Data processing: measuring – calibrating – or testing – Measurement system – Orientation or position
Reexamination Certificate
2000-03-01
2002-10-29
Assouad, Patrick (Department: 2857)
Data processing: measuring, calibrating, or testing
Measurement system
Orientation or position
C356S003000
Reexamination Certificate
active
06473716
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a non-prism type lightwave range finder or the like which measures a distance to an object without having to use a corner cube, and particularly to a lightwave range finder and a measuring method, which are capable of computing arbitrary three-dimensional coordinate positions, distances and areas or the like from distance and angular data, etc.
BACKGROUND ART
A lightwave range finder capable of measuring distances without having to use a corner cube has heretofore been in existence. This type of conventional lightwave range finder
9000
comprises a light source
9100
, a collimator lens
9200
, a fiber
9300
on the light-emitting side, a prism
9400
, an objective lens
9500
, a fiber
9600
on the light-receiving side, a light-receptive lens
9700
and a light receptor
9800
.
The light source
9100
makes use of a pulse semiconductor laser and is pulse-driven by a laser driving circuit. A lightwave pulse emitted from the light source
9100
is introduced into the fiber
9300
on the light-emitting side through the collimator lens
9200
so as to be launched into the prism
9400
. Further, the lightwave pulse reflected by the prism
9400
passes through the objective lens
9500
so as to be radiated toward an object to be measured.
After the lightwave pulse reflected from the object to be measured has passed through the objective lens
9500
, it is reflected by the prism
9400
, followed by launching into the fiber
9600
on the light-receiving side. Further, the lightwave pulse introduced by the fiber
9600
on the light-receiving side is launched into the light receptor
9800
through the light-receptive lens
9700
. The lightwave pulse received by the light receptor
9800
is converted to an electric signal, which in turn is processed by a suitable arithmetic processing means to thereby obtain a distance-measuring value.
The fiber
9300
on the light-emitting side makes use of one whose diameter is normally about several hundred &mgr;m. This originates from the fact that the size of a light-emitting unit of the pulse semiconductor laser serving as the light source for emission is about several hundred &mgr;m.
As the objective lens
9500
, one is used wherein an effective diameter thereof is several tens of mm and a focal length thereof is about 100 mm. This results from a widened angle of the light-emitting unit of the pulse semiconductor laser serving as the light source for emission. Namely, this is because the objective lens
9500
needs to cover a certain degree of solid angle for the purpose of emitting produced light from the objective lens
9500
with good efficiency.
Further, the pulse light radiated toward the object to be measured from the objective lens
9500
spreads as it propagates far away because the diameter of the fiber
9300
on the light-emitting side has a finite size. If the focal length of the objective lens
9500
is regarded as 100 mm and the diameter of the fiber
9300
on the light-emitting side is 100 &mgr;m, for example, then the pulse light is spread to 100 mm as it is kept away by a distance of 100 m.
Thus, since the magnitude of a measuring ray bundle, which is applied to the object to be measured, reaches several ten of mm or more, the lightwave range finder
9000
freed from the use of the corner cube actually measures a surface without measuring points on the surface of the measuring object.
The measurement of a building
8000
through the use of the corner cube-free lightwave range finder
9000
will now be explained based on FIG.
7
.
Now consider where the sides of the building
8000
are measured.
When the corner cube-free lightwave range finder
9000
is installed at a point A to measure a point C of the building
8000
, it can measure the point C without any problem in practice since the size of the point C corresponding to the object to be measured is sufficiently greater than the magnitude of the measuring ray bundle.
However, when the size and position of a specific portion of the building
8000
shown in
FIG. 7
are measured, it is necessary to measure a specific corner. When, for example, a point D corresponding to the corner is measured, a surface including the corner is actually measured because a measuring ray bundle has a certain degree of magnitude even if measuring light is applied to the point D, whereby the corner cannot be measured accurately.
Further, when the corner cube-free lightwave range finder
9000
is placed in a point B to measure a point E of the building
8000
, measuring light is applied not only to the point E but also to the sides thereof, so that the resultant measured value results in one received from the measuring light applied to the two surfaces, thus causing a problem that the point E corresponding to the corner cannot be measured accurately.
A survey of a cylindrical column
7000
will next be described based on FIG.
8
. There may be cases where the measurements of the positions of an electric-light pole and trees or the like are required upon a survey under the present conditions. Now consider where the cylindrical column
7000
is measured by a normal lightwave range finder
9001
.
FIG. 9
is a diagram showing this state as viewed from above. First of all, a user places a corner cube
9002
on the surface of the cylindrical column
7000
. Further, the user makes use of the normal lightwave range finder
9001
to measure a distance L to the corner cube
9002
.
Next, the radius R of the cylindrical column
7000
is measured with the eye or through the use of a surveying tape or the like.
Further, a distance L′ to the center o of the cylindrical column
7000
can be determined by the following equation:
L′=L +R
However, while the distance L to the surface of the cylindrical column
7000
can be measured without the installation of the corner cube
9002
where the corner cube-free lightwave range finder
9000
is used, the diameter R of the cylindrical column
7000
cannot be obtained. Therefore, a problem arises in that the distance L′ to the center O of the cylindrical column
7000
cannot be obtained.
If an operator approaches or comes up to the cylindrical column
7000
and measures the radius R of the cylindrical column
7000
with his or her eyes or by using the surveying tape or the like, then the distance L′ to the center O of the cylindrical column
7000
can be determined. However, a problem arises in that if the operator approaches an object to be measured, there is little merit in using the corner cube-free lightwave range finder
9000
and work simplification cannot be achieved.
Accordingly, a serious problem arises in that while the corner cube-free lightwave range finder
9000
has an excellent merit that it is unnecessary to place the corner cube in a measuring position, it is difficult to measure each corner of a measured object because a measuring ray bundle has a finite magnitude, so that the outside shape, size and the like thereof cannot be measured accurately.
DISCLOSURE OF INVENTION
The present invention can specify at least three points on a plane a including measuring points of an object to be measured, measure distances to and angles relative to at least three points corresponding to the specified points as viewed from a point of origin, determine an equation for specifying the plane &agr;, using data about the distances and angles, collimate the measuring points from the point of origin to thereby measure angles, determine an equation indicative of a straight line connecting between the point of origin and each measuring point, and compute a measuring point corresponding to a point where the equation for specifying the plane &agr; and the equation indicative of the straight line connecting between the point of origin and each measuring point intersect.
The point of origin employed in the present invention may also be defined as a point where a surveying apparatus or surveying equipment is installed.
Further, the surveying equipment according to the present invention can also be def
Ohishi Masahiro
Takanashi Masaki
Assouad Patrick
BakerBotts LLP
Kabushiki Kaisha Topcon
LandOfFree
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