Papers by Brent Gillespie
Bookmarks Related papers MentionsView impact
ABSTRACT In this paper we consider the disturbance response for a heterogeneous string of harmoni... more ABSTRACT In this paper we consider the disturbance response for a heterogeneous string of harmonic oscillators. We assume the individual controllers can communicate with a limited range of neighbors and be tuned independently. Motivated by the speed-dependent spacing policy in vehicle platooning, we develop an extension of the concept of time headway for oscillator systems. Using fundamental limitations theory, we derive a lower bound on the peak magnitude response of the transfer function that describes how a disturbance applied to the lead oscillator propagates along the string to produce a response in the last oscillator. We then give sufficient conditions for string instability in terms of the separation policy, communication ranges, certain time domain performance specifications, and bandwidth limitations.
Bookmarks Related papers MentionsView impact
IEEE Transactions on Neural Systems and Rehabilitation Engineering, 2021
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Haptic shared control is a promising means for combining the best of human manual control with au... more Haptic shared control is a promising means for combining the best of human manual control with automatic control, keeping the human in the loop while avoiding automation pitfalls. In this study, we consider a situation in which both human and the automation system recognize an obstacle but choose different paths of avoidance. While the driver and automation have similar perceptions of the situation, the commands they issue are incompatible and their simple sum is most likely dangerous. To resolve this issue, this study is focused on exploring how roles (i.e. leader and follower) in a haptic collaboration can be negotiated and exchanged between the two partners. Specifically, we test the influence of the timing of cues to promote adoption of leader and follower roles in a shared control task. Preliminary results suggest that haptic feedback can enhance drivability and prevent accidents.
Bookmarks Related papers MentionsView impact
Springer eBooks, 2014
Bookmarks Related papers MentionsView impact
IFAC-PapersOnLine, 2016
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
IEEE Transactions on Robotics and Automation, 2001
Bookmarks Related papers MentionsView impact
Haptics: Science, Technology, and Applications, 2018
The physical mass and damping of a haptic device contribute features that can be considered paras... more The physical mass and damping of a haptic device contribute features that can be considered parasitic in that they potentially mask the virtual environment the user is intended to feel. On the other hand, users are generally able to adapt to the mechanical properties of physical tools and concentrate on the dynamics of task objects in the environment. It would be unsurprising, then, if humans were also able to ignore parasitic effects and focus on the mechanical properties of interest within a rendered environment. In this work, we explore a particular parasitic effect (damping) and its impact on the perception of stiffness. We examine the various perceptual impacts of predictable or unpredictable levels of damping. We find that, overall, humans are quite capable of ignoring damping to focus on stiffness, but that this ability may be hampered in the presence of unpredictable damping.
Bookmarks Related papers MentionsView impact
Plastic and Reconstructive Surgery, 2014
Introduction: Regenerative Peripheral Nerve Interfaces (RPNIs) are neurotized muscle grafts that ... more Introduction: Regenerative Peripheral Nerve Interfaces (RPNIs) are neurotized muscle grafts that control prostheses through electromyography (EMG). RPNI signals have not been quantified during phases of voluntary movements. This study: a) characterizes active RPNI signaling compared to background activity and b) defines the reliability and validity of RPNI function during gait phases of rat walking. Material and Methods: Rat groups were: Control (n=3), RPNI (n=3), Denervated (n=3). Bipolar electrodes were implanted onto the soleus muscles in each group. The Control group was left intact. The Denervated group had the tibial nerve transected. For RPNIs, the soleus muscle was freely grafted to the ipsilateral thigh and neurotized by the transected tibial nerve. While walking on a treadmill, rats were videographed and raw EMG signals were simultaneously recorded. Outcome measurements were integrated EMG (iEMG) and iEMG normalized (NiEMG) to stance, swing, or sit gait phase. Results: Majority of EMG activity was observed within the stance phase—70% for Control and 79% for RPNI—as expected for active soleus postural muscles. Stance NiEMG signals were greater than swing NiEMG averages for Control and RPNI groups (Fig 1). The Denervated group stance and swing NiEMG signals were not different without peripheral nerve control. Fidelity of RPNI stance activity (NiEMG signal to background signal) was 5.6 to 1, or double the Control signal fidelity. Correlations between iEMG and stance time for the Control (r=0.74) and RPNI (r=0.76) indicate strong signal reliability (Fig. 2). Conclusion: Measurements of fidelity, reliability, and validity for RPNI signal detection all exceeded normal probability (p<0.05) during voluntary movement.
Bookmarks Related papers MentionsView impact
SAE Technical Paper Series, 2006
Bookmarks Related papers MentionsView impact
... Page 6. 12.5 Pick the Simplest Explanation A common notion in philosophy, information theory,... more ... Page 6. 12.5 Pick the Simplest Explanation A common notion in philosophy, information theory, and many other disciplines is that the simplest explanation is the best. This is known as Occam&#x27;s Razor (after William of Occham, 12851349). ...
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Drop-foot is an often chronic disability that accompanies hemiparesis in up to 20% of persons wit... more Drop-foot is an often chronic disability that accompanies hemiparesis in up to 20% of persons with history of stroke (Lyons, 2002). It is generally treated by prescribing an anklefoot orthosis (AFO) to immobilize the foot or a portable peroneal stimulator to electrically stimulate active dorsiflexion (Granat, 1996). Therapeutic interventions addressing ankle mobility that employ robotic technology are also coming on-line (Girone, 2001), and could benefit a large number of patients if successful. We propose a ...
Bookmarks Related papers MentionsView impact
Overview: September 1994, 1994
Bookmarks Related papers MentionsView impact
The International Journal of Robotics Research, 2019
Successful soft robot modeling approaches appearing in the recent literature have been based on a... more Successful soft robot modeling approaches appearing in the recent literature have been based on a variety of distinct theories, including traditional robotic theory, continuum mechanics, and machine learning. Though specific modeling techniques have been developed for and validated against already realized systems, their strengths and weaknesses have not been explicitly compared against each other. In this article, we show how three distinct model structures, a lumped-parameter model, a continuum mechanical model, and a neural network, compare in capturing the gross trends and specific features of the force generation of soft robotic actuators. In particular, we study models for fiber-reinforced elastomeric enclosures (FREEs), which are a popular choice of soft actuator and that are used in several soft articulated systems, including soft manipulators, exoskeletons, grippers, and locomoting soft robots. We generated benchmark data by testing eight FREE samples that spanned broad des...
Bookmarks Related papers MentionsView impact
2022 IEEE 5th International Conference on Soft Robotics (RoboSoft)
Bookmarks Related papers MentionsView impact
2006 14th Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems
Bookmarks Related papers MentionsView impact
Uploads
Papers by Brent Gillespie