caltester:caltester_mode_overview
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caltester:caltester_mode_overview [2024/08/01 15:16] – [Estimating the Force Platform Location] wikisysop | caltester:caltester_mode_overview [2025/03/31 17:22] (current) – wikisysop | ||
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The functionality is **now available in Visual3D when a CalTester license key is provided**. There is also a stand-alone version of Visual3D that ONLY supports the CalTester, and these options now replace the older software. Users of the old software should have access to the new software automatically when they log into our web downloads page. | The functionality is **now available in Visual3D when a CalTester license key is provided**. There is also a stand-alone version of Visual3D that ONLY supports the CalTester, and these options now replace the older software. Users of the old software should have access to the new software automatically when they log into our web downloads page. | ||
- | **UPDATE:** The standalone CalTester-Plus software application has been discontinued and replaced with a newer CalTester | + | **UPDATE:** The standalone CalTester-Plus software application has been discontinued and replaced with a newer CalTester |
As a reminder, always go to the CalTester tab first, before opening any CalTester related data files. | As a reminder, always go to the CalTester tab first, before opening any CalTester related data files. | ||
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Accurate and reliable kinematics and kinetics data are essential to the appropriate application of movement analysis data for clinical and research purposes. Proper laboratory calibration includes the accurate determination of the positions of the force platform(s) and cameras in the laboratory coordinate system, as well as correct setting of [[Visual3D: | Accurate and reliable kinematics and kinetics data are essential to the appropriate application of movement analysis data for clinical and research purposes. Proper laboratory calibration includes the accurate determination of the positions of the force platform(s) and cameras in the laboratory coordinate system, as well as correct setting of [[Visual3D: | ||
- | {{: | + | {{: |
CalTester is an essential tool for laboratories that: | CalTester is an essential tool for laboratories that: | ||
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Functionality is based on recording the position and orientation of a standard commercially available precision mechanical testing device [[CalTester: | Functionality is based on recording the position and orientation of a standard commercially available precision mechanical testing device [[CalTester: | ||
- | **The design of the [[CalTester: | + | ==== The design of the MTD2 device allows a force to be applied to the surface of the force platform without any applied moment.==== |
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- | The [[CalTester: | + | The [[CalTester: |
Within the CalTester mode there are two classes of functionality: | Within the CalTester mode there are two classes of functionality: | ||
- | **Estimate errors in the Center of Pressure and Orientation of the Force Vector.** | + | ====Estimate errors in the Center of Pressure and Orientation of the Force Vector.==== |
- | Estimate the errors between the force platform recordings and the Motion Capture System. This simple test takes only a few minutes, could be performed prior to any data collection, and provides reassurance that your data collection is sound.\\ \\ The following calculations and explanations are from the [[https:// | + | Estimate the errors between the force platform recordings and the Motion Capture System. This simple test takes only a few minutes, could be performed prior to any data collection, and provides reassurance that your data collection is sound.\\ \\ The following calculations and explanations are from the [[https:// |
+ | |||
+ | ====Section I : Calculating the rod orientation variable under the assumed condition of static equilibrium==== | ||
+ | |||
+ | Free-body diagram of testing device: Fp, ground reaction force; Fg, gravitational force (weight); Fa, applied force; r, position vector between tips (p to a) of testing device rod:\\ {{: | ||
**Estimate the position and orientation of a force platform, instrumented treadmill, or instrumented stair that minimizes these errors..** | **Estimate the position and orientation of a force platform, instrumented treadmill, or instrumented stair that minimizes these errors..** | ||
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Force Platform signals are computed in compliance with [[http:// | Force Platform signals are computed in compliance with [[http:// | ||
- | **About [[Visual3D: | + | ** About [[Visual3D: |
+ | |||
Force Platforms, Instrumented Treadmills, Instrumented Stairs are examples of external force measuring devices. Each of these devices generates signals that are recorded by the Motion Capture System.\\ \\ These signals are used in conjunction with a set of parameters to compute a [[Visual3D: | Force Platforms, Instrumented Treadmills, Instrumented Stairs are examples of external force measuring devices. Each of these devices generates signals that are recorded by the Motion Capture System.\\ \\ These signals are used in conjunction with a set of parameters to compute a [[Visual3D: | ||
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CalTesterPlus requires consistent data in order to make the correct calculations. | CalTesterPlus requires consistent data in order to make the correct calculations. | ||
- | **Assumptions About Data Being Used.** | + | ==== Assumptions About Data Being Used. ===== |
- | The program makes the following assumptions about the data that is being used:\\ \\ * Markers must be labeled in the c3d file produced by the motion capture system.\\ * Target selection plays a key role in computing the correct output. If the wrong targets are chosen, this program may list the force platform center in an extremely odd location. Due to the nuances of marker labeling that differ between labs, it is difficult to determine which targets on the CalTester correspond to internal vectors of location data within the c3d file. In the case of static, custom target locations, it becomes impossible. That is why the burden of correct identification falls on the user.\\ * That markers are named consistently in the trials you are using. Even though it is possible for you to name the CalTester Rod markers whatever you want it is essential that they be named consistently; | + | The program makes the following assumptions about the data that is being used: |
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In order to use the CalTesterPlus program you need a set of properly collected data for each force platform you wish to calibrate. | In order to use the CalTesterPlus program you need a set of properly collected data for each force platform you wish to calibrate. | ||
- | **Data Collection for Error Report.** | + | ==== Data Collection for Error Report.==== |
- | In order to use the CalTesterPlus program you need a set of properly collected data for each force platform you wish to calibrate. To collect a useful motion trial for the report mode follow the following process.\\ \\ * Each example motion trial that is downloaded with the CalTesterPlus program meets these criteria.\\ \\ - Set up your capture volume making sure that all force platforms and cameras are in the positions that they will remain in for following data collections.\\ - Before you begin collecting the trial place the [[CalTester: | + | |
+ | In order to use the CalTesterPlus program you need a set of properly collected data for each force platform you wish to calibrate. To collect a useful motion trial for the report mode follow the following process. | ||
- | **Data Collection for Force Platform Location. (FP Loc Tab)** | + | |
- | To collect a useful static trial for CalTester follow the following process.\\ \\ - Set up your capture volume making sure that all force platforms and cameras are in the positions that they will remain in for following data collections.\\ - Make sure the targets on the jig are visible\\ - Place the [[CalTester: | + | |
+ | * Before you begin collecting the trial place the [[CalTester: | ||
+ | * Zero the force platform so that it will not record the force produced by the CalTester base. | ||
+ | * Begin the data capture with the [[CalTester: | ||
+ | * After a second place the CalTester Rod in one of the CalTester base platform' | ||
+ | * Press down on the rod with a load of at least 200 N. | ||
+ | * Move the rod in both the frontal and sagittal direction: | ||
+ | * Keeping the end of the rod on the force platform stationary move the upper portion of the rod from vertical to 30 degrees from vertical, back to vertical and then 30 degrees in the opposite direction. This movement should take no less than 3 seconds and the force applied should be equal to or greater than 200 N. | ||
+ | * Move the rod in both the frontal and sagittal direction: | ||
+ | * Keeping the end of the rod on the force platform stationary move the upper portion of the rod in an arc (circular motion). | ||
+ | * This movement should be approximately 3 seconds long and the force applied should be equal to or greater than 200 N. | ||
+ | * Focus more on applying a greater force than moving the rod in an large arc. Also make sure that the plate doesn' | ||
+ | * There should be a minimum of three trials collected per force platform. Ideally there should be 5, one near each corner of the force platform and one near the center of the force platform. | ||
+ | |||
+ | ==== Data Collection for Force Platform Location. (FP Loc Tab) ==== | ||
+ | To collect a useful static trial for CalTester follow the following process. | ||
+ | |||
+ | * Set up your capture volume making sure that all force platforms and cameras are in the positions that they will remain in for following data collections. | ||
+ | * Make sure the targets on the jig are visible | ||
+ | * Place the [[CalTester: | ||
+ | * Zero the force platform so that it will not record the force produced by the CalTester base. | ||
+ | * Begin the trial with the [[CalTester: | ||
+ | * After a second place the CalTester Rod in one of the CalTester base platform' | ||
+ | * Press down firmly on the Rod with a load of at least 200 N. | ||
+ | * Keep the Rod aligned vertically and motionless during the trial. | ||
+ | * The trial needs to be at least 1 second long. | ||
+ | * There should be a minimum of three trials collected per force platform. Ideally there should be 8 or more, with at least one near each corner of the force platform and one near the center of the force platform. | ||
===== CalTester Toolbar ===== | ===== CalTester Toolbar ===== | ||
- | Tool Bar{{: | + | Tool Bar{{: |
+ | |||
+ | {{: | ||
===== Error Report ===== | ===== Error Report ===== | ||
- | **Creating the CalTester Error Report** | + | ====Creating the CalTester Error Report==== |
- | The report capabilities of the CalTester tab creates an error report based on collection trials.\\ \\ **1. Add C3D files**\\ \\ In order to open a C3d file for use in the CalTester tab you must first navigate to the CalTester tab and leave it active. The C3D files are then opened by clicking on the open button. {{: | + | |
+ | The report capabilities of the CalTester tab creates an error report based on collection trials. | ||
+ | |||
+ | - **Add C3D files** \\ In order to open a C3d file for use in the CalTester tab you must first navigate to the CalTester tab and leave it active. The C3D files are then opened by clicking on the open button. {{: | ||
+ | - **Check Report** \\ Once the files are loaded the right side of the CalTester tab will show the first page of the CalTester report. You can navigate between the three report pages by using the page buttons in the tool bar. {{: | ||
+ | - **Print Report**\\ | ||
+ | - **Understanding the Report**\\ A detailed explanation of how to understand the report that CalTester produces can be found [[caltester: | ||
+ | |||
+ | **Note:** If there appears to be errors or discrepancies in the report or the 3D-view check that the markers have been identified correctly and that the rod dimensions are correct using the Modify CalTester Rod Dimensions button. {{: | ||
+ | |||
+ | ==== Understanding Report Page 1==== | ||
+ | |||
+ | The Laboratory Calibration Test Report includes the mean, standard deviation, and range (minimum and maximum) of the four report variables. These are provided on graphs and with numerical values. | ||
- | **Understanding Report Page 1** | + | - **The background on the file:** the top of the report contains the summary of the c3d file being used. This includes the number of frames used, the minimum force settings (for CalTester and Visual3D), and the dates the c3d file was collected and when the report was created.\\ {{: |
- | The Laboratory Calibration Test Report includes the mean, standard deviation, and range (minimum and maximum) of the four report variables. These are provided on graphs and with numerical values.\\ \\ **(1) The background on the file:** the top of the report contains the summary of the c3d file being used. This includes the number of frames used, the minimum force settings (for CalTester and Visual3D), and the dates the c3d file was collected and when the report was created.\\ \\ {{: | + | - |
+ | - **The Difference in Force Orientation Error:** this is the angle (in degrees) between the applied force reaction vector (i.e., the ground reaction force minus the weight of the calibration-testing rod) and the orientation of the long axis of the rod, as determined from the target data.\\ **Note:** The force orientation variable is calculated from the dot product of this predicted unit vector and the vector along the axis of the rod as determined with the motion capture system.\\ {{: | ||
+ | - **(The differences in CoP (for x, y, and z):** these are the components of the displacement vector between the CoP location measured by the force platform and the endpoint of the calibration-testing rod (adjusted for the specified vertical height above the force platform).\\ \\ {{: | ||
- | **Understanding Report Page 2** The magnitude of the force vector and the error signals are displayed in the Graphs tab of the Report.\\ \\ {{: | + | ==== Understanding Report Page 2 ==== |
- | **Understanding Report Page 3** | + | The magnitude of the force vector and the error signals are displayed in the Graphs tab of the Report.\\ \\ {{: |
+ | |||
+ | ====Understanding Report Page 3==== | ||
+ | |||
The third page of the report has six graphs. The first graph is the CalTester Segment Residual Graph. This graph shows the residual of the whole CalTester Segment during the trials that were used.\\ \\ {{: | The third page of the report has six graphs. The first graph is the CalTester Segment Residual Graph. This graph shows the residual of the whole CalTester Segment during the trials that were used.\\ \\ {{: | ||
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* If you wish to save the output you can click on the Export to text button at the bottom left of the results dialogue box. | * If you wish to save the output you can click on the Export to text button at the bottom left of the results dialogue box. | ||
- | A sample of the output that should be created is provided below: | + | A sample of the output |
- | Output for force platform 1 : | + | |
**Corrected Locations (in mm):** | **Corrected Locations (in mm):** |
caltester/caltester_mode_overview.1722525390.txt.gz · Last modified: 2024/08/01 15:16 by wikisysop