Methods and systems for using pre-compliant reference data in vibratory systems

Abstract

A method for use in a system (10) allows an operator to use pre-compliant reference data to determine limits for one or more outputs in the same statistical domain, which can be used to determine compliance of the reference data for use during testing. By this method, each drive (17) is applied to the system (10) from which the controller (23) receives data. The controller (23) automatically checks the received data carefully and compares each output (21) received with its associated set of acceptable limits (112, 114). If one or more of the limits (112, 114) are violated, the outputs (21) are identified to the operator, and the received data will be determined to be non-compliant or otherwise not to be used. When the received response data (21) does meet all the limits (112, 114), the data may be considered as compliant reference data, which is then used during the test.

Description

Background of the Invention

[0002] The following discussion is provided only for general background information and is not intended to assist in determining the scope of the claimed subject matter.

[0003] The present invention relates to the control of systems, machines, or processes. More particularly, the present invention relates to obtaining reliable data in a vibration system or other actuator-controlled test system.

[0004] Vibration systems capable of simulating the loads and / or motions applied to a test specimen are generally known. Vibration systems are widely used for performance evaluation, durability testing, and various other purposes because they are very effective in product development. For example, in the development of automobiles, motorcycles, etc., the vehicle or its substructure is typically placed in a laboratory environment that simulates operating conditions such as roads or test tracks. Physical simulation in the laboratory involves a well-known method of data acquisition and analysis in order to form a drive signal that can be applied to the vibration system to reproduce the operating environment. This method includes mounting transducers on the vehicle that are "remote" with respect 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 while recording the responses of the remote transducers (internal loads and / or motions). During the simulation when the vehicle is mounted on the vibration system, the actuators of the vibration system are driven so as to reproduce the recorded responses of the remote transducers on the vehicle in the laboratory.

[0005] However, before a simulation test can be performed, the relationship between the input drive signal of the vibration system and the response of the remote transducer must be characterized in the laboratory. Typically, this "system identification" process involves obtaining a corresponding model or transfer function of the complete physical system (e.g., the vibration system, the test specimen, and the remote transducer) (hereinafter referred to as the "physical system"); calculating the inverse model or transfer function of the physical system; and using the inverse model or transfer function iteratively to obtain a suitable drive signal for the vibration system to obtain a response from the remote transducer on the test specimen in the laboratory situation that is substantially the same as that found in the operating environment.

[0006] As those skilled in the art will understand, this process of obtaining a suitable drive signal does not change 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 the vibration system controller).

[0007] Although the above-described systems and methods for obtaining drive signals for vibration systems have achieved significant success, there is still a need for improvement in such systems. In particular, there is a need to increase the confidence in the data obtained during testing. SUMMARY OF THE INVENTION

[0008] The summary of the invention and the abstract herein are used to introduce selected concepts in a simplified form, and these selected concepts will be further described in the detailed description below. The summary of the invention and the abstract are not intended to identify the key features or essential features of the claimed subject matter, nor are they intended to be used to help determine the scope of the claimed subject matter. The claimed subject matter is not limited to embodiments that solve any or all of the disadvantages noted in the background art.

[0009] A method used in a system allows an operator to use pre-compliant reference data to determine the limits of one or more outputs in the same statistical domain, and these limits can be used to make the reference data compliant for use during testing. By this method, each drive is applied to the system from which the controller receives data. The controller automatically scrutinizes the received data and compares each received output with a set of associated acceptable limits. If one or more of the limits are violated, the operator identifies the output(s), and the received data is considered non-compliant or otherwise not used. When the received response data does satisfy all the limits, the data can be considered compliant reference data and then used during testing.

[0010] The method and system determine a first acceptable limit value based on pre-compliant reference values, and this can include calculating the first acceptable limit value according to the pre-compliant reference values corresponding to each output.

[0011] Presenting to the operator on a display can include: presenting the pre-compliant reference values of the associated outputs; and identifying that the pre-compliant reference values will be replaced with values from the received response. In this case, when the associated value from the response does not violate the associated first acceptable limit value, the method and system replace each pre-compliant reference value with the associated value.

[0012] In one embodiment, after presenting one or more first acceptable limit values associated with each output of the response to the operator on the display, an input can be received from the operator from an input device, and the input can include one or more adjustments to one or more first acceptable limit values associated with each output of the response.

[0013] The first acceptable limit value can correspond to a statistical metric of each output measured over a certain period of time. By way of non - limitation, the statistical metric can be at least one of a minimum value during a certain period, a maximum value during a certain period, an average value during a certain period, a root - mean - square value during a certain period, or a standard deviation value during a certain period. The first acceptable limit value can be associated with two or more statistical metrics. The method can include: obtaining a first drive by applying successive test drives to the physical system and comparing the associated received responses until the associated received responses appropriately correspond to the desired response, and then storing the desired response as pre - compliant reference data in another part of the memory, before obtaining the first acceptable limit value associated with each output of the response from another part of the memory.

[0014] The method and system can allow for the generation of pre - compliant reference data for each drive used in testing, and can thus include: accessing pre - compliant second reference data having pre - compliant second reference values of the outputs; and presenting to an operator, on a display, one or more second acceptable limit values associated with each output of the response. After applying the first drive, a second drive is generated using a controller and 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 with the associated one or more second limit values, wherein one or more outputs having values that violate one or more of the second acceptable limit values of the associated output of the second response are identified on the display. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a block diagram of an exemplary environment for practicing the present invention.

[0016] Figure 2 is a computer for implementing the present invention.

[0017] Figure 3A is a flowchart showing the steps involved in the identification phase of a prior - art vibration testing method.

[0018] Figure 3B is a flowchart showing the steps involved in the iterative phase of a prior - art vibration testing method.

[0019] Figure 3C is a flowchart showing the steps involved in another iterative phase of a prior - art vibration testing method.

[0020] Figure 4A is a detailed block diagram of a prior - art iterative process for obtaining a drive signal for a vibration system.

[0021] Figure 4B is a detailed block diagram of another prior art iterative process for obtaining a drive signal for a vibration system using the regulator of the present invention.

[0022] Figure 5 is a flowchart for obtaining compliance reference data.

[0023] Figures 6 to 8 are different illustrations of a GUI table presented on a display during a method for obtaining compliance reference data.

[0024] Figure 9 is a GUI table for selecting an output for pre-compliance reference data. DETAILED DESCRIPTION

[0025] Figure 1 illustrates a physical system 10. The physical system 10 generally includes a vibration system 13, which includes a servo controller 14 and an actuator 15. In Figure 1 the schematic illustration, the actuator 15 represents one or more actuators coupled to a test specimen 18 through a suitable mechanical interface 16. The servo controller 14 provides an actuator command signal 19 to the actuator 15, which in turn excites the test specimen 18. A suitable feedback 15A is provided from the actuator 15 to the servo controller 14. One or more remote transducers 20 (such as displacement sensors, strain gauges, accelerometers, etc.) on the test specimen 18 provide a measured or actual response 21. The physical system controller 23 receives the actual response 21 as feedback to calculate a drive 17, which is an input to the physical system 10. In one embodiment of the iterative process discussed below, the physical system controller 23 generates the drive 17 for the physical system 10 based on a comparison of a desired response provided at 22 with the actual response 21 of the remote transducers 20 on the test specimen 18. Although Figure 1 shown for a single-channel case, multi-channel embodiments with a response 21 including N response components and a drive 17 including M drive components are typical.

[0026] Figure 2And the related discussion provides a brief general description of a suitable computing environment in which the present 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. In general, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Block diagrams and flowcharts are used hereinafter to illustrate the program modules. Those skilled in the art can implement the block diagrams and flowcharts as computer-executable instructions. In addition, those skilled in the art will understand that the present invention can be implemented with other computer system configurations, including multiprocessor systems, networked personal computers, microcomputers, mainframe computers, etc. The present invention can also be practiced in a distributed computing environment where tasks are performed by remote processing devices linked through a communication network. In a distributed computer environment, program modules can be located in both local and remote memory storage devices.

[0027] Figure 2 The illustrated computer 30 includes a conventional personal or desktop computer having a central processing unit (CPU) 32, a 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 using any of various bus architectures, a peripheral bus, and a local bus. The memory 34 includes read-only memory (ROM) and random access memory (RAM). Basic input / output (BIOS) is stored in the ROM and contains basic routines, such as those that help transfer information between two elements within the computer 30 during startup. Storage devices 38, such as hard disks, floppy disk drives, optical disk drives, etc., are coupled to the system bus 36 and are used to store programs and data. Those skilled in the art should understand that other types of computer-readable media accessible to a computer, such as magnetic tape cartridges, flash memory cards, digital video disks, random access memory, read-only memory, etc., can also be used as storage devices. Typically, programs are loaded into the memory 34 from at least one of the multiple storage devices 38, with or without data.

[0028] Input devices 40, such as a keyboard, a pointing device (mouse), etc., allow a user to provide commands to the computer 30. A monitor 42 or other type of output device is further connected to the system bus 36 via a suitable interface and provides feedback to the user. The desired response 22 can be provided to the computer 30 as an input through a communication link, such as a modem, or through a removable medium of the storage device 38. Based on the program modules executed by the computer 30 and through a suitable interface 44 that couples the computer 30 to the vibration system 13, the drive signal 17 is provided toFigure 1 physical system 10. Interface 44 also receives the actual response 21.

[0029] Before describing the present invention, it may also be helpful to review in detail the known methods for modeling the physical system 10 and obtaining the drive 17 to be applied to the physical system. Although the following is described with respect to a test vehicle, it should be understood that such prior art methods discussed below and the present invention are not limited to only test vehicles, but can be used for other processes, test specimen types, and their substructures or components. Additionally, this description is made under the assumption of modeling estimation and implementation based on spectral analysis, although the operation can be performed by several other mathematical techniques (e.g., adaptive inverse control (AIC) type models, parametric regression techniques such as autoregressive exogenous (ARX) and state space type models, or combinations thereof).

[0030] Reference Figure 3A , at step 52, the test vehicle is equipped with the remote transducer 20. At step 54, the vehicle is placed in the field operating environment of interest, and the remote transducer response is measured and recorded. For example, the vehicle can be driven on a road or a test track. As is well known, the measured remote transducer response (usually analog) is stored in digital format in the computer 30 via an analog-to-digital converter.

[0031] Next, in the identification phase, the input / output model of the physical system 10 is determined. At step 56, the process includes providing the drive 17 as the input to the physical system 10 and measuring the remote transducer response 21 as the output. The drive 17 for model estimation can be random "white noise" having frequency components over a selected bandwidth. At step 58, an estimate of the model of the physical system 10 is calculated based on the input drive applied at step 56 and the obtained remote transducer response. In one embodiment, this is typically referred to as the "frequency response function" (FRF). Mathematically, the FRF is an N×M matrix, where each element is a frequency-dependent complex variable (the relationship between gain and phase and frequency). The columns of the matrix correspond to the inputs, and the rows correspond to the outputs. As understood by those skilled in the art, the FRF can also be obtained directly from a previous test using the physical system 10 or another system that is substantially similar to the physical system 10.

[0032] At step 60, the inverse model H(f) -1 is required to determine the physical drive 17 as a function of the remote response. As understood by those skilled in the art, the inverse model can be calculated directly. Additionally, as used herein, the term "inverse" model includes the M×N "pseudo-inverse" model for a non-square matrix N×M system. Additionally, different forward models H and inverse models H(f) can be used -1, for example, in a vehicle test system coupled to the main shaft, there are areas of "brake on" and "brake off".

[0033] At this point in the prior art, the method enters an iterative phase, as Figure 3B and Figure 4A shown, to obtain a drive 17 that produces an actual response 21, which ideally replicates the desired remote transducer response 22 (hereinafter referred to as the "desired response"). The inverse physical system model H(f) -1 is represented as 72, while the physical system (vibration system, test vehicle, remote transducer, and instrument) is represented as 10. Referring Figure 3B , at step 78, the inverse model 72 is applied to the target response correction 77 in order to determine an initial drive 17x 1 (t). The target response correction 77 can be the desired response 22 of the initial drive, but most commonly it is reduced by a relaxation gain factor 95. Then, at step 80, the drive 17x 1 (t) calculated from the inverse model 72 is applied to the physical system 10. Then, at step 86, the actual remote transducer response 21 (hereinafter referred to as the "actual response") y 1 (t) of the physical system 10 to the applied drive 17x 1 (t) is obtained. If the complete physical system 10 is linear (allowing the relaxation gain 95 to be one), then the initial drive 17x 1 (t) can be used as the required drive. However, since physical systems are generally non - linear, the correct drive 17 must be obtained through an iterative process. (As understood by those skilled in the art, the drive 17 used in previous tests of similar physical systems can be used as the initial drive.)

[0034] The iterative process involves recording the first actual response y 1 (t) produced by the initial drive x 1 (t), comparing it with the desired response 22, and calculating a response error 89 Δy 1 as the difference at step 88. (The first actual response signal y Figure 4A is provided at 87 of 1 (t).) At step 90, the response error 89 Δy 1 is compared with a pre - selected threshold, and if the response error 89 exceeds the threshold, an iteration is performed. Specifically, the response error 89 Δy 1 is reduced by the 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 create a drive correction Δx 294 (Step 91), and in Step 92, this drive correction is added to the first drive x 1 (t) 17A to obtain the second drive x 2 (t) 17. The iterative process (Steps 80 - 92) is repeated until the response error 89 on all response channels is reduced below a pre - selected threshold. The final drive 17 that produces the response 21 within the predetermined threshold of the desired response 22 can then be used to perform the specimen test.

[0035] As described, the response error 89 Δy is typically reduced by a relaxation gain factor (or iteration gain) 95 to form the target response correction 77. The iteration gain 95 stabilizes the iterative process and trades off between the convergence rate and iteration overshoot. In addition, the iteration gain 95 minimizes the likelihood that the test vehicle will be overloaded during the iterative process due to the non - linearities present in the physical system 10. As will be understood by those skilled in the art, the iteration gain can be applied to the drive correction 94 Δx and / or the response error 89. It should be noted that in Figure 4A the storage device 38 can be used to store the desired response 22, the actual response 21, and the previous drive 17A during the iterative process. Of course, the memory 34 can also be used. In addition, the dashed line 93 indicates that the inverse model 72 is an estimate of the inverse model of the physical system 10. As described above, Figure 4A the block diagram of TM can be implemented by those skilled in the art using commercially available software modules, such as the software modules included in the RPC

[0036] At this point, it is also possible to discuss the prior art methods for calculating drive corrections. The modified prior art methods include Figure 3A the steps of the identification phase shown in Figure 3B and many steps of the iterative phase shown in Figure 3C . For convenience, the iterative steps of the modified method are shown in Figure 4B and the block diagram is as shown in Figure 4B . As shown in Figure 4B , the calculation of the target response correction 77 is the same. However, if the response error 89 between the actual response 21 and the desired response 22 is greater than the selected threshold, then in Step 97 the target response correction 77 is added to the previous target response 79A to obtain the new target response 79 for the current iteration. The inverse model 72 is applied to the target response 79 to obtain the new drive 17. As shown in Figure 4B , the iteration gain 95 can be used for the reasons described above.

[0037] It should be noted that the last drive 17 to be used for testing is typically associated with a period of time during the test, and for different time periods of the test, other drives will be calculated in the same way. For example, in the case of testing a vehicle, it may be desirable to simulate the vehicle traveling on different types of roads, such as traveling on a smooth highway, traveling on a gravel road, traveling on a cobblestone road, etc. Since the associated sensor responses for each of these road surfaces are quite different, the operator typically has to use the iterative process described above for each type of road surface during the test to arrive at the drive to be used. The complete test then includes consecutive time periods in which the drives for each type of road surface are used to control the system according to the needs of the test to be performed, which typically includes repeated use of the drives multiple times.

[0038] During the test, it is very common to monitor the change of the response over time, which helps to ensure that the output in the responses to these different drives used remains relatively constant, or stays within the admissible limits of the monitored parameter (such as amplitude) during the test. Taking only the vehicle test as an example, the test can simulate traveling 50,000 to 300,000 kilometers. Therefore, the test can easily span multiple days, and it is not uncommon for the test time to be as long as several weeks or months.

[0039] 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 with the outputs of the initial response. Usually, the comparison can be carried out by statistical methods and the trend of the output can be analyzed, which can include plotting the change of the statistical results over time as a graph. This is very helpful for the operator to understand how the test is progressing and the nature of the test specimen (such as the vehicle in this example). Currently, the operator will need to carefully check the initial response data to make the data to be used as reference data compliant, compare this reference data with the subsequent test response data for trend monitoring. Verifying the compliance of the reference data is typically the responsibility of the operator. This usually requires the operator to have quite rich experience, but nevertheless, it is very laborious and still may go wrong. In many cases, the initial data is used as reference data without any compliance check, but it is believed to be good. If the reference data is not a good reference for the test to be performed but is inadvertently used, the test may need to be repeated, which can be quite costly and cause significant delays.

[0040] Generally, a method allows an operator to use pre-compliant reference data to determine limits for one or more outputs within the same statistical domain, which limits can be used to make the reference data compliant for use during testing. By this method, each drive is applied to a system from which the controller receives data. The controller automatically scrutinizes the received data, comparing each received output to a set of acceptable limits associated therewith. If one or more of these limits are violated, those outputs are identified to the operator and the received data is considered non-compliant or otherwise not used. The operator can then reduce the error(s) and re-apply the drive(s) to obtain new response data. When the received response data does satisfy all limits, the data can be considered compliant reference data and then used during testing.

[0041] Figure 5 Method 100, which uses pre-compliant reference data (usually stored in memory as a compliant reference file), is shown and can be used to generate another qualified reference data file for use during monitoring. The “pre-compliant” reference data has previously been determined by the operator to have reference values that can be used to obtain acceptable limit values for each output used as described below. When implemented on a computer such as controller 23, the method controls a physical system having at least one actuator coupled to a test specimen to apply a force or displace the test specimen or a portion of the test specimen. The physical system receives a drive from controller 23, the drive including 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.

[0042] At step 102, method 100 includes accessing the pre-compliant reference data and presenting to the operator, on a display of the controller, one or more acceptable limit values associated with each pre-compliant reference value of the outputs of the response.

[0043] Step 102 can include presenting a GUI table to the operator on the display, an example of which is in Figure 6is shown at 104 in. Each row in Table 104 includes each output that forms the response. Column 106 provides a descriptive identifier for each sensor that provides output data. Column 107 indicates the full-scale value of each output, while column 109 identifies the unit of measurement for each output. Columns 112 and / or 114 provide the acceptable limit values for each output. In the illustrated embodiment, column 112 provides the lower limit value for each output, and column 114 provides the upper limit value for each output. Although typically each output will have an acceptable lower limit value and an acceptable upper limit value, this should not be considered restrictive. It should be noted that in one embodiment, column 116, which displays the reference value for each output, may be blank before the response is received.

[0044] Return reference Figure 5 , at step 103, as described above, a drive is applied to the physical system and a response is received. It should be understood that the drive includes inputs to the physical system that vary over a period of time. Similarly, the outputs, including the response, will also vary over time.

[0045] At step 108, the value or measurement received for each output of the response is compared with the associated limit values provided in columns 112 and / or 114. If an output violates at least one of these acceptable limit values, then at step 110 that output is identified to the user in Table 104. The identification can take various forms. For example, the row corresponding to the output that violates the acceptable limit value (in this example, the received output is less than the acceptable lower limit or greater than the acceptable upper limit) can be a different color from the rest of the table, and / or the text of the output can blink, or a special icon can be presented, to name just a few examples. In a preferred embodiment, the specific limit value that has been violated can be identified, for example, using a different color, blinking, and / or a certain icon displayed next to the limit value that has been violated. Figure 7 Table 104 is shown, where the current output value from the received response has been found to violate the associated acceptable limit value in column 116A. In the illustrated embodiment, Table 104 includes a set of tables identified by labels, as further described below. In this example, icon 121 is generously used in Table 104 to warn the operator whether one or more outputs have violated their associated acceptable limit values. In this case, for the shown label, all outputs have violated the acceptable limit values associated with them in the table, while other labels also have icon 121, indicating that at least one output has violated one of its associated acceptable limit values.

[0046] If an acceptable limit has been violated, the operator will typically need to take some corrective action to address the issue. There are many such actions and they do not form part of the present invention. After taking the corrective action, the operator will initiate the drive again and receive a response from the physical system. When no acceptable limit has been violated, each output that forms the response has an effective or compliant reference value. This reference value for the response is then considered compliant, thereby providing compliant reference data that can be stored as a compliant reference file at step 118 and can be used as described above for comparison during testing to monitor the test and / or detect trends that occur during testing. Figure 6 is an example of Table 104 with qualified reference data. The reference values for each output are provided in column 116. Looking back at column 116, each reference value for each output falls between the acceptable lower limit in column 112 and the acceptable upper limit value in column 114. It should also be noted that if desired, the operator has the ability to manually change either of the acceptable limit values in columns 112 and 114 if the acceptable limit values are obtained from another file stored in another part of the memory.

[0047] The acceptable limit values are calculated or otherwise determined based on the pre-compliant reference values for each output.

[0048] Reference Figure 8 , the operator can access the pre-compliant reference data (typically stored in memory and accessed as a pre-compliant reference file) and pre-fill each reference value for each corresponding output into column 116. It should be understood that this pre-filling of the reference values is done before the drive is applied to the physical system to obtain the desired reference values for another set of compliant reference data that will be used during testing later. Thus, the values in column 116 will not be used again for testing before the drive is applied, but rather will be replaced if the output from the received response when the drive is applied falls between the associated acceptable limit values in columns 112 and 114. To make the operator aware that the values in column 116 are not the reference values to be used later in the test but are pre-compliant reference values filled in from the stored file, the value is identified on the screen as coming from the pre-compliant reference file. Any number of identification techniques can be used to identify the pre-filled reference values, such as using a different color or font. In the illustrated embodiment, a special icon 123 is shown near the reference value, thus identifying the reference value as coming from the pre-compliant file, and when the controller receives a new response value that meets the associated acceptable limit values, the special icon will be replaced with the received value. If desired, as Figure 7As shown, when an acceptable limit value has been violated, the current value is shown in column 116A, and column 116 can still be presented upon receipt of a response, showing the pre-compliance reference value for each output. In this embodiment, icon 123 is removed, as Figure 6 shown, to indicate that the values now in column 116 are already in compliance.

[0049] If the operator receives the pre-compliance reference value for column 116, or even if the operator is to manually enter a reference value in column 116 before applying drive to obtain a new reference value, the acceptable limit value can be automatically calculated as needed. In Table 104, columns 122 and 124 include limit adjustment values for each output for calculating the acceptable limit values in columns 112 and 114, respectively. Specifically, the pre-compliance reference value in column 116 is multiplied by the value in column 122 to arrive at the acceptable limit value for column 112. Similarly, Figure 8 the pre-compliance reference value in column 116 is multiplied by the value in column 124 to arrive at the acceptable limit value for column 114. It should be noted that in one embodiment, the automatic calculation of the acceptable limit value can be selectively used for each output. In the illustrated embodiment, it is selected in column 126 whether to automatically calculate the acceptable limit value for a given output. In this embodiment, the value used for automatically calculating the acceptable limit value is identified as "statistical", while if the automatic calculation of the limit value is not performed, a different value, such as "manual" (not shown), can be identified. Operator adjustment of one or more acceptable limit values can be performed in step 102. It should be noted that the operator can adjust the acceptable limit value for any output by changing the values in columns 122 and 124 as needed, and in the illustrated embodiment, the values in these two columns include scalars identified herein as percentages.

[0050] It should also be noted that in one embodiment, the operator can individually select whether an output will be used to obtain the associated reference value. In the illustrated embodiment, column 129 provides a checkbox that allows the operator to indicate that the output value will be compared with the associated acceptable limit value, and the output value is received for the output having a check in column 129.

[0051] As described above, as the drive is applied, each output changes from a minimum value to a maximum value over a period of time. A variety of metrics can be used to form a compliance reference value. For example, Table 104 identifies six different metrics that can be used. These metrics include the maximum value of the output over a period of time (identified by the label "Maximum"), the minimum value of the output received over a period of time (identified by the label "Minimum"), the average value of the output over a period of time (identified by the label "Average"), the RMS (root mean square) value of the output over a period of time (identified by the label "RMS"), the standard deviation of the output values over a period of time (identified by the label "Standard Deviation"), and / or the range of the output values over a period of time (identified by the label "Range"). By selecting the associated checkbox 128 provided in each metric label, the operator can individually select, via the associated checkbox, which metrics to use to obtain compliance reference data. Each metric has a corresponding table, similar to the table shown for the metric "Maximum".

[0052] It should be noted that the foregoing metrics should not be considered restrictive, as other statistical metrics can be used, and each such statistical metric can include the associated label in Table 104. Similarly, the acceptable limit values as a range should not be considered restrictive, as depending on the metric used, the acceptable limit values can take another form rather than a single number. For example, in the frequency domain, the acceptable limit values can be associated with the (multiple) amplitudes associated with the frequency. Thus, the "value" herein is broader than a single number.

[0053] The pre-compliance reference data used to populate Table 104 can be obtained in a variety of different ways. In one embodiment, the pre-compliance reference data is the response received for the final drive, which is obtained using the iterative method described above with respect to FIGS. 3 and 4. However, it should be noted that the pre-compliance reference data used to obtain the compliance reference data to be used during testing does not need to be directly obtained from the test specimen to be used during testing. Instead, in some cases, the pre-compliance reference data can be associated with some other test specimen that was previously tested or a test specimen used only to obtain the pre-compliance reference data.

[0054] In another embodiment, the pre-compliance reference data can be combined from portions of other response files having the desired output. Figure 9 A GUI list 130 of the outputs presented to the operator is shown, and each output has an associated reference value (not shown) that the operator deems available as a pre-compliance reference value. In one embodiment, the list 130 can be response data from a previous test.

[0055] It should be understood that typically an operator desires to obtain compliance reference data for each drive, which forms part of an overall test of the test specimen. Accordingly, the above method is repeated as necessary in order to obtain reference data compliant for each drive.

[0056] Although the subject matter has been described in language specific to particular 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 environments, specific features, or acts described above that have been held by a court. Rather, the above-described environments, specific features, and acts are disclosed as example forms of implementing the claims.

Claims

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 actuation from a controller for the at least one actuator, the actuation 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 comprises: accessing pre-compliant reference data including pre-compliant reference values for the outputs and presenting, on a display, one or more first acceptable limit values associated with each output of the response to an operator; using the controller to generate a first drive and applying the first drive to the physical system; using the controller to receive 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; and identifying, on the display, to the operator one or more outputs having values that violate one or more of the first acceptable limit values associated with the associated output of the first response.

2. The method of claim 1, further comprising calculating the first acceptable limit values based on pre-compliant reference values corresponding to each output.

3. The method according to any one of claims 1 to 2, wherein, presenting to the operator on the display includes: presenting the pre-compliant reference value for the associated output; and identifying that the pre-compliant reference value is to be replaced with a value from the received response.

4. The method according to any one of claims 1 to 3, further comprising replacing each pre-compliant reference value with the associated value when the associated value from the response does not violate the associated first acceptable limit value.

5. The method according to any one of claims 1 to 4, further comprising, after presenting, on the display, the one or more first acceptable limit values associated with each output of the response to the operator, receiving an input from the operator, the input including one or more adjustments to the one or more first acceptable limit values associated with each output of the response.

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

7. The method according to any one of claims 1 to 6, wherein, the first acceptable limit values correspond 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. The method of claim 7, wherein, The one or more outputs have associated first acceptable limit values, the first acceptable limit values being associated with two or more statistical metrics, and wherein the identification includes identifying which associated first acceptable limit value of which statistical parameter has been violated.

9. The method according to any one of claims 1 to 8, further comprising: Before obtaining the first acceptable limit value associated with each of the outputs of the response, obtaining the first drive by applying successive test drives to the physical system and comparing the associated received responses until the associated received responses suitably correspond to the desired response, and then storing the desired response as the pre-compliance reference data.

10. The method according to any one of claims 2 to 9, further comprising: Accessing pre-compliance second reference data, the pre-compliance second reference data including pre-compliance second reference values of the outputs, and presenting to the operator on the display one or more second acceptable 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 a second response from the physical system using the controller; For each output of the second response, comparing the received value with the associated one or more second limit values; and Identifying on the display to the operator one or more outputs having values that violate one or more of the second acceptable limit values of the associated outputs of the second response.

11. A test system for testing a test specimen, the test system comprising: An actuator that can be coupled to the test specimen to apply a force to or displace the test specimen or a part of the test specimen; A sensor for providing an output of a measured parameter of the test specimen or the actuator; A memory having pre-compliance reference data; A display; and A controller coupled to the memory and the display and configured to control the actuator using a drive and to receive an associated response including an output from the sensor, and wherein the controller is configured to Present on the display one or more first acceptable limit values associated with each of the outputs of the response, the one or more first acceptable limit values being based on pre-compliance reference values in the pre-compliance 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; and Identify, on the display, to the operator one or more outputs having values that violate one or more of the first acceptable limit values for the associated outputs of the first response.

12. The test system according to claim 11, wherein, the controller is configured to calculate the first acceptable limit values according to the pre-compliance reference values corresponding to each output.

13. The test system according to any one of claims 11 to 12, wherein, presenting to the operator on the display includes: presenting the pre-compliance reference values of the associated outputs; and identifying that the pre-compliance reference values will be replaced with values from the received response.

14. The test system according to any one of claims 11 to 13, wherein, the controller is configured to replace each pre-compliance reference value with the associated value when the associated value from the response does not violate the associated first acceptable limit value.

15. The test system according to any one of claims 11 to 14, wherein, the controller is configured to receive an input from the operator, the input including one or more adjustments to one or more of the first acceptable limit values associated with each output of the response.

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

17. The test system according to claim 16, wherein, the one or more outputs have associated first acceptable limit values associated with two or more statistical metrics, and wherein the identification includes identifying which associated first acceptable limit value of which statistical parameter has been violated.

18. The test system according to any one of claims 11 to 17, wherein, the controller is configured to obtain the first drive by applying successive test drives to the actuator before obtaining the first acceptable limit values associated with each output of the response, and compare the associated received responses until the associated received responses suitably correspond to the desired response, and then store the desired response as the pre-compliance reference data.

19. The test system according to claim 17, wherein, the controller is configured to access pre-compliance second reference data, the pre-compliance second reference data including pre-compliance second reference values for the output, and present one or more second acceptable limit values associated with each output of the response on the display; after applying the first drive, generate a second drive using the controller and apply the second drive to the actuator; receive a second response from the sensor; For each output of the second response, compare the received value with the associated one or more second limit values; and Identify on the display one or more outputs having values that violate one or more of the second acceptable limit values of the associated output of the second response.

20. The test system according to any one of claims 11 to 19, wherein, the controller is configured to receive an input from an input device after presenting on the display the one or more first acceptable limit values associated with each of the outputs of the response, the input including one or more adjustments to the one or more first acceptable limit values associated with each of the outputs of the response.

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