Apparatus and method for processing rotation-dependent measurement values
By dividing the rotation of the axis into sectors and generating angle-based result values, the computationally intensive problem of evaluating the influence of the rotation axis in the prior art is solved, and a simple and efficient evaluation method is realized.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- DR JOHANNES HEIDENHAIN GMBH
- Filing Date
- 2021-09-07
- Publication Date
- 2026-06-23
Smart Images
Figure CN114235358B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to an apparatus for processing rotation-dependent measurements and a corresponding method. Background Technology
[0002] In automation technology, multiple motion processes are based on rotating shafts, directly or indirectly driven by electric motors. Even without external forces, a rotating shaft can influence machine parts, for example, by causing mechanical vibrations through imbalance. This effect is amplified many times over if external forces are also applied to the shaft, especially when the resonant frequencies of the machine parts are related.
[0003] A particularly sensitive technical area here is the high-precision machining of workpieces in machine tools. Here, the motor spindle is a key component because it comprises shafts that operate at different speeds and are loaded with high lateral and dynamically changing forces according to the machining steps.
[0004] Taking milling as an example, forces arise during operation through cutting, influenced by the feed rate and also by the number and state of cuts made by the milling tool. These forces cause dynamic bending of the shaft, which can have a variety of negative effects on the machine tool.
[0005] In order to analyze this effect, a variety of sensors are used, such as accelerometers for detecting vibrations or solid-state acoustic sensors or strain gauges for demonstrating bending.
[0006] EP 2 924 526 A1 describes a method for monitoring the operating parameters of a machine tool. For this purpose, measurements are performed using sensors at constant time intervals, and the measured values are displayed graphically. A disadvantage of this method is that, especially at low speeds, a very large number of measurements are taken in each revolution of the axis, making the evaluation very storage- and computationally intensive. Summary of the Invention
[0007] The objective of this invention is to describe an apparatus that provides result data that allows for a simple evaluation of the effects of a rotating shaft on machine parts.
[0008] This task is solved using a device that processes measurements that depend on rotation.
[0009] A device for processing rotation-dependent measurements is now proposed, comprising a data converter, a process controller, and an output interface, wherein...
[0010] • Within a constant time interval of the measurement interval, a series of measurement values can be transmitted to the data converter. These measurement values depend on the rotation of the axis, and at least one of these measurement values is an angular value indicating the angular position of the axis.
[0011] • The data converter is designed to divide the axis rotation into n sectors. Using one of the angle values as a reference angle value, the arrived measurement values are assigned to the sectors, and in each rotation of the axis, exactly one result value is obtained for each series of measurements in each sector.
[0012] • The result value can be output to the output interface.
[0013] Furthermore, the objective of this invention is to describe a method for obtaining result data that allows for a simple evaluation of the effects of a rotating shaft on machine components.
[0014] This task is solved by a method of running a device for processing measurements that depend on rotation.
[0015] A method is now proposed for operating a device for processing rotation-dependent measurements, the device comprising a data converter, a process controller, and an output interface, wherein...
[0016] • Within a constant time interval of the measurement interval, a series of measurement values can be transmitted to the data converter. These measurement values depend on the rotation of the axis, and at least one of these measurement values is an angular value indicating the angular position of the axis.
[0017] • In the data converter, the axis rotation is divided into n sectors, and with one of the angle values used as a reference angle value, the arrived measurement value is assigned to the sector. In each rotation of the axis, exactly one result value is obtained for each series of measurements in each sector.
[0018] • Output the result value to the output interface. Attached Figure Description
[0019] Further advantages of the device or method according to the invention are obtained from other preferred embodiments or described examples. Wherein:
[0020] Figure 1 A simplified illustration of a machine tool with a motor spindle is shown;
[0021] Figure 2 An embodiment of the device according to the present invention is shown;
[0022] Figure 3 It shows Figure 2 Signal diagram of the implementation method;
[0023] Figure 4 A value table is shown to illustrate the method according to the present invention;
[0024] Figure 5A Alternative embodiments of the measuring device are shown;
[0025] Figure 5B Another embodiment of the measuring device is shown;
[0026] Figure 5C Another embodiment of the measuring device is shown;
[0027] Figure 6A Alternative embodiments of the measuring device are shown;
[0028] Figure 6B Another embodiment of the measuring device is shown;
[0029] Figure 7 Further embodiments of the device according to the invention are shown; and
[0030] Figure 8 Another embodiment of the device according to the invention is shown. Detailed Implementation
[0031] In the following description of advantageous embodiments of the invention, reference numerals for the parts and functional components described in the drawings are included in the following drawings.
[0032] Figure 1 A machine tool with a motor spindle 10 is shown in a simplified manner. The central component is a spindle motor 1 with a shaft 2. A tool 4 (e.g., a milling tool) is arranged on the end of the shaft 2. A tool holder (not shown), such as a chuck or a hollow shank taper, is provided to secure the tool 4 to the shaft 2. An angle measuring device 5 (rotary encoder, Drehgeber) is also mechanically coupled to the shaft 2. The coupling is achieved via a mechanical clutch (not shown), which connects the rotatable shaft of the angle measuring device 5 to the shaft 2. In this way, the angular position and / or the number of revolutions passed by the shaft 2 can be measured using the angle measuring device 5. The shaft 2 is supported in the housing of the spindle motor 1 by rolling bearings.
[0033] During the machining of workpiece 6, shaft 2 rotates at a variable speed N, and tool 4 contacts workpiece 6 via the relative movement of motor spindle 10 relative to workpiece 6. Thus, for example in milling, a desired contour is milled from workpiece 6. Relative movement can occur along linear drive axes X, Y, Z, and additionally, so-called pivot axes A, B can be provided, making movement along five motion axes X, Y, Z, A, B possible in the example shown. The movement of each axis is controlled by a servo drive (not shown), which in turn drives the corresponding mechanical components. Additional position measuring devices 20X, 20Y, 20Z, 20A, and 20B are provided in the machine tool to determine the positions of the corresponding motion axes X, Y, Z, A, and B.
[0034] Furthermore, a multi-position measuring device 8 can be installed in the motor spindle 10, whose structure and function are combined Figure 7 Let me elaborate.
[0035] The rotation of shaft 2 can have various effects on the operation of the machine tool. Even when tool 4 is not in contact with workpiece 6, vibrations dependent on the rotational speed may occur due to shaft imbalance, bearing clearance of rolling bearings, eccentricity errors, etc. The force exerted on tool 4 when workpiece 6 is delivered has a more serious impact on the machine tool (usually in the same form as mechanical vibration).
[0036] In addition, a sensor 30 is installed in the motor spindle 10, which can be used to measure other machine conditions. This sensor can be an accelerometer, vibration sensor, solid-state acoustic sensor, strain gauge, or a measuring resistor for measuring current, etc. The measured values from the angle measuring device 5, position measuring devices 20X, 20Y, 20Z, 20A, 20B, the multiple position measuring device 8, and the sensor 30 can be transmitted to the control device 40 via appropriate cables. The control device 40 has an interface for connecting cables and is used to detect and process the measured values.
[0037] Figure 2 based on Figure 1 The machine architecture shown illustrates an embodiment of the device according to the present invention.
[0038] The core function of the device according to the invention is to process a series of measurements that depend on rotation. These are measurements that are affected by the rotation of shaft 2. In addition to obvious influences, such as changes in the angular position of shaft 2 itself, these are particularly affected by forces generated by the rotating shaft 2 itself or acting on shaft 2 during machine operation. Different measuring devices are provided for measuring and providing these measurements. A first measuring device 70 is suitable for measuring the angular position of shaft 2. The first measuring device includes an angle measuring device 5, a data transmission channel 50, and a data interface 43. Furthermore, two additional measuring devices 80 and 90 are provided, namely a second measuring device 80 (which represents...). Figure 1 The position measuring devices 20X, 20Y, 20Z, 20A, and 20B shown include a position measuring device 20X for measuring motion along the direction of the motion axis X and a third measuring device 90, which has a sensor 30 (numerically named in this example) as a measuring device. The second measuring device 80 and the third measuring device 90 also have data transmission channels 51 and 52 and data interfaces 44 and 45, respectively.
[0039] The selection of position measuring device 20X is arbitrary and unrestricted. Obviously, each position measuring device 20X, 20Y, 20Z, 20A, 20B, whose influence on the rotating shaft 2 should be examined, can be used as a measuring unit in other measuring devices.
[0040] The measuring apparatus within the scope of this invention includes all necessary components to perform measurements triggered by external signals and to provide or output the learned measurement values digitally. The structure includes at least one measuring device, a transmission channel, and an interface. At least one measuring parameter to be checked can be detected using the at least one measuring device, and can be transmitted via the transmission channel, depending on the implementation of the measuring device, to the interface in the form of digital measurement values and / or measurement signals to be evaluated.
[0041] In the first measuring device 70, the angular position of the shaft 2 can be measured using the angle measuring device 5. The angle measuring device is implemented as a so-called absolute angle measuring device. The initialization of the angle measurement is performed by sending a request command RQW from the data interface 43 to the angle measuring device 5 via the data transmission channel 50. The generated angle value MW is transmitted from the angle measuring device 5 to the data interface 43 in the opposite direction via the data transmission channel 50.
[0042] Similarly, in the second measuring device 80, the position value MX can be measured using the position measuring device 20X and transmitted to the data interface, and then transmitted to the data interface 44 via the data transmission channel 51. The measurement is initialized by the request command RQX.
[0043] The sensor 30 in the third measuring device 90 is implemented as a digital sensor, so it also performs a measurement when the request command RQS arrives and transmits it to the data interface 45 via the data transmission channel 52.
[0044] The control device 40 includes a process controller 46, a data converter 60, and an output interface 62. Furthermore, the data interfaces 43-45 of the measuring devices 70, 80, and 90 are part of the control device 4.
[0045] In the example shown, all data interfaces are designed for point-to-point data transmission, meaning that data interfaces 43-45 communicate with connected digital measuring devices (angle measuring device 5, position measuring device 20X, and sensor 30) through corresponding data transmission channels 50-52.
[0046] The process controller 46 generates measurement pulses MP at constant time intervals and transmits them to the measuring devices 70, 80, and 90 via signal line 47. Data interfaces 43-45 then request measurement values by sending request commands RQW, RQX, and RQS to the angle measuring device 5, position measuring device 20X, and sensor 30 via data interfaces 43, 44, and 45. The measurement values MW, MX, and MS, as a result of the request commands RQW, RQX, and RQS, arriving at the corresponding data interfaces 43, 44, and 45, are transmitted to the data converter 60. This operation forms a series of measurement values, wherein the various measurement values MW, MX, and MS of the measuring devices 70, 80, and 90 are measured as simultaneously as possible. Therefore, the measurement values MW, MX, and MS are time-based.
[0047] It should be noted here that identical data interfaces are not required. Instead, any data interface that supports request commands is suitable, where request commands can be represented by any signal or any sequence of signals. The medium forming data transmission channels 50, 51, and 52 is also arbitrary. Therefore, it can be a wire, an optical fiber, or a wireless connection. In the case of a wire, signal transmission can be performed differently, for example, according to the known RS-485 standard. Therefore, a pair of wires can be set up for bidirectional data channels, and another pair can be set up for a clock signal channel (Taktsignalkanal) if necessary.
[0048] In data converter 60, the time-based measurements generated in measuring devices 70, 80, and 90 are now converted into angle-based virtual result values. For this purpose, one rotation of axis 2 is divided into n sectors, and a virtual angle-based measurement is determined for each of the n sectors. The measurement value MW from measuring device 70 is used as a reference for the current angular position of axis 2, and the current allocation of the sectors is based on this reference.
[0049] The result value is output to output interface 62, from which it can be sent to subsequent electronic devices for further evaluation. Advantageously, the result value can be stored in output interface 62, allowing it to be output at a later time.
[0050] In summary, the control device 40 comprises a measurement module having an interface for connecting to a measuring device via a suitable transmission channel, a processing device for processing the measured values into result values according to the present invention, and an output interface for outputting the result values. The control device 40 may be a standalone device, but it may also be implemented as a measurement module within a machine control system.
[0051] Figure 3 It shows the use of Figure 2 The signal diagram of the embodiment shown.
[0052] The top row of the signal diagram shows the measurement pulse MP, which is output from the process controller 46 to the measuring devices 70, 80, and 90 via signal line 47 during a constant measurement interval T. The arrival of the measurement pulse MP can be identified by monitoring signal characteristics, such as the arrival of a defined signal edge or a change in signal level.
[0053] The following lines symbolically illustrate the communication within measuring devices 70, 80, and 90 via data transmission channels 50-52 following the arrival of the measuring pulse MP. Signals along the directions of the angle measuring device 5, the position measuring device 20x, and the sensor 30 are shown in the area above the neutral line, while signals along the directions of the data interface 43-45 are shown below the neutral line. The signal polarity and the number of lines used for transmission cannot be extracted from the diagram.
[0054] If the measurement pulse MP arrives, the data interface 43-45 directly sends request commands RQW, RQX, and RQS to the corresponding measuring devices, namely the angle measuring device 5, the position measuring device 20X, and the sensor 30, through the data transmission channels 50-52. The measuring devices then simultaneously perform the measurement and generate measured values, namely the angle value MW, the position value MX, and the sensor value MS, which are then transmitted to the data interface 43-45.
[0055] The request commands RQW, RQX, and RQS are interface-specific. The following data interfaces are known to use request commands RQW, RQX, and RQS in... Figure 3 The data word (instruction word) shown is the defined data word. In other data interfaces, the arrival of signal edges has been interpreted as request commands RQW, RQX, and RQS.
[0056] The measured values MW, MX, and MS are output by the measuring devices 70, 80, and 90 to the data converter 60 for further processing.
[0057] In the data converter 60, the result value is obtained based on the arrived measurement values MW, MX, and MS. Then, according to... Figure 4 Describe the appropriate and preferred methods for this purpose.
[0058] Figure 4 The first table is shown, containing continuously measured values MW, MX, and MS. The angle value MW is described in degrees (º), and the position value MX is described in millimeters (mm). The sensor value MS is assumed to be unitless, for example, as an integer with a 16-bit value range. Furthermore, Figure 4 A second table is shown, containing the resulting values EW, EX, ES obtained by the data converter from the values in the first table.
[0059] For the purposes of the subsequent implementation, it is assumed that the rotation of axis 2 is divided into 120 identical sectors (SECs). Each sector (SEC) therefore includes an angle range of 3°. The angle value MW, used as a reference angle value, determines which sector (SEC) is currently assigned the measured values MW, MX, and MS. Thus, the angle values MW with table values of 0.9° and 2.1° are assigned to sector 1, for example. Consequently, the position values MX with table values of 113.43 mm and 114.98 mm and the sensor values MS with table values of 5854 and 5850 are also assigned to sector 1, since they were measured at the same time points as the corresponding angle values MW.
[0060] According to the present invention, the data converter 60 now obtains a result value from at least one of the measurement series of the measuring devices 70, 80, 90 in each sector SEC. Similar to the measured values (angle value MW, position value MX, sensor value MS), the result values have reference numerals EW, EX, and ES, respectively supplemented by sector encoding.
[0061] Subsequent methods for obtaining the result values proved to be particularly advantageous.
[0062] The first method is to select the first measurement after the sector change (or the last measurement before the sector change) as the result values EW, EX, ES. This method is particularly simple because no calculation is required. Advantageously, the measurement interval T is chosen such that a large number of measurements MW, MX, MS are taken for each sector SEC during continuous operation. In the simple example shown, for instance, when selecting the first measurement after the sector change, in the positive rotation direction, for sector SEC=1, the angle result value EW1 = 0.9º, the position result value EX1 = 113.43mm, and the sensor result value ES1 = 5854 are obtained.
[0063] In the second method, the average values of all measurements MW, MX, and MS within sector SEC are used to form the result values EW, EX, and ES, respectively. This method can be used if at least two measurements MW, MX, and MS are measured for each sector SEC. A particular advantage of this method is that it enables low-pass filtering of the measurement values MW, MX, and MS. Here, for sector SEC = 1, the angle result value EW1 = 1.5º, the position result value EX1 = 114.205 mm, and the sensor result value ES1 = 5852 are obtained.
[0064] The third method calculates virtual measurement values as result values EW, EX, ES based on at least two measurements MW, MX, MS within the current sector SEC, using the intermediate angular position. Suitable calculation methods can be used here, particularly interpolation methods such as linear interpolation, polynomial interpolation, and spline interpolation. This method reduces the jumps between result values EW, EX, ES caused by the asynchronous measurement of MW, MX, MS, and the rotational motion (jitter) of axis 2, and these jumps are therefore very accurate. In linear interpolation, in the example of sector SEC = 1, the angle result value EW1 = 1.5º, the position result value EX1 = 114.205mm, and the sensor result value ES1 = 5852 are obtained, calculated for the sector center point in the 1.5º case.
[0065] In all methods, the measured values MW, MX, and MS are assigned to sector SEC based on the angle value MW, which is measured by the measuring device 70 as a reference angle value.
[0066] The obtained and provided result values EW, EX, ES can be output via output interface 62 to a subsequent electronic device (not shown) for further evaluation. Alternatively, output interface 62 can be implemented as a graphical interface, and a display device, such as a monitor, can be connected to this graphical interface, displaying the changes in the result values EW, EX, ES graphically. In this case, the changes in the result values EW, EX, ES can be visually evaluated or judged by an observer.
[0067] Figures 5A to 5C Another advantageous embodiment of the measuring device is shown. Here, in Figure 5A and 5B The measuring device shown can, for example, replace Figure 2 Measuring device 80, Figure 5C It can be used to replace measuring device 90.
[0068] exist Figure 5A The measuring device 180 shown includes an incremental encoder 120, whose analog position signals sin, cos, and ref are transmitted to the processing interface 144 via a signal transmission channel 151. The incremental encoder 120 can be implemented as an angle measuring device (rotary encoder) or a length measuring device.
[0069] The position signals sin, cos, and ref of the incremental encoder 120 are generated by an indexing structure based on a scanning rule, as is known in the prior art. The position signals sin and cos are primarily sinusoidal at a constant rotational or travel speed and have a 90° phase shift between each other. The number of indexing cycles of the indexing structure corresponds to the number of signal cycles of the position signals sin and cos. Therefore, the position can be determined by evaluating the position signals sin and cos in conjunction with the position signal ref, which determines a reference position.
[0070] Processing interface 144 obtains the current position value MX relative to a reference position by evaluating (counting) the signal period of the position signal sin and cos and, if necessary, evaluating a portion of the signal period (interpolation).
[0071] Now, if the measurement pulse MP arrives, the other measuring device 180 outputs the current position value MX through the processing interface 144.
[0072] exist Figure 5B The measuring device 280 shown also includes an incremental encoder 220. However, compared to... Figure 5A In contrast, the incremental encoder outputs digital position signals A, B, and R to the processing interface 244 via signal transmission channel 251.
[0073] Position signals A and B are rectangular and are shifted 90° from each other. Position signal R is used to determine the reference position and is also rectangular in this case.
[0074] The processing interface 244 obtains the current position value MX by counting the signal period or signal edge of position signals A and B relative to the reference position.
[0075] Here, the additional measuring device 280 also outputs the current position value MX after the measuring pulse MP arrives via the processing interface 244.
[0076] Figure 5C The additional measuring device 190 includes an analog sensor 130, whose analog sensor signal S is transmitted to the processing interface 145 via the signal transmission channel 152.
[0077] The analog sensor 130 may include any component or circuit that converts the parameter to be measured into an electrical signal. The analog sensor may include a variable resistor, such as a strain gauge (DMS), or a constant measuring resistor, such as one used to measure the motor current of the spindle motor 1.
[0078] The processing interface 145 is appropriately designed to generate or output the sensor value MS from the sensor signal S after the arrival of the measurement pulse MP. For this purpose, an A / D converter and computing circuitry can be configured.
[0079] Figure 6A and 6B Alternative embodiments of the measuring device are shown, which can replace... Figure 2 The measuring device 70.
[0080] exist Figure 6A The measuring device 170 shown corresponds to the measurement device 170 in Figure 5A The measuring device 180 is shown in the figure. Since this measuring device is used to measure the angular position of shaft 2, the measuring equipment in this case is limited to the incremental rotary encoder 105, whose analog position signals sin, cos, and ref are transmitted to the processing interface 143 via signal transmission channel 150. Similar to measuring device 70, measuring device 170 outputs the angle value MW as a result of the arrival of the measuring pulse MP.
[0081] and Figure 6A Compared with Figure 5B Similarly, the measuring device 270 includes an incremental rotary encoder 205, which outputs digital position signals A, B, and R to the processing interface 243 via a signal transmission channel 250. Here, the arrival of the measuring pulse MP also results in the output angle value MW.
[0082] Figure 7The basic structure of the multiple position measurement device 8 is shown. The multiple position measurement device includes a measurement scale 12 and three scanning heads 14, 15, and 16.
[0083] The measuring graduations 12 are arranged annularly around the periphery of the shaft 2 and are rotatably connected to the shaft. The measuring graduations 12 can be applied directly to the shaft 2, for example, in the form of a series of magnetic regions. Alternatively, the measuring graduations are arranged on an indexing carrier, which is in turn connected to the shaft 2. If the shaft 2 rotates, the measuring graduations 12 move through the measuring heads 14, 15, and 16.
[0084] Scanning heads 14, 15, and 16 are mounted statically relative to shaft 2, for example, by connecting the scanning heads to the housing of motor spindle 10. A carrier element, as far annular as possible, surrounding shaft 2 serves as the carrier for scanning heads 14, 15, and 16. Advantageously, scanning heads 14, 15, and 16 are arranged at regular angular intervals around the periphery of shaft 2, thereby achieving an ideal (but not mandatory) angular interval of 120º among the three scanning heads 14, 15, and 16.
[0085] In a simpler variant, only two measuring heads may be used, in which case a 180º angular interval is preferred.
[0086] Scanning heads 14, 15, and 16 are suitably designed for scanning the measurement scale 12, thereby obtaining a position-dependent signal from which the angular position of axis 2 can be determined. Different physical scanning principles, particularly magnetic, optical, or inductive scanning principles, are known to be applicable here.
[0087] In the example shown, scanning heads 14, 15, and 16, combined with measurement scale 12, are implemented as an absolute measuring device, that is, digital angle values MW1, MW2, and MW3 are generated from the scanning of measurement scale 12 using scanning heads 14, 15, and 16.
[0088] In an ideal arrangement and during perfect cyclic operation of axis 2, scanning heads 14, 15, and 16 measure the same angular position or have the angular values MW2 and MW3 measured by scanning heads 15 and 16, with a constant bias of 120° or 240° relative to the angular value MW1 of the first scanning head 14.
[0089] Conversely, in actual operation, for example during the milling of workpiece 6 using the motor spindle 10, a force is applied radially to shaft 2, causing the shaft to deflect relative to the fixed scanning heads 14, 15, and 16 (in... Figure 7In the diagram, the force vector F is symbolically shown only to represent the complex force changes that occur during the machining process and as shaft 2 rotates. This force vector moves shaft 2 from its ideal position (with rotation center M as shown by the dashed line) to its working position (with rotation center M'). Because this, in turn, affects the measured angle values MW1, MW2, and MW3, the assessment of the deviations in angle values MW1, MW2, and MW3 caused by the deflection of shaft 2 allows for the inference of the forces or dynamic force changes that occur. In particular, the displacement of shaft 2 can be calculated from the changes in angle values MW1, MW2, and MW3.
[0090] Figure 7 The measurement system shown now has two measuring devices 370 and 380. Measuring device 370 includes a first scanning head 14, which is connected to a data interface 343 via a data transmission channel 351. To initialize the measurement, the data interface 343 sends a request command RQW1 to the scanning head 14, which then performs the measurement and sends an angle value MW1 to the data interface 343. The measurement process is triggered by a measurement pulse MP, which is delivered from the process controller 46 to the measuring device 370, as in the previous example.
[0091] The measuring device 380 includes a second scanning head 15 and a third scanning head 16, which are connected to a bus interface 344 via a data transmission channel 352. The bus interface 344 can communicate with both scanning heads 15 and 16, thereby sending a first request command RQW2 to scanning head 15 and a second request command RQW3 to scanning head 16 to initialize the measurement. Alternatively, a common request command can be set to initialize the measurement and sent to both scanning heads 15 and 16 (broadcast).
[0092] Once at least two digital measuring devices, in this case scanning heads 15 and 16, are to be connected, bus interface 344 can be used. Scanning heads 15 and 16 then send the measured angle values MW2 and MW3 back to bus interface 344. Unlike the measuring device described previously, measuring device 380 is therefore designed to measure and output two measured values, specifically two angle values MW2 and MW3.
[0093] Data interface 343 and bus interface 344 are arranged in control device 340. Furthermore, control device 340 includes process controller 46, data converter 60, and output interface 62 (which are already integrated). Figure 2 (Description) and calculation unit 64.
[0094] In this embodiment, the angle values MW1, MW2, and MW3 measured by the measuring devices 370 and 380 are not directly transmitted to the data converter 60, but are transmitted to the calculation unit 64. The calculation unit 64 calculates the intermediate value Z from the change process of the angle values MW1, MW2, and MW3, which illustrates the change process of the deflection of the shaft 2.
[0095] Similar to the measurement of angle values MW1, MW2, and MW3, an intermediate value Z is calculated in the time grid of the measurement pulse MP. This generates a series of intermediate values, which are transmitted as measured values to the data converter 60, and the data converter converts these intermediate values into angle-based displacement result values EV, i.e., reduced to displacement result values EV for each sector SEC.
[0096] In this embodiment, the angle value MW1 measured by the scanning head 14 is transmitted to the data converter 60 as a reference angle value MW (which is considered for determining the current sector SEC). It is advantageous if the measurement error caused by the displacement of the axis 2 when measuring the angle value MW1 can be tolerated for further evaluation.
[0097] Figure 8 Another embodiment of the measurement system according to the present invention is shown. (Compared to...) Figure 7 The difference in the measurement system lies only in the generation of the reference angle value MW. For this purpose, a second calculation unit 66 is provided in the control device 440, to which the angle values MW1, MW2, and MW3 are fed. The second calculation unit 66 calculates a corrected angle value MW, for example, using the average value formed from the angle values MW1, MW2, and MW3 as an intermediate value. This corrected angle value is then used as the reference angle value in the data converter. In this way, the determination of the current sector SEC in the data converter does not depend on the axis displacement, thereby achieving even higher accuracy in the resulting value.
[0098] Obviously, when calculating the reference angle value MW, the 120º or 240º misalignment between angle values MW1, MW2, and MW3 caused by the arrangement of scanning heads 14, 15, and 16 must be taken into account.
[0099] exist Figure 8 As shown only by dashed lines, the multiple position measuring device 8 may also have an additional scanning head (a fourth scanning head 114 is shown). This additional scanning head can measure the displacement of the axis or the measuring scale 12 perpendicular to the plane of the drawing, if the measuring scale 12 has an indexing structure that allows measurement along that measurement direction. The measurements from the additional scanning head can be directly transmitted to a data converter, where they are converted into angle-based result values, but they can also be transmitted to calculation units 64, 66 for consideration when calculating the intermediate value Z and / or the reference angle value MW.
[0100] Communication with other scanning heads can be achieved via a bus connection as shown (in which case, data interface 343 is implemented as a bus interface) or via a separate data interface.
[0101] Alternatively, each measuring head 14, 15, 16 may also be appropriately designed to measure not only angular values but also displacements perpendicular to the plane of the attached drawing.
[0102] Measuring heads 14, 15, and 16, combined with (absolutely encoded) measuring scales 12, form absolute (digital) measuring devices. It should be noted that, alternatively, incremental measuring scales can also be used, allowing the combination of appropriate measuring heads to form an incremental rotary encoder for evaluating incremental signals. In a consistent expansion scheme, when using a processing interface instead of data interface 343 or bus interface 344, a corresponding... Figure 6A Or, for example, three measuring devices of 6B.
[0103] The present invention is obviously not limited to the described embodiments; rather, it can be alternatively implemented by those skilled in the art within the scope of preferred embodiments.
[0104] Similarly, the invention is not limited to use with machine tools used for milling. The invention can be advantageously used in all machines and facilities where the effects of rotating axes on different components of the machine or facility to be inspected should be analyzed. In addition to machines used for milling, it can be particularly used to inspect machines used for grinding, lathes, or conveying facilities.
Claims
1. A device for processing rotation-dependent measurements, comprising a data converter (60), a process controller (46), and an output interface (62), wherein During a constant time interval of measurement interval (T), a series of measurement values (MW, MX, MS, MW1, MW2, MW3, Z) can be transmitted to the data converter (60), the measurement values depending on the rotation of the shaft (2), and at least one of the measurement values is an angle value (MW, MW1, MW2, MW3) indicating the angular position of the shaft (2). The data converter (60) is designed to divide the rotation of the axis (2) into n sectors (SECs), and, with one of the angle values (MW, MW1) used as a reference angle value, assign the arrived measurement values (MW, MX, MS, MW1, MW2, MW3, Z) to the sector (SEC), and in each rotation of the axis (2), for each series of measurement values (MW, MX, MS, MW1, MW2, MW3, Z) of each sector (SEC), obtain exactly one result value (EW, EX, ES, EV), and The resulting values (EW, EX, ES, EV) can be output to the output interface (62).
2. The device according to claim 1, wherein at least one measuring device is provided, the measuring device comprising an interface (43, 44, 45, 143, 144, 145, 243, 244, 342, 344), a transmission channel (50, 51, 52, 150, 151, 152, 250, 251, 351, 352) and a measuring device, and transmitting a measuring pulse (MP) to the measuring device during a time interval of a measuring interval (T), and the measuring device generating and outputting at least one measuring value (MW, MX, MS, MW1, MW2, MW3) when the measuring pulse (MP) arrives.
3. The device according to claim 2, wherein the at least one measuring device outputs at least one measured value (MW, MX, MS, MW1, MW2, MW3) to the data converter (60).
4. The device according to claim 2, wherein the measuring device outputs at least one measured value (MW1, MW2, MW3) to the computing unit (64, 66), and the computing unit (64, 66) calculates an intermediate value (Z, MW) from the at least one measured value (MW1, MW2, MW3) and outputs the intermediate value to the data converter (60).
5. The device according to any one of claims 2 to 4, wherein the measuring device includes a data interface (43, 44, 45, 342), the data interface being connected to a digital measuring device (5, 15, 20X, 30) via a data transmission channel (50, 51, 52, 351, 352).
6. The device according to any one of claims 2 to 4, wherein the measuring device includes a processing interface (143, 144, 145, 243, 244) connected to an incremental encoder (105, 120, 205, 220) or an analog sensor (130) via a signal transmission channel (150, 151, 152, 250, 251).
7. The device according to any one of claims 2 to 4, wherein the measuring device includes a bus interface (344) connected to at least two digital measuring devices (15, 16) via a data transmission channel (352).
8. A method for processing rotation-dependent measurements using an apparatus, said apparatus comprising a data converter (60), a process controller (46), and an output interface (62), wherein During a constant time interval of measurement interval (T), a series of measurement values (MW, MX, MS, MW1, MW2, MW3, Z) can be transmitted to the data converter (60), the measurement values depending on the rotation of the shaft (2), and at least one of the measurement values is an angle value (MW, MW1, MW2, MW3) indicating the angular position of the shaft (2). In the data converter (60), the rotation of the axis (2) is divided into n sectors (SECs), and with one of the angle values (MW, MW1) used as a reference angle value, the arrived measurement values (MW, MX, MS, MW1, MW2, MW3, Z) are assigned to the sector (SEC). In each rotation of the axis (2), for each series of measurement values (MW, MX, MS, MW1, MW2, MW3, Z) of each sector (SEC), exactly one result value (EW, EX, ES, EV) is obtained. The resulting values (EW, EX, ES, EV) are output to the output interface (62).
9. The method according to claim 8, wherein at least one measuring device is provided, the measuring device comprising interfaces (43, 44, 45, 143, 144, 145, 243, 244, 342, 344), transmission channels (50, 51, 52, 150, 151, 152, 250, 251, 351, 352) and measuring equipment, and in the time interval of the measuring interval (T), a measuring pulse (MP) is transmitted to the measuring device, and the measuring device generates and outputs at least one measuring value (MW, MX, MS, MW1, MW2, MW3) when the measuring pulse (MP) arrives.
10. The method according to claim 9, wherein the at least one measuring device outputs at least one measured value (MW, MX, MS, MW1, MW2, MW3) to the data converter (60).
11. The method according to any one of claims 9 or 10, wherein the measuring device outputs at least one measured value (MW1, MW2, MW3) to the computing unit (64, 66), and the computing unit (64, 66) calculates an intermediate value (Z, MW) from the at least one measured value (MW1, MW2, MW3) and outputs the intermediate value to the data converter (60).
12. The method according to any one of claims 9 or 10, wherein the measuring device includes a data interface (43, 44, 45, 342) connected to a digital measuring device (5, 15, 20X, 30) via a data transmission channel (50, 51, 52, 351, 352).
13. The method according to any one of claims 9 or 10, wherein the measuring device includes a processing interface (143, 144, 145, 243, 244) connected to an incremental encoder (105, 120, 205, 220) or an analog sensor (130) via a signal transmission channel (150, 151, 152, 250, 251).
14. The method according to any one of claims 9 or 10, wherein the measuring device includes a bus interface (344) connected to at least two digital measuring devices (15, 16) via a data transmission channel (352).
15. The method according to any one of claims 8 to 10, wherein the measured values (MW, MX, MS, MW1, MW2, MW3, Z) are assigned to sectors (SEC) according to at least one of the subsequent methods to form the resulting values (EW, EX, ES, EV): Choose either the first measurement value (MW, MX, MS) after the sector change or the last measurement value (MW, MX, MS) before the sector change as the result value (EW, EX, ES). The result value (EW, EX, ES) is formed by averaging all measurements (MW, MX, MS) within a sector (SEC). The angular position of the current sector (SEC) is determined by calculating virtual measurements (EW, EX, ES) from at least two measurements (MW, MX, MS) within the sector (SEC).