Method and system for using preselected reference data in a vibration system

Abstract

The method used in the system 10 allows an operator to use preselected reference data to determine limits in the same statistical domain for one or more outputs that can be used to select reference data for use during testing. According to this method, each drive 17 is applied to the system 10, from which a controller 23 receives data. The controller 23 automatically scrutinizes the received data, comparing each received output 21 with a set of tolerance limits 112, 114 associated with that output 21. If one or more of the limits 112, 114 are violated, the output(s) 21 are identified to the operator, and the received data is not selected or otherwise used. If the received response data 21 does indeed meet all of the limits 112, 114, the data can be considered selected reference data and is then used during testing.

Description

[Technical Field]

[0001] The following discussion is provided for general background information only and is not intended to be used as an aid in determining the scope of the claimed subject matter.

[0002] The present invention relates to the control of a system, machine or process, and more particularly to obtaining reliable data in a vibration system or other actuator controlled test system. [Background technology]

[0003] Vibration systems capable of simulating loads and / or motions applied to a test specimen are commonly known. Vibration systems are highly effective in product development and are widely used for performance evaluation, durability testing, and various other purposes. For example, it is quite common in the development of automobiles, motorcycles, etc. to place a vehicle or its substructure in a laboratory environment that simulates operating conditions, such as a road or test track. Physical simulation in a laboratory requires well-known methods of data acquisition and analysis to develop drive signals that can be applied to the vibration system to replicate the operating environment. This method involves attaching transducers to the vehicle that are "remote" to the physical inputs of the operating environment. Common remote transducers include, but are not limited to, strain gauges, accelerometers, and displacement sensors, which implicitly define the operating environment of interest. The vehicle is then driven in the same operating environment, and the remote transducer responses (internal loads and / or motions) are recorded. During a simulation involving a vehicle attached to a vibration system, actuators of the vibration system are driven to replicate the remote transducer responses recorded for the vehicle in the laboratory.

[0004] However, before simulation testing can be performed, the relationship between the input drive signals to the vibration system and the response of the remote transducer must be characterized in the test laboratory. Typically, this "system identification" procedure involves obtaining a model or transfer function for each of the complete physical system (e.g., vibration system, test specimen, and remote transducer), hereafter referred to as the "physical system," calculating an inverse model or transfer function of that system, and using the inverse model or transfer function to iteratively obtain appropriate drive signals that will cause the vibration system to obtain substantially the same response from the test specimen's remote transducer in the laboratory situation as would be seen in the operating environment.

[0005] As one skilled in the art will appreciate, this process of obtaining an appropriate drive signal is unchanged when the remote transducer is not physically remote from the test system input (e.g., when the "remote" transducer is a feedback variable such as force or motion of a vibration system controller).

[0006] While the above-described systems and methods for obtaining drive signals for vibration systems have enjoyed considerable success, there is a continuing need to improve such systems, and in particular to improve the reliability of the data obtained during testing. Summary of the Invention

[0007] This Summary and Abstract herein are provided to introduce selected concepts in a simplified form that are further described below in the Detailed Description. This Summary and Abstract are not intended to identify key features or essential features of the claimed subject matter, nor are they intended to be used as an aid in determining the scope of the claimed subject matter. The claimed subject matter is not limited to implementations that solve any or all of the shortcomings discussed in the Background.

[0008] The method used in the system allows an operator to use preselected reference data to determine limits in the same statistical domain for one or more outputs that can be used to select reference data for use during testing. According to this method, each drive is applied to the system, from which a controller receives data. The controller automatically scrutinizes the received data, comparing each received output with a set of tolerance limits associated with that output. If one or more of the limits are violated, the output(s) are identified to the operator, and the received data is not selected or otherwise not used. If the received response data does indeed meet all limits, it can be considered selected reference data and is then used during testing.

[0009] The method and system may determine a first tolerance limit based on preselected reference values, which may include calculating the first tolerance limit from preselected reference values ​​corresponding to each output.

[0010] Rendering on the display to the operator can include rendering a preselected reference value for the associated output and making it clear that the preselected reference value is to be replaced with a value from the received response. In such a case, the method and system replaces each preselected reference value with the associated value from the response when the associated value does not violate the associated first tolerance limit.

[0011] In one embodiment, after rendering the one or more acceptable first limit values ​​associated with each of the response outputs to an operator on a display, input from the input device can be received from the operator, the input can include one or more adjustments to the one or more acceptable first limit values ​​associated with each of the response outputs.

[0012] The acceptable first limit value may correspond to a statistical measure of each output measured over a period of time. The statistical measure may be at least one of, but not limited to, a minimum value during the period, a maximum value during the period, an average value during the period, a root mean square value during the period, or a standard deviation value during the period. The acceptable first limit value may be associated with two or more statistical measures. The method may include deriving the first limit value by applying successive test drives to the physical system and comparing the associated received responses until the associated received responses adequately correspond to a desired response, before retrieving the acceptable first limit value associated with each of the response outputs from another portion of memory, and then storing the desired response as preselected reference data in another portion of memory.

[0013] The method and system can enable generating selected reference data for each drive used in the test, and can therefore include accessing preselected second reference data having preselected second reference values ​​for the outputs, and rendering one or more acceptable second limit values ​​associated with each of the outputs of the response to an operator on a display. After applying the first drive, a second drive is generated using a controller, and the second drive is applied to the physical system. The controller receives a second response from the physical system. For each output of the second response, the received value is compared to the associated one or more second limit values, and in the comparison, one or more outputs having a value that violates one or more of the acceptable second limit values ​​for the associated output of the second response are identified on the display. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a block diagram of an exemplary environment for implementing the present invention. [Figure 2] FIG. 1 illustrates a computer for implementing the present invention. [Figure 3A] 1 is a flow chart illustrating the steps involved in a particular phase of a prior art vibration testing method. [Figure 3B] 1 is a flow chart illustrating the steps involved in the iterative phase of a prior art vibration testing method. [Figure 3C] 1 is a flow chart illustrating the steps involved in another iterative phase of a prior art vibration testing method. [Figure 4A] FIG. 1 is a detailed block diagram of a prior art iterative process for obtaining a drive signal for a vibration system. [Figure 4B] FIG. 10 is a detailed block diagram of another prior art iterative process for obtaining a drive signal for a vibration system using the adjuster of the present invention. [Figure 5] 10 is a flowchart illustrating a process for acquiring selected reference data. [Figure 6] 10A-10C are different depictions of a GUI table rendered on the display during the method of obtaining selected reference data. [Figure 7] 10A-10C are different depictions of a GUI table rendered on the display during the method of obtaining selected reference data. [Figure 8] 10A-10C are different depictions of a GUI table rendered on the display during the method of obtaining selected reference data. [Figure 9] 10 is a GUI table for selecting output for preselected reference data. DETAILED DESCRIPTION OF THE INVENTION

[0015] FIG. 1 illustrates a physical system 10. The physical system 10 generally includes a vibration system 13 that includes a servo controller 14 and an actuator 15. In the schematic illustration of FIG. 1, actuator 15 represents one or more actuators coupled to a test specimen 18 through a suitable mechanical interface 16. Servo controller 14 provides actuator command signals 19 to actuator 15, which in turn excites test specimen 18. Suitable feedback 15A is provided from actuator 15 to servo controller 14. One or more remote transducers 20, such as displacement sensors, strain gauges, or accelerometers, located on test specimen 18 provide measured or actual responses 21. A physical system controller 23 receives actual responses 21 as feedback and calculates drives 17 as inputs to physical system 10. In one embodiment of the iterative process discussed below, physical system controller 23 generates drives 17 for the physical system 10 based on a comparison of the desired responses provided at 22 and the actual responses 21 of the remote transducers 20 on test specimen 18. Although a single channel case is shown in FIG. 1, multi-channel embodiments having a response 21 containing N response components and a drive 17 containing M drive components are common.

[0016] FIG. 2 and the associated discussion provide a brief, general description of a suitable computing environment in which the invention may be implemented. Although not required, the physical system controller 23 will be described, at least in part, in the general context of computer-executable instructions, such as program modules, being executed by a computer 30. Generally, program modules include routine programs, objects, components, data structures, etc., that perform particular tasks or implement particular abstract data types. Program modules are illustrated below using block diagrams and flowcharts. Those skilled in the art can implement these block diagrams and flowcharts into computer-executable instructions. Moreover, those skilled in the art will appreciate that the invention can be practiced using other computer system configurations, including multiprocessor systems, networked personal computers, minicomputers, mainframe computers, etc. The invention can also be practiced in distributed computing environments where tasks are performed by remote processing devices linked through a communications network. In a distributed computing environment, program modules can be located in both local and remote memory storage devices.

[0017] The computer 30 shown in FIG. 2 comprises a conventional personal or desktop computer having a central processing unit (CPU) 32, memory 34, and a system bus 36 that couples various system components, including the memory 34, to the CPU 32. The system bus 36 can be any of several types of bus structures, including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. The memory 34 includes read-only memory (ROM) and random access memory (RAM). The basic input / output (BIOS) program, containing the basic routines that help transfer information between elements within the computer 30, such as during start-up, is stored in the ROM. A storage device 38, such as a hard disk, floppy disk drive, or optical disk drive, is coupled to the system bus 36 and is used for storing programs and data. It should be understood by those skilled in the art that other types of computer-readable media accessible by a computer, such as magnetic cassettes, flash memory cards, digital video disks, random access memory, read-only memory, etc., can also be used as storage devices. Typically, a program, with or without accompanying data, is loaded into memory 34 from at least one of storage devices 38 .

[0018] Input devices 40, such as a keyboard, pointing device (mouse), etc., allow a user to provide commands to computer 30. A monitor 42 or other type of output device is further connected to system bus 36 via an appropriate interface to provide feedback to the user. Desired responses 22 may be provided as input to computer 30 through a communications link, such as a modem, or through removable media in storage device 38. Drive signals 17 are provided to physical system 10 of FIG. 1 through an appropriate interface 44 that couples computer 30 to vibration system 13, based on program modules executed by computer 30. Interface 44 also receives actual responses 21.

[0019] Before describing the present invention, it may be useful to review in detail known methods for modeling a physical system 10 and obtaining a drive 17 applied to this physical system. While described below with respect to a test vehicle, it should be understood that this prior art method and the invention discussed below are not limited to testing only vehicles, but can be used for other processes, other types of test specimens, and other substructures or their components. In addition, while the description is based on the assumption of spectral analysis-based modeling estimation and implementation, manipulations can be performed with several other mathematical techniques (e.g., Adaptive Inverse Control (AIC) type models, parametric regression techniques such as Auto Regressive Exogenous (ARX) type and state-space type models, or combinations thereof).

[0020] 3A, in step 52, a test vehicle is fitted with a remote transducer 20. In step 54, the vehicle is placed in a field operating environment of interest and the remote transducer response is measured and recorded. For example, the vehicle may be driven on a road or test track. The measured remote transducer response, which is typically analog, is stored in a digital format in a computer 30 via an analog-to-digital converter, as is commonly known.

[0021] Next, in an identification phase, an input / output model of the physical system 10 is determined. This procedure involves providing a drive 17 as an input to the physical system 10 and measuring the remote transducer response 21 as an output in step 56. The drive 17 used for model estimation can be random "white noise" with frequency content across a selected bandwidth. In step 58, an estimate of the model of the physical system 10 is calculated based on the input drive applied in step 56 and the obtained remote transducer response. In one embodiment, this is commonly known as a "frequency response function" (FRF). Mathematically, an FRF is an N x M matrix where each element is a frequency-dependent complex variable (gain and phase versus frequency). The columns of the matrix correspond to inputs, while the rows correspond to outputs. As will be appreciated by those skilled in the art, the FRF can also be obtained directly from prior testing using the physical system 10 or another system substantially similar to the physical system 10.

[0022] Inverse model H(f) -1is needed to determine the physical drive 17 as a function of the remote response in step 60. As will be appreciated by those skilled in the art, the inverse model can be calculated directly. Also, the term "inverse" model as used herein includes NxM "pseudo-inverse" models for non-square NxM systems. Furthermore, in spindle-coupled vehicle test systems, different forward and inverse models H(f), such as regions with "brake-on" and "brake-off", can be used. -1 can be used.

[0023] At this point in the prior art, the method enters an iterative phase, shown in Figures 3B and 4A, to obtain a drive 17 that produces an actual response 21 that is ideally a replica of the desired remote transducer response 22 (hereafter "desired response"). -1 is represented at 72, while the physical system (vibration system, test vehicle, remote transducer, and measurement equipment) is represented at 10. Referring to FIG. 3B , in step 78, the inverse model 72 is applied to a target response correction 77 to determine an initial drive 17 x1(t). The target response correction 77 can be the desired response 22 for the initial drive, but in most cases is reduced by a relaxation gain factor 95. The drive 17 x1(t) calculated from the inverse model 72 is then applied to the physical system 10 in step 80. The actual remote transducer response 21 (hereinafter the “actual response”) y1(t) of the physical system 10 to the applied drive 17 x1(t) is then obtained in step 86. If the complete physical system 10 were linear (allowing a relaxation gain 95 of 1), the initial drive 17 x1(t) could be used as the required drive. However, because physical systems are typically nonlinear, arriving at the correct drive 17 must be an iterative process. (As will be appreciated by those skilled in the art, a drive 17 used in a similar physical system in a previous test can be used as the initial drive.)

[0024] The iterative process involves recording a first actual response y1(t) resulting from an initial drive x1(t), comparing this actual response to the desired response 22, and calculating a response error 89 Δy1 as the difference in step 88. (The first actual response signal y1(t) is provided at 87 in FIG. 4A.) The response error 89 Δy1 is compared to a preselected threshold in step 90, and if the response error 89 exceeds the threshold, an iteration is performed. Specifically, the response error 89 Δy1 is reduced by a relaxation gain factor 95 to provide a new target response correction 77. In this embodiment, the inverse transfer function H(f) -1 is applied to the new target response correction 77 to generate a drive correction Δx 2 94 (step 91). This drive correction is added to the first drive x1(t) 17A in step 92 to obtain the second drive x2(t) 17. The iterative process (steps 80-92) is repeated until the response error 89 is reduced below a preselected threshold on all channels of the response. The last drive 17 that produced a response 21 within the predetermined threshold of the desired response 22 can then be used to test the specimen.

[0025] As described above, response error 89 Δy is typically reduced by a relaxation gain factor (or iteration gain) 95 to form target response correction 77. Iteration gain 95 sacrifices convergence rate to stabilize the iteration process and prevent iteration overshoot. Additionally, iteration gain 95 minimizes the likelihood that the test vehicle will be overloaded during the iteration process due to nonlinearities present in physical system 10. As will be appreciated by those skilled in the art, the iteration gain can be applied to drive correction 94 Δx and / or response error 89. It should be noted that in FIG. 4A , storage device 38 can be used to store desired response 22, actual response 21, and previous drive 17A during the iteration process. Of course, memory 34 can also be used. Also, dashed line 93 indicates that inverse model 72 is an estimate of the inverse system of physical system 10. The block diagram of FIG. 4A as described above can be implemented by those skilled in the art using commercially available software modules, such as those included with RPC™, available from MTS Systems Corporation, Eden Prairie, Minnesota, USA.

[0026] At this point, a modified prior art method for calculating drive can also be discussed. This modified prior art method includes the steps of the specific phase shown in FIG. 3A and many of the steps of the iterative phase shown in FIG. 3B. For convenience, the iterative steps of the modified method are shown in FIG. 3C and in the block diagram shown in FIG. 4B. As shown in FIG. 4B, the calculation of target response correction 77 is identical. However, if the response error 89 between actual response 21 and desired response 22 is greater than a selected threshold, then target response correction 77 is added to the previous target response 79A in step 97 to obtain a new target response 79 for the current iteration. Inverse model 72 is applied to target response 79 to obtain a new drive 17. As shown in FIG. 4B, an iterative gain 95 can be used for the reasons discussed above.

[0027] It should be noted that the final drive 17 used in a test will typically be associated with a certain period during the test, and that other drives will be calculated in the same manner during different periods of the test. For example, when testing a vehicle, it may be desirable to simulate the vehicle traveling on different types of roads, such as a flat highway, a gravel road, and a cobblestone road. Because each of these road surfaces has an associated sensor response that is quite different from the others, the operator must typically devise a drive to be used during the test, using the iterative process described above for each type of road surface. The complete test then includes successive periods in which drives for each type of road surface are used to control the system as desired with the test being performed, which typically involves using the drives repeatedly.

[0028] During testing, it is quite common to monitor changes in response over time to help ensure that the output response to these various drives being used remains relatively constant during the test or is within acceptable limits for a monitored parameter, such as amplitude. By way of example only, when testing a vehicle, the test may simulate 50,000 to 300,000 runs. Thus, testing can easily span multiple days, with tests taking weeks or months being not uncommon.

[0029] To ensure the integrity of the test, it is desirable to monitor one or more outputs of the response during the test and compare the current test results to the outputs of the initial response. Typically, this comparison is performed statistically, allowing for analysis of trends in the outputs. This analysis can include plotting statistical results over time. This is very useful for the operator to understand how the test is progressing and the nature of the test specimen, such as the vehicle in this example. At this point, the operator must review the initial response data to select data to be used as reference data against which subsequent test response data will be compared for trend monitoring. The selection of reference data is generally the operator's responsibility. This typically requires an operator with considerable experience, but is still laborious and subject to error. Often, initial data is used as reference data without selection, rather based on the belief that the initial data is good. If the reference data is not a good reference for the test being performed but is inadvertently used, the test may need to be repeated, which can incur significant expense and delay.

[0030] In general, the method allows an operator to use preselected reference data to determine limits in the same statistical domain for one or more outputs that can be used to select reference data for use during testing. According to this method, each drive is applied to a system from which a controller receives data. The controller automatically scrutinizes the received data, comparing each received output with a set of tolerance limits associated with that output. If one or more of the limits are violated, the output(s) are identified to the operator, and the received data is not selected or otherwise used. The operator can then mitigate the error(s) and reapply the drive(s) to obtain new response data. If the received response data does indeed meet all limits, it can be considered selected reference data and is then used during testing.

[0031] FIG. 5 illustrates a method 100 for using preselected reference data (typically stored in memory as a selected reference file) that can be used to generate a separate file of selected reference data used for monitoring during testing. The "preselected" reference data is predetermined by an operator as having reference values ​​that can be used to obtain tolerance limits for each of the outputs used, as described below. When implemented in a computer, such as controller 23, the method controls a physical system having at least one actuator coupled to the test specimen to apply a force to or displace the test specimen or a portion thereof. The physical system receives a drive signal from controller 23 that includes a plurality of drive command signals for the at least one actuator and generates a response. The response includes a plurality of outputs from sensors measuring parameters of the physical system.

[0032] In step 102, the method 100 includes accessing preselected reference data and rendering to an operator on a display of the controller one or more tolerance limit values ​​associated with each preselected reference value of the response output.

[0033] Step 102 may include rendering a GUI table on a display for the operator. An example of a GUI table is shown at 104 in FIG. 6. Table 104 includes rows with each of the outputs that form the response. Column 106 provides a descriptive identifier for each of the sensors providing the output data. Column 107 indicates a full-scale value for each output, while column 109 identifies the units of measurement for each of the outputs. Tolerance limits for each output are provided in column 112 and / or column 114. In the illustrated embodiment, column 112 provides a lower limit value for each output, while column 114 provides an upper limit value for each output. Typically, each output has a lower tolerance value and an upper tolerance value, but this should not be considered limiting. It should be noted that column 116, which displays a reference value for each of the outputs, may be blank in one embodiment before a response is received.

[0034] 5, in step 103, a drive is applied to a physical system and a response is received, as described above. It should be understood that the drive includes inputs to the physical system that vary over time. Similarly, the output, including the response, also varies over time.

[0035] In step 108, the received or measured value for each output in the response is compared to the associated limit values ​​provided in columns 112 and / or 114. If the output violates at least one of the tolerance limits, then in step 110, the output is identified to the user in table 104. Identification can take any number of forms. For example, to provide just a few examples, the row corresponding to the output that violates the tolerance limits (in this example, the received output is less than the lower tolerance limit or greater than the upper tolerance limit) can be a different color than the rest of the table and / or the text for the output can be flashed or a special icon can be rendered. In a preferred embodiment, the particular limit that has been violated can be identified using, for example, a different color, flashing, and / or an icon displayed adjacent to the violated limit. FIG. 7 shows table 104, where it can be seen in column 116A that the current output value from the received response violates the associated tolerance limit value. In the illustrated embodiment, table 104 includes a set of tables identified using tabs. This set of tables is described further below. In this example, icons 121 are used extensively in tables 104 to alert the operator when one or more outputs violate their associated tolerance limits. In this case, in the table for the illustrated tab, all outputs violate their associated tolerance limits, and other tabs also have icons 121 indicating that at least one output violates one of the tolerance limits associated with that output.

[0036] If a tolerance limit is violated, the operator typically must take some corrective action to address the problem. Such actions are numerous and do not form part of the present invention. After taking the corrective action, the operator restarts the drive and receives a response from the physical system. When none of the tolerance limits are violated, a valid or selected reference value has been obtained for each of the outputs that form the response. Such response reference values ​​are then considered selected, thereby providing selected reference data. This selected reference data can be stored as a selected reference file in step 118 and, as described above, can be used for comparison during testing to monitor the test and / or detect trends occurring during the test. FIG. 6 is an example of a table 104 with selected reference data. The reference value for each output is provided in column 116. Reviewing column 116, each reference value for each output falls between the lower tolerance limit in column 112 and the upper tolerance limit in column 114. It should also be noted that if the tolerance limits are obtained from another file stored in another portion of memory, the operator may have the ability to manually change any one of the tolerance limits in columns 112 and 114 as desired.

[0037] The tolerance limits are calculated or otherwise determined based on preselected reference values ​​for each output.

[0038] Referring to FIG. 8 , an operator can access preselected reference data (typically stored in memory and accessed as a preselected reference file) and have each of the reference values ​​for each corresponding output pre-entered into column 116. It should be understood that this pre-entry of reference values ​​occurs before a drive is applied to the physical system to obtain desired reference values ​​for another set of selected reference data to be used later during testing. Thus, at this point before the drive is applied, the values ​​in column 116 are again not used in testing; rather, they are replaced if, upon application of the drive, the output from the received response falls between the associated tolerance limits in columns 112, 114. To let the operator know that the values ​​in column 116 are preselected reference values ​​entered from a stored file, rather than reference values ​​to be used later in testing, the values ​​are visually identified as being from the preselected reference file. Any number of identification techniques, such as the use of different colors or fonts, can be used to identify the pre-entered reference values. In the illustrated embodiment, a special icon 123 is displayed adjacent to the reference value, identifying the reference value as being from a preselected file; when the controller receives a new response value that meets the associated tolerance limit, the reference value is replaced with the received value. Optionally, as shown in FIG. 7, when a tolerance limit is violated, the current value is shown in column 116A, but once a response is received, column 116 can continue to be rendered showing the preselected reference value for each output. In this embodiment, icon 123 is removed, as shown in FIG. 6, to indicate that the current value in column 116 has been selected.

[0039] If the operator receives a preselected reference value for column 116 before applying the drive to obtain a new reference value, or even if the operator manually enters a reference value in column 116, the tolerance limit can be automatically calculated, if desired. In table 104, columns 122 and 124 contain limit adjustment values ​​for each of the outputs that are used to calculate the tolerance limit values ​​in columns 112 and 114, respectively. In particular, the preselected reference value in column 116 is multiplied by the value in column 122 to obtain the tolerance limit value for column 112. Similarly, the preselected reference value in column 116 of FIG. 8 is multiplied by the value in column 124 to obtain the tolerance limit value in column 114. It should be noted that in one embodiment, automatic calculation of tolerance limits can be performed selectively on an output-by-output basis. In the illustrated embodiment, whether or not a tolerance limit value for a given output is automatically calculated is selected in column 126. In this embodiment, the value for automatic calculation of tolerance limits is specified as "statistical," whereas a different value, such as "manual," not shown, can be specified if automatic calculation of limits is not performed. Operator adjustment of one or more tolerance limits can occur in step 102. Note that the operator can adjust the tolerance limits for any output by changing the values ​​as needed in columns 122 and 124. The values ​​in columns 122 and 124, in the illustrated embodiment, include scaler amounts specified in those columns as percentages.

[0040] It should also be noted that in one embodiment, the operator can individually select whether or not an output is used when obtaining an associated reference value. In the illustrated embodiment, column 129 is provided with a check box. This check box allows the operator to indicate that for outputs that have a check in column 129, the received output value is compared to the associated tolerance limit value.

[0041] As described above, each output varies from a minimum value to a maximum value over a period of time when drive is applied. Various scales can be used to form the selected reference value. For example, Table 104 identifies six different scales that can be used. These scales include the maximum value of the output over a period of time (identified by the tab "Maximum"), the minimum value of the output received over a period of time (identified by the tab "Minimum"), the average value of the output over a period of time (identified by the tab "Mean"), the root mean square (RMS) value of the output over a period of time (identified by the tab "RMS"), the standard deviation of the values ​​of the output over a period of time (identified by the tab "Standard Deviation"), and / or the range of values ​​of the output over a period of time (identified by the tab "Range"). The operator can individually select which scale to use to obtain the selected reference data via the associated checkboxes 128 by selecting the associated checkboxes provided with each of the scale tabs. Each scale has a corresponding table similar to that shown for the scale "Max".

[0042] It should be noted that the above scale should not be considered limiting, as other statistical scales may be used. Each such statistical scale may include an associated tab in table 104. Similarly, although the tolerance limits are ranges, they should not be considered limiting, as they may take other forms than a single number depending on the scale used. For example, in the spectral domain, the tolerance limits may relate to the amplitude(s) associated with a frequency. Thus, a "value" here is broader than a single number.

[0043] The preselected reference data used to populate table 104 can be obtained in several different ways. In one embodiment, the preselected reference data is the response received for the final drive obtained using the iterative method described above with respect to Figures 3 and 4. It should be noted, however, that the preselected reference data used to obtain the selected reference data used during testing need not be obtained directly from the test specimen used during testing. Rather, in some cases, the preselected reference data can be associated with some other test specimen previously tested or with a test specimen used solely to obtain the preselected reference data.

[0044] In another embodiment, the preselected reference data can be collected from some portion of another response file having the desired output. Figure 9 shows a GUI list 130 of outputs that are rendered to the operator. Each of these outputs has an associated reference value, not shown, that the operator considers usable as a preselected reference value. In one embodiment, list 130 can be response data from a pre-test.

[0045] It should be understood that an operator will typically want to obtain selected reference data for each drive that is part of the overall test on the specimen, and therefore the method described above is repeated as necessary to obtain selected reference data for each drive.

[0046] Although the subject matter has been described in terms of specific environments, structural features, and / or methodological acts, it should be understood that the subject matter defined in the appended claims is not limited to the above-described environments, specific features, or acts, as determined by a court. Rather, the above-described environments, specific features, and acts are disclosed as example forms of implementing the claims.

Claims

1. 1. A computer-implemented method for controlling a physical system having at least one actuator coupled to a test specimen to apply a force to or displace the test specimen or a portion thereof, the physical system receiving a drive signal from a controller for the at least one actuator, the drive signal including a plurality of drive command signals, and outputting a response to the controller, the response including a plurality of outputs from sensors measuring parameters of the physical system, the method comprising: accessing preselected reference data including preselected reference values ​​for the outputs and rendering to an operator on a display one or more acceptable first limit values ​​associated with each of the outputs of the response; generating a first drive using the controller and applying the first drive to the physical system; receiving, using the controller, a first response from the physical system; For each output of the first response, comparing the received value with the associated one or more first limit values; identifying to the operator on the display one or more outputs having values ​​that violate one or more of the allowable first limit values ​​for the associated outputs of the first response; A method comprising:

2. The method of claim 1 , further comprising calculating the first acceptable limit value from preselected reference values ​​corresponding to each output.

3. 3. The method of claim 1 or 2, wherein rendering to the operator on the display includes rendering the pre-selected reference value for an associated output and making it clear that the pre-selected reference value is replaced with a value from the received response.

4. 4. The method of claim 1, further comprising: replacing each preselected reference value with the associated value from the response when the associated value does not violate the associated first acceptable limit value.

5. 5. The method of claim 1, further comprising, after rendering the one or more acceptable first limit values ​​associated with each of the outputs of the response to the operator on the display, receiving input from the operator including one or more adjustments to the one or more acceptable first limit values ​​associated with each of the outputs of the response.

6. The method of claim 5 , wherein each limit adjustment value represents a percentage.

7. 7. The method of claim 1, wherein the first acceptable limit value corresponds to a statistical measure of each output measured over a period of time, the statistical measure being at least one of a minimum value during the period, a maximum value during the period, an average value during the period, a root mean square value during the period, or a standard deviation value during the period.

8. 8. The method of claim 7, wherein one or more of the outputs have associated acceptable first limits associated with two or more statistical measures, and wherein identifying includes identifying which associated acceptable first limits of which statistical parameters have been violated.

9. 9. The method of claim 1, further comprising, before obtaining the acceptable first limit value associated with each of the outputs of the response, applying successive test drives to the physical system until an associated received response adequately corresponds to a desired response, deriving the first drive by comparing the associated received response, and then storing the desired response as the preselected reference data.

10. accessing preselected second reference data including preselected second reference values ​​for the outputs and rendering to the operator on the display one or more acceptable second limit values ​​associated with each of the outputs of the response; after applying the first drive, generating a second drive using the controller and applying the second drive to the physical system; receiving, using the controller, a second response from the physical system; and For each output of the second response, comparing the received value with the associated one or more second limit values; Identifying to the operator on the display one or more outputs having values ​​that violate one or more of the second allowable limit values ​​for the associated output of the second response; The method of any one of claims 2 to 9, further comprising:

11. 1. A test system for testing a test specimen, the test system comprising: an actuator coupleable to the test specimen for applying a force to or displacing the test specimen or a portion thereof; a sensor for providing an output of a measured parameter of the test specimen or the actuator; a memory having preselected reference data; The display and a controller coupled to the memory and the display, configured to control the actuator using a drive and to receive an associated response including the output from the sensor; Equipped with The controller rendering on the display one or more acceptable first limit values ​​associated with each of the outputs of the response, the one or more acceptable first limit values ​​being based on preselected reference values ​​in the preselected reference data for each output; generating a first drive using the controller and applying the first drive to the actuator; receiving a first response from the sensor; For each output of the first response, comparing the received value with the associated one or more first limit values; identifying to the operator on the display one or more outputs having values ​​that violate one or more of the allowable first limit values ​​for the associated outputs of the first response; A test system configured to:

12. 12. The test system of claim 11, wherein the controller is configured to calculate the first acceptable limit value from the preselected reference value corresponding to each output.

13. 13. The test system of claim 11 or 12, wherein rendering to the operator on the display includes rendering the pre-selected reference value for an associated output and making it clear that the pre-selected reference value is replaced with a value from the received response.

14. 14. The test system of claim 11, wherein the controller is configured to replace each pre-selected reference value with the associated value from the response when the associated value does not violate the associated first acceptable limit value.

15. 15. The test system of claim 11, wherein the controller is configured to receive input from the operator including one or more adjustments to the one or more acceptable first limit values ​​associated with each of the outputs of the response.

16. 15. The test system of claim 14, wherein the first acceptable limit value corresponds to a statistical measure of each output measured over a period of time, the statistical measure being at least one of a minimum value during the period, a maximum value during the period, an average value during the period, a root mean square value during the period, or a standard deviation value during the period.

17. 17. The test system of claim 16, wherein one or more of the outputs have associated acceptable first limits associated with two or more statistical measures, and wherein identifying includes identifying which associated acceptable first limits of which statistical parameters have been violated.

18. 18. The test system of claim 11, wherein the controller is configured to derive the first drive by applying successive test drives to the actuator and comparing the associated received responses until an associated received response adequately corresponds to a desired response before obtaining the acceptable first limit value associated with each of the outputs of the response, and then store the desired response as the preselected reference data.

19. The controller accessing preselected second reference data including preselected second reference values ​​for the outputs and rendering on the display one or more acceptable second limit values ​​associated with each of the outputs of the response; after applying the first drive, generating a second drive using the controller and applying the second drive to the actuator; receiving a second response from the sensor; For each output of the second response, comparing the received value with the associated one or more second limit values; Identifying on the display one or more outputs having values ​​that violate one or more of the second allowable limit values ​​for the associated outputs of the second response; 20. The test system of claim 17 configured to:

20. 20. The test system of claim 11, wherein the controller is configured to receive input from an input device after rendering the one or more acceptable first limit values ​​associated with each of the outputs of the response on the display, the input including one or more adjustments to the one or more acceptable first limit values ​​associated with each of the outputs of the response.

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