WO2001031350A1 - Systeme de commande destine a un systeme de test de mode de defaillance - Google Patents

Systeme de commande destine a un systeme de test de mode de defaillance Download PDF

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Publication number
WO2001031350A1
WO2001031350A1 PCT/US2000/029507 US0029507W WO0131350A1 WO 2001031350 A1 WO2001031350 A1 WO 2001031350A1 US 0029507 W US0029507 W US 0029507W WO 0131350 A1 WO0131350 A1 WO 0131350A1
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WO
WIPO (PCT)
Prior art keywords
pressure
frequency
frequency condition
slope
system response
Prior art date
Application number
PCT/US2000/029507
Other languages
English (en)
Inventor
Alexander J. Porter
Mark Allen Smith
Original Assignee
Entela, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Entela, Inc. filed Critical Entela, Inc.
Priority to AU12332/01A priority Critical patent/AU1233201A/en
Publication of WO2001031350A1 publication Critical patent/WO2001031350A1/fr

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R23/00—Arrangements for measuring frequencies; Arrangements for analysing frequency spectra
    • G01R23/16—Spectrum analysis; Fourier analysis
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N2203/003—Generation of the force
    • G01N2203/0042—Pneumatic or hydraulic means
    • G01N2203/0048—Hydraulic means
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N2203/02—Details not specific for a particular testing method
    • G01N2203/0202—Control of the test
    • G01N2203/0208—Specific programs of loading, e.g. incremental loading or pre-loading
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N2203/02—Details not specific for a particular testing method
    • G01N2203/025—Geometry of the test
    • G01N2203/0256—Triaxial, i.e. the forces being applied along three normal axes of the specimen

Definitions

  • the present invention relates to a new and improved control system for a failure mode testing system.
  • the control systems employs at least one control algorithm in order to optimize the performance of the failure mode testing system.
  • failure mode testing systems to activate failure modes has enabled manufacturers to discover latent defects or flaws which may eventually lead to the failure of a product, component or sub-component.
  • the methodology of these testing systems generally involves the application of one or more types and/or levels of stimuli to the product, component or sub-component until one or more failure modes are activated.
  • one of the stimuli includes vibration, such as that caused by striking a piston, rod, or other suitable device, against the product, component or sub-component itself, or a surface in contact with the product, component or sub-component.
  • the failure mode is activated, the failed product, component or sub-component is then either repaired, replaced, or redesigned. This process may then be repeated in order to activate and eliminate other failure modes.
  • a proprietary testing system has been developed by Entela, Inc. (Grand Rapids, Michigan) and is referred to as a failure mode verification testing system.
  • This system which is described in commonly-owned, co-pending U.S. Patent Application Serial No. 09/316,574 entitled “Design Maturity Algorithm”, filed May 21 , 1999, and U.S. Patent Application Serial No. 08/929,839 entitled “Method and Apparatus For Optimizing the Design of Products", filed September 15, 1997, employs an apparatus which is capable of generating a wide variety of stress patterns, especially six axis uniform random stress patterns, in a product, component, or sub-component in order to activate the failure modes of that particular product, component, or sub-component.
  • a six axis uniform random stress is generally defined as the stress history at a point having uniform random distribution with the stress being comprised of tension and compression stress in three orthogonal axes and torsion stress about the same three orthogonal axes.
  • Six axis uniform random stress patterns are generally defined as six axis uniform random stress at all points on a product such that the stress history of the six axis uniform random stress at each point forms a time history of non-repeating stress patterns.
  • the apparatus uses six axis uniform random actuation at one or more mounting locations of a product to produce six axis uniform random stress patterns in the product. These six axis uniform random stress patterns identify failure modes previously uncovered with other testing methodologies. Furthermore, the simultaneous introduction of other stimuli (at varying levels), such as temperature, vibration, pressure, ultraviolet radiation, chemical exposure, humidity, mechanical cycling, and mechanical loading, identify other failure modes associated with the product.
  • the apparatus employs a plurality (preferably six) of actuators, also referred to as force imparting members, that can be operated either pneumatically, hydraulically, by a combination of both pneumatic and hydraulic power, or any other force imparting mechanism.
  • actuators also referred to as force imparting members
  • a portion of the actuators, such as the cylinders, are typically mounted (including slidingly), either directly or indirectly, onto one or more support members.
  • each actuator is simply comprised of a cylinder acting in cooperation with a piston in order to produce force and torque upon a point of rotation.
  • the pressure to each actuator is preferably cycled between maximum extend pressure and maximum retract pressure in a linear "saw-tooth" manner.
  • the frequency for each actuator is slightly different. This difference in frequency causes an interference pattern of the cycling as the actuators come in and out of phase with each other. It is this difference in the frequencies of the actuators which creates a six axis uniform random stress in the product.
  • the six pneumatic actuators can be operated at frequencies of 1.8Hz, 1.9Hz, 2.0Hz, 2.1 Hz, 2.2Hz, 2.3Hz, and 2.4Hz, respectively. Therefore, as the actuators come in and out of phase with one another, the frequency content in the center will go from about 2Hz to infinity. It should be noted that other frequencies may be used for the individual actuators in order to produce an even lower frequency.
  • a portion of the actuators such as the pistons, are typically connected, either directly or indirectly, to a platform, such as a hub, upon which the product is mounted.
  • a platform such as a hub
  • the actuators are actuated, they produce a force which generates a torque about a point of rotation on the platform. It should be noted that whether a torque is generated about the point of rotation will depend upon which actuators are being actuated and in what sequence with respect to one another.
  • the force and torque are eventually transferred from the platform to the product itself, thus creating the six axis uniform random stress patterns in the product.
  • the pressure parameter concerns the amount of pressure in the air line (e.g., in a pneumatic system) in communication with the cylinder of the actuator, which is typically expressed in pounds per square inch (psi).
  • the frequency parameter concerns the frequency that each cylinder is set to, which is typically expressed in Hertz (Hz).
  • the system response of the apparatus can be measured in terms of energy E (e.g., grms or peak G) and slope m of the fast Fourier transform (FFT) of the system response.
  • a FFT is typically performed on a time history or a response.
  • an acceleration signal from an accelerometer would provide a varying signal in time.
  • the FFT of the acceleration signal would give the acceleration level vs. frequency.
  • the slope of the FFT plot i.e., response level vs. frequency
  • a desired energy level E having a desired slope m is produced by the application of appropriate levels of pressure and frequency.
  • m e.g., flat
  • the energy level were plotted on the Y-axis of a graph and the frequency level were plotted on the X-axis of that same graph, the majority of data points could be bisected by a line having a slope substantially equal to zero.
  • the energy level would be substantially constant over the entire frequency range.
  • control system for determining if the desired system response of a failure mode testing system is or is not present.
  • the control system should be capable of quickly, accurately, and if needed, constantly adjusting the operational parameters (e.g., pressure and frequency) until the desired system response is achieved and subsequently maintained.
  • General objects of the present invention are to facilitate and enhance testing of products under various conditions, to provide more comprehensive testing and to make testing more efficient by reducing the energy, time, and expense required to undertake testing.
  • Another object of the present invention is to provide a new and improved control system for a failure mode testing system.
  • Still another object of the present invention is to provide a new and improved control algorithm for a failure mode testing system.
  • a control system for a failure mode testing system having a determinable system response is provided, wherein the testing system includes a plurality of actuator cylinders, each cylinder operating at an initial pressure and an initial frequency, wherein the frequency of each of the cylinders is different, comprising: a) selecting a desired system response; b) determining the system response; c) determining whether the desired system response is present; and d) changing an operational parameter of the cylinders by a sufficient amount in order to achieve the desired system response, wherein the operational parameter is selected from the group consisting of pressure, frequency, and combinations thereof.
  • Figure 1 is a schematic of a control system for a failure mode testing system, in accordance with one aspect of the present invention
  • Figure 2 is a schematic of a pressure dither system for a failure mode testing system, in accordance with one aspect of the present invention
  • Figure 3 is a schematic of a frequency ringing system for a failure mode testing system, in accordance with one aspect of the present invention
  • Figure 4 is a schematic of a computer software program for a control system for a failure mode testing system, in accordance with one aspect of the present invention.
  • Figure 5 is a schematic of an alternative computer software program for a control system for a failure mode testing system, in accordance with one aspect of the present invention.
  • a control system employing at least one control algorithm for use in conjunction with a failure mode testing system.
  • the control algorithm enables the testing system to be operated at optimal pressure and frequency levels in order to generate a desired system response.
  • the control algorithm can be incorporated into a computer software program that can be employed to control and operate the failure mode testing system (e.g., a control system).
  • the control algorithm of the present invention is actually comprised of a number of discrete algorithms, each of which generally determine a single piece of information, based on data provided by various input sources, such as sensors, detectors, data storage mediums, and so forth.
  • one set of algorithms determines the change in energy due to pressure, the change in energy due to frequency, the change in slope due to pressure, and the change in slope due to frequency. That information is then utilized by additional algorithms to determine the average energy and slope of the system response. That information is then utilized by still additional algorithms to determine the new target energy and slope of the system response. Finally, that information is utilized by still yet another set of algorithms to determine the new target frequency and pressure to achieve the new target energy and slope of the system response.
  • FIG. 1 there is illustrated a schematic view of a non- limiting example of a control system employing at least one control algorithm, in accordance with one embodiment of the present invention.
  • the control algorithm is intended to be used in conjunction with a failure mode testing system employing an apparatus that is capable of producing six axis uniform random stress patterns in a product.
  • the actuators of the apparatus are assigned a pre-selected default pressure (P) and a pre-selected default frequency (F). These pre-selected defaults are set by the operator, and, of course, it should be noted that they may be changed or altered to meet the desired operational parameters of the testing system. Additionally, the pressure change (dp) is set at 10 psi (although any other figure may be substituted therefor), the frequency change (df) is set at 0.5 Hz (although any other figure may be substituted therefor), and the step frequency (f) is set at 0.2 Hz (although any other figure may be substituted therefor).
  • the pressure of the actuator cylinder is set to P + dp.
  • Each of the actuator cylinders are set to different frequencies, F1 , F2, F3, F4, F5, and F6, respectively.
  • F1 is equal to F + f + df.
  • the step frequency (f) is used to "step" the base frequency up to six distinct frequencies, i.e. a different frequency for each cylinder, as will become apparent from the following description.
  • F2 is equal to F + 2f + df
  • F3 is equal to F + 3f + df
  • F4 is equal to F + 4f + df
  • F5 is equal to F + 5f + df
  • F6 is equal to F + 6f + df.
  • the testing system is permitted to operate, in that the actuators are actuated.
  • the system response e.g., of the cylinders
  • E energy level
  • m slope of the fast Fourier transform of the system response
  • This information is then stored in a data storage medium and/or device (e.g., RAM, hard drive, floppy disk, CD-ROM, or the like) as an appropriate variable, under four different conditions, i.e., high pressure/high frequency (HH), high pressure/low frequency (HL), low pressure/high frequency (LH), and low pressure/low frequency (LL).
  • a data storage medium and/or device e.g., RAM, hard drive, floppy disk, CD-ROM, or the like
  • HH high pressure/high frequency
  • HL high pressure/low frequency
  • LH low pressure/high frequency
  • LL low pressure/low frequency
  • the system response information generated is stored as eight different variables, i.e., ELL (measured E when both P and F are low), ELH (measured E when P is low and F is high), EHL (measured E when P is high and F is low), EHH (measured E when both P and F are high), mLL (measured m when both P and F are low, mLH (measured m when P is low and F is high), mHL (measured M when P is high and F is low), and mHH (measured m when both P and F are high).
  • ELL measured E when both P and F are low
  • EHL measured E when P is high and F is low
  • EHH measured E when both P and F are high
  • mLL measured m when both P and F are low
  • mLH measured m when P is low and F is high
  • mHL measured M when P is high and F is low
  • mHH measured m when both P and F are high
  • decision node 50 which queries whether all four conditions have been tried (i.e., high/high, high/low, low/high, and low/low).
  • the control system prompts a change in either the pressure, frequency, and/or both, of the individual actuators, so that all four conditions are tried.
  • the first condition was low frequency/low pressure
  • the first time change requires a high frequency/low pressure condition
  • the second time change requires a high frequency/high pressure condition
  • the third time change requires a low frequency/high pressure condition.
  • the method of changing the pressure and/or frequency is by adding or removing appropriate levels of pressure (i.e., ⁇ dp) and/or frequency (i.e., ⁇ df).
  • the default frequency is 2 Hz
  • the step frequency is 0.2 Hz
  • the df is 0.5 Hz.
  • the sixth cylinder (F6) is
  • the apparatus is now operated under this particular high pressure/high frequency condition, the system response is measured (Box 30), and the energy/slope variables are calculated and stored (Box 40), and then decision node 50 is encountered.
  • the control system will prompt the apparatus to try the three remaining conditions (i.e., high pressure/low frequency, low pressure/low frequency, and low pressure/high frequency).
  • the fifth cylinder (F5) is 2.5 Hz (i.e., F (2 Hz)
  • the apparatus is now operated under this particular high pressure/low frequency condition, the system response is measured (Box 30), and the energy/slope variables are calculated and stored (Box 40), and then decision node 50 is again encountered.
  • the control system will prompt the apparatus to try the two remaining conditions (i.e., low pressure/low frequency and low pressure/high frequency).
  • the apparatus is now operated under this particular low pressure/low frequency condition, the system response is measured (Box 30), and the energy/slope variables are calculated and stored (Box 40), and then decision node 50 is again encountered.
  • the control system will prompt the apparatus to try the last remaining condition (i.e., and low pressure/high frequency).
  • the pressure With respect to the low pressure/high frequency condition, the pressure remains in the "low” condition; however, instead of subtracting the df Hz amount to the frequencies of each of the actuators, it is added.
  • the sixth cylinder (F6) is
  • Dep ((EHH + EHL) - (ELH + ELL))/(2dp) is used to determine the change in energy due to pressure (Dep).
  • Dsp ((mHH + mHL) - (mLH + mLL))/(2dp) is used to determine the change in slope due to pressure (Dsp).
  • Dsf ((mHH + mLH) - (mHL + mLL))/(2df) is used to determine the change in slope due to frequency (Dsf).
  • E1 average(EHH, EHL, ELH, ELL) is used to determine the average energy for the high pressure/high frequency, high pressure/low frequency, low pressure/high frequency, and low pressure/low frequency conditions.
  • E2 E1 + (EDESIRED - E1 )/n wherein n is greater than 1 , is used to determine the new target energy (E2). It should be noted that the desired energy (EDESIRED) is pre-selected by the operator.
  • E2 E1 + (EDESIRED - E1 )/n wherein n is greater than 1 , is used to determine the new target energy (E2). It should be noted that the desired energy (EDESIRED) is pre-selected by the operator.
  • EDESIRED desired energy
  • PNEW [(DsfE2 - DsfE1 - DefS2 + DefS1 + DepDsfP - DefDspP)/(DefDsp - DepDsf)] is used to determine the new target pressure (PNEW) to achieve the new target slope (S2). Once the PNEW is determined, it replaces P as the default pressure.
  • the system is then prompted to determine whether the EDESIRED and the SDESIRED conditions have been satisfied, as shown in Box 80.
  • the determination with respect to the EDESIRED and the SDESIRED conditions are calculated according to the following formulas: ELL ⁇ EDESIRED ⁇ EHH and mLL ⁇ SDESIRED ⁇ mHH wherein if both the EDESIRED and the SDESIRED conditions fall between their respective formulaic extremes, the system is prompted to narrow the search, as shown in Box 90.
  • the search is narrowed by dividing the dp and the df by n, respectively, wherein n is a number greater than 1.
  • the entire cycle is then repeated (starting at Box 20) with the new pressure and frequency defaults (i.e., PNEW and FNEW), and is continued until the EDESIRED and the SDESIRED fall within the narrowed ELL/EHH and mLL/mHH ranges, respectively.
  • the cycle could be repeated until the narrowed ELL/EHH and mLL/mHH ranges are within a pre-selected percentage of the EDESIRED and the SDESIRED, respectively.
  • This process is continuously repeated during the operation of the apparatus to ensure that both the EDESIRED and the SDESIRED fall within the narrowed ELL/EHH and mLL/mHH ranges.
  • the system is prompted to expand the search, as shown in Box 100.
  • the search is expanded by either multiplying the dp and the df by n (wherein n is a number greater than 1), respectively, depending on whether the EDESIRED or the SDESIRED fell outside of the respective range. This has the intended effect of increasing the amount of change in pressure and/or frequency thus increasing the ELL/EHH and/or mLL/mHH ranges, respectively.
  • the entire cycle is then repeated (starting at Box 20) with the new pressure and frequency defaults (i.e., PNEW and FNEW), and is continued until the EDESIRED and/or the SDESIRED fall within the narrowed ELIJEHH and/or mLL/mHH ranges, respectively.
  • the cycle could be repeated until the expanded ELL/EHH and mLL/mHH ranges are within a preselected percentage of the EDESIRED and the SDESIRED, respectively.
  • This process is continuously repeated during the operation of the apparatus to ensure that both the EDESIRED and the SDESIRED fall within the narrowed ELL/EHH and mLL/mHH ranges.
  • a pressure dither system for use in conjunction with a failure mode testing system.
  • the pressure dither system will overcome the previously described problem of actuators having a tendency, due to frictional forces and historesis, to gravitate towards a set point and get stuck, thus causing the actuators to improperly function.
  • Pressure dither involves the application and/or subtraction of a small amount of pressure to or from the cylinder, generally on the order of about 1-2 psi, either above or below the default pressure P and the change in pressure dp.
  • the reason for employing a pressure dither is enhanced controllability. If the cylinder of the actuator is constantly at a fixed pressure, even when running at the "high" pressure condition, it will gravitate to a set point and get stuck, as previously described. By dithering the pressure a slight amount, i.e., fluctuating the pressure slightly, this unwanted situation can be avoided.
  • the extension and/or retraction pressure of the actuator cylinder is preferably slightly different (i.e., higher and/or lower as compared to the fixed pressure) during each cycle, therefore, the probability that the cylinder will get stuck is decreased.
  • the pressure dither system can be used either independent of, or in conjunction with the control system of the present invention.
  • Figure 2 there is illustrated a schematic view of pressure dither system for a failure mode testing system, in accordance with one embodiment of the present invention.
  • the pressure dither system can be incorporated into a software program that can be employed to control and operate the failure mode testing system.
  • ditherp [((md)(maxdither)) - ((rnd)(maxdither2))] wherein rnd is a random number function between 0 and 1, and maxdither is the preselected maximum pressure difference for pressure dither (ditherp).
  • the ditherp would be -0.5 psi in this case, meaning that the pressure to the cylinder would be dithered by -0.5 psi.
  • a frequency ringing system for use in conjunction with a failure mode testing system.
  • the frequency ringing system will overcome the previously described problem of actuators receiving less energy than the other actuators, causing the apparatus to drift toward the actuator having the lowest energy level, resulting in performance problems.
  • the frequency ringing system involves reordering the frequency assigned to a particular cylinder. The reordering can either be random or cycled.
  • the frequency ringing system does not involve changing the amount of any particular frequency itself (that is controlled by the control system, specifically the control algorithm), but only the location of where that frequency is vis-a-vis the cylinders. To illustrate this concept, consider the following non-limiting example.
  • the six actuator cylinders are assigned the following respective frequencies: Cylinder 1 - 2 Hz; Cylinder 2 - 2.5 Hz, Cylinder 3 - 3 Hz; Cylinder 4 - 3.5 Hz, Cylinder 5 - 4 Hz; and Cylinder 6 - 4.5 Hz.
  • the apparatus would have a tendency to drift towards Cylinder 1 , as it has the lowest frequency, and as explained previously, the lowest energy. Therefore, the present invention overcomes this problem by indexing, reordering or reassigning the various frequencies, regardless of their magnitude, to each of the cylinders so that no one cylinder remains at the same frequency for any extended period of time.
  • present invention does not employ a simple rotation of the frequencies, i.e., moving the frequencies in order around the adjacent actuators, as that permits the formation of a "moving" or "roving" low energy actuator location. Therefore, instead of the low energy actuator being found at one particular actuator location, the low energy actuator is moving around all six actuator locations in sequence. The reordering of the frequencies, in accordance with present invention, avoids this problem.
  • the time interval between the random assignments can be for any length and can be either fixed or random.
  • the cylinders originally are set at the following frequencies: Cylinder 1 - 2 Hz; Cylinder 2 - 2.5 Hz, Cylinder 3 - 3 Hz; Cylinder 4 - 3.5 Hz, Cylinder 5 - 4 Hz; and Cylinder 6 - 4.5 Hz, and that the frequency ringing system has been programmed to randomly reorder the frequencies every one second, for a total of six seconds.
  • the frequency information for each cylinder could look like that presented in Table 1 below:
  • the frequency ringing system can be used either independent of, or in conjunction with either the control system and/or the pressure dither system of the present invention.
  • FIG. 3 there is illustrated a schematic view of frequency ringing system for a failure mode testing system, in accordance with one embodiment of the present invention.
  • the frequency ringing system can be incorporated into a software program that can be employed to control and operate the failure mode testing system.
  • Cylinder i Mode(i + Mode(C1 , 6),6) + 1 wherein i is the cylinder number (i.e., a number between 1 and 6), Mode is the remainder of the quotient between any two given numbers, and C1 is the count number (e.g., any number representing a status change in the cylinder frequency location).
  • C1 the count number (e.g., any number representing a status change in the cylinder frequency location).
  • count 1 is denoted herein as C1
  • count 2 is denoted as C2, and so forth.
  • Each cylinder is assigned an initial frequency (e.g., cylinder 1 is assigned frequency 1 (F1 ), cylinder 2 is assigned frequency 2 (F2), and so forth); thus, as the frequency is indexed or reordered at each count, the frequency assigned to a particular cylinder is changed (which can be abbreviated as cyli).
  • Count 1 the frequency ringing system as applied to cylinders 1-6 through an eight count series (e.g., 1-8) is illustrated below: Count 1
  • Cylinder 1 Mode(1 + Mode(2, 6),6) + 1
  • Cylinder 1 Mode(1 + 2,6) + 1
  • Cylinder 1 Mode(1 + Mode(3, 6),6) + 1
  • cylinder 1 at count 3 is assigned frequency 5.
  • Cylinder 1 Mode(1 + Mode(4, 6),6) + 1
  • Cylinder 1 Mode(1 + 4,6) + 1
  • Cylinder 1 Mode(1 + Mode(5, 6),6) + 1
  • Cylinder 1 Mode(1 + Mode(6, 6),6) + 1
  • Cylinder 1 Mode(1 + 0,6) + 1
  • Cylinder 1 Mode(1 ,6) + 1
  • Cylinder 1 2
  • cylinder 1 at count 6 is assigned frequency 2.
  • Cylinder 1 Mode(1 + Mode(7, 6),6) + 1
  • Cylinder 1 Mode(1 + 7,6) + 1
  • cylinder 1 at count 8 is assigned frequency 4.
  • the frequency ringing system as applied to cylinder 2 through an eight count series e.g., 1-8) is illustrated below: Count 1
  • Cylinder 2 Mode(2 + Mode(1 , 6),6) + 1
  • Cylinder 2 Mode(2 + 2,6) + 1
  • Cylinder 2 Mode(2 + Mode(3, 6),6) + 1
  • cylinder 2 at count 3 is assigned frequency 6.
  • Cylinder 2 Mode(2 + Mode(5, 6),6) + 1
  • Cylinder 2 Mode(2 + 5,6) + 1
  • Cylinder 2 Mode(2 + Mode(6, 6),6) + 1
  • Cylinder 2 Mode(2 + Mode(7, 6),6) + 1
  • Cylinder 2 Mode(2 + 7,6) + 1
  • Cylinder 2 4
  • cylinder 2 at count 7 is assigned frequency 4.
  • Cylinder 2 Mode(2 + Mode(8, 6),6) + 1
  • Cylinder 2 Mode(2 + 8,6) + 1
  • cylinder 2 at count 8 is assigned frequency 5.
  • Count 1 the frequency ringing system as applied to cylinder 3 through an eight count series (e.g., 1-8) is illustrated below: Count 1
  • Cylinder 3 Mode(3 + Mode(1 , 6),6) + 1
  • Cylinder 3 Mode(3 + 1 ,6) + 1
  • Cylinder 3 Mode(3 + Mode(2, 6),6) + 1
  • cylinder 3 at count 2 is assigned frequency 6.
  • Cylinder 3 Mode(3 + Mode(3, 6),6) + 1
  • Cylinder 3 Mode(3 + Mode(4, 6),6) + 1
  • Cylinder 3 Mode(3 + Mode(5, 6),6) + 1
  • Cylinder 3 Mode(3 + Mode(6, 6),6) + 1
  • Cylinder 3 Mode(3 + 0,6) + 1
  • Cylinder 3 Mode(3 + Mode(8, 6),6) + 1
  • Cylinder 3 Mode(3 + 8,6) + 1
  • Cylinder 3 Mode(11 ,6) + 1
  • cylinder 3 at count 8 is assigned frequency 6.
  • Count 1 Cylinder 4 Mode(4 + Mode(1 , 6),6) + 1
  • Cylinder 4 Mode(4 + 1,6) + 1
  • Cylinder 4 6
  • cylinder 4 at count 1 is assigned frequency 6.
  • Cylinder 4 Mode(4 + Mode(2, 6),6) + 1
  • Cylinder 4 Mode(4 + 2,6) + 1
  • cylinder 4 at count 3 is assigned frequency 2.
  • Cylinder 4 Mode(4 + Mode(4, 6),6) + 1
  • Cylinder 4 Mode(4 + 4,6) + 1
  • Cylinder 4 Mode(4 + Mode(6, 6),6) + 1
  • Cylinder 4 Mode(4 + 0,6) + 1
  • Cylinder 4 Mode(4 + Mode(7, 6),6) + 1
  • Cylinder 4 Mode(4 + Mode(8, 6),6) + 1
  • Cylinder 4 Mode(4 + 2,6) + 1
  • Cylinder 4 1
  • cylinder 4 at count 8 is assigned frequency 1.
  • Count 1 the frequency ringing system as applied to cylinder 5 through a six count series (e.g., 1-6) is illustrated below: Count 1
  • cylinder 5 at count 2 is assigned frequency 2.
  • cylinder 5 at count 3 is assigned frequency 3.
  • Cylinder 5 Mode(5 + Mode(4, 6),6) + 1
  • Cylinder 5 Mode(5 + 4,6) + 1
  • Cylinder 5 Mode(5 + Mode(6, 6),6) + 1
  • Cylinder 5 Mode(5 + 0,6) + 1
  • Cylinder 5 Mode(5 + Mode(7, 6),6) + 1
  • Cylinder 5 Mode(5 + Mode(8, 6),6) + 1
  • Cylinder 5 Mode(5 + 2,6) + 1
  • Cylinder 5 2
  • cylinder 5 at count 8 is assigned frequency 2.
  • Count 1 the frequency ringing system as applied to cylinder 6 through an eight count series (e.g., 1-8) is illustrated below: Count 1
  • Cylinder 6 Mode(6 + Mode(2, 6),6) + 1
  • Cylinder 6 Mode(6 + 2,6) + 1
  • cylinder 6 at count 2 is assigned frequency 3.
  • cylinder 6 at count 3 is assigned frequency 4.
  • Cylinder 6 Mode(6 + Mode(4, 6),6) + 1
  • Cylinder 6 Mode(6 + 4,6) + 1
  • Cylinder 6 Mode(11 ,6) + 1
  • Cylinder 6 Mode(6 + Mode(6, 6),6) + 1
  • Cylinder 6 Mode(6 + 0,6) + 1
  • Cylinder 6 Mode(6 + Mode(7, 6),6) + 1
  • Cylinder 6 Mode(6 + Mode(8, 6),6) + 1
  • Cylinder 6 Mode(6 + 2,6) + 1
  • cylinder 6 at count 8 is assigned frequency 3.
  • the frequency initially assigned to a particular cylinder location is being indexed or reordered among the six cylinders in such a manner that after each count, an individual cylinder's frequency has changed.
  • the frequencies are not indexed in a sequential manner such that the frequencies initially assigned to adjacent cylinders move lock step around in a circle. As previously noted, that would merely cause the low-energy site to move circularly around the actuator assemblies.
  • the present invention avoids this problem by ensuring that, sometime during a count sequence, at least one individual cylinder has a frequency of a non-adjacent cylinder.
  • C1 is the count number (e.g., any number representing a status change in the cylinder frequency location).
  • count 1 the frequency of a particular cylinder would be changed to that corresponding to count 2, and so forth.
  • control system the pressure dither system, and the frequency ringing system, can be incorporated into computer software programs, either independently or combined in various combinations.
  • FIG. 4 there is illustrated a schematic view of a computer software program for a control system for a failure mode testing system, in accordance with one embodiment of the invention.
  • FIG. 5 there is illustrated a schematic view of a computer software program for a control system for a failure mode testing system employing both a pressure dither system and a frequency ringing system, in accordance with one embodiment of the invention.

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  • Mathematical Physics (AREA)
  • General Physics & Mathematics (AREA)
  • Fluid-Pressure Circuits (AREA)

Abstract

L'invention concerne un système de commande destiné à un système de test de mode de défaillance. Ce système de commande utilise au moins un algorithme de commande permettant au système de test de fonctionner à des niveaux de pression et de fréquence optimaux de façon à produire une réponse système souhaitée, tel qu'un niveau d'énergie souhaité et une pente souhaitée de la transformation de Fourier rapide de cette réponse système. L'invention concerne également un système de variation de pression et un système de réaffectation de fréquence permettant d'optimiser le fonctionnement des cylindres d'actionnement de ce système de test de mode de défaillance. Ces trois systèmes peuvent être intégrés, indépendamment ou de manière combinée, dans un programme logiciel informatique pouvant servir à actionner et commander ledit système de test de mode de défaillance.
PCT/US2000/029507 1999-10-26 2000-10-26 Systeme de commande destine a un systeme de test de mode de defaillance WO2001031350A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU12332/01A AU1233201A (en) 1999-10-26 2000-10-26 Control system for a failure mode testing system

Applications Claiming Priority (2)

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US47745699A 1999-10-26 1999-10-26
US09/427,456 1999-10-26

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CN101819182A (zh) * 2010-03-18 2010-09-01 安徽理工大学 重构非均匀介质中缺陷形状的方法
CN112834910A (zh) * 2020-12-31 2021-05-25 成都海光集成电路设计有限公司 一种芯片半自动测试系统

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US4181026A (en) * 1978-04-19 1980-01-01 Hughes Aircraft Company Quasi-random pneumatic vibration facility and automatic frequency modulating system therefor
US4445381A (en) * 1980-02-11 1984-05-01 Russenberger Prufmaschinen AG Device for testing the vibration strength of a test body
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101819182A (zh) * 2010-03-18 2010-09-01 安徽理工大学 重构非均匀介质中缺陷形状的方法
CN112834910A (zh) * 2020-12-31 2021-05-25 成都海光集成电路设计有限公司 一种芯片半自动测试系统
CN112834910B (zh) * 2020-12-31 2023-05-26 成都海光集成电路设计有限公司 一种芯片半自动测试系统

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