CA3130130A1 - Anti-vibration control system for industrial machines - Google Patents

Abstract

An anti-vibration control system is provided, the anti-vibration control system including: an exterior acoustic sensor system which includes an acoustic sensor; a multi-sensor fusion module; an exterior housing that houses the exterior acoustic sensor system and the multi-sensor fusion module; a first interior acoustic sensor system and a second interior acoustic sensor system, each including an acoustic sensor, and an acoustic signal processing module, the acoustic signal processing module in wired or wireless communication with the multi-sensor fusion module; a first interior housing that houses the first interior acoustic sensor system; a second interior housing that houses the second interior acoustic sensor system; and a signal processing module which includes a wireless radio. A method of reducing or eliminating chatter in a rotating tool industrial machine is also provided.

Description

ANTI-VIBRATION CONTROL SYSTEM FOR INDUSTRIAL MACHINES
FIELD
The present technology is directed to a system for monitoring machining equipment for vibration and for controlling vibration. More specifically, it is an autonomous system that measures vibration and adjusts the machining equipment operating parameters to reduce or eliminate vibration, thereby improving productivity.
BACKGROUND
Chatter vibrations are one of the most important factors limiting the productivity of machining industry. They cause poor surface quality, increase tool wear and can cause damages to the machine tool.
There are numerous approaches to reducing chatter. For example, United States Patent Application Publication No. 20020146296 discloses that in milling operations, periodically sensed vibration signals synchronous with tool revolution enables a determination of whether the tool returns to approximately the same position each revolution.
If so, stability is indicated by tightly grouped values of the periodically sensed vibration signal. If the tool does not return to the same position, spread in the value of the periodically sampled vibration signals is produced thereby indicating chatter conditions. Variance values may be calculated and displayed; histograms may be produced and displayed;
corrective action, if needed, may be taken in response to the variance values and/or histogram.
Nominal (or commanded) spindle speed, while not necessarily exactly synchronous with actual tool rotation, is entirely adequate to trigger samples and achieve clear indication of the presence or absence of chatter. This system is not autonomous and requires an operator.
United States Patent Application Publication No. 20160116899 discloses a system, method, and computer-readable medium for providing a user interface. The system includes circuitry configured to generate chatter information based on sensor data collected from a machining operation of a machine performed at a previously selected tool speed setting. The chatter information includes a chatter level value and a chatter frequency value. A plurality of different candidate tool speed settings is determined based Date Recue/Date Received 2021-09-08 on the generated chatter frequency value from the machining operation. The circuitry generates the user interface that includes a plurality of different tool speed settings, including the previously selected tool speed setting and the plurality of different candidate tool speed settings for selection by a user. The user interface is configured to indicate the chatter level value for the previously selected. This system requires an operator and is not autonomous.
United States Patent Application Publication No. 20100104388 discloses a vibration suppressing method and a vibration suppressing device. After a tool is attached to a main spindle, a modal parameter of the tool or a workpiece is computed. Thereafter, a relation between chatter frequency and phase difference is calculated as an approximation formula based on the obtained modal parameter and machining conditions. If chatter vibration occurs after initiation of the machining, a chatter frequency corresponding to a target phase difference is obtained using the approximation formula, and based on the obtained chatter frequency, the number of tool flutes and the main spindle rotation speed, the optimum rotation speed is calculated. The rotation speed of the main spindle is then changed in accordance with the obtained optimum rotation speed. There is no capability for machine learning.
Chinese Patent Application No. 104898565 discloses a chatter database system, which includes a central chatter database, which is fed with data corresponding to the machining and chatter conditions of machining tools, particularly a milling, turning, drilling or boring machine. The invention is characterized by the features that the data fed to the central chatter database is obtained and collected from at least two individual machining tools included in the chatter database system. Whereby the data is sent to the central chatter database via a data connection, preferably via a secured network, to generate chatter stability maps based on real encountered conditions. There is no capability for reducing chatter autonomously.
As disclosed in Science Direct 11th CIRP Conference on Intelligent Computation in Manufacturing Engineering, CIRP ICME '17 "Online learning of stability lobe diagrams in milling" (Jens Friedricha, Jonas Torzewskia, Alexander Verla) the productivity of milling machines is limited by chatter vibrations. Stability lobe diagrams (SLD) allow the

2 Date Recue/Date Received 2021-09-08 selection of suitable process parameters to maximize the productivity.
However, the calculation of SLDs is very time-consuming and requires complex experiments.
In this article a new online learning method is presented, which allows the calculation of SLDs during the production process. The algorithm is a combination of reinforcement learning and nearest-neighbor-classification and allows the estimation of the stability border based on measured vibration signals during machining. The proposed algorithm is capable of being continuously trained with sorted input data. A trust criterion is introduced, which allows judging the prediction quality of the algorithm. The algorithm is validated with analytical benchmark functions and with a 2-DOF milling stability simulation.
maximizing the productivity. There exist several possibilities of generating SLDs. The SLD can be calculated based on the stability of the mathematical model with time delay.
This demands a very accurate model. An experimental approach avoids the modelling by applying test cuts for different spindle speeds and cutting depths. The model-based as well as the experimental approach suffer from the additional effort of identifying the model or the SLD. Moreover, the SLD is only valid for the timeframe, in which the experiments were performed, as the machine behavior can change over time. In this paper, an approach to continuously learn the SLD during productive milling is presented.
The learning algorithm allows the prediction of the stability border based on measured vibration signals. The application during productive milling leads to sorted input data and an incomplete training set. The algorithm can be trained with incomplete, sorted training data and the proposed trust criterion allows to judge the prediction reliability.
What is needed is a system for monitoring machining tools for vibration and correcting the operating conditions to reduce or eliminate vibration. It would be preferable if it could discriminate between background vibration and noise and vibration within the enclosed work envelope. It would be further preferable if the sensor data were communicated wirelessly to the computing unit of the system. It would be further preferable if the system could autonomously alter the operating conditions of the machine to reduce or eliminate the vibration in response to an exceedance in vibration. It would be further preferable if the system included a learning module. It would be further preferable if the computing unit included software configured to analyze the sensor data, archive the sensor data, archive the analyzed data and develop predictive models using the analyzed data.

3 Date Recue/Date Received 2021-09-08 SUMMARY
The present technology is a system for monitoring machining tools for vibration and correcting the operating conditions to reduce or eliminate vibration. It can discriminate between background vibration and noise and vibration within the enclosed work envelope.
The sensor data are communicated wirelessly to the computing unit of the system. The system can autonomously alter the operating conditions of the machine to reduce or eliminate the vibration in response to an exceedance in vibration. The system includes a learning module. In order to learn, the computing unit includes software configured to analyze the sensor data, archive the sensor data, archive the analyzed data and develop correction protocols using the analyzed data.
In one embodiment an anti-vibration control system is provided for use with an industrial machine with a rotating tool, an interior, an exterior and a control panel, the anti-vibration control system comprising: an exterior acoustic sensor system which includes an acoustic sensor and an exterior acoustic signal processing module, which is in an external printed circuit board (PCB) and is in communication with the acoustic sensor; an exterior housing that is configured for placement on the exterior of the industrial machine and houses the exterior acoustic sensor system; a first interior acoustic sensor system which includes a first interior acoustic sensor and a first acoustic signal processing module which is in communication with the first interior acoustic sensor; a second interior acoustic sensor system which includes a second interior acoustic sensor and a second acoustic signal processing module which is in communication with the second interior acoustic sensor; a first interior housing that is configured for placement in the interior of the industrial machine and houses the first interior acoustic sensor system; a second interior housing that is configured for placement in the interior of the industrial machine and houses the second interior acoustic sensor system; and a signal processing and control module which is configured to receive and process acoustic signals from each of the acoustic signal processing modules and send instructions to the control panel of the industrial machine.

4 Date Recue/Date Received 2021-09-08 In the anti-vibration control system, the signal processing and control module may be configured to process acoustic signals from each acoustic sensor system to minimize acoustic signals arising from ambient noise and maximize acoustic signals arising from machine operations.
The anti-vibration control system may further comprise a computing unit which includes the signal processing and control module.
In the anti-vibration control system, the signal processing and control module may be configured to detect features of the acoustic signals that are indicative of chatter.
In the anti-vibration control system, the signal processing and control module may be configured to correlate operating conditions of the industrial machine with features of the acoustic signals that are indicative of chatter and to develop a process stability database.
In the anti-vibration control system, the signal processing and control module may be configured to learn from the process stability database to provide a learned stability database.
In the anti-vibration control system, the signal processing and control module may be configured to reduce or eliminate chatter using the learned stability database.
In another embodiment, a combination comprising an anti-vibration control system and an industrial machine with a rotating tool is provided, the industrial machine including an exterior, an interior and a control panel, the anti-vibration control system including: an exterior acoustic sensor system which includes an acoustic sensor and an exterior acoustic signal processing module, which is in an external printed circuit board (PCB) and is in communication with the acoustic sensor; an exterior housing that is on the exterior of the industrial machine and houses the exterior acoustic sensor system; a first interior acoustic sensor system which includes a first interior acoustic sensor and a first acoustic signal processing module in communication with the first interior acoustic sensor;
a second interior acoustic sensor system which includes a second interior acoustic sensor and a second acoustic signal processing module which is in communication with the second interior acoustic sensor; a first interior housing that is in the interior of the industrial machine and houses the first interior acoustic sensor system; a second interior Date Recue/Date Received 2021-09-08 housing that is in the interior of the industrial machine and houses the second interior acoustic sensor system; and a signal processing and control module which is configured to receive and process acoustic signals from each of the acoustic signal processing modules and send instructions to the control panel of the industrial machine.
In the combination, the acoustic signal processing modules of each of the first interior acoustic sensor system and the second interior acoustic sensor system may be in wireless communication with the signal processing and control module.
In the combination, the exterior acoustic sensor system, the first interior acoustic sensor system and the second interior acoustic sensor system may each include a pair of acoustic sensors.
In the combination, the acoustic sensors may be microelectromechanical acoustic sensors.
In another embodiment, a method is provided for reducing or eliminating chatter in an industrial machine with a rotating tool, the method comprising:
-selecting an anti-vibration control system, the anti-vibration control system including: an exterior acoustic sensor system which includes an exterior acoustic sensor and an exterior signal processing module; an exterior housing that houses the exterior acoustic sensor system; a first interior acoustic sensor system, including a first interior acoustic sensor and a first acoustic signal processing module; a second interior acoustic sensor system, including a second interior acoustic sensor, and a second acoustic signal processing module; a first interior housing that houses the first interior acoustic sensor system; a second interior housing that houses the second interior acoustic sensor system; and a signal processing and control module which is in wired or wireless communication with the exterior, the first interior and the second interior signal processing modules;
-attaching the exterior housing to an exterior surface of the industrial machine and attaching the first and the second interior housing to an interior surface of the industrial machine;

Date Recue/Date Received 2021-09-08 -processing a workpiece with the industrial machine and concomitantly, the anti-vibration control system autonomously: sensing acoustic signals; processing the acoustic signals; and sending instructions to the control panel of the industrial machine to modify its operating parameters, thereby reducing or eliminating chatter.
In the method, the instructions may be to modify the speed of the spindle of the industrial machine.
In the method, the instructions may be to modify the depth of cut.
In the method, the instructions may be to modify both the speed of the spindle and the depth of the cut.
In the method, the multi-sensor fusion module may process acoustic signals from each acoustic sensor system to minimize acoustic signals arising from ambient noise and maximize acoustic signals arising from processing a workpiece.
In the method, the signal processing modules may each transmit a signal to the signal processing and control module.
In the method, the signal processing and control module may detect features of the signals that are indicative of chatter.
In the method, the signal processing and control module may correlate operating conditions of the industrial machine with features of the signals that are indicative of chatter and develops a process stability database.
In the method, the signal processing and control module may learn from the process stability database to provide a learned stability database.
In the method, the signal processing and control module may reduce or eliminate chatter using the learned stability database to determine instructions for the control panel of the industrial machine.
In another embodiment, an anti-vibration control system is provided for use with an industrial machine with a rotating tool, an interior, an exterior and a control panel, the anti-Date Recue/Date Received 2021-09-08 vibration control system comprising: an exterior acoustic sensor system which includes an acoustic sensor and an external printed circuit board (PCB); a multi-sensor fusion module which includes the external PCB and a wireless radio; an exterior housing that is configured for placement on the exterior of the industrial machine and houses the exterior acoustic sensor system and the multi-sensor fusion module; a first interior acoustic sensor system and a second interior acoustic sensor system, each including an acoustic sensor, an internal PCB, a power supply module and an acoustic signal processing module, the acoustic signal processing module in wired or wireless communication with the multi-sensor fusion module; a first interior housing that is configured for placement in the interior of the industrial machine and houses the first interior acoustic sensor system; a second interior housing that is configured for placement in the interior of the industrial machine and houses the second interior acoustic sensor system; and a signal processing and control module which includes a wireless radio and is configured to receive and process acoustic signals from the multi-sensor fusion module and send instructions to the control panel of the industrial machine.
In the anti-vibration control system, the multi-sensor fusion module may be configured to process acoustic signals from each acoustic sensor system to minimize acoustic signals arising from ambient noise and maximize acoustic signals arising from machine operations.
In the anti-vibration control system, wherein the multi-sensor fusion module may be configured to transmit a summary signal to the signal processing module.
In the anti-vibration control system, the signal processing and control module may be configured to detect features of the summary signal that are indicative of chatter.
In the anti-vibration control system, the signal processing and control module may be configured to correlate operating conditions of the industrial machine with features of the summary signal that are indicative of chatter and to develop a process stability database.
In the anti-vibration control system, the signal processing and control module may be configured to learn from the process stability database to provide a learned stability database.

Date Recue/Date Received 2021-09-08 In the anti-vibration control system, the signal processing and control module may be configured to reduce or eliminate chatter using the learned stability database.
In another embodiment, a combination comprising an anti-vibration control system and an industrial machine with a rotating tool is provided, the industrial machine including an exterior, an interior and a control panel, the anti-vibration control system including an exterior acoustic sensor system which includes an acoustic sensor and an external printed circuit board (PCB); a multi-sensor fusion module which includes the external PCB
and a wireless radio; an exterior housing that is located on the exterior of the industrial machine and houses the exterior acoustic sensor system and the multi-sensor fusion module; a first interior acoustic sensor system and a second interior acoustic sensor system, each including an acoustic sensor, an internal PCB, a power supply module and an acoustic signal processing module, the acoustic signal processing module in wired or wireless communication with the multi-sensor fusion module; a first interior housing that is located in the interior of the industrial machine and houses the first interior acoustic sensor system; a second interior housing that is located in the interior of the industrial machine and houses the second interior acoustic sensor system; and a signal processing and control module which includes a wireless radio and is configured to receive and process acoustic signals from the multi-sensor fusion module and send instructions to the control panel of the industrial machine.
In the combination, the acoustic signal processing modules of each of the first interior acoustic sensor system and the second interior acoustic sensor system may be in wireless communication with the multi-sensor fusion module.
In the combination, the exterior acoustic sensor system, the first interior acoustic sensor system and the second interior acoustic sensor system may each include a pair of acoustic sensors.
In the combination, the acoustic sensors may be microelectromechanical acoustic sensors.
In another embodiment, a method of reducing or eliminating chatter in an industrial machine with a rotating tool is provided, the method comprising:

Date Recue/Date Received 2021-09-08 -selecting an anti-vibration control system, the anti-vibration control system including: an exterior acoustic sensor system which includes an acoustic sensor;
a multi-sensor fusion module; an exterior housing that houses the exterior acoustic sensor system and the multi-sensor fusion module; a first interior acoustic sensor system and a second interior acoustic sensor system, each including an acoustic sensor, and an acoustic signal processing module, the acoustic signal processing module in wired or wireless communication with the multi-sensor fusion module;
a first interior housing that houses the first interior acoustic sensor system;
a second interior housing that houses the second interior acoustic sensor system; and a signal processing and control module which includes a wireless radio;
-attaching the exterior housing to an exterior surface of the industrial machine and attaching the first and the second interior housing to an interior surface of the industrial machine;
-processing a workpiece with the industrial machine and concomitantly, the anti-vibration control system autonomously: sensing acoustic signals; processing the acoustic signals; and sending instructions to the control panel of the industrial machine to modify its operating parameters, thereby reducing or eliminating chatter.
In the method, the instructions may be to modify the speed of the spindle of the industrial machine.
In the method, the instructions may be to modify the depth of cut.
In the method, the instructions may be to modify both the speed of the spindle and the depth of the cut.
In the method, the multi-sensor fusion module may process acoustic signals from each acoustic sensor system to minimize acoustic signals arising from ambient noise and maximize acoustic signals arising from processing a workpiece.
In the method, the multi-sensor fusion module may transmit a summary signal to the signal processing module.
3.0 Date Recue/Date Received 2021-09-08 In the method, the signal processing and control module may detect features of the summary signal that are indicative of chatter.
In the method, the signal processing and control module may correlate operating conditions of the industrial machine with features of the summary signal that are indicative of chatter and develops a process stability database.
In the method, the signal processing and control module may learn from the process stability database to provide a learned stability database.
In the method, the signal processing and control module may reduce or eliminate chatter using the learned stability database to determine instructions for the control panel of the industrial machine.
FIGURES
Figure 1 is a perspective view of an exemplary system of the present technology with a partial cutaway to show the internal acoustic sensor systems in the work envelope.
Figure 2 is a block diagram of a system diagram for a machine with a rotating tool.
Figure 3 is a block diagram for an alternative embodiment of a machine with a rotating tool.
Figure 4 is a block diagram of another alternative embodiment of a machine with a rotating tool.
Figure 5 is a block diagram for another alternative wired embodiment.
Figure 6 is a block diagram for another alternative wireless embodiment.
DESCRIPTION
Techniques operating according to the principles described herein may be implemented in any suitable manner. The processing and decision blocks of the flow charts above represent steps and acts that may be included in algorithms and/or circuitry that carry out these various processes. Unless otherwise indicated herein, the particular sequence of steps and/or acts described in each flow chart is merely illustrative of the algorithms that Date Recue/Date Received 2021-09-08 may be implemented and can be varied in implementations and embodiments of the principles described herein.
The acts performed as part of a method may be ordered in any suitable way.
Accordingly, embodiments may be constructed in which acts are performed in an order different than illustrated, which may include performing some acts simultaneously, even though shown as sequential acts in illustrative embodiments.
Except as otherwise expressly provided, the following rules of interpretation apply to this specification (written description and claims): (a) all words used herein shall be construed to be of such gender or number (singular or plural) as the circumstances require; (b) the singular terms "a", "an", and "the", as used in the specification and the appended claims include plural references unless the context clearly dictates otherwise; (c) the antecedent term "about" applied to a recited range or value denotes an approximation within the deviation in the range or value known or expected in the art from the measurements method; (d) the words "herein", "hereby", "hereof", "hereto", "hereinbefore", and "hereinafter", and words of similar import, refer to this specification in its entirety and not to any particular paragraph, claim or other subdivision, unless otherwise specified; (e) descriptive headings are for convenience only and shall not control or affect the meaning or construction of any part of the specification; and (f) "or" and "any" are not exclusive and "include" and "including" are not limiting. Further, the terms "comprising," "having,"
"including," and "containing" are to be construed as open-ended terms (i.e., meaning "including, but not limited to,") unless otherwise noted.
Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. Where a specific range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range, is included therein. All smaller sub ranges are also included. The upper and lower limits of these smaller ranges are also included therein, subject to any specifically excluded limit in the stated range.

Date Recue/Date Received 2021-09-08 Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the relevant art.
Although any methods and materials similar or equivalent to those described herein can also be used, the acceptable methods and materials are now described.
DEFINITIONS
Autonomous, non-interfering dynamic monitoring and correcting ¨ in the context of the present technology, autonomous, non-interfering dynamic monitoring and correcting is effected by sensors and a printed circuit board that are integrated into the tool and operate without the assistance of a machine operator.
Computing unit ¨ in the context of the present technology, a computing unit includes at least one processor, and computer-readable storage media. A computing unit may be, for example, a desktop or laptop personal computer, a personal digital assistant (PDA), a smart mobile phone, a server, or any other suitable computing unit. A
network adapter may be any suitable hardware and/or software to enable the computing unit to communicate wired and/or wirelessly with any other suitable computing unit over any suitable computing network. The computing network may include wireless access points, switches, routers, gateways, and/or other networking equipment as well as any suitable wired and/or wireless communication medium or media for exchanging data between two or more computers, including the Internet. Computer-readable media may be adapted to store data to be processed and/or instructions to be executed by processor.
The processor enables processing of data and execution of instructions. The data and instructions may be stored on the computer-readable storage media (memory).
A computing unit may additionally have one or more components and peripherals, including input and output devices. Examples of output devices that can be used to provide a user interface include printers or display screens for visual presentation of output and speakers or other sound generating devices for audible presentation of output.
Examples of input devices that can be used for a user interface include keyboards, and pointing devices, such as mice, touch pads, and digitizing tablets.

Date Recue/Date Received 2021-09-08 Communication network ¨ in the context of the present technology a communication network includes but is not limited to a wireless fidelity (Wi-Fi [IEEE
802.11]) network, a light fidelity (Li-Fi) network, a satellite network, the internet, a cellular data network, a local area network (LAN), Bluetooth0, a wireless local area network (WLAN), or any combination thereof. The network adapter of the computing unit communicates via the communication network.
Hammer Tap Test ¨ in the context of the present technology, hammer tap testing or tap testing, also known as modal testing, is an experimental method that is used to excite the machine-tool system in order to extract its harmonic information such as natural frequencies, modal masses, modal damping ratios and mode shapes. This is normally done in static conditions, using the impact hammer as the excitation mechanism, and an accelerometer as the sensor. In theory, the tool tip should be given a perfect impulse which excites a range of frequencies with a constant amplitude in an infinitely short duration. This allows the user to obtain a clean frequency response function (FRF) over the full frequency range of interest.
Stability lobe diagrams (SLD) ¨ stability lobe diagrams allow the selection of suitable process parameters to maximize the productivity.
Chatter ¨ in the context of the present technology chatter is a result of vibration.
DETAILED DESCRIPTION
As shown in Figure 1 an anti-vibration control system, generally referred to as 6 is for an industrial machine, generally referred to as 8. The anti-vibration control system 6 includes a signal processing and control module 10 that communicates with a control panel 12 of the industrial machine and three acoustic sensor systems, an external acoustic sensor system 14 and two internal acoustic sensor systems 16, 18. The external acoustic sensor system14 is affixed to an exterior surface 20 of the industrial machine 8 and is configured to sense ambient noise. The two internal acoustic sensory systems 16, 18 are housed within the work envelope 22 and are configured to sense acoustic signals associated with processing. They are located on opposite sides of the work envelope 22 to one another.

Date Recue/Date Received 2021-09-08 The industrial machine 8 may be a milling machine, a cutting machine or a turning machine and the tool 24 may be a cutting tool or a rotating tool.
As shown in Figure 2, the acoustic sensor systems 14, 16, 18 each include a printed circuit board (PCB) 30 and a microelectromechanical acoustic sensor 32. The internal acoustic sensor systems 16, 18 each further include a wireless radio 34, which may be a Bluetooth0 radio, a power supply module 36 and an acoustic signal processing module 38. In one embodiment the power supply module 36 is configured to retain a battery and includes a PCB 40 to monitor charge, discharge rate and other variables. In another embodiment, the power supply module 36 is a radio frequency wireless charging unit.
Each acoustic sensor system 14, 16, 18 is protected with an acoustically transparent but hydrophobic membrane such that an Ingress Protection Rating of 67 or greater is achieved, while not degrading the integrity of the acoustic signals. The internal acoustic sensor systems 16, 18 are each housed in a housing 42. The microelectromechanical acoustic sensors 32 are each in wireless or wired communication with an acoustic signal processing module 38 via the PCB 30. The external acoustic sensor system 14 is housed in a housing 48 on the exterior surface 20 of the industrial machine 8. It is in wired communication with a multi-sensor fusion module 50. The multi-sensor fusion module 50 includes the PCB 30 or may have a separate PCB, a semiconductor 54, a power supply module 56 and a wireless signal transmission module 58 which may be a Bluetooth0 radio. It is housed in the housing 48 on the exterior surface 20 of the industrial machine 8. The multi-sensor fusion module 50 communicates with each acoustic signal processing module 38 (and directly with the exterior acoustic sensor system 14) and with a computing unit 62, which includes the signal processing and control module 10. The signal sent from the multi-sensor fusion module 50 is a summary signal of the three separate acoustic signals from the three acoustic sensor systems 14, 16, 18.
The signal processing and control module 10 communicates wirelessly with the control panel 12.
In an alternative embodiment shown in Figure 3, the acoustic sensor systems 14, 16, 18 each include a printed circuit board (PCB) 30 and a microelectromechanical acoustic sensor 32. The internal acoustic sensor systems 16, 18 further include a power supply module 36 and an acoustic signal processing module 38. The internal acoustic sensor Date Recue/Date Received 2021-09-08 systems 16, 18 are each housed in a housing 42. Each acoustic sensor system 14, 16, 18 is protected with an acoustically transparent but hydrophobic membrane such that an Ingress Protection Rating of 67 or greater is achieved, while not degrading the integrity of the acoustic signals. The internal acoustic sensor systems 16, 18 are each in wired communication with the multi-sensor fusion module 50. The external acoustic sensor system 14 is in wired communication with a multisensory fusion module 50, both of which are housed in the housing 46 on the exterior surface 20 of the industrial machine 8. The multi-sensor fusion module 50 includes a PCB 52, a semiconductor 54, a power supply module 56 and a wireless signal transmission module 58 which may be a Bluetooth0 radio. The multi-sensor fusion module 50 communicates with each acoustic signal processing module 38 (and directly with the exterior acoustic sensor system 14) and with a computing unit 62 which includes the signal processing and control module 10. The multi-sensory fusion module 50 is configured to process the signals from each acoustic sensor system 14, 16, 18 in order to minimize the signal arising from ambient noise in the environment and maximize the signal arising from machine operations. The signal processing and control module 10 communicates wirelessly with the control panel 12.
In an alternative embodiment of the systems of Figures 2 and 3, the acoustic sensor systems 14, 16, 18 each include a pair of microelectromechanical acoustic sensors 32 to provide a directional microphone.
In an alternative embodiment of the systems of Figures 2 and 3, as shown in Figure 4, the external acoustic sensor system 14 includes the PCB 30, the microelectromechanical acoustic sensor 32, a power supply module 70 and a wireless signal transmission module 72, which may be a Bluetooth0 radio. The power supply module 70 is configured to retain a battery and includes a PCB 74 to monitor charge, discharge rate and other variables.
In another embodiment, the power supply module 70 is a radio frequency wireless charging unit. The external acoustic sensor system 14 communicates wirelessly with the multi-sensor fusion module 50 and is housed in a housing 76 which is separate to the multi-sensor fusion module housing 78.

Date Recue/Date Received 2021-09-08 In an alternative embodiment of the systems of Figures 2, 3 and 4, the internal acoustic sensor systems 16, 18 may be hard wired to the multi-sensor fusion module 50 and therefore do not include the wireless radio 34 or the power supply module 36.
In all the above embodiments there may be more than two internal acoustic sensor systems and therefore, correspondingly more than two acoustic signal processing modules 38. The acoustic signal processing modules 38 include a PCB, a power supply module and a wired or wireless communications module, which may be a Bluetooth radio.
In a preferred embodiment, as shown in Figure 5, an anti-vibration control system, generally referred to as 100 is for an industrial machine. The anti-vibration control system 100 includes a signal processing and control module 110 that communicates with a control panel 112 of the industrial machine and three acoustic sensor systems, an external acoustic sensor system 114 and two internal acoustic sensor systems 116, 118.
The external acoustic sensor system114 is affixed to an exterior surface of the industrial machine and is configured to sense ambient noise. The two internal acoustic sensory systems 116, 118 are housed within the work envelope and are configured to sense acoustic signals associated with processing. They are located on opposite sides of the work envelope to one another. The industrial machine may be a milling machine, a cutting machine or a turning machine and the tool may be a cutting tool or a rotating tool.
The acoustic sensor systems 114, 116, 118 each include a printed circuit board (PCB) 130, a microelectromechanical acoustic sensor 132, and an acoustic signal processing module 138. Each acoustic sensor system 114, 116, 118 is protected with an acoustically transparent but hydrophobic membrane such that an Ingress Protection Rating of 67 or greater is achieved, while not degrading the integrity of the acoustic signals. The internal acoustic sensor systems 116, 118 are each housed in a housing 142. The microelectromechanical acoustic sensors 132 are each in wired communication with an acoustic signal processing module 138 via the PCB 130. The external acoustic sensor system 114 is housed in a housing 148 on the exterior surface of the industrial machine.
It is in wired communication with the signal processing module 138. The signal processing and control module 110 is integral with a PCB 149 and is housed in the housing 148 on the exterior surface of the industrial machine. The signal processing and Date Recue/Date Received 2021-09-08 control module 110 communicates with each acoustic signal processing module 138 and with a computing unit 162, which includes the signal processing and control module 110.
In another preferred alternative embodiment, as shown in Figure 6, the acoustic sensor systems 114, 116, 118 each include a printed circuit board (PCB) 130 and a microelectromechanical acoustic sensor 132. The internal acoustic sensor systems 116, 118 each further include a wireless radio 134, which may be a Bluetooth0 radio, a power supply module 136 and an acoustic signal processing module 138. In one embodiment the power supply module 136 is configured to retain a battery and includes a PCB 140 to monitor charge, discharge rate and other variables. In another embodiment, the power supply module 136 is a radio frequency wireless charging unit. Each acoustic sensor system 114, 116, 118 is protected with an acoustically transparent but hydrophobic membrane such that an Ingress Protection Rating of 67 or greater is achieved, while not degrading the integrity of the acoustic signals. The internal acoustic sensor systems 116, 118 are each housed in a housing 142. The microelectromechanical acoustic sensors 132 of all the acoustic sensor systems 114, 116, 118 are each in wireless or wired communication with an acoustic signal processing module 138 via the PCB 130.
The external acoustic sensor system 114 is housed in a housing 148 on the exterior surface of the industrial machine. It is in wired communication with a signal reception module 158, which may be a Bluetooth0 radio. The signal processing and control module 110 is integral with a PCB 149 and is housed in the housing 148 on the exterior surface of the industrial machine. The signal processing module and control 110 communicates with each acoustic signal processing module 138 via the Bluetooth communication link (134 and 158). Both the signal processing and control module 110 and the signal reception module 158 are part of the computing unit 162.The signal processing module and control 110 is in wired communication with the control panel 12.
In all embodiments, the first internal acoustic sensor system 16/116 is symmetrically opposite the second internal acoustic sensor system 18/118.
As noted above, the external acoustic sensor system 14/114 is for detecting and measuring ambient noise in the environment. This is subtracted from the acoustic signals from the internal acoustic sensor system 16/116, 18/118 acoustic signals. The internal Date Recue/Date Received 2021-09-08 acoustic sensor systems 16/116, 18/118 detect and measure acoustic signals associated with processing and environmental acoustic signals within the work envelope 22. These are also subtracted from the acoustic signals associated with processing and include acoustic signals resulting from, for example, but not limited to coolant, spindle frequency, tool passing frequency, tooth passing frequency and swan. The acoustic signals associated with processing include spikes which are indicative of vibration (chatter). The redundancy in internal acoustic sensors 16/116, 18/118 allows for data sharing which will allow additional digital signal processing (DSP) to occur, for example, but not limited to overlap-add, overlap-subtract, or other methods to minimize noise, and maximize desirable signal extraction around the work envelop. Results from this will isolate actualized instances of undesirable features within a signal, while simultaneously isolating falsified instances of undesirable excitation. Deploying this iterative check maximizes robustness and promotes processing optimization. The positioning of the first internal acoustic sensor system 16 and the second internal acoustic sensor system maximizes collection and transmission of undesirable acoustic signals associated with processing and minimize collection and transmission of environmental acoustic signals in the work envelope 22. The mechanical structure of the acoustic sensor systems 14/114, 16/116, 18/118 ensures that no feature has a resonance between the frequency bandwidth range specified (dynamic stability) and is affixed by any means to cause unnecessary contamination of the acoustic signal through self-excitation.
The computing unit 62 includes the signal processing and control module 10/110 which includes signal processing algorithm (SPA), a generalized learning algorithm (GLA) and a self-learning algorithm (SLA). The SPA is configured to detect features of the acoustic signals that are indicative of chatter and other undesirable process related sounds. The SPA reads the signal transmitted by the acoustic sensors 14/114, 16/116, 18/118 or from the multisensory fusion module 50 effectively detecting spikes in the discrete Fourier Transform of the time-domain signal. Upon detection, the SPA instructs the machine 10 to eliminate this vibration ("chatter") or other undesirable signal features by a method of discrete spindle speed tuning, discrete spindle depth tuning, discrete spindle width tuning, and/or continuous spindle speed variation. The results are saved in a process stability database.

Date Recue/Date Received 2021-09-08 The GLA was developed to establish a learned database from the signals received (experienced) from the multi-sensor fusion module 50 or the acoustic sensors 14/114, 16/116, 18/118 and the decisions made (use of data) by the signal processing and control module 10/110 by correlating inputs in terms of machine operating parameters with outputs in terms of acoustic data forming a learned stability database for future exploitation. In each different embodiment the GLA deployed one of the following supervised algorithms: (a) Neural Networks; (b) Naïve Bayes; (c) Linear Regression; (d) Logistic Regression; (e) Support Vector Machine (SVM); (f) K-nearest Neighbor;
and (g) Random Forest.
The SLA expands on the learned database, by automatically expanding a self-learned stability database. Based on the learned stability database developed by the GLA, the SLA will capitalize on the information provided to expand on the database. In each different embodiment the SLA deployed one of the following unsupervised algorithms: (a) Clustering; (b) Exclusive and Overlapping Clustering; (c) Hierarchical Clustering; (d) Probabilistic Clustering; (e) Association Rules; (f) A priori Algorithms; (g) Dimensionality Reduction; (h) Principal Component Analysis; (i) Singular Value Decomposition;
and (j) Autoencoders.
To develop the SPA the following processing information was needed: a stability lobe diagram for the machine; tool specifications; machine specifications; and environmental noise baseline.
To develop the stability lobe diagram for orthogonal turning, the following was required:
dynamic parameters of the tool, including but not limited to natural frequency, damping ratio and stiffness as described by the frequency response function using the industry standard hammer test where n=10; and cutting force coefficients as measured with a dynamometer. For two degrees of freedom milling the start and exit angles were also needed. Once the stability lobe diagram was generated the following steps were taken by the SPA in order to detect vibration (using the first and the second embodiments as examples, but applicable to all embodiments):
1. The machine was operated and time domain acoustic signals were sent to the computing device as described above.
Date Recue/Date Received 2021-09-08 2. The time-domain acoustic signals were transformed using the Fast Fourier Transform (FFT) to generate an FFT spectrum.
3. The FFT spectrum was searched for frequencies and magnitudes that were not spindle frequencies or magnitudes, tool passing frequencies or magnitudes, tooth passing frequencies or magnitudes or harmonics thereof in order to detect and identify the chatter frequencies and/or magnitudes.
4. If the filtered FFT magnitude was greater than largest unfiltered FFT
magnitude the process was unstable and chatter magnitudes were detected. If the filtered FFT

magnitude was less than or equal to the largest unfiltered FFT magnitude the process was stable. Similarly, if the filtered FFT frequency was greater than largest unfiltered FFT
frequency the process was unstable and chatter frequencies were detected. If the filtered FFT frequency was less than or equal to the largest unfiltered FFT frequency the process was stable.

5. The chatter frequency and magnitude were isolated from the FFT spectrum and were displayed.

6. The machine feed was stopped and the stability lobe diagram was used to determine which of discrete spindle speed tuning, discrete spindle depth tuning, discrete spindle width tuning, and/or continuous spindle speed variation was needed to reduce or eliminate the chatter.

7. The data were sent to the process stability database for use by the SLA
and/or the GLA.

8. The signal processing and control module 10 communicated wirelessly with the control panel 12 and the control panel, under control of the signal processing and control module 10, automatically employed one or more of the following:
A) Modified the spindle speed to be at the average bandwidth at lowest lobe order while remaining within the upper limit of the workpiece, machine and cutting tool boundaries. If spindle speed was outside of the upper limit of the workpiece, machine and cutting tool boundaries, the spindle speed was lowered to the average bandwidth at iteratively higher Date Recue/Date Received 2021-09-08 lobe orders, remaining within the lower limit of the workpiece, machine and cutting tool boundaries. If neither was effective at reducing or eliminating chatter, the continuous spindle speed variation sub-routine was employed.
In situations where that was not effective at reducing or eliminating vibration, the depth of cut was automatically modified.
If neither of these were effective, both the depth of cut and spindle speed were automatically modified.
B) Modified the depth of cut selection method by automatically decreasing the depth of cut remaining at the current spindle speed to reach the stable-unstable intersection of the stability lobe diagram and override the feed rate proportionally to maintain spindle speed.
C) Modified the spindle speed and the depth of cut selection method by automatically increasing the spindle speed to be at the average bandwidth at lowest lobe order while remaining within the upper limit of the workpiece, machine and cutting tool boundaries and automatically increase the current depth of cut to reach the stable-unstable intersection of the stability lobe diagram. If spindle speed was outside of the upper limit of the workpiece, machine and cutting tool boundaries, the spindle speed was lowered to the average bandwidth at iteratively higher lobe orders, remaining within the lower limit of the workpiece, machine and cutting tool boundaries and automatically increase depth of cut. If increasing and decreasing the spindle speed was not effective, the depth of cut was automatically decreased to reach the stable-unstable intersection of the stability lobe diagram. The feed rate was over-ridden as needed.
D) Continuously modified the spindle speed by first determining the optimal amplitude and limit amplitude ratio by a predetermined percentage, then if the optical amplitude was larger than the amplitude ratio, the optimal amplitude was set as the amplitude ratio. After that optimal frequency was calculated at mean spindle speed. Pmax was set as a percentage of maximum spindle power or was calculated with the spindle moment of inertia. Finally, if the optimal frequency was calculated to be larger than the spindle drive bandwidth, it was set as spindle drive bandwidth.
The foregoing allows for autonomous, non-interfering dynamic monitoring and correcting to reduce or eliminate chatter.

Date Recue/Date Received 2021-09-08 While example embodiments have been described in connection with what is presently considered to be an example of a possible most practical and/or suitable embodiment, it is to be understood that the descriptions are not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the example embodiment.
Those skilled in the art will recognize or be able to ascertain using no more than routine experimentation, many equivalents to the specific example embodiments specifically described herein. Such equivalents are intended to be encompassed in the scope of the claims, if appended hereto or subsequently filed.

Date Recue/Date Received 2021-09-08

Claims (42)

1. An anti-vibration control system for use with an industrial machine with a rotating tool, an interior, an exterior and a control panel, the anti-vibration control system comprising: an exterior acoustic sensor system which includes an acoustic sensor and an exterior acoustic signal processing module, which is in an external printed circuit board (PCB) and is in communication with the acoustic sensor; an exterior housing that is configured for placement on the exterior of the industrial machine and houses the exterior acoustic sensor system; a first interior acoustic sensor system which includes a first interior acoustic sensor and a first acoustic signal processing module which is in communication with the first interior acoustic sensor;
a second interior acoustic sensor system which includes a second interior acoustic sensor and a second acoustic signal processing module which is in communication with the second interior acoustic sensor; a first interior housing that is configured for placement in the interior of the industrial machine and houses the first interior acoustic sensor system; a second interior housing that is configured for placement in the interior of the industrial machine and houses the second interior acoustic sensor system; and a signal processing and control module which is configured to receive and process acoustic signals from each of the acoustic signal processing modules and send instructions to the control panel of the industrial machine.

2. The anti-vibration control system of claim 1 wherein the signal processing and control module is configured to process acoustic signals from each acoustic sensor system to minimize acoustic signals arising from ambient noise and maximize acoustic signals arising from machine operations.

3. The anti-vibration control system of claim 2, further comprising a computing unit which includes the signal processing and control module.

4. The anti-vibration control system of claim 3, wherein the signal processing and control module is configured to detect features of the acoustic signals that are indicative of chatter.

5. The anti-vibration control system of claim 4, wherein the signal processing and control module is configured to correlate operating conditions of the industrial Date Recue/Date Received 2021-09-08 machine with features of the acoustic signals that are indicative of chatter and to develop a process stability database.

6. The anti-vibration control system of claim 5, wherein the signal processing and control module is configured to learn from the process stability database to provide a learned stability database.

7. The anti-vibration control system of claim 6, wherein the signal processing and control module is configured to reduce or eliminate chatter using the learned stability database.

8. A combination comprising an anti-vibration control system and an industrial machine with a rotating tool, the industrial machine including an exterior, an interior and a control panel, the anti-vibration control system including: an exterior acoustic sensor system which includes an acoustic sensor and an exterior acoustic signal processing module, which is in an external printed circuit board (PCB) and is in communication with the acoustic sensor; an exterior housing that is on the exterior of the industrial machine and houses the exterior acoustic sensor system; a first interior acoustic sensor system which includes a first interior acoustic sensor and a first acoustic signal processing module in communication with the first interior acoustic sensor; a second interior acoustic sensor system which includes a second interior acoustic sensor and a second acoustic signal processing module which is in communication with the second interior acoustic sensor; a first interior housing that is in the interior of the industrial machine and houses the first interior acoustic sensor system; a second interior housing that is in the interior of the industrial machine and houses the second interior acoustic sensor system; and a signal processing and control module which is configured to receive and process acoustic signals from each of the acoustic signal processing modules and send instructions to the control panel of the industrial machine.

9. The combination of claim 8, wherein the acoustic signal processing modules of each of the first interior acoustic sensor system and the second interior acoustic sensor system are in wireless communication with the signal processing and control module.
Date Recue/Date Received 2021-09-08

10. The combination of claim 8 or 9 wherein the exterior acoustic sensor system, the first interior acoustic sensor system and the second interior acoustic sensor system each include a pair of acoustic sensors.

11. The combination of any one of claims 8 to 10, wherein the acoustic sensors are m icroelectromechanical acoustic sensors.

12.A method of reducing or eliminating chatter in an industrial machine with a rotating tool, the method comprising:
-selecting an anti-vibration control system, the anti-vibration control system including: an exterior acoustic sensor system which includes an exterior acoustic sensor and an exterior signal processing module; an exterior housing that houses the exterior acoustic sensor system; a first interior acoustic sensor system, including a first interior acoustic sensor and a first acoustic signal processing module; a second interior acoustic sensor system, including a second interior acoustic sensor, and a second acoustic signal processing module; a first interior housing that houses the first interior acoustic sensor system; a second interior housing that houses the second interior acoustic sensor system; and a signal processing and control module which is in wired or wireless communication with the exterior, the first interior and the second interior signal processing modules;
-attaching the exterior housing to an exterior surface of the industrial machine and attaching the first and the second interior housing to an interior surface of the industrial machine;
-processing a workpiece with the industrial machine and concomitantly, the anti-vibration control system autonomously: sensing acoustic signals; processing the acoustic signals; and sending instructions to the control panel of the industrial machine to modify its operating parameters, thereby reducing or eliminating chatter.

13. The method of claim 12, wherein the instructions are to modify the speed of the spindle of the industrial machine.

14. The method of claim 12, wherein the instructions are to modify the depth of cut.

15. The method of claim 12, wherein the instructions are to modify both the speed of the spindle and the depth of the cut.

Date Recue/Date Received 2021-09-08

16. The method of any one of claims 12 to 15, wherein the multi-sensor fusion module processes acoustic signals from each acoustic sensor system to minimize acoustic signals arising from ambient noise and maximize acoustic signals arising from processing a workpiece.

17. The method of claim 16, wherein the signal processing modules each transmit a signal to the signal processing and control module.

18. The method of claim 17, wherein the signal processing and control module detects features of the signals that are indicative of chatter.

19. The method of claims 17 or 18, wherein the signal processing and control module correlates operating conditions of the industrial machine with features of the signals that are indicative of chatter and develops a process stability database.

20. The method of claim 19, wherein the signal processing and control module learns from the process stability database to provide a learned stability database.

21. The method of claim 20, wherein the signal processing and control module reduces or eliminates chatter using the learned stability database to determine instructions for the control panel of the industrial machine.

22. An anti-vibration control system for use with an industrial machine with a rotating tool, an interior, an exterior and a control panel, the anti-vibration control system comprising: an exterior acoustic sensor system which includes an acoustic sensor and an external printed circuit board (PCB); a multi-sensor fusion module which includes the external PCB and a wireless radio; an exterior housing that is configured for placement on the exterior of the industrial machine and houses the exterior acoustic sensor system and the multi-sensor fusion module; a first interior acoustic sensor system and a second interior acoustic sensor system, each including an acoustic sensor, an internal PCB, a power supply module and an acoustic signal processing module, the acoustic signal processing module in wired or wireless communication with the multi-sensor fusion module; a first interior housing that is configured for placement in the interior of the industrial machine and houses the first interior acoustic sensor system; a second interior housing that is configured for placement in the interior of the industrial machine and houses the second interior acoustic sensor system; and a signal processing and control Date Recue/Date Received 2021-09-08 module which includes a wireless radio and is configured to receive and process acoustic signals from the multi-sensor fusion module and send instructions to the control panel of the industrial machine.

23. The anti-vibration control system of claim 22 wherein the multi-sensor fusion module is configured to process acoustic signals from each acoustic sensor system to minimize acoustic signals arising from ambient noise and maximize acoustic signals arising from machine operations.

24. The anti-vibration control system of claim 23, wherein the multi-sensor fusion module is configured to transmit a summary signal to the signal processing module.

25. The anti-vibration control system of claim 24, wherein the signal processing and control module is configured to detect features of the summary signal that are indicative of chatter.

26. The anti-vibration control system of claim 25, wherein the signal processing and control module is configured to correlate operating conditions of the industrial machine with features of the summary signal that are indicative of chatter and to develop a process stability database.

27. The anti-vibration control system of claim 26, wherein the signal processing and control module is configured to learn from the process stability database to provide a learned stability database.

28. The anti-vibration control system of claim 27, wherein the signal processing and control module is configured to reduce or eliminate chatter using the learned stability database.

29.A combination comprising an anti-vibration control system and an industrial machine with a rotating tool, the industrial machine including an exterior, an interior and a control panel, the anti-vibration control system including an exterior acoustic sensor system which includes an acoustic sensor and an external printed circuit board (PCB); a multi-sensor fusion module which includes the external PCB and a wireless radio; an exterior housing that is located on the exterior of the industrial machine and houses the exterior acoustic sensor system and the multi-sensor fusion module; a first interior acoustic sensor system and a second interior acoustic Date Recue/Date Received 2021-09-08 sensor system, each including an acoustic sensor, an internal PCB, a power supply module and an acoustic signal processing module, the acoustic signal processing module in wired or wireless communication with the multi-sensor fusion module; a first interior housing that is located in the interior of the industrial machine and houses the first interior acoustic sensor system; a second interior housing that is located in the interior of the industrial machine and houses the second interior acoustic sensor system; and a signal processing and control module which includes a wireless radio and is configured to receive and process acoustic signals from the multi-sensor fusion module and send instructions to the control panel of the industrial machine.

30. The combination of claim 29, wherein the acoustic signal processing modules of each of the first interior acoustic sensor system and the second interior acoustic sensor system are in wireless communication with the multi-sensor fusion module.

31. The combination of claim 29 or 30 wherein the exterior acoustic sensor system, the first interior acoustic sensor system and the second interior acoustic sensor system each include a pair of acoustic sensors.

32. The combination of any one of claims 29 to 31, wherein the acoustic sensors are m icroelectromechanical acoustic sensors.

33.A method of reducing or eliminating chatter in an industrial machine with a rotating tool, the method comprising:
-selecting an anti-vibration control system, the anti-vibration control system including: an exterior acoustic sensor system which includes an acoustic sensor;
a multi-sensor fusion module; an exterior housing that houses the exterior acoustic sensor system and the multi-sensor fusion module; a first interior acoustic sensor system and a second interior acoustic sensor system, each including an acoustic sensor, and an acoustic signal processing module, the acoustic signal processing module in wired or wireless communication with the multi-sensor fusion module;
a first interior housing that houses the first interior acoustic sensor system;
a second interior housing that houses the second interior acoustic sensor system; and a signal processing and control module which includes a wireless radio;

Date Recue/Date Received 2021-09-08 -attaching the exterior housing to an exterior surface of the industrial machine and attaching the first and the second interior housing to an interior surface of the industrial machine;
-processing a workpiece with the industrial machine and concomitantly, the anti-vibration control system autonomously: sensing acoustic signals; processing the acoustic signals; and sending instructions to the control panel of the industrial machine to modify its operating parameters, thereby reducing or eliminating chatter.

34. The method of claim 33, wherein the instructions are to modify the speed of the spindle of the industrial machine.

35. The method of claim 34, wherein the instructions are to modify the depth of cut.

36. The method of claim 34, wherein the instructions are to modify both the speed of the spindle and the depth of the cut.

37. The method of any one of claims 33 to 36, wherein the multi-sensor fusion module processes acoustic signals from each acoustic sensor system to minimize acoustic signals arising from ambient noise and maximize acoustic signals arising from processing a workpiece.

38. The method of claim 37, wherein the multi-sensor fusion module transmits a summary signal to the signal processing module.

39. The method of claim 38, wherein the signal processing and control module detects features of the summary signal that are indicative of chatter.

40. The method of claims 38 or 39, wherein the signal processing and control module correlates operating conditions of the industrial machine with features of the summary signal that are indicative of chatter and develops a process stability database.

41. The method of claim 40, wherein the signal processing and control module learns from the process stability database to provide a learned stability database.

42. The method of claim 41, wherein the signal processing and control module reduces or eliminates chatter using the learned stability database to determine instructions for the control panel of the industrial machine.
Date Recue/Date Received 2021-09-08