Nikolaus Correll

Nikolaus Correll
University of Colorado Boulder | CUB · Department of Computer Science (CS)

PhD CS

About

163
Publications
51,051
Reads
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4,903
Citations
Additional affiliations
August 2009 - present
University of Colorado Boulder
Position
  • Professor (Assistant)
October 2007 - August 2009
Massachusetts Institute of Technology
Position
  • PostDoc Position

Publications

Publications (163)
Article
Full-text available
Developing robot agnostic software frameworks involves synthesizing the disparate fields of robotic theory and software engineering while simultaneously accounting for a large variability in hardware designs and control paradigms. As the capabilities of robotic software frameworks increase, the setup difficulty and learning curve for new users also...
Article
Full-text available
C-FOREST is a parallelization framework for single-query sampling-based shortest path-planning algorithms. Multiple search trees are grown in parallel (e.g., 1 per CPU). Each time a better path is found, it is exchanged between trees so that all trees can benefit from its data. Specifically, the path's nodes increase the other trees' configuration...
Article
Full-text available
This paper describes a one-year introductory robotics course sequence focusing on computational aspects of robotics for third- and fourth-year students. The key challenges this curriculum addresses are scalability, i.e., how to teach a robotics class with a limited amount of hardware to a large audience,student assessment, i.e., how to assess the s...
Article
Full-text available
We propose a combined spatial and non-spatial probabilistic modeling methodology motivated by an inspection task performed by a group of miniature robots. Our models explicitly consider spatiality and yield accurate predictions on system performance. An agent’s spatial distribution over time is modeled by the Fokker—Planck diffusion model and compl...
Article
Full-text available
The impressive agility of living systems seems to stem from modular sensing, actuation and communication capabilities, as well as intelligence embed-ded in the mechanics in the form of active compliance. As a step towards bridging the gap between man-made machines and their biological counterparts, we devel-oped a class of soft mechanisms that can...
Preprint
Full-text available
We present a suite of algorithms and tools for model-predictive control of sensor/actuator systems with embedded microcontroller units (MCU). These MCUs can be colocated with sensors and actuators, thereby enabling a new class of smart composites capable of autonomous behavior that does not require an external computer. In this approach, kinematics...
Article
We present a novel augmented reality (AR) framework to show relevant information about swarm dynamics to a user in the absence of markers by using blinking frequency to distinguish between groups in the swarm. In order to distinguish between groups, clusters of the same group are identified by blinking at a specific time interval that is distinct f...
Article
The need to create more viable soft sensors is increasing in tandem with the growing interest in soft robots. Several sensing methods, like capacitive stretch sensing and intrinsic capacitive self-sensing, have proven to be useful when controlling soft electro-hydraulic actuators, but are still problematic. This is due to challenges around high-vol...
Chapter
We present a high-bandwidth, lightweight, and nonlinear output tracking technique for soft actuators that combines parsimonious recursive layers for forward output predictions and online optimization using Newton-Raphson. This technique allows for reduced model sizes and increased control loop frequencies when compared with conventional RNN models....
Article
The Mobile Manipulation Hackathon was held in late 2018 during the IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) to showcase the latest applications of wheeled robotic manipulators. The challenge had an open format, where teams developed an application using simulation tools and integrated it into a robotic platform. Th...
Preprint
Full-text available
We present a high-bandwidth, lightweight, and nonlinear output tracking technique for soft actuators that combines parsimonious recursive layers for forward output predictions and online optimization using Newton-Raphson. This technique allows for reduced model sizes and increased control loop frequencies when compared with conventional RNN models....
Article
Soft robotics is a field of robotic system design characterized by materials and structures that exhibit large-scale deformation, high compliance, and rich multifunctionality. The incorporation of soft and deformable structures endows soft robotic systems with the compliance and resiliency that makes them well adapted for unstructured and dynamic e...
Preprint
Soft robotics is a field of robotic system design characterized by materials and structures that exhibit large-scale deformation, high compliance, and rich multifunctionality. The incorporation of soft and deformable structures endows soft robotic systems with the compliance and resiliency that makes them well-adapted for unstructured and dynamic e...
Article
A comprehensive Bioregenerative Life Support System (BLiSS) for human Long-duration Space Exploration Missions (LDEMs) requires an innovative design philosophy and novel technical solutions. SIRONA: Sustainable Integration of Regenerative Outer-space Nature and Agriculture is a greenhouse design that produces a wide variety of food sources and prov...
Article
Soft robots are becoming increasingly prevalent, with unique applications to medical devices and wearable technology. Understanding the dynamics of nonlinear soft actuators is crucial to creating controllable soft robots. This paper presents a system identification process and closed-loop control of foldable HASEL (hydraulically amplified self-heal...
Preprint
Full-text available
We present algorithms and results for a robotic manipulation system that was designed to be easily programmable and adaptable to various tasks common to industrial setting, which is inspired by the Industrial Assembly Challenge at the 2018 World Robotics Summit in Tokyo. This challenge included assembly of standard, commercially available industria...
Article
Full-text available
We present algorithms and results for a robotic manipulation system that was designed to be easily programable and adaptable to various tasks common to industrial setting, which is inspired by the Industrial Assembly Challenge at the 2018 World Robotics Summit in Tokyo. This challenge included assembly of standard, commercially available industrial...
Chapter
Full-text available
We posit that embodied artificial intelligence is not only a computational, but also a materials problem. While the importance of material and structural properties in the control loop are well understood, materials can take an active role during control by tight integration of sensors, actuators, computation and communication. We envision such mat...
Article
Full-text available
The Industrial Assembly Challenge at the World Robot Summit was held in 2018 to showcase the state-of-the-art of autonomous manufacturing systems. The challenge included various tasks, such as bin picking, kitting, and assembly of standard industrial parts into 2D and 3D assemblies. Some of the tasks were only revealed at the competition itself, re...
Preprint
We present a method to register individual members of a robotic swarm in an augmented reality display while showing relevant information about swarm dynamics to the user that would be otherwise hidden. Individual swarm members and clusters of the same group are identified by their color, and by blinking at a specific time interval that is distinct...
Preprint
Full-text available
The Industrial Assembly Challenge at the World Robot Summit was held in 2018 to showcase the state-of-the-art of autonomous manufacturing systems. The challenge included various tasks, such as bin picking, kitting, and assembly of standard industrial parts into 2D and 3D assemblies. Some of the tasks were only revealed at the competition itself, re...
Preprint
Full-text available
We present a library to automatically embed signal processing and neural network predictions into the material robots are made of. Deep and shallow neural network models are first trained offline using state-of-the-art machine learning tools and then transferred onto general purpose microcontrollers that are co-located with a robot's sensors and ac...
Article
This paper examines the important problem of cooperative localization in robot swarms, in the presence of unmodeled errors experienced by real sensors in hardware platforms. Many existing methods for cooperative swarm localization rely on approximate distance metric heuristics based on properties of the communication graph. We present a new coopera...
Presentation
Full-text available
We present novel tools to perform neural network predictions in a composite material with embedded sensors, actuators and computers. We also demonstrate the possibility of making estimations in complex systems where sensor locations are unknown or where dynamic modeling for system identification may be very complex.
Preprint
Full-text available
The Computing Community Consortium (CCC) sponsored a workshop on "Robotic Materials" in Washington, DC, that was held from April 23-24, 2018. This workshop was the second in a series of interdisciplinary workshops aimed at transforming our notion of materials to become "robotic", that is have the ability to sense and impact their environment. Resul...
Article
Full-text available
The lack of sensory feedback provided by prosthetic hands dramatically limits the utility of the device. Peripheral nerve interfaces are now able to produce stable somatosensory percepts for upper-limb amputees. Sensors must be able to detect forces across the fingers of the prosthesis in a repeatable and reliable fashion. We solved this concern wi...
Book
This volume of the SPAR series brings the proceedings of the fourteen edition of the DARS symposium on Distributed Autonomous Robotic Systems, whose proceedings have been published within SPAR since the past edition. This symposium took place in Boulder, CO from October 15th to 17th, 2018. The volume edited by Nikolaus Correll and Mac Schwager cont...
Article
Full-text available
We present a distributed algorithm for a swarm of active particles to camouflage in an environment. Each particle is equipped with sensing, computation and communication, allowing the system to take color and gradient information from the environment and self-organize into an appropriate pattern. Current artificial camouflage systems are either lim...
Article
Full-text available
We solve the multi-robot path planning problem using three complimentary techniques: (1) robots that must coordinate to avoid collisions form temporary dynamic teams. (2) Robots in each dynamic team become a distributed computer by pooling their computational resources over ad hoc wireless Ethernet. (3) The computational complexity of each team’s p...
Article
We describe a robotic material that tightly integrates sensing, actuation, computation, and communication to perform autonomous shape change. The composite consists of multiple cells, each with the ability to control their local stiffness (by Joule heating of a thermoplastic) and communicate with their local neighbors. We also present a distributed...
Article
Full-text available
We describe a combined proximity, contact and force (PCF) sensor based on a commodity infrared distance sensor embedded in a transparent elastomer with applications in robotic manipulation. Prior to contact, the sensor works as a distance sensor, whereas after contact the elastomer magnifies the near field of the proximity sensors letting the senso...
Preprint
Full-text available
We identify the components of bio-inspired artificial camouflage systems including actuation, sensing, and distributed computation. After summarizing recent results in understanding the physiology and system-level performance of a variety of biological systems, we describe computational algorithms that can generate similar patterns and have the pot...
Chapter
Full-text available
We describe our approach to the IROS “Hand-in-Hand” manipulation challenge using a simple one degree-of-freedom prehensor, which is known to be highly effective in prosthetic applications. The claw consists of two prongs of which only one is mobile, requiring the user to first make contact with the immobile prong to create a constraint and then use...
Chapter
We describe the grasping and manipulation strategy that we employed at the autonomous track of the Robotic Grasping and Manipulation Competition at IROS 2016. A salient feature of our architecture is the tight coupling between visual (Asus Xtion) and tactile perception (Robotic Materials), to reduce the uncertainty in sensing and actuation. We demo...
Conference Paper
Full-text available
We describe a self-sensing composite capable of making online estimations on the location of an impact within its structure without the need for wires or offline data processing. We embed a network of piezoelectric sensors in the material during manufacturing and connect each sensor to a dedicated micro-controller and power source. Triangulation is...
Chapter
We present a distributed algorithm for a swarm of active particles to camouflage in an environment. Each particle is equipped with sensing, computation, and communication, allowing the system to take color and gradient information from the environment and self-organize into an appropriate pattern. Current artificial camouflage systems are either li...
Chapter
We investigate distributing convolutional neural networks (CNNs) for human activity recognition across computing nodes collocated with sensors at specific regions (body, arms and legs) on the wearer. We compare four CNN architectures. A distributed CNN is implemented on a network of Intel Edison nodes, demonstrating the capability of performing rea...
Article
We describe a flexible robotic skin module that can measure proximity, contact and force, as well as algorithms for detecting obstacles, human hands, and affective touch gestures. The computational requirements of the proposed architecture are in line with the capabilities of a small microcontroller, allowing for a majority of the data to be proces...
Chapter
Full-text available
We propose linearizing about zero-control trajectories of the dynamics and cost instead of linearizing about a single point for steering and distance computations in RRT-like motion planning for highly dynamic systems. Formulated as a time-varying Linear Quadratic Regulator problem, the proposed steering is designed to be efficient and numerically...
Article
Full-text available
We describe a self-sensing composite capable of making online estimations on the location of an impact within its structure without the need for wires or offline data processing. We embed a network of piezoelectric sensors in the material during manufacturing and connect each sensor to a dedicated micro-controller and power source. Triangulation is...
Article
Biology motivates how complex functionality results from systems of simple materials.
Conference Paper
We describe opportunities and challenges with wireless robotic materials. Robotic materials are multi-functional composites that tightly integrate sensing, actuation, computation and communication to create smart composites that can sense their environment and change their physical properties in an arbitrary programmable manner. Computation and com...
Article
We posit that embodied artificial intelligence is not only a computational, but also a materials problem. While the importance of material and structural properties in the control loop are well understood, materials can take an active role during control by tight integration of sensors, actuators, computation and communication. We envision such mat...
Article
Full-text available
We describe opportunities and challenges with wireless robotic materials. Robotic materials are multi-functional composites that tightly integrate sensing, actuation, computation and communication to create smart composites that can sense their environment and change their physical properties in an arbitrary programmable manner. Computation and com...
Article
The emerging field of soft robotics makes use of many classes of materials including metals, low glass transition temperature (Tg) plastics, and high Tg elastomers. Dependent on the specific design, all of these materials may result in extrinsically soft robots. Organic elastomers, however, have elastic moduli ranging from tens of megapascals down...
Conference Paper
Full-text available
The field of upper limb prosthetic design seeks to recreate what was lost after amputation including the loss of sensation. In order to accomplish this feat, prosthetic devices require compact, stable, and clinically robust sensors in order to measure interaction with the external environment. These types of sensors are more important now since dra...
Conference Paper
Full-text available
We demonstrate how low-cost in-hand proximity and dynamic tactile sensing can dramatically improve the reliability of basic manipulation tasks. We use an array of infrared proximity sensors embedded in a transparent elastic polymer and an accelerometer in the robot’s wrist to extract proximity and dynamic tactile information that is inspired by the...
Article
Full-text available
We present an radio-frequency (RF)-based approach to gesture detection and recognition, using e-textile versions of common transmission lines used in microwave circuits. This approach allows for easy fabrication of input swatches that can detect a continuum of finger positions and similarly basic gestures, using a single measurement line. We demons...
Article
Full-text available
We describe the grasping and manipulation strategy that we employed at the autonomous track of the Robotic Grasping and Manipulation Competition at IROS 2016. A salient feature of our architecture is the tight coupling between visual (Asus Xtion) and tactile perception (Robotic Materials), to reduce the uncertainty in sensing and actuation. We demo...
Article
Full-text available
We present a distributed algorithm to calculate inverse kinematic solutions for shape-changing beams with integrated sensing, actuation, computation and communication. We consider the beam to consist of n segments that can each change their curvature, perform computation and communicate with their neighbors. Using a centralized inverse Jacobian met...
Chapter
This paper provides preliminary insight into stiffness profile identification of a complex flexible object by robotic manipulation. The object is in the shape of the letter ‘Y’, chosen to resemble a living plant. The object is approximately modeled as a spring mass system. The robot manipulates the object with one or two arms grasped at the ends of...
Article
Full-text available
We present methods for offline generation of sparse roadmap spanners that result in graphs 79% smaller than existing approaches while returning solutions of equivalent path quality. Our method uses a hybrid approach to sampling that combines traditional graph discretization with random sampling. We present techniques that optimize the graph for the...
Article
This paper presents an overview of the inaugural Amazon Picking Challenge along with a summary of a survey conducted among the 26 participating teams. The challenge goal was to design an autonomous robot to pick items from a warehouse shelf. This task is currently performed by human workers, and there is hope that robots can someday help increase e...
Article
Full-text available
Coordinated collective behaviors often emerge from simple rules governing the interactions of individuals in groups. We model mechanisms of coordination among ants during cooperative transport, a challenging task that requires a consensus on travel direction. Our goal is to determine whether groups following simple behavioral rules can reach a cons...
Data
Persistence and sensitivity effects in informed case at different group sizes. Effect of persistence (inverse of maximum giving-up rate constant) on maximum coordination in small, moderate, and large informed groups at low (gradual) shape values. Maximum giving-up rate constant is the maximum possible as defined by the function, actual values will...
Data
Analysis of deadlock stability in informed case. (DOCX)
Data
Persistence effects at different group sizes. Effect of persistence (inverse of maximum giving-up rate constant) on maximum coordination for small, moderate, and large groups. Maximum giving-up rate constant is the maximum possible as defined by the function, actual values will depend on the number of individuals in each group. Extent of coordinati...
Data
Coding supplement (zip file). All code is included here. S1 Code also includes example parameter sets necessary to reproduce Figs 3 through 7. (ZIP)
Data
Simulation results. Movie of histograms showing the state of 1,000 simulations of the stochastic model for each of nine parameter sets. Each frame is a time point. Each panel is a set of parameter values, corresponding to the analogous panels in Figs 3 and 4. Blue bars show the number of simulations for which the number of ants moving right had tha...
Conference Paper
We wish to simulate basic rules of chemistry using a swarm of miniature robots, which mimic atoms and forming molecules. Atomic scale interactions are difficult to observe and computer simulations or ball-and-stick models capture either behavioral or embodied aspects, but not both. Miniature robots that are able to determine their orientation and p...
Preprint
Coordinated collective behaviors often emerge from simple rules governing the interactions of individuals in groups. We model mechanisms of coordination among ants during cooperative transport, a challenging task that requires a consensus on travel direction. Decisions required for cooperative transport differ from other, well-studied consensus dec...