jdcsen Portfolio, projects, and other work by Joshua David Christensen

L3Dockerize: Python-based containerization tool

  • Python-based Docker container builder.
  • Dynamically resolves and fetches software component dependencies to build Docker images.
  • Intended to serve as a low/zero cost tool for developers to convert existing software installs to more easily monitorable, scalable, and extensible docker-based installations.
  • Concept evaluated in a system-wide CIT test of an L3Harris hardware product.

BUPDATE: Batch Updating tool

  • Python/Bash Scripting Toolkit for cross-project refactoring.
  • Uninvasive, agile solution to deal with problem of poorly-isolated dependencies impacting many components.
  • Core application written in Python, per-project scripts writable in any language.
  • Designed according to Unix ”simple, clear, modular, extensible” philosophy to facilitate integration into existing toolchains and processes.
  • Successfully deployed to automatically upgrade the dependencies of approx. 60 components without user intervention.

DRAGLINE: Dynamic RAcinG LINE

  • Augmented Reality Racing Line System running on an NVidia Jetson TX2.
  • Microservice-based architecture comprised of Python, C++, Javascript, and MySQL components.
  • Winner of 2019 Graduating Class Senior Design Competition.
  • Honors Thesis was an attempt at replacing L-BFGS-B Gradient Descent optimizer with a more reliable, machine-learning based approach.

Honors Undergraduate Thesis

  • Intended to provide a machine-learning based replacement for the L-BFGS-B gradient descent approach used by DRAGLINE
  • Evaluated the performance of simple feed-forward neural networks when tasked with predicting optimal paths through racecourses.
  • Provided the author an excuse to naively apply newly acquired machine-learning knowledge to a completely inappropriate problem.

Safety-Critical Power Control for a Fielded RF Front End

  • A new L3Harris radio needed far more output dynamic range than the fielded RF front end it had to work with was designed to give.
  • The front end’s transmit chain had two gain stages: a coarse driver with three setpoints (low, medium, high) and a downstream fine stage adjustable in dB. The radio commanded a single power level. I designed and implemented the control software that turns that level into a safe setpoint pair for both stages.
  • Reaching the required range meant disabling the equipment’s built-in protection interlocks, so the software became the only thing standing between a command and hardware damage. Both stages maxed, or either past its limit, could destroy the amplifier and drop a pilot’s radio link.
  • Acted as de-facto software lead: direction for a small team, and project status reporting to organization management.

Formula SAE Controls Team Lead

  • Led engineering teams to complete critical systems of a year-long engineering effort to develop an electric Formula race car.
  • Participated in and led design reviews for critical vehicle components.
  • Architected and implemented vehicle low-voltage systems, including safety circuits, vehicle networks, telemetry, and control.
  • Designed and built vehicle CCAs, working with EDA software (Eagle/KiCAD), from requirement collection to delivery.
  • Worked in close-knit, cross-functional teams to ensure effective and efficient concurrent development.