Pico : Assembly Line Automation Technologies
Battery Manufacturing at Alta Motors
Summer 2016 - Summer 2017
Alta Motors, based in San Francisco, CA, helped pioneer the high-performance electric dirt bike industry. I started as an intern and then continued to work with Alta as a consultant. I developed some the first mechatronic technologies required for the battery assembly line ramp to production and integrated those technologies into semi-automatic fixtures and smart tools.
Having never worked on a production line before, I needed to learn quickly. My supervisor and I agreed that my first project would be to study and document the current battery assembly process. Working with the technicians was fun, and the insights that they were able to provide proved invaluable throughout the rest of my time with Alta. The documentation I produced was released to the techs on tablets mounted to the assembly tables as a prototype interactive UI and helped to guide my projects.
When transitioning an assembly line designed for prototypes to production, it is critical to implement scalable infrastructure to keep up with increases in throughput. I developed three technologies to be used across the assembly line: wireless communication, proximity sensing, and sensed solenoid actuation.
WIFI ENABLED TOOLS
PROXIMITY SENSING
SOLENOID CONTROL
The low-cost wireless communication system piggybacks on the existing site-wide WiFi network and consists of workstation servers (Raspberry Pis) and hardware-integrated clients (Particle Photons). I developed a contactless and FOD resistant inductive proximity sensor based on the TI LDC0851 at a fraction of the cost of commercial alternatives. I prototyped solenoid drivers that use current profile monitoring and an IR breakbeat sensor to enable hardware interaction with redundant actuator sensing; later, I worked with an electrical engineer at the company to create a plug-and-play solenoid control board for accelerating future assembly line automation.
CURRENT PROFILE OF UNSUCCESSFUL FIRE
CURRENT PROFILE OF SUCCESSFUL FIRE
I used these technologies in several devices:
-
Wireless Bit Tray: A low-cost, smart drill bit tray that interfaced with the existing commercial process monitoring system
-
Smart Module Lift: An upgraded battery module lift that used integrated sensors to check for proper component mating
-
Swing Lock: An automatic lockout for the main battery pack assembly fixture to improve assembly safety and quality
-
Leak Tester: A prototype low-cost leak detector for qualifying the battery pack seals
-
Module Carrier Release: A smart fixture that uses pneumatic cylinders to release locks on the module assembly carrier once the battery module (which holds the cells) is complete
SWING LOCK MOUNTED TO BATTERY ASSEMLBY FIXTURE
SMART MODULE LIFT INDICATING SUCCESSFUL MATE
MODULE CARRIER RELEASE DEMO (WITHOUT MODULE)
I also developed a modular battery pack lift for safely moving the assembled battery pack (~40kg) from the assembly tables. The failsafe mechanism locks on to the mounting brackets that secure the battery pack to the bike, precisely positions the mounting brackets for assembly, and then uses those brackets to securely hold the pack. The dual function solved an issue that Alta was having where some battery packs did not fit on the bikes due to an under-constrained jig that pushed the assembly tolerances out of spec. The mechanism disengages with a simple hand-actuated lever on top of the lift.
PACK LIFT MOUNTED TO BATTERY PACK
PACK LIFT MECHANISM
The devices I worked on continued to be used at Alta as the battery assembly line was ramped up to production; they improved work holding, assembly quality and efficiency, operator safety, and component protection. The design approach that I took, creating modular building blocks that perform generalized functions and then building each device around these same building blocks, paid off and the technologies I developed as an intern and as a consultant continued to be used as Alta upgraded its production process. Unfortunately, due to financial concerns, Alta Motors ceased operations in October 2018 and has since largely sold off its assets.