Button Pressing Mechanism
Overview
Worked in a team of four to design, build, and control a complex linkage mechanism to press arcade buttons in sequence as quickly as possible. Each team are responsible for kinematic planning, creation of 3D model, manufacturing of linkage components, wiring, sensor usage, signal processing, transmission design, control system tuning, and actuation. At the end a competition is held to see which team's mechanism presses the most button in a minute.
How it works:
The playing field consists of three button pairs: red, blue, and yellow. Right above the red buttons there is a green button which is also called the bonus button. The buttons will light up for one minute in various orders and the button pressing mechanism will begin engaging onto the lighted buttons for that minute. Each time the button pressing mechanism presses onto any of the light-up button pairs the team will receive one point while pressing the bonus button the team will receive three points. Whichever team clicks the most button in a minute wins the competition.
My Role
Kinematic planning
Creation of 3D model
Wiring
Signal processing
Transmission design
Control system tuning
Actuation
Software
SolidWorks
Fusion 360
Arduino
Tools
Tormach 770
Lathe
Bandsaw
3-D Printer
Drill Press
Wires
Arduino Board
Team Members
Axel Oretga
Ryan Wu
Nicolai Dolinar
Timeframe
1 semester
Design Process
Linkage Selection
Each team member designed the size and placement of the coupler link to hold the acrylic piece (the material that is going to be pressed against the buttons on the playing field when a solenoid is attached to it) to determine whose system produce the best transmission angle. As a group we settled into the design shown on the left which produced transmission angles that are within 15 degrees of 90 degrees (ideal) throughout operations. Having transmission angle closer to 90 degrees when in operation would reduce the force needed to move the links by the motor which would induce in a faster button pressing mechanism.
Coupler Design
There are two slots opened for the placement of the solenoid on the coupler design so that the acrylic piece on the top can press the bonus button on the playing field. The slot on the bottom would allow the acrylic piece to engage onto the lower two buttons when the solenoid is powered. The solenoid on the top was is not necessary for this project since it is only for addition points (optional).
SolidWorks Assembly
Designed the input and output links with generative design study in Fusion360. Hardstops, acrylic button holder and acrylic piece, coupler, and spacers was designed in SolidWorks. All other parts was ordered through McMaster or given.
Transmission Design
Research and perform calculations to see what kind of gears should be ordered that would produce the most optimal transmission ratio for our mechanism. Also, determining the best placement of gears in our system for operation.
Machining
The ground plate alongside with the input and followers links are waterjetted. The coupler was made by using the Tormach machine while the spacers and hardstops was made by using the CNC lathe. All of the button pressing mechanism were 3-D printed.
Set-Up, Testing and Optimizing
Setting up the connection of the mechanism and revising code provided by the instructor to fit our system's need. Performing PID tuning, gravity compensation, and friction compensation to improve the performance of our mechanism.
A video demonstration shown on the right during PID tuning.
PID Tuning.movOutcome
Machine Design Final Video.mp4Points: 202