author 3
Mechanical Engineering Department
Degree - Author 3
BS in Mechanical Engineering
Date
3-2020
Primary Advisor
John Fabijanic, College of Engineering, Mechanical Engineering Department
Abstract/Summary
The purpose of this project is to create a sensitivities tool and start an optimization tool to assist the Cal Poly SMV Team in designing their vehicle, developing a driving strategy for competition, and becoming a contender in endurance events. The development of a user-friendly vehicle simulation and design tool was proposed by Professor Joseph Mello who is the club’s advisor. The SMV Team competes in endurance events such as the Supermileage competition or the Shell Eco-marathon with the goal of achieving the best mileage possible.
This report will present the research that has been conducted to understand and define the problems this project attempts to solve. Included is information gained from customer interviews (members of SMV club and Professor Mello), existing simulation tools for vehicles such as GT-Suite and OptimumLap, and other relative findings pertaining to subjects like vehicle modeling and the Shell Eco-marathon competition. Two Masters theses are also explored due to their relevance in the design and simulation of the Cal Poly SMV’s prototype vehicles and other sources that cover topics like vehicle inertia and aerodynamic impacts on fuel efficiency are presented. The research also investigates how the world’s most fuel-efficient vehicle, the PAC car II, was developed and details the application of dynamic programming to find the optimum driving strategy.
After summarizing the customer’s wants and needs to include the most relevant and important topics, the scope of the project is defined and engineering specifications that the tools will have to meet for this project to be considered successful are established. The specifications are separated into functional and nonfunctional requirements as is the standard practice for software design. Several alternative options were generated as part of the concept prototype and their pros and cons were weighed using a decision matrix to develop the final design. Some of the topics under discussion include modeling the engine, optimization method, and system representation. A few initial concepts were integrated into part of the final design such as the overall GUI layout as well as the road load calculator.
For the final design of the simulation and design tool, a model of the vehicle is developed using higher level design parameters and the underlying physical principles governing vehicle performance. The sensitivities (design) tool investigates the effects of changing such parameters on the overall fuel consumption to help the SMV team optimize their design. The burn & coast optimization (simulation) tool attempts to find an ideal driving strategy that maximizes fuel-efficiency given a set of design inputs and track profile. It is to be noted that the burn & coast optimization tool is not completed in its entirety, but a detailed source of instruction to continue with the tool is provided. The end-user can operate the tools through an intuitive graphical user interface (GUI) that can easily be used by any Cal Poly student.
There are several spreadsheet tools and templates that interface with the simulation and design tool through the GUI which include the road load calculator, engine performance data, and track profile. The required operating software for the project includes MATLAB 2019b and Microsoft Excel which are both provided by the school and is free of charge for any Cal Poly student. The manufacturing and validation procedures are introduced along with detailed timelines to complete the project before the end of Winter quarter deadline. Part of the validation occurs simultaneously with the development of individual modules such that during the assembly and final production phase, all inputs and outputs have been verified and within an acceptable margin of error. The final product will be tested thoroughly and destructively to leave little room for user error and system crash. User manuals of the product are also available to the SMV team to account for any confusion while using the product. Finally, relevant literature is introduced as part of the appendices.
URL: https://digitalcommons.calpoly.edu/mesp/521
MATLAB Installer file