Inspection Of Walls Research Articles

Non-contact Air Holding Mechanism for Inspection of Pipe Inner Walls

Inspection of pipe inner wall is the most important problem for nuclear power plant. At present there are no non-contact holding technique for the inspection system. For that purpose, we are developing a non-contact inspection system. This paper describes a “first” prototype model of the holder using air pressure, and results of preliminary experiment on air pressure distribution, holding attitude and static holding stiffness. In prototype mechanisms, when the supplied air pressure was 1.2MPa the angle of inclination was within 1', and the holding stiffness was 2 N/μm(air film thickness 100 μm).

An Autonomous Mobile Tracked Vehicle for RFX First Wall Inspection

The design of an inspection system for the RFX first wall is reported. A crossed tracked vehicle is proposed to overcome the problem of possible overturning. The vehicle is equipped with a frontal TV camera and communicates with its off-board control, placed outside the vessel, by means of an umbilical cord which includes signal and power cables and can be used to recover the vehicle in case of failure. Since the inspection will be performed without venting the vessel, all components must be compatible with UHV condition. An insertion system made up of two telescopic elements and a rotating chute was also designed to introduce the vehicle into the vessel in safe conditions.

Noncontact laser sensor for pipe inner wall inspection

This paper describes a noncontact laser sensor for pipe inner wall inspection using the circular optical cutting method. The sensor, consists principally of a laser diode light source, an optical ring pattern generator, and a CCD camera. The generator forms the light from the laser diode into a circular pattern to project on the pipe inner wall. The light reflected or scattered by the pipe inner surface is imaged on the CCD camera. It is possible to select the proper parameters by funda- mental performance analysis and simulation according to the theory of light reflection and scattering. Experiments show that with the sensor mounted on an automated moving system, pipes of interior diameter between 80 and 140 mm can be inspected with resolution of 100 m mi n radius. Analysis of the pipe interior wall surface using wavelet transforms is also described. © 1998 Society of Photo-Optical Instrumentation Engineers. (S0091-3286(98)03205-X)

Non-contact Air Holding Mechanism for Inspection of Pipe Inner Walls.

Inspection of pipe inner wall is the most important problem for nuclear power plant. At present there are no non-contact holding technique for the inspection system. For that purpose, we are developing a non-contact inspection system. This paper describes a “first” prototype model of the holder using air pressure, and results of preliminary experiment on air pressure distribution, holding attitude and static holding stiffness. In prototype mechanisms, when the supplied air pressure was 1.2MPa the angle of inclination was within 1', and the holding stiffness was 2 N/μm(air film thickness 100 μm).

歩行型壁面移動機構の脚／胴体質量比とパワーの関係

Many wall-climbing mechanisms have been developed for inspection of walls of buildings, washing of windows, plant inspection, and so on. It is important to lighten the weight of the wall-climbing mechanism when we design it. Therefore we should use actuators which have minimum power to move the mechanism. We will discuss on a relation of leg and body mass ratio to power demanded for vertical locomotion of the multi-sole biped legged wall-climbing mechanism. In the case of walking mechanisms which move on the horizontal plane, the mass ratio should be zero from a point of energetic efficiency. In the case of wall-climbing mechanisms, a design to minimize the mass ratio is disadvantageous, because, to remove parts from the leg to the body to minimize the mass ratio makes the body heavier and demands more power to move the body. In this paper, the existence of the optimal mass ratio and a design method using the mass ratio is introduced. Additionally, to evaluate the validity of the proposed method, a design example is introduced.

Advances in HDPE barrier walls

The cut-off and/or containment of laterally flowing liquids from landfills and impoundment reservoirs generally utilize some type of vertical wall. The most common wall is constructed using a slurry supported trench, subsequently backfilled with soil-bentonite, soil-cement, cement-bentonite or soil-cement-bentonite. Concerns have arisen as to the installation, inspection and durability of such walls. A different, or complementary, strategy uses a geomembrane by itself or in combination with any one of the standard backfill materials to provide the degree of completeness and environmental safety/security that most, if not all of these sites warrant. This paper discusses applications where geomembrane barrier walls can be used, details of their installation, idiosyncrasies of the material used (particularly the diffusive transport aspect) and concludes with selected comments regarding emerging technology.

Development of wall-climbing robots

The use of a wall-climbing robot for rescue, wall inspection and fire-fighting has been anticipated for a long time. Four quite different robots have been developed in our laboratory. The first robot has a large sucker and the inverse mechanism of a hovercraft. The second type has a biped walking mechanism with a small sucker on each foot. The third can move on an irregular vertical wall by using the thrust force of propellers. This is a wall driving robot. The fourth robot can fly in the air in a short distance whenever it is required. The mechanisms and control systems of these robots are discussed.

Managing multiple construction robots with a computer

The Construction Robotic Equipment Management System (CREMS) prototype presented in this paper has been applied to the evaluation of performance of ten diverse construction robots. individual task characteristics along with the robot physical parameters have been analyzed in arriving at appropriate effectiveness and productivity parameters. The wall inspection, clean room inspection and concrete placement tasks were analyzed using a uniform analysis procedure. The number of erected units has been the primary focus of beam and column erection evaluation. Consistency and relative density were considered as parameters associated with productivity of a robotic excavation control system. Underground utilities encountered during excavation imposed limits on the speed of progress and interruptions along the delivery path of concrete distribution. These are regarded as major project-specific constraints for these tasks. An example application of CREMS to robotic excavation has been provided.

A Wall-Climbing Robot Using Propulsive Force of a Propeller : Mechanism and Control in a Mild Wind

Use of a wall-climbing robot for such purposes as rescue, wall inspection and fire-fighting in high-rise buildings has been anticipated for a long time. Three different types of models have been developed in our laboratory. The present one can move on a wall using the thrust force of propellers, which are inclined slightly toward the wall to produce the frictional force between the wheels and wall surface. It has a long and lightweight body for climbing an irregular wall surface, and its mechanism and the control system by which it can move in calm or mild wind conditions are discussed briefly.

A biped walking robot capable of moving on a vertical wall

The use of a wall-climbing robot for purposes such as rescue, wall inspection and fire-fighting on high-rise buildings has been anticipated for a long time. Three different types of wall-climbing robots have been developed in Japan. The first one has a large area sucker, which has the reverse mechanism of a hovercraft. This type can be used only on flat and wide surfaces. The second one has crawlers to move on a vertical wall with many small suckers on them. The third one has a walking mechanism with small suckers on each foot. A biped walking model was built and tested on a vertical wall and a ceiling. The aerodynamic matching between blower performance and required forces of a sucker, as well as the control systems of the robot, are studied in detail.

A Wall-Climbing Robot Using Propulsive Force of Propeller. 1st Report. Mechanism and Control in a Weak Wind.

Use of a wall-climbing robot for such purposes as rescue, wall inspection and fire fighting in high-rise buildings has been anticipated for a long time. Three quite different types of models have been developed in our laboratory. The present one can move on a wall by using the thrust force of propellers, which are inclined a little to the wall side to produce the frictional force between wheels and wall surface. It has a long and lightweight body to climb up on an irregular wall surface, and its mechanism and the control system by which it can move in a calm or weak wind condition are discussed briefly.

A Practical Evaluation of Nondestructive Tubular Inspection Units: Methods and Results

Summary This paper describes a program for evaluating flaw-detection capabilities of electromagnetic inspection (EMI) and ultrasonic inspection (UT) units used in oil-country tubular goods (OCTG) inspection. The test program involves use of two 7-in. [17.78-cm] joints of casing; each contains various OD and ID defects. The test procedures are similar to those used by other major operators, but the scope, design, and quality-control measures of Chevron's program make it unique. Results are presented for the 73 evaluations conducted to date, which indicate a two-to-one superiority of UT units in flaw-detection capabilities. The relatively poor performance of EMI inspection prompted re-evaluation of the use of this type of service for OCTG body wall inspection.

Mine roof and wall inspection apparatus and method

The roof and walls of a mine are inspected for fissures, channels and other geological structure by use of a vibratory energy transmitter and a vibratory energy receiver each of which are forced into contact with the wall or roof by a jack with little or no loss of vibratory energy. The frequency of vibration is between 10 and 100 kilohertz.

Ultrasonic inspection of pressure vessel welds and walls—mechanised and automated techniques

New collections allow us to describe some new algae forming: a) centimetric, unorganized, masses (Toutinella bifurcata from the Middle Triassic of Provence); b) large, decimetric masses (Zarramanella menorica from the ‘Buntsandstein’ of Minorca, Balearic Islands) and c) interesting, plurispecific biocenosis, laminated and silicified, from the French Massif Central: Lower Stephanian of Saint-Étienne basin (with Hankerpella minima, Baltzerella stephaniense, Ponsinella undulata) and Lower Autunian of Bourbon-l'Archambault basin (Hanskerpella pustulata, Baltzerella stephaniense, Ponsinella multifrons, Sarfatigirella intricata). Other forms are badly preserved, one is possibly a Broutinella sp. and another may be a coccoid form of cyanobacteria or chlorophyceae. Silicified biocenoses macroscopically occur in the form of regular laminations, exhibiting vertical, planar joints (1–2 cm wide) and horizontal, planar joints, 5 mm to 3 cm thick, with various sedimentary infillings. These facies represent early and late silicifications of biological felts (mats), probably previously partly calcified and affected by desiccation cracks partly infilled before the silicification. There is no evidence for an early silicification of living filaments and trichomes. The silicification also affects other types of sediments (petites, sandstones, conglomerates, breccias) associated with the algal formations. Macroscopically, these laminated formations do not show domes or hemispheres; on the other hand, these features clearly appear under the microscope, and these formations are true stromatolites. The basins of Saint-Étienne and Bourbon-l'Archambault contain volcanic rocks; the siliceous series, very localized in the basins, represent an impregnation of various primary materials by silica of hydrothermal origin. The present study is voluntarily limited to the palaeontological and palaeoecological appearances; algal laminations formed in ephemeral pools and small lakes, under very particular conditions, ‘hydrothermal’ sensu lato, are still to be stated more precisely.Des récoltes nouvelles permettent de décrire quelques algues nouvelles formant des amas centimétriques non organisés (Toutinella bifurcata du Trias moyen de Provence), de grosses masses décimétriques (Zarmmanella menorica du ≪ Buntsandstein ≫ de Minorque) et d'intéressantes biocrenoses plurispécifiques laminées et silicifiées du Massif central français: Stephanien inférieur de Saint-Étienne (à Hankerpella minima, Baltzerella stephaniense, Ponsinella undulata), Autunien inférieur du bassin de Bourbon-l'Archambault (Hanskerpella pustulata, Baltzerella stephaniense, Ponxinella multifrons, Sarfatigirella intricata). D'autres formes sont mal conservées, l'une serait attribuables à une ? Broutinella sp. et une autre à une coccoide (cyanobactéries ou chlorophycées). Les biocœnoses silicificées se présentent macroscopiquement sous forme de laminations régulières, accidentées de fentes planes verticales (1–2 cm de largeur) et de fentes planes horizontales (5 mm–3 cm de hauteur), à remplissages sédimentaires variés. Ces faciès correspondent à des silicifications précoces et tardives de feutres biologiques probablement en grande partie calcifiés précocement et affectés de fentes de dessiccation partiellement remplies avant la silicification. Aucun indice de silicification de filaments et de trichomes du vivant des organismes n'a pu être observé. La silicification affecte aussi d'autres sédiments (pélites, grès, conglomérats, brèches), associés aux anciennes formations algaires. Macrospiquement, ces formations laminées ne montrent pas de dômes ni d'hémisphères; en revanche ces structures apparaissent parfaitement au microscope, et ce sont de véritables stromatolites. Les bassins de Saint-Étienne el de Bourbon-l'Archambault contiennent des formations volcaniques; les formations siliceuses, qui sont très localisées dans les bassins, correspondent certainement à une imprégnation par de la silice d'origine hydrothermale de sédiments variés. La présente étude se limite volontairement à l'aspect paléontologique et paléoécologique; les laminations algaires se sont formées dans des bassins ou de petits lacs éphémères, dans des conditions très particulières, ≪ hydrothermales ≫ sensu lato, encore à préciser.