922 research outputs found
Neuro fuzzy control of the FES assisted freely swinging leg of paraplegic subjects
The authors designed a neuro fuzzy control strategy for control of cyclical leg movements of paraplegic subjects. The cyclical leg movements were specified by three `swing phase objectives', characteristic of natural human gait. The neuro fuzzy controller is a combination of a fuzzy logic controller and a neural network, which makes the controller self tuning and adaptive. Two experiments have been performed, in which the performance of the neuro fuzzy control strategy has been compared with conventional PID control strateg
Towards an application of muon scattering tomography as a technique for detecting rebars in concrete
Inspection of the world's ageing population of reinforced concrete infrastructure is a multi-billion dollar problem. Historically, it has not been uncommon for structures to deviate from their designs,or for design drawings to be lost. This leaves asset managers the challenging task of making structural health assessments and maintenance decisions with incomplete knowledge. While current techniques for detecting rebars in concrete are typically limited to penetration depths of less than 50 cm, muon scattering tomography (MST) is a non-destructive, non-invasive technique which shows great promise for high-depth 3D concrete imaging. This paper uses Monte Carlo simulations to demonstrate that MST can be used to detect and locate 100 cm length rebars with a diameter of 33.7 ± 7.3 mm independently of the rebar's location within a concrete structure. This corresponds to a volume of inclusion of 894 ± 386 cm3. The volume of the inclusion can be reconstructed with a resolution of 5.4 ± 0.3% for volumes above 2 500 cm3. It is furthermore demonstrated that 30 mm diameter rebars can be distinguished as two separate objects provided their separation is more than 40â60 mm, and that single and double layers of rebars are distinguishable using the technique. It is anticipated that MST could inform practical studies which support more informed maintenance and modeling, eventually allowing digital twins to be created for a larger subset of historical steel and concrete structures
A Study of the Radiation Tolerance of CVD Diamond to 70MeV Protons, Fast Neutrons and 200MeV Pions
Discrimination of high-Z materials in concrete-filled containers using Muon Scattering Tomography
Development of muon scattering tomography for a detection of reinforcement in concrete
Inspection of ageing, reinforced concrete structures is a world-wide
challenge. Existing non-destructive evaluation techniques in civil and
structural engineering have limited penetration depth and don't allow to
precisely ascertain the configuration of reinforcement within large concrete
objects. The big challenge for critical infrastructure (bridges, dams, dry
docks, nuclear bioshields etc.) is understanding the internal condition of the
concrete and steel, not just the location of the reinforcement. In most new
constructions the location should be known and recorded in the as-built
drawings, where these might not exist due to poor record keeping for older
structures. Muon scattering tomography is a non-destructive and non-invasive
technique which shows great promise for high-depth 3D concrete imaging.
Previously, we have demonstrated that individual bars with a diameter of 33.7
+- 7.3 mm at 50 cm depth can be located using muon scattering tomography. Here
we present an improved method that exploits the periodicity of bar structures.
With this new method, reinforcement with bars down to 6 mm thickness can be
detected and imaged
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