GB2342419A

GB2342419A - Pipe Inspection Device

Info

Publication number: GB2342419A
Application number: GB9821657A
Authority: GB
Inventors: Alan Keith Sefton; David James Cotton
Original assignee: Pearpoint Ltd
Current assignee: Pearpoint Ltd
Priority date: 1998-10-05
Filing date: 1998-10-05
Publication date: 2000-04-12
Anticipated expiration: 2018-10-05
Also published as: GB9821657D0; GB2342419B

Abstract

A pipe inspection device comprises a housing (5) within which are mounted cameras having respectively a forwarding-looking field of view through a forward window (7) and a sideways-looking camera having a field of view through a sideways-looking window (9). The cameras may be rotatable about a longitudinal axis of the housing whilst maintaining fields of view through the respective windows (7), (9).

Description

Pipe Inspection Device The present invention relates to a pipe inspection device particularly, although not exclusively, for use with a semi-rigid rod or tractor operated inspection systems.

Hitherto, pipeline inspection devices have generally comprised a chassis on which is mounted a camera having a forward-looking view and a separate light source. In some cases the device may be connected to one end of a semirigid rod which rod is pushed down a pipe to be inspected.

The rod carries electrical power to the device from a supply outside the pipe and at the same time image signals from the camera are carried by the rod to a monitor outside the pipe. A particular disadvantage of such a system is that the rod inevitably twists as it is pushed along the pipe thereby rotating the camera about its longitudinal or the roll axis so that the image displayed on the monitor is similarly rotated. As a result, it is often difficult for a viewer of an image displayed on the monitor to determine the orientation of the image unless a separate visual reference, such as a liquid present in the pipe, is visible.

As a result of the problem inherent in the above described system and in recognition of the fact that the viewer is often more interested in viewing the state of the inner surface of the pipe, rather than looking along the pipe, devices have been developed in which the camera is movable between a forward-looking view for use particularly when travelling along the pipe and a sideways-looking view to more closely inspect the inner surface of the pipe at desired locations. However, such devices also suffer from a number of disadvantages. Firstly, they have tended to be larger in order to accommodate the mechanism necessary to provide both views and thus cannot be used in smaller bore pipes. Secondly, the time taken to translate the camera between the two views places a restriction on the speed at which surveys can be undertaken.

Thus it is an object of the present invention to provide a pipe inspection device which overcomes the abovementioned disadvantages.

It is a further object of the present invention to provide a device which is more energy efficient and a still further object to provide a device which is more reliable and less vulnerable to damage.

According to the present invention, a pipe inspection device comprises a housing within which are mounted a pair of cameras having respectively forward-looking and sideways-looking fields of view.

In addition to the cameras, the housing may further include at least one illumination source which is compatible with their wavelength of operation.

Advantageously, the housing is provided with one or more transparent sections providing the above described fields of view. Thus, the sideways-looking field of view might be provided by a circumferentially extending section whilst a separate section provides a forward looking field of view. Alternatively, a single transparent nose section might provide both fields of view. In either case, the sideways-looking field of view may extend around the entire housing by providing means for rotating the camera about its pitch axis. Conveniently, the means may also provide for rotation of the camera providing the forward-looking field of view about its roll axis.

The above described device can be produced as a very compact package particularly as both focus and iris control for each camera may be shared. In addition, the fact that the cameras and their associated controls are completely enclosed within the device eliminates the need for expensive sealed rotating external parts. Furthermore by integrating high-intensity LEDs onto PCBs surrounding the camera lenses this provides sufficient illumination for the cameras without the need for an external source.

In order to aid in understanding the invention a specific embodiment thereof will now be described by way of example and with reference to the accompanying drawings, in which: Figure 1 is a side view of a pipe inspection device according to the invention; Figure 2 is a cross-sectional side view on the line II-II of Figure 1; and Figure 3 is a cross-sectional side view on the line III-III of Figure 1.

Referring to the Figures, there is shown a pipe inspection device 1 connected to a semi-rigid rod 3. The device 1 has a protective casing 5 in which is provided a pair of transparent windows 7,9 one of which 7 provides a forward-looking field of view for a camera 11 and its associated LED illumination array 13 and the other 9 providing a sideways-looking field of view about the entire circumference of the device 1 for a further camera 15 and its associated LED illumination array 17. The illumination arrays 13,17 are each carried on a PCB 19,21 which encircles the lens of its respective camera 11,15.

The cameras 11,15 are mounted within a rotatable member 23 suspended between bearings 25, 27 towards opposite ends of the casing 5. A single rotation motor 29 mounted within the casing 5 provides for rotation of the member 23 which brings about rotation not only of the forward-looking camera 11 about its roll axis but also rotation of the sideways-looking camera 15 about its pitch axis. Thus the motor 29 can compensate for rotation in the forward-looking view and also provide a sideways-looking view around the entire circumference of the casing 5. If required, an output signal from a sensor (not shown) can steady the image shown on a monitor (not shown) by driving the rotation motor 29 in response to changes in the attitude of the device 1. The member 23 further carries separate iris and focus control motors 30,31 each of which is linked to both cameras via gearing 33 in the case of the focus control and a system of cables and pulleys 35 for iris or depth of field control. The operation of the rotation, iris and focus motors 29,30,31 is all under software control such that their various settings or an"image state"are memorised on leaving a view such that the monitor display will revert to the previously stored"image state" associated with a view when returning to that view.

Furthermore, the selection of a particular view activates solely that camera and its associated illumination array thereby saving power.

In use, the device is introduced to a pipe (not shown) and moved along the length of the pipe by manipulating a semi-rigid rod which carries both power and control signals to the device and image signals from the cameras to the monitor. An operator controls the view obtained from the device with a keypad and joystick which provide the control signals to the device.

It will be appreciated by those skilled in the art that although the above describes an embodiment of the device suited for use with a semi-rigid rod system, the device of the invention is equally suited to being mounted on a tractor-type inspection apparatus which trails a cable rather than a semi-rigid rod.

Claims

CLAIMS 1. A pipe inspection device comprising a housing within which are mounted a pair of cameras having respectively forward-looking and sideways-looking fields of view.
2. A device according to Claim 1 wherein the housing further includes at least one illumination source which is compatible with the wavelength of operation of the cameras.
3. A device according to Claim 1 or 2, wherein the housing comprises one or more transparent sections corresponding to the fields of view of said cameras.
4. A device according to Claim 3 wherein the housing comprises a circumferentially extending transparent section corresponding to the field of view of the sideways-looking camera.
5. A device according to Claim 4 wherein a single transparent nose section of the housing provides fields of view for both cameras.
6. A device according to Claim 4 or 5 wherein the circumferentially extending section extends around the entire circumference of the housing, and means is provided for rotating the sideways-looking camera about its pitch axis.
7. A device according to Claim 6, wherein the means for rotating the sideways-rotating camera also provides for rotation of the camera providing the forwarding-looking field of view about its roll axis.
8. A device according to Claim 6 or 7 wherein a sensor responsive to changes in attitude of the device is arranged to drive the rotation means.
9. A device according to Claim 2 or any one of Claims 3 to 8 as appended thereto, wherein the said illumination source or sources each comprise an array of high intensity light emitting diodes integrated onto a printed circuit board surrounding a camera lens.
10. A pipe inspection device substantially as described herein with reference to the accompanying drawings.