Welcome to the website of the Geometric and Physical Computing group at Northeastern University’s College of Computer and Information Science. We develop algorithms, software, and hardware to address open problems in robotics, perception, manufacturing, and human-machine interfaces.

We collaborate closely with Rob Platt’s group.

PI: Marsette Vona (on leave during the 2014-15 academic year)

Current Projects

Mouseover each image for a description, click for details.

Past Projects

News

July 24, 2014:
Our Ph.D. student Dimitrios Kanoulas successfully defended his dissertation Curved Surface Patches for Rough Terrain Perception. Congratulations Dimitrios! Thank you to our committee members Rob Platt, Guevara Noubir, and Seungkook Yun (external member, SRI International). This thesis introduces a new method to identify and model potential contact areas between a robot and an environment surface using a set of bounded curved patches. A patch parameterization model, fitting and validation algorithms, and a dynamic spatial patch map are all presented. The map represents a sparse set of local areas potentially appropriate for contact between the robot and the environment. These algorithms are integrated with a dense volumetric fusion of range data from a moving depth camera, and were experimentally tested as part of a real-time foothold perception system on a mini-biped robot that performs foot placements on rocks.

Starting in Sept 2014 Dimitrios will be a postdoctoral researcher with Nikos Tsagarakis at the Department of Advanced Robotics at the Istituto Italiano di Tecnologia (IIT).

May 29, 2014: Our student Sergio Castro Gomez presented his M.S. thesis Sensing with a 3-Toe Foot for a Mini-Biped Robot. This work introduces a novel foot design incorporating 3 flexural toes. Hall-effect sensors detect toe deflections and enable estimation of the forces and torques acting on the foot. We implemented the design and Sergio performed extensive experiments comparing the results to both ground truth (from a commercial load cell temporarily installed in the ankle) and a commercial foot with force sensing resistors.

April 15, 2014: Our student Benjamin Arneberg presented his M.S. thesis Design and Evaluation of an Indoor Navigation and Mapping System for Autonomous Vehicles. This thesis makes several improvements on existing navigation algorithms and runs the most promising configuration in real-time onboard a custom quadrotor system for a full flight demo.

April 1, 2014: We have been selected to give a presentation on our Surface Patch Library (SPL) at the ICRA 2014 MATLAB/Simulink for Robotics Education and Research workshop, Thursday June 5, 2014 at ICRA in Hong Kong, China. The Surface Patch Library (SPL) is an open-source Matlab toolbox for prototyping 3D rough terrain perception algorithms. It includes models of 10 types of curved surface patches, an algorithm to fit patches to potentially noisy range sensor data, and an algorithm to perceptually validate patches. Uncertainty is quantified throughout using covariance matrices. The patches are designed to model local contact regions both in the environment (e.g. on rocky surfaces) and on a robot (e.g. foot pads). Our Ph.D. student Dimitrios Kanoulas will give the talk.

January 31, 2014: Our imucam system is now available under BSD license. imucam is a library and a set of utilities built on PCL to work with a CHR UM6 IMU mounted on an OpenNI 1.x compatible depth camera like the Microsoft Kinect. Code is included to grab, save, and playback full-frame 30FPS depth data and corresponding 100Hz IMU data. A calibration tool is provided to estimate the rigid rotation of the IMU relative to the camera based on captured depth images of a flat horizontal ground plane.

January 31, 2014: Our rxkinfu system is now available under BSD license. rxkinfu is library and application for Moving Volume Kinect Fusion. KinectFusion is an algorithm for real-time dense 3D mapping using a depth camera like the Kinect. The original system is limited to a relatively small volume fixed in the world at start up (typically a ~3m cube). This limits applications for perception and robotics. Moving Volume KinectFusion adds volume remapping features to allow the camera to roam freely.

January 14, 2014: Our paper Bio-Inspired Rough Terrain Contact Patch Perception was accepted for publication at ICRA 2014. In this paper we present a new bio-inspired system for automatically finding foot-scale curved surface patches in rough rocky terrain. Input is from a depth camera augmented with a 9-DoF inertial measurement unit to sense the direction of gravity. The algorithm is capable of finding approximately 700 patches/second on commodity hardware. Sixty recordings of human subjects traversing rocky trails were analyzed to give a bio-inspired baseline for target patch properties. The output patches for possible footholds are statistically similar to the patches humans select.

This builds on our ICRA 2013 paper Sparse Surface Modeling with Curved Patches and our IROS 2011 paper Curved Surface Contact Patches with Quantified Uncertainty.

October 7, 2013: Our Ph.D. student Dimitrios Kanoulas presented a poster at the Northeast Robotics Colloquium entitled “Surface Patches for Rough Terrain Perception”. Also pictured are Andreas ten Pas and Di Sun from Rob Platt’s group and their poster “Encoding Grasp Affordances in 3-D Point Clouds Using Taubin Quadric Fitting”.

January 7, 2013: Our paper Sparse Surface Modeling with Curved Patches was accepted for publication at ICRA 2013. This builds on our IROS 2011 paper Curved Surface Contact Patches with Quantified Uncertainty.

August 21, 2012: Our paper Teaching Robotics Software with the Open Hardware Mobile Manipulator was accepted for publication in the IEEE Transactions on Education special issue on Robotics Education. This paper presents our new open-hardware/open-source OHMM platform for teaching robotics software and algorithms, along with pedagogical results from using it in our course CS4610.

August 21, 2012: Controlling a Robot from Another Planet, an interview with Prof. Vona about the NASA Curiosity rover, was featured on the NEU website today.

July 26, 2012: Ph.D. student Dimitrios Kanoulas gave talks on our patch-based perception algorithms to the e-Motion and PERCEPTION teams at INRIA and at LAAS-CNRS Toulouse.

July 6, 2012: Our new paper Moving Volume KinectFusion has been accepted at the British Machine Vision Conference (BMVC) 2012. Newcombe and Izadi et al’s KinectFusion is an impressive new system for real-time tracking and dense 3D mapping using the Kinect. The original algorithm is limited to a relatively small volume fixed in the world, limiting applications for mobile robot perception. Our approach adds remapping algorithms that allow the camera to roam freely. Shortly after we submitted our work for peer review in May 2012 we learned that two other groups are also developing alternative approaches to scale up the KinectFusion map. A key distinction of our method is the ability to rotate the volume. We have implemented our system based on the kinfu implementation in the Point Cloud Library, and we are preparing our code for an open-source release. Videos and more info here.

May 14, 2012: The Driverless Car, an interview with Prof. Vona about the robotic technology behind driverless cars, was featured on the NEU website today.

May 1, 2012: Ph.D. students Henry Roth and Dimitrios Kanoulas will travel this summer for research internships at NASA/JPL in Pasadena, CA and INRIA in Grenoble, France. Henry will be working with Jeff Norris’s OPS Lab on a new augmented reality system using KinectFusion; Dimitrios will be working with the e-Motion group on perception algorithms for road and traffic environments.

April 27, 2012: M.S. student Jessica Lowell presented her thesis BlueSANE: Integrating Functional Blueprints with Neuroevolution today. Prof. Vona was her advisor and Joe Ayers was also on the committee. Jessica will enter the Ph.D. program at Tufts University in the fall.

February 28, 2012: Building a Better Robot, a story about our research and Prof. Vona’s recently awarded NSF CAREER grant on 3D perception and compliant contact, was featured on the NEU website today.

January 29, 2012: The new website for OHMM is now live with details on the robot, photos, hardware designs, software sources, and curriculum materials.

Older News

Research

We are currently focusing on several problems in perception and control for bipedal and humanoid locomotion on very uneven 3D terrain. These were motivated by some of our prior work in compliant climbing and stair-stepping, which led us to consider how compliant and proprioceptive motion strategies can be combined with on-line perception of uncertain contact surfaces.

3D Perception in Unstructured Environments

We are developing a set of curved and flat patch models to represent both nearby environment surfaces and contacting surfaces on a robot including foot soles and fingertips. Unlike prior approaches (e.g. algebraic surfaces) we use geometrically meaningful minimal parameterizations, we quantify uncertainty in patch shape and pose, and we include the patch boundary. Fast perceptual algorithms can detect instances of these patches around a moving robot, and as patches are observed and re-observed a spatial map can be built to support motion planning and control.

We recently released a new software package called the Surface Patch Library (SPL) which includes models of 10 types of curved surface patches and an algorithm to fit them to potentially noisy range sensor data. Uncertainty is quantified throughout using covariance matrices. Some of the mathematical foundations of the system are described in this paper.

We are also working with KinectFusion to develop algorithms that will enable its use on a mobile robot in rough terrain. This could provide both localization and a low-level dense model of nearby terrain upon which we can fit higher-level surface patches. In our first paper in this area we present experiments with a remapping approach to allow the KinectFusion modeling volume to move with the sensor through the world. More info and videos here.

Measuring Human Locomotion and Perception in Unstructured Environments

A primary advantage of bipedal locomotion (vs wheels or tracks) is the potential to negotiate highly faceted 3D trails as humans do. An understanding of how to address this challenge will help enable intelligent prosthetics, human locomotion aids, and robots that can safely follow and assist humans in rugged terrain.

Sensing and mapping upcoming footholds in real time seems inescapable for this task. Though some recent robots have achieved impressive advances in mechanics and control for walking on rough terrain, they largely operate without significant forward-looking perception. Work to implement these perceptual functions, or even to study human perception in this task, is still in its infancy. We are thus developing a body-worn sensor system to acquire quantitative datasets observing human locomotion on rocks and correlated perceptual behavior.

Bipedal Locomotion on Uneven Terrain

We are studying humanoid locomotion on terrain composed of sloped planar facets as an in-lab approximation for hiking on a rocky trail. We are considering a four-phase strategy: (1) acquisition of a next-facet pose estimate by range sensors, including a quantified estimate of uncertainty; (2) passive compliant foot placement based on this estimate, with leg stiffness modulated according to the degree of uncertainty; (3) post-contact proprioception (joint angle sensing) to reduce uncertainty; (4) follow-through of torso and trailing leg with up-modulated leg stiffness for control.

Though most existing humanoids have high-impedance joint actuators, recently a few low-cost mini-humanoids have become available which enable modulation of actuator stiffness by a combination of passive backdriveability and on-line adjustment of servo position loop proportional gain. Our experimental apparatus is based on this approach to control joint compliance.

People

Marsette Vona
Assistant Professor

Completed

Dimitrios Kanoulas, Ph.D. Student, 2014: Curved Surface Patches for Rough Terrain Perception.
Now a postdoc at the Department of Advanced Robotics at the Istituto Italiano di Tecnologia (IIT).
Sergio Castro Gomez, M.S. Student, ECE, 2014: Sensing with a 3-Toe Foot for a Mini-Biped Robot.
Benjamin Arneberg, M.S. Student, 2014: Design and Evaluation of an Indoor Navigation and Mapping System for Autonomous Vehicles.
Henry Roth, M.S. Student, 2013: Moving Volume Kinect Fusion.
Jessica Lowell, M.S. Student, 2012: BlueSANE: Integrating Functional Blueprints with Neuroevolution.
Now in the Ph.D. program at Brandeis University.

Rob Platt’s Group

The GPC group collaborates closely with Rob Platt’s group.

Robert Platt, Jr.
Assitant Professor
Di Sun
Ph.D. Student
Andreas Ten Pas
Ph.D. Student
Prahasaran Raja
M.S. Student (SUNY Buffalo)
Nate Roscup
M.S. Student
Mordechai Rynderman
M.S. Student

Funding

Past and present research funding:

Directions

The best way to contact us is to send email to Marsette Vona.

If you will be visiting us, our lab is located in 214 West Village H, 440 Huntington Avenue, Boston MA (map). Take the MBTA Green Line E train to the Northeastern stop, then walk one block west on Huntington Ave. WVH is the glass-facade building at the corner of Parker and Huntington, diagonally southeast across Huntington from the Museum of Fine Arts.

Our mailing address is

360 Huntington Ave
202 WVH, attn Marsette Vona
Boston, MA 02115

Links

Some of our colleagues and collaborators include