Thrust Overview

Introduction

The Olin Robotics Lab is broken up into separate thrusts working on different aspects of robotic development from underwater and eusocial robotics to heavy machinery and drones. In order to facilitate cross-thrust resource accessibility, this page lists the main developments and strengths of each thrust.

TEMPLATE: Example Thrust Documentation

Languages	Packages	Computational Platforms	Electronics	Projects
Python	OpenCV	Arduino	Sabertooth	Robot Sloth Research
C++		Raspberry Pi	72MHz Radio	Arduino to Raspberry Pi Comms

Robot Sloth Research

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Arduino to Raspberry Pi Comms

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GRAVL: Ground Robotic Autonomous Vehicle Lab

Languages	Packages	Computational Platforms	Electronics	Projects
Python	OpenCV	Arduino Teensy	Roboclaw Motor Controller	LiDAR 2D & 3D Feature Detection
C++		Intel NUC	72MHz Radio	Rosserial on Arduino Teensy
			Logitech Controller	Game Controller ROS interface
				Road Detection

Baymax: Eusocial Robotics

Languages	Packages	Computational Platforms	Electronics	Projects
Python	OpenCV	Arduino Mega	Arduino Motorshield	Peekaboo with Face Detection
C++	nltk		Hi-Tech Servos	Gesture Mimicking Using Kinect
				Emotional Model for Robots Using nltk
				Fluid Reinforced Soft Robotics

ORCAS: Olin Robotics Collaborative Autonomous Submersibles

Languages	Packages	Computational Platforms	Electronics	Projects
Python	OpenCV	Arduino	Afro ESC	The Olin Cross Tunnel Thruster
C++		Odroid Xu4	Marine ESC	Structured Light Imaging System
				Variable Ballast UUV

The Olin Cross Tunnel Thruster

A third focus involved conducting research and testing the design and application of cross-tunnel thrusters. This form of thruster reduces drag by internally packaging the motor and tunnel system. It is used for low-speed precision navigation in submarine systems, especially for resisting surface-level wave thrust or docking maneuvers. We replicated the cross-tunnel design in CAD so that variations on tunnel length, wall thickness, and overall design could be rapidly prototyped. This included maximizing tunnel inner diameter while retaining material stability, testing fit tolerances for hardware-free attachment, experimenting with detachable tunnel connections, and creating a mounting stand that would match the geometry of the Skipjack hull. Additionally, we prototyped a solution for sealing existing motors with electrical tape and epoxy so that we could submerge the thrusters and determine flow rate. We are planning to continue this work with larger, water-proof thrusters, and scale these initial designs to integrate cross-tunnel thrusters into other submarine platforms.

Structured Light Imaging System

A high priority this semester was the development of a structured light laser imaging sensor system. Developing a highly maneuverable UUV for navigating littoral (shallow, coastal) waters requires the ability to avoid obstacles (i.e. underwater pylons, submerged bridge columns, etc.) while navigating. As such, a large amount of research and development effort went into creating a successful vehicle-mounted structured light laser imaging system.

Variable Ballast UUV

We spent a good amount of time this semester developing the supportive mechanical systems for an intermediate testing rig called the Skipjack. Originally a 40 inch model submarine, this vehicle will serve as the first testing platform for the Olin Cross Tunnel Thruster system. Because the submarine was originally a model, there was no pre-existing CAD to describe its geometry. As such, a lot of effort was put into accurately modeling the complex 3D geometry of the submarine’s hull. The CAD model was essential for further designing other mechanical components of the sub, such as the dedicated laser/camera pressure hull at the fore of the vehicle, as well as the placements/mounting points for the cross tunnel thrusters. This work in modeling the future testing platform for this project will expedite the development process in the coming semester as the structured light navigation gets integrated directly into the main vehicle. In addition to using the CAD as a tool for designing mounts that can interface with the sub’s fiberglass hull, we will be able to use the CAD model to determine important and complex features of the submarine, such as the center of buoyancy and center of mass, as to make more informed and nuanced engineering decisions.

MORA: Miniature Oscillatory Robot Agent (Robofish swarms!)

Languages	Packages	Computational Platforms	Electronics	Projects
C++		Arduino	L298 H-Bridge	Untethering MORA
MATLAB			MIC Actuator	Autonomous MORA
				MIC Actuator Feedback Control

Untethering MORA

We have a 12cm long, tethered robot fish. Our next step is to move all of the electronics inside, removing the tether which impedes the fish's motion, and taking the next step towards having a swarm of MORAs. How do we put batteries inside of a tiny fish, waterproof them, and make the easily chargeable/replaceable? How do we downsize our electronics board and waterproof it, perhaps getting into some soft robotics techniques? We will be playing with soft silicone skins, miniaturizing electronics, and waterproofing. In the process, the physical fish body may need to get modified as well.

Autonomous MORA

MORA can currently swim forwards at a slow speed. How do we increase the speed and efficiency of the forward swimming gait? Perhaps we build a model and find the optimal set of parameters for the movement of the robot, maybe using some ML. How do we use the three independently actuated joints to turn the robot? Can we add a remote controlled feature to the robot? This project involves exploring the control of our three actuators to achieve better forward and turning swimming gaits, and adding wireless communication for debugging and direct control of the robot.

MIC Actuator Feedback Control

Our MIC actuator can move back and forth, and controlling the PWM signal and turning off the current for some time can force the MIC to move in a sinusoidal motion. However, we only know if the actuator is either right or left. Can we get positional feedback for our actuators to create a more accurate control loop? We will be playing around with Hall effect sensors to measure the direction of electric fields. Additionally, there is potential to find other tiny, inexpensive actuators, like RC plane motors which use the same MIC principle, but are already configured for proportional control.

Last edited by ksoltan: 9/2/2018