Machine Design:
Rapid Robotic Button Presser
Project Description
Check out the SolidWorks model of this project on GrabCad!
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The Rapid Robotic Button Presser is a custom designed and fabricated linkage mechanism created as a team project for Columbia's Machine Design course. The objective for the course was to build and tune a machine to automatically press buttons on a playing board in a randomly generated order as quickly as possible. The team was given a $100 budget and evaluated on the playing score, mechanism volume, and transmission angle deviation.
I was responsible for kinematic planning, designing and creating the 3D model, and spearheaded much of the optimization efforts to reduce mechanism volume. I led the implementation of electronics and the development and tuning of the PID-based control algorithm to obtain the best performance from our mechanism. This effort included coming up with novel innovations in our control implementation with transition-based inertia compensation adjustments.
Methods
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Designed a four-bar linkage mechanism to hit sets of required buttons
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Optimized linkage to minimize transmission angle deviation using numerical optimization in Python
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Fabricated links, ground plate, and motor mount using CAM and CNC mills and lathes
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Selected transmission system via inertia matching to maximize linkage acceleration
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Designed mechanism joints with adequate bearings and lubrication to minimize friction losses
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Constructed circuitry for DC motor, solenoid, limit switches, motor drivers, MOSFETs, and encoders
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Tuned PID-control system and significantly boosted performance by introducing transition-based custom gains, smart velocity control, gravity compensation, friction compensation, and inertia compensation
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With a class average of 122 points, we achieved a score of 182
Media
Full Mechanism
Kinematic Planning Diagram
Solenoid-Actuated Button Pressing Mechanism
Mechanism Joint Design
