US-20260124708-A1 - A SYSTEM FOR TOOL EDGE MONITORING

US20260124708A1US 20260124708 A1US20260124708 A1US 20260124708A1US-20260124708-A1

Abstract

The present disclosure relates to system for shearing material. The system can include a machine including a tool that rotates around an axis at a speed of rotation (f ROT ) for shearing a raw material workpiece; wherein said tool[has at least one tool edge can engage the raw material workpiece; a vibration sensor can generate an analogue measurement signal (S EA ) dependent on mechanical vibrations (V IMP ) emanating from rotation of said tool; a position sensor can generate a position signal indicative of a rotational position of said rotating tool; and status parameter extractor.

Inventors

Tim Sundström

Assignees

S.P.M. INSTRUMENT AB

Dates

Publication Date: 20260507
Application Date: 20231009
Priority Date: 20221009

Claims (17)

1 .- 20 . (canceled)
21 . A system for shearing material, the system comprising: a machine including a tool that rotates around an axis at a speed of rotation for shearing a raw material workpiece, wherein said tool has at least one tool edge configured to engage the raw material workpiece; a vibration sensor configured to generate an analog measurement signal dependent on mechanical vibrations emanating from rotation of said tool; a position sensor configured to generate a position signal indicative of a rotational position of said rotating tool; and one or more hardware processors configured to record: a time sequence of measurement sample values of digital measurement data signal, a time sequence of said position signal values, and time information, said one or more hardware processors further configured to determine at least one tool wear state value indicative of a tool wear state of said tool.
22 . The system according to claim 21 , wherein said one or more hardware processors further comprise: a tool speed detector, a speed variation compensatory decimator and a Fast Fourier Transformer; wherein the tool speed detector is configured to receive the time sequence of measurement sample values and to receive the time sequence of said position signal values, and determine, for a received measurement sample value, a momentary rotational speed of the tool; and the tool speed detector is configured to output or deliver a set of signals, wherein the set of signals includes a measurement signal sample value, and a position signal sample value, and said determined momentary rotational tool speed; and wherein the speed variation compensatory decimator is configured to receive the set of signals output of the tool speed detector and to generate samples of the set of signals for predetermined fractions of tool revolution, thereby generating signals at a same orientation of the tool for each revolution irrespective of rotational speed; and wherein the Fast Fourier Transformer is configured to calculate amplitudes for at least two orders of a fundamental frequency based on the output of the speed variation compensatory decimator.
23 . The system according to claim 21 , wherein the one or more hardware processors further comprises: a tool speed detector, a speed variation compensatory decimator, a time synchronous Averager TSA, and a Fast Fourier Transformer; wherein the tool speed detector is configured receive the time sequence of measurement sample values and to determine a momentary rotational tool speed of the tool and output; the speed variation compensatory decimator is configured to receive the output of the tool speed detector and to generate sample of a set of signals for predetermined fractions of tool revolution, thereby generating signals at a same orientation of the tool for each revolution irrespective of rotational speed; wherein a time synchronous averager is arranged to receive the output of the speed variation compensatory decimator and to calculate an average measurement sample value based on received measurement sample values corresponding to the same tool position for at least two revolutions; and wherein the Fast Fourier Transformer is configured to calculate the magnitudes for at least two orders of the fundamental frequency based on the averaged measurement sample values calculated by the time synchronous averager.
24 . The system according to claim 21 , wherein the one or more hardware processors further comprises: a tool speed detector, a speed variation compensatory decimator, and a time synchronous Averager; wherein the tool speed detector is configured receive the time sequence of measurement sample values and to determine a rotational speed of the tool and output a set of signals, wherein the set of signals includes a measurement signal sample value, and a position signal sample value, and said determined momentary rotational tool speed; wherein the speed variation compensatory decimator is configured to receive the output of the tool speed detector and to generate sample of the set of signals for each predetermined fraction of tool revolution, thereby generating signals at the same orientation of the tool for each revolution irrespective of rotational speed; wherein the time synchronous Averager is arranged to receive the output of the speed variation compensatory decimator and to calculate an average measurement sample value based on received measurement sample value corresponding to the same tool position for at least two revolutions.
25 . The system according to claim 23 , wherein the one or more hardware processors are further configured to: output the average measurement sample value and corresponding positional signal values calculated by the time synchronous Averager; wherein an average measurement sample value is based on a time sequence of measurement sample values from at least two revolutions of the tool.
26 . The system according to claim 25 , further comprising a user interface for presenting tool wear state values; and wherein said status parameter extractor is arranged to provide, to said user interface, said averaged sample value and a corresponding positional signal value calculated by the TSA and/or the frequency magnitudes and corresponding frequency bins calculated by Fast Fourier Transformer; and wherein the user interface is arranged to receive and present said values indicative of the tool wear state.
27 . A method of operating a machine including a tool having a tool edge part for shaping and/or shearing a raw material work piece when a) the raw material work piece rotates, at a speed of rotation, in relation to the tool edge part so as to generate a product work piece, or when b) the tool edge part rotates, at a speed of rotation, in relation to the raw material work piece so as to generate a product work piece, thereby causing a vibration having a first repetition frequency dependent on said speed of rotation; the method comprising: receiving a vibration signal indicative of said vibration; detecting, in said vibration signal, a vibration signal signature; generating frequency spectrum data based on said vibration signal signature, generating at least two amplitude values based on said frequency spectrum data; wherein a first amplitude value is indicative of a magnitude of a sine wave whose signal frequency is said first repetition frequency; and a second amplitude value is indicative of a magnitude of a sine wave whose signal frequency is an integer multiple of said first repetition frequency; generating at least one relation value based on said at least two amplitude values; wherein said at least one relation value is indicative of a wear state of the tool edge part.
28 . The method according to claim 27 , further comprising: receiving a reference signal, said reference signal comprising a speed signal indicative of said speed of rotation, and/or a position signal indicative of a rotational position; and generating frequency spectrum data based on said vibration signal signature and said reference signal.
29 . The method according to claim 27 , further comprising: recording, by one or more hardware processors, a time sequence of measurement sample values of said vibration signal, a time sequence of said position signal sample values, and time information such that an individual measurement sample value can be associated with data indicative of time and rotational position, determining, by the one or more hardware processors, at least one tool wear state value indicative of a tool wear state of said tool based on said recorded time sequence of measurement sample values, said recorded time sequence of position signal sample values, and said recorded time information.
30 . The method according to claim 27 , further comprising: determining, by a speed detector, a momentary rotational speed of the tool; and delivering, by said speed detector, a set of signals, wherein the set of signals includes a measurement signal sample value, and a position signal sample value, and said determined momentary rotational tool speed; and receiving, by a speed variation compensatory decimator, the set of signals; and generating, by said speed variation compensatory decimator, samples of the set of signals for a predetermined number of rotational positions, thereby generating signals at the same rotational orientation for each revolution irrespective of rotational speed; and calculating, by a Fast Fourier Transformer, amplitudes for at least two orders of the fundamental frequency based on the output of the speed variation compensatory decimator, wherein said calculated amplitudes comprise said first amplitude value and said second amplitude value.
31 . An apparatus for monitoring of a tool wear state of a machine including a tool having a tool edge part for shaping and/or shearing a raw material work piece when a) the raw material work piece rotates, at a speed of rotation, in relation to the tool edge part and generate a product work piece, or when b) the tool edge part rotates, at a speed of rotation, in relation to the raw material work piece and generate a product work piece, thereby causing a vibration having a first repetition frequency dependent on said speed of rotation; the apparatus comprising: a data processing device which, when it runs a computer program, causes the apparatus to carry out the method of claim 27 .
32 . The apparatus according to claim 31 , further comprising: a computer readable medium; and a computer program, stored on said computer readable medium, wherein said data processing device is coupled to said computer readable medium; the computer program comprising computer program code adapted to perform the method according to claim 17 when said computer program runs on said data processing device.
33 . The apparatus according to claim 31 , wherein: said data processing device comprises a Digital Signal Processor.
34 . The apparatus according to claim 31 , wherein: said data processing device comprises a Field Programmable Gate Array circuit.
35 . The apparatus according to claim 31 , wherein: said data processing device is a combination of a processor and a Field Programmable Gate Array circuit.
36 . A computer program product loadable into a digital memory of an apparatus having a data processing unit, the computer program product comprising software code adapted to perform the method according to claim 27 when said computer program product runs on a data processing unit.

Description

TECHNICAL FIELD The present invention relates to the field of a machine including a tool for shearing and/or shaping a raw material workpiece and to the monitoring of a machine including a tool for shearing and/or shaping a raw material workpiece. The present invention also relates to a method for generating information relating to a tool wear state of a machine including a tool for shearing and/or shaping a raw material workpiece, and to the field of control of a machine including a tool for shearing and/or shaping a raw material workpiece. The present invention also relates to a method of operating a shearing process in a machine including a tool for shearing and/or shaping a raw material workpiece, and to an apparatus for monitoring of a tool wear state of a machine including a tool for shearing and/or shaping a raw material workpiece. The present invention also relates to an apparatus for controlling a tool wear state of a machine including a tool for shearing and/or shaping a raw material workpiece. The present invention also relates to a computer program for monitoring of a tool wear state of a machine including a tool for shearing and/or shaping a raw material workpiece. The present invention also relates to a computer program for controlling a tool wear state of a machine including a tool for shearing and/or shaping a raw material workpiece. DESCRIPTION OF RELATED ART In some industries, such as in the forestry industry, there is a need to shear material that comes in large pieces to reduce the size of individual pieces of the received material. A machine including a tool for shearing and/or shaping a raw material workpiece can achieve shearing of material. A machine including a tool for shearing and/or shaping a raw material workpiece includes SUMMARY In view of the state of the art, a problem to be addressed is how to generate improved information relating to a tool wear state of a machine including a tool for shearing and/or shaping a raw material workpiece and/or how to obtain an improved method of operating a shearing process in a machine including a tool for shearing and/or shaping a raw material workpiece. This problem is addressed by examples presented herein. BRIEF DESCRIPTION OF THE DRAWINGS For simple understanding of the present invention, it will be described by means of examples and with reference to the accompanying drawings, of which FIG. 1A shows a somewhat diagrammatic and schematic side view of a system including a machine including a tool for shearing and/or shaping a raw material workpiece. FIG. 1C is a block diagram illustrating a machine including a tool for shearing and/or shaping a raw material workpiece as a box receiving a number of inputs and generating a number of outputs. FIG. 2, shows another example of a cross-sectional view taken along line A-A of FIG. 1A FIG. 3 is a schematic block diagram of an example of the analysis apparatus shown in FIG. 1. FIG. 4 is a simplified illustration of the program memory and its contents. FIG. 5 is a block diagram illustrating an example of the analysis apparatus. FIG. 6A is an illustration of a signal pair S(i) and P(i) as delivered by an A/D converter. FIG. 6B is an illustration of a sequence of the signal pair S(i) and P(i) as delivered by the A/D converter. FIG. 7 is a block diagram that illustrates an example of a part of a status parameter extractor. FIG. 8 is a simplified illustration of an example of a memory and its contents. FIG. 9 is a flow chart illustrating an example of a method of operating the status parameter extractor of FIG. 7. FIG. 10 is a flow chart illustrating an example of a method for performing step S#40 of FIG. 9. FIG. 11 is a flow chart illustrating another example of a method. FIG. 12 is a flow chart illustrating another example of a method for performing step S#40 of FIG. 9. FIG. 13 is a graph illustrating a series of temporally consecutive position signals P1, P2, P3, . . . , each position signal P being indicative of a full revolution of the monitored tool. FIGS. 15A and 15B are a block diagrams illustrating examples of a status parameter extractors. FIGS. 16A and 16B illustrative examples of visual indications of analysis results relating to the time domain. FIGS. 17A and 17B illustrative examples of visual indications of analysis results relating to the frequency domain. FIG. 18 illustrative an example interaction between tool edge and raw material. FIGS. 19A, 19B and 19C illustrative examples of different types of machines for shearing and/or shaping a raw material workpiece. FIG. 20 is a block diagram of an example of compensatory decimator. FIG. 21 is a flow chart illustrating an embodiment of a method of operating the compensatory decimator of FIG. 20. FIGS. 22A, 22B and 22C illustrate a flow chart of an embodiment of a method of operating the compensatory decimator of FIG. 20. FIG. 26 shows a somewhat diagrammatic and schematic top view of yet another embodiment of a system including a machine in