SE465981B - Analogue displacement sensor - Google Patents

Abstract

The invention relates to an analogue sensor with sensing of the deviation from a normal position in at least two directions. The sensor has a ball 52 at the tip of a measuring stick 51, which is spring-mounted in such a manner that it can move essentially about a centre. It is the deviation of the tip as well as its normal position which are indicated. The stick has a sensing part 54, 55 located in a sensing unit in such a manner that the sensing part, in the event of external displacing action on the measurement tip in any direction, can be adjusted from a normal position essentially about a central point CM; CM' and can be returned to the normal position by a force arrangement 53. The adjustment from the normal position about the central point is indicated in order to provide a measure of the deviation. The sensor thus performs angle sensing for displacement force components on the sensor tip, which force components act in a plane which is at right angles to the axis of symmetry of the sensor. <IMAGE>

Description

The invention utilizes the principles of angular sensing described in U.S. 4,521,973 (Wiklund et al) and has further developed and adapted them to be used for a measuring probe.

The essence of the analog sensor according to the invention, which in the manner known per se has sensing for measurements in at least one direction and for this purpose has a ball in the tip of a measuring stick, which is resiliently attached in such a way. that it can move mainly around a center either attached over a spring or a "gimbal" suspended center or is free-floating with returnable to a central position by means of external power, is that one or two electrically which constitute collectors (sensing elements ). Fixed mounted or mounted, mainly symmetrical, opposing elements in the sensitive direction are supplied with alternating voltage. The sensing element or pair of elements detects, through capacitance variations towards permanently mounted elements, the angular change between the output signal isolated but conductive planes are located, the sensing plane and the permanently mounted elements. based on capacitance variation is demodulated phase-clean and filtered. The movable element or elements can without inconvenience change places with the fixed elements, which then means that the movable elements become the driving ones and vice versa.

The invention is described in more detail below with reference to the accompanying drawings, in which Figs. 1A, 1B, 1C show different parts in and an assembly of a first embodiment of the analog sensor according to the invention, Figs. 2A and ZB show an assembly resp. a component in a second embodiment of the analog sensor according to the invention, Figs. 3A and 3B show a compilation of and a schematic sensing connection for a third embodiment of the analog sensor according to the invention, Figs.

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Figs. 4A, 5A, 6A, BA, 9A 465 981 4B, 4C and 4D show an assembly, a pattern plate and two different feed arrangements for a fourth analog sensor according to an embodiment of that invention, and 5B shows a section through the respective schematic winding locations and magnetic field propagations for a first embodiment of a sensor provided with a power sensor, shows an embodiment of a component in a power sensor for the sensor, 7B and 7C show a section through another embodiment of a power sensor for the sensor, a circuit for supplying windings in the power sensor and a top view of the power sensor in Figs. 7A, SB and BC show plan views from different directions of a further embodiment of a power sensor for a sensor according to the invention, and 9B schematically shows a side view of a free-floating sensor with power sensor and a schematic indication of the winding arrangements for the power sensor and the propagation of the magnetic fields in relation to the windings, 10A, 10B, 10C, 10D show different parts in and a circuit diagram of the circuit shown in FIG. 9A and 9B show the embodiment of the sensor according to the invention, shows a block diagram of a control arrangement for an embodiment of the sensor according to the invention, and shows different embodiments of a sensor together with an optical measuring arrangement. 465 981 10 15 20 25 30 35 a measuring ball 2, preferably in sapphire, to which measuring tip is attached in the center of a "plane". circular spring 3, as shown in Figs. 1A and 1B. shown in detail in Fig. 1A, are provided with sub-circular shapes that they give a substantially equal A slightly conical rod 1 with the Spring 3, which are so designed, recesses 4-7, large spring constant in each of -, z-directions measured as force on the measuring tip. Two 4, 5 of the recesses are placed symmetrically about the x-axis and two 6, 7 symmetrically about the y-axis. This leads to a largely isoelastic function (suspension in the direction of normal force), when the ball meets the measuring object. Other types of spring arrangements, which provide isoelastic function than the shown flat spring, are of course conceivable. It is also conceivable to have a gimbal suspension instead. lb, the rod 1 is stably fastened to the center of the spring with two cooperating, interlocking fastening parts B, 9, one on each side of the spring 3. For example, the fastening parts 8, 9 are a bolt and a nut. On the 9 of the fasteners. facing away from the rod 1 is a disc 10 attached. The disc 10 moves as best shown in the figure because it is direct and the disc 10 is preferably a coating of joints with the movements of the rod 1. resiliently connected to the rod 1. and has of electrically non-conductive material electrically conductive material on each side.

A disc 11 of electrically non-conductive material, e.g. a laminate, is stationary attached above the disc 10 and so that it is normally parallel to the disc 10, ie when the rod 1 with the measuring ball 2 is unloaded, ie does not strike any object. The disc 11 is provided with a leading pattern on each side. The pattern facing the disc 10 is shown in solid lines in Fig. 1c, while the pattern facing the disc 10 is shown in broken lines. thus in Fig. 1C up-and-down relative to in Fig. 1b. which is placed on that side, the disc JJ. Example of mounting the arrangement is shown in Fig. 1B. a cup-shaped cover 12 is provided with a lug 13 near its bottom. The disc 11 rests in its upper part in the figure against the lug 10 465 981 13. A ring 14 is inserted in the cover 12 and abuts against the lower part of the disc 11 in the figure. The upper part of the spring 3 abuts against the lower part of the ring 14 in the figure. The axial length of the ring 14 is adapted so that the disc 10 can move for the measuring purpose maximally in the space between the discs 3 and 11. The outer end of the cover 12 is threaded on its inside. A cup-shaped lid 15 with holes for the rod 1 with sufficient diameter for the rod to be able to move freely during movement is threaded on its outside and screwed into the cover 12 and holds the spring 3 in place.

The conductive pattern in Fig. 1C on the underside of the disc 11 (upwards in the figure) is divided into five pattern parts or electrodes A, B, C, D, E of conductive material, four ADs of which are formed as triangular pieces with a removed inner tip and with two straight sides, which intersect near the center of the disc 11 and have the third side extending along a circular path a certain distance from the periphery of the writing. The four parts A-D are evenly distributed and form a pattern which is symmetrical about two orthogonal axes x and y, which intersect the center of the disc 11.

The fifth pattern part or electrode E is designed as a cross with its constraints placed symmetrically between adjacent straight sides of the pattern parts A-D. The dashed pattern part F on the underside of the disc 11 (downwards in Fig. 1C) is annular and lies diametrically outside the pattern parts A-E and has an inwardly extended finger between each space between the straight portions of the pattern parts A-D. The radial fingers on the pattern parts E and F do not necessarily have to be for good function, but they increase the electrode surface and therefore give higher capacitance. each of the parts AF in the conductive patterns serves as a plate or electrode of a capacitor, the second plate or electrode of which is formed by the upper conductive layer of the plate 10 movable with the rod 1. Since the electrode F must co-operate with the upper the conductive coating on the disc 10, it is positioned so that none of the pattern parts AE is shielded between the electrode F and the plate 10.

A465 981 Fig. 1A - 1C shows a variant that works with a single-sided sensing. This variant is best suited for sensing the displacement of the measuring ball only in the x and y directions. An example of the voltage supply of the conductive patterns with the electrodes A-F is shown in Fig. 1C. A voltage vfl with the frequency fl is supplied between the electrodes A and B, which lie along the x-direction.

A voltage vzfl with twice the frequency, i.e. 2 * f1, is supplied between the electrodes C and D along the y-direction. A voltage V4f1 with four times the frequency. ie 4 * fl, can be fed between the electrodes E and F if a deviation also in the z-direction is to be indicated.

Indication of capacitance displacements in three sensing directions x, y and z takes place with a circuit, which is shown very schematically in Fig. 1B. The upper coating on the movable disk 10 is connected to the (+) input of a first operational amplifier OP1. The (-) input of the amplifier OP1 is connected to its output. The lower conductive coating in the figure on the plate 10 forms a capacitor with the upper coating and is bootstrap-connected to the output of the first amplifier 0P1.

The output of the amplifier OP1 is connected to the (-) input of a second amplifier OP2. The amplifier's OP2 (+) input is connected to ground and its output is AC-connected to the amplifier's 0P1 (+) input with a capacitor C1. In addition, a direct voltage feedback is made from the output of the amplifier OP2 to the input of the amplifier OP1 (+) - through a series connection of two resistors R1 and R2, which are common for this purpose, whose connection point is alternately disconnected to ground through a small resistor R3 and and capacitor C2. The housing 12 of the unit is grounded. The output of the amplifier's PP2 is connected to three phase detectors 17, 18 and 19. To each of these is a reference signal with a square voltage. or alternatively triangular or sine voltage, connected. For each one, the sensing interval extends over half a period, which means that the signal for each sense of sensing is demodulated in a phased manner. The output signal from each of the phase detectors is amplified (not shown) and the amplified output signal is in a definite relation to the angular deviation in the direction fed with the same reference frequency as the phase detector in question.

As shown in Figs. 1B and 1C, the pattern parts A and B and C and D form to indicate the movements of the tip 2 in xresp. y-direction with the upper conductive layer of the plate 10 two pairs of capacitors, where the capacitors in each pair change substantially balanced in the opposite direction at an inclination of the plate 10.

The capacitors. formed by the pattern parts E and F intended for the z-direction indication, and the coating of the plate 10 in the same direction. This makes an offset in difficult to indicate safe with that in Fig. 1 but it is mainly suitable as x-y- changes to the z-direction are shown the embodiment, offset sensor.

Figs. 2A and 2B show a second embodiment of the sensor according to the invention. In this embodiment, the conductive electrode pattern A1, B1, C1, D1, E1 is arranged on the disk 22 movable with the rod 20 and placed over the spring 21. Electricity is shown as a star pattern with radially extending parts starting from a central circular, conductive layer. However, the extended parts are not included in order for the arrangement to be able to function in the intended manner, but they provide a larger electrode surface. Fig. ZA does not show the cover for the arrangement with the fastening of the various constituent parts, but this is in principle the same as the one shown in Fig. 1B.

The disk 23 provided with the conductive coating I, the voltage level of which is indicated by being fed to the (-) input of an operational amplifier 25, is in this embodiment fixed and placed opposite the movable disk 22 with the conductive coating facing it. The second conductive coating G1 for the capacitor pair to indicate deviation in the 2-direction fixed disk 24 located Displacement of the sensor is located on a further parallel to the fixed disk 23. The tip in the z-direction is thus sensed by means of two capacitors. of which one G1 / I has constant capacitance and the other El / I has variable capacitance. 465 981 10 15 20 25 30 35 On the opposite side of the disc 23 facing the conductive coating, a ring R with conductive coating is arranged. The ring R is connected to the output of the amplifier 25, whereby the amplifier receives a feedback with a capacitor. formed between the coatings I and R on the disc 23, so that a signal varying about the "0" signal level is obtained at the input of the amplifier 25. In the normal position, the sensor surface I should be electrically approximately in the middle between the G1 and the E1 surface. . The feedback on R gives a lower sensitivity to stray capacitances, since the sensor surface I is then always at ground potential in terms of DC voltage.

As shown in Fig. 2B, in this case the electrodes of the x and y-displacement capacitors are supplied with the same frequency f2 but with a mutual phase shift of 90 °, i.e. they are supplied with the respective voltages vfz oo and Vfz 90 ,. The electrodes for the z-position capacitors are supplied with a voltage with twice the frequency, ie Vzfz. It should be noted that it is within the scope of the invention to instead supply the z-electrode pair with a voltage with half the frequency fz or with some other multiple n of f2. Other variants with three frequencies for each x, y and 2 instead of two, where 0 ° and 90 ° are used on one, are of course also conceivable.

The output signal from the amplifier 25 is signal processed in a manner similar to that indicated in the embodiment shown in Figs. 1A-1C. The output signals x, y, z are in this case simply filtered, analog measurement signals, which in a known manner can be converted into digital values for sampling and data processing in a connected measuring computer. The type of feed shown here can also alternatively be performed on the embodiment according to Figs. 1A - 1C, as well as the type of feed shown therein can be used in the embodiment according to Figs. 2A, 2B.

Fig. 3A shows an embodiment of a measuring probe according to the invention, which is symmetrical about the center of motion CM of the probe and which has balanced capacitance pairs for displacement indication in all three directions x, y and 2. Nor in \ o |. 465 981 This figure shows the fastening arrangements for the stationary units, which are the spring 30 with substantially the same design as the spring 3 in Fig. 1a and the outer discs 31 and 32. The middle discs 33 and 34 are rigidly connected to the rod 35 with the tip 36 and movable therewith in the directions x, y, z around the center of movement CM. Each of the movable discs 33 and 34 is provided on its side facing away from the springs 30 with a pattern which may have the design shown in Fig. Zb except that the electrode E1 is provided with a hole in the middle. This hole is due to the fact that the rod 35 must be attached to the fastening units on the spring 30 and that the patterns on both discs 33 and 34 must be exactly the same.

The mutually corresponding pattern parts for indicating the deviations from A1, B1, C1, D1 in Fig. ZB on the discs 33 and 34 are interconnected. 3A shows the pattern parts in the x and y directions, corresponding to the pattern parts, with each other, so that e.g. . those in fig.

C1 'and C1 "are interconnected, as are the pattern parts D1' and D1". Note that the pattern parts of the same type on the discs 33 and 34 are diametrically relative to each other, so that an offset in some direction acts in the same direction for the supply capacitors on each side of the spring 30. Assuming that the supply of the electrode plates for indicating deviation in x and the y-direction is the same as in 2B, for indicating deviation in the z-direction one is fed to the primary side of a transformer, whose grounded central socket is connected between the pattern- fig. voltage vzfz secondary side with the parts E2 'and E2 ".

Each of the outer plates 31 and 32 has on its side facing the movable plates three annular coatings, of which the radially middle 37 and 40 is widest and is connected to the (+) input of an operational amplifier OP3 such as the sensing electrode (see Fig. 3B). The OP3 of the amplifier's output is connected to its (-) input. 42 annular 45 on the outer 38 resp. 41 and the inner 39 resp. the coating as well as a comprehensive coating 44 resp. 465 981 10 15 20 25 30 35 40 10 the two disks 31 and 32 are connected and bootstrap-connected to the OP3 output is connected to the (-) input of the OP3 output of the operational pre-operational amplifier. The amplifier's amplifier OP4, whose (+) input is connected to ground. The output of the amplifier OP4 is fed back to the amplifier's OP3 (+) - input partly with a capacitor and partly with a direct voltage feedback without alternating voltage feedback of the same type as that shown in Fig. 1B.

In addition, the output of the amplifier OP4 is connected to three phase detectors 46, 47, 48 of the same type per se as in Fig. 2A of the offsets in the three sensing directions. The low-pass filtered outputs from the phase detectors 46, 47, 48 are then, after analog-to-digital conversion in, each analog / digital converter A / D connected to the input of a microprocessor 49 with peripheral equipment, which is provided with one in the sensing directions with the phase detection as program memory and working memory, programs, which calculate the deviations and leave them at one or more outputs for connection to such as e.g. a presentation unit or which utilizes the obtained signals other equipment, any utilization unit, as control signals e.d. (not shown).

Fig. 4A, 4B. 4C, 4D show a fourth embodiment of the device according to the invention. This embodiment is the preferred one.

In the perspective view in Fig. 4A, for the sake of clarity, the input sensor elements are placed further apart than in reality.

The sensor rod 51 with its sensor ball 52 is suspended in a spring 53, so that the suspension point is centrally fixed with the possibility of movement in the 2-direction (along the rod) and mobility of the shaft axis rotationally symmetrically at an angle to the 2-axis with retained attachment point perpendicular against the shaft of the rod. as shown in the previous embodiments.

On the rod, isolated from it, a pair of electrically conductive collector plates 54 and 55 are fixedly mounted on each side of the spring 53. The collector plates are suitably of metal and are electrically connected to the spring 53. 10 15 20 25 30 35 465 981 ll Sondens housing is not shown but may be of the same type as it. shown in fig. 1B. The spring 53 has peripheral outer tongues 56, 57, with which it is attached to the housing.

Axially on each side of the collector plates 54 and 55 are a pair of drive plates 58 and 59 fixed in the probe housing, which are printed circuit board plates with conductive pattern parts on a substrate.

The pattern on the printed circuit boards is shown in fig. 4B and schematically also in fig. 4A. The pattern on the pattern discs 58 and 59 is equal and the patterned surfaces on the discs face the collector plates 54 and 55. Equal pattern parts on the discs 58 and 59 are fed in the same way, whereby from the spectator seen front pattern parts e.g. the disc 58 corresponds to rear pattern parts eg c2 'of the disc 59 and left pattern parts e.g. dl of the disc 58 corresponds to right pattern parts d2 of the disc 59 and vice versa (cf. Fig. 3A). 4B, the pattern parts on the disc 59 are indicated. These are In the innermost ring is an I fíg. placed in concentric rings. fan blade-like pattern part b 'for indicating movement i as shown in fig. 4c, a voltage is supplied between the pattern part b on the disc 58 and the signal shape can, as mentioned, be placed in the z-direction. with the frequency n * fo the pattern part b'on the disc 59. above be a sine or some kind of edge wave. All the radially projecting parts of the pattern b 'are interconnected by one are located between the projecting are connected to the inner ring of the disc 59. Pattern parts a 'the parts in pattern b'. The pattern parts a 'each other on the back of the board. The pattern parts a 'together with the collector plate 55 and the pattern parts a on the disc 58 together with the collector plate 54 form a feedback capacitor for the one in fig. 4A showed the circuit.

The ring outside the innermost has the pattern parts c2, c2 'and d2, d2' for indicating the movement of the measuring ball in the x-respective y-direction. An alternating voltage is supplied with the frequency fo and the phase 0 ° between the pattern parts d2 and d2 ', as well as between the pattern parts d1 and d1' on the disc 58. In addition, an alternating voltage with the frequency fo and the phase 90 ° is supplied between the pattern parts c2 and 465 981. C2 ', as well as between the pattern parts c1 and c1' on the disc 58.

Fig. 4c shows that this supply can take place via transformers, as described above.

Fig. 4D shows an alternative method for generating the drive signals. A frequency divider 62 is supplied with a signal with the frequency 4 * fO. the flip-flop 62 has an output Q1 with a signal with the frequency 2 * f and another output Q2 with a signal with the frequency f and the phase 0 °. the output of the flip-flop 62 Q1 is connected to a first amplifier 63 with an inverted and an inverted output, one of which is connected to the pattern part b and the other to the pattern part b '. the Q2 output of flip-flop 62 is connected to a second amplifier 64 with an inverted and an inverted output. one of which is connected to the pattern parts d1 and dz and the other to the pattern parts d1 'and d2'. The outputs Q1 and Q2 are also connected to their respective inputs on an EXELLER gate 65, at the output of which there is then a signal with the frequency f, which is 90 ° phase-shifted in relation to the signal on the output Q2.

This signal is supplied to a third amplifier 66 with a right-facing and an inverted output, one of which is connected to the pattern parts c1 and c2 and the other to the pattern parts c1 'and c2'.

A protective ring r 'on the disc 59 resp. r on the disc 59 are located radially at the outermost and years connected to the probe housing.

The collector plates 54 and 55 are electrically connected to the spring 53. and the signal is suitably taken out via the spring 53 isolated from the probe housing. The collector signal is fed to the (+) input of an operational amplifier 60. whose (-) input is connected to its output. To eliminate short-circuiting scattering capacities around the collector plates, the surrounding probe housing, together with the protective rings r and r '. Bootstrap connected to the amplifier's 60 output. The output of the amplifier 60 is connected to the (-) input of an operational amplifier 61, the output is connected to phase demodulation circuits (not shown) for separating information regarding movement in the x, y and z directions, VQIB in the same manner as described for the above 10 Described embodiments. The pattern parts a and a 'are connected to the output of the amplifier 61, whereby alternating current feedback takes place through a composite capacitor between the parts a and the collector 55 and the collector 54.

DC feedback takes place in the same way as described for and between the parts a 'of the above-described embodiments.

To make the measuring tip quickly movable, a simple power sensor can The power sensor's drive system must then By being connected to the sensor. act on the ball of the measuring rod in the x, y and z direction. combining the capacitive sensor with an inductive power supply, a single combination unit could easily be produced.

However, a certain reduction in the measurement accuracy is obtained with such an arrangement, since power and measurement take place in conjunction, but the advantage of rapid mobility outweighs in most cases. Possibility to switch off the power supply part. with a switch can be arranged.

An inductive power sensor coupled to a capacitive sensor of the type shown in Fig. 4A is shown in Fig. 5A. However, it is obvious that any of the shown embodiments of sensors can be used here. The collector plates 71 and 72 are rigid, electrically connected together with the spring 73. The spring 73 is electrically insulated with insulating rings 74 and 75 between two annular holding elements 76 and 77. The pattern plates 78 and 79 are inserted in grooves in each of the holding elements 76 resp. 77, which are preferably of metal and Bootstrap-coupled to the output of amplifier 60 (see Fig. 4A).

The rod 80 with the measuring ball (not shown) rigidly connected to the capacitor plates 71 and 72 extends through the unit 71-73 with an additional part 81, which is attached to a power sensor.

The force sensor according to Fig. 5A comprises a cup-shaped part 82 made of insulating material with the opening 'facing away from the sensor and provided with an annular curved, projecting, disc-shaped collar 83. 465 981 10 15 20 25 30 35 40 14 The center of curvature of the collar 83 is located approximately at the sensor's motion center CM '. Both sides of the cup-shaped part 82 are provided with a loudspeaker winding 84 and the collar 83 is provided with windings L1-L4. The whole unit 82, 83 is movable and fixed magnetic fields cross the windings. The arcuate portion 82 with its winding 84 acts as a speaker coil.

The four windings L1, L2. L3, L4 are arranged in a square (see Fig. SB) on the annular laminate sheet 83. so that four are formed, which are placed, two L1, L3 along the x-axis and two L2, L4 along the y = axis. The windings in or on the laminate are achieved, for example, in multilayer technology (wound) The magnetic field extension M1, embossed poles or by the "square" coils being compressed into a laminate form. M2, M3, M4 laterally of the vertical magnetic fields through the disc 83 are shown in Fig. 5B and lie obliquely with respect to the coils L1 - L4, further into the field if the direction of mangetization is opposite to and cast in whereby a current-carrying coil tends to be drawn and repelled otherwise.

The approximately vertical and horizontal magnetic fields shown in Fig. 5A are provided by an arrangement of permanent magnets and soft iron elements. A rod-shaped permanent magnet 86 is placed in the opening of the cup-shaped part 83 above the winding 84. Soft-magnetic. rod-shaped parts 87 and 88 are fixed on each side of the magnet 86. An annular unit 89 provided with four permanent magnets with the magnetization transverse to the axis of the rod 80, when in its normal position, is placed around the soft magnetic rod 88. An annular pole shoe 90 with at least soft magnetic parts adjacent to the permanent magnets is placed around the ring 89. Another ring 91. with soft magnetic parts is placed opposite the ring 90 on the other side of the collar 83. The surfaces facing the collar on the rings 90 and. 91 has essentially the same curved shape as this one. The collar 83 is in its normal position parallel to these surfaces. The magnetic lines are drawn in the left part of fig.

SA. The sensor part is insulated from the power sensor part, in that the stationary soft iron ring 91 of the power sensor part is placed in an inner recess in an annular insulating housing part 92 glued to the holding element 76.

H11 '10 15 20 25 30 35 465 981 15 By feeding the coils L1-L4 and 84 with suitable signals, the movement of the measuring rod can be controlled in the x-, y- and z-direction as desired.

By drawing current in the x-coils L1, L3 or the y-coils L2, L4, a force in the corresponding direction is obtained. The z-coil 84 is a variant of the speaker coil for generating power in the z-direction.

Current supply of each individual coil can e.g. take place as soon as the output signal from the microprocessor 49 in FIG. BB is obtained. which indicate the direction in which the coil is intended to provide power. However, the power sensor is preferably used to provide a preset for the measuring ball during a measuring process, which will be described in more detail below. deviation Many variants of coils and laminates are conceivable to provide the same function as the power sensor in fig. 5A. Fig. 6 shows an example of a cage winding arrangement wound on a spool body 100, which provides x-, y-, z-force directly in front of the spool body, so that the laminate collar 83 with spools is not needed. The magnetic arrangement can then for instance consist of an inner cylinder provided with permanent magnets and an outer ring provided with permanent magnets with connecting soft magnetic pole shoe above the coil body 100 (not shown), so arranged that relatively narrow magnetic fields 103, 104, 105 extends through the body 100.

In the embodiment shown, the cage winding arrangement comprises four spiral windings 101 and 102 (only two can be seen in the figure) for power supply in the x and y directions evenly distributed around the circumference of the coil body and at the same level. They are positioned so that the magnetic field lines through the coil body, which have the relatively small lateral propagation indicated by the surfaces 103, 104, 105, are evenly distributed between each of the two helical windings 101, 102.

When extra force is to be given in the y-direction e.g. to the right in the windings 101 and 102 with current in such the figure are fed 465 981 10 15 20 25 30 35 16 directions that one coil gives attraction to be inserted further into the magnetic field 103 and the other gives repelling from the magnetic field. the same type of feed is made in the windings on the other side of the coil body 100, so that no movement takes place in the direction of the magnetic field. When power is to be given in the x-direction, i.e. in the direction transverse to the plane of the paper, the winding 102 and the winding (not shown) placed next to it on the other side of the spool body are fed with current of such directions that one tends to be pulled into the magnetic field 105 and the other is repelled. The same type of current supply is made for the winding 101 and its winding adjacent to the coil body next to it and then of course so that the power supply takes place in the same direction along the x-axis.

In addition, spiral windings 106 are located at a level above the windings 101, 102, so that their lower part is hit by the magnetic fields 103, in order to provide force in the z-direction. The windings 106 only need to be two. as in the figure, one on each side of the spool body 100, but they can also be several, e.g. four symmetrically placed around the spool body. The important thing here is that the windings 106 are slightly offset in relation to the magnetic field passage 103, so that they can also alternatively or additionally be located at a level below the windings 101. 102. in the case of additional upward force, the windings 106 are fed with a current of one current direction, which provides repelling in the magnetic field 103, and in the magnetic field opposite to it on the other side of the coil body 100 and in the case of additional downward force with a current with a current direction which gives attraction.

Figs. 7A, 7B and 7C show a further embodiment of a power sensor for the sensor, where a cup-shaped part 110 provided with windings has its cylindrical part 111 provided with four windings L1 ', L2'. L3 ', L4'. The part 111 has its bottom upwards and its opening downwards in the figure. The rod connected to the sensor part (not shown) thus extends centrally through the part 111 and is fixed in the bottom 110 with a screw connection 113.

A double magnet-equipped cylinder has an inner cylinder part 114 I? dl 10 15 20 25 30 35 465 981 17 and an outer cylinder part 115, which parts are located on each side of the cylindrical part 110 of the cup-shaped part 110. The inner cylinder 114 comprises a cylindrical permanent magnet 116, which in the axial direction is surrounded by two annular pole shoes 117, The outer cylinder 115 comprises a cylindrical permanent magnet 119, direction is surrounded by two annular pole shoes 120, soft iron. The axially polarized magnets 116 and 119 are pole-facing in the opposite direction, so that magnetic lines between their respective south poles will by means extend substantially across the air gap through diametrically opposite winding portions of the windings L1 '- L4'. The magnetized cylinders 114 and 115 are held by a holder 122, which is screwed into the housing of the sensor part and which provides insulation between the sensor part and the drive system. The holder is provided with a central hole with the same diameter as the inner diameter of the magnetic cylinder 114. This diameter is substantially larger than the diameter of the rod 112, so that it can move freely under the influence of the drive system and of As in all the embodiments shown 118 of soft iron. axial 121 of which in the north and of the pole shoes displacements of the measuring ball. The forms of the invention are the rod of electrically insulating material, e.g. of ceramics.

Fig. 7B shows a circuit diagram for operating the drive unit of Fig. 7A. Signals for the desired tuning in the x, y and z directions are connected to respective amplifiers F1, F2 and F3.

The output signal from the amplifier F1, to which the x-signal is applied, is supplied partly via a first adder A1 to another amplifier F4 and partly via an inverter 11 and a second adder A2 to an amplifier F5 matched with the amplifier F4. The signal for tuning in the x-direction is fed from the amplifier F4 to the winding L1 'and from the amplifier F5 to the winding L2', whereby these windings are driven in opposite directions so that their movements in the magnetic fields from the magnetic cylinders in the x-direction interact with each other. 465 981 10 15 20 25 30 35 18 The output signal from the amplifier F2, to which the y-signal is applied, is supplied partly via an adder A3 to another amplifier F6 and partly via an inverter I2 and another adder A4 to an amplifier F7 matched with the amplifier F6.

The signal for tuning in the y-direction is fed from the amplifier F6 to the winding L3 'and from the amplifier F7 to the winding L4', whereby these windings are driven in opposite directions so that their movements in the y-direction in the magnetic fields from the magnetic cylinders interact with each other.

The output signal from the amplifier F3, to which the z-signal is applied. fed to the four adders A1, A2, A3 and A4. The four L2 ', L3' and L4 'clays, which drive the windings in the same direction in the 2-direction, so that they are not waved in these directions by the' x signals ', the windings L1', are then fed with the z-signal without instead, it tends to pull more in or out of and thus shift up or down in Fig. 7A. The windings are supplied with the signals from the circuit of Fig. 7A in the terminals P1, P2, P3 and P4 to the respective windings L1 ', L2', L3 'and L4'. the magnetic fields between the magnetic cylinders Fig. 8A, BB. 8C shows an embodiment of a sensor with power - where the elements for both the sensor and the power sensor are ie the sensor and power sensor, jointly placed on the same discs, two mechanically rigidly connected separate sensors are not units.

The sensor part may, for example, electronically have the design described in connection with Figs. 4A - 4D. The wiring patterns shown on plates 58 and 59 in Fig. 4A. are then placed on the 131 and 132 and the collector plates 54 and 55 in Fig. 4A as conductive layers 136 and 136, respectively. 137 on the movable plates 133 and 134 fixedly connected to the measuring rod 135, placed on each side of the spring 139.

The wiring patterns and collector layers are here on a central stationary plate portion of the discs, so that the periphery is left free. 10 15 20 25 30 35 465 981 19 The active part of the force part is placed on the periphery of the discs and consists of an annular, placed on a 133 of the movable discs. laterally magnetized, eight-pole magnetic unit 138, as shown in Figs. BB and BC.

On the stationary disks 131 and 132, preferably on the opposite side to the drive pattern of the sensor, are windings having substantially the configuration shown in Fig. 8B. placed. In the figure, for the sake of clarity, only one winding turn is shown for each winding part, but it is obvious that each winding part can have several turns. The lines of force for the magnet and the winding arrangement are shown in Fig. BC. Depending on the control of the windings on each side of the magnet unit 138, movement can be maintained in the three Cartesian coordinate directions. It is obvious that ring magnets can instead be placed on the stationary discs 131 and 132 and the windings in that case are placed on the discs 133 and 134.

The sensor circuits for the sensor part and the control circuits for the power part are suitably located on a stationary control line plane 140.

Fig. 9A shows an embodiment with both sensor and force sensor but with only a movable laminate plate 150. This provides a free-floating measuring system with sensor and force sensor in one laminate. The laminate plate is thus not attached to a spring float by means of the power system. 9A is symmetrical about a power sensor arrangement system without it holding the displacement sensor of FIG. Central point CM 'in the center of the disk 150. have coils 151, 152 on each outside of the plate 150 formed in the manner shown in Fig. 9B. On each side of the disk 150 are two stationary magnetic disks 153. 154 of e.g. BaFe placed, magnetized along its circumference with alternating south and north poles, two of each, and cooperating with the coils. coils existing coil arrangement LA1-LA4 which provide mutually different magnetic fields. When each of two is supplied with current, power is provided in x or y direction, and when they are supplied 465 981 10 15 20 25 30 35 20 with current, which for coils placed next to each other each other in the magnetic field from the magnetic pairs give the same direction on their magnetic field, power is given in the z-direction and so that they give attraction or repelling to nearby magnets depending on the direction in which the power is to be given.

By making the laminate or board with cast coils relatively thick and utilizing the horizontal magnetic field between the poles through the laminate, two power generations can thus be obtained. You can then e.g. give force in the x / y direction at the upper part of the disc 150 and in the .z direction 'at its lower part. Three coil systems provide three degrees of freedom according to Figs. 9A and 9B (two areas on the top of the disc provide power in y and x, respectively, and four areas on its underside in z). the rod 155 with its measuring tip is fixed in the laminate disc 150, which is of course free-floatingly arranged between the stationary magnetic discs 153. 154.

On each side of the disk 150, between the disk 150 and each of the magnetic disks 153, 154, is a stationary disk 156 and 156, respectively. 157 placed. In this embodiment, the sensor capacitors have their different electrodes placed partly on the discs 156 and 157 and partly at different levels 158, 159, 160 inside the disc 150. The different electrodes are preferably placed so that they are not significantly affected by the electric and magnetic fields of the power sensor arrangement. . In the embodiment shown, the power arrangement is located centrally and the sensor arrangement radially outside it.

An embodiment of the electrode arrangement of the sensor part is shown in Figs. 10A, 10B, 100 and 10D which shows an embodiment in which six quantities are measured, namely translational movement in x, y and z and rotation qx, qy and qz about the respective coordinate axes. Fig. 10A shows a quarter of the electrode plate arrangement in perspective. The electrode plates 165 - 158, which are supplied with alternating voltage, are placed on the stationary disks 156 and 157 in Fig. 9A. As shown in the upper part of Fig. 10D, the electrode plates 169, 170, which serve as sensing electrodes, are connected and connected to the (-) input of an operational amplifier 171. inside the movable disk 150 directly below each other at the different levels 158 and 159 (Fig. 9A). In a center plane 160 of the disk 150, a further electrode disk 172 is placed, which may be annular and which is connected to the output of the amplifier 171 to provide a feedback capacitance.

The plates 165, 166, 167, 168 in the sensor are supplied in accordance with what is shown in Fig. 10B and 1OD (top) is supplied with an alternating voltage in relation to earth. where the alternating voltage of the different plates is 90 ° phase-shifted relative to each other. i.e. 0 °, 90 °, 1B0 °, 270 °. In this case, the rash on the detector plates according to Fig. 10C is obtained. thus sensitivity in two directions by detecting phase purity at 45 ° and 135 °, as shown in Fig. 10D, and as shown in Fig. 10C, which shows a direction diagram for sensing.

Two opposite arrangements of the type shown in Fig. 10A give deviation in the x-direction and two opposite arrangements perpendicular to these give deviation in the y-direction. All four arrangements are fed separately, as shown by the four circuits in Fig. 10D. Here you can choose to either have the same frequency of the circuits' supply voltages or mutually different supply voltages. As shown in the upper circuit of Fig. 10D, demodulation with reference signal with square wave with 90 "mutual phase shift (45 ° and 135 °, respectively) to the phase detectors 173 and 174 connected to the output of the operational amplifier 171 takes place in the same manner as described above. . The signals from the phase detectors are fed through separate buffer amplifiers Bul and Bu2. If now the circuit shown in Fig. 10D is connected to an electrode plate arrangement for indicating x-direction, the output signal U1 from the signal with phase shift signal 0 ° indicates movement perpendicular to the x-direction, i.e. in the z-direction, while the second output signal U2 indicates movement in the x-direction. 465 981 10 15 20 25 30 35 22 In Fig. 10D the four motion indicating circuits are shown below each other. As mentioned above, with the arrangement shown in this embodiment, six different deviations from a normal position must be indicated. As shown in Fig. 1OD, eight views are obtained, which directly or in combination with each other give a definite result, which does not exactly mean any disadvantage. rotation nals, the different deviations ,, means that the system becomes over the y-axis is obtained by utilizing the difference between the output signals 2 and. z rotation about the x-axis by A B 'utilizing the difference between the output signals zc and 2D and rotation about the 2-axis by combining XA, xB, yA and yB. Pure motion in the x-direction of either x or A xB and in the y-direction of either yA or yB and in the 2-direction of any of 2 - z If the deviation from. the normal mode is a mixture of different directions and rotations, the calculations of the different deviation components become relatively complicated. The output signals from the circuits in Fig. 10D are therefore fed to a computer presenting the six obtainable quantities. (not shown), which performs the calculations and In a measuring machine with a moving measuring probe, one of the problems is to obtain a high measuring speed and still have one. high accuracy. It is important to stop the measuring beam movement in as central a position as possible in relation to the measuring probe's central sensing area.

This can be done either by low speed of the measuring beam or to allow higher speed and have return (overshoot), ie reversing of the measuring beam. after it has passed out of the current measuring range to obtain high measuring accuracy. The dynamic forces mean that short braking distances interfere with the measurement accuracy.

In most cases, however, the speed cannot be selected higher than a certain top speed for safety reasons.

By using this power sensor in a probe with its own power sensor to provide a setting function, where the position can be determined 10 15 20 25 30 35 465 981 23 to the direction and size, the probe's measuring tip (maximum) can be displaced in the forward direction in the direction of movement. allow a higher measuring speed than before while avoiding reversing the measuring beam and the safety aspects are met.

The processor 180 in Fig. 11 may in such a case have an input connected to a unit 185, affecting the direction of movement of the measuring beam. things are fed with a program via it. external control unit 181 or, if this possibility is to be permanently built into the probe, be provided from the beginning with a software which calculates the current AX, AY, A2. which are to be fed to the respective transducers of the power sensor in order to expose the tip of the probe with advance in the direction of movement so offset that the braking distance is in principle doubled for "emergency stop". The maximum speed can then be doubled at constant braking force, ie you get approximately double the braking distance. For measuring purposes, since the stop point is in principle known, the speed can be selected maximum-adapted for braking distance to "0" position or so adapted that the measurement takes place at a certain constant speed. when the "0" position is passed and the smallest error in the output signal of the analog measuring probe is present.

All this is calculated by the processor 180 using the appropriate software. then, of course, in addition to the current supply AX, AY, AZ to the windings of the power sensor, also controls a control unit 186 for the measuring beam. The control unit can be provided which gives the measuring beam varied speed in the different directions according to the circumstances. As soon as the measuring probe encounters an obstacle in the direction of movement, this is indicated by a change of one or more of the input signals x, y, z to the microprocessor 180, which calculates the suitable output signal to the unit 186 and suitable output signals AX, Ay, A2 for measuring - the beam shall come to a standstill in the vicinity of the sensed obstacle and the probe when it has reached there shall be set in PIOCQBSOEH with signals, its normal position. i4e5 981 10 15 20 25 30 35 24 If the position and appearance of the measuring object is known in principle, the measuring beam can be controlled to move at a high speed to a position near the object and from there controlled to move at a speed which is so adapted that the measuring beam can be controlled to a standstill from the moment the probe encounters the measuring object on a distance corresponding to the deflection of the probe in the direction of movement. The power sensor is then also controlled to assume a neutral position for the probe.

Since it is possible to exhibit the measuring probe in any direction, this can be used for special types of measurements. The processor 180 allows different types of calculations to control the probe's sensor and this can of course be utilized by inputting different types of software into the processor from the unit 181.

One can e.g. lower the probe into a hole and measure the shape of the hole by controlling the exposition of it in a rotating motion and sensing with the sensing part of the probe at which exposing angles in different horizontal positions the tip of the probe makes contact with the walls of the hole.

A sensor can be provided with feedback via the power sensor with such properties that it has great resistance in one direction, e.g. X-direction, but is soft in another direction, e.g. the y-direction. This is accomplished by returning the x-measurement signal with a negative sign to the x-power sensor while returning the y-measurement signal with a positive sign or not at all. This feature is valuable in case you need to scan a probe over a surface along given lines. Of course, it is also possible to have varying counterforce soid) by having mutually different degrees of feedback in the x, y and 2 directions. The degree of feedback can also be varied according to the degree of deviation from the normal position, so that knowledge of the position is used as a gain correction in the current amplifier to the power sensor. The elasticity can also be compensated for by non-linearity of the return spring 30 (see Fig. 3A) or the spring arrangement by calculation in the processor. The various computer programs and algorithms for achieving the above-mentioned controls are banal. to achieve for a programmer on the basis of the given data and is therefore not described in more detail.Compensation can be achieved, for example, by performing comparative measurements against a reference probe and storing the resulting compensation values in a fixed memory.

There is a type of known optical measuring machines, which measure against that which moves laterally, focuses in This is the principle for, for example, VIDICOM marketed by OGP. The disadvantage of this type of measuring machine is that there is no possibility of mechanical measurement. some machines are therefore made to be fitted with a probe in the z-axis. which provides a good solution (combination machines). an X.Y board. wherein the optics z-direction.

Fig. 12 shows a use of a probe according to the invention together with an optical measuring device, which examines the distance to an x, y measuring table 190 by focusing with a lens 192 mo xy - the table a beam from a simple laser distance meter 191 with simple focus adjustment of the type found in some cameras. For focusing, the edge rays in the light package are needed above all, which give a better, ie sharper, focus than the low-angle, central rays. The focus is adjusted by means of a lens holder part 191 ', which is movable in the 2-direction.

According to an additional embodiment of the invention, the focusing lens 192 can then be provided with a central through hole 193, and a probe 194 of the type described above is placed so that its rod 195 with measuring tip 196 passes through the hole 193. Thereby the probe 194 becomes completely centrally located in the optical measuring device without obscuring the focus. The probe can then be lowered to provide mechanical measurement of the object which accurately gives the laser distance meter (not shown), to a distance determinable by means of a drive unit in relation to 465 981 10 15 20 25 30 35 26 193. Such drives are well known in the art and need therefore not described in more detail. Since the distance between the measuring tip 197 and the probe head 195 as well as between the probe head 195 and the distance meter head 193 are known, the focusing point can be determined accurately with the mechanical measurement and adjustment of the focusing point takes place extremely accurately, when mechanical measurement takes place The measurement result can also be used to calibrate the optical distance meter, whereby subsequent non-contact measurement with only the optical unit 193 and the mechanical probe in the raised position has increased accuracy.

The combination arrangement with an optical measuring device can be carried out in a number of variants. Fig. 13 shows the head 197 of the probe placed outside the light beam from the unit 191 and provided with a curved measuring rod 198, which connects to the part 195 'of the rod with the measuring ball 196' running along the central hole 193 in the lens.

Fig. 14 shows a probe head 199 placed next to the optical measuring arrangement with a curved sensing rod 200 with an axial part 195 "with measuring ball 196" placed under the lens.

Fig. 15 shows that the probe head 201 placed on the side can also be connected to the measuring ball 203 with an inclined and deflected rod 202. The inclined rod can also have the measuring ball directly on its end (not shown).

Many modifications are possible within the scope of the invention.

For the power sensor, it is also possible to use the drive system as a dynamic damping device for the measuring rod by having short-circuited coils. For this purpose, a conductive cylinder may be mechanically connected to the movable rod and placed in a magnetic field. Different feed frequencies but in different phases can e.g. can be used to supply the different capacitors also for indicating the same direction.

Claims (24)

10 15 20 25 30 465 981 27 Patent claims An analog sensor with sensing deviation from a normal position in at least two directions, which sensor comprises a mechanical sensing unit (1,2,8,9,10; 35,36,33,34; 51,52,58,59 ) with a measuring tip (2; 36; 52), the deviation of which from its normal position must be indicated, characterized in that the measuring tip (2; 36; 52) is attached to one end of a rod (1; 20; 35; 51; 80), which has a sensing part (8.9; 54.55; 71.72) placed in the sensing unit, in such a way that the sensing part is externally displaceable in any direction from a normal position in the event of an external displacement around a central point (CM; CM ') and returnable to the normal position with a power device (3; 21; 30; 53; 73; FIGS. 7A-7C, FIG. 9A, 9B), and that the displacement from the normal position around the central point is indicated to provide a measure of the deviation, whereby the sensor performs angular sensing for displacement force components on the sensor tip, which force components act in a plane which is perpendicular to the symmetry of the sensor - shoulder. 2. An analog sensor according to claim 1, characterized in that the sensing part is attached to a resilient force device. 3. An analogous sensor according to claim 1, characterized in that the sensing part is suspended in a free-floating manner and the power device is arranged to return it to the normal position with magnetic action (Fig. 9A). 4. An analogous sensor according to any one of the preceding claims, characterized in that the sensor is arranged to make a linear sensing for a shear force component which acts on the measuring tip axially with respect to the sensor. 465 981 10 15 20 25 30 35 28 An analog sensor according to any one of the preceding claims, characterized by a holder arrangement (3,8,9; 30; s3; 151,1s2,1s3,1s4) for the sensing unit so arranged that the sensing unit is displaceable and returnable substantially around a central point, a movement unit rigidly connected to the sensing unit (10; 33.34; 58.59; 150) provided with at least one first electrode plate (D1, C1, E1; 54.55; 169.170) for a capacitive element, a stationary arrangement (11; 31.32; 58.59; 156.157) provided with at least one second electrode plate (AF; 44, 37, 38, 39, 40, 41, 42, 45; a, b, c1, c1). ', d1, d1', a ', b', c2, c2 ', d2, d2'; l65-168) for a capacitive element located near the motion unit, that at least one variable capacitor comprising said at least one electrode plate on the motion unit and said at least an electrode plate on the stationary arrangement are arranged at least for the first two directions to be indicated, that for each direction to be indicated there are at least two capacitors, of which at least one consists of said at least one variable capacitor, wherein at least two of the capacitors are supply capacitors and supplied with respective alternating voltages phase-shifted to each other, and the supply capacitors are in a normal relationship to each other without affecting the measuring tip, which ratio changes - landslide when displacing the measuring tip, and that at least one sensing electrode unit (I; 37,40; 54,55; 169,170) common to all sensing directions, for which deviation is to be indicated, is arranged as one electrode of the supply capacitors; and for each electrode pair, the value difference between the capacitors in the pair is indicated by the fact that for each sensing direction an output signal taken from the sensing electrode unit is demodulated in a pure phase in an individual phase detector (17, 18, 19; 46, 47, 29). 48; Fig. 10D), and that the demodulated output signal from each phase detector is in a certain relation to the deviation of the bearing location from the normal position in the direction in question. Sensor according to claim 5, characterized in that a pair of capacitors are arranged for each direction of said electrode plates on the movement unit and electrode plates on the stationary arrangement, that for each indication direction both capacitors in the pair are supply capacitors, and that the supply capacitors are fed with each their alternating voltage with the same frequency, which alternating voltages are in opposite phase to each other, whereby a given combination of impedance and alternating voltage for the two capacitors in the pair is equal in the normal position and the capacitors change their values in opposite directions when shifting from the normal position along the sensing direction for the couple. Sensor according to one of Claims 2, 4-6, characterized in that the holder arrangement comprises a spring (3) with an isoelastic function. Sensor according to one of Claims 5 to 7, characterized in that two pairs of capacitor combinations are arranged to indicate deviation from the normal position in two directions, the alternating voltage supply of the two pairs of capacitor combinations for the two directions taking place either at the same frequency but with 90 ° mutual phase shift or with two frequencies, where one is n times the other, where n is an integer, and that the output signal is fed to two demodulators for phase-pure demodulation, each with its own supply voltage. Sensor according to Claim 8, characterized in that a further pair of capacitor combinations are provided, which are supplied with alternating voltage at a frequency which is approximately one times greater than the highest supply frequency. for the other pairs of capacitor combinations or the smallest divided by m, where m is an integer, and that the output signal from the sensing electrode unit is fed to at least one demodulation unit with pure demodulation for each direction sensing. A sensor according to any one of claims 5-9, characterized by a second common electrode unit (38,39,41,42,44), which is Bootstrap-coupled to the output of an operational amplifier (OP3), one input of which is connected to the common sense electrode unit (37,40). A sensor according to any one of claims 5-9, characterized by a third common electrode unit (r, 44) located close to but isolated from the sensing electrode unit, which third electrode unit is connected to ground. Sensor according to any one of the preceding claims, characterized by a force sensor with a moving part, which is connected to the moving part of the sensor, which force sensor is arranged to provide extra force in the direction or directions which the moving part tends to to move in (Figs. 5A, 5B, 6, 7A-7C, 8A-8C, 9A, 9B, 10A-10D). Sensor according to claim 12, characterized in that either of the power part mechanically coupled to the movable sensing part of the sensor or the stationary part near the coupled part is provided with a winding arrangement (L; lq; 61,62,66; 72-75) for each direction of movement, and that the second part of said parts is provided with an arrangement of magnets constantly magnetized at the time of measurement (52,53,54,55; 76,77), preferably permanent magnets, placed stationary for co-operation with the winding arrangement, and that the arrangement of winding arrangements and constantly magnetized magnets is such that for each activation of the winding arrangement for this direction the winding arrangement together with constant magnetic fields from the magnets gives a force to the moving part in the intended direction . Sensor according to Claim 12 or 13, characterized in that the holder arrangement consists of the force sensor, so that it is free-floating, ie without mechanical anchoring in the stationary arrangement (Fig. 9A). Sensor according to claim 13 or 14, characterized in that each winding is positioned so that its magnetic field, when activated, runs in substantially the same direction as a magnetic field given between a pair of magnets in the magnet arrangement, which magnets are so designed and positioned that they provide a laterally defined magnetic field which extends only partially through the winding at one side thereof, wherein when current is fed through the winding in a direction which gives a magnetic field opposite to the magnetic field through the winding, the winding tends to be pulled towards the magnetic field, so that it comes more centrally in the winding, and when current is supplied in the opposite direction, repels from the magnetic field. A sensor according to any one of claims 12-15, characterized in that a signal processing unit (180) is connected to the power sensor and the sensor, which signal processing unit is arranged to control the power sensor for movements according to predetermined conditions. Sensor according to claim 16, characterized in that the signal processing unit (180) is also connected to a measuring beam (185, 186), to which the probe is attached, and receives signals regarding the movements of the measuring beam from the measuring beam, and that the signal processing unit is arranged to supply that force. - providing the arrangement with signals, which exhibits the moving part of the probe in the direction of movement of the measuring beam and which when the probe indicates a change in the position of the moving part of the sensor 465 981 10 15 20 25 30 35 32 the measuring beam to a standstill and the energizing arrangements for reduced power in the direction of movement. Sensor according to claim 16 or 17, characterized in that the signal processing unit is a processor (180) fed with a program, which provides control of the energizing arrangements and any peripherals for the probe in accordance with preselected conditions. Sensor according to claims 17 and 18, characterized in that the processor is fed with a control program for measuring an object whose position data are known in principle and for each measuring point controls the measuring beam at maximum speed up to a position shortly before the measuring point in principle should be at, then the speed decreases to a speed which, after the probe's indication of change, gives a braking distance down to a standstill, which coincides with the change of the force-arranging arrangements from exhibited probe to a probe in a neutral position without extra power and with abutment of the probe towards the object. Sensor according to one of Claims 12 to 19, characterized in that the energizing arrangements are arranged to be supplied with signals which give mutually different energizing in different directions. A sensor according to any one of the preceding claims, included in a measuring arrangement for optical and mechanical measurement of a measuring object comprising an optical distance sensing unit with a lens unit (192) and an arrangement for giving focus to the measuring object (190), tip (196 ) in mechanical measurement against the measuring object, the displacement is characterized in that the probe can be measured against the measuring object along the optical axis of the lens unit and in between is placed on the optical axis retarded from the measuring object. 10 465 981 33 recognizes that the entire probe is placed on the optical axis (Figs. 12-15). A sensor according to claim 21, Sensor according to claim 22, characterized in that the measuring tip (196) is placed on a rod (195), which runs through a central through hole (193) in the lens unit, and that the head of the probe (194) is placed on the opposite end. about the rod against the measuring tip and placed near the lens unit. Sensor according to claim 21, characterized in that the probe itself (197, 199) is located next to the optical arrangement and is connected to its measuring tip (196 '; 196 ") by an arm which is either straight or angled on some places.