JPH02130408A - Coordinates measuring machine - Google Patents

Abstract

PURPOSE: To execute a number of different measurement topics accurately in all spatial directions at a low cost by using a link mechanism that needs not support weight at all and a measurement system that is added to it. CONSTITUTION: Three angle encoders are incorporated in rotary joints 11, 12, and 13 and angle positions α, ', and γ that are rotated or turned are measured. The position of the a probing ball 19 at the probing pin of a probing head 7 is decided uniquely by also considering known lengths a1 and a2 of a member between rotary axial lines of joints 11 and 12 or 12 and 13 and a lead-out length L of a measurement arm 5 of a height measuring machine. The rotary detector of the joints 11, 12, and 13 and the detection system of a scale 8 of a height measuring machine 2 are connected to a computer 17, and the computer 17 calculates and displays the position of the probing ball 19 at Cartesian coordinates from obtained angles α, β, and λ, measured height value Z, and parameters a1 , a2 , and L that are obtained in advance.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for determining the coordinate values of a probe element and a coordinate measuring machine operating on the basis of the method.

Multiple coordinate measuring machines exist in a wide variety of embodiments.

Exists. Paper by M. Dietsch and H. Lang (
"Precision work technology and measurement technology" Volume 86, 1978, P2
62-269) give an overview of the various structural types. All measuring machines described there are based on the same structure in principle. That is, each measuring device consists of six guide parts arranged at right angles to each other and overlapping each other, and three linear scales attached to the guide parts. The probe head is movable along the section.

Since the first guide must in each case bear the weight of the other guide constructed superimposed on it, deformation during the measurement process must be prevented in order to obtain a sufficiently high measurement accuracy. However, a rigid structure is required for the guide. Therefore, the coordinate measuring machine line is an expensive and luxurious precision instrument.

Coordinate measuring machines that perform measurements in spherical or cylindrical coordinates rather than in Cartesian coordinate systems are also known. Thus, for example, GB 149800 describes such a coordinate measuring machine. In the case of this measuring machine, the probe head is operated by three joints arranged one after the other.
held movably. The position of the probe head is determined in this measuring machine using an angle detector arranged in the joint. A coordinate measuring machine with a similar configuration is disclosed in U.S. Patent No. 424.
It is disclosed in the specification of No. 0205. In this measuring machine, the probe head is fixed to a vertically movable main shaft, which itself has a vertically arranged axis of rotation and, via three joints, rotates in 1,000 planes. being guided. The position of the main axis in the same plane is measured using a scale and a rotation detector.

In the latter two measuring machines, which use a rotary shaft for guiding the probe head instead of a linear guide, the movable parts of the measuring machines are also supported one on top of the other. Therefore, a counterweight is required to accommodate approximately 9 movable mechanical parts. However, this means that
It means an increase in the amount of mechanical parts that are moved, ie the mass. Moreover, the bearing structure of the rotating shaft must support the weight of the members installed on it each time.
It needs to be made very solid.

Nevertheless, it is not possible to carry out sufficiently accurate measurements using this measurement. This is because the individual members of the linkage are subject to variations in the loading conditions during the measurement and therefore cannot be restrained from deformation.

Furthermore, so-called height measuring machines are known.

This measuring device consists of a support body that can be freely moved manually within a plane, and a length measuring section is guided on the support body so as to be movable in the vertical direction. At various positions on the plane using the scale attached to the guide part,
Only the height of the probe from the same plane is measured and reported. The position of the height measuring device within the plane is not detected. In short, the probe head of the height measuring machine can only be displaced along the vertical line.

This known height measuring machine is therefore not a multi-coordinate measuring machine, since it serves only one-dimensional measurements. Indeed, height measuring machines are also known which are guided in two coordinates via a link guide and whose position coordinates in a plane are detected by means of a scale attached to the link guide. However, this measuring machine also conforms to the principle structure mentioned in the introduction of the known multicoordinate measuring machine, so that, inter alia, vertical errors in the guide directly influence the measuring result. It has the following drawbacks. Moreover, this known measuring machine cannot be rotated, so that a rotary table for the workpiece to be measured is additionally required.

DE 3,205,362 and DE 3,629,689 disclose a coordinate measuring machine based on a probe element that is guided manually or robotically onto the workpiece to be measured. The probe element is measured using a Rede telemeter from various directions. However, this measuring device allows for appropriate adjustment of the angle of the probe element only at great cost, and even then this adjustment is not possible at all positions in the measurement space. It has its drawbacks. Moreover, the probe element cannot be easily rotated around the workpiece to be measured. This is because in that case at least some of the measuring beams will be blocked.

The object of the invention is to detect coordinate values of probe elements that make it possible to carry out a large number of different measurement tasks with sufficiently high precision in all spatial directions at the lowest possible cost. The object of the present invention is to present a method and to provide a coordinate measuring machine useful for carrying out the method.

This object is achieved by the features of claims 1 to 7.

The solution of the invention has many advantages. The support of the probe head rests on a flat guide plate and is freely movable there either manually or by motor. The position of the support in the plane can therefore be ascertained using a linkage and an associated measuring system that do not require any weight bearing. This linkage is simply pivoted to one end of the guide plate and the other end of the support and can be supported on the guide plate, for example also via an additional air bearing. Therefore, no large rotating shaft or counterweight is required, so that the entire arrangement has a low mass and is easily moved. The link mechanism itself is not subjected to any load and no strain occurs in the link mechanism, thus improving the measurement accuracy of the measuring machine. Furthermore, no guides constructed overlapping one another are used, so that vertical errors in determining the plane coordinates are avoided. The configuration of the invention makes it possible to provide coordinate measurements that are compact and simple in construction and at the same time have good accessibility to the measurement space.

The linkage or linkages that engage the support with the guide plate can be configured in various types and ways.

It is thus possible, for example, to use one linkage consisting of six rotation axes, or one linkage consisting of two rotation axes and one pull-out member of variable length, or even two linkages. It is even possible to prepare one. The position of the support in the plane is easily detected by means of an angle detector attached to the rotation axis or a scale attached to the variable-length pull-out member. in this case,
Calculation of exact coordinate values is performed by an electronic calculator connected to each measurement value detector, based on the signals from the measurement value detector.

It is particularly advantageous if one or several linkages are pivotally mounted on the upper end of the support, where they cannot collide with workpieces arranged on a flat guide plate. . In this case, the support can be rotated freely through 360° around the workpiece, so that a separate rotary table for the workpiece is not required.

It is particularly advantageous for the distance between the vertical axis of rotation, on which the link mechanism is pivotally mounted, and the probe ball to be as small as possible. This is because the smaller the distance, the less accurate the angle measuring system used to measure the angle of rotation. Or, in that case,
This is because the angle detector is not required to have particularly high resolution.

In order to satisfy this condition geometrically, the support is advantageously provided with a C-shaped configuration by erecting thin supports on a substrate with a relatively large cross-sectional area. . This column has an arm protruding along the direction of the probe pin at the upper end. A rotary joint is disposed on this arm, and the link mechanism is connected to the height measuring machine via the rotary joint. combined.

Furthermore, in this case, the workpiece table is provided with a centrally arranged narrow foot so that the support can pass its substrate under the table surface and thus gain access to the workpiece. There is. This shape of the work table provides further advantages. This is because the table legs can be used as reference points for the linkage. If the linkage is rotatably pivoted to the workpiece table on this foot swivel, the support can likewise freely rotate through 360° around the workpiece swivel.

In order to increase the measurement accuracy as much as possible, it must be ensured that no measurement errors occur due to tilting of the support about the vertical axis. A measuring system for measuring the distance to the guide plate is arranged in the substrate of the support, or an inclination 1
c This measurement error can be corrected by directly attaching the electronic level to the support.

When working with a sensor that measures the distance to the surface of a flat guide plate, the accuracy of the guide plate or the deviation of the topography of the guide plate from an ideal plane does not affect the measurement results. In order to eliminate this influence, it is expedient to determine the tobograph of this flat guide plate in advance in a separate modification operation and to store it as a two-dimensional modification matrix.

A coordinate measuring machine operating according to the method of the invention can be moved manually or can be equipped with a drive for moving the support in a plane.

A drive of this type should preferably engage the center of gravity of the support. This achieves high transport speeds and accelerations. However, such a drive device may in some cases prevent the free rotation of the support through 660°.

In that case, either the workpiece is placed on a rotary table, thus ensuring free access from all directions, or the workpiece is fixedly mounted on both sides with two identical measuring instruments. It will be measured.

Further advantages of the invention will become apparent from the following description of an exemplary embodiment, based on the accompanying FIGS. 1 to 10. FIG.

The invention will now be described with reference to illustrated embodiments.

The coordinate measuring machine shown in FIG. It is possible to move. This height measuring machine is composed of a vertical support 3 along which a carriage 4 is movable in the height direction, that is, in two directions. To measure the Z coordinate, the column 3 is equipped with a scale 8 9 which is scanned by a photoelectric detection system, not shown, in the carriage 4 . An arm 5 is supported within the carriage 4 so as to be movable in the horizontal direction.

The arm 5 carries a probing head 7 at its end and
Tightening within the carriage 4 is done by means 6
Tightening is fixed via the lever shown.

The weight of carriage 4, measuring arm 4 and probe head 7 is balanced by a counterweight guided in column 3.

The height measuring device 2 is mounted on a support post 3 so that it can be moved without friction.
surface plate 1 via an air bearing integrated within the pace 9 of the
Supported above.

However, the probe head 7 is not a one-dimensional length measuring probe, but a six-dimensional probe head effective in all three directions, for example of the type described in US Pat. No. 4,177,568.

The height measuring device described here on the basis of FIG. 1 is also a component of the embodiments of FIGS. 2 to 4 in the same configuration.

As already detailed at the beginning, a height measuring machine simply
It is only necessary to know the height 2 of the measurement point probed by the probe head 7. In order to be able to grasp the coordinates X and Y in the plane of the surface plate 1 from a measurement technical point of view, the base 9 of the height measuring device 2 is connected to the fixed surface plate 1 via a link mechanism 18. There is.

The link mechanism 18 consists of two members, the first member being rotatably supported by the first rotary joint 11 with respect to the holding plate 10 fixed to the surface plate 1 with screws, and the second member The member is connected to the first member by a second rotary joint 12 and is pivotally connected to the height measuring machine 20 base 9 by a third rotary joint 13. Thereby, the link mechanism 18 allows the height measuring device 2 to move freely and does not need to support any load other than its own weight. Therefore, the linkage is connected to the rotary joint 11
, 12° and 13 supports can be manufactured inexpensively. Furthermore, the dead weight of the linkage 18 is supported by an air bearing attached to the lower part of the joint 12, so that no load conditions change with respect to the support of the rotary joint during the measurement process. That is, the movement of the height measuring machine does not exert any force on the components of the machine that are important from a measuring technology.

Three angle encoders are built into the three rotary joints 11, 1, and 13, and the angular positions α and β of the rotated or pivoted member are determined by the angle encoders.
, r are measured. Joints 11 and 12 or 12 and 13
The position of the probe 19 in the probe of the probe head 7 is uniquely determined by taking into account the known length a1+a2 of the member between the rotation axes of the Ru.

The rotation detectors of the joints 11, 12, 13 and the detection system of the scale 8 of the height measuring device 2 are connected to a calculator 17, which calculates the obtained angles α, β, γ and the measured angles. the height value 2 and the previously obtained parameter a1e
From a2 and L, the position of the probe 19 in Cartesian coordinates is calculated and displayed.

The length al*a2 of the linkage 18 cannot be changed and can be stored in the calculator 17 as a constant parameter. On the other hand, the length L of the measuring arm 5 to be pulled out can be changed by loosening the lever 6, and can be adapted to various measurement tasks.

However, it is not necessary to determine the pull-out length L of the arm 5 using an additional scale. Rather, the coordinate measuring machine consisting of the height measuring machine 2 and the link mechanism 18 can be adjusted using a calibration device arranged within the measuring range of the measuring machine after changing the pull-out length Li and retightening the arm 5. , newly calibrated. For this purpose, for example, the measuring points of the calibration device are engaged many times from distinctly different positions on the height measuring device 2.

By comparing measurements at various locations, the unknown withdrawal length L is determined heuristically.

The embodiment shown in FIG. 2 differs from that shown in FIG. 1 with respect to the structure of a link mechanism 2B that pivotally connects the height measuring device 2' to the surface plate (granite) 1. The linkage 2B consists of a variable length drawer member 26 supported within the linear guide 22. This guide part 22 is rotatably connected to a holding member 20iC fixed to a surface plate with screws via a first rotary joint 21, and a drawer member 26 equipped with a length scale 24 is The height measuring device 20 is connected to the base via a second rotary joint 23 .

In the guide 22 of the drawer member 26 there is a detection system 25 which scans the scale 24 . Here too, the joint 21.23 is equipped with an angle encoder for measuring the rotation angles δ1 and δ2 between the link mechanism and the base and between the base and the height measuring device 2.

The calculator 27 of the measuring machine calculates the coordinates X, Ye Z'l of the probe sphere of the probe head of the height measuring machine 2, the rotary joint 21.
The measured value of the angle detector in 23 δ1. It is calculated from δ2, the measured pull-out length γ□ of the link mechanism 28, and the length L of the measuring arm 5 of the height measuring device 2 determined by calibration.

The embodiment of FIG. 6 includes two linkers of the type described on the basis of FIG. A coordinate measuring machine is shown which is used in 38.48 to determine the in-plane position of the surface plate.

For this purpose, the holding member 30 is
and a first link mechanism 3 rotatably connected to the surface plate.
The drawer member 36 of B is the first length scale/I/34
't, the drawer member 46 of the second linkage 4B, which is provided and which is also pivotable relative to the second holding member 40 via the second rotary joint 41e, has a homogeneous length scale 4
It is equipped with 4.

Both scales are connected to the linear guide section 3 of the linkage 38.48,
scanned by a corresponding detector 35.45 in 42;
And the measured value γ of the pull-out length of both link mechanisms,
Provides γ3.

Both link mechanisms are fixed to a surface plate at one end with a constant distance from each other, and are pivotally connected to the pace of the height measuring device 2 via a double joint 33 having a common rotation axis. ing. Only the joint 33 has both drawer members 36,
An angle encoder is arranged which measures the angle of rotation of the height measuring device 2 relative to one of the height measuring devices 46 .

Distance between the bases of both link mechanisms and pull-out length 2vr
If 3 is understood (a triangle with known side lengths is established), the position of the rotation axis of the joint 330 within the plane of the surface plate is uniquely determined. With this position as the origin, the position of the probe ball is
It is calculated based on the measured value δ3 of the angle encoder in 3 and the length L of the measuring arm of the height measuring device 2. The trigonometric calculations necessary for this purpose are carried out by a calculator 37, which is connected to the output of the measurement value detector mentioned above.

In this embodiment, the linkage certainly requires a lot of space and limits the range of motion of the measuring machine and the available measurement range. However, the same linkage offers the advantage of a relatively high achievable precision.

In the case of the embodiment shown in FIG. 4, the plane coordinate X.

The link mechanism 5B used to measure Yl is pivotally attached to the upper end of the column of the height measuring device 2. This link mechanism 58 is composed of a rod, and one end of the rod is movably connected to the height measuring device 2 in all directions via a first Cardan type double joint 53. There is. The rod 56 is movably supported in a sleeve which is likewise cardanically mounted on the second joint 52 and which is connected to an element 51 of the fixed support 50 that projects above the measurement area. has been done. Inside this sleeve there is a detection system for a linear scale 54 attached to a rod 56.

Furthermore, two rotation detectors are arranged on the Cardan joint 52 for measuring the angle ψlψ2, which is the angle that the rod 56 makes with respect to the base 1 of the height measuring device 2. be. Furthermore, a rotation detector is disposed in the joint 53 at the top of the height measuring device 2 to measure the angle ψ, which is determined when the height measuring device is rotated around the vertical axis. is the angle of

From the measured value r4 of the length of the scale 54, the angles ψ1, ψ, ψ3 of the angle encoder, and the binary values of the scale of the height measuring device 2, the calculator 57 of the coordinate measuring device calculates the Cartesian exploration method of the measuring device. Calculate the coordinates X, Y, Zt'.

At this time, polar coordinates r4. ψ1. ψ2 is transformed into a Cartesian coordinate system projected onto the plane of the surface plate.

As a result of the link mechanism 5B being pivotally attached to the upper end of the height measuring device 2, the mobility of the height measuring device within a plane is least susceptible to interference compared to other embodiments.

Another embodiment of the invention is shown in FIG. 5, in which the linkage is similarly pivotally mounted to the upper end of the height measuring machine. In this embodiment, the height measuring device 102 has a C-shaped shape in a superimposed cross section, and a base plate 109 constitutes the lower leg of the C-shape. A vertical support 103 is erected above. This support 103 has a carriage 104 for the probe head 107.
is supported so as to be movable in the vertical direction. This carriage 104 is equipped with a yoke 106, and using the yoke, the measuring instrument 102 can be moved on a flat surface plate (granite) 101, and the height of the exploration head 107 can be adjusted. be.

The upper part 108 of the support body 103 protrudes toward the tip of the probe pin and forms an upper leg of the letter 0. A sliding member equipped with a scale for measuring the position of the height measuring device in the planes X and Y is rotatably mounted on this forwardly projecting portion 108, and its axis of rotation is Indicated by A. In this case, the position of this axis of rotation is such that the coaxial line passes through the center point of the probing method Tk of the probing head 107 or is only a short distance away from the center point.
Selected.

Two pillars 110° and 120 are fixed to the rear surface of the surface plate 101. Both of the pillars carry rotation bearings on their upper surfaces, and due to the rotation bearings, the holder 111 is placed at the same position.
, 121 mm and connected 113, 123
is rotatably held as in the embodiment of FIG. As is clear from FIG. 6, the sliding keys 113 and 123 are provided with a scale grating 119 on their lower surfaces.

The sliding rod is supported so as to be linearly movable within guide cages 114 and 124 which are rotatable about the axis A at the upper end of the height measuring machine.
It protrudes beyond the front of 2. Of course, it is also possible to attach the sliding keyaki so that it extends beyond the supports 111 and 120 to the rear.

If the requirements for measuring accuracy are relatively low and a tape measure is used instead of a rigid slide bar, protrusion of the slide bar is avoided. In this case, the tape measure is guided inside the columns 110, 120 via a deflection roller,
It is held under tension by a spring attached to it.

The slide rods 113, 123 each carry one counter/ter weight 112, 122 at their rear ends. With this counterweight, the salary is 113,12
3 is balanced and abuts against the upper surface of the support 103 without any load.

Thereby, even if the distance between the height measuring device 102 and the support column 110 or 120 changes, fluctuations in the load state can be avoided.

The method of connecting the column 110 and the height measuring device 102t by the slide rod 113 is shown in more detail in FIG. In partial section, the rotation bearing 117 is on the upper side of the column 110 and the rotation bearing 129 is on the upper side of the height measuring machine 108.
recognized within. An angle encoder 12B is arranged on the latter bearing 129, which measures the rotational position of the height measuring device 1020 relative to the orientation direction of the slide rod 113. The casings 114, 124 in which the slide rods 113, 123 are guided longitudinally also contain a photoelectric incremental detection system, which detects the linear scales in the slide rods 113, 123. The graduation grating 119 shown in FIG. 6 is scanned.

Both struts 110, 120 are connected to each other at their upper ends by a rod 118 with a small coefficient of thermal expansion, such as an impur.

This measure plays a particularly important role. This is because the spacing between the two supports, or the distance between the centers of rotation carried by the same supports, is sufficient for measuring the plane coordinates of the height measuring device 102, as will be further explained with reference to FIGS. 9a and 9b. This is because the base ft is configured. In addition, if the linear scale is likewise made of a material with a low coefficient of thermal expansion, or if the thermal expansion of the rod and scale is determined by temperature measurements, then the height in the axis of rotation A or in the planes X, Y The position of the measuring instrument is determined with very high accuracy.

The workpiece to be measured is designated at 117 in FIG. The workpiece is placed on a workpiece table, and the plate 115 of the table is fixed onto the surface plate 101 via a thin foot 116 attached to the center. By this measure, and in connection with the rotatability of the height measuring machine with the slides 113, 123 mounted on the upper part, the height measuring machine 102 is completely attached to the workpiece 1170 times. It becomes possible to walk around or measure a workpiece from all sides.

The above-mentioned rotatability of 360° in the rotation of the workpiece is
Otherwise, this is also achieved in the embodiments shown in FIGS. 1 and 2. This is accomplished as follows. That is, the workpiece table is likewise mounted in the measurement area with a single, centrally mounted foot, and a stationary, designated 10 or 20, for a single linkage. This is achieved in that the reference point is located under the workpiece table rather than at the edge of the measurement area, and that the linkage is rotatable with the rotation of the table foot. In this case, no pivoting at the upper end of the height measuring device is necessary.

A large number of measurement problems can be solved using a coordinate measuring machine configured as illustrated in FIG. For such measurement tasks, for example in the case of inclined holes or rotating parts in prismatic workpieces, expensive circular tables or well-shaped probes or rotary and oscillating joints have not been necessary. there was.

The sliding rods 113, 123 with linear scales of the embodiments according to FIGS. 5 to 7 can alternatively be replaced by a light wave interference sub-length system. The system is particularly advantageous when the desired measurement length is large and the use of a sliding payload would make it unwieldy. An embodiment modified for large measurement lengths is shown in Figures 3a and 9b. According to this, a laser light source 412 including an interferometer 415 is provided on a rotatably supported plate 411 at each of the six pillars at the rear end of the surface plate 101 . In FIG. 8a, the relevant strut is designated 410. Upper part 108 of height measuring machine
A support plate 414 is attached to the rotary bearing 129, and a reflecting prism 421 whose length is measured by an interferometer 415 is fixed to this support plate. The second reflecting prism 422 is rotatably supported on the support of the prism 421, and its length is measured by a second interferometer (not shown) on another support. The support plate 414 is connected to the measuring beam 4 of the interferometer by means of a tensile shear wire 416.
13 is always adjusted so that it is perpendicularly incident on the reflecting prism 421. For this purpose, the tension shear 416 is
It is guided via two rollers 418, 419 on a rotatable plate 411. The tension of the wire is ensured by the counterweight 420. This counterweight is guided within a hollow column 410. The second prism 422 is also provided with corresponding means for adjustment.

Using two interferometric measuring beams 413 and 423, the horizontal plane
, Y can be unambiguously determined based on simple trigonometric relationships. This is the 9th a.
It is immediately clear from the diagram. There, columns 110, 12
The distance between the two rotational axes of 0 is indicated by L, and the distance measured by the scale or interferometer system from each rotational axis to the rotational axis A of the height measuring device is r4 or r5. It is shown in

In order to carry out coordinate measurements, however, it is necessary to know the exact position of the probe sphere Tk in the plane. For this purpose, a height measuring device 102 or a support 103 is also required.
The 0 rotation position must be determined. This is carried out by the angle detector 12B (Figs. 7 and 8a), which detects the angle δ4 formed between the probe pin axis and either the slide rods or one of the measurement beams. . Thereby, after knowing the distance 1 between the exploration sphere Tk and the axis of rotation A, the coordinates x and y of the exploration sphere within the plane can be calculated.

This distance 1 is shown enlarged in FIG. 9a. It is expedient to keep this distance as small as possible. This is because in that case only an inexpensive detector with a relatively low resolution is needed to measure the angle δ4, which does not need to be highly accurate. If the above-mentioned requirements are not met and the tension shear wire 416 does not accurately determine the reference line to be measured by the angle detector 12B, it may be replaced with one of the tension shear wires. Alternatively, or additionally, a rigid sliding frame can be used.

Measurement light beam γ4. Since the probe ball Tk exists below the plane formed by γ5, a measurement error will occur if the carriage 104 is not guided in the Z direction constantly perpendicular to the plane. Will. Such guide inclinations are caused, for example, by dynamic external forces during movement of the height measuring machine, or due to imperfect flatness of the surface plate 101. On the identification board, the height measuring device 102
This is because it slides on air bearings. A corresponding situation is illustrated in a side view in FIG. 9b.

The error in the position of the exploration sphere Tk in the planes X and Y, which is influenced by the height Z, is caused by the inclination angle indicated by α4. In the illustrated example, the inclination angle α4 is drawn in a vertical plane that includes the 'y axis of the exploration, in order to keep the display as simple as possible. However, it is clear that tilting can occur in any direction and that the component of the tilt angle in the direction perpendicular to the drawing must therefore also be considered.

In an embodiment adapted to perform high-precision measurements, three inductive sensors are installed in the base plate 109 of the height measuring machine 102, as shown in FIGS. Keyer M1. M and M3 are buried, and the keyer measures the distance to the surface of the surface plate 1tll. From the signal of the inductive keyer, the inclination angle α4 or the corrected coordinates X, Y2 which the inclination causes in relation to the position in the planes X, Y are calculated. In addition, the tilt causes a height error Z0, which is influenced by the distance between the Z scale 108 and the probe ball Tk. This correction value also applies to sensor Myu.

It can be calculated using M2 t M3 ft.

The necessary processing calculations of the modified data are performed in calculator 127. This calculator has an inductive keyer M1*M
2 t In addition to the measured value of M3, an interferometer and an angle detector 12
B and the measured value r4+r5s δ42 as obtained from the detector of scale 108 are provided. Since the above-mentioned method for correcting tilt errors assumes that the surface of the surface plate 1010 is flat, the storage section of the calculator 127 also stores two-dimensional information in which all plane deviations are recorded. A modification matrix is stored. Understanding this plane deviation, that is, the topography of the surface plate 1010, is determined in a one-time calibration operation using, for example, an electronic inclinometer.

In the previous embodiments, only an exclusively manual coordinate measuring machine of the invention was described. That is, each coordinate measuring machine was moved by hand on a surface plate. FIG. 10 shows a motor-type measuring device.

The embodiment shown in FIG. 10 essentially corresponds to the manual measuring machine shown in FIG. Since the same parts will not be explained again, reference numbers are not given.

A connecting rod 211 engages on the rear side of the support 203 of the motor-driven measuring machine shown in FIG. This connecting rod 21
1 is moved by a linear drive present in the casing 209 on the carriage 212. The carriage itself has a cross beam 20 between both supports 210 and 220.
8 by means of a second linear drive. Both linear drives move the measuring machine in the planes X and Y.

The connecting rod 211 is engaged at approximately the height of the center of gravity of the height measuring machine. Therefore, the measuring device can be operated quickly without being subject to any disturbing tilting movements.

Based on this drive, which is specifically shown in this example, the table 215 has a large number of specified It is configured as a rotary table or control desk on which it can occupy angular positions ψ.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of the mechanical part of the first embodiment of the coordinate measuring machine of the present invention, and FIG. 2 is a diagram of the second embodiment of the present invention in which changes have been made regarding the link mechanism. 6 is a schematic diagram of the principle of the sixth embodiment of the present invention having two link machines, and FIG. 4 is a schematic diagram of the fourth embodiment of the present invention. FIG. 5 is a schematic diagram of the principle of the fifth preferred embodiment of the present invention. FIG. 6 is a diagram showing the bottom surface of a part of the slide rod 113 in FIG. 5. FIG. 13(7) side view of FIG. 5; FIG. 8a is a detailed vertical view of a light wave interference link mechanism that can be used alternatively with respect to the measuring machine shown in FIGS. 5 and 6; FIG. 8b is a plan view of the link mechanism of FIG. 8a, and FIG. 9a is a plan view of the measuring machine of the type shown in FIGS. 5 to 8.
Fig. 9b is a simple schematic diagram showing the principle of the measuring machine of the type shown in Figs. 5 to 8 from the side; FIG. 1...Surface plate, 2...Height measuring device, 3...Strut, 4
... Carriage, 5... Arm, 6... Lever 7.
...Exploration head, 8...Scale, 9...Pace,
10... Holding plate, 11, 12, 13... Rotating joint,
17... Calculator, 18... Link mechanism, 19...
Exploration ball, 20... Holding member, 21... Rotating joint, 2
2... Guide portion, 23... Rotating joint, 24... Scale, 25... Detection system, 26... Drawer member, 2T... Calculator, 28... Link mechanism, 30...
...Holding member, 32...Linear guide part, 33...Rotary joint, 34...Length scale, 35...Detector, 3
6... Drawer member, 37... Calculator, 38...
Link mechanism, 40... Holding member, 41... School, 42... Linear guide portion, 44... Length scale, 4
5...Detector, 48...Link mechanism, 50...Support, 51...Protruding member, 52°53...Joint, 54...Linear scale, 56...Rod, 58・
... link mechanism, 101 ... surface plate, 102 ... height measuring device, 103 ... support body, 104 ... carrier ...
Holding body, 112... Counterweight, 113...
・Sliding rod, 114... Guide casing, 115...
- Workpiece table, 116... Legs, 117... Workpiece, 119... Graduation grid, 120... Support, 121
...Holding body, 122... Holding body (counterweight), 123... Sliding bale, 124... Guide casing, 128... Angle enocoder, 129... Bearing, 410... Support column, 411... Plate, 412... Rede light source, 413... Measuring light beam, 414... Support plate, 415... Interferometer, 416... Tensile shear,
420... Counterweight, 421... Prism, 422 Reflection prism Fig, 4

Claims (1)

[Claims] 1. The positional coordinates (X, Y) in the plane of the horizontally movable support on the surface plate (101) for the exploration element are arranged at constant mutual spacing (b, L) the rotational position of said support about a vertical axis of rotation (A); δ_4 is detected by an angle detector, and from the known distance (1) between the axis of rotation (A) and the probe element (T_k) and the measured angle (δ_4), the position in the plane is determined. Correction value for coordinates (X_1, Y
_1) is calculated, and the position coordinate (
X, Y) are combined with the correction values (X_1, Y_1), and the vertical coordinate (Z) of the probe element (T_k), which is vertically movable in the support (103), A method for detecting coordinate values of an exploration element, characterized in that the coordinate values are detected by a scale (108) within (103). 2. Inclined position of the support with respect to the vertical line (2) (α_
4) is detected by means of a supplementary measurement means, from the supplementary measurement value and said measured vertical coordinate (2) a second correction value (X_2, Y_2, Z_1) is calculated, and likewise 2. Method according to claim 1, characterized in that the measured position coordinates (X, Y) or the vertical coordinates (Z) are combined. 3. The measurement of the tilted position (α_4) is carried out on the support (1).
3. The method according to claim 2, characterized in that it is carried out by an electronic inclinometer in 03). 4. The measurement of the tilted position (α_4) is performed using the support (1).
03) by at least three spaced apart sensors (M_1, M_2, M_3) in the base (109), which sensors measure the distance to the planar guide of the support. The method according to claim 2, characterized in that: 5. The topography of the planar guide (101) is captured in a separate measurement process and stored as a two-dimensional correction matrix; in order to determine the tilt position, the correction matrix and the 5. Method according to claim 4, characterized in that measurements of the sensors (M_1, M_2, M_3) are used. 6. Method according to claim 1 or 2, characterized in that the position coordinates (X, Y) in the plane are measured by the use of a laser interferometer (415). 7. A vertically movable probe head (7, 107) and a scale (2) for measuring the vertical position of the probe head (2).
8, 108), the probe head (7, 107) is arranged along a plurality of spatial directions. The support carries a probe pin acting as a
Via at least one linkage, at least one fixed reference point (10; 20; 30, 40; 50;
0,120; 210,220), in which case the link mechanism is characterized in that it has a plurality of rotation detectors or scales for measuring the position of the support in the plane. Coordinate measuring machine. 8. The link mechanism (18) has three joints (11, 1
2, 13), and the joint is equipped with a rotation detector (α
, β, γ) are arranged.
Coordinate measuring machine described in. 9. The link mechanism (28) has two joints (21, 2
3) and a pull-out member (26) of variable length (γ_1), and the joint is equipped with a rotation detector (δ_1, δ_2).
), the coordinate measuring machine according to claim 7, wherein a scale (24) is disposed on the pull-out member. 10. The two link mechanisms (38, 48) are each provided with two joints (31, 33; 41, 33) and one drawer member (36, 46) of variable length (γ_2, γ_3). , each of the drawer members is provided with a scale (34, 44), and at least one of the joints (33) is provided with a rotation detector (δ_3). The coordinate measuring machine according to claim 7. 11, one or several link mechanisms (58, 113,
123) is pivotally attached to the upper end of the movable support (2, 102).
The coordinate measuring machine according to any one of the above. 12. Coordinate measuring machine according to claim 11, characterized in that the support (103) is freely rotatable through 360° under one or several slide bars. 13. One or more of the slide rods are engaged with the support (103) by a rotary joint, the vertical axis of rotation (A) of the rotary joint being fixed to the height measuring machine. 12. Coordinate measuring machine according to claim 11, characterized in that the coordinate measuring machine passes through the probe sphere (T_k) of the probe head of the probe head or is at a small distance (1) from the probe sphere (T_k). 14. The support (103) stands upright on a substrate (109) with a large cross-sectional area, and a workpiece table (115) is installed within the movement range of the support, and the workpiece table 7 , characterized in that the substrate ( 109 ) of the support rests on centrally arranged narrow legs ( 116 ) such that the substrate ( 109 ) can pass under the table surface ( 115 ). Coordinate measuring machine described in. 15. The coordinate measuring machine according to claim 14, wherein the fixed reference point is the foot of the workpiece table, and the link mechanism rotatably engages the foot. . 16. Claim 1, characterized in that the linkage (113, 123) is balanced such that it rests essentially without force on the upper surface of the support (103).
1. The coordinate measuring machine according to 1. 17. Both link mechanisms (113, 123) are connected to the support body (1) by two vertical columns (110, 120).
03), and the column is fixed at its upper end by a rigid horizontal bar (118) with a small coefficient of thermal expansion. The coordinate measuring machine according to item 16. 18. Coordinate measuring machine according to claim 17, characterized in that the linkage (113, 123) projects beyond the connection point (A) in the upper part (108) of the support (103). 19. A first drive unit for vertically moving (Z) the probe head and a second drive unit (211) for horizontally moving the support body are installed in the support body (203). The coordinate measuring machine according to claim 7, characterized by: 20, the second drive unit (211) is connected to the support body (2
20. The coordinate measuring machine according to claim 19, wherein the coordinate measuring machine engages the support body at a height of the center of gravity of 03). 21, the second drive unit is configured to support the two pillars (210,
a linear drive part (212) installed on the side of the measurement area of the coordinate measuring machine between 220), the linear drive part itself being connected to a second linear drive part (211
), and a rotary table (215) for the workpiece to be measured is arranged within the movement range of the support (203).
9. The coordinate measuring machine according to 9.