CA1156828A - Device for the dynamic measurement of inclinations - Google Patents
Device for the dynamic measurement of inclinationsInfo
- Publication number
- CA1156828A CA1156828A CA000375258A CA375258A CA1156828A CA 1156828 A CA1156828 A CA 1156828A CA 000375258 A CA000375258 A CA 000375258A CA 375258 A CA375258 A CA 375258A CA 1156828 A CA1156828 A CA 1156828A
- Authority
- CA
- Canada
- Prior art keywords
- light
- detector means
- housing
- light spot
- predetermined point
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01C—MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
- G01C9/00—Measuring inclination, e.g. by clinometers, by levels
- G01C9/12—Measuring inclination, e.g. by clinometers, by levels by using a single pendulum plumb lines G01C15/10
- G01C9/14—Measuring inclination, e.g. by clinometers, by levels by using a single pendulum plumb lines G01C15/10 movable in more than one direction
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01C—MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
- G01C9/00—Measuring inclination, e.g. by clinometers, by levels
- G01C9/02—Details
- G01C9/06—Electric or photoelectric indication or reading means
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- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- General Physics & Mathematics (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Length Measuring Devices By Optical Means (AREA)
- Geophysics And Detection Of Objects (AREA)
- Lubrication Of Internal Combustion Engines (AREA)
- Investigating, Analyzing Materials By Fluorescence Or Luminescence (AREA)
- Spectrometry And Color Measurement (AREA)
Abstract
ABSTRACT
The invention relates to an inclinometer for dynamically measuring inclinations to the vertical. The inclinometer includes a resilient thread consisting of an optic fibre which is firmly held at one end thereof in a holder. The firmly held end of the fibre is arranged to co-act with a light source. The fibre is completely free of all load and its free end lies close to the surface of a detector means and transmits light in punctiform onto the surface of the detector.
The invention relates to an inclinometer for dynamically measuring inclinations to the vertical. The inclinometer includes a resilient thread consisting of an optic fibre which is firmly held at one end thereof in a holder. The firmly held end of the fibre is arranged to co-act with a light source. The fibre is completely free of all load and its free end lies close to the surface of a detector means and transmits light in punctiform onto the surface of the detector.
Description
~ device for the dynamic rneasurement of inclinations .. ... _ .
The present invention relates to a device for the dyn~mic measurement of inclinations relative to the verticalt comprising a resilient thre~d which is firmly held at one end in a holder and the other, free end of which is arranged to co-oct with a light source adapted to irradiate n light-sensitive detector means.
A device of this general kind can be constructed from the teachings of Swedish Patent Specification No 141 501 and the US P~tent Speci-ficr.tion No 3,324,564. The Swedish Specification 141 501 refers to n device having o flexible thread or rod whose free end is loaded with a weight which when the device is inclined causes the thread or rod to bend~ The bending stresses and strains occurring in the rod are de-tected by means of Q strain gauge. The U.S. Pater~t Specification No 3,324,564 relates to a device having a pendulum whose free end car-ries an incandescent lamp which is arranged to co-act with a light-sensitive detector in a manner to indicate the angle at whirh the pen-20 dulum is inclined to the vertical. Even though the rigid pendulum ofthe device nccording to the U.S. Patent Specification No 3 324 564 should be replaced with a flexible, loaded rod according to the Swedish Patent Specification No 141 501, it would still not be possible to provide an inclinometer which is sensitive and which reacts quickly, owing substantially to the relatively high mass of the part which indi-cates the angle of inclination.
Consequently it is a prime object of the invention to provide an in-clinometer of the kind set forth in the introduction which although comprising a combination of the devices disclosed in the two aforemen-tioned patent specifications is nevertheless very precise and reacts -~ - 2 -extremely rapidly, thereby enabling it to be used for indicating those settlements and subsidences which occur even with slight earth tremors. ~Iereinafter the inclinometer according to the invention is stated as being used mainly for measuriny -the inclination of a bore or drilled hole or the like.
A further object of the invention is to provide an inclinometer which will not only indicate any deviation from the vertical, but will also indicate the bend in a drilled hole or bore which is not straight.
According to the present invention, then, -there is provided a device for dynamically measuring inclinations from the vertical comprising a housing, a flexible optic fibre firmly held at one end thereof by a mount supported in the housing with the other end of the fibre being free to move in response to the inclination of the device, a light source located adjacent the firml~ held end for directing light through the fibre to the free end thereof, and light-sensitive detector means disposed proximal to -the free end such that light emerging from the free end creates a light spot thereon, wherein the detector means are responsive to the light spot to produce signals indicative of the position of the light spot relative to a predetermined point of reference on the detector means.
Embodiments of the present invention will now be described in greater detail and will be better understood when read in conjunction with the following drawings in which:
z~
Figure 1 is a simplified axial sectional view of an inclinometer according to the invention having a schematically illustrated inclination indicating means, Figure 2 illustrates a suitable, fundamental detector means for use in the inclinometer according to the invention, Figure 3 is a simplified view of an inclinometer according ko the invention for the simultaneous measurement of the curvature of a bore, Figures ~a, 4b and 4c illustrate the positions of the measuring ~0 points on the detector of the inclinometer when simultaneously measuring the inclination and curvature of a bore from a given line, and Figures 5a and 5b illustrate the inclination and the curvature of the device which gives rise to measuring point posi-tions illustrated in Figures 4a - 4c.
Fig. 1 is a simplified axial sectional view of a device according to the invention intended for determining deviations from the vertical. When the device of the illustrated embodiment is fully vertical, deviation from the vertical is zero.
The device illustrated in Figure 1 includes a housing 1, which in the shown embodiment is assumed to be cylindrical but which may have any cross-sectional configuration suit-able for the use to which the device is to be put. The housina 1 has an upper cap 2 provided with an opening 3 for a cable 4 having two electrical conductors 5 and 6 for supplying voltage to a light-emitting diode 7, or some other source of light radiation which produces infra-red, ultraviolet or visible light. Hereinafter it is assumed that the light source has the form of a light-emitting diode and that said diode is supplied with an alternating voltage having a frequency of, for example, 100Q H~. It will be understood, however, that any suitable frequency may be used and that the diode 7 may be supplied with a direct-current voltage. In the illustrated embodiment, the light-emit-ting diode 7 is mounted on the upper side of a plug 8, which form a holder for an optic fibre 9. The fibre 9 is firmly held at one end 10 thereof in the holder 8 while the remainder of the fibre is freely movable and is free of any load. The upper end 10 of the fibre ~ is arranged to co-act with the diode 7, and light from the diode will thus be transmitted to the free end 11 of the fibre 9. The free end 11 lies above a detector 12 and is located so close to the surface of the detector that a well defined, small spot of light is projected onto said surface.
The fundarnental principle of a suitable detector 12 is illustroted in Fioure 2. The detector 12 of the illustrated embodiment has the form of a known, so-called lateral photo detector which is constructed about a sauare plote comprisina a semi conductor material. The upper side of the plate is covered with a light-permeable gold 1ayer~ while the underside has a thin homogeneous layer of resistive materinl.
Arranged along the periphery of the resistive layer (not shown ), ad-jacent the edges of the plate, are two pairs of mutually opposite dis-charge electrodes 13,13 and 14,14. ~!hen a point 15 is illuminated, the light flow aives rise to a voltage/current source across the p-n-transition zone present in the doped plate. This voltage/current source is able to form a closed circuit vin srid gold layer and the resistive layer with the electrodes 13,13 and 14,14, and thus four part current-flows, one for each electrode, can be registered. The mog-nitude of these pnrt current-flows is dependent upon the distonce of the liaht spot 15 from the oriain 16 of the coordinates in the incor-porated XY-system The four current-flows tnken out through the elec--trodes 13,13 and 14,1~ lre supplied, via electrical conductors 17,18, 19 and 20, to an onalyser 21 which discloses the position Or the li~ht spot in the coordinate sys~em, either direclly or indirectly. The location of the light-spot 15 is identical with the position of the end 11 of the fibre ~, and h-.ving knowledge of the bending choracter-;stics of the fibre 9 and its length it is possible to give the incli-nation of the housin~ 1 relative to the vertical both directly and pre-cisely. The maximum ou~ward bending of the fibre 9 with an inclination of 90 can be given any desired value by selection or fibre materi~
fibre length and cross-sectional area. The cross-section~l orea need not be constont along the whole length of the fihre, ~lthough there is preferably used a fibre of uniform thickness ~nd of circular cross-sectian. As ~ill be understood, ~he measuring accuracy o~ the device depends upon the characteristics of the fibre and upon the detector detector of the kind described abov~ gives the position of the centre of the light spot with an accuracy of 10 meters, or hiaher. Depending upon the length and cross-sectional area of the flexible, resilient fibre 9, it is possible when using such a detector to obtain a measuri~
accurocy of 1 (one) microradian. When the demand for measuring accura-cy is not so high, it can be mentioned that an accurQcy of 0.01 can be obtained with a glass fibre having a length of ~bout 10 cm and a diameter of about 50 micrometers within a measuring range of + ~0.
The described device can be used within a multiplicity oF technicol fields Thus it con be used as a conventional plumb-bob and as n sensor in the automatic olianment of objects at a certain angle of in-clination, for example in the remote horizontalization of under-water apparatus. The device illustrated in Figure 1 can also be usedfor continuously rneasuring extremely smnll movements in -the earth s crust, thereby functioning as an avalanche early-warning system, and in loose deposits, thereby to act as an early warning system in the event of land slides etc The short reaction time of the Fibre, and similarly the short rise time of the described detector, about one microsecond, enables the device to be used as a vibration meter for determing vib.ration freouencies and amplitudes. It should be noted that the described electrode is only one of various kinds of photodetectors which can be used to detect the position of the free end or tip 11 of the fibre 9 relative to the vertical. In certain cases it may be suitable, and desirable, to arrange a system of lenses between the tip 11 of the fibre 9 and the detector 12.
It will ~e apparent that the device illustrated in Figure 1 is only intended to indicate angles of inclination, i.e. a function of the distance from the origin 16 ~nd the light spot 1~, and that it cannot be used in its illustrated state to show, for example, the presence of a bend in a bore in which the device is inserted In order for the device to indicate a crooked bore, it is provided with an optical system of the kind shown in Figure 3 for example~ In this embodiment the housing 1 is extended with a cylindrical part 1 .
Arranged in the lower end of the part 1 is a light source ~2, for example a liaht-emitting diode of the same kind as the light-emitting diode 7, said diode 2~ being supplied with a voltage over two elec-trical conductors 23 and 24. The light from the light-emitting diode 22 6 .~ 2 ~
is focused onto the underside of the detector 12 by means of o lens or a system of lenses 25. As will be seen from the draw;ngs, the de-tector 12 of the Figore 3 ernbodiment has been exposed by removing the bottom 26 in Figure 1 When the housing 1, 1 is free from nll bends, the light spot 27 generated by the lens arrangement 25 will lie on the origin 16 (Figure 2), but if the device is inserted into a bore which is somewhat crooked, the housing 1, 1 will bend slightly, causing the light spot 27 generated by the fixed lens arrangement 25 and the fixed light source 22 to move across the undersurface of the de-tector 12~ It will be noted tha-t if, as before described, only one detector 12 is used for two lighl spots 15 (Figure 2) and 27 (Figvre 3) it is necessary to alternately extinguish and i.lluminate the two light-emitti.ng diodes, in order for the detector 12 to give the correct values. To this end there is provided a voltage source 28 which ol-ternately supplies an ignition voltage to the diode 7 and the diode22, whereby only one light spot is projected onto the detector 12 at any given time. The X-Y-signals generatecl by the detector 12 are sent to a recorder 29, a data processor or same other like apparatus and the signuls generated by the light-emitting diode 7 and the light-emitting diode 22 respectively ~re separc1ted by synchronising pulsesfrom the voltage source 28 over a line 30.
It is also possible, o~ course, to use two mutually independent de-tectors superi~posed one upon the other, of which one is nrranged to co-act with the light-emitting diode 7, in the manner described with reference to Figure 1, and the other is arranged to co-act with the light-emitting diode 22.
For a closer explanation of the device according to Figure 3, reference is made to Figures 4a - 4c and Figures 5a and 5b. Figure 5a illustrates a bore in a horizontal X-~-plane, and it will be seen that the bore is sligh-tly curved in a clockwise direction. Figure 5b shows the same bore in an X-~-plane, which is vertical and in which the bore extends rectilinearly. In the Fiaure 3 embodiment the housing 1, 1 is assumed to be enclosed in a long tube, for example a liner tube, which is successively fed into the bore as the bore is being drilled. The hous-ing 1, 1 will therewith bend in a manner corresponding to that illu-strated in Fioure ~a, meaning that the light spot 27 will obtain a position relative to the origin 16 of the detector according to Figure 4a. It will be equally apparent that rotation of the housing 1, 1 about its long axis, which is unavoidable, will not alter the distance of the light spot 27 from the origin 16, and neither will the light spot 27 be moved relative to the point 1~ which indicates the inclination according to Figure 5. The angulnr position in the coor-dinate system will, of course, be changed with rotation of the coor-dinate system, as evident from Figures 4a - 4c. The light spot 15 will also take a specific position in the coordinate system, irrespective of the rotation of the housing 1, 1 about its longitudinol axis.
The radius of the bend in the bore at each separate measuring point is a function of the distance between the light spot 27 and the origin 16, since the housing 1, 1' exhibits the same bend and has, of course, a diameter substantiolly corresponding to the diometer of the bore.
The centre of the bend is calculated trigonometrically with aid of the coordinates of the light spot 15, which always lie in a vertical plane through the origin 16. Thus, irrespective of the position of rotation of the housing 1, 1 about its longitudinal axis, there can be obtained all of the values required for drawing up curves which show precisely the inclination and curvature of the bore, either direct-ly or with the aid of a data processor. The requisite voltage can be supplied to the equipment either from the ground surfcJce or from a voltage source incorporated in the housing 1, 1'. Similarly, the posi-tion signals can be sent tc the ground surface, via a cable, or therequisite circuits for successively s-toring and colculating positio-nal information can be incorporated in the housing 1, 1 ~ The housing 1, 1 should be relatively readily bendable, to allow it to pass bends of small radius The length of the housing 1, 1 is decisive in en-abling the bend to bè registered, and if great precision is desired, the housing should thus be long. Of course, the accuracy of the device depends upon the signal/noise ratio of the electronic circuits receiving the signals from .he detector or detectorsc The resolution power of a detector of the kind described is of the order of 10 meters With the aid of relatively simple electronic devices, it should be possible to determine the inclination to about ~ 0 01, ond the bend radius up to about 100 km. This means that in the worst of cases it is possible to determine the configuration of a bore having a length of 1000 meters with an error in the order of 5 meters, since with continuous measure-ment errors constantly accumulate with the same sign.
The present invention relates to a device for the dyn~mic measurement of inclinations relative to the verticalt comprising a resilient thre~d which is firmly held at one end in a holder and the other, free end of which is arranged to co-oct with a light source adapted to irradiate n light-sensitive detector means.
A device of this general kind can be constructed from the teachings of Swedish Patent Specification No 141 501 and the US P~tent Speci-ficr.tion No 3,324,564. The Swedish Specification 141 501 refers to n device having o flexible thread or rod whose free end is loaded with a weight which when the device is inclined causes the thread or rod to bend~ The bending stresses and strains occurring in the rod are de-tected by means of Q strain gauge. The U.S. Pater~t Specification No 3,324,564 relates to a device having a pendulum whose free end car-ries an incandescent lamp which is arranged to co-act with a light-sensitive detector in a manner to indicate the angle at whirh the pen-20 dulum is inclined to the vertical. Even though the rigid pendulum ofthe device nccording to the U.S. Patent Specification No 3 324 564 should be replaced with a flexible, loaded rod according to the Swedish Patent Specification No 141 501, it would still not be possible to provide an inclinometer which is sensitive and which reacts quickly, owing substantially to the relatively high mass of the part which indi-cates the angle of inclination.
Consequently it is a prime object of the invention to provide an in-clinometer of the kind set forth in the introduction which although comprising a combination of the devices disclosed in the two aforemen-tioned patent specifications is nevertheless very precise and reacts -~ - 2 -extremely rapidly, thereby enabling it to be used for indicating those settlements and subsidences which occur even with slight earth tremors. ~Iereinafter the inclinometer according to the invention is stated as being used mainly for measuriny -the inclination of a bore or drilled hole or the like.
A further object of the invention is to provide an inclinometer which will not only indicate any deviation from the vertical, but will also indicate the bend in a drilled hole or bore which is not straight.
According to the present invention, then, -there is provided a device for dynamically measuring inclinations from the vertical comprising a housing, a flexible optic fibre firmly held at one end thereof by a mount supported in the housing with the other end of the fibre being free to move in response to the inclination of the device, a light source located adjacent the firml~ held end for directing light through the fibre to the free end thereof, and light-sensitive detector means disposed proximal to -the free end such that light emerging from the free end creates a light spot thereon, wherein the detector means are responsive to the light spot to produce signals indicative of the position of the light spot relative to a predetermined point of reference on the detector means.
Embodiments of the present invention will now be described in greater detail and will be better understood when read in conjunction with the following drawings in which:
z~
Figure 1 is a simplified axial sectional view of an inclinometer according to the invention having a schematically illustrated inclination indicating means, Figure 2 illustrates a suitable, fundamental detector means for use in the inclinometer according to the invention, Figure 3 is a simplified view of an inclinometer according ko the invention for the simultaneous measurement of the curvature of a bore, Figures ~a, 4b and 4c illustrate the positions of the measuring ~0 points on the detector of the inclinometer when simultaneously measuring the inclination and curvature of a bore from a given line, and Figures 5a and 5b illustrate the inclination and the curvature of the device which gives rise to measuring point posi-tions illustrated in Figures 4a - 4c.
Fig. 1 is a simplified axial sectional view of a device according to the invention intended for determining deviations from the vertical. When the device of the illustrated embodiment is fully vertical, deviation from the vertical is zero.
The device illustrated in Figure 1 includes a housing 1, which in the shown embodiment is assumed to be cylindrical but which may have any cross-sectional configuration suit-able for the use to which the device is to be put. The housina 1 has an upper cap 2 provided with an opening 3 for a cable 4 having two electrical conductors 5 and 6 for supplying voltage to a light-emitting diode 7, or some other source of light radiation which produces infra-red, ultraviolet or visible light. Hereinafter it is assumed that the light source has the form of a light-emitting diode and that said diode is supplied with an alternating voltage having a frequency of, for example, 100Q H~. It will be understood, however, that any suitable frequency may be used and that the diode 7 may be supplied with a direct-current voltage. In the illustrated embodiment, the light-emit-ting diode 7 is mounted on the upper side of a plug 8, which form a holder for an optic fibre 9. The fibre 9 is firmly held at one end 10 thereof in the holder 8 while the remainder of the fibre is freely movable and is free of any load. The upper end 10 of the fibre ~ is arranged to co-act with the diode 7, and light from the diode will thus be transmitted to the free end 11 of the fibre 9. The free end 11 lies above a detector 12 and is located so close to the surface of the detector that a well defined, small spot of light is projected onto said surface.
The fundarnental principle of a suitable detector 12 is illustroted in Fioure 2. The detector 12 of the illustrated embodiment has the form of a known, so-called lateral photo detector which is constructed about a sauare plote comprisina a semi conductor material. The upper side of the plate is covered with a light-permeable gold 1ayer~ while the underside has a thin homogeneous layer of resistive materinl.
Arranged along the periphery of the resistive layer (not shown ), ad-jacent the edges of the plate, are two pairs of mutually opposite dis-charge electrodes 13,13 and 14,14. ~!hen a point 15 is illuminated, the light flow aives rise to a voltage/current source across the p-n-transition zone present in the doped plate. This voltage/current source is able to form a closed circuit vin srid gold layer and the resistive layer with the electrodes 13,13 and 14,14, and thus four part current-flows, one for each electrode, can be registered. The mog-nitude of these pnrt current-flows is dependent upon the distonce of the liaht spot 15 from the oriain 16 of the coordinates in the incor-porated XY-system The four current-flows tnken out through the elec--trodes 13,13 and 14,1~ lre supplied, via electrical conductors 17,18, 19 and 20, to an onalyser 21 which discloses the position Or the li~ht spot in the coordinate sys~em, either direclly or indirectly. The location of the light-spot 15 is identical with the position of the end 11 of the fibre ~, and h-.ving knowledge of the bending choracter-;stics of the fibre 9 and its length it is possible to give the incli-nation of the housin~ 1 relative to the vertical both directly and pre-cisely. The maximum ou~ward bending of the fibre 9 with an inclination of 90 can be given any desired value by selection or fibre materi~
fibre length and cross-sectional area. The cross-section~l orea need not be constont along the whole length of the fihre, ~lthough there is preferably used a fibre of uniform thickness ~nd of circular cross-sectian. As ~ill be understood, ~he measuring accuracy o~ the device depends upon the characteristics of the fibre and upon the detector detector of the kind described abov~ gives the position of the centre of the light spot with an accuracy of 10 meters, or hiaher. Depending upon the length and cross-sectional area of the flexible, resilient fibre 9, it is possible when using such a detector to obtain a measuri~
accurocy of 1 (one) microradian. When the demand for measuring accura-cy is not so high, it can be mentioned that an accurQcy of 0.01 can be obtained with a glass fibre having a length of ~bout 10 cm and a diameter of about 50 micrometers within a measuring range of + ~0.
The described device can be used within a multiplicity oF technicol fields Thus it con be used as a conventional plumb-bob and as n sensor in the automatic olianment of objects at a certain angle of in-clination, for example in the remote horizontalization of under-water apparatus. The device illustrated in Figure 1 can also be usedfor continuously rneasuring extremely smnll movements in -the earth s crust, thereby functioning as an avalanche early-warning system, and in loose deposits, thereby to act as an early warning system in the event of land slides etc The short reaction time of the Fibre, and similarly the short rise time of the described detector, about one microsecond, enables the device to be used as a vibration meter for determing vib.ration freouencies and amplitudes. It should be noted that the described electrode is only one of various kinds of photodetectors which can be used to detect the position of the free end or tip 11 of the fibre 9 relative to the vertical. In certain cases it may be suitable, and desirable, to arrange a system of lenses between the tip 11 of the fibre 9 and the detector 12.
It will ~e apparent that the device illustrated in Figure 1 is only intended to indicate angles of inclination, i.e. a function of the distance from the origin 16 ~nd the light spot 1~, and that it cannot be used in its illustrated state to show, for example, the presence of a bend in a bore in which the device is inserted In order for the device to indicate a crooked bore, it is provided with an optical system of the kind shown in Figure 3 for example~ In this embodiment the housing 1 is extended with a cylindrical part 1 .
Arranged in the lower end of the part 1 is a light source ~2, for example a liaht-emitting diode of the same kind as the light-emitting diode 7, said diode 2~ being supplied with a voltage over two elec-trical conductors 23 and 24. The light from the light-emitting diode 22 6 .~ 2 ~
is focused onto the underside of the detector 12 by means of o lens or a system of lenses 25. As will be seen from the draw;ngs, the de-tector 12 of the Figore 3 ernbodiment has been exposed by removing the bottom 26 in Figure 1 When the housing 1, 1 is free from nll bends, the light spot 27 generated by the lens arrangement 25 will lie on the origin 16 (Figure 2), but if the device is inserted into a bore which is somewhat crooked, the housing 1, 1 will bend slightly, causing the light spot 27 generated by the fixed lens arrangement 25 and the fixed light source 22 to move across the undersurface of the de-tector 12~ It will be noted tha-t if, as before described, only one detector 12 is used for two lighl spots 15 (Figure 2) and 27 (Figvre 3) it is necessary to alternately extinguish and i.lluminate the two light-emitti.ng diodes, in order for the detector 12 to give the correct values. To this end there is provided a voltage source 28 which ol-ternately supplies an ignition voltage to the diode 7 and the diode22, whereby only one light spot is projected onto the detector 12 at any given time. The X-Y-signals generatecl by the detector 12 are sent to a recorder 29, a data processor or same other like apparatus and the signuls generated by the light-emitting diode 7 and the light-emitting diode 22 respectively ~re separc1ted by synchronising pulsesfrom the voltage source 28 over a line 30.
It is also possible, o~ course, to use two mutually independent de-tectors superi~posed one upon the other, of which one is nrranged to co-act with the light-emitting diode 7, in the manner described with reference to Figure 1, and the other is arranged to co-act with the light-emitting diode 22.
For a closer explanation of the device according to Figure 3, reference is made to Figures 4a - 4c and Figures 5a and 5b. Figure 5a illustrates a bore in a horizontal X-~-plane, and it will be seen that the bore is sligh-tly curved in a clockwise direction. Figure 5b shows the same bore in an X-~-plane, which is vertical and in which the bore extends rectilinearly. In the Fiaure 3 embodiment the housing 1, 1 is assumed to be enclosed in a long tube, for example a liner tube, which is successively fed into the bore as the bore is being drilled. The hous-ing 1, 1 will therewith bend in a manner corresponding to that illu-strated in Fioure ~a, meaning that the light spot 27 will obtain a position relative to the origin 16 of the detector according to Figure 4a. It will be equally apparent that rotation of the housing 1, 1 about its long axis, which is unavoidable, will not alter the distance of the light spot 27 from the origin 16, and neither will the light spot 27 be moved relative to the point 1~ which indicates the inclination according to Figure 5. The angulnr position in the coor-dinate system will, of course, be changed with rotation of the coor-dinate system, as evident from Figures 4a - 4c. The light spot 15 will also take a specific position in the coordinate system, irrespective of the rotation of the housing 1, 1 about its longitudinol axis.
The radius of the bend in the bore at each separate measuring point is a function of the distance between the light spot 27 and the origin 16, since the housing 1, 1' exhibits the same bend and has, of course, a diameter substantiolly corresponding to the diometer of the bore.
The centre of the bend is calculated trigonometrically with aid of the coordinates of the light spot 15, which always lie in a vertical plane through the origin 16. Thus, irrespective of the position of rotation of the housing 1, 1 about its longitudinal axis, there can be obtained all of the values required for drawing up curves which show precisely the inclination and curvature of the bore, either direct-ly or with the aid of a data processor. The requisite voltage can be supplied to the equipment either from the ground surfcJce or from a voltage source incorporated in the housing 1, 1'. Similarly, the posi-tion signals can be sent tc the ground surface, via a cable, or therequisite circuits for successively s-toring and colculating positio-nal information can be incorporated in the housing 1, 1 ~ The housing 1, 1 should be relatively readily bendable, to allow it to pass bends of small radius The length of the housing 1, 1 is decisive in en-abling the bend to bè registered, and if great precision is desired, the housing should thus be long. Of course, the accuracy of the device depends upon the signal/noise ratio of the electronic circuits receiving the signals from .he detector or detectorsc The resolution power of a detector of the kind described is of the order of 10 meters With the aid of relatively simple electronic devices, it should be possible to determine the inclination to about ~ 0 01, ond the bend radius up to about 100 km. This means that in the worst of cases it is possible to determine the configuration of a bore having a length of 1000 meters with an error in the order of 5 meters, since with continuous measure-ment errors constantly accumulate with the same sign.
Claims (21)
1. A device for dynamically measuring inclinations from the vertical comprising:
a housing;
a flexible optic fibre firmly held at one end thereof by a mount supported in said housing with the other end of said fibre being free to move in response to the inclination of said device;
a light source located adjacent said firmly held end for directing light through said fibre to the free end thereof; and light-sensitive detector means disposed proximal to said free end such that light emerging from said free end creates a light spot thereon, wherein said detector means are responsive to said light spot to produce signals indicative of the position of said light spot relative to a predetermined point of reference on said detector means.
a housing;
a flexible optic fibre firmly held at one end thereof by a mount supported in said housing with the other end of said fibre being free to move in response to the inclination of said device;
a light source located adjacent said firmly held end for directing light through said fibre to the free end thereof; and light-sensitive detector means disposed proximal to said free end such that light emerging from said free end creates a light spot thereon, wherein said detector means are responsive to said light spot to produce signals indicative of the position of said light spot relative to a predetermined point of reference on said detector means.
2. The device of claim 1 including means for analyzing said signals to determine the position of said light spot relative to said predetermined point of reference, which position may be correlated to the angle of inclination of said device.
3. The device of claim 1 wherein said detector means comprise a plate-shaped member of semiconductor material, the surface thereof adjacent the free end of said optic fibre having a light permeable conductive layer formed thereon and the opposite surface thereof having a thin resistive layer formed thereon, two pairs of discharge electrodes provided at mutually opposite edges of said plate-shaped member and conductor means leading from each of said electrodes for transmitting said signals.
4. The device of claim 3 further including analyzer means for receiving said signals from said conductor means for determining the position of said light spot relative to said predetermined point of reference, which position may be correlated to the angle of inclination of said device.
5. The device of claims 1, 2 or 4 wherein said detector means comprise a lateral photodetector.
6. The device of claims 1, 2 or 4 wherein said detector means are disposed orthogonally to the undeflected longitudinal axis of said optic fibre.
7. The device of claims 1, 2 or 5 wherein said predetermined point of reference is located substantially at the centre of said detector means in alignment with the undeflected longitudinal axis of said optic fibre.
8. The device of claim 1 further including a second light source arranged in said housing to direct light onto the side of said detector means opposite said side thereof disposed proximal the free end of said optic fibre and means to focus the light from said second source onto said opposite side to form a second light spot, said detector means being responsive to the second light spot to produce signals indicative of the position of said second light spot relative to said predetermined point of reference.
9. The device of claim 8 wherein the distance between said second light source and said detector means is substantially greater than the corresponding distance between said first light source and said detector means.
10. The device of claim 8 wherein said first and second light sources are disposed adjacent opposite ends of said housing and wherein said housing is flexible such that the position of said second light spot on the opposite side of said detector means changes in response to the flexure of said housing.
11. The device of claim 9 including means for analyzing said signals indicative of the position of said second light spot for determining the position of said second light spot relative to said predetermined point of reference, which position may be correlated to the degree of flexure of said flexible housing.
12. The device of claim 10 wherein said first and second light sources are sequentially illuminated such that said first and second light spots are correspondingly formed in sequence whereby said signals generated by said detector means in response thereto may be separated for analyzing by said analyzing means.
13. The device of claims 8, 9 and 12 wherein said focusing means comprise lens means disposed between said second light source and said opposite side of said detector means.
14. The device of claims 1, 8 or 12 wherein said first and second light sources each comprise a light emitting diode.
15. The device of claims 8, 9 and 12 wherein said predetermined point of reference is located substantially at the centre of said detector means in alignment with the undeflected longitudinal axis of said optic fibre.
16. The device of claim 1 further including a second light source arranged in said housing to direct light onto a second light sensitive detector means arranged back to back with said detector means, and means to focus the light from said second source onto said second detector means to form a second light spot thereon, said detector means being responsive to said second light spot to produce signals indicative of the position of said second light spot relative to a predetermined point of reference on said second detector means.
17. The device of claim 16 wherein the distance between said second light source and the second detector means is substantially greater than the corresponding distance between said first light source and said detector means.
18. The device of claim 17 wherein said first and second light sources are disposed adjacent opposite ends of said housing and wherein said housing is flexible such that the position of said second light spot on the opposite side of said detector means changes in response to flexures of said housing.
19. The device of claim 18 including means for analyzing said signals indicative of the position of said second light spot for determining the position of said second light spot relative to said predetermined point of reference, which position may be correlated to the degree of flexure of said housing.
20. The device of claim 19 wherein said focusing means comprise lens means disposed between said second light source and said second detector means.
21. The device of claim 20 wherein said predetermined point of reference is located substantially at the centre of said second detector means in alignment with the undeflected longitudinal axis of said optic fibre.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| SE8002997-8 | 1980-04-22 | ||
| SE8002997 | 1980-04-22 | ||
| SE8101381A SE448918B (en) | 1980-04-22 | 1981-03-03 | DEVICE FOR DYNAMIC Saturation of slope in the ratio to the solder line |
| SE8101381-5 | 1981-03-03 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1156828A true CA1156828A (en) | 1983-11-15 |
Family
ID=26657548
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000375258A Expired CA1156828A (en) | 1980-04-22 | 1981-04-10 | Device for the dynamic measurement of inclinations |
Country Status (8)
| Country | Link |
|---|---|
| AU (1) | AU537772B2 (en) |
| CA (1) | CA1156828A (en) |
| DE (1) | DE3115838C2 (en) |
| DK (1) | DK150079C (en) |
| FI (1) | FI811026L (en) |
| FR (1) | FR2480934A1 (en) |
| GB (1) | GB2074315B (en) |
| NO (1) | NO156544C (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4627172A (en) * | 1984-08-17 | 1986-12-09 | Innovation Associates | Inclinometer having two degrees of freedom |
| US4812654A (en) * | 1986-12-29 | 1989-03-14 | The Charles Stark Draper Laboratory, Inc. | Two-axis quartz fiber passive tilt meter |
| CH674574A5 (en) * | 1988-03-30 | 1990-06-15 | Industrieorientierte Forsch | |
| DE3932053A1 (en) * | 1989-09-26 | 1991-04-04 | Rheinische Braunkohlenw Ag | Measuring escarpment movement using measuring probe - introduced through guide pipe inserted into ground and accepting target disc and light beam |
| US11059502B1 (en) | 2020-07-09 | 2021-07-13 | Bnsf Railway Company | Avalanche slide detection system and method |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SE141501C1 (en) * | 1950-10-13 | 1953-08-04 | ||
| US3324564A (en) * | 1963-04-01 | 1967-06-13 | Randall J Wright | Level with electrically responsive instrument |
| SE334752B (en) * | 1969-06-23 | 1971-05-03 | Bolinder Munktell | |
| US3602037A (en) * | 1969-07-09 | 1971-08-31 | Franklin D Neu | Apparatus for measuring minute deflections |
-
1981
- 1981-04-02 FI FI811026A patent/FI811026L/en not_active Application Discontinuation
- 1981-04-09 GB GB8111160A patent/GB2074315B/en not_active Expired
- 1981-04-10 NO NO811242A patent/NO156544C/en unknown
- 1981-04-10 CA CA000375258A patent/CA1156828A/en not_active Expired
- 1981-04-10 AU AU69372/81A patent/AU537772B2/en not_active Ceased
- 1981-04-21 DK DK176281A patent/DK150079C/en active
- 1981-04-21 FR FR8108069A patent/FR2480934A1/en active Granted
- 1981-04-21 DE DE3115838A patent/DE3115838C2/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DK176281A (en) | 1981-10-23 |
| NO156544B (en) | 1987-06-29 |
| FI811026L (en) | 1981-10-23 |
| DE3115838A1 (en) | 1982-02-18 |
| DE3115838C2 (en) | 1984-02-23 |
| NO811242L (en) | 1981-10-23 |
| AU537772B2 (en) | 1984-07-12 |
| DK150079C (en) | 1987-07-13 |
| GB2074315B (en) | 1983-10-19 |
| GB2074315A (en) | 1981-10-28 |
| FR2480934A1 (en) | 1981-10-23 |
| DK150079B (en) | 1986-12-01 |
| AU6937281A (en) | 1981-10-29 |
| NO156544C (en) | 1987-10-07 |
| FR2480934B1 (en) | 1984-11-16 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |