WO2000016033A1

WO2000016033A1 - Determining spatial relationship between two surfaces, closing spool meters

Info

Publication number: WO2000016033A1
Application number: PCT/GB1999/002902
Authority: WO
Inventors: William George Jackson; Sidney Campbell
Original assignee: ORCAM ENGINEERING Ltd
Current assignee: ORCAM ENGINEERING Ltd
Priority date: 1998-09-16
Filing date: 1999-09-16
Publication date: 2000-03-23
Anticipated expiration: 2001-03-16
Also published as: AU5871599A; GB9820080D0; GB2357581B; GB0106225D0; GB2357581A

Abstract

Apparatus and method for measuring position and orientation of a first and second surface (1a, 2a, 1d, 2d, 1e, 2e, 57b, 59b) with respect to each other for facilitating the construction of a closing spool to be fitted between two pipe end sections. The apparatus (3a, 3d, 3e, 50b) comprises means for defining at least one common axis (6a, 6d-1, 51b) between the surfaces and means for measuring the orientation of each surface with respect to the at least one common axis. The means for defining the common axis includes at least one linear measurement device in the form of a telescopic measuring rod, a linear transducer (20a, 120a, b, c, 20d-1) and a tensionable connector (63b, 5c). A clinometer/inclinometer is used to make an angle of slope measurement. The means for measuring the orientation of each surface with respect to the common axis determines the angle between the two via an angular transducer (17a, 19a, 117a, b, c, d). In a further embodiment the angle is determined from partially filled spheres (60b, 62b) on which latitude and longitude readings (74b) are marked on and read from. The entire apparatus can be preset from a reference calibration unit (40) to provide reference data for comparison to actual data recorded between two surfaces.

Description

DETERMINING SPATIAL RELATIONSHIP BETWEEN TWO SURFACES, CLOSING SPOOL METERS

The present invention relates to a measuring device, and in particular, though not exclusively, to a device for measuring the position and orientation of at least two surfaces with respect to each other . In many applications there is a requirement to know the relative position and orientation of objects with respect to each other. A typical example would be the position and orientation of two pipe end sections between which a custom manufactured closing spool requires to be fitted. ^• The dimensions of the closing spool relate directly to the position and orientation of respective flanges on the ends of the pipe sections.

The prior art describes a measurement system based on a theodolite. In that system the position and orientation of each of the flange surfaces is measured as a set of horizontal and vertical angles with respect to a single point, origin or horizon at some distance from the flange surfaces. The need for a reference point or horizon limits the use of these systems. Alternatively closing spools can be manufactured by trial and error with no relative measurements recorded. This is a time consuming process which requires a highly skilled individual.

An object of at least one aspect of the present invention is to obviate or mitigate one or more of the aforementioned disadvantages in the prior art.

A further object of at least one aspect of the present invention is to facilitate bespoke fabrication of a spool piece to close a section between two pipe ends. These and other objects are achieved by providing a measuring device which does not necessarily require a reference point, origin or horizon at some distance from the surfaces.

According to a first aspect of the present invention there is provided apparatus for measuring position and orientation of two surfaces with respect to each other comprising means for defining at least one common axis between the surfaces and means for measuring the orientation of each surface with respect to the common axis.

In one embodiment the surfaces are flanges located at ends of respective first and second pipes.

In another embodiment the surfaces are open ends of respective first and second pipes. Advantageously the first and second pipe ends may have respective first and second reference surfaces attached thereto .

Each reference surfaces may be at a fixed orientation with respect to the respective first or second surfaces. In the one embodiment the reference surface is a matching flange piece. The matching flange piece may include means for attaching one or more measurement devices.

In the other embodiment the reference surface is an end cap . The means for defining the at least one common axis may comprise axis defining apparatus positioned between at least one first common axis locating point provided on the first surface and at least one second common axis locating point provided on the second surface. The first and second common axis locating points are paired for each at least one common axis .

Preferably there is one means for defining one common axis .

Preferably the first and second common axis locating points are provided substantially centrally at the end of the respective first or second pipe.

Advantageously the axis defining apparatus includes at least one linear measurement device.

Advantageously the at least one linear measurement device provides a visible and/or electronic indication/readout of a measured length.

The at least one linear measurement device may be a telescopic measuring rod.

In a preferred embodiment the at least one linear measurement device is a linear transducer.

In a alternative embodiment the at least one linear measurement device is a graduated tensionable connection comprising a cable and tensionable winder.

In a further embodiment the at least one linear measurement device is three linear transducers. The three linear transducers may include ball joints at either end of the respective transducer. The three linear transducers may be arranged to be at or near the apexes of an equilateral triangle defined on the first and second reference surfaces. In a still further embodiment the at least one linear measurement device is six linear transducers. The six linear transducers may be arranged such that pairs of linear transducers are at or near the apexes of a first equilateral triangle on the first reference surface and neighbouring pairs of linear transducers are at or near the apexes of a second equilateral triangle on the second reference surface.

The axis defining apparatus may include an angle or slope measurement device.

In the preferred embodiment the angle of slope measurement device is an clinometer/inclinometer.

Advantageously the angle of slope measurement device provides a visible and/or electronic indication/readout of a measured slope or gradient.

The means for measuring the orientation of each surface with respect to the at least one common axes may comprise one or more means for determining an angle between each common axis and one or more first axes provided at a fixed orientation with respect to the first surface and one or more second axes, provided at a fixed orientation with respect to the second surface. Preferably there are provided two first and two second axes .

Advantageously the first axes lie on the first surface. Advantageously the second axes lie on the second surface.

The two first axes may be substantially perpendicular to each other.

Similarly, the two second axes may be substantially perpendicular to each other. Advantageously, the two first axes intersect each other at the first common axis locating point on the first surface. Advantageously also, the two second axis intersect each other at the second common axis locating point on the second surface . In the preferred embodiment the two first/second axes are defined by a pair of crossing lines constructed on the first/second surface relative to four holes drilled equidistantly upon the first/second flange.

In the alternative embodiment the two first/second axes are defined on a first/second circular surface provided by a surface of a first/second liquid in a partially filled first/second sphere.

In the further embodiment the first/second axes lie on the equilateral triangle on the first/second reference surface.

In the still further embodiment of the first/second axes lie on the first/second equilateral triangle on the first/second reference surface.

The means for determining the angle between the at least one common axis and the one or more first/second axes may comprise one or more angle measuring apparatus.

Advantageously the one or more angle measuring apparatus provides a visible and/or electronic indication/readout of a measured .angle - preferably measured in degrees. In the preferred embodiment the angle measuring apparatus is an angular transducer. The angular transducer may be mounted on the linear transducer. Alternatively the angular transducer may be integral with the linear transducer. Alternatively the angle measuring apparatus may be a

"Donut" (annular) type angular transducer. The "Donut" type angular transducer may be mounted around a shaft of the linear transducer, fixed on the vertical plane to the linear transducer or fixed on the rotary plane to the shaft of the linear transducer.

The angular transducer may include a third axis of movement. The third axis of movement may be rotary movement.

Alternatively the third axis of movement may be via the first/second reference surface. In the alternative embodiment the angle measuring apparatus is the partially filled sphere provided with latitude and longitude markings.

Each first/second sphere is advantageously at least partly transparent and/or translucent, so as to facilitate measurement readings.

Further in the alternative embodiment the end cap may be provided with angular markings.

In the further embodiment and the still further embodiment the means for determining the angle between the at least one common axis and the one or more first/second axis may comprise means for mathematically deriving the angle (s) from measurements made by the linear transducers and the length of the sides of the equilateral triangle.

According to a second aspect of the present invention there is provided a method for measuring position and orientation of first and second surfaces with respect to each comprising the steps of :

(a) providing apparatus for measuring position and orientation of the two surfaces with respect to each other comprising means for defining at least one common axis between the surfaces and means for measuring the orientation of each surface with respect to the at least one common axis;

(b) locating the apparatus relative the two surfaces;

(c) measuring the position and orientation of the first and second surfaces with respect to one another with reference to the at least one common axis.

Step (b) may include positioning axis defining apparatus between a first common axis locating points on the first surface and a second common axis locating points on the second surface.

Step (c) may include recording a distance between the first common axis locating points and the second common axis locating points along the at least one common axis using at least one linear measurement device comprising part of the apparatus.

Step (c) may include recording an angle of slope of the at least one common axis from a horizontal using an angle of slope measurement device.

Step (b) may include locating angle measuring apparatus between the at least one common axis and respective first and second axes defined with respect to the first and second surfaces .

Step (c) may include recording an angle between the at least one common axis and each of the first/second axes on the respective first/second surfaces from the angle measuring apparatus .

According to a third aspect of the present invention there is provided a reference calibration unit which, in use, presets an apparatus for measuring position and orientation of two surfaces with respect to each other.

The reference calibration unit may comprise means for presetting at least one linear measurement device and/or means for presetting an angle of slope measurement device and/or means for presetting one or more angle measuring apparatus. The reference calibration unit may attach onto and/or around the position and orientation measuring apparatus.

Advantageously the means for presetting the at least one linear measurement device comprises means for setting the at least one linear measurement device to record zero distance.

Alternatively the means for presetting the at least one linear measurement device may comprise means for recording a current (predetermined) linear measurement of the at least one linear measurement device. In a preferred embodiment the means for recording the current linear measurement of the at least one linear measurement device comprises a signal recording device.

In an alternative embodiment the means for setting the linear measuring device to record zero distance is a winding level attached to a tensionable winder.

Preferably the means for presetting the angle of slope measurement comprise horizontal positioning apparatus.

Alternatively the means for presetting the angle of slope measurement may comprise apparatus to record a current/preset angle of slope measurement.

Preferably the means for presetting the one or more angle measuring apparatus comprises means for setting the angle measuring apparatus to predetermined angle measurements . Advantageously the means for presetting the one or more angle measuring apparatus comprise means for recording a current/preset angle measurement.

In a preferred embodiment the means for recording a current angle measurement comprises a signal recording device.

According to a fourth aspect of the present invention there is provided a method for precalibrating an apparatus for measuring position and orientation of first and second the surfaces with respect to each other comprising the steps of: providing a reference calibration unit comprising means for presetting at least one linear measurement device, means for presetting an angle of slope measurement device and means for presetting one or more angle measurement apparatus; placing the reference calibration unit and the apparatus m operative relation; presetting the at least one linear measurement device; presetting the angle of slope measurement device; presetting the one or more angle measuring apparatus. Advantageously the preset data or reference calibration data is transferred to a signal recording unit.

According to a fifth aspect of the present invention there is provided a method of manufacturing a closing section apparatus to match the position and orientation of first and second surfaces with respect to each other including the steps of : providing a signal module comprising apparatus for measuring position and orientation of two surfaces with respect to each other; locating the apparatus between two surfaces; optionally attaching reference surfaces to the surfaces; positioning axis defining apparatus between at least one first common axis locating point on the first surface and at least one second common axis locating point on the second surface; recording a distance between the at least one first common axis locating point and the at least one second common axis locating point along at least one common axis from at least one linear measurement device; recording an angle of slope of the at least one common axis from an angle of slope measurement device; locating angle measuring apparatus between the at least one common axis and first and second axes on the first and second surfaces; recording the angle between the at least one common axis and each of the axes on the surfaces from the angle measuring apparatus. The signal module may include a signal recording unit for recording date.

The method may also include the steps of : storing data recorded m the signal recording unit; transferring data recorded to a simulation/response module; using the data to produce a fabrication template; cutting and machining the closing section apparatus to the fabrication template.

The apparatus for measuring position and orientation of two surfaces with respect to each other may be precalibrated m a reference calibration unit to a preset position.

Data relating to the present position may be stored m the signal recording unit. The preset data may also be transferred to the simulation module and compared to the measured data m use.

Advantageously the fabrication ISO (Isometric) is CAD (Computer Aided Design) produced. In one embodiment the closing section apparatus is a closing spool (pipe piece) .

In said embodiment the closing section apparatus may be QC (Quality Control) inspected after cutting and machining of the closing section apparatus. In said embodiment assembling the closing section apparatus may include welding out under controlled conditions .

In said embodiment the closing section apparatus may be subjected to NDT ( Non Destructive Testing ) and piping specification requirements and dimensionally checked to required tolerances.

In said embodiment a surface coating may be applied and inspected on the closing section apparatus.

In said preferred embodiment the closing section apparatus may be checked for alignment accuracy. According to a sixth aspect of the present invention there is provided a measuring device comprising a pair of at least partly transparent/translucent partially liquid filled spheres each provided with latitude and longitude markings and means for connection of a tensionable connection therebetween, a pair of partially cylindrical flanged end caps each having angular markings around the circumference, m use, the device measuring between two open pipe ends by inserting the end caps in the open pipe ends, arranging the spheres in said end caps and tensionmg the connection therebetween and determining dimensions between the two open ends of pipe from the relative positions of the spheres and end caps.

The dimensions so determined may be employed m fabricating a custom made pipe piece (spool) to join the pipe ends together.

Preferably the spheres are made of plastics material. Preferably also the tensionable connection comprise a cable and tensionable winder. Preferably also the end caps are marked with centralising circles.

These and other aspects of the present invention will become apparent from the following description of various embodiments of the present invention which are given by way of example only with reference to the accompanying drawings, in which :

Fig. 1 is a schematic diagram of apparatus for measuring position and orientation of two surfaces with respect to each other located between two surfaces m accordance with a first embodiment of the present invention;

Fig. 2 is a schematic diagram of a reference calibration unit containing the measuring apparatus of Fig. 1;

Fig. 3 is a linear transducer comprising part of the measuring apparatus of Fig. 1; Fig. 4 is an angular transducer comprising part of the measuring apparatus of Fig. 1;

Figure 5 shows alternative angular transducer arrangements (a) friction drive, (b) donut friction drive and (c) third axis of movement, for use with the linear transducer of Figure 1;

Figs. 6A-H are a series of schematic representations showing the steps involved m a method using the apparatus of Fig. 1;

Figure 7 is a schematic part section of Figure 1 showing an integrated visual display for use with the present invention;

Figure 8 is a schematic diagram of (a) exploded view and

(b) side view of apparatus for measuring position and orientation of two surfaces with respect to each other located between two surfaces in accordance with a second embodiment of the present invention;

Figure 9 is a schematic diagram of apparatus for measuring position and orientation of two surfaces with respect to each other located between two surfaces m accordance with a third embodiment of the present invention.

Fig. 10 is a schematic diagram of an apparatus for measuring position and orientation of two surfaces with respect to each other located between two surfaces in accordance with a fourth embodiment of the present invention; Fig. 11 is a side view of a pair of transparent spheres of a measuring device according to a fifth embodiment of the present invention;

Fig. 12 is a connecting wire of the measuring device of Fig. 11; Fig. 13 is a front view of an end cap of the measuring device of Fig. 11, and

Fig. 14 is a side view of the end cap of Fig. 13. Referring initially to Fig. 1 there is illustrated apparatus for measuring the orientation and position of two surfaces with regard to each other, generally designated 3a, according to a first embodiment of the present invention. The apparatus 3a is adapted to locate between two surfaces. In particular in this embodiment the apparatus 3a is adapted to locate between two open pipe ends, 5a and 7a, which terminate in flanges 9a and 11a.

The apparatus 3a comprises means for defining a common axis between the surfaces and means for measuring the orientation of each surface with respect to the common axis, which will be described in greater detail hereinafter. Apparatus 3a is located between two surfaces represented by a first flange 9a and a second flange 11a. Attached to first flange 9a is a matching first flange 13a and correspondingly second flange 11a has a second matching flange 15a, providing a first reference surface la and a second reference surface 2a, respectively.

A common axis 6a is defined between a first common axis locating point 12a centrally located on the first reference surface la and a second common axis locating point 14a centrally located on the second reference surface 2a. Located on apparatus 3a, along the common axis βa is a linear transducer 20a and a clinometer 22a. Recorded data from the linear transducer 20a and the clinometer 22a provide a measurement of the length of the common axis 6a and the angle of slope of the common axis 6a, describing the position of the reference surfaces la and 2a with respect to each other .

At each end of the common axis 6a there are located angular transducers 17a and 19a. The angular transducers 17a and 19a are located on the reference surfaces la and 2a and orientated such that their axis lie on the axes 8a and 10a defined by the lines AA and BB, and correspondingly, A'A' and B'B'. The axes 8a and 10a intersect at the common axis locating points 12a and 14a and lie on the reference surfaces la and 2a. . The axes are positioned relative to four holes 24a and 26a drilled equidistantly around the matching flanges 13 a and 15a .

The angular transducers 17a and 19a have shafts 23a and

25a which are attached to the apparatus 3a along the common axis 6a. The angles measured on the angular transducers 17a and 19a represent the orientation of each of the reference surfaces la and 2a with respect to the common axis 6a.

Referring now to Fig. 3 there is illustrated a linear transducer 20a for use in the measuring apparatus 13a. The linear transducer 20a comprises a resistive material chemically bended to a flat surface of printed circuit board material. There is also a conductive wiper W positioned at its centre of axis, capable of contacting the resistive plate across its surface, but free to move linearly along its path from A to B. If, for example, the resistance was 1000 Ohms, and a potential of 5 Volts d.c. was placed at 'A' and 0 volts d.c. was placed at 'B', then 'W should read 0 Volts d.c. when at end B and +5 Volts at end A, while linearly reflecting a voltage in proportion to its distance from end B as it is moved.

If end 'B' is mechanically fixed at a reference point, while 'W is connected to a moving point, the voltage measured at with reference to B will be representative of the actual distance W has moved from B. For example, if the resistive material is 500mm long, then 5 Volts = 'W is 500mm from 'B', similarly 0.1 Volts means 'W is 10mm from end 'B' etc. The accuracy of data is then down to the resolution of the measuring device.

This voltage can then be read by a computer using analogue to digital conversion techniques and stored for post processing .

Referring now to Fig. 4 there is illustrated an angular transducer 17a, 19a for use in the measuring apparatus 3a. The angular transducer 17a, 19a comprises a resistive material chemically bonded to a flat surface of printed circuit board material. There is also a conductive wiper W positioned at its centre of axis, capable of contacting the resistive plate across its surface, but free to move angularly +/-45 degrees from centre. If, for example, resistance was 1000 Ohms, and a potential of +4.5 Volts d.c. was placed at 'A' and -4.5 Volts d.c. was placed at 'B', then 'W should read 0 Volts d.c. when in the centre position.

If this is repeated for each angular movement we then have a voltage representation of angular movement for each axis, where if 4.5 Volts = 45 degrees movement then 0.1 Volt = 1 degree of movement etc. The accuracy of data is then down to the resolution of the measuring device. The polarity of the voltage indicates if it is plus or minus angle.

These voltages can then be read by a computer using analogue to digital conversion techniques and stored for post processing .

Reference is now made to Figure 5 of the drawings which depicts alternative angular transducer arrangements for use with the linear transducer of Figure 1. Figure 5(a) illustrates angular transducer 117a mounted "piggy-back" on linear transducer 120a. In this arrangement the angular transducer 117a does not require mounting to any flanges or base plates attached to either of the two surfaces from which measurements are required. The angular transducer 117a is friction driven as its movement and hence, measurement, is dependent on the friction drive of the wheel 40 on the shaft 41 of the linear transducer 120a. Figure 5(b) illustrates a further alternative arrangement. Linear transducer 120b comprises a linear transducer shaft 42 with a 'D' shape 44 or "keyway". A "Donut" shaped annular angular transducer 117b is then mounted either around the shaft 42 of the linear transducer .120b, fixed on the vertical plane to the linear transducer 120b or fixed on the rotary plane to the shaft 42 of the linear transducer 120b. The "donut" shaped angular transducer 117b is also friction driven from the shaft 42 of the linear transducer 120b. Figure 5(c) illustrates an arrangement whereby angular transducers 117c, 117d are mounted at either end of a linear transducer 120c. Angular transducers 117c, 117d have three axis of movement on which to make angular measurements. The three axis are left and right, 48a, 48b, up and own 49a, 49b and clockwise and anticlockwise 46a, 46b. Clockwise and anti-clockwise can be obtained from either direct rotary movement with respect to the shaft of the linear transducer 120c or with respect to a baseplate 47 onto which the angular transducer 117d and/or the linear transducer 120c is attached.

Reference is now made to Fig. 2 which illustrates a reference calibration unit, generally designated 40a, according to an embodiment of the present invention. The reference calibration unit is adapted to accept apparatus 3a for measuring posit±on and orientation of two surfaces with respect to each other. In particular, in this embodiment the reference calibration unit is adapted to receive electronic signals from the apparatus contained within.

The reference calibration unit 40a comprises reference surfaces 38a and 39a into which the first angular transducer

17a and the second angular transducer 19a are attached. The reference surfaces 38a and 39a are arranged to be perpendicular to the common axis 6a of the apparatus 3a. Each measurement device 20a, 17a, 19a on the apparatus 3a has a corresponding electronic signal line (30-36) to record and send data from a signal recording unit 37a. Lines 30,31,35 and 36 represent the lines for angles of measurement between the common axis 6a and the axes 8a and 10a, acquired from the angular transducers 17a and 19a. Line 32 records the linear distance of the common axis 6a from the linear transducer 20a. Lines 33 and 34 provide data on the pitch tilt and yaw to monitor the angle of slope measurement from the clinometer 22a. Signal module 37a can process the data ready for transmission to a manufacturing unit. The lines 30 - 36 are also shown on Figure 1 as lines 30a - 36a.

Referring now to Figs. 6A-H there are shown a series of schematic representations illustrating the steps involved in using the measuring apparatus 3a in a method of measuring the position and orientation of ends of two pipes and fabricating a spool piece for joining the ends.

There are provided two measurement apparatus 3a - a signal module and a simulation module.

The method comprises the following steps :

1. the signal module is positioned at the template location, Fig. 6A;

2. the simulation module m its preset position, F g. 6B, is at a fabrication unit;

3. the reading produced from the signal module is relayed to the simulation module;

4. the simulation module reproduces the signal modules position at its template location, Fig. 6C; 5. from the readings produced by the signal module a fabrication ISO is CAD produced with exact dimension material required to fabricate the precision spool, Fig. 6D;

6. the material is cut and machined to finished size and QC inspected;

7. the spool is assembled to the simulation module, Fig. 6E, and welded out under controlled conditions, Fig. 6F;

8. the finished spool is then subjected to N.D.T. and piping specification requirements and dimensionally checked to the required tolerances, Fig. 6G . Surface coating is applied and inspected;

9. the spool is coated for shipment to template location; 10. the spool is elected for shipment to the template location and checked for alignment accuracy, Fig. 6H .

The joints are then made by controlled bolt tensioning and monitored for line deflection, Fig. 61.

Illustrated m Figure 7 is an additional feature which may be incorporated into an embodiment of the present invention. Part of the apparatus 3a' is shown located against one open pipe end 5a', terminating m flange 9a'.

Attached to flange 9a' is a matching first flange 13a' to provide a first reference surface la'. The attachments to the first flange 13a' are as described for Figure 1 with the like parts being given the same alpha-numeric nomenclature but suffixed "'". in this arrangement signal lines 30a-36b shown m Figure 1 are replaced by internal connections to a signal module within the flange 13a' which displays values for the measurements of angle, slope and length on visual displays 40, 41. The number and position of the displays can be varied and may be located on either the first or the second flanges or both. This provides a compact arrangement of the first embodiment of the present invention, however it is applicable to all embodiments of the present invention.

Reference is now made to Figure 8 of the drawings which is illustrated an (a) exploded view and (b) side view of apparatus for measuring the orientation and position of two surfaces with respect to each other, generally designated 3d, according to a second embodiment of the present invention. The apparatus 3d is adapted to locate between two surfaces. In particular in this embodiment the apparatus 3d is adapted to locate between two open pipe ends, 5d and 7d, which terminate in flanges 9d and lid. The apparatus 3d comprises means for defining three common axis between the surfaces and means for measuring the orientation of each surface with respect to the common axes, which will be described m greater detail hereinafter.

Apparatus 3d is located between two surfaces represented by first flange 9d and a second flange lid. Attached to first flange 9d is a matching first flange 13d and corresponding second flange lid has a second matching flange 15d, providing a first reference surface Id and a second reference surface 2d, respectively. The matching flanges 13d, 15d can be considered as the end pieces of the measuring instrument .

Three common axis 6d, 6e, 6f are defined between first common axis locating points 12d, 12e, 12f located at the apexes of an equilateral triangle on the first reference surface Id and the second common axis locating points 14d, 14e, 14f located at the apexes of an equilateral triangle on the second reference 2d, respectively.

Located on apparatus 3d, along each common axis 6d, 6e, 6f is a linear transducer 20d, 20e, 20f. The linear transducers 20d, 20e, 20f have ball-joints mounted on each end of the transducers 20d, 20e, 20f so that linear transducers can more easily to be mounted on the surfaces Id, 2d. The linear transducers are connected at 120 degrees to each other. In use, the lengths on each linear transducer 20d, 20e, 20f, recorded on a signal recording unit (unit and cables not shown for clarity) or to a unit and visual display on one or both flanges 13d, 15d as shown m Figure 7, are used along with the angular arrangement of the transducers 20d, 20e, 20f to provide by trigonometry, the orientation of each surface Id, 2d with respect to any of the common axis 6d, 6e, 6f. This arrangement dispenses with the need for angular transducers and clinometers providing a cheaper measuring device . Reference is now made to Figure 9 of the drawings m which is illustrated an apparatus for measuring the orientation and position of two surfaces with respect to each other, generally designated 3e, according to a third embodiment . of the present invention. The apparatus 3e is adapted to locate between two open pipe ends 5e, 7e, which terminate m flanges 9e and lie. In this embodiment six linear transducers 20g - 1 are located between the flanges 9e and lie to provide six common axis 6g - 1 between the two reference surfaces le, 2e. As illustrated in the second embodiment, the linear transducers 20g - 1 are arranged at the apexes of equilateral triangles. In the third embodiment the linear transducers 20g - 1 are arranged such that pairs of linear transducers 20g, h, 20ι, , 20k, 1, are at the apexes i.e. common axis locating points 12g, h, I, on the first reference surface le and neighbouring pairs of linear transducers 20g, i, 20j, 1, 20h, k are at the apexes of i.e. common axis locating points 14 g, h, l on the second reference surface 2e. The linear transducers 20g - 1 are connected at 120 degrees to each other. The mechanical model m this instance allows for calculation of the orientation of the surfaces le, 2e with reference to any common axis 6g - 1 without the need for two flanges at either end of the measuring instrument.

Reference is now made to Fig. 10 depicting a fourth embodiment of the present invention. There is illustrated apparatus for measuring orientation and position of two surfaces with respect to each other, generally designed 50, according to the fourth embodiment of the present invention. The apparatus 50b is adapted to locate between two end caps placed into pipe sections.

The apparatus 50b, comprises means for defining a common axis between the surfaces and means for measuring the orientation of each surface with respect to the common axis, which will be described m greater detail hereinafter. The apparatus 50b is located between two end caps, 52b and 54b, positioned m the ends of open pipe sections 56b and 58b. The end caps 52b and 54b have an angular graticule 55b marked on surfaces perpendicular to the pipe section 56b and 58b. These surfaces are reference surfaces 57b and 59b. Into each end cap 52b and 54b is placed a partially filled sphere 60b and 62b. Each sphere is partially filled with a liquid, e.g. spirit 70b (shown only on one sphere 62b for clarity) . Each sphere 60b and 62b is rotated until cable 63b fixed to each sphere 60b and 62b at points 67b and 69b, respectively, provides the shortest distance between the spheres 60b and 62b. The cable 63b is adjusted via a tensionable winder 65b which records the distance between the spheres 60b and 62b and consequently relates directly to the length of a common axis 51b between the reference surfaces 57b and 59b.

Inscribed into each of the spheres 60b and 62b is latitude and longitude markings 74b relative to pole positions at the points 67b and 69b. For each sphere 60b and 62 the latitude and longitude is recorded for the circle between the sphere 60b and 62b and the edge of the end cap 52b and 54b, respectively. The latitude and longitude circle is read off from the horizontal 72b created as the surface of the spirit 70b m the partially filled spheres 60b and 62b. The latitude and longitude position is recorded at an angular graticule 55b marking relative to a bolt hole wftich would be positioned on the manufactured flange of the closing spool. These six recordings provide measurements for the diameter of the closing spool and the bending radius of each end to match the reference surfaces 57b and 59b. They define the orientation of the reference surfaces 57b and 59b with respect to the common axis 51b.

In use the recordings from the preferred or alternative embodiments are used to manufacture a closing spool. The recordings are transferred to a CAD system from which a fabrication 150b template is designed. Material is cut and machined to the template and the closing spool is assembled including welding flanges to match the reference surfaces.

The closing spool is subjected to NDT and piping specification requirements and dimensionally checked to required tolerances. The closing spool is surface coated and finally checked for alignment accuracy.

Referring now to Figs. 11 to 14 there is illustrated a measuring device according to a fifth embodiment of the present invention comprising a pair of hollow transparent spheres lc and 2c each provided with a rigid female cable connector 3c and 4c.

A connecting wire 5c comprising a winding cable drum 6c for tensioning or slackening the wire is also provided. The wire 5c has at each end male cable connectors 7c. A pair of flanged end caps 8c are also provided.

The spheres lc and 2c are of plastics material 1/16" thick approximately and are 4V2" in diameter. The spheres have latitude and longitude markings and are half filled with spirit at the north pole of one sphere and the south pole of the other sphere.

The female cable connectors 3c and 4 c are 1/16" type to correspond to the male cable connectors 7c on the wire 5c.

The end caps 8c are of rigid plastics material, have a

4V2" diameter bore, a 2/4" depth and a 10" outside diameter flange 9c. The flange 9c has 360" markings 10c scribed on it together with bull's eye circles 11.

The measuring device is used to lift the template of a pipe section between two open ends of pipe with or without flanges. The particular device described is suitable for pipes of 5" diameter bore.

In use the end caps 8c are placed into each open pipe end and centralised to the bull's eye lie. The spheres lc and 2c are positioned in each end cap 8c and connected with the connecting wire 5c. The wire 5c is tensioned using the cable drum 6c so that both spheres lc and 2c are directly opposed. The spheres lc and 2c are rotated to a common latitude and longitude position as read from the spirit levels. Both end caps 8c are rotated to a common longitude line and a. reading is taken off the circle where each pipe end bisects the spheres lc and 2c. A reading is then taken off the nearest bolt hole on both flanges in a clockwise direction viewed m a common direction to both flanges.

It is then possible to calculate the pipe dimensions necessary to accommodate the surroundings from the known PCD (Pitch Centre Diameter) and the given RAD (Radius) .

It will be appreciated that the principal advantage of the present invention is that it provides an accurate measurement of position and orientation of two surfaces without the need of a distant point or horizon for reference. It will be understood by the skilled person that the emoodi ents of the invention hereinbefore described are given by way of example only and are not meant to limit the scope thereof m any way.

For example, a signal receiving unit connected by signal cables is illustrated as is integrated electronics in one or more flanges to show a visual display of measurements made. Alternative display means may be used such as manual setting devices or the signals could be transmitted by a cordless medium to a separate recording device. In addition, for example, the embodiments describe a measurement system for pipe fabrication. However, the present invention could be utilised m heating and ventilation systems (H.V.A.C.), enhancing plant and process designs. In this way the present invention could find application m a range of industries including the oil and gas industries, petrochemical, nuclear, gas and coal electrical power generation and pharmaceutical producers.

Claims

1. Apparatus for measuring position and orientation of a first and a second surface with respect to each other comprising means for defining at least one common axis between surfaces and means for measuring the orientation of each surface with respect to the at least one common axis.

2. Apparatus according to claim 1 wherein the surfaces are flanges located at ends of respective first and second pipes.

3. Apparatus according to claim 1 wherein the surfaces are open ends of respective first and second pipes.

4. Apparatus according to claim 2 or claim 3 wherein the first and second pipe ends have respective first and second reference surfaces attached thereto.

5. Apparatus according to claim 4 wherein each reference surface is at a fixed orientation with respect to the respective first and second surface.

6. Apparatus according to claim 4 or claim 5 wherein the reference surfaces are matching flange pieces.

7. Apparatus according to claim 6 wherein the matching flange pieces include means for attaching one or more measurement devices .

8. Apparatus according to claim 4 to 5 wherein the reference surfaces are end caps .

9. Apparatus according to any preceding claim wherein the means for defining the at least one common axis comprises axis defining apparatus positioned between at least one first common axis locating point provided on the first surface and at least one second common axis locating point provided on the second surface.

10. Apparatus according to any preceding claim wherein there is one means for defining one common axis.

11. Apparatus according to claim 9 or claim 10 wherein the first and second common axis locating points are provided substantially centrally at the end of the respective first or second pipe.

12. Apparatus according to any one of claims 9 to 11 wherein the axis defining apparatus includes at least one linear measurement device.

13. Apparatus according to claim 12 wherein the at least one linear measurement device provides a visible and/or electronic indication/readout of a measured length.

14. Apparatus according to claim 12 or claim 13 wherein the at least one linear measurement device is a telescopic measuring rod.

15. Apparatus according to claim 12 or claim 13 wherein the at least one linear measurement device is a linear transducer.

16. Apparatus according to claim 12 or claim 13 wherein the at least one linear measurement device is a graduated tensionable connection comprising a cable and a tensionable winder .

17. Apparatus according to claim 15 wherein the at least one measurement device is three linear transducers.

18. Apparatus according to claim 15 or claim 17 wherein the linear transducer (ε) include ball joints as the means for attaching to the matching flange pieces.

19. Apparatus according to claim 17 or claim 18 wherein the three linear transducers are arranged at or near the apexes of triangles on the first and second reference surfaces.

20. Apparatus according to claim 15 wherein the at least one measurement device is six linear transducers.

21. Apparatus according to claim 20 wherein the six linear transducers are arranged such that three pairs of linear transducers are at or near the apexes of a first equilateral triangle on the first reference surface and neighbouring pairs of linear transducers are at or near the apexes of a second equilateral triangle on the second reference surface.

22. Apparatus according to any one of claims 9 to 21 wherein the axis defining apparatus includes an angle of slope measurement device .

23. Apparatus according to claim 22 wherein the angle of slope measurement device is a clinometer/inclinometer.

24. Apparatus according to claim 22 or claim 23 wherein the angle of slope measurement device provides a visible and/or electronic indication/readout of a measured slope or gradient.

25. Apparatus according to any preceding claim wherein the means for measuring the orientation of each surface with respect to the at least one common axis comprises one or more means for determining an angle between the at least one common axis and one or more first axes provided at a fixed orientation with respect to the first surface and one or more second axes provided at a fixed orientation with respect to the second surface.

26. Apparatus according to claim 25 wherein there are provided two first and two second axes.

27. Apparatus according to claim 25 or claim 26 wherein the first axes lie on the first surface.

28. Apparatus according to any one of claims 25 to 27 wherein the second axes lie on the second surface.

29. Apparatus according to any one of claims 26 to 28 wherein the first two axes are substantially perpendicular to each other.

30. Apparatus according to any one of claims 26 to 29 wherein the two second axes are substantially perpendicular to each other.

31. Apparatus according to any one of claims 26 to 30 wherein the two first axes intersect each other at the first common axis locating point on the first surface.

32. Apparatus according to any one of claims 26 to 31 wherein the two second axis intersect each other at the second common axis locating point on the second surface.

33. Apparatus according to any one of claims 26 to 32 wherein the first/second axes are defined by a pair of crossing lines constructed on the first/second surface relative to four holes drilled equidistantly upon the first/second flange.

34. Apparatus according to any one of claims 26 to 32 wherein the two first/second axes are defined on a first/second circular surface provided by a surface of a first/second liquid in a partially filled first/second sphere .

35. Apparatus according to claim 25 wherein the first/second axes lie on the triangle on the first/second reference surface .

36. Apparatus according to claim 25 wherein the first/second axes lie on the first/second equilateral triangle on the first/second reference surface.

37. Apparatus according to any one of claims 25 to 36 wherein the means for determining the angle between the at least one common axis and the one or more first/second axes comprises one or more angle measuring apparatus.

38. Apparatus according to claim 37 wherein the one or more angle measuring apparatus provides a visible and/or electronic indication/readout of a measured angle.

39. Apparatus according to claim 37 or claim 38 wherein the angle measuring apparatus is an angular transducer.

40. Apparatus according to claim 39 wherein the angular transducer is mounted on the linear transducer.

41. Apparatus according to claim 39 wherein the angular transducer is integral with the linear transducer.

42. Apparatus according to any of claims 39 to 41 wherein the angular transducer is a "do-nut" annular type transducer.

43. Apparatus according to any of claims 39 to 42 wherein the angular transducer has three axis of movement.

44. Apparatus according to claim 37 or claim 38 wherein the angle measuring apparatus is the partially filled sphere provided with latitude and longitude markings.

45. Apparatus according to claim 44 wherein each first/second sphere is at least partly transparent and/or translucent, so as to facilitate measurement readings.

46. Apparatus according to claim 44 or 45 wherein the end cap is provided with angular markings.

47. Apparatus according to claim 35 or claim 36 wherein the means for determining the angle between the at least one common axis and the one or more first/second axes comprises means for mathematically deriving the angle (s) from measurements made by the linear transducers and the lengths of the sides of the triangle (s) .

48. A method for measuring position and orientation of first and second surfaces with respect to each other comprising the steps of : ^'

(b) locating the apparatus relative the two surfaces;

49. A method according to claim 48 wherein step (b) includes positioning axis defining apparatus between a first common axis locating points on the first surface and a second common axis locating points on the second surface.

50. A method according to claim 48 wherein step (c) includes recording a distance between the first common axis locating points and the second common axis locating points along the at least one common axis using at least one linear measurement device comprising part of the apparatus.

51. A method according to any one of claims 48 to 50 wherein step (c) includes recording an angle of slope of the at least one common axis from a horizontal using an angle of slope measurement device.

52. A method according to any one of claims 48 to 51 wherein step (b) includes locating angle measuring apparatus between the at least one common axis and respective first and second axes defined with respect to the first and second surfaces.

53. A method according to claim 52 wherein step (c) includes recording an angle between the at least one common axis and each of the first/second axes on the respective first/second surfaces from the angle measuring apparatus .

54. A reference calibration unit which, in use, presets an apparatus for measuring position and orientation of two surfaces with respect to each other, the reference calibration unit comprising means for presetting at least one linear measurement device and/or means for presetting an angle of slope measurement device and/or means for presetting one or more angle measuring apparatus.

55. A reference calibration unit according to claim 54 wherein the reference calibration unit attaches onto and/or around the position and orientation measuring apparatus.

56. A reference calibration unit according to claim 54 or claim 55 wherein the means for presetting the at least one linear measurement device comprises means for setting the at least one linear measurement device to record zero distance.

57. A reference calibration unit according to claim 54 or claim 55 wherein the means for presetting the at least one linear measurement device comprises means for recording at least one current (predetermined) linear measurement of the at least one linear measurement device.

58. A reference calibration unit according to claim 57 wherein the means for recording the at least one current linear measurement of the at least one linear mesurement device comprises a signal recording device.

59. A reference calibration unit according to any one of claims 56 to 58 wherein the means for setting the at least one linear measuring device to record zero distance is a winding level attached to a tensionable winder.

60. A reference calibration unit according to any one of claims 54 to 59 wherein the means for presetting the angle of slope measurement comprises horizontal positioning apparatus .

61. A reference calibration unit according to any one of claims 54 to 59 wherein the means for presetting the angle of slope measurement comprises apparatus to record a current/preset angle of slope measurement.

62. A reference calibration unit according to any one of claims 54 to 61 wherein the means for presetting the one or more angle measuring apparatus comprises means for setting the angle measuring apparatus to predetermined angle measurements .

63. A reference calibration unit according to any one of claims 54 to 62 wherein the means for presetting the one or more angle measuring apparatus comprises means for recording a current/preset angle measurement.

64. A reference calibration unit according to claim 63 wherein the means for recording a current angle measurement comprises a signal recording device.

65. A method for precalibrating an apparatus for measuring position and orientation of first and second surfaces with respect to each other comprising the steps of: providing a reference calibration unit comprising means for presetting at least one linear measurement device, means for presetting an angle of slope measurement device and means for presetting one or more angle measurement apparatus; placing the reference calibration unit and the apparatus in operative relation; presetting the at least one linear measurement device; presetting the angle of slope measurement device; presetting the one or more angle measuring apparatus.

66. A method according to claim 65 wherein preset data or reference calibration data is transferred to a signal recording unit .

67. A method of manufacturing a closing section apparatus to match ^'the position and orientation of first and second surfaces with respect to each other including the steps of : providing a signal module comprising apparatus for measuring position and orientation of two surfaces with respect to each other; locating the apparatus between two surfaces; optionally attaching reference surfaces to the surfaces; positioning axis defining apparatus between at least one first common axis locating point on the first surface and at least one second common axis locating point on the second surface; recording a distance between the at least one first common axis locating point and the at least one second common axis locating point along the at least one common axis from at least one linear measurement device; recording an angle of slope of the at least one common axis from an angle of slope measurement device; locating angle measuring apparatus between the at least one common axis and first and second axes on the first and second surfaces; and recording the angle between the at least one common axis and each of the axes on the surfaces from the angle measuring apparatus .

68. A method according to claim 67 wherein the signal module includes a signal recording unit for recording data.

69. A method according to claim 67 or claim 68 wherein the method also includes the steps of: storing data recorded in the signal recording unit; transferring data recorded to a simulation module; using the data to produce a fabrication template; and cutting and machining the closing section apparatus to fabricate the template.

70. A method according to any one of claims 67 to 69 wherein the apparatus for measuring the position and orientation of two surfaces with respect to each other is precalibrated in a reference calibration unit to a preset position.

71. A method according to claim 70 wherein data relating to the preset position is stored in the signal recording unit.

72. A method according to claim 71 wherein preset data is also transferred to the response unit and compared to the measured data in use .

73. A method according to any one of claims 69 to 72 wherein the fabrication template is a fabrication ISO (Isometric) and is CAD (Computer Aided Design) produced.

74. A method according to any one of claims 67 to 73 wherein the closing section apparatus is a closing spool (pipe piece) .

75. A method according to any one of claims 67 to 74 wherein the closing section apparatus is QC (Quality Control) inspected after cutting and machining of the closing section apparatus .

76. A method according to any one of claims 67 to 75 wherein assembling of the closing section apparatus includes welding out under controlled conditions.

77. A method according to any one of claims 67 to 76 wherein the closing section apparatus is subjected to NDT (Non Destructive Testing) and piping specification requirements and dimensionally checked to required tolerances.

78. A method according to any one of claims 67 to 77 wherein a surface coating is applied and inspected on the closing section apparatus.

79. A method according to any one of claims 67 to 78 wherein the closing section apparatus is checked for alignment accuracy. '

80. A measuring device comprising a pair of at least partly transparent/translucent partially liquid filled spheres each provided with latitude and longitude markings and means for connection of a tensionable connection therebetween, a pair of partially cylindrical flanged end caps each having angular markings around the circumference, in use, the device measuring between two open pipe ends by inserting the end caps in the open pipe ends, arranging the spheres in said end caps and tenεioning the connection therebetween and determining dimensions between the two open ends of pipe from the relative positions of the spheres and the end caps.

81. A measuring device according to claim 80 wherein dimensions so determined are employed in fabricating a custom made pipe piece (spool) to join the pipe ends together.

82. A measuring device according to claim 80 or claim 81 wherein the spheres are made of plastics material.

83. A measuring device according to any one of claims 80 to 82 wherein the tensionable connection comprises a cable and tensionable winder.

84. A measuring device according to any one of claims 80 to 83 wherein the end caps are marked with centralising circles.

85. Apparatus for measuring position and orientation of a first and a second surface with respect to each other as described herein and illustrated in figures 1 to 5 or Figure 7 or Figure 8 or Figure 9 of figures 10 to 14.

86. A method for measuring position and orientation of first and second surfaces with respect to each other as described herein and illustrated in Figure 6.

87. A reference calibration unit as described herein and illustrated in Figure 2.

88. A method for precalibrating an apparatus for measuring position and orientation of first and second surfaces with respect to each other as described herein and illustrated in Figure 6.

89. A method of manufacturing a closing section apparatus to match the position and orientation of first and second surfaces with respect to each other as described herein and illustrated in figures 1 to 6 or figures 2, 6, and 7 or figures 2, 6, and 8 of figures 2, 6, and 9 or figures 2, 6, 10 to 14.