# Joshua John L (Podalanga)

> Joshua John L (Podalanga): robotics and control-systems engineer. EPFL BioRob intern, NIT Trichy ICE, IIT Madras BS Data Science. Projects: ROS 2, LQR, MuJoCo.

Joshua John L, also known online as "Podalanga", is a robotics & control systems engineer. Tagline: "Observing Through Sensors, Controlling Through Censors, Tames the Chaos."

## Profile

- Name: Joshua John L (also: Joshua John, Podalanga, podalanga)
- Role: Robotics & Control Systems Engineer
- Education: B.Tech, Instrumentation & Control Engineering (Minor: Computer Applications), National Institute of Technology, Tiruchirappalli (Aug 2023 to Present)
- Education: BS, Data Science & Applications, Indian Institute of Technology Madras (Aug 2023 to Present)
- Research internship: BioRob, EPFL
- Website: https://podalanga.github.io/
- GitHub: https://github.com/podalanga
- LinkedIn: https://www.linkedin.com/in/joshuajohnl/

## Areas of expertise

Robotics, Control Systems, Control Engineering, Convex Optimization, Optimal Control, Linear Quadratic Regulator (LQR), Gain Scheduling, Pole Placement, PID Control, State Estimation, Sensor Fusion, IMU / Madgwick Filter, Observer Design, System Modeling, Kinematics and Dynamics, Inverted Pendulum, Mobile Robots, Differential Drive Robots, SLAM, LiDAR, Underwater Robotics, Remotely Operated Vehicles (ROV), Bio-inspired Robotics, Central Pattern Generators (CPG), Robotic Arms, Robot Simulation, Physics Simulation, ROS 2, MuJoCo, Gazebo, MATLAB, Simulink, Python, C++, Embedded Systems, Mechatronics, Computer Vision, OpenCV, Machine Learning, Data Science, SolidWorks, Mechanical Design, 3D Printing, Instrumentation and Control Engineering

## Projects

- [Mechanical Watch: Going Train and Swiss Lever Escapement](https://podalanga.github.io/projects/mechanical-watch/): The basic mechanism of a mechanical watch, from mainspring barrel to balance, designed from first principles: thirteen parts driven by 393 linked equations, ogival NIHS 20-30 teeth, a Monte Carlo tolerance study, and a full contact simulation that ticks at 0.2498 s against a design value of 0.2500 s. (Independent, AUG 2026 to SEP 2026; SolidWorks, SolidWorks Motion)
- [ZBot: Simulating a Zebrafish Larva's Bio-Inspired Locomotion](https://podalanga.github.io/projects/zbot/): Ported a bio-inspired zebrafish-larva swimming robot from Webots to MuJoCo/FARMS, then fixed two physics defects in the lab's underwater simulation stack: a fixed-point buoyancy model and a hard-coded fluid density. (BioRob, EPFL, JUN 2026 to AUG 2026; MuJoCo, Python, FARMS)
- [Trident AMR: Design and Simulation of a Differential-Drive Pick-and-Place Robot](https://podalanga.github.io/projects/trident-amr/): A 3D-printed differential-drive robot designed for a WorldSkills pick-and-place task: a caging gripper slides coins without lifting, RTAB-Map and Nav2 navigate around obstacles, and a line follower guides the final blind docking. 36 of 36 coins delivered across twelve simulated missions. (RMI, NIT Trichy, SEP 2025 to DEC 2025; ROS2, Gazebo, Nav2, RTAB-Map, SolidWorks, Python)
- [Designing a 3R Robotic Arm](https://podalanga.github.io/projects/3r-robotic-arm/): A minimal 3-degree-of-freedom revolute arm, designed for sequential hardware assembly rather than just simulation, with an anchored base and stainless-steel drive shaft. (NIT Trichy, AUG 2025 to SEP 2025; SolidWorks, onshape-to-robot, RViz2)
- [Data Collection and Mathematical Modeling of Wheelchair Dynamics](https://podalanga.github.io/projects/wheelchair-dynamics/): Derived a state-space model of wheelchair push dynamics from strain-gauge data collected across 40 subjects, and implemented a cruise-control proof of concept. (R2D2 / Thryv Mobility, IIT Madras, MAY 2025 to JUL 2025; MATLAB, Signal Processing)
- [Controller Implementation on a Rotary Inverted Pendulum](https://podalanga.github.io/projects/rotary-inverted-pendulum/): Linearized and stabilized a Quanser rotary inverted pendulum using pole placement, LQR, and gain-scheduled LQR, validated on real hardware. (NIT Trichy, DEC 2024 to PRESENT; MATLAB, Simulink, Quanser QUARC)
- [ROVIO: Simulation, Control and Vision-Based Autonomy for an Underwater Vehicle](https://podalanga.github.io/projects/rovio-underwater-rov/): RMI's eight-thruster, 6-DOF underwater vehicle: I sealed its enclosure, then built a simulated autonomy stack in Stonefish: thruster allocation, cascaded control, AprilTag localization and a monocular coral-mapping pipeline trained on auto-labelled images. (RMI, NIT Trichy, DEC 2024 to PRESENT; ROS2, Stonefish, Python, YOLO, AprilTag, OpenCV, SolidWorks, Blender, MeshLab)
- [Balancing Builder Bot](https://podalanga.github.io/projects/balancing-builder-bot/): A two-wheeled self-balancing robot with a gripper, simulated in CoppeliaSim: LQR-balanced while traversing a path and performing pick-and-place of foam boxes. (e-Yantra, IIT Bombay (RMI team), SEP 2024 to NOV 2024; CoppeliaSim, MATLAB, Python)
- [PLA Filament Extruder](https://podalanga.github.io/projects/pla-filament-extruder/): Rebuilt a filament extruder that recycles failed 3D prints and PLA support structures back into usable filament. (NIT Trichy, AUG 2023 to DEC 2023; Arduino, Heated Barrel-Screw Extrusion)

## Blog

- [Signal acquired](https://podalanga.github.io/blog/signal-acquired/): The first transmission from this site: what it is, why it looks the way it does, and what's coming.

## Optional

- [Full text of every project write-up](https://podalanga.github.io/llms-full.txt)
- [Photography archive](https://podalanga.github.io/archive/)
- [RSS feed](https://podalanga.github.io/rss.xml)