Differences

This shows you the differences between two versions of the page.

--- caltester:caltester_mode_overview [2024/08/01 15:26] – [Error Report] wikisysop
+++ caltester:caltester_mode_overview [2025/03/31 17:22] (current) – wikisysop
@@ Line 5: / Line 5: @@
 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 stand-alone application. The new application is simply the CalTester tab in Visual3D all by itself.
+**UPDATE:** The standalone CalTester-Plus software application has been discontinued and replaced with a newer CalTester module, which is simply the CalTester tab in Visual3D.
 As a reminder, always go to the CalTester tab first, before opening any CalTester related data files.
@@ Line 13: / Line 13: @@
 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:Documentation:Pipeline:Force_Commands:Modify_Force_Platform_Parameters|force platform parameters]]. Any errors in the parameter settings or calibration measurements will lead to incorrect values of kinetic calculations that rely on the force data.
-{{:CalTesterFigureSmall.jpg}} {{:CalTesterResults.gif}}
+{{:CalTesterFigureSmall.jpg?250px}} {{:CalTesterResults.gif?250px}}
 CalTester is an essential tool for laboratories that:
@@ Line 27: / Line 27: @@
 Functionality is based on recording the position and orientation of a standard commercially available precision mechanical testing device [[CalTester:Documentation:MTD3|MTD-2 CalTester Rod]] via the motion capture system. Implementation of the CalTester functionality was based on the following articles:
-     **The design of the [[CalTester:Documentation:MTD3|MTD2]] device allows a force to be applied to the surface of the force platform without any applied moment.**
+==== The design of the MTD2 device allows a force to be applied to the surface of the force platform without any applied moment.====
-The [[CalTester:Documentation:MTD3|MTD-2 rod]] is a rigid, machined rod with a conical (pointed) tip at each end is used together with a handle and a test plate, each with machined conical depressions. Five tracking targets are attached to the testing rod using rigid posts. Data are sampled simultaneously from the force platform (FP) and the cameras, as forces are applied through the rod to the force platform. The Mechanical Testing Device (MTD-2) is manufactured and supported by [[http://www.motion-labs.com/|Motion Lab Systems, Inc.]] The MTD-2 is a precision-machined calibration-testing tool that can be assembled in less than a minute to create a calibration-testing object suitable for a number of 3D biomechanics laboratory tests. (NOTE: There is an MTD-3 rod that supports adding a load cell on it, and the rods are the same size and work equally well. The MTD-3 may replace the MTD-2.)\\ \\ The following graphics are from the [[https://www.has-motion.com/download/CalTester/CalTesterArticle2003.pdf|CalTester Paper]] Holden JP, Selbie WS, Stanhope SJ, "A proposed test to support the clinical movement analysis laboratory".\\ \\ {{:Fig1CalTesterArticle.png}}\\ \\ {{:Fig2CalTesterArticle.png}}
+The [[CalTester:Documentation:MTD3|MTD-2 rod]] is a rigid, machined rod with a conical (pointed) tip at each end is used together with a handle and a test plate, each with machined conical depressions. Five tracking targets are attached to the testing rod using rigid posts. Data are sampled simultaneously from the force platform (FP) and the cameras, as forces are applied through the rod to the force platform. The Mechanical Testing Device (MTD-2) is manufactured and supported by [[https://mocapmarkers.myshopify.com/|Sisco Mocap]] The MTD-2 is a precision-machined calibration-testing tool that can be assembled in less than a minute to create a calibration-testing object suitable for a number of 3D biomechanics laboratory tests. (NOTE: There is an MTD-3 rod that supports adding a load cell on it, and the rods are the same size and work equally well. The MTD-3 may replace the MTD-2.)\\ \\ The following graphics are from the [[https://www.has-motion.com/download/CalTester/CalTesterArticle2003.pdf|CalTester Paper]] Holden JP, Selbie WS, Stanhope SJ, "A proposed test to support the clinical movement analysis laboratory".\\ \\ {{:Fig1CalTesterArticle.png}}\\ \\ {{:Fig2CalTesterArticle.png}}
 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://www.has-motion.com/download/CalTester/CalTesterArticle2003.pdf|CalTester Paper]] Holden JP, Selbie WS, Stanhope SJ, "A proposed test to support the clinical movement analysis laboratory".\\ \\ **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:\\ {{:Calc1CalTesterPlusArticle.png}}\\ Thus, r and A are parallel and the test device rod orientation (r) is defined entirely by the vector quantity A that is derived from FP measurements (Fp) and the physical characteristics of the testing device (Fg/2, i.e.the weight of the rod and its center of mass location; in this case, half the rod length).\\ {{:CalTesterPlus_DeltaTheta.jpg}}\\\\ The rod orientation variable ( {{:DeltaTheta.jpg}}) is determined from the dot product of the unit vector along A and the unit vector aligned with the long axis of the rod (r) as determined using the motion capture components.\\ \\ **Section II : Equation for evaluating the static equilibrium assumption**\\ \\ Under 2D dynamic conditions, the following holds:\\ {{:CalTesterPlus_Eq4_v2.jpg}}\\ \\ Rewriting the left-hand side of Eq. (4)\\ {{:CalTesterPlus_Eq5_v2.jpg}}\\ \\ Rearranging Eq. (5), the magnitude of the angular displacement ( {{:Beta.jpg}} ) between vectors r and A due exclusively to the inertial terms can be isolated:\\ \\ {{:CalTesterPlus_Eq6_v2.jpg}}\\ \\ where r is the length of the testing device rod, Icg the moment of inertia of the test device rod about the center of mass location, m the mass of the testing device rod and {{:ThetaDoubleDot.jpg}} is the angular acceleration of the testing device rod relative to an inertial reference frame.\\ \\ CalTesterPlus does not calculate {{:Beta.jpg}} since it operates under the assumption that there is no angular acceleration. For this reason it is important to move the CalTester rod slowly at a constant speed.  |
+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://www.has-motion.com/download/CalTester/CalTesterArticle2003.pdf|CalTester Paper]] Holden JP, Selbie WS, Stanhope SJ, "A proposed test to support the clinical movement analysis laboratory".\\
+====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:\\ {{:Calc1CalTesterPlusArticle.png}}\\ Thus, r and A are parallel and the test device rod orientation (r) is defined entirely by the vector quantity A that is derived from FP measurements (Fp) and the physical characteristics of the testing device (Fg/2, i.e.the weight of the rod and its center of mass location; in this case, half the rod length).\\ {{:CalTesterPlus_DeltaTheta.jpg}}\\ \\ The rod orientation variable ( {{:DeltaTheta.jpg}}) is determined from the dot product of the unit vector along A and the unit vector aligned with the long axis of the rod (r) as determined using the motion capture components.\\ \\ **Section II : Equation for evaluating the static equilibrium assumption**\\ \\ Under 2D dynamic conditions, the following holds:\\ {{:CalTesterPlus_Eq4_v2.jpg}}\\ \\ Rewriting the left-hand side of Eq. (4)\\ {{:20140107212337caltesterplus_eq5_v2.jpg}}\\ \\ Rearranging Eq. (5), the magnitude of the angular displacement ( {{:Beta.jpg}} ) between vectors r and A due exclusively to the inertial terms can be isolated:\\ \\ {{:CalTesterPlus_Eq6_v2.jpg}}\\ \\ where r is the length of the testing device rod, Icg the moment of inertia of the test device rod about the center of mass location, m the mass of the testing device rod and {{:ThetaDoubleDot.jpg}} is the angular acceleration of the testing device rod relative to an inertial reference frame.\\ \\ CalTesterPlus does not calculate {{:Beta.jpg}} since it operates under the assumption that there is no angular acceleration. For this reason it is important to move the CalTester rod slowly at a constant speed.  |
      **Estimate the position and orientation of a force platform, instrumented treadmill, or instrumented stair that minimizes these errors..**
@@ Line 42: / Line 46: @@
 Force Platform signals are computed in compliance with [[http://www.c3d.org|the C3D File Format]]
-     **About [[Visual3D:Documentation:Kinematics_and_Kinetics:External_Forces:Force_Overview|Force Platform Parameters]].**
+** About [[Visual3D:Documentation:Kinematics_and_Kinetics:External_Forces:Force_Overview|Force Platform Parameters]].**
 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:Documentation:Kinematics_and_Kinetics:External_Forces:Force_Representation|force signal]] comprising a Force Vector, a Center of Pressure, and a Free Moment applied to the platform.\\ \\ The set of parameters, and how they are used in the computations are unique to each manufacturer. The user should refer to the force platform documentation to identify the correct parameters. These parameters are typically stored in the [[Visual3D:Documentation:Kinematics_and_Kinetics:External_Forces:Force_Platforms#C3D_Parameters|c3d file]] alongside the signals.\\ \\ For calculations involving the interaction of an object/person in the motion capture volume and the force platform, it is necessary to establish the location of the force platform in the laboratory, so that the [[https://www.c-motion.com/v3dwiki/index.php/Transform_from_FCS_to_LCS%7Cforces|can be transformed into the motion capture volume]].\\ \\ In most cases the errors identified in the CalTester report are a result of determining the position and orientation of the platform in the motion capture volume, and not in errors from the platform sensors directly.
@@ Line 49: / Line 54: @@
 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; this is because there is only one Marker Labels tab for all trials. For example if the top-left target on the CalTester is labeled #1 for one trial and #5 for another, then it is guaranteed that the program's results will be incorrect. Mislabeling issue can occur during "noisy" data collection trials, and it is the user's responsibility to ensure all targets have a consistent labeling scheme.\\ * That the axial direction of a lab coordinate system within the c3d files is is a positive x, y, or z direction. It is from one of those directions that the thickness of the caltester test plate is subtracted. This application is usually able to determine which of those 3 directions it is, but a negative axis direction will likely locate the force platform origin a minute amount above its actual location.
+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; this is because there is only one Marker Labels tab for all trials. For example if the top-left target on the CalTester is labeled #1 for one trial and #5 for another, then it is guaranteed that the program's results will be incorrect. Mislabeling issue can occur during "noisy" data collection trials, and it is the user's responsibility to ensure all targets have a consistent labeling scheme.
+  * That the axial direction of a lab coordinate system within the c3d files is is a positive x, y, or z direction. It is from one of those directions that the thickness of the caltester test plate is subtracted. This application is usually able to determine which of those 3 directions it is, but a negative axis direction will likely locate the force platform origin a minute amount above its actual location.
 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:CalTesterPlus:Hardware#Base_Plate|CalTester base plate]] on the force platform.\\ - Zero the force platform so that it will not record the force produced by the CalTester base.\\ - Begin the data capture with the [[CalTester:CalTesterPlus:Hardware#Rod_and_Markers|CalTester Rod]] not in contact with the force platform.\\ - After a second place the CalTester Rod in one of the CalTester base platform's divots, from this point on the CalTester should be the only thing that comes in contact with the force 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't slide between the force platform and the CalTester rod.\\ - 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.
+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)**
+  * Each example motion trial that is downloaded with the CalTesterPlus program meets these criteria.
-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:CalTesterPlus:Hardware#Base_Plate|CalTester base plate]] on the force platform before you begin the collecting the trial.\\ - Zero the force platform so that it will not record the force produced by the CalTester base.\\ - Begin the trial with the [[CalTester:CalTesterPlus:Hardware#Rod_and_Markers|CalTester Rod]] **OFF** the force platform.\\ - After a second place the CalTester Rod in one of the CalTester base platform's divots, from this point on the CalTester should be the only thing that comes in contact with the force 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.
+  * 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:CalTesterPlus:Hardware#Base_Plate|CalTester base plate]] on the force platform.
+  * Zero the force platform so that it will not record the force produced by the CalTester base.
+  * Begin the data capture with the [[CalTester:CalTesterPlus:Hardware#Rod_and_Markers|CalTester Rod]] not in contact with the force platform.
+  * After a second place the CalTester Rod in one of the CalTester base platform's divots, from this point on the CalTester should be the only thing that comes in contact with the force 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't slide between the force platform and the CalTester rod.
+    * 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:CalTesterPlus:Hardware#Base_Plate|CalTester base plate]] on the force platform before you begin the collecting the trial.
+  * Zero the force platform so that it will not record the force produced by the CalTester base.
+  * Begin the trial with the [[CalTester:CalTesterPlus:Hardware#Rod_and_Markers|CalTester Rod]] **OFF** the force platform.
+  * After a second place the CalTester Rod in one of the CalTester base platform's divots, from this point on the CalTester should be the only thing that comes in contact with the force 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 =====
-     Tool Bar{{:V3DCalTesterToolBar.png}}                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            {{:V3DCalTesterPage1.png}} **View CalTester Report Summary Page 1** - This button helps to control the right side of the screen. When selected, the right side of the screen displays page 1 of the CalTester report, which contains a summary of the full report.\\ \\ {{:V3DCalTesterPage2.png}} **View CalTester Report Graphs Page 2** - This button helps to control the right side of the screen. When selected, the right side of the screen displays page 2 of the CalTester report, which contains graphs for the Ground Reaction Force Magnitude, the CoP Error (X, Y & Z), and the CalTester Rod Orientation Error.\\ \\ {{:V3DCalTesterPage3.png}} **View CalTester Report Graphs Page 3** - This button helps to control the right side of the screen. When selected, the right side of the screen displays page 3 of the CalTester report, which contains graphs for the CalTester Segment Residual, and Marker Residuals (Top Left, Top Right, Middle Left, Bottom Left, and Bottom Right).\\ \\ {{:V3DCalTesterZoomIn.png}} **Zoom in on the report** - This button allows the user to zoom in on the page of the report that is shown on the right side of the screen.\\ \\ {{:V3DCalTesterZoomOut.png}} **Zoom out of the report** - This button allows the user to zoom out on the page of the report that is shown on the right side of the screen.\\ \\ {{:V3DCalTesterRodDimensions.png}} **Modify CalTester Rod Dimensions** - This button opens the Rod Dimensions dialogue box. Further details on the function of the dialogue box can be found [[CalTester:Documentation:Rod_Dimensions|here]].\\ \\ {{:V3DCalTesterPlatformParameters.png}} **Modify Force Platform Parameters** - This button opens the Modify Force Platform Parameters dialogue box. Further details on the function of the dialogue box can be found [[CalTester:Documentation:Modify_Force_Platform_Parameters|here]].\\ \\ {{:V3DCalTesterForceStructure.png}} **Modify Force Structures** - This button opens the Modify Force Structure Parameters dialogue box. Further details on the function of the dialogue box can be found [[CalTester:Documentation:Tab_Force_Structure|here]].\\ \\ {{:V3DCalTesterPlatformLocator.png}} **Force Platform Locator** - This button opens the Force Plate Location dialogue box. Further details on the function of the dialogue box can be found [[CalTester:Documentation:Tab_Platform_Locator|here]].
+Tool Bar{{:V3DCalTesterToolBar.png}}
+{{:V3DCalTesterPage1.png}} **View CalTester Report Summary Page 1** - This button helps to control the right side of the screen. When selected, the right side of the screen displays page 1 of the CalTester report, which contains a summary of the full report.\\ \\ {{:V3DCalTesterPage2.png}} **View CalTester Report Graphs Page 2** - This button helps to control the right side of the screen. When selected, the right side of the screen displays page 2 of the CalTester report, which contains graphs for the Ground Reaction Force Magnitude, the CoP Error (X, Y & Z), and the CalTester Rod Orientation Error.\\ \\ {{:V3DCalTesterPage3.png}} **View CalTester Report Graphs Page 3** - This button helps to control the right side of the screen. When selected, the right side of the screen displays page 3 of the CalTester report, which contains graphs for the CalTester Segment Residual, and Marker Residuals (Top Left, Top Right, Middle Left, Bottom Left, and Bottom Right).\\ \\ {{:V3DCalTesterZoomIn.png}} **Zoom in on the report** - This button allows the user to zoom in on the page of the report that is shown on the right side of the screen.\\ \\ {{:V3DCalTesterZoomOut.png}} **Zoom out of the report** - This button allows the user to zoom out on the page of the report that is shown on the right side of the screen.\\ \\ {{:V3DCalTesterRodDimensions.png}} **Modify CalTester Rod Dimensions** - This button opens the Rod Dimensions dialogue box. Further details on the function of the dialogue box can be found [[CalTester:Documentation:Rod_Dimensions|here]].\\ \\ {{:V3DCalTesterPlatformParameters.png}} **Modify Force Platform Parameters** - This button opens the Modify Force Platform Parameters dialogue box. Further details on the function of the dialogue box can be found [[CalTester:Documentation:Modify_Force_Platform_Parameters|here]].\\ \\ {{:V3DCalTesterForceStructure.png}} **Modify Force Structures** - This button opens the Modify Force Structure Parameters dialogue box. Further details on the function of the dialogue box can be found [[CalTester:Documentation:Tab_Force_Structure|here]].\\ \\ {{:V3DCalTesterPlatformLocator.png}} **Force Platform Locator** - This button opens the Force Plate Location dialogue box. Further details on the function of the dialogue box can be found [[CalTester:Documentation:Tab_Platform_Locator|here]].
 ===== Error Report =====