Positional Control with Biological Clocking

2021 ◽  
Author(s):  
Gopal Tadepalli
Keyword(s):  
Positional Control

scholarly journals Joint speed feedback improves myoelectric prosthesis adaptation after perturbed reaches in non amputees

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Eric J. Earley ◽  
Reva E. Johnson ◽  
Jonathon W. Sensinger ◽  
Levi J. Hargrove
Keyword(s):  
Sensory Feedback ◽  
Feedforward Control ◽  
Feedback System ◽  
Augmented Feedback ◽  
Myoelectric Prosthesis ◽  
Reaching Task ◽  
Prosthesis Control ◽  
High Uncertainty ◽  
Relevant Factors ◽  
Positional Control

AbstractAccurate control of human limbs involves both feedforward and feedback signals. For prosthetic arms, feedforward control is commonly accomplished by recording myoelectric signals from the residual limb to predict the user’s intent, but augmented feedback signals are not explicitly provided in commercial devices. Previous studies have demonstrated inconsistent results when artificial feedback was provided in the presence of vision; some studies showed benefits, while others did not. We hypothesized that negligible benefits in past studies may have been due to artificial feedback with low precision compared to vision, which results in heavy reliance on vision during reaching tasks. Furthermore, we anticipated more reliable benefits from artificial feedback when providing information that vision estimates with high uncertainty (e.g. joint speed). In this study, we test an artificial sensory feedback system providing joint speed information and how it impacts performance and adaptation during a hybrid positional-and-myoelectric ballistic reaching task. We found that overall reaching errors were reduced after perturbed control, but did not significantly improve steady-state reaches. Furthermore, we found that feedback about the joint speed of the myoelectric prosthesis control improved the adaptation rate of biological limb movements, which may have resulted from high prosthesis control noise and strategic overreaching with the positional control and underreaching with the myoelectric control. These results provide insights into the relevant factors influencing the improvements conferred by artificial sensory feedback.

Productive Method and System to Control Dimensional Uncertainties at Final Assembly Stages in Ship Production

1992 ◽  
Vol 8 (04) ◽  
pp. 244-249
Author(s):  
Markku Manninen ◽  
Jarl Jaatinen
Keyword(s):  
Reference System ◽  
Control Methods ◽  
Control Case ◽  
System Study ◽  
Accuracy Control ◽  
Labor Costs ◽  
Dimensional Control ◽  
Final Assembly ◽  
Productive Method ◽  
Positional Control

Strict dimensional control of interim products through the different assembly stages is vitally important for profitable ship production [1].3 Studies in Finland show that a 30% reduction in labor costs is possible in hull construction [2]. This reduction can be gained by eliminating unnecessary fitting and reworking using tight accuracy control methods. This paper presents a method for dimensional control of block assemblies. The dimensional control is thereby separated from the positional control of the block. The method is a 3D-coordinate-based approach relative to a positional reference system. Also described is a real dimensional control case and an evaluation of different measurement technologies in performing the proposed task. The evaluation is comparable to a 1990 system study performed at NASSCO in San Diego [4],

Em Induction And Magnetic Surveys At Large Landfill Sites Using Gps For Positional Control

1996 ◽  
Author(s):  
Jeffrey B. Hackworth ◽  
Thomas M. Kirkpatrick ◽  
D. Randal Holtzclaw
Keyword(s):  
Landfill Sites ◽  
Em Induction ◽  
Positional Control

Positional Control of Crystal Grains in Silicon Thin Film Utilizing Cage-Shaped Protein

2011 ◽  
Vol 50 (4) ◽  
pp. 04DL12 ◽  
Author(s):  
Yosuke Tojo ◽  
Atsushi Miura ◽  
Ichiro Yamashita ◽  
Yukiharu Uraoka
Keyword(s):  
Thin Film ◽  
Silicon Thin Film ◽  
Crystal Grains ◽  
Positional Control

The position of regenerating cambia: auxin/sucrose ratio and the gradient induction hypothesis

1978 ◽  
Vol 203 (1151) ◽  
pp. 153-176 ◽  
Keyword(s):  
Control System ◽  
Induction Hypothesis ◽  
Sucrose Concentration ◽  
Vascular Differentiation ◽  
Concentration Gradients ◽  
Published Evidence ◽  
Different Types ◽  
Source And Sink ◽  
Positional Control

To account for the positions in which vascular cambia regenerate in wound callus, a gradient induction hypothesis was proposed in 1961 in terms of gradients in ‘some factor as yet unknown’. It now seems likely that the gradient is based on morphogen diffusion between source and sink on opposite sides of existing cambia, with morphogen diffusing into the adjoining wound callus. It is specifically proposed that there are two morphogens, auxin diffusing centrifugally and sucrose diffusing centripetally. The cambium then regenerates along a path where the ratio of auxin to sucrose concentration is similar to that at the original cambium, and its orientation (as regards xylem and phloem formation) is determined by the direction of the gradient in this ratio. These proposals are supported by published evidence on auxin and sucrose concentration gradients across the cambium, and on their sources, movements, and known effects on vascular differentiation. Simulations of the proposed positional control system predict patterns of cambial regeneration and orientation corresponding to those observed in four different types of would and graft.

Wireless Nerve Positional Control of Prosthetic Device

2011 ◽  
Author(s):  
David R. Loker ◽  
Yi Wu ◽  
Margaret A. Voss ◽  
John T. Roth ◽  
Stephen A. Strom
Keyword(s):  
Feasibility Study ◽  
Servo Motor ◽  
Prosthetic Device ◽  
Prosthetic Devices ◽  
Wireless Receiver ◽  
Pulse Width Modulated ◽  
Nerve Signal ◽  
Emg Control ◽  
Wireless Transmitter ◽  
Positional Control

Artificial limb control is an active area of research, and the control of prosthetic devices using electromyographic (EMG) interfaces is well established. The authors have previously performed a feasibility study which demonstrated that wireless nerve control of a prosthetic device is possible. This is critical for injuries that result in the loss of muscle which prevent EMG control. The purpose of this study is to extend the authors’ current research by providing enhancements to the system designed in the feasibility study. The objective of this current study is to take simulated nerve signals and transform them into corresponding positional motion control realized by a servo motor. The system designed has four functioning blocks: artificial nerve signal generation, wireless transmitter, wireless receiver, and servo motor. The artificial nerve generator used a PIC microcontroller to simulate and apply the signals directly to the wireless transmitter. A one-byte message, that indicated when the appropriate signal characteristics were met, was wirelessly transmitted. After receiving the message, the wireless receiver sent a corresponding pulse-width modulated (PWM) signal to the servo motor for positional control. Various input signal combinations were used to test the system.

The role of augmented reality in robotics

2020 ◽  
Vol 47 (6) ◽  
pp. 789-794
Author(s):  
Robert Bogue
Keyword(s):  
Augmented Reality ◽  
Design Methodology ◽  
Haptic Feedback ◽  
Historical Background ◽  
Content Type ◽  
Virtual Fixtures ◽  
Research Activities ◽  
Insight Into ◽  
Positional Control

Purpose The purpose of this paper is to provide an insight into how augmented reality (AR) technologies are being applied to robotics. Design/methodology/approach Following an introduction and a brief historical background to AR, this first provides examples of AR applications in robot programming. It then gives examples of recent research into AR-based robot teleoperation. Research activities involving the virtual fixtures (VF) technique are then discussed and finally, brief conclusions are drawn. Findings Because AR concepts were first investigated in the 1990s, applications involving robotics have been widely studied. Programming with the aid of AR devices, such as the HoloLens headset, can be simplified and AR methods, including the VF technique, can improve the accuracy and speed of teleoperation, manipulation and positional control tasks. They can also provide visual or haptic feedback which leads to more intuitive operation and significantly reduces the cognitive load on the operator. Originality/value This provides an insight into the growing role of AR in robotics by providing examples of recent research in a range of applications.

scholarly journals Positional control of mesoderm movement and fate during avian gastrulation and neurulation

1992 ◽  
Vol 193 (3) ◽  
pp. 249-256 ◽  
Author(s):  
Virginio Garcia-Martinez ◽  
Gary C. Schoenwolf
Keyword(s):  
Positional Control
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