HI THERE I AM Sahasrajit Anantharamakrishnan

About Me

I am a dedicated graduate student in the MS Robotics program at Northeastern University, deeply engaged in cutting-edge research at the Northeastern Autonomy and Intelligence Laboratory. Under the guidance of Professor Michael Everett, I am spearheading a groundbreaking project on High Speed Off-road Autonomy, striving for self-driving capability in challenging terrains with a focus on safety. My journey in robotics began at thirteen, sparking a passion that led me to pursue a B.E. in Electronics and Communication. From winning competitions to internships at Capgemini and RigBetal Labs, I have honed my skills in robotics, project management, and innovative problem-solving. Notably, my Road Anomaly Detection System (R.A.D.S.) algorithm, designed for cost-effective road anomaly detection, earned me a full-time job offer. I thrive on solving complex problems, love learning, and excel in collaborative environments. With a knack for quick and efficient learning, I am poised to make significant contributions to the field of robotics through my enthusiasm, skills, and commitment to innovation. Here is a (not so small) history of me:

My fascination with robotics began at the age of thirteen when I participated in a summer robotics course. This experience exposed me to essential robotics concepts like Arduino programming, the theory and application of diverse sensors and actuators, and most importantly, ignited my enthusiasm to pursue a career as a robotics engineer.

This ambition shaped my academic path. Recognizing robotics is an amalgamation of Electrical, Mechanical, and Computer Science Engineering, I opted for a B.E. in Electronics and Communication at Anna University, Chennai. This path provided crucial knowledge in Control Systems, Communication Networks, and Embedded Systems - all pivotal for robotics.

In eighth grade, I engaged in robotics competitions at N.I.T. Calicut, sparking my passion. Despite setbacks, I learned crucial lessons in software and hardware optimization, leading to an 8.62% performance boost. This ignited the spark and love I have for competition and optimization. Freshman year in college I clinched victory at Roboprix 2019 held at V.I.T. Chennai in a high speed Robot racing competition.

During the 2020 pandemic, I completed a 5-month internship at Capgemini as a Robotics Intern, focusing on a ROS-based AUGIR (Autonomous Ultraviolet Germicidal IRradiation) mobile robot. This experience enhanced my project management and leadership skills in corporate R&D. Using Fusion 360, we modeled the robot in URDF and simulated it in Gazebo, implementing SLAM algorithms for navigation. I developed a proprietary algorithm for sanitation, utilizing ray-casting to generate navigation waypoints for efficient cleaning. In a project that didn't explicitly demand such innovation, creating this algorithm showcased my ability to think outside the box and reinforced my commitment to developing innovative solutions, reducing my inclination to accept things as-is. Additionally, this experience taught me to approach robotics projects from a more holistic system-level perspective.

Furthering my journey, I participated in eYRC 2020-21, delving into ROS MoveIt!, MQTT IoT, Computer Vision, and website development. In May 2021, I played a pivotal role in the open-source project iq_gnc, enhancing Ardupilot drone developers' capabilities through code conversion and setting up a robust CI pipeline. This experience fortified my commitment to innovation and collaboration in the field of robotics.

Beginning August 15th, 2021, I interned at RigBetal Labs LLP, as a ROS/Robotics Intern. My tasks included multi-robot mapping, cloud robotics, and Gazebo simulation with Blender. Building on past experience of creating novel algorithms, I crafted the Road Anomaly Detection System (R.A.D.S.) algorithm. This algorithm was designed for detecting road anomalies such as potholes, employs surface normal analysis and clustering. It determines surface normal at each point using normal estimation and identifies the common normal via RANSAC. A clustering algorithm then groups points with deviating normal, facilitating effective road anomaly detection.

This project's novelty and success garnered me a full-time job offer. Notably, prompted by the client's request for a more budget-friendly solution than the initially costly 3D LiDAR, I proposed a cost-effective alternative: employing a rotating 2D LiDAR to emulate a 3D LiDAR. This innovation significantly reduced costs while preserving system efficiency and accuracy, underscoring my practical problem-solving abilities in the realm of robotics.

Education

September 2022 - May 2024

Northeastern University

Master of Science Robotics Engineering. GPA: 3.939

Courses taken:

  • EECE 7398 - Legged Robotics
  • EECE 7323 - Numerical Optimization Methods
  • MATH 7233 - Graph Theory
  • EECE 7150 - Autonomous Field Robotics (Audit)
  • ME 5250 - Robot Mechanics and Control
  • EECE 5550 - Mobile Robotics
  • CS 7150 - Deep Learning (Audit)
  • EECE 5639 - Computer Vision
  • CS 5180 - Reinforcement Learning and Decision Making
  • EECE 5554 - Robotics Sensing and Navigation
June 2018 - May 2022

Anna University

Bachelor of Engineering in Electrical and Electronics Engineering CGPA: 8.66/10.00

Noteworthy Courses taken:

  • Robotics and Machine Vision Systems
  • Control Systems
  • Data structures
  • Embedded Systems
  • Digital Signal Processing

Work Experience

May 2024 - Present

Robotics and Intelligent Vehicles Research Laboratory (RIVeR)

Robotics Research Assistant

Project: Stochastic Model Predictive Control for bipedal loco-manipulation

  • Introduced probabilistic models into traditional MPC to create Stochastic MPC (SMPC), to improve adaptability and robustness against uneven terrain and unexpected loads
  • Spearheaded the adaptation of the SMPC framework from quadrupedal to bipedal robots to demonstrate its generalizability, using simulation platforms such as PyBullet and Gazebo
  • Refined the dynamics model and cost function to satisfy the constraints of the bipedal robot to guarantee stability
January 2023 - May 2024

Northeastern Autonomy and Intelligence Laboratory (NAIL)

Robotics Research Assistant

Project: High Speed Offroad Autonomy

  • Developed an innovative 2.5D terrain model accommodating uncertainties in both the shape and properties of challenging off-road environment
  • Created and Optimized a custom MPPI algorithm using JAX python, slashing average run time from 1000 ms to 1 ms
  • Crafted a custom cost function for MPPI controls, prioritizing speed in unstructured environments while considering the robot's kino-dynamics, terrain traversability, and safety constraints
  • Fine-tuned STEGO, a self-supervised semantic segmentation head for DINOv1 vision transformer, on RUGD, RELLIS, and a custom dataset to achieve clear class clusters for RGB image semantic segmentation
  • Employed sensor fusion techniques to combine 3D-LiDAR data with semantically segmented RGB images, resulting in a Semantic Point Cloud, essential for downstream perception, control, and motion planning tasks
  • Utilized Fusion 360 to engineer and assemble a customized compute and sensor suite payload, designed to meet the distinct needs of AgileX's scout and Clearpath's Warthog robotic platforms, to enable high-speed offroad autonomy capability
August 2021 - November 2021

Rigbetal Labs LLP

Robotics Engineer, Intern
  • Formulated a novel algorithm, Road Anomaly Detection System (RADS), in C++ to detect road anomalies (Potholes, Speed Bumps, etc.) using normal estimation
  • Reduced cost by 90\%, by generating a 3D Point cloud from a series of moving 2D Laser scans
  • Simulated a multi-agent (robot) mapping environment in Gazebo ROS to create a cohesive 2D map
    • Deployed the same in a cloud environment using AWS Robomaker to enable remote multi-user control of an agents
July 2020 - December 2020

Capgemini Technologies Services

Robotics (Medical Devices), Intern
  • Fabricated a ROS-based autonomous ground vehicle in Fusion 360 to sterilize and sanitize offices from SARS-COV2 virus with Ultraviolet (UV-C) irradiation
  • Directed communication and task distribution between the team and clients, enhancing team efficiency and client relations.

Languages and Libraries

  • Python
  • PyTorch
  • C++
  • C
  • Matlab
  • OpenCV
  • Point Cloud Library
  • Tensorflow
  • Lua

Software and Tools

  • ROS 1 & 2
  • Ubuntu (Linux)
  • Git
  • CMake
  • LaTeX
  • Docker
  • Gazebo
  • Nvidia Issac Sim
  • MQTT
  • Simulink
  • Fusion 360
  • Blender
  • OpenWRT
  • Arduino

Latest works

Batch Informed Trees

Generally, we can divide the approximations used in path planning into 2 types: Search-based and Sampling-based.

A recent approach called Batch Informed Trees (BIT*) combines the strengths of both search-based and sampling-based planners. In this work, we have used the pseudo-code from the paper and coded the algorithm from scratch, and tested its performance in R2 space for different motion planning scenarios using a custom visualizer.

Details

Learning Inverse Kinematics using Reinforcement Learning

In this project, we present a Reinforcement Learning (RL) approach to the problem of Inverse Kinematics (IK), which involves controlling the end-effector of a 7 Degrees-of- Freedom (DoF) robotic arm to enable it to reach a target posi- tion. Our approach uses a policy gradient approach with non- linear function approximators like neural networks. Three major algorithms were investigated in this research (DDPG, SAC and TD3 algorithms). In addition, we see the effect of different reward structures in learning the optimal policy for our chosen domain. We demonstrate the effectiveness of our approach through experiments on a simulated robotic arm, showing that our method is able to learn a policy that can successfully control the arm to reach the target position.

Report Code

Intelligent Quads - Open Source Guidance, Navigation and Control Project

Intelligent Quads is a community dedicated to helping people learn how to become developers of intelligent drone applications.

The intelligent quads gnc_functions are collection of high level functions to help make controlling your drone simple. You can find functions for interpreting state estimation, commanding waypoints, changing modes and more. The documentation for using these functions is shown here.

Code

Vargi Bots - e-Yantra (Finalist)

Inspired by Industry 4.0 principles, the e-Yantra Robotics Competition's latest edition showcases 'Vargi-Bots.' This theme centers on an automated warehouse management system within the Gazebo simulator, using ROS as a middleware. The setup includes two industrial robotic arms responsible for sorting and dispatching essential packages to various city locations. Notably, high-priority packages, such as those needed for emergencies, are given priority. Participants are challenged to design a smart controller to optimize the delivery process. The updates are sent out using MQTT in Python and are trackable in Google Sheets, which is automated through the Google Sheets API controlled using Python.

Code