The Berkeley Lower Extremity Exoskeleton

2005 ◽  
Vol 128 (1) ◽  
pp. 14-25 ◽  
Author(s):  
H. Kazerooni ◽  
R. Steger
Keyword(s):  
Lower Extremity ◽  
Control Algorithm ◽  
Local Area Network ◽  
Control Method ◽  
Local Area ◽  
Area Network ◽  
System Sensitivity ◽  
Trade Offs ◽  
Control Schemes ◽  
Definition Of

The first functional load-carrying and energetically autonomous exoskeleton was demonstrated at the University of California, Berkeley, walking at the average speed of 1.3m∕s(2.9mph) while carrying a 34kg(75lb) payload. Four fundamental technologies associated with the Berkeley lower extremity exoskeleton were tackled during the course of this project. These four core technologies include the design of the exoskeleton architecture, control schemes, a body local area network to host the control algorithm, and a series of on-board power units to power the actuators, sensors, and the computers. This paper gives an overview of one of the control schemes. The analysis here is an extension of the classical definition of the sensitivity function of a system: the ability of a system to reject disturbances or the measure of system robustness. The control algorithm developed here increases the closed-loop system sensitivity to its wearer’s forces and torques without any measurement from the wearer (such as force, position, or electromyogram signal). The control method has little robustness to parameter variations and therefore requires a relatively good dynamic model of the system. The trade-offs between having sensors to measure human variables and the lack of robustness to parameter variation are described.

Vehicle-to-Pedestrian Communication Modeling and Collision Avoiding Method in Connected Vehicle Environment

2017 ◽  
Vol 2621 (1) ◽  
pp. 21-30 ◽  
Author(s):  
Shuxian He ◽  
Jiangchen Li ◽  
Tony Z. Qiu
Keyword(s):  
Stochastic Model ◽  
Wireless Local Area Network ◽  
Local Area Network ◽  
Control Method ◽  
Pedestrian Safety ◽  
Local Area ◽  
Area Network ◽  
Connected Vehicle ◽  
Proposed Model ◽  
Generalized Framework

A generalized framework consisting of a stochastic model, a responsive control method, and typical scenarios using vehicle-to-pedestrian (V2P) communication is proposed to improve pedestrian safety. The proposed stochastic model formulates various effects of uncertainties in a V2P communication system. The responsive control method is used to improve pedestrian safety under V2P communication conditions. Results show that adopting only Bluetooth or Wi-Fi (wireless local area network) technology, which has a high establishment time, is not sufficient for V2P communication, whereas dedicated short-range communication (DSRC) featuring low latencies meets requirements. A case study in the field was conducted to evaluate the feasibility of responsive control; it was concluded that with the use of the proposed model and the responsive control method, Bluetooth technology combined with DSRC could be workable for active pedestrian protection.

A Generalized TCP Fairness Control Method for Multiple-Host Concurrent Communications in Elastic WLAN System Using Raspberry Pi Access Point

2020 ◽  
Vol 11 (2) ◽  
pp. 18-40
Author(s):  
Rahardhita Widyatra Sudibyo ◽  
Nobuo Funabiki ◽  
Minoru Kuribayashi ◽  
Kwenga Ismael Munene ◽  
Hendy Briantoro ◽  
...  
Keyword(s):  
Wireless Local Area Network ◽  
Local Area Network ◽  
Control Method ◽  
Access Point ◽  
Local Area ◽  
Packet Transmission ◽  
Raspberry Pi ◽  
Area Network ◽  
Traffic Demand ◽  
Tcp Fairness

The IEEE802.11n wireless local-area network (WLAN) has been widely adopted due to the flexible coverage and lower installation cost. However, the TCP throughput unfairness was detected when multiple hosts concurrently communicate with a single access-point (AP). Previously, the authors proposed the TCP fairness control method for only two hosts in the elastic WLAN system using Raspberry Pi AP, which dynamically adapts the topology according to the traffic demand. The delay is introduced in the packet transmission to the faster host from the AP, which is optimized by the PI feedback control such that the measured throughput becomes equal between the hosts. In this paper, the authors proposed a generalization of this method for any number of hosts by newly introducing the target throughput as the equal goal among the hosts. It is dynamically updated using the measured throughputs. The effectiveness of the proposal is verified through experiments using the elastic WLAN system testbed with one AP and up to four hosts.

Local Area Networks

2011 ◽  
pp. 550-558
Author(s):  
Raymond A. Hansen ◽  
Phillip T. Rawles
Keyword(s):  
High Speed ◽  
Local Area Network ◽  
Local Area Networks ◽  
Geographic Area ◽  
Local Area ◽  
Data Networks ◽  
Area Network ◽  
End User ◽  
Actual Meaning ◽  
Definition Of

Local area networks (LAN) are extremely popular in both the consumer and enterprise markets. The LAN has become ubiquitous throughout both of these markets as the Internet has grown in size and use, PCs have become readily available at an attractive price point, and high-speed broadband connections have become readily available. Yet, with all the usage of LANs for connecting computer equipment of all types, there is no standard, formal industry accepted definition for a local area network (Comer, 2006, 15). According to the Institute of Electrical and Electronics Engineers (IEEE), a local area network is describes as being “distinguished from other types of data networks in that they are optimized for a moderate-sized geographic area, such as a single office building, a warehouse, or a campus” (2001). Some definitions include a distinction concerning physical proximity (Palmer & Sinclair, 2003, 2), while others provide definitions based on topology, physical medium, or performance characteristics. Vendors, governing/standards bodies, and even network managers have yet their own definition of the exact meaning of what a local area network is and means. These definitions tend to use terminology loosely and allow the end user to determine actual meaning based on context and technologies used. The following discussion will give the reader the foundational information of LANs, including LAN addressing (both MAC and IP addressing), architecture, and protocols.

Strathnet—a local area network

1981 ◽  
Vol 1 (1) ◽  
pp. 21 ◽  
Author(s):  
David Hutchison ◽  
Doug Shepherd
Keyword(s):  
Local Area Network ◽  
Local Area ◽  
Area Network

A Local Area Network for Medical Research; Planning, Realization and Experience

1991 ◽  
Vol 30 (01) ◽  
pp. 53-64 ◽  
Author(s):  
R. Schosser ◽  
C. Weiss ◽  
K. Messmer
Keyword(s):  
Medical Research ◽  
Word Processing ◽  
Local Area Network ◽  
Local Area ◽  
Area Network ◽  
Test Installation ◽  
Cost Performance ◽  
The Public ◽  
On Line ◽  
The University

This report focusses on the planning and realization of an interdisciplinary local area network (LAN) for medical research at the University of Heidelberg. After a detailed requirements analysis, several networks were evaluated by means of a test installation, and a cost-performance analysis was carried out. At present, the LAN connects 45 (IBM-compatible) PCs, several heterogeneous mainframes (IBM, DEC and Siemens) and provides access to the public X.25 network and to wide-area networks for research (EARN, BITNET). The network supports application software that is frequently needed in medical research (word processing, statistics, graphics, literature databases and services, etc.). Compliance with existing “official” (e.g., IEEE 802.3) and “de facto” standards (e.g., PostScript) was considered to be extremely important for the selection of both hardware and software. Customized programs were developed to improve access control, user interface and on-line help. Wide acceptance of the LAN was achieved through extensive education and maintenance facilities, e.g., teaching courses, customized manuals and a hotline service. Since requirements of clinical routine differ substantially from medical research needs, two separate networks (with a gateway in between) are proposed as a solution to optimally satisfy the users’ demands.

Link-Level Simulator for Wireless local Area Network

2018 ◽  
Vol 6 (7) ◽  
pp. 314
Author(s):  
Chaithra. H. U ◽  
Vani H.R
Keyword(s):  
Wireless Local Area Network ◽  
Local Area Network ◽  
Local Area Networks ◽  
Local Area ◽  
Long Term Evolution ◽  
Wireless Local Area Networks ◽  
Area Network ◽  
Network Simulator ◽  
Term Evolution

Now a days in Wireless Local Area Networks (WLANs) used in different fields because its well-suited simulator and higher flexibility. The concept of WLAN  with  advanced 5th Generation technologies, related to a Internet-of-Thing (IOT). In this project, representing the Network Simulator (NS-2) used linked-level simulators for Wireless Local Area Networks and still utilized IEEE 802.11g/n/ac with advanced IEEE 802.11ah/af technology. Realization of the whole Wireless Local Area Networking linked-level simulators inspired by the recognized Vienna Long Term Evolution- simulators. As a outcome, this is achieved to link together that simulator to detailed performances of Wireless Local Area Networking with Long Term Evolution, operated in the similar RF bands. From the advanced 5th Generation support cellular networking, such explore is main because different coexistences scenario can arise linking wireless communicating system to the ISM and UHF bands.

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