Abstract: A spindle apparatus comprises a main shaft mounted for rotary movement, a rotating device for rotating the main shaft about an axis, a vibration device for vibrating the main shaft, a detecting device for detecting a displacement of the main shaft when the main shaft is vibrated by the vibration device and providing an output signal indicative of the displacement of the main shaft, a calculating device for calculating an allowable revolution speed of the main shaft on the basis of the output signal of the detecting device, and a drive source for driving the rotating device to rotate the main shaft within a speed range which does not exceed the allowable revolution speed. When an end of the main shaft is vibrated by the vibration device, a displacement of the vibrated main shaft is detected by the detecting device which provides an output signal indicative of the detected displacement.

Abstract: A portable three axis scanner is usable to inspect a gas turbine engine spool in situ upon removing a fan module from the engine. The scanner includes a drive assembly mountable to a forward end of the spool, and a support assembly mountable to an aft end of the spool. A support beam extends between the drive and support assemblies, and a carriage assembly is mounted thereon. The carriage assembly includes a probe support for mounting a removable scanner probe for inspecting the inside of the spool by ultrasonic or eddy current inspection. The drive assembly includes means for axially translating the carriage assembly, means for rotating the carriage assembly, and means for radially translating the probe support and probe thereon so that the probe has three-axis movement including axial, circumferential, and radial, respectively, for being selectively positioned inside the spool between the forward and aft ends thereof for inspecting the spool.

Abstract: An on-line ultrasonic sensor for monitoring and sensing failure in a cutting tool insert. The preferred embodiment of the sensor includes a piezoelectric film of aluminum nitride (AlN) deposited onto a tool insert or tool insert seat with the AlN film electrically connected to a signal generator and detection circuitry. A voltage pulse is applied to the AlN film to generate ultrasonic signal pulses in the AlN film which are transmitted through a tool insert to the vicinity of the cutting edge of the tool insert during use. Back-reflected ultrasonic signals from the edge of the tool insert induce a voltage signal in the piezoelectric film which is analysed and compared to signals characteristic of undamaged tool inserts. Temperature increases, wear and various types of tool failure can be readily detected during use of the insert with the sensor.

Abstract: The encapsulated transducer (10) includes an injection molded encapsulation (20) having a front end (22) and a back end (24). The encapsulation (20) ensconces a sensing element (40) proximate the front end (22) and a portion of a cable (60) which extends from the back end (24). The sensing element or coil (40) is electrically and mechanically connected to the cable (60) by a pair of suitably sized front and rear ferrules (80), (90) secured to a center and coaxial conductor (66), (70) of the associated cable (60) thereby forming a coil and cable assembly (110). At least the rear ferrule (90) includes a shoulder (100) for firmly anchoring the coil and cable assembly (110) within the encapsulation (20). In addition an injection molding process provides the durable encapsulation (20) which bonds with a dielectric (68) of the cable (60) and symmetrically locks the coil and cable assembly (110) therein.

Abstract: A passive blade vibration monitor sensor for determining an arrival time of a blade of a combustion turbine during operation, the sensor includes an optical lens which receives infrared radiation generated by the blade of the turbine and generates a sensor signal from the received infrared radiation, the sensor signal indicating an arrival time of the blade of the combustion turbine. Target material having an emissivity lower than the emissivity of the blade may be placed on the blade to enhance sensor sensitivity especially in shrouded blade environments.

Abstract: This invention provides a device for capacitively measuring the distance to an object, which comprises an electrode that will couple capacitively with the object, a shield that surrounds the electrode and is electrically isolated from the electrode by means of insulation, and a layer of insulation that surrounds the shield, wherein the insulation between the electrode and the shield, and the insulation that surrounds the shield, are formed by deposition.This invention further provides a method for measuring the distance to a solid object, which comprises forming an electrode that will capacitively couple with the object, depositing a layer of insulation over at least part of the electrode so that the insulation surrounds the electrode, depositing a layer of metal over the insulation to form a shield, and depositing a second layer of insulation over the shield.

Abstract: The present invention provides a system for detecting and removing resonance from crankshaft speed measurements comprising signal demodulation and deconvolution processing. According to the invention, a crankshaft speed sensor sends an appropriate signal corresponding to crankshaft speed to an engine controller. The input signal with resonance noise is subjected to a demodulation operation in N demodulation subsystems for resonance detection and identification. Also, the input signal with resonance noise is subjected to a deconvolution operation in N deconvolution subsystems for resonance noise removal. The demodulated signals are compared to a given set of criteria for selecting a desired signal subsystem. The desired demodulated signal subsystem is then used to screen the deconvolved signal so that only a matching deconvolved signal exits the system as the system output.

Abstract: A method of determining the rotational speed of a rotating shaft from machine vibration data. The vibration produced by the shaft is sensed to produce a test vibration signal at an unknown rotational speed of the shaft, which test vibrational signal is converted to a test frequency spectrum. A reference frequency spectrum, corresponding to a known rotational speed of the shaft, is provided, and a stretch factor is determined. The stretch factor provides optimum correlation between the test frequency spectrum and the reference frequency spectrum. The unknown speed of the rotating shaft is calculated using the known speed of the reference frequency spectrum and the stretch factor.

Abstract: In a first preferred embodiment a transmitting acoustic transducer mounted on the tool axis or spindle of a grinding tool affords a method for pre-contact recognition and control (touch-off) independent of tool grit, workpiece material, and all natural machining frequencies. The transmitting transducer such as a piezoelectric polymer or crystal generates a selected frequency of approximately 1-5 MHz. As the tool enters a lubricating plume surrounding the workpiece, the ultrasonic transmission couples through the fluid interface to the workpiece. A receiving transducer mounted on the optical workpiece gives a unequivocal and rapid detection of the transmission by a highly filtered(band pass) receiving transducer before the tool contacts the workpiece. In a second preferred embodiment, a photoacoustic laser excites a modulated frequency to the grinding tool and to the receiving transducer.

Abstract: A monitoring system for representing vibration conditions of a multiplicity of blades on a rotating disc in a turbomachine includes at least one sensor which is associated with the disc and which is connected to a pulse generator that delivers sensor pulses which respectively mark an instant at which a blade passes the sensor, a mark pick-up which always delivers a mark pulse when the disc is in a certain zero position, and an analysis device. The latter has an allocation module which takes account of the mark pulses and associates each sensor pulse with the blade which has caused it when passing a sensor. The allocation module calculates vibration data from the associated sensor pulses, which characterize the vibration conditions of the blade. A memory module has access to a working memory to which the vibration data are supplied and the memory module stores the vibration data in the working memory.

Abstract: A rotational-device test system and method is provided to classify a rotational device according to the type of drive sound thereof. A divider divides the time-series data of an amplitude of the drive sound of an HDD digitized in a converter at intervals of a predetermined time and generates a time-series data group for each frame. An analyzer converts each data item of the time-series data group to a power spectrum. A cycle arithmetic unit selects a maximum point whose self-correlation between a leading frame and each of frames other than the leading frame is maximum, as a candidate point for one cycle of the drive sound, and detects a point whose self-correlation is maximum and which has as a starting point the leading time-series data in the leading frame and the candidate point, and, based on the frame of the candidate point in the detected point whose self-correlation is maximum and on the leading frame, specifies the cycle of the drive sound.

Abstract: A system detects relative movement between an optical sensor unit and a set of finely spaced, parallel grid lines. Unlike prior optical line detection systems, each set of lines is applied to a surface of an object at an angle relative to movement between the optical sensor unit and the object. The system is particularly useful for monitoring rotating members, such as shafts, but is also useful with linearly moving members. In a preferred shaft monitoring application, a plurality of optical units are provided, with a plurality of corresponding sets of parallel lines at different angles on the shaft. Signal output phase differences between the optical units are compared to precisely determine movement of the shaft in seven directions of freedom, including rigid body displacement components along three translational and three rotational axes, and shaft twist.

Abstract: A system for real time identification of modes of oscillation includes a sensor, an observer, a controller and an actuator. The sensor senses a controlled system such as a combustor, and generates a signal indicative of the modes of oscillation in the controlled system. For example, these modes of oscillation can be combustion instabilities. The observer receives the signal from the sensor, and uses the signal to determine modal functions and frequencies of the modes of interest with a pair of integrals with changing time limits. The controller receives the modal functions and frequency for each mode of interest from the observer, and effects a gain and phase shift for each mode. Based on the modal functions, the frequency, the gain and the phase shift, the controller generates and outputs a control signal, that is supplied to the actuator. The actuator controls the modes of oscillation of the controlled system, based on the control signal.

Abstract: A method and apparatus for evaluating the vibration of a rotary body in a static or non-rotational state to determine a profile of critical speeds including profiles of critical speeds which exist beyond a rated revolution velocity of the rotary body. This invention comprises: a plurality of bearings for maintaining the rotary body in a non-rotating or static condition; a rotary vibrator for applying an exciting force which is rotated about a shaft to the rotary body; a vibration sensor for detecting the vibration of the rotary body; a vibration meter for measuring an output from the vibration sensor; and a vibration power source for supplying AC power to the rotary vibrator and for sweeping a frequency of the exciting force applied from the rotary vibrator to the rotary body from a low-frequency region to a high-frequency region.

Abstract: The encapsulated transducer (10) includes an injection molded encapsulation (20) having a front end (22) and a back end (24). The encapsulation (20) ensconces a sensing element (40) proximate the front end (22) and a portion of a cable (60) which extends from the back end (24). The sensing element or coil (40) is electrically and mechanically connected to the cable (60) by a pair of suitably sized front and rear ferrules (80), (90) secured to a center and coaxial conductor (66), (70) of the associated cable (60) thereby forming a coil and cable assembly (110). At least the rear ferrule (90) includes a shoulder (100) for firmly anchoring the coil and cable assembly (110) within the encapsulation (20). In addition an injection molding process provides the durable encapsulation (20) which bonds with a dielectric (68) of the cable (60) and symmetrically locks the coil and cable assembly (110) therein.

Abstract: A vibration sensing apparatus including an acceleration sensor 2 for outputting a sensing signal corresponding to a vibrating acceleration, a level discriminator 3 for generating an output when the output level of the signal from the acceleration sensor 2 exceeds a preset reference level, a display unit 4 for displaying the output of the level discriminator 3, a piezoelectric ceramic power generating unit 5 using piezoelectric ceramics for generating a charge when it is subjected to vibration, and a conversion unit 6 for converting the charge generated by the piezoelectric ceramic power generating unit 5 into DC power, the DC power being supplied to the level discriminator and to the display unit as power to be consumed by them.

Abstract: A method for analysing regularly recurring mechanical vibrations comprises the steps of plotting an amplitude/time spectrum associated with the vibrations, dividing the amplitude/time spectrum into time intervals shorter than the shortest time lapse between two consecutive excitations, subjecting those parts of the amplitude/time spectrum defined by each time interval to a Fourier transformation in order to obtain an amplitude/vibration-frequency interval spectrum associated with each time interval, and subjecting those amplitudes in each amplitude/vibration frequency interval spectrum associated with certain vibration frequencies to a Fourier transformation in order to obtain an excitation-frequency spectrum associated with the respective vibration frequency.

Abstract: The proposal is for a process and device making it possible to determine the condition of one or more machines (3) at several measuring points by means of a measuring head (MK) with measurement transducers (MW) which can be releasably fitted there and to supply to a computer the relevant measurement signal together with the characteristic data therefore obtained at the measuring point concerned. The invention lies in the special nature of the obtaining of the characteristic data.

Abstract: A method and device for processing encoder signals from turbomachines to produce frequency modulation signals representing fully isolated rotor vibrational resonances. Multi-sensor and multi-sideband group processing provides enhanced results. The method provides dramatically improved frequency resolution. Amplitude modulation and random noise effects are removed by a variety of artifact-free techniques. Signals then are completely separated into components for rotational vibration and translational vibration. Fully isolating rotational vibration unmasks previously undetectable signal components of diagnostic value. In cases of high background vibration, Wiener filtering removes the effects of exogenous vibration. By these various techniques, the present invention provides significantly enhanced diagnostic information regarding condition and performance in turbomachines.

Abstract: A method and apparatus are provided for monitoring the operating conditions of an electric generator by producing a signal representative of vibration amplitude in end turns of stator windings of the generator; producing a signal representative of an electrical load under which said generator is operating; comparing the vibration and load signals to store reference data representative of normal or abnormal operating conditions; and producing an output signal based on a comparison of the vibration and load signals with the stored reference data. The output signal is representative of the operational status of the generator.

Abstract: A vibration detecting and condition monitoring system for the press section, including felts, rollers and presses, employing a feature extracting circuit having a selectable plurality of Bessel type bandpass filters and an enveloping circuit to square the bandpassed signal output prior to FFT analysis of the signal. The system enables the enhancement and detection of highly impulsive signals in the frequency domain, that are indicative of defects in machinery operation.

Abstract: An in-use rolling element bearing monitoring system which uses a piezoelectric film transducer on either a bearing, bearing support structure, or on a separate washer in close proximity to a bearing for monitoring bearing performance. One embodiment provides a bearing monitoring system for detecting and predicting bearing failure. Another embodiment provides a system configured for detecting rotational speed of a rolling element bearing. Each embodiment of the invention entails maintaining a piezoelectric film transducer in contiguous pressure wave responsive communication with a bearing for detecting bearing performance, and provides the system in a compact configuration for in-use operation on a variety of machinery and vehicle components heretofore previously not compatible.

Abstract: A nondestructive inspection device and a method of monitoring a defective condition in a rotating member of a combustion turbine engine using a nondestructive inspection device is presented. The nondestructive inspection device includes a sensor for monitoring the rotating member and a holder assembly for positioning the sensor near the rotating member without disassembling the combustion turbine engine. The holder assembly is capable of interchangeably positioning either an ultrasound transducer or an eddy current sensor. Signals indicative of the monitored condition are recorded and compared to a signal representation generated from a reference standard having a known defect so that a defective condition can be ascertained. The location of a defective condition is ascertained by using a magnetic belt having a plurality of magnets wrapped around the rotating member and an additional sensor to detect the magnets as they rotate.

Abstract: In a sensor system with a wireless vibration or structure-borne noise sensor device (1), which makes direct use of the vibration energy of its electrodynamic or piezoelectric measuring unit (5) without other components to transmit the vibration energy via a primary coil (6) of a transformer-like pair of coils (6, 7) electrically connected to the measuring unit (5), to the secondary coil (7) of said pair (6, 7) which is located in a receiver (2) independent of the sensor device (1) and separated only by an air gap (8) which conducts the measured and transformed vibration or structure-borne noise measurement signal further, the sensor system is used to monitor the vibration, structure-borne noise and/or sound especially of defined material-removing tools in machine tools or to detect the noise of noise-generating structural units in testing machines or devices. The sensor device (1) is arranged on a traversing and/or rotary machine component (14), e.g.

Abstract: A method measures the rotational speed of an engine turbocharger. A microphone picks up sound generated by the rotation of the turbocharger and a microphone signal containing signal components is supplied. Low-frequency signal components are filtered out from the microphone signal generated by engine operation including noise from valves, fans and gas flows. An electronic bandpass filter is tuned to the remaining signal component having the highest amplitude in the filtered microphone signal and the frequency of the remaining signal component having the highest amplitude is determined. With a knowledge of the turbocharger geometry, the value of the frequency of the remaining signal component having the highest amplitude is converted to the rotational speed of the turbocharger.

Abstract: An apparatus in which ultrasonic vibrations or acoustic emissions are detected includes a rotating shaft 21 having a dressing wheel 31 mounted on one end, and a detection liquid supply unit 41 disposed at the end face of the wheel and/or shaft so as to form a gap S therebetween and to supply detection liquid toward the rotational center of the wheel to form a detection liquid membrane in the gap. An AE sensor 43 is provided integrally with the detection liquid supply unit and detects the ultrasonic vibrations or acoustic emissions of the wheel and/or shaft through the detection liquid membrane formed in the gap.

Abstract: A method for analyzing the vibration of a tire uniformity machine having a number of rotating components uses the signals from load cells when the machine idle to output voltage signals that are then amplified and input into a computer as unfiltered, amplified voltage signals. The signals are converted into a power spectrum and selected groups of frequencies and their amplitude are compared with acceptable amplitudes for the frequencies generated by various rotating parts of the machine. When at least one of the amplitudes for different frequencies is greater than at least one of the acceptable amplitudes for the frequencies generating different rotating parts of the machine, the computer outputs an alarm signal.

Abstract: A method is provided for determining and for predicting the present and future condition of a machine having at least one rotative element. The method includes an initial step of storing in memory a predetermined logic routine and at least one predetermined key frequency of the at least one rotative element of the machine. The machine is operated in a predetermined operational state and, during operation, the mechanical motion of the at least one rotative element is sensed by at least one sensor. The sensed mechanical motion of the at least one rotative element is converted into a corresponding electrical signal, and the predetermined operational state of the machine is correlated with a corresponding electrical signal. The corresponding electrical signal is inputted into corresponding vibration data by utilizing the predetermined logic routine. Then, the corresponding vibration data is compared with the at least one predetermined key frequency to predict the present and future condition of the machine.

Abstract: A process and a computer implemented system for controlling an axial compressor through measurement of pressure fluctuations of the turbulent fluid layer in the region of the compressor housing in at least one stage of the compressor by means of at least one pressure sensing device sensitive to differential pressure fluctuations affecting the blades at the characteristic frequency of the stage. The process and computer implemented system use a characteristic peak which emerges under load in a smoothed frequency signal derived from a transform of the pressure measurement to achieve optimal efficiency while, at the same time, avoiding destructive surge and stall conditions in the compressor.

Abstract: A structure of a magnetostrictive shaft applicable to a magnetostriction-type torque sensor and a method for manufacturing the same can achieve a high torque sensitivity. A shaft parent material is made of a non-magnetic austenitic series metallic material (YHD50) and a magnetic thin film is made of a magnetostriction material such as Iron-Aluminum series alloy plasma spray coated on the whole outer peripheral surface of the shaft parent material. In a second embodiment, a mechanical working is carried out for the shaft material on the surface of which the magnetostriction material thin film is coated, the worked shaft material is heated under an inert gas atmosphere, and the heated shaft material is immersed into oil under the inert gas atmosphere to perform oil quenching.

Abstract: A tool monitoring system monitors the condition of an electrically powered tool performing a cyclical operation. The tool monitoring system operates generally in two modes: learning mode and monitor mode. In learning mode, the tool monitoring system gathers statistical data on the power consumption of tools of the selected tool type during learning cycles. A power threshold is generated based upon the statistical data. The tool monitoring system then counts the number of crossings by each of the learning cycles of the power threshold and generates statistical data regarding the number of crossings. Preferably, the mathematical operation of wavelet packet transform is used to calculate the power threshold. Feature wavelet packets of the power consumption signal of the tool are calculated. The power consumption signal is then reconstructed from the feature wavelet packets and used to determine the power threshold.

Abstract: A test unit is provided for operatively testing CV driveaxles. The test unit has a drive spindle connected to a motor, and a pivotable brake spindle connected to a brake. An axle under test is connected with spindle adaptors to the drive and brake spindles. During a test, the axle under test is rotated by the motor, the brake is engaged to load the axle, and the brake spindle is pivoted to flex at least the outboard CV joints. The test unit is easily adaptable for testing different axles by using spindle adaptors. An accelerometer on the bearing block of the brake spindle detects vibration generated by the axle under test.

Abstract: A gear noise evaluation system having a neuro-computer which is provided with sound pressure values from an FFT analyzer. At this time, an evaluator simultaneously presets an absolutely sensual evaluating value as a teacher signal from a control bench. The neuro-computer repeatedly performs a learning so that the pressure values may become the absolutely sensual evaluating value until the difference between the sound pressure value and the sensual evaluating value lies in a permissive error range thereby determining a function value.

Abstract: A signal device for turbo-engines which, by way of moving blades arranged on a rotor, when passing through a defined circumferential position of the housing, generates signals which are precise with respect to time. The device includes a probe which has fiber optical waveguides for emitting and receiving light. An illuminating beam is emitted which is focussed in the direction of the rotor. The probe is arranged on the housing at a distance with respect to free end faces of the moving blades. The probe emits the illuminating beam with an elliptical cross-section, through which the moving blades travel, in such a manner that, on each corresponding free end face, an elliptical illumination spot is imaged whose large axis is aligned essentially in parallel to the delivery-side or suction-side edges of the free end faces. The signals are generated from the light reflected by the free end faces.

Abstract: A cooling block is provided for mounting a transducer or other electronic component on a test object which typically becomes heated during use or testing. The cooling block receives a flow of cooling gas and distributes the gas to flow outwardly past the transducer and maintain the transducer in relatively stable, constant temperature conditions. The cooling block also functions as a heat absorber. The block may be mechanically or magnetically attached to the object under test.

Abstract: A portable, hand-held, battery-powered rotor balancing calculator has a data port, which includes a host communications port to down-load set-up data from, and upload collected data to a host computer. A rotation sensor communications port receives data from the rotation sensor, and a vibration sensor communications port receives data from vibration sensors. An angle sensor communications port receives data from an angle sensor, and the calculator determines how far and in what direction the rotor has been rotated. The calculator also employs a power supply, a processor, and an operator interface. There is also a memory for data storage, menus with check-off lists, and procedures, including raw data screening procedures and collected data analysis procedures. A display is provided which depicts gathered data in a graphical form which is easily reconfigured for rotor viewing orientation.

Abstract: A process and a computer implemented system for monitoring vibration in the blades of the rotor and stator of an axial compressor through measurement of pressure fluctuations of the dynamic pressure field in the region of the compressor housing in at least one stage of the compressor by means of at least one pressure sensing device sensitive to differential pressure fluctations affecting the blades at the characteristic frequency of the stage. The process and computer implemented system also assist in the control of the compressor by forwarding a status respecting rotor and stator mechanical vibration to the control unit.

Abstract: The present invention relates to a process for the early detection of a crack in a rotating shaft, particularly in a shaft of a turbo generator used in a power plant. Signals that represent flexural vibrations of the shaft are measured--as a function of the rotational angle, continuously or at time intervals by means of vibration sensors in at least two radial, preferably perpendicular, directions with respect to each other. These signals are transmitted to a signal processor which uses the signals to ascertain the harmonic vibration components with single and/or double and/or triple rotational frequencies and then the processor forms single and/or double and/or triple rotational-frequent vibration orbits by means of a vectorial combination of these vibration components.

Abstract: An improved apparatus and method for determining the existence and severity of a crack in a shaft system is provided. The apparatus includes means for mounting multiple vibration responsive output transducers around an outer circumference of the shaft system, allowing simultaneous measurements of vibrational response of the shaft system when multiple vibration responsive output transducers are mounted to the mounting means. In a first approach, the mounting means comprises a collar having two connected arcuate members, with drilled milled and tapped apertures for mounting radial input and output transducers. Torsional input and output transducers may also be mounted tangentially on the collar in drilled milled and tapped heads of bolts used to connect the two arcuate members.

Abstract: In chatter monitoring of twin drives of roll stands, vibrations of an upper drive and a lower drive are detected and monitored to determine whether a predetermined amplitude has been exceeded. If the amplitude has been exceeded, a chatter detection signal is generated. In order to prevent the chatter detection signal from being generated erroneously due to an operational pass vibrations, the frequencies of the vibrations of the upper drive and the lower drive are monitored for identity; when the frequencies are identical, the chatter detection signal is suppressed.

Abstract: A process and a device for the optical measurement of vibrations of rotating turbine blades moving with a specified speed of rotation. In one embodiment, the process comprises the steps of generating three reference signals in response to the detection, by an optical detector, of the passing of a marking made on the hub of a turbine wheel; detecting measurement signals, by another optical detector, in response to the passing of another marking made on at least one of the parts of a turbine blade, the blade undergoing oscillation; determining the time offsets existing between each of the reference signals and each of the measurement signals, these offsets being, in the absence of oscillations of the blade, zero or equal to specified constant values; and calculating the amplitude, frequency and phase components of blade vibration from the various offsets recorded.

Abstract: The present invention provides a method and system for analyzing signals from rotating machines containing rotating components that slip and, thereby, to detect faults in those components. The signals are processed by a series of steps to generate coherently averaged spectra and derived features that indicate defects in, or certain other features of, machine components that slip or rotate asynchronously.

Abstract: Bearing assembly including at least one proximity probe for monitoring the relative vibration of a rotating shaft contained therein. The bearing assembly includes a bearing housing surrounding and supporting a cylindrical shell. The cylindrical shell defines a shaft bore for receiving a rotating shaft. At least one proximity probe is embedded in the cylindrical shell for monitoring the shaft vibration. A second proximity probe may be added to enable monitoring radial shaft position. The proximity probes are connected to an instrument or instruments for displaying a signal received from the probes for allowing a user to determine shaft vibration or position.

Abstract: A cutting apparatus for finishing a surface of a substrate of a photoreceptor drum of an image forming apparatus estimates a finish state of the surface on real time with the finishing. The cutting apparatus has a detector to detect a cutting force to a cutting tool from the surface in finishing, a memory to store a cutting force pattern to distinguish the finish state of the surface, comparator means to compare the detected cutting force with the stored cutting force pattern and judging means to judge the finish state of the surface along with the progress of the cutting process.

Abstract: The present invention is a method and system for accurately analyzing shaft encoder signals from rotating machines. The invention reduces noise and other interferences in the encoder signals by novel means that yield an unprecedented power for extracting useful information. Signal distortion due to variation in the rotation rate of the machinery and due to FFT leakage are eliminated by acquiring digital values of the encoder signals at a set of discrete times that are determined by the properly averaged rotation rate of the shaft and requiring a fixed integer number of these discrete times per rotation of the shaft. Amplitude modulation is eliminated by proper spectral combination of left and right sidebands of the main encoder signal. Additive noise is removed by multiplying sidebands and averaging the results over a number of data records.

Abstract: To improve the coupling adjustment workability and precision of a rotor, irrespective of change in bearing characteristics due to an increase of rotational speed, the apparatus detects angular frequencies (.omega.) and reference mark positions (.theta.) of the rotor; detects vibration displacements (r) of the rotor; analyzes vibration vector components (.omega.), (r) and (.theta.) of rotation synchronizing vibrations; extracts a specific angular frequency (.omega..sub.1) at which a higher harmonic vibration frequency (.omega..sub.R) matches a natural frequency of the rotor, and various rotation synchronizing vibration vector components at (.omega..sub.1), at (.omega..sub.R) and (.omega..sub.2 to .omega..sub.i), respectively; estimates static vibration vector components (r.sub.0, .theta..sub.0) at zero angular frequency (.omega..sub.0) on the basis of rotation synchronizing vibration vector components (r.sub.T, .theta..sub.T) at (.omega..sub.1 to .omega..sub.

Abstract: A method of controlling the clearance angle of a veneer lathe knife in a veneer lathe having a knife holder beam rotatably mounted on a knife carrier. The beam's vibration frequency is continuously measured and compared with a stored representation of a vibration frequency range (about 50-200 Hz.) characteristic of disruption of the veneer peeling operation. If the comparison reveals that the measured vibration frequency is within the characteristic disruptive range, the beam is rotatably adjusted until the comparison reveals that the measured vibration frequency no longer lies within the disruptive range. Usually, the adjustment accelerates lowering of the beam in order to make the knife clearance angle less positive.

Abstract: A protrusion sensor according to the present invention comprises a protrusion sensing head, a suspension spring having a front end portion fixedly mounting the protrusion sensing head and a rear end portion fixedly secured to one surface of a support arm, a carriage for supporting the support arm and a vibration sensor of piezo-electric ceramics fixedly mounted on the other surface of the support arm. A protrusion is detected by the collision of the protrusion sensing head flying by air flow on a surface of a rotary disc caused by rotation thereof with a protrusion.

Abstract: Engine misfire is detected in a reciprocating internal combustion engine having an engine cycle frequency in the frequency domain from crankshaft angular velocity. Crankshaft angular position is sensed to develop an electrical signal which is a function of the crankshaft angular velocity. The electrical signal contains data which is sampled. The sampled data is transformed to an equivalent frequency domain spectrum including frequency components of the engine cycle frequency and harmonics thereof. A statistical decision algorithm is applied to the magnitudes of the frequency components to distinguish between a true misfire and normal cyclic variability which characterizes the combustion process. In one embodiment, the misfired cylinder is identified based on the phase of the frequency component at the engine cycle frequency. In another embodiment, the identity of the misfired cylinder is determined by shifting the sampled data prior to transforming the data.

Abstract: An apparatus for detecting contact between a contact detection member and a rotating body such as a grinding wheel rotably carried on a wheel head which is movable toward the contact detection member in a grinding machine for example. The apparatus comprises an AE sensor, a rectangular pulse generator, a sampling circuit and a processing device such as a microcomputer. The AE sensor generates an electric signal in response to vibration of the contact detection member. The rectangular pulse generator outputs a rectangular pulse whose duration corresponds to that of vibration. The sampling circuit delivers to the processing device an output indicating the duration of the rectangular pulse. The processing device processes the output delivered thereto so as to decide the occurrence of an actual contact between the rotating body and the contact detection member.