Mooring Chain Climbing Robot For Ndt Inspection Applications

Inspection of mooring chains is a dangerous and costly procedure covering inspection above and below the waterline. The paper presents initial results from the RIMCAW project which was aimed at designing and building an inspection robot able to climb mooring chains and deploy NDT technologies for scanning individual links thereby to detecting critical defects. The paper focuses on the design and realisation of the inch worm type novel crawler developed and tested in the TWI Middlesbrough water tank

Development of LPV models and switching LPV-H ? controller for a hydraulic system

This paper describes the development of linear parameter varying (LPV) models and an LPV-H ? controller for one degree of freedom (DoF) electro-hydraulic systems. A virtual set-up consists of a hydraulic actuator driven by a servovalve and supplied from a constant-pressure power unit. The LPV models are derived based on two techniques: black-box modeling and the analytical description of the system (white box modeling). Both methods are compared to each other and the derived models have been used for the design of the switching LPV-H? controller. Simulation results indicate predominance of adapting LPV framework to a hydraulic system control over conventional approaches.Scopu

Design of a hydraulic ankle-foot orthosis

This paper presents the design and simulation of an ankle-foot orthosis (AFO) to assist human walking. Design requirements were established based on a quantitative study of published data, simulations of human walking, and a model of intrinsic and reflex ankle joint stiffness. The design of an AFO that meets these requirements is then presented; it comprises a small linear, hydraulic actuator, a servo-valve, a hydraulic power supply, and an accumulator. Two methods of selecting the kinematic parameters of the AFO are introduced. One is based on force minimization and the other on compactness maximization. The performance expected of the AFO is demonstrated in a simulation study. 2016 IEEE.Scopu

An EMG signal processing system for control of an ankle-foot orthosis

This paper presents an electromyographic (EMG)based digital processing system for estimating foot direction of motion and force exerted from muscles of the human lower leg. This information can be used in the control frameworks of ankle-foot orthoses (AFOs). In essence, it is usually necessary to estimate the ankle's muscles voluntary contraction (VC) and user's intention of motion in order to control an AFO in a reliable and effective way. Consequently, a data processing system is developed that can designate these parameters from EMG signals. The voluntary contraction is calculated based on the root mean square (RMS) of EMG signals, and the direction of motion is estimated by using a feature-based classifier. The experiments are performed on five healthy, sitting subjects and the methodology consists of selecting discriminative features and using basic classifiers. The results of this work show that the direction of motion can be estimated in real-time with high accuracy. 1 2017 IEEE.This publication was made possible by NPRP grant No. 6-463-2-189 from the Qatar National Research Fund (a member of The Qatar Foundation). The statements made herein are solely the responsibility of the authors.Scopu

The characterization of the kinematic and dynamic properties of the ankle joint for an artificial ankle joint design

The kinematic and dynamic properties of the ankle joint (talocrural region) in normal subjects provide important information for the design of rehabilitation robots, below-knee prostheses, ankle-foot orthoses, and exoskeletons. This paper presents a quantitative analysis of published experimental data, simulation studies of human gait, and a dynamic model of ankle joint intrinsic and reflex stiffness to determine design requirements for such ankle devices to operate in the sagittal plane (i.e. ankle plantarflexion/dorsiflexion). The design requirements are derived in terms of average torque, rotatum, range of motion, velocity, acceleration, system bandwidth, torque-velocity curve, and the torque probability density function. 2016 IEEE.Scopu

Mooring Chain Climbing Robot For Ndt Inspection Applications

Inspection of mooring chains is a dangerous and costly procedure covering inspection above and below the waterline. The paper presents initial results from the RIMCAW project which was aimed at designing and building an inspection robot able to climb mooring chains and deploy NDT technologies for scanning individual links thereby to detecting critical defects. The paper focuses on the design and realisation of the inch worm type novel crawler developed and tested in the TWI Middlesbrough water tank