Scanning probe and method

Abstract

To provide a scanning probe for a coordinate measuring machine with inductive position sensor signal gain control.SOLUTION: A scanning probe 300 includes a stylus position detection portion 311 with field generating and sensing coils RSC, ASCC, and for which corresponding output signals are indicative of a position of a probe tip of a stylus 306. A signal processing and control circuitry 380 is configured to implement different operating regions, such as a central high gain operating region which corresponds to a central probe tip position range, as well as other lower gain operating regions, and for which transition operations may be performed for adjusting a gain. In various implementations, transition operations for adjusting a gain may include operations such as: adjusting power to a field generating coil configuration 360; adjusting a gain of a front end amplifier; altering characteristics of the sensing coils; adjusting an input range of an analog to digital converter, etc.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to precision measurement, and more particularly to coordinate measuring machine probes that utilize inductive sensing arrangements. [Background technology]

[0002] 2. Description of Related Art A coordinate measuring machine (CMM) can obtain measurements of the workpiece being inspected. One exemplary prior art CMM, described in U.S. Pat. No. 8,438,746, which is incorporated herein by reference in its entirety, includes a probe for measuring the workpiece, a movement mechanism for moving the probe, and a controller for controlling the movement. A CMM including a surface scanning probe is described in U.S. Pat. No. 7,652,275, which is incorporated herein by reference in its entirety. As disclosed therein, a mechanical contact probe or an optical probe can be scanned across the workpiece surface.

[0003] A CMM using a mechanical contact probe is also described in U.S. Pat. No. 6,971,183, the entirety of which is incorporated herein by reference. The probe disclosed therein includes a stylus having a probe tip (i.e., surface contact portion), an axial translation mechanism, and a rotational translation mechanism. The axial translation mechanism includes a translation member that allows the probe tip to move in a central axial direction of the measurement probe (also referred to as the Z direction or axial direction). The rotational translation mechanism includes a rotational member that allows the probe tip to move perpendicular to the Z direction. The axial translation mechanism is nested within the rotational translation mechanism. The probe tip position and / or workpiece surface coordinates are determined based on the displacement of the rotational member and the axial displacement of the axial translation member.

[0004] Inductive position detectors for stylus position measurement in CMM scanning probes are disclosed in U.S. Patent Application Publication Nos. 2020 / 0141714 and 2020 / 0141717, each of which is incorporated herein by reference in its entirety. The disclosed configurations include rotational and respective axial detection coil arrangements. A stylus-coupled conductive disruptor moves along the Z (axial) and XY (rotational) directions within a moving volume. A generating coil generates a varying magnetic flux encompassing the disruptor and coil, and the coil signal indicates the position of the disruptor and / or stylus.

[0005] In general, inductive sensing configurations for CMM probes can encounter a variety of issues, including signal / response nonlinearities inherent in the system's displacement response, position offsets and / or errors due to imperfect assembly and alignment, signal drift due to environmental influences on mechanical and electrical elements (e.g., due to temperature changes), and signal noise. Such issues can present particular challenges in such systems, where it is typically desirable to detect the smallest possible deflection of the probe tip from the smallest possible signal fluctuations. These types of issues can present various challenges for achieving the desired range, amplification, signal-to-noise ratio, etc., of the position signal from the probe. There is a need for improved circuitry and processing that can address such issues in CMM probes that utilize inductive sensing configurations. Summary of the Invention [Means for solving the problem]

[0006] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0007] A scanning probe for a coordinate measuring machine with inductive position sensor signal gain control is provided. The scanning probe includes a stylus suspension, a stylus position detection unit, and signal processing and control circuitry. The stylus suspension is coupled to a frame of the scanning probe and includes a stylus coupling and a stylus movement mechanism. The stylus coupling is configured to be rigidly coupled to a stylus having a probe tip. The stylus movement mechanism is configured to enable axial movement of the stylus coupling along an axial direction and rotational movement of the stylus coupling about a center of rotation.

[0008] The stylus position detection section is disposed along a central axis parallel to the axial direction and nominally aligned with the center of rotation, and includes a field-generating coil arrangement including at least one field-generating coil, an upper axial detection coil arrangement including at least one upper axial detection coil, a lower axial detection coil arrangement including at least one lower axial detection coil, N upper rotation detection coils and N lower rotation detection coils (N is an integer greater than 3), and a disruptor arrangement. The disruptor arrangement includes a conductive disruptor element that provides a disruptor region. The disruptor element is located within a disruptor movement volume along the central axis, and the disruptor element is coupled to the stylus suspension by a coupling arrangement. The disruptor element moves within the disruptor movement volume to an undeflected position in response to deflection of the stylus suspension. The disruptor element moves along the axial direction through an operational range of motion + / -Rz- in response to axial motion, and moves along orthogonal X and Y directions perpendicular to the axial direction through respective operational ranges of motion + / -Rx and + / -Ry in response to rotational motion. The field-generating coil arrangement generates a varying magnetic flux generally along the axial direction within the disruptor motion volume in response to coil drive signals.

[0009] The signal processing and control circuit is operably connected to the coils of the stylus position detector to provide the coil drive signals, and is configured to input signals including respective signal components provided by the respective rotational and axial detection coils (i.e., the upper and lower rotational detection coils and the upper and lower axial detection coils), and output signals indicative of the axial and rotational positions of the probe tip, where a change in the output signal correspondingly indicates a change in at least one of the axial or rotational positions of the probe tip. The signal processing and control circuit is configured to operate over a plurality of operating regions, including a central high-gain operating region corresponding to a central high-gain probe tip position range, and a first pair of lower-gain operating regions corresponding to respective lower-gain probe tip position ranges, where the central high-gain operating region is between the operating regions of the first pair of lower-gain operating regions. In various embodiments, the gain of each operating region corresponds to the ratio of the magnitude of the change in the output signal to the change in probe tip position of the respective operating region (e.g., the first pair of lower-gain operating regions have respective gains lower than the gain of the central high-gain operating region).

[0010] In various embodiments, the signal processing and control circuitry is configured to perform a transition operation in response to determining that the probe tip has moved from a position within the central-high-gain probe tip position range of the central-high-gain operating region to a position within the lower-gain probe tip position range of a respective operating region of the first pair of lower-gain operating regions, the transition operation causing the signal processing and control circuitry to transition from operation in the central-high-gain operating region having a high gain to operation in the respective operating region having a lower gain.

[0011] In various embodiments, the plurality of operating regions further includes a second pair of lower gain operating regions corresponding to respective lower gain probe tip position ranges, wherein the operating region of the first pair of lower gain operating regions may be between the second pair of lower gain operating regions, the second pair of lower gain operating regions having lower respective gains than the first pair of lower gain operating regions. The signal processing and control circuitry may be further configured to correspondingly perform a transition operation in response to determining that the probe tip has moved to a position within the lower gain probe tip position range of the respective operating region of the second pair of lower gain operating regions, the transition operation causing the signal processing and control circuitry to transition to operation in the respective operating region of the second pair of lower gain operating regions having a lower gain.

[0012] In various embodiments, the plurality of operating regions may further include a pair of saturated operating regions corresponding to respective saturated probe tip position ranges, a second pair of lower gain operating regions between the pair of saturated operating regions, the pair of saturated operating regions corresponding to saturated conditions where there is no nominal change in the output signal due to changes in probe tip position and nominal no corresponding gain. In various embodiments, the signal processing and control circuitry may include one or more amplifiers configured to amplify the signal from the coil of the stylus position detector, the saturated condition corresponding to saturation of at least one of the one or more amplifiers.

[0013] In various embodiments, the central high-gain operating region corresponding to the central high-gain probe tip position range also corresponds to the angular position range of the disruptor element and corresponds to the central high-gain element position range configured to be utilized in combination with a stylus of a first stylus length. In such configurations, for a stylus of a second stylus length, the central high-gain element position range may be configured to be modified to be at least one of shorter so as to be configured to be utilized with a second stylus length that is longer than the first stylus length, or longer so as to be configured to be utilized with a second stylus length that is shorter than the first stylus length.

[0014] In various embodiments, the signal processing and control circuitry is further configured to perform a zeroing operation to adjust a zero position of the central high-gain operating region. In various embodiments, the signal processing and control circuitry is further configured to have at least a position range of the central high-gain operating region expanded to at least one of encompass manufacturing tolerances during factory calibration or encompass variations that may occur due to orientation of the scanning probe during measurement operations.

[0015] In various embodiments, the transition operation includes reducing the power of the field-generating coil arrangement to reduce the ratio of the magnitude of the change in output signal to the change in probe tip position, corresponding to a lower gain. In various embodiments, reducing the power of the field-generating coil includes reducing the coil drive signal.

[0016] In various embodiments, the signal processing and control circuitry includes one or more variable gain amplifiers configured to amplify signals from the coils of the stylus position detection unit, and includes reducing the gain of the one or more variable gain amplifiers to reduce the ratio of the magnitude of change in output signal to change in probe tip position, corresponding to a lower gain.

[0017] In various embodiments, the method includes modifying a characteristic of one or more of the rotational detection coils to reduce the ratio of the magnitude of the change in output signal to the change in probe tip position, corresponding to a lower gain. In various embodiments, modifying the characteristic of the one or more rotational detection coils includes utilizing at least one of a relay or a switch to effectively reduce the operating size of the one or more rotational detection coils.

[0018] In various embodiments, the signal processing and control circuitry includes one or more analog-to-digital converters configured to convert analog signals from the coils of the stylus position detection unit to digital signals, and the transition operation includes changing the input range of the one or more analog-to-digital converters to reduce the ratio of the magnitude of change in the output signal to the change in probe tip position, corresponding to a lower gain.

[0019] In various embodiments, a determination that the probe tip has moved from a position within the central high-gain probe tip position range to a position within the respective lower-gain probe tip position range is made according to an analysis of position samples including signals from the coils of the stylus position detector. In various embodiments, after a determination that the probe tip has moved into the respective lower-gain probe tip position range is made based on an analysis of the corresponding position samples, and after a transition operation has been performed to correspondingly lower the gain, a new position sample is obtained and utilized to indicate the probe tip position in place of the position sample obtained before the transition operation was performed to lower the gain.

[0020] In various embodiments, a method is provided that includes determining three-dimensional position information based on inductive detection signals generated by a scanning probe as the scanning probe moves along a surface of a workpiece. In various embodiments, determining the three-dimensional position information based on the inductive detection signals generated by the scanning probe includes providing coil drive signals, inputting signals including respective signal components provided by the respective rotational and axial detection coils, and outputting signals indicative of axial and rotational positions of a probe tip, wherein a change in the output signal correspondingly indicates a change in at least one of the axial or rotational positions of the probe tip, the three-dimensional position information being determined based on the output signal, determining whether to transition from a central high-gain region of operation to a lower-gain region of operation based on the indicated position of the probe tip, and performing a transition operation in response to determining that a transition from the central high-gain region of operation to a lower-gain region of operation should be made, wherein the transition operation results in a transition from operation in the central high-gain region of operation having a high gain to operation in the respective lower-gain region of operation having a lower gain.

[0021] In various embodiments, the central high-gain operating region corresponding to the central high-gain probe tip position range also corresponds to a central high-gain element position range that corresponds to an angular position range of the disruptor element and that is configured to be utilized in combination with a stylus of a first stylus length, and the method includes modifying the central high-gain element position range based on a determination that a stylus of a second length different from the first length is coupled to the stylus coupling portion.

[0022] In various embodiments, the scanning probe is included in a system having a drive mechanism and a mount that attaches the scanning probe to the drive mechanism. [Brief explanation of the drawings]

[0023] [Figure 1]1 illustrates various exemplary components of a measurement system including a CMM that utilizes a scanning probe as disclosed herein; [Figure 2] FIG. 1 is a block diagram illustrating various elements of a scanning probe coupled to a CMM to provide rotational and axial position signals. [Figure 3] 1 shows a portion of a first exemplary embodiment of a stylus suspension coupled to a stylus and a first exemplary embodiment of a stylus position detector for detecting the position of the stylus suspension. [Figure 4] 4 shows a cross section of one embodiment of the stylus suspension of FIG. 3 contained within the body frame of a scanning probe; [Figure 5] FIG. 5 is a partial schematic isometric view of an alternative embodiment of the stylus position detector shown in FIGS. 3 and 4. [Figure 6] FIG. 6 is a partial schematic isometric view of certain elements of the stylus position detector shown in FIG. 5. [Figure 7] FIG. 10 is a graph showing an example of an operating region with different gain adjustments. [Figure 8] FIG. 10 is a graph showing an example of an operating region with different gain adjustments. [Figure 9] FIG. 10 is a graph showing an example of an operating region with different gain adjustments. [Figure 10] FIG. 10 is a graph showing an example of an operating region with different gain adjustments. [Figure 11] FIG. 1 illustrates a process for performing a zeroing operation. [Figure 12] FIG. 10 illustrates a process for increasing the range of the central high-gain operating region. [Figure 13] 4 is a flow diagram illustrating an exemplary embodiment of a routine for determining and transmitting position samples. [Figure 14] 4 is a flow chart illustrating an exemplary embodiment of a routine for operating a scanning probe. DETAILED DESCRIPTION OF THE INVENTION

[0024] 1 is a diagram illustrating various exemplary components of a measurement system 100 including a CMM 200 utilizing a scanning probe 300 as disclosed herein. The measurement system 100 includes an operation unit 110, a motion controller 115 for controlling movement of the CMM 200, a host computer 120, and the CMM 200. The operation unit 110 is coupled to the motion controller 115 and may include a joystick 111 for manually operating the CMM 200. The host computer 120 is coupled to the motion controller 115 and operates the CMM 200 and processes measurement data of the workpiece W. The host computer 120 includes an input means 125 (e.g., a keyboard, etc.) for inputting measurement conditions, for example, and an output means 130 (e.g., a display, printer, etc.) for outputting measurement results, for example.

[0025] The CMM 200 includes a drive mechanism 220 located on a surface plate 210 and a mount 224 for mounting the scanning probe 300 to the drive mechanism 220. The drive mechanism 220 includes X-axis, Y-axis, and Z-axis slide mechanisms 222, 221, and 223, respectively, for moving the scanning probe 300 in three dimensions. A stylus 306 attached to the end of the scanning probe 300 includes a probe tip 348 (e.g., which may additionally or alternatively be referred to as a contact portion 348). As described in more detail below, the stylus 306 is attached to a stylus suspension of the scanning probe 300, which allows the probe tip 348 to freely change its position in three directions as the probe tip 348 moves along a measurement path on the surface of the workpiece W.

[0026] Figure 2 is a block diagram illustrating various elements of a scanning probe 300 that is coupled to a CMM 200 and provides rotational (e.g., X, Y) and axial (e.g., Z) position signals. The scanning probe 300 includes a probe body 302 (e.g., including a frame) that incorporates a stylus suspension 307 and a stylus position detection portion 311. The stylus suspension 307 includes a stylus coupling portion 342 and a stylus movement mechanism 309. The stylus coupling portion 342 is rigidly coupled to a stylus 306. The stylus movement mechanism 309 is configured to allow axial movement of the stylus coupling portion 342 and attached stylus 306 along an axial direction and rotational movement of the stylus coupling portion 342 and attached stylus 306 about a center of rotation, which are described in more detail below with respect to Figures 3 and 4. The scanning probe 300 includes signal processing and control circuitry 380 which is connected to the stylus position detector 311 and may regulate its operation and perform related signal processing, all of which are described in more detail below.

[0027] As shown in FIG. 2 , the stylus position detection section 311 uses inductive detection principles and includes a receive coil section 370, a field-generating coil arrangement 360, and a disruptor element 351 (which may be part of a disruptor arrangement 350, which may have multiple components in some embodiments). The receive coil section 370 may include a rotational detection coil section (also called a rotational detection coil) RSC and an axial detection coil arrangement ASCC. Simply put, the moving disruptor element 351 (or more generally, the disruptor arrangement 350) causes position-dependent variations in the changing magnetic field generated by the field-generating coil arrangement 360. The receive coil section 370 responds to the changing magnetic field and its variations caused by the disruptor element 351. In particular, the rotational detection coil section RSC outputs at least first and second rotational signal components RSig (e.g., X and Y position signals) indicative of the rotational position of the stylus coupling section 342 on corresponding signal lines, and the axial detection coil arrangement ASCC outputs one or more axial signal components Asig (e.g., Z position signals) indicative of the axial position of the stylus coupling section 342 on corresponding signal lines, as will be described in more detail below, e.g., with reference to FIGS. 3, 5, and 6. In various embodiments, the signal processing and control circuitry 380 receives the rotational signal components RSig and the axial signal components ASig and may perform various levels of related signal processing in various embodiments. For example, in one embodiment, the signal processing and control circuitry 380 may combine and / or process the signal components from the various receiving coils in various relationships and provide the results in a desired output format as rotational and axial position signal outputs RPSOut and APSOut via the mounting section 224. One or more receivers (e.g., within the CMM 200, the motion controller 115, the host computer 120, etc.) may receive the rotational and axial position signal outputs RPSOt and APSOut and may use one or more associated processing and control units to determine the three-dimensional position of the probe tip of the stylus coupling 342 and / or attached stylus 306 as its probe tip 348 moves along the surface of the workpiece W being measured.

[0028] FIG. 3 is a partial schematic diagram illustrating a portion of a first exemplary embodiment of a stylus suspension 407, shown schematically coupled to a stylus 406, and a partial schematic cross-section of a first exemplary embodiment of a stylus position detection portion 411 for detecting the position of the stylus suspension 407 and / or the stylus 406. Certain numbered components 4XX in FIG. 3 may correspond to and / or have similar operation as similarly numbered corresponding components 3XX in FIG. 2 and will be understood by analogy thereto and otherwise described below. This numbering scheme, illustrating elements of analogous design and / or function, also applies to FIGS. 4-12 below. As shown in FIG. 3, the stylus suspension 407 includes a stylus-moving mechanism 409 and a stylus coupling portion 442. The stylus coupling portion 442 is configured to be securely coupled to a stylus 406 having a probe tip 448 for contacting a surface S of a workpiece W (not shown).

[0029] As will be explained in more detail below with respect to Figure 4, a stylus movement mechanism 409 is attached to the frame of the scanning probe and is configured to allow axial and rotational movement of the stylus coupling 442 and attached stylus 406 so that the probe tip 448 can vary its position in three directions to follow the shape of the surface S. For purposes of explanation, the vertical and horizontal directions in the plane of Figure 3 are defined as the Z and Y directions, respectively, and the direction perpendicular to the plane of the page is defined as the X direction. The direction of the central axis CA, also referred to as the axial direction, of the scanning probe 300 coincides with the Z direction in this figure.

[0030] 3 depicts a rotational movement portion of stylus movement mechanism 409, including a rotating member 436, a flexure element 440, and a moving member 412 disposed within rotating member 436. As described in more detail below with respect to FIG. 4, flexure element 440 enables rotational movement of rotating member 436 about a center of rotation RC. As described in more detail below, in various embodiments, rotational detection coils TRSCi and BRSCi (where i is an index integer that identifies a particular coil) and stylus position detection portion 411 can detect the rotational position of disruptor element 451 and thereby the rotational position of moving member 412 (e.g., in the X and Y directions), and axial detection coil arrangements (also referred to as axial detection coils) TASCC and BASCC can detect the axial position of disruptor element 451 and thereby the axial position of moving member 412 (e.g., in the Z direction).

[0031] As shown in Figure 3, a first exemplary embodiment of the stylus position detection portion 411 includes a disruptor element 451 (or more generally, a disruptor arrangement 450) coupled to a moving member 412, which moves relative to the frame of the scanning probe (e.g., the frame is included as part of the scanning probe body) within a disruptor movement volume MV located between upper and lower coil substrates 471T and 471B, respectively. As shown in Figure 3, the moving member 412 extends through and moves within a hole 472 located along a central axis CA of the lower coil substrate 471B. The attached disruptor element 451 moves within the disruptor movement volume MV relative to an undeflected position UNDF (which may correspond, for example, to a zero or reference position) in response to deflections of the stylus suspension 407 and moving member 412.

[0032] Various other components of the stylus position detection section 411 (e.g., the receive coil section 470 and the field-generating coil arrangement 460) may be fixed relative to the frame unless otherwise noted. In the embodiment shown in FIG. 3, the field-generating coil arrangement 460 includes a single, planar field-generating coil 461 located approximately in the midplane of the disruptor movement volume MV, nominally planar, and orthogonal to the central axis CA. As outlined above with reference to FIG. 2, the receive coil section 470 may generally include a rotational detection coil section (also referred to as a rotational detection coil) RSC and an axial detection coil arrangement ASCC. The rotational position detection arrangement RSC generally includes upper rotational detection coils TRSCi and lower rotational detection coils BRSCi. In the cross-section shown in FIG. 3, only two upper rotational detection coils TRSC1 and TRSC2 and two lower rotational detection coils BRSC1 and BRSC2 are shown. These rotational detection coils may provide signal components indicative of the position of the disruptor element 451 along the Y direction. In particular, those signal components vary according to the amount of displacement ΔY of the disruptor element 451 along the Y direction, and are therefore indicative of the amount of displacement ΔY. The displacement ΔY determines the amount of relative "overlap" between the disruptor element 451 and the various rotational detection coils TRSCi and BRSCi, and thereby their amount of coupling to the changing magnetic fields generated by the field-generating coils 461 (which determine the resulting signal components). Other rotational detection coils (not shown) may provide signal components indicative of the position of the disruptor element 451 along the X-axis direction.

[0033] The axial detector coil arrangement ASCC generally includes an upper axial detector coil arrangement TASCC and a lower axial detector coil arrangement BASCC. In the embodiment shown in FIG. 3, the upper axial detector coil arrangement TASCC includes a single upper axial detector coil at least partially surrounding the central axis CA, and the at least one lower axial detector coil includes a single lower axial detector coil at least partially surrounding the central axis CA, as shown. These axial detector coils are always fully "overlapped" by the disruptor elements 451 in this particular exemplary embodiment. Thus, their signal components are nominally responsive only to the position of the disruptor elements 451 along the axial or Z direction and are indicative of the position of the disruptor elements 451 along the Z direction. The generation of the various signal components is described in more detail below with reference to FIGS. 5 and 6.

[0034] Similar to the operation outlined above with reference to FIG. 2 , during operation, the moving disruptor element 451 induces position-dependent local variations in the changing magnetic field along the axial direction generated by the field-generating coil 461. The receive coil section 470 responds to the changing magnetic field caused by the disruptor element 451 and variations therein and outputs rotational and axial signal components RSig and ASig that can be processed to determine the rotational position (e.g., Y and X positions, and corresponding signals) and axial position (e.g., Z position) of the disruptor element 451, as outlined above with reference to FIG. 2 and described in further detail below. It will be appreciated that the position of the disruptor element 451 is related, by known geometry, to the position of the stylus coupling section 442 and / or its probe tip 448, such that a signal / position indicative of one of the positions will also be indicative of the other position. For example, for small rotation angles, for an illustrated movement or displacement ΔY of the disruptor element 451 along the Y direction away from null (e.g., from the undeflected position UNDF), ΔY=Hθ Y (Formula 1) where H is the distance from the center of rotation RC to the nominal face of the disruptor element 451, and θ Yis the slope of the rotational movement of the rotating member 436 (and moving member 412) in a plane parallel to the Y direction (i.e., rotation about an axis parallel to the X axis at the center of rotation RC). When larger rotation angles are used in various embodiments, similar expressions that are accurate for larger rotation angles may be used, as known in the art. The slope component θ of the rotational movement Y Y-direction movement or displacement Y of the probe tip 448 of the stylus 406 away from the null (e.g., corresponding to the undeflected position UNDF) relative to STYLUS is approximated as follows: ΔY STYLUS =θ Y *(h S +l S )(Formula 2) In the formula, h S is the distance from the end of the stylus coupling portion 442 to the center of rotation RC, and l S is the length of the stylus 406. Combining equations 1 and 2, the ratio of the displacement ΔY of the disruptor element 451 relative to the Y-direction displacement at the probe tip 448 is approximated as: ΔY / ΔY STYLUS =H / (h S +l S )(Formula 3)

[0035] It will be understood that the translation component of the X coordinate is similar to the formula above and will not be described in further detail herein. S may be used in a formula (e.g., for system trigonometry) to determine the XY position of the probe tip 448 based on the signal from the rotational detection coil RSC (e.g., indicating the XY position of the disruptor element 451). In terms of the Z coordinate displacement or position component, the Z-direction displacement ΔZ at the contact point of the stylus (e.g., the probe tip 448) STYLUS , the displacement ΔZ (not shown) of the disruptor element 451 along the axial or Z direction away from the null (e.g., corresponding to the undeflected position UNDF) may be approximated as: TIFF0007760363000001.tif8154

[0036] FIG. 4 is a cross-sectional view of one embodiment of a stylus suspension 407′ usable as the stylus suspension 407 depicted in FIG. 3, and a partial schematic diagram illustrating one embodiment of a stylus position detection portion 511 similar to the stylus position detection portion 411 shown in FIG. 3, and a signal processing and control circuit 480. The aforementioned elements are shown contained within the frame 408 of the probe body 402 of the scanning probe 400. The substrates 571T, 571B of the stylus position detection portion 511 and the field generating coil 561 or their substrates (e.g., printed circuit-type substrates) may be positioned for proper operation within the scanning probe 400 using adjustment and mounting portions 417 or other known techniques. Various signal connections associated with the stylus position detection portion 511 may be provided by connectors (e.g., flex print and / or wire connections) 419, etc., in accordance with known techniques. In some embodiments, some or all of the signal processing and control circuitry 480 may be provided as a separate circuit assembly, as depicted in FIG. 4. In other embodiments, some or all of the signal processing and control circuitry 480 may be combined on board the stylus position detection portion 511, if desired.

[0037] 4, the stylus suspension 407' includes a stylus movement mechanism 409 and a stylus coupling 442 coupled to the stylus 406. The stylus movement mechanism 409 may include a movement member 412, a rotation member 436, a flexure element 440 coupled to the body frame 408 to support and allow rotational movement of the rotation member 436, and flexure elements 414 and 415 (i.e., referred to as first flexure elements) that support the movement member 412 and couple it to the rotation member 436 to allow axial movement of the movement member 412. The scanning probe 400 includes a stylus position detection portion 511, the components and operation of which are described in more detail below with reference to FIG. 5, for determining the position and / or movement of the stylus movement mechanism 409 and / or a probe tip 448 of the stylus 406.

[0038] The bending element 440 (i.e., referred to as the second bending element) may be disposed between the respective planes of the pair of bending elements 414 and 415 (i.e., referred to as the first bending elements) in the axial direction O. A suitable bending design for the bending elements 414, 415, and 440 may be determined according to principles known in the art. For example, one possible embodiment is shown in U.S. Pat. No. 9,791,262, which is incorporated herein by reference in its entirety. The rotating member 436 may have a symmetrical shape with respect to the second bending element 440 and may integrally include two ring portions 436A, two connecting portions 436B, and a cylindrical portion 436C. The peripheries of the first bending elements 414 and 415 are fixed to the ring portion 436A. The connecting portion 436B extends inward of the ring portion 436A to connect to the cylindrical portion 436C having a hollow center. First bending elements 414 and 415 may be disposed at symmetrical distances relative to second bending element 440, although such an embodiment is exemplary only and not limiting.

[0039] An axial movement mechanism 410 including a movement member 412 is supported inside the rotating member 436, and the rotating member 436 and the axial movement mechanism 410 together form a movement module that is part of the stylus movement mechanism 409. The axial movement mechanism 410 allows the probe tip 448 to move in the axial direction O. A rotational movement mechanism 434 including the rotating member 436 allows the probe tip 448 of the stylus 406 to move transversely (e.g., approximately perpendicularly) to the axial direction O using rotational movement about a center of rotation RC.

[0040] The moving member 412 integrally includes a lower portion 412A, a rod portion 412B, and an upper portion 412C. As generally described above with reference to FIG. 3 and described in more detail below with respect to the stylus position detection portion 511 shown in FIG. 5, a disruptor element 551 attached to the upper portion 412C of the moving member 412 functions as both a rotational and axial position indicating element. The rod portion 412B is disposed between a pair of first bending elements 414 and 415. The rod portion 412B is housed within the rotating member 436. The lower portion 412A is formed below the rod portion 412B, and a stylus coupling portion 442 (e.g., a flange member) is attached to the lower portion 412A. A flange portion 444 is provided for mounting the stylus 406. The flange portion 444 and the stylus coupling portion 442 may together form a detachable coupling mechanism (e.g., a kinematic linkage or coupling of a known type) that allows for repeatable positioning between various styli 406 and the stylus coupling portion 442 (e.g., in the event that a collision causes the stylus to fall off or when the stylus is intentionally changed).

[0041] Figure 5 is a partial schematic isometric view of one embodiment of a stylus position detector 511' similar to the stylus position detector 511 shown in Figure 4, highlighting certain aspects. Stylus position detectors 511' and 511 are similar except for differences in field-generating coil arrangement 560, which are described further below. In general, stylus position detector 511' will be understood to include certain components similar to those of stylus position detectors 311, 411 and 511 of Figures 2, 3 and 4 and operate similarly unless otherwise described below.

[0042] 5, the stylus position detection section 511′ includes a receive coil section 570, a disruptor arrangement 550 including a disruptor element 551, and a field-generating coil arrangement 560. In various embodiments, the disruptor element 551 (or more generally the disruptor arrangement 550) may include a conductive plate or loop, or parallel conductive plates or loops (e.g., fabricated on opposite sides of a printed circuit board and patterned by printed circuit fabrication techniques), or any other desired operating arrangement that provides a disruptor region (e.g., an interior region thereof). The disruptor element 551 is located along a central axis CA of the disruptor movement volume MV between the upper coil substrate 571T and the lower coil substrate 571B and is coupled to the stylus suspension section 507 by a coupling arrangement (e.g., including a moving member 512). For purposes of explanation, the disruptor element 551 may be described as moving relative to an undeflected position shown in Figure 5 (see undeflected position UNDF in Figure 3) in response to deflection of the stylus suspension 507 and / or stylus 506 and / or moving member 512. The disruptor element may be described as moving along the axial direction in displacement increments ΔZ over an operational range of travel + / -Rz in response to axial movement, and moving along orthogonal X and Y directions orthogonal to the axial direction (Z direction) in displacement increments ΔX and ΔY over respective operational ranges of travel + / -Rx and + / -Ry in response to rotational movement. Specified or expected operational ranges of travel are described in more detail below.

[0043] The receive coil section 570 may include a planar upper coil substrate 571T including N upper rotating detector coils TRSC (e.g., TRSC1-TRSC4, where N=4) and an upper axial detector coil arrangement TASCC (e.g., including a single individual coil as shown in this embodiment), and a planar lower coil substrate 571B including N lower rotating detector coils BRSC (e.g., BRSC1-BRSC4, where N=4) and a lower axial detector coil arrangement BASCC (e.g., including a single individual coil as shown in this embodiment). The upper and lower coil substrates 571T and 571B are mounted in a fixed relationship to the frame of the scanning probe, with the lower coil substrate 571T being closer to the stylus 506 and / or stylus suspension 507. The upper and lower coil substrates 571T and 571B are nominally parallel to each other and may be nominally perpendicular to the central axis CA, and are spaced apart along the central axis CA, with the disruptor movement volume MV located between them. The various detection coils shown in FIG. 5 are represented by "closed loops" for ease of illustration, but it should be understood that all coils include a winding or conductor having first and second connected ends configured to operate as one or more inductively coupled "turns" (e.g., as represented in FIG. 6).

[0044] The field-generating coil arrangement (e.g., field-generating coil arrangement 560) generally includes at least a first field-generating coil located proximate to the disruptor movement volume MV, nominally planar, and orthogonal to the central axis CA. In contrast to the single planar field-generating coil 461 in the embodiment shown in FIG. 3 (which is located approximately in the mid-plane of the disruptor movement volume MV), in the embodiment shown in FIG. 5, field-generating coil arrangement 560 includes a pair of planar field-generating coils 561T and 561B (located on upper and lower substrates 571T and 571B, respectively) that are approximately equidistant from the mid-plane of the disruptor movement volume MV along the central axis CA, and are nominally planar and orthogonal to the central axis CA. Generally speaking, either field-generating coil arrangement 460 or 560 may be used with the receive coil section 570. In certain embodiments, the field-generating coil arrangement includes at least a first field-generating coil configured such that the projection of its coil area along the axial direction (Z direction) encompasses the disruptor area of ​​the disruptor arrangement 550 (e.g., of the disruptor element 551) and the conductive plane or loop that provides the coil area of ​​all rotational detection coils RSCi and axial detection coils ASCC located on the upper and lower coil substrates 571T and 571B. Generally, the field-generating coil arrangement is configured to generate a varying magnetic flux generally along the axial direction within the disruptor movement volume MV in response to coil drive signals, as desired for operation of the stylus position detector 511′. While the various field-generating coils shown in FIG. 5 are represented for ease of explanation by a single “closed loop” including a wide, flat conductive trace (its ends shown), in an actual device, all coils will have first and second connected ends (e.g., as represented in FIG. 6 ) and will include a winding or conductor configured to operate as one or more field-generating “turns.”

[0045] As shown in FIG. 5, the projection of the disruptor element 551 along the axial direction through the internal coil region of the upper axial detector coil arrangement TASCC (e.g., as shown by the thin dashed line PRJ in FIG. 5) defines an upper axial detector overlap area TASOA (indicated by the dot pattern filling that internal coil area), and the projection of the disruptor element 551 along the axial direction through the internal coil region of the lower axial detector coil arrangement BASCC defines a lower axial detector overlap area BASOA (indicated by the dot pattern filling that internal coil area). Similarly, the projection of the disruptor element 551 along the axial direction through the internal coil region of any upper rotating detector coil TRSCi (e.g., TRSC1-TRSC4) defines a respective upper rotating coil detector overlap area TRSCOAi (e.g., TRSCOA1-TRSCOA4), as indicated by the dot patterns filling the various respective overlap areas shown in FIG. 5, where i is an individual coil identification index ranging from 1 to N. The projection of the disruptor element 551 along the axial direction through the internal coil region of each lower rotating detection coil BRSCi (e.g., BRSC1-BRSC4) defines a respective lower rotating coil detection overlap region BRSCOAi (e.g., TRSCOA1-TRSCOA4), as shown by the dot patterns filling the various respective overlap regions shown in FIG. 5.

[0046] With respect to axial position detection in the stylus position detection section (e.g., 511′), the receive coil section (e.g., 570) and disruptor element (e.g., 551) are generally configured to provide upper and lower axial detection overlap areas TASOA and BASOA, respectively, where the amounts of overlap areas TASOA and BASOA are either fixed or independent of the position of the disruptor element 551 within the operational travel ranges + / -Rz, + / -Rx, and + / -Ry. It will be appreciated that for a particular scanning probe, the operational travel ranges can be defined or specified, as needed, in combination with the particular stylus position detection section configuration of the probe, to meet this requirement. Thus, the signal components generated at the upper axial detector coil arrangement TASCC and the lower axial detector coil arrangement BASCC are nominally independent of rotational movement (i.e., the position of the disruptor element 551 along the X and Y directions) and are nominally sensitive only to variations in "proximity" or gap to the disruptor element 551, which varies with the axial (Z) position or displacement ΔZ of the disruptor element 551. In operation, currents induced in the disruptor element 551 by the changing magnetic field of the field generating coil arrangement 560 cause opposing magnetic fields. Generally speaking, as the disruptor element 551 moves upward along the axial (Z) direction in FIG. 5, the opposing magnetic field couples more strongly to the upper axial detector coil arrangement TASCC, reducing its signal components resulting from the changing magnetic field. Conversely, the opposing magnetic field couples more weakly to the lower axial detector coil arrangement BASCC, increasing its signal components resulting from the changing magnetic field. By transformation as used in this disclosure, the signal component SIGTASCC can be referred to as the signal component arising from a particular upper axial detection coil arrangement (or coil), such as TASCC.

[0047] It will be appreciated that in the undeflected position UNDF, the net signal components SIGTASCC and SIGBASCC may be approximately balanced. For small displacements ΔZ, such as those expected during operation, the net signal components SIGTASCC and SIGBASCC may vary approximately linearly and inversely compared to one another. In one embodiment, the axial displacement or position ΔZ may be indicated by or correspond to the following signal relationship: ΔZ = function [(SIGBASCC-SIGTASCC) / (SIGBASCC+SIGTASCC)] (Equation 5)

[0048] This signal relationship is merely exemplary and not limiting. In various embodiments, this signal relationship may be adjusted or compensated for, as needed, by additional calibration or signal processing operations, including operations to reduce the effects of geometric and / or signal cross-coupling between various displacement directions or signal components. In various embodiments, the upper axial detection coil arrangement includes at least one upper axial detection coil that is not one of the N upper rotation detection coils and is positioned closer to the central axis than the upper rotation detection coil, and the at least one upper axial detection coil and the disruptor element are characterized in that the at least one upper axial detection coil has a smaller internal coil area than the disruptor element, and the projection of the disruptor element along the axial direction completely fills the at least one upper axial detection coil area for any position of the disruptor element within the operational range of travel + / -Rz, + / -Rx, and + / -Ry, such that the upper axial detection overlap area TASOA is not altered by the position of the disruptor element. Similarly, in various such embodiments, the lower axial detector coil arrangement includes at least one lower axial detector coil that is not one of the N lower rotation detector coils and is positioned closer to the central axis than the lower rotation detector coil, and the at least one lower axial detector coil and the disruptor element are characterized in that the at least one lower axial detector coil has a smaller internal coil area than the disruptor element, and the projection of the disruptor element along the axial direction completely fills the at least one lower axial detector coil area for any position of the disruptor element within the operational range of travel + / -Rz, + / -Rx, and + / -Ry, whereby the lower axial detector overlap area TASOA is not altered by the position of the disruptor element. It may be seen that the particular embodiment of the stylus position detector 511' shown in FIG. 5, in which the upper axial detector coil arrangement TASCC and the lower axial detector coil arrangement BASCC each include a single detector coil, conforms to this specification. It will be understood that various configurations of the upper axial detection coil arrangement TASCC and the lower axial detection coil arrangement BASCC may be used, and the particular configuration shown in FIG. 5 is illustrative only and not limiting.

[0049] With respect to rotational position detection in the stylus position detection section (e.g., 511′), the receive coil section (e.g., 570) and disruptor elements (e.g., 551) are generally configured to provide N complementary pairs of rotational detection coils CPi (e.g., CP1-CP4, where N=4), each including an upper rotational detection coil TRSCi and a lower rotational detection coil BRSCi, such that for any complementary pair CPi, for any disruptor element displacement increment within any operational range of travel + / -Rz, + / -Rx, and + / -Ry, the magnitude of change in the overlap areas TRSCOAi and BRSCOAi associated with that disruptor displacement increment is nominally the same for that complementary pair. It will be understood that for a particular scanning probe, the operational range of travel may be defined or specified in combination with the particular stylus position detection section configuration, if necessary to meet this requirement. The table CPTable in FIG. 5 lists each rotational detection coil TRSCi and BRSCi for each complementary pair CPi in the embodiment shown in FIG. 5.

[0050] By adhering to the foregoing principles, the complementary pair CPi shown in FIG. 5 may be used to compensate for or eliminate certain cross-coupling errors and / or simplify the signal processing required to provide accurate rotational position or displacement measurements (e.g., along the X and / or Y directions). In particular, pairs of signal components arising in the complementary pair CPi of rotational detection coils in the embodiment shown in FIG. 5 may be combined or processed in a relationship that provides a resultant output signal that is nominally insensitive to variations in “proximity” or gap between the individual coils of the complementary pair and the disruptor element 551. That is, the resultant output signal may be insensitive to the axial (Z) position or displacement ΔZ of the disruptor element 551 and is nominally sensitive only to rotational position or displacement (e.g., along the X and / or Y directions), as will be described in more detail below. 5, a displacement of disruptor element 551 with a displacement component ΔY along the Y-axis direction increases (or decreases) the overlap area TRSCOA2 and BRSCOA2 of complementary pair CP2 and decreases (or increases) the overlap area TRSCOA1 and BRSCOA1 of complementary pair CP1. Similarly, a displacement of disruptor element 551 with a displacement component ΔX along the X-axis direction increases (or decreases) the overlap area TRSCOA3 and BRSCOA3 of complementary pair CP3 and decreases (or increases) the overlap area TRSCOA4 and BRSCOA4 of complementary pair CP4.

[0051] As outlined above, during operation, current induced in the disruptor element 551 by the changing magnetic field of the field generating coil arrangement 560 causes an opposing magnetic field. Generally speaking, the signal component SIGTRSCi (or SIGBRSCi) generated in any rotational detection coil TRSCi (or BRSCi) will decrease as the proximal portion of the disruptor element 551 approaches that rotational detection coil along the axial direction or as its overlap TRSCOAi (or BRSCOAi) with that rotational detection coil increases.

[0052] For complementary pairs CP1-CP4 shown in FIG. 5 (the coils of complementary pair CPi may be identical and aligned axially), it will be appreciated that in the illustrated undeflected position UNDF, the signal components (e.g., SIGTRSC1 and SIGBRSC1) of each complementary pair may be approximately balanced. According to the principles outlined above, for a small displacement ΔZ, such as that expected during operation, for a portion of disruptor element 551 (e.g., CP1) proximate to a complementary pair, the net signal components (e.g., SIGTRSC1 and SIGBRSC1) may vary approximately linearly and inversely relative to one another. Thus, the sum of such signals for complementary pair CPi is nominally insensitive to ΔZ associated with the proximate portion of disruptor element 551. 5, the ends of the disruptor element 551 may be parallel to the X and Y directions, such that within the operational travel ranges + / -Rx and + / -Ry, the Y direction displacement component does not alter the rotating coil detection overlap areas TRSCOA3, BRSCOA3, and / or TRSCOA4 and BRSCOA4, and the X direction displacement component does not alter the rotating coil detection overlap areas TRSCOA2, BRSCOA2, and / or TRSCOA1 and BRSCOA1. Thus, in one embodiment, the rotational displacement or position component ΔX along the X direction, ideally regardless of ΔZ and / or ΔY, may be indicated by or correspond to the following signal relationship: ΔX = function [(SIGTRSC3 + SIGBRSC3) - (SIGTRSC4 + SIGBRSC4)] ÷ [(SIGTRSC3+SIGBRSC3)+(SIGTRSC4+SIGBRSC4)] (Formula 6)

[0053] Similarly, in one embodiment, the rotational displacement or position component ΔY along the Y direction, ideally independent of ΔZ and / or ΔX, may be indicated by or correspond to the following signal relationship: ΔY = function [(SIGTRSC2 + SIGBRSC2) - (SIGTRSC1 + SIGBRSC1)] ÷ [(SIGTRSC2+SIGBRSC2)+(SIGTRSC1+SIGBRSC1)] (Formula 7)

[0054] These signal relationships are merely exemplary and not limiting, and in various embodiments, these signal relationships may be adjusted or compensated for, as needed, by additional calibration or signal processing operations, including operations to reduce the effects of geometric and / or signal cross-coupling between various displacement directions or signal components.

[0055] In some particularly advantageous embodiments, the receive coil section (e.g., 570) and disruptor element (e.g., 551) are configured such that for any complementary pair CPi and any disruptor element displacement increment within the operational travel ranges + / -Rz, + / -Rx, and + / -Ry, the magnitude and sign of the change in overlap area TRSCOAi and BRSCOAi associated with that disruptor element displacement increment are the same for that complementary pair. In some such embodiments, the receive coil section is characterized in that each complementary pair CPi includes an upper rotation detection coil TRSCi and a lower rotation detection coil BRSCi, the shapes of whose internal areas nominally coincide when projected along the axial direction. The particular embodiment of the stylus position detection section 511′ shown in FIG. 5 may be found to be consistent with this specification. However, it will be understood that various configurations of complementary pairs may be used, and the particular configuration shown in FIG. 5 is illustrative only and not limiting.

[0056] In some embodiments, the receive coil section (e.g., 570) and disruptor element (e.g., 551) may be configured such that the disruptor element includes at least N straight sides, and for any respective complementary pair CPi, each one of the disruptor element's straight sides intersects both the upper rotation detection coil TRSCi and the lower rotation detection coil BRSCi of that respective complementary pair. In some such embodiments, N=4, and the at least N straight sides include four sides arranged parallel to the sides of a rectangle or square. The particular embodiment of the stylus position detection section 511′ shown in FIG. 5 may be found to be consistent with this specification. However, it will be understood that various combinations of complementary pair configurations and disruptor element edge configurations may be used, and the particular configuration combination shown in FIG. 5 is illustrative only and not limiting.

[0057] FIG. 6 is a partial, schematic isometric view of certain elements of the stylus position detection unit 511′ shown in FIG. 5 , including a schematic representation of connections CONN to a block diagram of one exemplary embodiment of a signal processing and control circuit 680. As shown in FIG. 6 , the signal processing and control circuit 680 is operatively connected to the various coils of the stylus position detection unit 511′. In the embodiment shown in FIG. 6 , the signal processing and control circuit 680 includes a digital controller / processor 681, which may regulate various timing and signal connection or exchange operations between its various interconnected components, including a drive signal generator 682, an amplifier / switching unit 683, a sample and hold unit 684, a multiplexing unit 685, and an A / D conversion unit 686. The digital controller / processor 681 may perform various digital signal processing operations to determine the output signals APSOut and RPSOut, as outlined above with reference to FIG. 2 and further described below. The design and operation of the signal processing and control circuit 680 may generally be recognized and understood by those skilled in the art in accordance with known principles. For example, in one embodiment, certain elements of the signal processing and control circuitry 680 may be designed and operated by analogy with corresponding elements disclosed in U.S. Pat. No. 5,841,274, which is incorporated herein by reference in its entirety.

[0058] During operation, drive signal generator 682 operates to provide a varying coil drive signal Dsig (e.g., pulses) to field-generating coil arrangement 560, which, in response to the coil drive signal, generates a varying magnetic flux generally along the axial direction within disruptor movement volume MV. In the configuration shown, upper field-generating coil 561T and lower field-generating coil 561B are configured to provide mutually reinforcing varying magnetic fluxes. Amplifier / switching section 683 is configured to input signals RSIG and ASIG from receive coil section 570, which include respective signal components provided by the respective rotational and axial detection coils located on the upper and lower coil substrates (e.g., signal components SIGTASCC, SIGBASCC, SIGTRSC1-SIGTRSC4, and SIGBRSC1-SIGBRSC4, as outlined above). In some embodiments, amplifier / switching section 683 may include switching circuitry capable of combining various analog signals (e.g., via appropriate serial or parallel connections, etc.) to provide various desired sum or difference signals, as defined by relationships such as those shown in Equations 5-7. However, in other embodiments, amplifier / switching section 683 may perform only amplification and signal conditioning operations (e.g., possibly signal inversion operations), with all signal combining operations being performed by other circuit portions.

[0059] The sample and hold unit 684 receives the various analog signals from the amplifier / switching unit 683 and performs sample and hold operations according to known principles, e.g., simultaneously sampling and holding all respective signal components arising from the various respective detection coils of the receive coil unit 570. In one embodiment, the multiplexing unit 685 may couple the various signals to the A / D converter unit 686 sequentially and / or in combinations related to various desired signal relationships (e.g., as defined by the relationships shown in Equations 5-7, etc.). The A / D converter unit 686 outputs corresponding digital signal values ​​to the digital controller / processor 681.

[0060] The digital controller / processor 681 may then process and / or combine the digital signal values ​​according to various desired relationships (e.g., as defined in Equations 5-7, etc.) to determine and output output signals APSOut and RPSOut, which indicate the axial and rotational position of at least one of the disruptor element 551 or the stylus 506 relative to the frame or housing of the scanning probe. In some embodiments, the digital controller / processor 681 may be configured such that the output signals APSOut and RPSOut directly indicate the three-dimensional position of the stylus 506 or its probe tip 548 relative to the frame of the scanning probe. In other embodiments, the digital controller / processor 681 may be configured to output signals that indirectly indicate the three-dimensional position of the stylus 506 or its probe tip 548 relative to the frame of the scanning probe, and a host system (e.g., a CMM) may input such signals and perform additional processing to further combine or refine such signals to determine the three-dimensional position of the stylus 506 or its probe tip 548 relative to the overall coordinate system used for scanning probe and / or CMM measurement.

[0061] FIG. 7 is an illustration of a graph 700 including a signal curve 710 of output signal level (i.e., on a scale in volts, as shown on the vertical axis, ranging from −2 volts to +2 volts) versus X / Y probe tip position (i.e., on a scale in millimeters, as shown on the horizontal axis at the bottom of the graph, ranging from −2 mm to +2 mm). For example, in one embodiment, signal curve 710 may correspond to a Y probe tip position, as described above with respect to the example of FIG. 3, and the signal level may correspond to signals (e.g., combined and / or processed signals) from rotational detection coils TRSC1, TRSC2, BRSC1, and BRSC2. In such an embodiment, a similar second graph 700 may correspond to an X probe tip position, such as those in the examples of FIGS. 5 and 6, and the signal level may correspond to signals (e.g., combined and / or processed signals) from rotational detection coils TRSC3, TRSC4, BRSC3, and BRSC4.

[0062] Also shown in Figure 7 is a representation of the corresponding U / V element positions (e.g., disruptor element positions as shown in the examples of Figures 2-6) (i.e., on a scale in degrees, ranging from -1.8 degrees to +1.8 degrees, as shown on the horizontal axis at the top of the graph). As shown, signal curve 710 includes signal curve portions 712, 714, and 716, which correspond to respective operating regions RE1, RE2, and RE3. Referring to graph 700 from left to right, signal curve portion 712 extends from a start point P1A to an end point P1B, signal curve portion 714 extends from a start point P2A to an end point P2B, and signal curve portion 716 extends from a start point P3A to an end point P3B. 7, end point P1B and start point P2A are nominally the same, and end point P2B and start point P3A are nominally the same (e.g., showing that signal curve 710 is nominally continuous with respect to the transitions between signal curve portions 712, 714, and 716 and between corresponding operating regions RE1, RE2, and RE3). In various embodiments, signal curve portion 712 extends across an operating range OPR and a signal range SGR (e.g., corresponding to the operating range and signal range of signal processing and control circuitry 680), which may additionally or alternatively be referred to as an active operating range OPR and an active signal range SGR in various embodiments.

[0063] Each point corresponds to a respective output signal level and X / Y probe tip position (and U / V component position). In various embodiments, the points may be referenced according to their respective coordinate values ​​on the graph 700. For example, the starting point P2A has coordinates (PTP P2A , SIG P2A ), and the end point P2B may be referred to as being at coordinates (PTP P2B , SIG P2B ) as some specific numerical examples. In one embodiment, as shown in FIG. P2A =-1.67mm, SIG P2A =-1.75 volts, PTP P2B=1.67mm, and SIG P2B =1.75 volts. Alternatively or in addition to the probe tip position PTP, one may also refer to the element position EP, and EP P2A =-1.5 degrees and EP P2B =1.5 degrees.

[0064] Note that the central operating region RE2, which may additionally or alternatively be referred to as the central high-gain operating region RE2, extends across the X / Y probe tip position range R2 and has a corresponding signal range S2. In various embodiments, the probe tip and signal range may also be referred to as corresponding to the difference between the start point P2A and the end point P2B of the corresponding signal curve portion 714 (e.g., R2 = PTP P2B -PTP P2A and S2=SIG P2B -SIG P2A ). In various embodiments, the gain of a signal curve portion and / or corresponding operating region may correspond to (e.g., may be defined as) a ratio of an output change (e.g., a change in output signal corresponding to the magnitude of the signal range of the operating region) to an input change (e.g., a change in probe tip position or a change in element position corresponding to the range of probe tip positions and / or the range of element positions of the operating region). In such embodiments, if gain GN2 corresponds to the gain of operating region RE2, then gain GN2 = S2 / R2 = (SIG P2B -SIG P2A / (PTP P2B -PTP P2A ) = 3.5 Volts / 3.33 mm = 1.05 Volts / mm (i.e., according to the exemplary numbers above, where PTP relates to the probe tip position). Additionally, gain GN2 = S2 / R2 = (SIG P2B -SIG P2A / (EP P2B -EP P2A)=3.5 volts / 3.0 degrees=1.167 volts / degree (i.e., according to the example numbers above, where EP relates to element position). In various embodiments, the central operating region RE2 and the center point CEN of signal curve portion 714 (which may also correspond to the center point of signal curve 710, for example) are located at the center of SIG CEN = 0 volts, PTP CEN =0mm, EP CEN = 0 degrees. In the example of Figure 7, range R2 may also correspond to operating range OPR, and corresponding signal range S2 may correspond to signal range SGR.

[0065] In contrast to the central high-gain operating region RE2 (i.e., having a non-zero gain GN2), operating regions RE1 and RE3 may also be referred to as saturated operating regions RE1 and RE3 corresponding to saturation conditions (e.g., of amplifier / switching section 683 in FIG. 6 ) and correspondingly depicted as having no gain (i.e., correspondingly referred to herein as saturation regions rather than gain regions). More specifically, corresponding signal curve portions 712 and 716 are depicted as nominally flat, exhibiting no gain, and further alteration of the X / Y probe tip position when operating in these saturated operating regions does not result in any significant increase or decrease in output signal level. Similar saturated operating regions are depicted in FIGS. 8-10 (described in more detail below) and will be understood to have similar characteristics.

[0066] Note that in the configuration of FIG. 7 , with a fixed probe gain, the output signal (i.e., corresponding to the sensor component output) is linear over the entire probe range until saturation is reached (e.g., as shown in signal curve portion 714 relative to signal curve portions 712 and 716). In various embodiments, such a configuration may be characterized as achieving the full mechanical range at the expense of resolution. Note that, in accordance with the principles disclosed herein, the full measurement range may be utilized as shown in the example of FIG. 7 , but the true useful measurement range (e.g., corresponding to the primarily utilized measurement range) may be much lower. As described in more detail below with respect to FIGS. 8-10 , higher resolution and better noise performance may be achieved by using a higher gain in the primarily utilized measurement range (e.g., corresponding to the central high-gain operating region). Note that if a high gain is subsequently used for measurements outside the primarily utilized measurement range, this will cause the sensor component output to saturate before reaching the end of the mechanical range (e.g., as will be understood with respect to the configurations of FIGS. 3-6 above). By varying the gain based on measurement position in accordance with the principles disclosed herein, greater accuracy may be achieved in the primarily utilized measurement range while avoiding saturation across the entire range. More specifically, as described in more detail below with respect to the examples of FIGS. 8-10, as the output signal of the sensor arrangement approaches saturation, the gain may be reduced to return the output signal to a desired level. In various embodiments, such a process may be repeated at set intervals until the maximum range or minimum desired gain is reached. As further described below with respect to a comparison of the examples of FIGS. 8 and 10, gain bands (i.e., corresponding to operating regions) may be programmed / determined based on the length of the stylus to maximize signal across the region of interest and prevent saturation across the entire mechanical range.

[0067] FIG. 8 is a diagram of a graph 800 including a signal curve 810 of output signal level (i.e., in volts) versus X / Y probe tip position (i.e., in millimeters) and U / V element position (i.e., in degrees), each shown on a scale similar to that of FIG. 7. In various embodiments, the ranges shown in FIG. 8 are configured for use with a stylus (e.g., stylus 406 / 506) of a particular length (e.g., 20 mm length in this example). As shown and described above with respect to FIGS. 3-6, an element (e.g., disruptor element 451 / 551) may have a particular maximum range of travel (e.g., within the position sensing arrangement), which may correspond to a particular maximum range of travel of the probe tip (e.g., probe tip 448 / 548) according to the length of the stylus (e.g., relative to the center of rotation RC and according to calculations such as Equations 1-3). As described in more detail below with respect to FIG. 10, in various embodiments, different ranges may be configured for use with styluses of different lengths.

[0068] As shown, signal curve 810 includes signal curve portions 812, 814, 816, 818, 820, 822, and 824 corresponding to respective operating regions RE1, RE2, RE3, RE4, RE5, RE6, and RE7. In left-to-right reference to graph 800, each of the signal curve portions extends from a corresponding start point to a corresponding end point (e.g., similar to FIG. 7). More specifically, signal curve portion 812 extends from a starting point P1A to an ending point P1B, signal curve portion 814 extends from a starting point P2A to an ending point P2B, signal curve portion 816 extends from a starting point P3A to an ending point P3B, signal curve portion 818 extends from a starting point P4A to an ending point P4B, signal curve portion 820 extends from a starting point P5A to an ending point P5B, signal curve portion 822 extends from a starting point P6A to an ending point P6B, and signal curve portion 824 extends from a starting point P7A to an ending point P7B. As described in more detail below, the slopes of signal curve portions 812, 814, 816, 818, 820, 822, and 824 indicate corresponding operating regions RE1, RE2, RE3, RE4, RE5, RE6, and RE7.

[0069] In the example of Figure 8, end point P2B is not the same as start point P3A, end point P3B is not the same as start point P4A, end point P4B is not the same as start point P5A, and end point P5B is not the same as start point P6A. These differences indicate signal level changes (e.g., discontinuities or abrupt signal transitions) at the transitions between signal curve portions 814, 816, 818, 820, and 822 and corresponding operating regions RE2, RE3, RE4, RE5, and RE6. Similar to the discussion above with respect to Figure 7, each point corresponds to a respective output signal level and X / Y probe tip position (and U / V element position) and may be referenced according to its respective coordinate value on graph 800.

[0070] 8, operating region RE4, which may be referred to as central high-gain operating region RE4, extends across and corresponds to X / Y probe tip position range R4, which may also be referred to as central high-gain probe tip position range R4, and has a corresponding signal range S4. In various embodiments, the probe tip and signal range may also be referenced as corresponding to the difference between the start point P4A and the end point P4B of the corresponding signal curve portion 818 (e.g., R4=PTP P4B -PTP P4A and S4=SIG P4B -SIG P4A ) In accordance with the above definition, the corresponding gain is (i.e., according to the example values ​​shown in graph 800, as indicated by the corresponding slope of signal curve portion 818): GN4 = S4 / R4 = |(SIG P4B -SIG P4A )| / (PTP P4B -PTP P4A )=2.66 volts / 0.667 mm=4.0 volts / mm (i.e., according to the example values ​​shown in graph 800, as shown by the corresponding slope of signal curve portion 818).

[0071] In various embodiments, ranges R1-R7 of operating regions RE1-RE7 may additionally or alternatively be referred to as element position ranges R1-R7 (e.g., in relation to corresponding angular U / V element positions, such as the disruptor element positions shown in the examples of FIGS. 2-6). Similar to the discussion above for the example operating region RE4, element positions and signal ranges may also be referred to as corresponding to the difference between the start point P4A and the end point P4B of the corresponding signal curve portion 818 (e.g., R4=EP P4B -EP P4A and S4=SIG P4B -SIG P4A ), where EP denotes element position. Similar to the probe tip position example above, for element position, the corresponding gain is GN4 = S4 / R4 = |(SIG P4B -SIG P4A )| / (EP P4B -EP P4A ) = 2.66 volts / 0.6 degrees = 4.44 volts / degree. Range R4 may additionally or alternatively be referred to as a central high-gain element position range R4. In various embodiments, central operating region RE4 and center point CEN of signal curve portion 818 (which may, for example, correspond to the center point of signal curve 810) are located at SIG CEN = 0 volts, PTP CEN =0mm, EP CEN = 0 degrees. In various embodiments, when the center point CEN does not have one or more values ​​corresponding to 0, a zeroing operation may be performed, which is described in more detail below.

[0072] In various embodiments, operating regions RE3 and RE5 may be referred to as a first pair of lower gain operating regions FP, with the central high-gain operating region RE4 being between the first pair of lower gain operating regions RE3 and RE5. As shown in FIG. 8 , each of the lower gain operating regions RE3 and RE5 of the first pair of lower gain operating regions FP is adjacent to a respective side of the central high-gain operating region RE4. More specifically, operating region RE3 is adjacent to the left side of the central high-gain operating region RE4, and operating region RE5 is adjacent to the right side of the central high-gain operating region RE4. In various embodiments, the central high-gain operating region RE4 may additionally or alternatively be said to be bounded by the first pair of lower gain operating regions FP. In various embodiments, operating region RE3 may additionally or alternatively be described as a first negative relative position operating region, and operating region RE5 as a first positive relative position operating region of the first pair of lower gain operating regions FP (e.g., the relative negative and positive positions may be associated / related to a null or zero position at or near the center of the central high gain operating region RE4, as shown by an XY probe tip position of 0 in graph 800 and / or as corresponding to center point CEN). In various embodiments, each of the lower gain operating regions RE3 and RE5 of the first pair of lower gain operating regions FP may have a corresponding gain (e.g., gains GN3 and GN5) that is smaller than the gain (e.g., gain GN4) of the central high gain operating region RE4.

[0073] 8, the operating region RE3 extends over and corresponds to an X / Y probe tip position range R3, which may be referred to as a lower gain probe tip position range R3, and has a corresponding signal range S3. As noted above, the probe tip and signal range may also be referred to as corresponding to the difference between the start point P3A and the end point P3B of the corresponding signal curve portion 816 (e.g., R3=PTP P3B -PTP P3A and S3=SIG P3B -SIG P3A) according to the above definition, the corresponding gain is (i.e., according to the example values ​​shown in graph 800, as indicated by the corresponding slope of signal curve portion 816): GN3 = S3 / R3 = |(SIG P3B -SIG P3A )| / (PTP P3B -PTP P3A ) = 1.00 Volts / 0.667 mm = 1.5 Volts / mm. Furthermore, in relation to the element position calculations above, the gain is (i.e., according to the example values ​​shown in graph 800, as shown by the corresponding slope of signal curve portion 816): GN3 = S3 / R3 = |(SIG P3B -SIG P3A )| / (EP P3B -EP P3A ) = 1.00 volts / 0.6 degrees = 1.67 volts / degree.

[0074] 8, the operating region RE5 extends over and corresponds to an X / Y probe tip position range R5, which may be referred to as a lower gain probe tip position range R5, and has a corresponding signal range S5. As noted above, the probe tip and signal range may also be referred to as corresponding to the difference between the start point P5A and the end point P5B of the corresponding signal curve portion 820 (e.g., R5=PTP P5B -PTP P5A and S5=SIG P5B -SIG P5A ) In accordance with the above definition, the corresponding gain is (i.e., according to the example values ​​shown in graph 800, as indicated by the corresponding slope of signal curve portion 820): GN5=S5 / R5=|(SIG P5B -SIG P5A )| / (PTP P5B -PTP P5A ) = 1.00 Volts / 0.667 mm = 1.5 Volts / mm. Furthermore, in relation to the element position calculations above, the gain is, i.e., GN5 = S5 / R5 = |(SIG P5B -SIG P5A )| / (EP P5B-EP P5A ) = 1.00 volts / 0.6 degrees = 1.67 volts / degree.

[0075] Thus, in these examples, the gain GN4 of the central high-gain operating region RE4 is greater than the gains GN3 and GN5 of the lower gain operating regions RE3 and RE5, respectively, of the first pair of lower gain operating regions FP (i.e., GN4 = 4.0 volts / mm and 4.44 volts / degree, which is greater than GN3 = GN5 = 1.5 volts / mm and 1.67 volts / degree). Note that these relationships are also illustrated by the slope of signal curve portion 818 compared to the slopes of signal curve portions 816 and 820. Note that the slopes and positions of signal curve portions 816 and 820 also indicate a desirable symmetrical and balanced configuration (e.g., signal curve portions 816 and 820 are collinear within operating range OPR, with position ranges R3 and R5 equal, signal ranges S3 and S5 equal, and distances from the center and edges of graph 800 equal, etc.). While such characteristics may be desirable in some embodiments, it will be understood that certain alternative embodiments may include configurations having different characteristics (e.g., such alternative configurations may not be symmetrical).

[0076] In various embodiments, the operating regions RE2 and RE6 may be referred to as the lower gain operating region SP of the second pair, and the operating regions RE3 and RE5 of the lower gain operating region FP of the first pair are between the operating regions RE2 and RE6 of the lower gain operating region SP of the second pair. As shown in FIG. 8 , each of the lower gain operating regions RE2 and RE6 of the lower gain operating region SP of the second pair is adjacent to the outside of the operating region RE3 or RE5 of the lower gain operating region FP of the first pair, respectively. More specifically, the operating region RE2 of the lower gain operating region SP of the second pair is adjacent to the left side of the operating region RE3 of the lower gain operating region FP of the first pair, and the operating region RE6 of the lower gain operating region SP of the second pair is adjacent to the right side of the operating region RE5 of the lower gain operating region FP of the first pair. In various embodiments, the lower gain operating region FP of the first pair may additionally or alternatively be described as being bounded by the lower gain operating region SP of the second pair. In various embodiments, operating region RE2 may additionally or alternatively be described as a second negative relative position operating region, and operating region RE6 may additionally or alternatively be described as a second positive relative position operating region of the second pair of lower gain operating regions SP (e.g., the relative negative and positive positions may be associated / related to a null or zero position at or near the center / centre of the central high-gain operating region RE4, as shown by an XY probe tip position of 0 in graph 800 and / or as corresponding to center point CEN). In various embodiments, operating regions RE2 and RE6 of the second pair of lower gain operating regions SP may each have a corresponding gain (e.g., gains GN2 and GN6) that is smaller than the corresponding gains (e.g., gains GN3 and GN5) of operating regions RE3 and RE5 of the first pair of lower gain operating regions FP.

[0077] 8, the operating region RE2 extends over and corresponds to an X / Y probe tip position range R2, which may be referred to as a lower gain probe tip position range R2, and has a corresponding signal range S2. As noted above, the probe tip and signal range may also be referred to as corresponding to the difference between the start point P2A and the end point P2B of the corresponding signal curve portion 814 (e.g., R2=PTP P2B -PTP P2A and S2=SIG P2B -SIG P2A ). According to the above definition, the corresponding gain is GN2=S2 / R2=|(SIG P2B -SIG P2A )| / (PTP P2B -PTP P2A ) = 0.75 Volts / 0.667 mm = 1.125 Volts / mm (i.e., according to the example values ​​shown in graph 800, as shown by the corresponding slope of signal curve portion 814). Furthermore, in relation to the element position calculation above, (i.e., according to the example values ​​shown in graph 800, as shown by the corresponding slope of signal curve portion 814), gain GN2 = S2 / R2 = |(SIG P2B -SIG P2A )| / (EP P2B -EP P2A ) = 0.75 volts / 0.6 degrees = 1.25 volts / degree.

[0078] 8, the operating region RE6 extends over and corresponds to an X / Y probe tip position range R6, which may be referred to as a lower gain probe tip position range R6, and has a corresponding signal range S6. As noted above, the probe tip and signal range may also be referred to as corresponding to the difference between the start point P6A and the end point P6B of the corresponding signal curve portion 822 (e.g., R6=PTP P6B -PTP P6A and S6=SIG P6B -SIG P6A) according to the above definition, the corresponding gain is (i.e., according to the example values ​​shown in graph 800, as indicated by the corresponding slope of signal curve portion 822): GN6 = S6 / R6 = |(SIG P6B -SIG P6A )| / (PTP P6B -PTP P6A ) = 0.75 volts / 0.667 mm = 1.125 volts / mm. Furthermore, in relation to the element position calculations above, the gain is (i.e., according to the example values ​​shown in graph 800, as shown by the corresponding slope of signal curve portion 822): GN6 = S6 / R6 = |(SIG P6B -SIG P6A )| / (EP P6B -EP P6A ) = 0.75 volts / 0.6 degrees = 1.25 volts / degree.

[0079] Thus, in these examples, the gains GN3 and GN5 in the lower gain operating region FP of the first pair are greater than the gains GN2 and GN6 in the lower gain operating region SP of the second pair (i.e., GN3 = GN5 = 1.5 Volts / mm and 1.67 Volts / degree, which is greater than GN2 = GN6 = 1.125 Volts / mm and 1.25 Volts / degree). Note that these relationships are also illustrated by the slopes of signal curve portions 816 and 820 compared to the slopes of signal curve portions 814 and 822. Note that the slopes and positions of signal curve portions 814 and 822 also indicate a desirable symmetrical and balanced configuration (e.g., equal probe tip position ranges R2 and R6, equal signal ranges S2 and S6, and equal distances from the center and edges of graph 800 within operating range OPR, etc.).

[0080] In various embodiments, the operating regions RE1 and RE7 may be referred to as a pair of saturated operating regions TP (e.g., or a third pair of operating regions TP), with the operating regions RE2 and RE6 of the second pair of lower gain operating regions SP being between the operating regions RE1 and RE7 of the pair of saturated operating regions TP. As shown in FIG. 8 , each of the operating regions RE1 and RE7 of the pair of saturated operating regions TP is adjacent to the outside of the operating region RE4 or RE6 of the second pair of lower gain operating regions SP, respectively. More specifically, the operating region RE1 of the pair of saturated operating regions TP is adjacent to the left of the operating region RE2 of the second pair of lower gain operating regions SP, and the operating region RE7 of the pair of saturated operating regions TP is adjacent to the right of the operating region RE6 of the second pair of lower gain operating regions SP. In various embodiments, the second pair of lower gain operating regions SP may additionally or alternatively be described as being bounded by the pair of saturated operating regions TP. In various embodiments, operating region RE1 may additionally or alternatively be described as a third negative relative position operating region and operating region RE7 as a third positive relative position operating region of the pair of saturation operating regions TP (e.g., the relative negative and positive positions may be associated / related to a null or zero position at or near the center / centre of central high gain operating region RE4, as shown by an XY probe tip position of 0 in graph 800 and / or as corresponding to center point CEN).

[0081] Note that the pair of saturated operating regions TP, operating regions RE1 and RE7, correspond to respective saturated probe tip position ranges R1 and R7 (e.g., R1 may be equal to R7) and are at the ends of graph 800 (e.g., as corresponding to the ends of the operating range OPR of the signal processing and control circuitry). As noted above, the pair of saturated operating regions TP correspond to saturated conditions where there is no change in output signal due to changes in probe tip position and no corresponding gain. More specifically, the corresponding signal curve portions 812 and 824 are shown to be nominally flat, with no gain indicated, and further changes in X / Y probe tip position when operating in these saturated operating regions do not result in any increase or decrease in output signal level.

[0082] In various embodiments, the gain signal curve portions 814, 816, 818, 820, and 822 of signal curve 810 (i.e., between saturated signal curve portions 812 and 824) extend over an operating range OPR and a signal range SGR (e.g., corresponding to the operating range and signal range of signal processing and control circuitry 680), which may additionally or alternatively be referred to in various embodiments as an active operating range OPR and an active signal range SGR. In the example of FIG. 8, SGR=SIG P6B -SIG P2A = 3.75 volts, and OPR PTP =PTP P6B -PTP P2A = 3.33 mm, OPR EP =EP P6B -EP P2A = 3 degrees. In various embodiments, the full range of signal curve 810 (i.e., including saturated signal curve portions 812 and 824) may correspond to the full mechanical range (e.g., of the probe's detection configuration), which may be achieved by adjusting the PTP, as shown. P7B -PTP P1A = 4.0 mm, EP P7B -EP P1A =3.6 degrees.

[0083] In various embodiments, to achieve a transition between operating regions RE1-RE7 of FIG. 8 , and in the configurations of FIGS. 9 and 10 as described in more detail below, a transition operation may be performed (e.g., adjusting the gain to correspond to that of the operating region being transitioned to). In one embodiment, the transition operation may include adjusting the power of a field-generating coil arrangement (e.g., field-generating coil arrangement 560) to adjust the ratio of the magnitude of the change in output signal to the change in probe tip position to correspond to the specified gain of the operating region being transitioned to. In various embodiments, the power may be adjusted by adjusting the coil drive signal (e.g., from drive signal generator 682). It will be appreciated that such techniques can achieve large signal changes (e.g., large signal increases with little or no corresponding noise increase) and can be implemented without the need to add new components to existing probe configurations, etc.

[0084] In another embodiment, the transitioning operation may include adjusting one or more variable gain amplifiers to adjust the ratio of the magnitude of the change in output signal to the change in probe tip position to correspond to a specified gain of the operating region being transitioned. For example, in various embodiments, the amplifier / switching unit 683 may include one or more variable gain amplifiers configured to amplify the signal from the coil of the stylus position detector, which may be adjusted accordingly. It will be appreciated that such techniques may have a negligible impact on power and may be implemented without the need to add new components to existing probe configurations, etc.

[0085] In another embodiment, the transition operation may include modifying the characteristics of one or more detection coils (e.g., rotational detection coils) to adjust the ratio of the magnitude of the change in output signal to the change in probe tip position to correspond to the specified gain of the operating region being transitioned. For example, in various embodiments, a relay or other form of switch may be utilized to add or remove turns from the coil (e.g., to effectively change the coil size) or otherwise modify the characteristics of the detection coil to achieve the specified gain change. It will be appreciated that such techniques may have a negligible impact on power and may allow the sensor configuration to be optimized for each new gain step / transition.

[0086] In another embodiment, the transition operation may include changing the input range of the analog-to-digital converter to adjust the ratio of the magnitude of the change in output signal to the change in probe tip position to correspond to the specified gain of the operating region being transitioned. For example, in various embodiments, the A / D converter 686 may include one or more analog-to-digital converters, or a single analog-to-digital converter with a variable range, configured to convert the analog signal from the stylus position detector coil to a digital signal, and the input range may be changed. Such a change may allow a smaller range to be used for the main measurement envelope to increase resolution. It will be understood that such a technique may have only a negligible impact on power.

[0087] FIG. 9 is an illustration of a graph 900 including a signal curve 910 of output signal level (i.e., in volts) versus Z probe tip position (i.e., in millimeters). In the example of FIG. 9, graph 900 is substantially similar to graph 800, and will be understood to have similar characteristics and similar operation, as will be understood from the above description of the corresponding features of graph 800. The primary difference from graph 800, which relates to X / Y probe tip position (e.g., related to rotational movement and rotational detection coils, etc., as described above with respect to FIGS. 2-6), is that graph 900 relates to Z probe tip position (e.g., related to axial movement and axial detection coil configuration, etc., as described above with respect to FIGS. 2-6). Graph 900 also correspondingly does not include a scale for angular U / V component position (i.e., related to rotational movement). 10, when styli of different lengths are utilized, alternative operating characteristics may be utilized for X / Y probe tip position measurements (e.g., because different stylus lengths result in different corresponding amounts of movement of U / V element positions, such as movement of disruptor element 551, for a given amount of probe tip movement). In contrast, for Z probe tip position measurements (e.g., where stylus length may not typically be a significant factor), the same operating characteristics may be utilized for styli of any length with respect to Z movement, and thus, in various embodiments, graph 900 may represent such operating characteristics for Z probe tip position measurements for styli of any length.

[0088] As shown in FIG. 9 , signal curve 910 includes signal curve portions 912, 914, 916, 918, 920, 922, and 924 (e.g., which look similar to and exhibit the same behavior as signal curve portions 812, 814, 816, 818, 820, 822, and 824 of FIG. 8 ), which correspond to respective operating regions RE1, RE2, RE3, RE4, RE5, RE6, and RE7. Briefly, similar to FIG. 8 , for signal curve portion 918, the central high-gain operating region RE4 corresponds to the central high-gain probe tip position range R4. Signal curve portions 916 and 920 correspond to a first pair of lower-gain operating regions FP, which correspond to respective lower-gain probe tip position ranges R3 and R5. The central high-gain operating region RE4 lies between the operating regions RE3 and RE5 of the first pair of lower-gain operating regions FP. The first pair of lower gain operating regions FP have respective gains GN3 and GN5 that are lower than the gain GN4 of the central high-gain operating region RE4 (e.g., as indicated by the slope of the respective signal curve portions 916 and 920 compared to signal curve portion 918), with gain and other values ​​identical to those described above with respect to FIG. 8 (e.g., GN4=4.0 volts / mm, and GN3=GN5=1.5 volts / mm greater).

[0089] Signal curve portions 914 and 922 correspond to a second pair of lower gain operating regions SP, corresponding to respective lower gain probe tip position ranges R2 and R6. The operating regions RE3 and RE5 of the first pair of lower gain operating regions FP are between the operating regions RE2 and RE6 of the second pair of lower gain operating regions SP. The second pair of lower gain operating regions SP have lower gains GN2 and GN6, respectively, than the gains GN3 and GN5 of the first pair of lower gain operating regions FP (e.g., as indicated by the slopes of the respective signal curve portions 914 and 922 compared to signal curve portions 916 and 920), with gain and other values ​​identical to those described above with respect to FIG. 8 (e.g., GN3 = GN5 = 1.5 volts / mm, and GN2 = GN6 = 1.125 volts / mm). Signal curve portions 912 and 924 correspond to a pair of saturated operating regions TP, which correspond to respective saturated probe tip position ranges and are at the ends of the operating range OPR of the signal processing and control circuitry. A second pair of lower gain operating regions SP lies between the pair of saturated operating regions TP, which correspond to a saturated state where there is no change in output signal due to changes in probe tip position and no corresponding gain.

[0090] 10 is an illustration of a graph 1000 including a signal curve 1010 of output signal level (i.e., in volts) versus X / Y probe tip position (i.e., in millimeters), and also U / V element position (i.e., in degrees). In various embodiments, the ranges shown in FIG. 10 are configured for use with a stylus (e.g., stylus 406 / 506) of a particular length (e.g., 100 mm length in this example). As shown and described above with respect to FIGS. 3-6, an element (e.g., disruptor element 451 / 551) may have a particular maximum range of travel (e.g., within the position sensing arrangement), which may correspond to a particular maximum range of travel of the probe tip (e.g., probe tip 448 / 548) according to the length of the stylus (e.g., relative to the center of rotation RC and according to calculations such as Equations 1-3). In the example of FIG. 10 , except for certain differences relating to certain different ranges that will be explained in more detail below, graph 1000 will be understood to include certain characteristics similar to those of graph 800 and to have certain similar behaviors that will be understood from the above description of the corresponding features of graph 800.

[0091] As shown in FIG. 10 , signal curve 1010 includes signal curve portions 1012, 1014, 1016, 1018, 1020, 1022, and 1024 (e.g., which have certain different ranges but otherwise operate similarly to signal curve portions 812, 814, 816, 818, 820, 822, and 824 of FIG. 8 ), which correspond to respective operating regions RE1, RE2, RE3, RE4, RE5, RE6, and RE7. As in FIG. 8 , for signal curve portion 1018 of FIG. 10 , the central high-gain operating region RE4 corresponds to the central high-gain probe tip position range R4. (i.e., as shown by the corresponding slope of signal curve portion 1018, according to the example values ​​shown in graph 1000) Gain GN4 = S4 / R4 = |(SIG P4B -SIG P4A )| / (PTP P4B -PTP P4A) = 2.66 Volts / 0.667 mm = 4.0 Volts / mm. Also, the gain GN4 = S4 / R4 = |(SIG P4B -SIG P4A )| / (EP P4B -EP P4A ) = 2.66 volts / 0.3 degrees = 8.88 volts / degree. Range R4 may additionally or alternatively be referred to as a central high gain element position range R4. In various embodiments, central operating region RE4 and center point CEN of signal portion 1018 (which may correspond, for example, to the center point of signal curve 1010) are located at SIG CEN = 0 volts, PTP CEN =0mm, EP CEN = 0 degrees. In various embodiments, when the center point CEN does not have one or more values ​​corresponding to 0, a zeroing operation may be performed, which is described in more detail below.

[0092] Signal curve portions 1016 and 1020 correspond to a first pair of lower gain operating regions FP, which correspond to respective lower gain probe tip position ranges R3 and R5. A central high-gain operating region RE4 lies between operating regions RE3 and RE5 of the first pair of lower gain operating regions FP. The first pair of lower gain operating regions FP have respective gains GN3 and GN5 that are lower than the gain GN4 of the central high-gain operating region RE4 (e.g., as indicated by the slope of respective signal curve portions 1016 and 1020 compared to signal curve portion 1018).

[0093] More specifically, gain GN3=S3 / R3=|(SIG P3B -SIG P3A )| / (PTP P3B -PTP P3A) = 1.00 Volts / 1.33 mm = 0.75 Volts / mm. Furthermore, in relation to the element position calculations above, the gain is (i.e., according to the example values ​​shown in graph 1000, as shown by the corresponding slope of signal curve portion 1016): GN3 = S3 / R3 = |(SIG P3B -SIG P3A )| / (EP P3B -EP P3A ) = 1.00 Volts / 0.6 degrees = 1.67 Volts / degree. Furthermore, (i.e., according to the example values ​​shown in graph 1000, as shown by the corresponding slope of signal curve portion 1020), gain GN5 = S5 / R5 = |(SIG P5B -SIG P5A )| / (PTP P5B -PTP P5A ) = 1.00 Volts / 1.33 mm = 0.75 Volts / mm. Furthermore, in relation to the element position calculations above, the gain is (i.e., according to the example values ​​shown in graph 1000, as shown by the corresponding slope of signal curve portion 1020): GN5 = S5 / R5 = |(SIG P5B -SIG P5A )| / (EP P5B -EP P5A ) = 1.00 volts / 0.6 degrees = 1.67 volts / degree.

[0094] Thus, in these examples, the gain GN4 of the central high-gain operating region is greater than the gains GN3 and GN5 of the lower gain operating regions RE3 and RE5, respectively, of the first pair of lower gain operating regions FP (i.e., GN4 = 4.0 volts / mm and 8.88 volts / degree, which is greater than GN3 = GN5 = 0.75 volts / mm and 1.67 volts / degree). Note that these relationships are also illustrated by the slope of signal curve portion 1018 compared to the slopes of signal curve portions 1016 and 1020. Note that the slopes and positions of signal curve portions 1016 and 1020 also indicate a desirable symmetrical and balanced configuration (e.g., equal position ranges R3 and R5, equal signal ranges S3 and S5, and equal distances from the center and edges of graph 1000 within operating range OPR, etc.).

[0095] Signal curve portions 1014 and 1022 correspond to a second pair of lower gain operating regions SP, which correspond to respective lower gain probe tip position ranges R2 and R6. Operating regions RE3 and RE5 of the first pair of lower gain operating regions FP are between operating regions RE2 and RE6 of the second pair of lower gain operating regions SP. The second pair of lower gain operating regions SP have lower gains GN2 and GN6, respectively, than the gains GN3 and GN5 of the first pair of lower gain operating regions FP (e.g., as indicated by the slopes of signal curve portions 1014 and 1022, respectively, compared to signal curve portions 1016 and 1020).

[0096] More specifically, gain GN2=S2 / R2=|(SIG P2B -SIG P2A )| / (PTP P2B -PTP P2A ) = 0.75 volts / 1.33 mm = 0.5625 volts / mm. Furthermore, in relation to the element position calculation above, (i.e., according to the example values ​​shown in graph 1000, as shown by the corresponding slope of signal curve portion 1014), gain GN2 = S2 / R2 = |(SIG P2B -SIG P2A )| / (EP P2B -EP P2A ) = 0.75 volts / 0.6 degrees = 1.25 volts / degree. Furthermore, (i.e., according to the example values ​​shown in graph 1000, as shown by the corresponding slope of signal curve portion 1022), gain GN6 = S6 / R6 = |(SIG P6B -SIG P6A )| / (PTP P6B -PTP P6A ) = 0.75 volts / 1.33 mm = 0.5625 volts / mm. Furthermore, in relation to the element position calculations above, the gain is (i.e., according to the example values ​​shown in graph 1000, as shown by the corresponding slope of signal curve portion 1022): GN6 = S6 / R6 = |(SIGP6B -SIG P6A )| / (EP P6B -EP P6A ) = 0.75 volts / 0.6 degrees = 1.25 volts / degree.

[0097] Thus, in these examples, the gains GN3 and GN5 in the lower gain operating region FP of the first pair are greater than the gains GN2 and GN6 in the lower gain operating region SP of the second pair (i.e., GN3 = GN5 = 0.75 volts / mm and 1.67 volts / degree, which is greater than GN2 = GN6 = 0.5625 volts / mm and 1.25 volts / degree). Note that these relationships are also illustrated by the slopes of signal curve portions 1016 and 1020 compared to the slopes of signal curve portions 1014 and 1022. Note that the slopes and positions of signal curve portions 1014 and 1022 also indicate a desirable symmetrical and balanced configuration (e.g., signal curve portions 1014 and 1022 are collinear within operating range OPR, with position ranges R2 and R6 equal, signal ranges S2 and S6 equal, and distances from the center and edges of graph 1000 equal, etc.).

[0098] Signal curve portions 1012 and 1024 correspond to a pair of saturated operating regions TP, which correspond to respective saturated probe tip position ranges and are at the ends of the operating range OPR of the signal processing and control circuitry. A second pair of lower gain operating regions SP lies between the pair of saturated operating regions TP, which correspond to saturated conditions where there is no nominal change in output signal due to changes in probe tip position and nominal corresponding gain.

[0099] Note that the particular range in FIG. 10 contrasts with the particular range in FIG. 8, which is configured to be utilized with a different length stylus (e.g., a 20 mm long stylus in the example of FIG. 8 compared to a 100 mm long stylus in the example of FIG. 10). As one example, the X / Y probe tip position scale in graph 800 extends from −2 mm to +2 mm, while the X / Y probe tip position scale in graph 1000 extends from −4 mm to +4 mm. As another example, the operating range OPR (i.e., of gain signal curve portions 814, 816, 818, 820, and 822) is 3.33 mm in graph 800, while the operating range OPR (i.e., of gain signal curve portions 1014, 1016, 1018, 1020, and 1022) is 6.0 mm in graph 1000.

[0100] Note that the scale of the U / V element position is the same in each of graphs 800 and 1000, extending from -1.8 degrees to +1.8 degrees (e.g., as shown and described above with respect to Figures 3-6, the maximum range of movement of the disruptor element within the position detection arrangement may not change for different stylus lengths). Related to this aspect, to achieve a similar central high-gain operating region (e.g., having similar amounts of signal gain for similar amounts of X / Y probe tip position movement), the central high-gain element position range may be modified to achieve such characteristics. More specifically, in the example of Figure 8 (e.g., for a 20 mm stylus), the central high-gain element position range R4 = EP P4B -EP P4A = 0.6 degrees, which is the central high-gain probe tip position range R4 = PTP P4B -PTP P4A = 0.667 mm, and the gain is GN4 = S4 / R4 = |(SIG P4B -SIG P4A )| / (PTP P4B -PTP P4A) = 2.66 volts / 0.667 mm = 4.0 volts / mm. In the example of FIG. 10 (e.g., for a 100 mm stylus), the position range of the central high-gain element is modified to 1 / 2 of that in FIG. 8 to achieve the above-mentioned target characteristics.

[0101] More specifically, in FIG. 10, the central high-gain element position range R4=EP P4B -EP P4A = 0.3, which is the central high gain probe tip position region R4 = PTP P4B -PTP P4A = 0.667 mm, and the gain is GN4 = S4 / R4 = |(SIG P4B -SIG P4A )| / (PTP P4B -PTP P4A ) = 2.66 Volts / 0.667 mm = 4.0 Volts / mm. Thus, the desired probe tip position gain GN4 = 4.0 Volts / mm of FIG. 8 for a 20 mm stylus is maintained in FIG. 10 for a 100 mm stylus by modifying the position range R4 of the central high-gain element to be shorter (i.e., range R4 = 0.3 degrees in FIG. 10 compared to range R4 = 0.6 in FIG. 8). Similarly, if it is necessary to move from the configuration of FIG. 10 to the configuration of FIG. 8 (e.g., changing from a 100 mm stylus to a 20 mm stylus), the position range of the central high-gain element is modified to be longer (i.e., range R4 = 0.6 degrees in FIG. 8 compared to range R4 = 0.3 degrees in FIG. 10).

[0102] FIG. 11 is a diagram 1100 illustrating a process for performing a zeroing operation to adjust the zero position of the central high-gain operating region. In connection with the process and probe configurations described above, it is noted that the nominal position (e.g., as shown in FIGS. 3-6 ) is not necessarily at the zero output of the detection structure or at the geometric center of the probe. In various embodiments, certain issues due to manufacturing tolerances and electrical offsets can be compensated for by performing a zeroing operation to zero the position. In various embodiments, the central high-gain operating region and other principles disclosed herein may be applied with reference to the new nominal position resulting from such a zeroing operation.

[0103] 11, the central high-gain operating region RE4' is shown as initially corresponding to a position RL1 on the X and Y axes, and the corresponding zero position ZER' of the central high-gain operating region RE4' is shown as initially corresponding to a position ZL1 (e.g., having coordinates (0,0) on the X and Y axes). The X and Y axes relate to the X and Y probe tip positions, and the graphs of FIGS. 8 and 10 in some embodiments may represent both the X and Y probe tip position ranges, with separate graphs for each axis, and the square operating region RE4' is shown as initially corresponding to a position RL1 on the X probe tip position range R4. X X dimension and Y probe tip position range R4 corresponding to Y 8 and 10, the zero position ZER′ may be at the center of both ranges to correspond to an X, Y probe tip position of coordinate (0,0). Although not shown in FIG. 11, the first pair of lower gain operating regions combinations for each of the X and Y probe tip positions may be indicated by larger squares surrounding the central high gain operating region RE4′ square (e.g., gain adjustments may be determined according to when the XY probe tip position moves outside of the central high gain operating region RE4′ into a corresponding lower gain operating region, particularly in embodiments where the gains of the X and Y probe tip positions are not independently adjustable).

[0104] 11, the central high-gain operating region RE4' and corresponding zero position ZER' are shown as being shifted to positions RL2 and ZL2 as part of a zeroing operation to adjust for manufacturing tolerances (e.g., determined during factory calibration), and as part of a subsequent zeroing operation, the central high-gain operating region RE4' and corresponding zero position ZER' are shown as being shifted to positions RL3 and ZL3 to adjust for probe orientation (e.g., depending on the orientation of the probe when a measurement operation is being performed, gravity or other factors may affect the stylus position, etc.).

[0105] FIG. 12 is a diagram 1200 illustrating a process by which the range of the central high-gain operating region is expanded to encompass manufacturing tolerances during factory calibration. As shown in FIG. 12, a central high-gain operating region RE4′ is shown along with a corresponding zero position ZER′ (e.g., having coordinates (0,0) on the X and Y axes). To encompass manufacturing tolerances (e.g., as determined during factory calibration and indicated by a potential zero position ZERX′), the range of the central high-gain operating region is adjusted (i.e., expanded) as shown by adjusted central high-gain operating region RE4″. It will be appreciated that in various embodiments, such a process may also be performed to encompass other variations that may occur, such as due to the orientation of the scanning probe during a measurement operation (e.g., gravity or other factors may affect the stylus position).

[0106] FIG. 13 is a flow diagram illustrating an example embodiment of a routine 1300 for determining and transmitting a position sample. At block 1310, a request for a position sample is received (e.g., from a controller). At block 1320, a position sample is determined (e.g., based on signals from a detection coil). At block 1330, the position sample is analyzed to determine whether a transition operation should be performed to adjust the gain. As an example, based on the position, the gain may be adjusted to transition from a central high-gain operating region to a lower-gain operating region, or vice versa. At decision block 1340, a determination is made as to whether the analysis indicates that a transition operation should be performed. If the analysis of the position sample indicates that no transition operation needs to be performed, the routine proceeds to block 1370, as described in more detail below.

[0107] If a transition operation is to be performed, the routine proceeds to block 1350 where the transition operation is performed to adjust the gain (e.g., corresponding to a transition from a central high-gain operating region to a lower-gain operating region, or vice versa, or a transition between other operating regions corresponding to different gain levels, etc.). In various embodiments, the gain setting may be included in the position data so that appropriate compensation can be applied by the controller. In various embodiments, it may be desirable to utilize some hysteresis to prevent gain oscillations, and also when determining operating region boundaries to avoid common measurement deviations that may occur frequently. In block 1360, after the gain is adjusted, another position sample is determined (e.g., in various embodiments, the previous position sample determined before the gain was adjusted may be transmitted, discarded, etc.). In block 1370, the position sample determined after the gain was adjusted is transmitted (e.g., to the controller that requested the position sample).

[0108] With respect to blocks 1330-1360, in some embodiments, it may be desirable for the routine to return from block 1360 to block 1330 to analyze subsequently determined position samples (e.g., to verify whether more time or further adjustments are needed with respect to the current or additional transition operations, etc.). For example, in cases where saturation has occurred, several iterations may be required to fully transition to a non-saturated operating state. With respect to such operations, and the operations of block 1360 where previous position samples may be discarded, it will be understood that the sample rate in such configurations may be relatively high (e.g., relative to the speed of movement of the scanning probe and / or higher than the rate required by the controller requesting the position samples), so that in some embodiments, some of the position samples may be discarded or otherwise unused, and a subsequent position sample obtained (e.g., after the gain has been adjusted) may be transmitted and still fall within the allowed time frame of the requested position sample.

[0109] In various embodiments, it may be desirable for a process such as that shown in FIG. 13 to take into account probe tip positions along both the X and Y axes (e.g., as shown in FIGS. 11 and 12 ). For example, it will be understood that some types of transition actions may not independently change the gain relative to the X and Y probe tip positions (e.g., in some embodiments, a transition that adjusts power to a field-generating coil arrangement may affect the gain at both the X and Y probe tip positions). Thus, in some embodiments, it may be desirable for the process to take both the X and Y probe tip positions into account when a decision is made regarding a transition action to adjust the gain. For example, as shown in the embodiments of FIGS. 8 and 10 , for a range of probe tip positions further away from the center point C, the gain may be adjusted correspondingly further down to avoid potential saturation. Following such principles, in embodiments in which the gains at the X and Y probe tip positions are not independently adjusted, it may be desirable for the gain adjustment to be determined according to which probe tip position (i.e., the X or Y probe tip) is further away from the center point.

[0110] 14 is a flow diagram illustrating an exemplary embodiment of a routine 1400 for operating a scanning probe. In various embodiments, the specific operations of routines 1300 and 1400 may be similar, except that the specific operations of routine 1400 are directed to a more specific exemplary sequence (e.g., having a transition from a central high-gain operating region to a lower-gain operating region), which is described in more detail below. As shown in FIG. 14, in block 1410, a coil drive signal is provided (e.g., a field-generating coil arrangement generates a varying magnetic flux generally along an axial direction within a disruptor movement volume in response to the coil drive signal). In block 1420, a signal is input that includes respective signal components provided by the respective rotational and axial detection coils.

[0111] At block 1430, signals are output indicative of axial and rotational positions, where a change in the output signal correspondingly indicates a change in at least one of the axial or rotational positions, and three-dimensional position information (e.g., for a probe tip position, such as part of a workpiece measurement) is determined based on the output signal. At block 1440, it is determined whether a transition should be made from the central high-gain operating region to a lower-gain operating region based on the indicated position. At block 1450, in response to determining that a transition should be made, a transition operation is performed to transition from operation in the central high-gain operating region having a high gain to operation in a respective lower-gain operating region having a lower gain. In various embodiments, the transition operation may include operations for adjusting power to a field-generating coil arrangement, adjusting the gain of a front-end amplifier, changing characteristics of a detection coil, adjusting the input range of an analog-to-digital converter, etc.

[0112] As indicated above with respect to blocks 1410-1430 (e.g., pursuant to the operations of blocks 1320 and 1360 of FIG. 13 ), signals are input from the rotational and axial detection coils, and based thereon, signals are output indicative of axial and rotational positions (e.g., of the probe tip), and three-dimensional position information may be determined based on the outputs. As a specific example relating to the components of FIG. 6 (as discussed above), the digital controller / processor 681 may process and / or combine digital signal values ​​(e.g., corresponding to signals from the detection coils) according to various desired relationships (e.g., as defined by relationships such as those shown in Equations 5-7) to determine output signals APSOut and RPSOut, which indicate the axial and rotational positions (e.g., of the stylus 506 and / or its probe tip 548). In some embodiments, the digital controller / processor 681 may be configured such that the output signals APSOut and RPSOut directly indicate the three-dimensional position of the stylus 506 and / or its probe tip 548 relative to the frame of the scanning probe. In other embodiments, the digital controller / processor 681 may be configured to output signals that indirectly indicate the three-dimensional position of the stylus 506 and / or its probe tip 548 relative to the frame of the scanning probe, and a host system (e.g., CMM, host computer 120, etc.) may input such signals and perform additional processing to further combine or refine such signals to determine the three-dimensional position of the stylus 506 and / or its probe tip 548 relative to the overall coordinate system used for scanning probe and / or CMM measurement.

[0113] In either case, the determination of the signals (e.g., output signals APSOut and RPSOut) and / or subsequent calculations to determine the three-dimensional position of the stylus 506 or its probe tip 548 may include gain as a factor (e.g., the gain utilized to generate each output signal is included as a factor in the calculations to determine the corresponding position). As a simplified numerical example, with reference to Figure 8, for the central high gain operating region RE4 shown (i.e., where the corresponding signal curve portion 818 passes through the center point CEN), with gain GN4 = 4.0 volts / mm, the position of measurement point PTP (e.g., on the workpiece surface) may be calculated as follows: MP The probe tip position for PTP MP =SIG MP / GN4=SIG MP / 4.0 volts / mm. Therefore, the signal corresponding to the measurement point (i.e., the signal SIG MP ) = 1.0 volts, PTP MP = 1.0 Volts / 4.0 Volts / mm = 0.25 mm. Similarly, for the lower gain operating region RE5 shown (i.e., the corresponding signal curve portion 820 is collinear with signal curve portion 816 and has a line passing through center point CEN), at gain GN5 = 1.5 Volts / mm, the measurement point PTP MP The probe tip position for MP =SIG MP / GN5=SIG MP / 1.5 volts / mm. Therefore, the signal corresponding to the measurement point (i.e., the signal SIG MP ) = 1.0 volts, PTP MP = 1.0 volts / 1.5 volts / mm = 0.67 mm. Similar calculations may be performed with respect to signal curve portions that are not collinear with a line passing through the center point CEN, and an offset value may be included in the calculation according to known methods, or in some embodiments, the gain and operating region may be configured so that all signal curve portions are collinear with a line passing through the center point CEN, and calculations such as those described above may be used.

[0114] In some embodiments, the length of the stylus (which may be a factor in the position calculation of the probe tip, e.g., as shown by Equations 2 and 3) may be manually indicated / input by a user or may be automatically detected (e.g., according to a sensor configuration for detecting the stylus length, such as an RFID tag, optical indicator, etc. on the stylus that is detected / read by a corresponding sensor / scanner, etc., of the system). As noted above, gain (e.g., adjusted by a transition operation according to the operating region, and the stylus length may determine the extent and / or characteristics of the operating region utilized, e.g., as shown by the difference between Figures 8 and 10) may be a factor in the position calculation / determination.

[0115] As noted above, in some embodiments, the gain may be adjusted independently for each of the X and Y probe tip positions (e.g., may correspond to output signal RPSOut), in which case the respective gains may be adjusted during operation and utilized as a factor as part of the calculation for each of the X and Y probe tip positions (e.g., the gains may be adjusted by a transition operation according to an operating region such as that of FIG. 8 or FIG. 10 for each of the X and Y probe tip positions). Alternatively, in some embodiments, the gains may not be adjusted independently for the X and Y probe tip positions (e.g., may correspond to output signal RPSOut), in which case a single gain may be adjusted during operation and utilized as a factor as part of the calculation for both the X and Y probe tip positions (e.g., in some embodiments, a single gain may be adjusted by a transition operation according to an operating region such as that of FIG. 8 or FIG. 10 when either the X or Y probe tip position is away from the center point).

[0116] As a specific example relating to FIG. 8, in an embodiment where a single gain is utilized, the X probe tip position PTP MPX is the operating region RE4 (for example, for each X probe tip position graph). X Range of R4 X Y probe tip position PTPMPY is the operating region RE5 (for example, for each Y-probe tip position graph). Y Range of R5 Y If it is within, Y probe tip position PTP MPY is far from the center point CEN, in some embodiments a single gain GN5 = 1.5 volts / mm may be utilized for both the X and Y probe tip positions, and the measurement point PTP MP Each of the X and Y probe tip positions of the PTP MP =SIG MP / GN5=SIG MP For example, the position of the tip of the Y probe may be determined according to the output signal (i.e., the signal SIG MPY ) = 1.0 volts, PTP MPY = 1.0 volts / 1.5 volts / mm = 0.67 mm. Similarly, for the X probe tip position, the output signal corresponding to the measurement point (i.e., the signal SIG MPX )=0.375 volts, PTP MPX = 0.375 volts / 1.5 volts / mm = 0.25 mm. MP may be specified to be at corresponding (X,Y) measurement coordinates of (0.25 mm, 0.67 mm). As mentioned above, the central high gain operating region RE4' of the square in FIG. 11 at position ZL1 is within the X probe tip position range R4 X X and Y dimensions corresponding to the probe tip position range R4 Y (e.g., each extending from 0.33 mm to −0.33 mm according to the exemplary values ​​of FIG. 8), the probe tip position PTP MP For , the corresponding measurement coordinate (+0.25 mm, 0.67 mm) is outside the central high gain operating region RE4' of the square (i.e., PTP MPY=+0.67 mm, and the single corresponding gain utilized is GN5=1.5 Volts / mm in the first lower gain operating region RE5, rather than the gain GN4=4.0 Volts / mm that would have been utilized had the measurement coordinates fallen within the central high gain operating region RE4' of the square.) As noted above, in alternative embodiments in which the gains for each of the X and Y probe tip positions may be adjusted independently, in such a scenario, a gain GN5=1.5 Volts / mm may be utilized for the Y probe tip position (i.e., with values ​​as shown above), and a gain GN4=4.0 Volts / mm may be utilized for the X probe tip position (i.e., PTP MPX = 0.25 mm and the corresponding signal is SIG MPX =(PTP MPX )(GN4 X ) = (0.25 mm)(4.0 volts / mm) = 1.0 volts. This higher signal SIG is generated by gain GN4 = 4.0 volts / mm. MPX = 1.0 volts will generally result in a lower signal SIG than would be produced by a gain GN5 = 1.5 volts / mm. MPX =0.375 volts (e.g., due to a corresponding higher signal-to-noise ratio of the signal, etc.), and therefore, it is noted that the above numerical examples illustrate certain desirable properties of the techniques disclosed herein.

[0117] More specifically, in accordance with the principles disclosed herein, the extent of the central high-gain operating region and the lower-gain operating region may be determined according to a typical probe tip deflection during a measurement operation. For example, in some embodiments, a typical probe tip deflection may be less than a few hundred microns (e.g., due to scanning a workpiece having relatively small defects, generally known dimensions, and where the scanning motion is well controlled to track along the workpiece's surface and / or other features). In such embodiments, the extent of the central high-gain operating region may be determined to include a majority of such typical probe tip deflections (e.g., extending from -0.33 mm to +0.33 mm, or extending from -0.5 mm to +0.5 mm, etc.), and a relatively high gain (e.g., 4.0 volts / mm) may be utilized (e.g., resulting in a higher output signal level for a typical probe tip deflection / measurement with a corresponding better signal-to-noise ratio). Additionally, the lower gain operating region of one or more pairs of such configurations allows for a wider overall range to be implemented (e.g., extending from −1.67 mm to +1.67 mm, or extending from −2.0 mm to +2.0 mm, and / or corresponding to the full mechanical range, etc.), which may be utilized for probe tip deflections outside of the typical range (e.g., due to possible over-travel of the scanning probe during a measurement operation, due to measuring large defects, as part of collision detection indicated by the probe tip being deflected to the end of its mechanical range, etc.).

[0118] It will be appreciated that the principles described above with respect to Figures 7 to 14 may be utilized in stylus position detectors and associated electronics, for example stylus position detectors 411, 511, 511' described above with respect to Figures 3 to 6. Additionally, such principles may also be utilized in other configurations of stylus position detectors. As some specific examples, such principles may be utilized in the configurations disclosed in previously incorporated U.S. Patent Application Publication No. 2020 / 0141717, as well as in co-pending, commonly owned U.S. patent application Ser. No. 17 / 135,665, entitled "Inductive Position Detection Configuration for Indicating a Measurement Device Stylus Position," filed December 28, 2020, and co-pending, commonly owned U.S. patent application Ser. No. 17 / 135,672, entitled "Inductive Position Detection Configuration for Indicating a Measurement Device Stylus Position and Including Coil Misalignment Compensation," filed December 28, 2020, each of which is incorporated by reference in its entirety herein. While these incorporated references show particular configurations having variations in terms of location, size, and / or shape of the detection coils, field-generating coils, disruptor elements, etc. (e.g., with a single printed circuit board containing all coils in the coil board configuration, and / or cylindrical disruptor elements configured to move and fit within holes in the coil board configuration, etc.), it will be understood that the coils and / or associated operations are similar to the stylus position detection units 411, 511, 511' described above with respect to Figures 3-6 and the configurations may be similarly utilized / implemented with the operations, regions, ranges, calculations, etc. disclosed herein.

[0119] While preferred embodiments of the present disclosure have been illustrated and described, numerous variations in the illustrated and described arrangement of features and sequences of operations will be apparent to those skilled in the art based on this disclosure. Various alternative forms may be used to implement the principles disclosed herein. Additionally, the various embodiments described above can be combined to provide further embodiments. All U.S. patents and U.S. patent applications referenced herein are incorporated herein by reference in their entirety. Aspects of the embodiments can be modified, if necessary, to employ concepts from the various patents and applications to provide further embodiments.

[0120] These and other changes can be made to the embodiments in light of the above detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments, along with the full range of equivalents to which such claims are entitled.

Claims

1. 1. A scanning probe for a coordinate measuring machine, comprising: a stylus coupling portion configured to be securely coupled to a stylus having a probe tip; a stylus movement mechanism configured to allow axial movement of the stylus coupling portion along an axial direction and rotational movement of the stylus coupling portion about a center of rotation; a stylus suspension coupled to a frame of the scanning probe, the stylus suspension including: a field generating coil arrangement including at least one field generating coil; an upper axial detection coil arrangement including at least one upper axial detection coil; a lower axial detection coil arrangement including at least one lower axial detection coil; N upper rotation detection coils and N lower rotation detection coils (N is an integer greater than 3); a stylus position detector arranged along a central axis parallel to the axial direction and nominally aligned with the center of rotation; a disruptor arrangement including a conductive disruptor element providing a disruptor region, the disruptor element located along the central axis within a disruptor movement volume, the disruptor element coupled to the stylus suspension by a coupling arrangement, the disruptor element moving within the disruptor movement volume to an undeflected position in response to deflection of the stylus suspension, the disruptor element moving along the axial direction through an operational range of movement + / -Rz in response to the axial movement, and along orthogonal X and Y directions orthogonal to the axial direction through respective operational ranges of movement + / -Rx and + / -Ry in response to the rotational movement, the field generating coil arrangement generating a varying magnetic flux in the disruptor movement volume generally along the axial direction in response to a coil drive signal; and a signal processing and control circuit operatively connected to the coils of the stylus position detection portion to provide the coil drive signals, the signal processing and control circuit being configured to input signals including respective signal components provided by the upper and lower rotational detection coils and the upper and lower axial detection coils, and to output signals indicative of axial and rotational positions of the probe tip, wherein changes in the output signals correspondingly indicate changes in at least one of the axial or rotational positions of the probe tip, the signal processing and control circuit being configured to operate over a plurality of operating regions, the plurality of operating regions comprising: a central high-gain operating region corresponding to a central high-gain probe tip position range; a first pair of lower gain operating regions corresponding to respective lower gain probe tip position ranges, the central high-gain operating region being between the first pair of lower gain operating regions, the gain of each operating region corresponding to the ratio of the magnitude of change in output signal to the change in probe tip position of the respective operating region, the first pair of lower gain operating regions having respective gains lower than the gains of the central high-gain operating region; the signal processing and control circuitry is configured to perform a transition operation in response to determining that the probe tip has moved from a position within the central high-gain probe tip position range of the central high-gain operating region to a position within a lower gain probe tip position range of a respective operating region of the first pair of lower gain operating regions, the transition operation causing the signal processing and control circuitry to transition from operation in the central high-gain operating region having a high gain to operation in the respective operating region having a lower gain.

2. 2. The scanning probe of claim 1, The plurality of operating regions are each a first region corresponding to a respective lower gain probe tip position range. further comprising two pairs of lower gain operating regions, the operating region of the first pair of lower gain operating regions being between the lower gain operating regions of the second pair, the lower gain operating regions of the second pair having respective gains lower than the lower gain operating regions of the first pair; the signal processing and control circuitry is further configured to perform a transition operation in response to determining that the probe tip has moved to a position within a lower gain probe tip position range of a respective operating region of the second pair of lower gain operating regions, the transition operation causing the signal processing and control circuitry to transition to operation in the respective operating region of the second pair of lower gain operating regions having the lower gain.

3. 3. The scanning probe of claim 2, the plurality of operating regions further includes a pair of saturated operating regions corresponding to respective saturated probe tip position ranges, the second pair of lower gain operating regions being between the pair of saturated operating regions, the pair of saturated operating regions corresponding to saturated conditions where there is no nominal change in output signal due to changes in position of the probe tip and nominal corresponding nominal change in gain.

4. 4. The scanning probe of claim 3, The signal processing and control circuitry includes one or more amplifiers configured to amplify signals from a coil of the stylus position detection unit, and the saturation state corresponds to saturation of at least one of the one or more amplifiers.

5. 2. The scanning probe of claim 1, the central high-gain operating region corresponding to the central high-gain probe tip position range also corresponds to a central high-gain element position range that corresponds to an angular position range of the disruptor element and that is configured to be utilized in combination with a stylus having a first stylus length; For a stylus of the second stylus length, the central high gain element position range is: shorter so as to be adapted to be utilized with a second stylus length that is longer than the first stylus length; or longer or adapted to be utilized with a second stylus length that is shorter than the first stylus length; 10. A scanning probe configured to be modified to be at least one of:

6. 2. The scanning probe of claim 1, The scanning probe of claim 1, wherein the signal processing and control circuitry is further configured to perform a zeroing operation to adjust a zero position of the central high gain region of operation.

7. 2. The scanning probe of claim 1, The signal processing and control circuitry includes: To accommodate manufacturing tolerances during factory calibration, or To accommodate variations that may occur due to the orientation of the scanning probe during measurement operations. a scanning probe further configured to have at least a positional range of said central high-gain operating region expanded to perform at least one of:

8. 2. The scanning probe of claim 1, The transition operation reduces the power of the field generating coil arrangement to reduce the ratio of the magnitude of the change in output signal to the change in probe tip position, corresponding to the lower gain.

4. A scanning probe comprising:

9. 9. The scanning probe of claim 8, 10. A scanning probe as claimed in claim 9, wherein reducing power in the field generating coil arrangement comprises reducing the coil drive signal.

10. 2. The scanning probe of claim 1, a signal processing and control circuit configured to amplify a signal from a coil of the stylus position detection unit, and wherein the transition operation includes reducing the gain of the one or more variable gain amplifiers to reduce the ratio of the magnitude of change in output signal to change in probe tip position, corresponding to the lower gain.

11. 2. The scanning probe of claim 1, 10. The scanning probe of claim 9, wherein the transition operation includes modifying a characteristic of one or more of the rotational detection coils to reduce the ratio of a magnitude of change in output signal to a change in probe tip position, corresponding to the lower gain.

12. 2. The scanning probe of claim 1, a signal processing and control circuit including one or more analog-to-digital converters configured to convert analog signals from the coils of the stylus position detection unit into digital signals, and the transition operation includes changing the input range of the one or more analog-to-digital converters to reduce the ratio of the magnitude of change in output signal to change in probe tip position to correspond to the lower gain.

13. 2. The scanning probe of claim 1, 10. A scanning probe comprising: a scanning probe having a stylus position detector configured to detect a position of a scanning tip within a range of positions of the scanning tip; a scanning probe having a stylus position detector configured to detect a position of the scanning tip;

14. 14. The scanning probe of claim 13, and after the determination is made that the probe tip has moved within the respective lower gain probe tip position range based on the analysis of the corresponding position samples, and after the transition operation is performed to correspondingly lower the gain, a new position sample is acquired and utilized to indicate the probe tip position in place of the position sample acquired before the transition operation was performed to lower the gain.

15. 1. A method comprising: determining three-dimensional position information based on inductive detection signals generated by the scanning probe as the scanning probe moves along the surface of the workpiece, the scanning probe comprising: a stylus suspension coupled to a frame of the scanning probe, a stylus coupling portion configured to be securely coupled to a stylus having a probe tip; a stylus movement mechanism configured to allow axial movement of the stylus coupling portion along an axial direction and rotational movement of the stylus coupling portion about a center of rotation; the stylus suspension comprising: a stylus position detector arranged along a central axis parallel to the axial direction and nominally aligned with the center of rotation, a field generating coil arrangement including at least one field generating coil; an upper axial detection coil arrangement including at least one upper axial detection coil; a lower axial detection coil arrangement including at least one lower axial detection coil; a stylus position detection unit including N upper rotation detection coils and N lower rotation detection coils (N is an integer greater than 3); a disruptor arrangement including a conductive disruptor element providing a disruptor region, the disruptor element located along the central axis within a disruptor movement volume, the disruptor element coupled to the stylus suspension by a coupling arrangement, the disruptor element moving within the disruptor movement volume to an undeflected position in response to deflection of the stylus suspension, the disruptor element moving along the axial direction through an operational range of movement of + / -Rz in response to the axial movement, and along orthogonal X and Y directions orthogonal to the axial direction through respective operational ranges of movement of + / -Rx and + / -Ry in response to the rotational movement, the field generating coil arrangement generating a varying magnetic flux in the disruptor movement volume generally along the axial direction in response to a coil drive signal; determining the three-dimensional position information based on induced detection signals generated by the scanning probe, providing the coil drive signal; inputting a signal including respective signal components provided by the upper and lower rotational detection coils and the upper and lower axial detection coils; a change in the output signal correspondingly indicates a change in at least one of the axial or rotational position of the probe tip, so that the three-dimensional position information is determined based on the output signal; and outputting a signal indicative of the axial and rotational position of the probe tip. determining whether to transition from a central high gain region of operation to a lower gain region of operation based on the indicated position of the probe tip; the central high-gain operating region corresponds to a central high-gain probe tip position range; and determining that the lower gain operating region is one of a first pair of lower gain operating regions corresponding to a respective lower gain probe tip position range, the central high-gain operating region being between the first pair of lower gain operating regions, the gain of each operating region corresponding to a ratio of a magnitude of change in output signal to a change in probe tip position in the respective operating region, the first pair of lower gain operating regions having a respective gain lower than the central high-gain operating region, such that a transition from the central high-gain operating region to a respective lower-gain operating region should occur when it is determined that the probe tip has moved from a position within the central high-gain probe tip position range to a position within a respective lower-gain probe tip position range; performing a transition operation in response to determining that a transition from the central high-gain region of operation to a lower gain region of operation should occur, the transition operation resulting in a transition from operation in the central high-gain region of operation having a high gain to operation in the respective lower-gain region of operation having a lower gain; A method comprising:

Images