Vibration Isolation System Project by: Monroe McCarty, Alex Mills, and Zachary Kamm ET - 493 Senior Design I Fall 2018 Instructor: Dr. Cris Koutsougeras Advisor: Dr. Ho-Hoon Lee

Introduction Vibration is undesirable in many systems and habitable spaces, and thus various methods have been developed to prevent the transfer of vibration to such systems. Vibration isolation is the process of isolating vibrations from an object such as a machine or a piece of equipment.

Objectives Design and build a prototype one-degree-of- freedom vibration isolation system to perform various vibration experiments. In this system, the vibration of various excitation frequencies will be generated by an unbalanced mass whose rotating speed will be controlled by using a DC motor. Design a motor controller to control the Dc motors rotational velocity.

System Functions The Vibration Isolation System is designed to do the following experiments: To determine the natural frequency of the vibration system by (1) counting the number of vibrations per given time and/or (2) by performing vibration tests over wide ranges of excitation frequencies. To investigate the effects of the damping and spring on the vibration transmission from the system to the system frame (the floor), which can be applied to the design of engine mounting in the auto industry. This can also be applied to the isolation of machines to another precision machine through the floor (the foundation)

Mechanical Design Required Materials Stainless Steel Aluminum Rollers Springs Dampers Rotating mass Arduino Board H-Bridge Drum Belt

Mechanical Design This vibration will be limited to vertical movement by placing the system inside of an enclosure with rollers on the four vertical sides Springs and dampers will be attached to the top of the primary mass and connected to the top of the enclosure for support and absorption The excitation frequency on the main mass will be controlled by controlling the speed of a DC motor rotating an unbalanced mass inside of it.

Arduino-based motor control system The motor control system consists of an H-bridge, a DC Motor, and an Arduino controller. The motor control system will be located inside of the main system where the rotating mass is installed. Arduino H-Bridge DC Motor

Arduino One Arduino micro-controller is used as a real-time control computer, which is connected to a laptop computer for programming. After testing, the motor control program will be uploaded to the Arduino controller.

H-Bridge Allows us to control the torque and thus the speed and rotational direction of the DC motor.

DC Motor The DC motor allows us to turn electric energy into rotational mechanical energy. It will be the source of energy for our rotating mass in the system We are going to have to find the right power and torque rating for our DC motor that we will use in this project

Timeline Proposal and Presentation September 2 – September 28 VIII. Timeline Timeline Proposal and Presentation September 2 – September 28 Study of Class Notes September 2 – November 3 Design of the mechanical system September 9 – November 30 H-Bridge circuit design and Arduino programming for motor speed control October 1 – November 30 Interim Report October 28-November 3 Presentations November 4 – November 30

Deliverables Design of the mechanical part of the vibration isolation system (Alex Mills and Monroe McCarty) including: Selection of masses Selection of springs and dampers Selection of an appropriate DC motor Design of an unbalanced rotating drum Design of a velocity control board with an H-Bridge and an Arduino microcontroller (Zachary Kamm) consisting of: A control circuit board including an H-Bridge for Arduino board. Arduino code to control the rotational velocity of a DC motor. Arduino code to quadruple the accuracy of encoder signals.

Works Cited Gani, A. “A LabVIEW Based Data Acquisition System for Vibration Monitoring and Analysis - IEEE Conference Publication.” An Introduction to Biometric Recognition - IEEE Journals & Magazine, ieeexplore.ieee.org/document/1033055/. Youngblood, Tim. “How To Control a DC Motor with an Arduino.” All About Circuits, 7 July 2015, www.allaboutcircuits.com/projects/control-a-motor-with-an- arduino/.