scholarly journals Transparent Data Reduction in Networked Telepresence and Teleaction Systems. Part I: Communication without Time Delay

2007 ◽  
Vol 16 (5) ◽  
pp. 523-531 ◽  
Author(s):  
Sandra Hirche ◽  
Peter Hinterseer ◽  
Eckehard Steinbach ◽  
Martin Buss
Keyword(s):  
Time Delay ◽  
Data Reduction ◽  
Network Traffic ◽  
Human Perception ◽  
Signal Amplitude ◽  
Perception Threshold ◽  
Control Approach ◽  
Novel Approach ◽  
Communication Time ◽  
Video And Audio

Limited communication resources represent a major challenge in networked tele-presence and teleaction systems. Video and audio compression schemes are well advanced employing models of human perception. In contrast to that haptic data reduction schemes are rather poorly treated in the known literature. This article introduces a novel approach to reduce network traffic in haptic telepresence systems exploiting limits in human haptic perception. With the proposed deadband control approach, data packets are transmitted only if the signal change exceeds a signal amplitude dependent perception threshold. Experimental user studies show that an average network traffic reduction of up to 85% can be achieved without significantly impairing the perception of the remote environment. The assumption throughout this article is that there is no communication time delay.

scholarly journals Transparent Data Reduction in Networked Telepresence and Teleaction Systems. Part II: Time-Delayed Communication

2007 ◽  
Vol 16 (5) ◽  
pp. 532-542 ◽  
Author(s):  
Sandra Hirche ◽  
Martin Buss
Keyword(s):  
Time Delay ◽  
Data Reduction ◽  
Network Traffic ◽  
Data Transmission ◽  
Threshold Value ◽  
Control Methods ◽  
Control Approach ◽  
Novel Approach ◽  
Traffic Reduction ◽  
Remote Environment

Two of the major challenges in networked haptic telepresence and teleaction systems are the time delay associated with the data transmission over the network and the limited communication resources. Sophisticated control methods are available for the stabilization in the presence of time delay. The reduction of haptic network traffic, however, is only poorly treated in the known literature. Data reduction approaches for time delayed haptic telepresence are not available at all. This article presents a novel approach to reduce the network traffic in haptic telepresence systems with constant (unknown) time delay. With the proposed deadband control approach data are sent only if the signal to transmit changes more than a given threshold value. In order to guarantee stability with time delay and data reduction a well-known time delay approach, the scattering transformation, is extended. Experimental user studies show that an average network traffic reduction up to 96% is achieved without significantly impairing the perception of the remote environment compared to the standard approach with time delay.

Intelligent Approach to Floor Vibration Control

2005 ◽  
Author(s):  
Janice L. Martell ◽  
Arya Ebrahimpour ◽  
Marco P. Schoen
Keyword(s):  
Cantilever Beam ◽  
Human Perception ◽  
Shopping Mall ◽  
Optimal Placement ◽  
Sensors And Actuators ◽  
Control Approach ◽  
Novel Approach ◽  
Floor Vibration ◽  
High Level ◽  
Floor System

Genetic Algorithms (GAs) have been used to solve a multiple of engineering problems with the civil engineering applications ranging from optimal placement of sensors and actuators on structures to pipeline layouts. GAs are especially useful in finding optimal solutions to problems that have many parameters with complex search spaces and a high level of interaction among the describing parameters. The novel experimental control approach presented in this paper uses a GA and a piezoelectric actuator to control the vibration of an aluminum cantilever beam. This set-up is based on a floor vibration problem, where the human perception of vibration dictates the sensitivities in the cost function of the GA. Lightweight floors can be excited by occupant activities such as walking, jumping and dancing. Humans are especially sensitive to vibrations in the range of 4 to 8 Hz. The occupancy of a floor system — whether the floor is used in an office, a shopping mall, or a ballroom — determines the degree to which humans are annoyed by the vibration. In this paper, the GA based control limits the peak acceleration within a predefined bandwidth. Since the cantilever beam has a higher natural frequency than a lightweight floor system a bandwidth of approximately 1.6–15.9 Hz (10–100 rad/s) is used as the frequency range to control. The control to be designed will be a genetic algorithm-robust controller. The analytical results indicate that this novel approach works well.

scholarly journals An Efficient Real-Time NMPC for Quadrotor Position Control under Communication Time-Delay

2020 ◽  
Author(s):  
Barbara Barros Carlos ◽  
Tommaso Sartor ◽  
Andrea Zanelli ◽  
Gianluca Frison ◽  
Wolfram Burgard ◽  
...  
Keyword(s):  
Time Delay ◽  
Real Time ◽  
Position Control ◽  
Communication Time

Research on Parallel PZT Phased Array Based Structural Health Monitoring in CFPR

2013 ◽  
Vol 753-755 ◽  
pp. 2343-2346
Author(s):  
Ya Jie Sun ◽  
Yong Hong Zhang ◽  
Hui Qiang Tang ◽  
Cheng Shan Qian ◽  
Shen Fang Yuan
Keyword(s):  
Time Delay ◽  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Lamb Wave ◽  
Phased Array ◽  
Signal Amplitude ◽  
Gray Scale ◽  
One Dimensional ◽  
Structural Health ◽  
Damage Location

Phased array theroy can controll the Lamb wave beem steering in certain range by adding the time delay to the signals. Phased array theory is used to identify the damge in the structure. One dimensional PZT array is restricted in monitoring distance. Two parellel PZT sensors arrays are utilized to monitor the CFPR structure to extend the monitoring distance and to improve the precision of the damage locatilization. The experiment is done on the CFPR structure by using two parellel PZT arrays to detect the damage in the structure. The results of the experiment is shown on the mapped image. Gray-scale in the mapped image from dark to light corresponds to the signal amplitude from low to high. The highlight of the mapped image is the damage location in the structure. The monitoring results in the CFPR structure by two parellel PZT arrays is accurate and identical.

Generic Modular Operations for Virtual Manufacturing Process Engineering

1997 ◽  
Author(s):  
David E. Lee ◽  
H. Thomas Hahn
Keyword(s):  
Manufacturing Process ◽  
Process Development ◽  
Process Engineering ◽  
Virtual Manufacturing ◽  
Control Approach ◽  
Computational Costs ◽  
Direct Mechanism ◽  
Novel Approach ◽  
Operation Control ◽  
Virtual Process

Abstract In order to address the computational costs of modeling and analyzing manufacturing processes, a novel approach to virtual manufacturing process engineering using generic modular operations is presented. Relying on a state based representation of operation control for a simplified virtual manufacturing workcell, the valid states for each sequence of generic modular operations are aggregated and both operation state and processing constraints applied to specify the subtasks required to complete each step in a product’s process plan. By adopting this state based control approach, virtual process engineering provides a direct mechanism to map virtual process representations onto actualized processes. Using these generic modular operations and their temporal and processing dependencies, the computationally complex elements of virtual manufacturing process simulation can be directly identified and an architecture for virtual process development specified. Examples from both machining and assembly processes are provided.

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