Author name cluster

Nicholas Farrow

Possible papers associated with this exact author name in Arrow. This page groups case-insensitive exact name matches and is not a full identity disambiguation profile.

5 papers

2 author rows

ICRA Conference 2017 Conference Paper

Functionalized textiles for interactive soft robotics

Nicholas Farrow
Lauren McIntire
Nikolaus Correll

We use a conductive fabric substrate as a building material for a soft sensor to extend the functionality of soft actuators. We use PCB etching techniques to apply a pattern to the fabric, yielding distinct conductive surfaces within the same textile. We connect these via flexible wire bus embedded in silicone, terminating in a flexible PCB. We show how touch and metal objects can be localized along the length of the composite fabric strip. We demonstrate an example soft robotic application, by replacing the constraint layer component in a PneuFlex-style soft actuator with the self contained sensing strip. We show that the augmented composite actuator is able to interact with conductive objects in the environment using a capacitive touch sensing with applications in grasping and human-robot interaction.

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IROS Conference 2015 Conference Paper

A soft pneumatic actuator that can sense grasp and touch

Nicholas Farrow
Nikolaus Correll

We present a fiber reinforced soft pneumatic actuator with integrated strain and pressure sensors. We demonstrate that combining these sensors into the same actuator enables proprioception of both actuator curvature and environmental contact forces. We describe the manufacture and integration of a simple liquid metal strain sensor, a pressure sensor, and electrical circuits used for the sensors. We derive a constant curvature model for the actuator which predicts actuator curvature from the air pressure, and other constants of manufacture. The utility of the sensor integration is demonstrated by using the actuator to distinguish successful grasps amongst a set of common cylindrical objects with varying diameter. The grasp radius is estimated from the relationship between the sensor pair. Contact forces with the environment (touch) may be inferred from sensor readings which deviate from unconstrained motion.

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TAAS Journal 2015 Journal Article

Distributed Spatiotemporal Gesture Recognition in Sensor Arrays

Homa Hosseinmardi
Akshay Mysore
Nicholas Farrow
Nikolaus Correll
Richard Han

We present algorithms for gesture recognition using in-network processing in distributed sensor arrays embedded within systems such as tactile input devices, sensing skins for robotic applications, and smart walls. We describe three distributed gesture-recognition algorithms that are designed to function on sensor arrays with minimal computational power, limited memory, limited bandwidth, and possibly unreliable communication. These constraints cause storage of gesture templates within the system and distributed consensus algorithms for recognizing gestures to be difficult. Building up on a chain vector encoding algorithm commonly used for gesture recognition on a central computer, we approach this problem by dividing the gesture dataset between nodes such that each node has access to the complete dataset via its neighbors. Nodes share gesture information among each other, then each node tries to identify the gesture. In order to distribute the computational load among all nodes, we also investigate an alternative algorithm, in which each node that detects a motion will apply a recognition algorithm to part of the input gesture, then share its data with all other motion nodes. Next, we show that a hybrid algorithm that distributes both computation and template storage can address trade-offs between memory and computational efficiency.

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IROS Conference 2014 Conference Paper

A stick-slip omnidirectional powertrain for low-cost swarm robotics: Mechanism, calibration, and control

John Klingner
Anshul Kanakia
Nicholas Farrow
Dustin Reishus
Nikolaus Correll

We present an omnidirectional powertrain for swarm robotic platforms that relies on low-cost vibration motors. We describe a mechanism and controller to achieve full 3-DoF motion on the plane. The proposed approach does not require the motors to be in phase, and overcomes differences in manufacturing by a hardware-in-the-loop auto-calibration routine based on the Nelder-Mead algorithm, which issues motion commands via infrared and records the resulting trajectories using an off-the-shelf webcam. We show convergence results of the calibration routine and sample trajectories of the swarm robotic platform “Droplet” demonstrating turning and omnidirectional drive.

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ICRA Conference 2014 Conference Paper

Miniature six-channel range and bearing system: Algorithm, analysis and experimental validation

Nicholas Farrow
John Klingner
Dustin Reishus
Nikolaus Correll

We present an algorithm, analysis, and implementation of a six-channel range and bearing system for swarm robot systems with sizes in the order of centimeters. The proposed approach relies on a custom sensor and receiver model, and collection of intensity signals from all possible sensor/emitter pairs. This allows us to improve range calculation by accounting for orientation-dependent variations in the transmitted intensity, as well as to determine the orientation of the emitting robot. We show how the algorithm and analysis generalize to other range and bearing systems, and evaluate its performance experimentally using two ping-pong ball-sized “Droplets” mounted on a precise gantry system.

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