Inspection Camera Research Articles

A pipe-profiling adapter for CCTV inspection cameras: development of a pipe-profiling instrument

The principle of the optical section has been used to develop a profiling attachment for CCTV pipe inspection cameras. A light source, placed in front of the camera, projects a ring of light onto the pipe wall, which is then viewed by the camera. Any distortion in the pipe wall will be made visible by the light ring. The CCTV image is digitized by an electronic frame grabber and the light ring image is located by specially developed pattern-matching software. The light ring shape is then analysed mathematically using a radial descriptor, which allows any distortion to be represented in terms of a Fourier series. The device has been tested in the laboratory and in the field, and has been used to examine pipe degradation both in sewers and in water mains.

A linear array position sensitive detector based on amorphous silicon

A linear array thin film position sensitive detector (LTFPSD) based on hydrogenated amorphous silicon (a-Si:H) is proposed for the first time. Taking advantage of the optical properties presented by a-Si:H devices, we have developed a LTFPSD with 128 integrated elements able to be used in 3D inspections/measurements. Each element consists of a one-dimensional LTFPSD, based on a p-i-n diode produced in a conventional PECVD system, where the doped layers are coated with thin resistive layers to establish the required device equipotentials. By proper incorporation of the LTFPSD into an optical inspection camera it will be possible to acquire information about an object/surface, through the optical cross-section method. The main advantages of this system, when compared with the conventional CCDs, are the low complexity of hardware and software used and that the information can be continuously processed (analog detection).

A New Linear Array Thin Film Position Sensitive Detector (LTFPSD) for 3D Measurements

ABSTRACTA Linear array Thin Film Position Sensitive Detector (LTFPSD) based on hydrogenated amorphous silicon (a-Si:H) is proposed for the first time, taking advantage of the optical properties presented by a-Si:H devices we have developed a LTFPSD with 128 integrated elements able to be used in 3D inspections/measurements. Each element consists on an one-dimensional TFPSD, based on a p.i.n diode produced in a conventional PECVD system, where the doped layers are coated with thin resistive layers to establish the required device equipotentials. By proper incorporation of the LTFPSD into an optical inspection camera it will be possible to acquire information about an object/surface, through the optical cross-section method1. The main advantages of this system, when compared with the conventional CCDs, are the low complexity of hardware and software used and that the information can be continuously processed (analogue detection).

Laser scanning cameras for in-reactor inspection : Adrain, R.S.; Armour, I.A.; Bach, J.H. Sensor Review, Vol. 7, No. 2, pp. 68–76 (Apr. 1987)

Laser scanning cameras for in-reactor inspection : Adrain, R.S.; Armour, I.A.; Bach, J.H. Sensor Review, Vol. 7, No. 2, pp. 68–76 (Apr. 1987)

Remote maintenance of in-vessel components in Tokamak Fusion Test Reactor

The Tokamak Fusion Test Reactor (TFTR) will generate a total of 3 × 10 21 neutrons during its planned D-T operational period. A maintenance manipulator has been designed and tested to minimize personnel radiation during in-vessel maintenance activities. Its functions include visual inspection, first-wall tile replacement, cleaning, diagnostics calibrations and leak detection. To meet these objectives, the TFTR maintenance manipulator is required to be operable in the TFTR high vacuum environment, typically < 1 × 10 −8 torr, (< 10 −6 Pa). Geometrically, the manipulator must extend 180° either direction around the torus to assure complete coverage of the vessel first-wall. The manipulator consists of a movable carriage assembly, a non-articulated link section mounted on the carriage, and six movable articulated link sections which are driven by electrical actuators. The boom has vertical load capacity of 455 kg and lateral load capacity of 46 kg. The boom can either be outfitted with a general inspection arm or dexterous slave arms. The general inspection arm is designed to hold the leak detector and an inspection camera; it is capable of rotation along two axes and has a linkage system which permits motion normal to the vacuum vessel wall. All systems except the dexterous slave arms are operable in a vacuum.

The JPL/KSC telerobotic inspection demonstration

An ASEA IRB90 robotic manipulator with attached inspection cameras was moved through a Space Shuttle Payload Assist Module (PAM) Cradle under computer control. The Operator and Operator Control Station, including graphics simulation, gross-motion spatial planning, and machine vision processing, were located at the Jet Propulsion Laboratory (JPL) in California. The Safety and Support personnel, PAM Cradle, IRB90, and image acquisition system, were stationed at the Kennedy Space Center (KSC) in Florida. Images captured at KSC were used both for processing by a machine vision system at JPL, and for inspection by the JPL Operator. The system found collision-free paths through the PAM Cradle, demonstrated accurate knowledge of the locations of obstacles and of objects of interest, and operated with a communication delay of two seconds. Safe operation of the IRB90 near Shuttle flight hardware was obtained through the use of both a gross-motion spatial planner developed at JPL using artificial intelligence techniques, and infrared beams and pressure sensitive strips mounted to the critical surfaces of the flight hardware at KSC. The Demonstration showed that ground/remote telerobotics is effective for real tasks, safe for personnel and hardware, and highly productive and reliable for Shuttle payload operations and Space Station external operations.

The TFTR maintenance manipulator

Abstract TFTR plans to begin D—T experiments in mid 1990. The D—T experimental program will produce approximately one hundred shots, with a neutron generation rate of 10 19 neutrons per shot. This will result in high levels of activation in TFTR, especially in the vacuum vessel. The primary purpose of the Maintenance Manipulator is to provide a means of remotely performing certain defined maintenance and inspection tasks inside the vacuum torus so as to minimize personnel exposure to radiation. The manipulator consists of a six-link folding boom connected to a fixed boom on a movable carriage. The entire manipulator is housed in a vacuum antechamber connected to the vacuum torus, through a port formerly used for a vacuum pumping duct. The configuration extends 180° in either direction to provide complete coverage of the torus. The four 3500 1/s turbopumps which were formerly used in the pumping duct will be mounted on the antechamber. The manipulator will utilize two end effectors. The first, called a General Inspection Arm (GIA) provides a moveable platform to an inspection camera and an in-vacuum leak detector. The second is a bilateral, force-reflecting pair of slave arms which utilize specially developed tools to perform several maintenance functions. All components except the slave arms are capable of operating in TFTR's vacuum environment and during 150°C bakeout of the torus.

Colour inspection camera designed for ROV use

Colour inspection camera designed for ROV use

Automatic control of gas pressure in a vacuum system: J Lucas et al, Vacuum, 32 (5), 1982, 2572̄263

TFTR plans to begin D—T experiments in mid 1990. The D—T experimental program will produce approximately one hundred shots, with a neutron generation rate of 1019 neutrons per shot. This will result in high levels of activation in TFTR, especially in the vacuum vessel. The primary purpose of the Maintenance Manipulator is to provide a means of remotely performing certain defined maintenance and inspection tasks inside the vacuum torus so as to minimize personnel exposure to radiation.The manipulator consists of a six-link folding boom connected to a fixed boom on a movable carriage. The entire manipulator is housed in a vacuum antechamber connected to the vacuum torus, through a port formerly used for a vacuum pumping duct. The configuration extends 180° in either direction to provide complete coverage of the torus. The four 3500 1/s turbopumps which were formerly used in the pumping duct will be mounted on the antechamber. The manipulator will utilize two end effectors. The first, called a General Inspection Arm (GIA) provides a moveable platform to an inspection camera and an in-vacuum leak detector. The second is a bilateral, force-reflecting pair of slave arms which utilize specially developed tools to perform several maintenance functions. All components except the slave arms are capable of operating in TFTR's vacuum environment and during 150°C bakeout of the torus.

Optical Design for Underwater Television Viewing Systems

The design of underwater television viewing systems is dictated to a large extent by the optical properties of the water and by the mechanical and dynamic constraints imposed on the sensor package by the application. The system design is usually also limited in lens selection to available commercial lenses. When the system designer includes the lens design as an integral part of the viewing system development, significant improvements in system performance can be achieved. This paper describes three lens designs which have been produced for three different underwater remote viewing applications: a remote controlled underwater inspection vehicle for offshore operations; a miniature underwater camera for internal inspection of water cooled nuclear reactors; and an underwater camera for submersibles, search systems, and work vehicle application. A unique feature of these lenses is the ability to orient the line of sight by rotatio of the optics rather than the camera. The added complexity of the optics in each case is more than offset by resulting advantages in the overall viewing system performance. The paper emphasizes the necessity for a system approach. which coordinates the design of the optics, sensor and illumination with other elements of the system to achieve optimum performance.