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Gait analysis force calculation at the joints
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Can you cite me to a paper or book that will help me carry out the procedure.
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Till now, I have only processed single baseline (One base - one rover) in RTKLIB in Kinematic or DGNSS mode. Can I process multiple baselines (e.g. One base - two rover) in RTKLIB? If so how can I do that?
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Bigyan Banjara Stallin Bhandari Sandesh Upadhyaya Could you please help me on this :)?
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How can I process the raw kinematic biomechanics data? For example, how can I process the C3D files exported from VICON to obtain usable, accurate kinematic and kinetic data? Do you have any book recommendations?
I am new to the subject, thank you all!
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Hello Chou Wu,
As far as I am concerned, the easiest way is to use the btk biomechanical toolbox. You will find it quite easily on internet.
Then, you will have to choose a way to process from raw data.
The ISB recommandations are of interest to read to ease processing / help to determine markers position.
1. Wu, G. et al. ISB recommendation on definitions of joint coordinate systems of various joints for the reporting of human joint motion—Part II: Shoulder, elbow, wrist and hand. J. Biomech. 2005, 38, 981–992. https://doi.org/10.1016/j.jbiomech.2004.05.042.
2. Wu, G. et al. ISB recommendation on definitions of joint coordinate system of various joints for the reporting of human joint motion–part I: Ankle, hip, and spine. International Society of Biomechanics. J. Biomech. 2002, 35, 543–548.
3. Wu, G.; Cavanagh, P.R. ISB recommandations for standardization in the reporting of kinematic data. J. Biomech. 1995, 28, 1257–1261..
Then, you can directly create segmental and joint frames bases on markers (not for all joints such as hip), or you could use musculoskeletal models to ease processing, such as with OpenSim ou Anybody.
I hope this helped.
Regards
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I'm planning to do a study on the kinematics of rigid bodies. But I don't know a program where I can draw the shapes that I intend to use in this study.
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Also Blender for 3d modeling. It is free and resourceful.
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Dear RG members,
I am working on finding the links between joint kinematic and EMG time series in pathological gait cycles.
The objective is to try to explain altered kinematics from altered EMG.
Do you know of any methodologies to explore that?
Do you think I need a healthy group to study the differences in kinematics and EMG?
Thank you very much for your responses.
Kind regards,
FrEd
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Dear Frédéric,
I believe that you'll need a healthy group to study the differences in kinematics and EMG, thus in order to have a reference group (here for instance the healthy one) if you should not find any value in the literature referencing normal value for the healthy patient. I also think that you could take the first value as a reference for the patients with altered gait cycles and then after treatment retest and see how the patient has improved compared to his or her initial value. I send you an article from Lencioni et al.(2019) which might be of interest to your research.
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Hello
Can I ask for a raw data for normal Gait Kinematics and kinetics that can be added to Excel sheet ?
Thanks in advance, your cooperation is highly appreciated.
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to my knowledge, this is the most comprehensive published data set treating gait:
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Hello Everyone, I am working on 3 DOF parallel manipulator.
I was trying to find the reachable workspace of my parallel manipulator by the Monte Carlo method, and I am facing an error to solve it.
I created a MATLAB script to find workspace by Monte Carlo Simulation Method, the output of the script generates random position coordinates which the centroid of the end effector can reach with at least one orientation.
After generating random coordinates, I was easily able to solve the inverse kinematics by selecting a random coordinate generated by Monte Carlo, but when I tried to solve the forward kinematics, I was not able to get the same position coordinates that I used to solve the inverse kinematics.
Also, when I tried to manually change the leg lengths of my parallel robot in SolidWorks according to the output of inverse kinematics, I was not getting the same position coordinates of the end effector, as the values, I used to solve the inverse kinematics.
Note:
(For Inverse Kinematics Input: randomly generated position coordinate; Output: leg lengths)
(For Forward Kinematics Input: leg lengths obtained from inverse solution; Output: position coordinate of end effector)
I don't know where I am going wrong, Can anyone please help me with this?
Thank you in advance, I really appreciate your help !!
Shiv
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Shiv Karpoor take a look at this article:
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I have a set of joint kinematics, collected via 3D mocap. I do not have any corresponding GRF/GRM data. Is there a way to calculate the GRF/GRMs from the kinematic data? I've seen some published work doing this, but the math is a bit above my head. Has anyone published any code etc in which you can plug in some kinematic data and it auto-generates the GRF/GRM for you? Alternatively - can anyone please advise an easy to follow method to calculate GRFs?
Thanks in advance!
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Ashleigh Wiseman you are absolutely right, the part about a ready-to-use solution on my previous answer was misleading. AnyBody can estimate GRFs from MoCap data (I don't really know about MOCO) in a similar fashion to what i described. It really depends though on what type of activity you are recording and the level of accuracy you need in your predictions. I also expect that full bod mocap would return more accurate results.
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Dear all ,
I wanted to ask with an example , let us say , we modeling a CT specimen with XFEM , I wanted to ask what is the difference of specifying kinematic coupling between the pins and hole and giving say displacement (as in displacement control) to the pins to giving displacement to the nodes at the hole directly ? What is the difference between both the cases ?
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FEM is the conventional finite element method traditionally been implemented in commercial software like ABAQUS and used for most of the quasi-static and dynamic analysis without crack in the geometry whereas ,XFEM (short for, eXtended Finite Element Method) is used to simulate problems involving a pre-existing crack in the geometry and in the background it enriches the solution space of conventional FEM. I hope it answer yours question sir .
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Is there any mathematical way/method to calculate GRF from kinematic data?
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Firstly you should calculate the equation at the centre of mass. And you can using reduction techniques in determinate system to reduce unknowns. exp: neglecting some parameters or some muscles.
Then using Newton laws to calculate forces and moment.
Consider summation of forces in the horizontal an vertical direction separately including GRF and external forces equal to m x a.
Finally consider summation of moments in centre of mass equal to mass moment of inertia x angular acceleration.
By solving these 3 equations by putting knowns, the unknown parameters are calculated.
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We want to build a reach task with as few elements as possible...
We have a nice workshop and also a 3D printer
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You can dimension your workspace by lengths of both links R,r. You get a workspace limited by two (semi)circles of inner radius R-r and outer radius R+r then.
Extending the two links by a parallelogram (shown on the right) you will yield the same kinematic behaviour (DoF = 2) ... probably the mechanism shown in your image, I believe now. Advantage would be higher stiffness ... but you asked for minimal link number, which would be two.
You have only revolute (rotational) joints similar to those shown in your picture.
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Error : The ratio of deformation speed to wave speed exceeds 1.0000 in at least one element. This usually indicates an error with the model definition. Additional diagnostic information may be found in the message file.
Abaqus/Explicit Analysis exited with an error - Please see the status file for possible error messages if the file exists.
Warnings: The option *boundary,type=displacement has been used; check status file between steps for warnings on any jumps prescribed across the steps in displacement values of translational dof. For rotational dof make sure that there are no such jumps. All jumps in displacements across steps are ignored
There are 42 warning messages in the data (.dat) file. Please check the data file for possible errors in the input file.
Boundary conditions are defined at the nodes contained in node set WarnNodeBcIntersectKinCon. In addition the nodes are also part of a surface involved in kinematic contact. The kinematic contact constraint will be overridden by the boundary conditions in case of a conflict. Penalty contact may be used instead.
The nodes in node set WarnNodeCnsIntersectKinC are part of a kinematic contact surface definition as well as participate in a kinematic constraint (or distributing coupling). Nodes that participate in a kinematic constraint definition should not be used in a kinematic contact surface definition. If a degree-of-freedom participates in both types of constraints, the kinematic contact constraint will most often override the kinematic constraint. Abaqus/Explicit will not prevent the user from defining these conditions, but the resul
The ratio of deformation speed to wave speed in the elements in element set WarnElemDeformRateExceedsRatio-Step1 exceed the warning ratio. Refer to the status file for further details. This message is printed during the first applicable increment, but will not be printed during subsequent increments for the remainder of the step.
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You converted it wrongly.
The density of water is close to1000 kg/m3
I'm pretty certain you should be using SI units, which are kg/m3.
That is almost certainly what the other parameters are based on.
Whatever your table tells you tonne/mm3 is not the SI unit of density.
If you do use that then you will need to change the values of all your other inputs such as Youngs modulus and yield strength to be in terms of tonnes and mm.
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I have exported an Abaqus model as a .bdf file and then opened it in Nastran. Beams, bushings and kinematic couplings that I had defined in the Abaqus model did not get translated into Nastran. All other details, mesh, boundary conditions, loads, step definitions were translated.
Is there anyway I can translate these 1D elements as well.
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Hi
Beams tend to have different definitions between FE software.
To translate any cross section shape, you would have to use generic data, ie Inertias etc rather than dimensional data.
/C
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I have collected oriented samples of deformed dykes (bearing schistosity and c/s structures, etc). I have sawn three slabs of each sample orthogonal to each other (xy, xz, and zy planes). On each slab I should be able to measure the movements (sense of slip). Now, I would like to have the resulting three main kinematic axes for this sample. I guess that one way is to draw, on a stereogram, the three planes and their sense of slip and then let the software compute the main axes. Is this correct? I commonly use Faultkin and Stereonet."
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yes. completely correct
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I am looking for study materials about Kinematic chains. Any book or course notes that addresses basic principles and more would be of great help. Thank you!
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I'm working with a motion capture system which tracks body markers during walking. This system assignes zero value to markers displacement when it couldn't track them (i.e zero to missing value like figure rawdats).
when I used fourth order zero lag butterworth filter for smoothing, the regions of interest and some parts of the signal changed
I tried converting all zeros to nans (figure nans)and then interpolating the signal but this doesn't work because at the beginng of the aquistion signal is nan which makes the result signal messed.
How can I fill these missing data (interpolate signal with missing data) or smoothing the signal without losing regions of interest
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Dear Rufaida, the signal pattern you have shown is quite similar to the pupil diameter when an eye blink occurs. Based on that, a cubic spline interpolation as an imputation technique might be a good approach!
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I need the basics for including energy loss in Hamilton formulation for Finite element analysis for vibration of viscoelastic materials. The papers I read use complex modulus to represent viscoelastic losses or convolution integrals. Can someone give me a link where the formulation starts from Hamilton's principle?
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Have you got answer about it?
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I am working on a goalkeeper goalkeeper research which is developing the kinetic response speed of a goalkeeper goalkeeper and I need a standardized test that measures this trait or maybe an electronic device that measures the same trait
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I don't know a standardized test that measures response speed. However, there are a large number of computerized tests that evaluate the speed of motor response in milliseconds, which could be a convenient measure for what you intend to do, since you can compare the response before and after training.
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Assume this as a beam with a horizontal force acting on top of it. The structure is hinged to a fixed plate with springs on both sides. How do I calculate the forces F2 and F3 based on the known F1 values?
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If all elements were rigid, the value of the forces I provide is valid.
If they were not rigid (we know we have no rigid body in real life), part of the F1 force might be absorbed by the flexibility of the elements and the equation I provide is no longer valid (this statement depends on the stiffness of the springs, if the stiffness of spring were too weak, approximately no force would be absorbed by the elements).
Since it is an experimental test, I recommend collaborating with a civil engineer in your lab.
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I am doing thermomehcanical analysis for "Short fiber reinforced plastic" based on the isotropic hardening . As i am doing only the isotropic hardening , i want to ask you
a) which hardening effects more on the results either isotropic hardneing or kinematic harening ?
b) How much isotropic hardening effects (for example in %) and how much kinematic hardening contribute in the result and which one is more important.?
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very interesting and it may depend on the tensile properties of the fibres.
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I am simulating a sheet metal forming process (Deformable Vs Deformable). Incorporating anisotropic elastic properties would need 21 constants. To make simulation easier, can isotropic elastic constants be used with Hill's yield criteria and kinematic hardening to mimick anisotropy and cold working?
Note: 3D FEA model
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Tusar Mohanty If your are not so familiar with Hill48, can check this video:
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I know it is a very basic question but we have tried many times and are getting different values so for the confirmation I am posting here.
F is the Faraday constant (96,485 C mol-1 ). C0 is the bulk concentration of O2 (1.2 × 10-6 mol cm-3 ). D0 is the diffusion coefficient of O2 in 0.1 M KOH (1.9 × 10-5 cm2 s -1 ). ν is the kinematic viscosity of the electrolyte (0.01 cm2 s -1 ). k is the electron transfer rate constant and adopts 0.2 when ω is expressed in rpm.)
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I think you will find your answer in this paper and if you need more you can check the references as well
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To develop constitutive models in continuum mechanics, one must consider kinematics, balance of momentum, balance of energy, and free-energy imbalance. Next, one must propose constitutive response functions that express dependent variables (e.g., free energy, stress, entropy, flux, and chemical potential) as functions of independent variables (e.g., deformation gradient, temperature, temperature gradient, and concentration of species). So, what are the general principles to determine which variables are dependent variables and which are independent variables?
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Hello, Jin Yang, thank you for your helpful comments. I agree with you on both ends. Below are my thoughts.
It is a great idea to treat conjugate variables as dependent variables. This strategy appears to work well even if a problem has no convenient variational forms, in which case the free-energy imbalance can still provide sets of conjugate variables. For instance, guided by the free-energy imbalance, entropy is conjugate to temperature, stress is conjugate to strain, heat flux is conjugate to temperature gradient, chemical potential is conjugate to species concentration, etc.
It is also very helpful to use the number of governing PDEs to identify the number of unknown, or independent, variables. Then, constitutive laws can be treated as additional equations that serve to close the system—any remaining quantities that are NOT independent variables should be expressed as functions of those independent ones.
After applying these principles, one may be already a long way toward identifying independent and dependent variables. For many problems, however, this kind of classification is non-unique. This is because some variables can be written in terms of each other by simply inverting the related functions, thus interchanging the role of independent and dependent variables. Which choice is most convenient really depends on conditions of interest; for those cases, it might be hard to articulate a general guiding principle—one has to bring in intuitions in physics.
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I am confused with co-efficient of friction and friction factor.
A part of a Fluid Mechanics text book says that in Darcy-Weisbach equation
hf=(f L V2)/(2g D)
f is friction factor.
In the same time, it says that in below equation the f is co-efficient of fraction.
hf=(4f L V2)/(2g D).
In this case, we see that (Friction factor = 4 x co-efficient of friction).
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Does anyone know the exact name of the following equation used for friction factor calculation?
f=16/Rek
1/√f= G log (Rek√f)-H
that G, H, k are constants that have different values.
what dose the index of k shows?
i want to know how i should choose the correct value for each constant
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INS-RTK modules claim to be close to a cm accuracy, has anyone used one and if so, how expensive can the telematic charges be if I have a case to run it 18h per day?
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Dear Mani Entezami, we have used for our studies the Leica Zeno GG04 plus Smart Antenna (RTK-based but without INS) and XSens MTi-680G (RTK and INS-enabled). Both reach cm accuracy. As network RTK service we use HxGN SmartNet. You can buy hour packages or unlimited access. For GB you find prices here: https://hxgnsmartnet.com/en-gb/services/network-rtk
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What is the best platform for implementing inverse kinematics of a 6-axis robotic arm? I have a robot parts with Nanotec controllers. But there is a lack of information or literature how to control the Nanotec controllers. I'm not an expert in robotics. The task is a part of a project. So it will be good if there are already existing solutions, as there is no reason in reinventing a bicycle.
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Thank you for the information. It is very helpful.
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I would need kinematic data related to the full arm (and not focused on the hand, such as NinaPro dataset). Thanks to anyone who can help me!
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I would like to linearize my nonlinear MIMO system (I use this model for reference tracking purposes), but it doesn't fulfill the requirement of feedback linearization. Are there any alternative methods to linearize this system?
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I am doing frequency analysis of an orthotropic bridge. To connect the girder with girder, floor beams and edge beams, I assigned MPC constraints to the respective nodes. But after running the analysis, I am getting the following error:
"22 nodes are missing degree of freedoms. The MPC/Equation/kinematic coupling constraints can not be formed. The nodes have been identified in node set ErrNodeMissingDofConstrDef."
I checked again the constraints, but there was not any node with missing dof.
Anyone can suggest me solution? It will be appreciated.
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Perhaps you have assigned two MPCs to the same node of your shell member. Try to use only one MPC.
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The Coriolis matrix S(q,q') in the Lagrangian formulation is a coupled n*1 matrix. But in many mathematical models, an n*n Coriolis matrix S(q,q') multiplied by q' is used. I need to understand how to transform the former into later. Also, are the q and q' values in the matrix, the desired values, or the instantaneous values?
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I have summarized the answer in a pdf file, so you have some mathematical passages that I hope will be helpful.
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A kinematic equation that is asking for (1) What could be the highest height the solid object can reach. (2) How long does it take for the object to reach the ground. With the application of Calculus.
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You're welcome Rhea Mea Impas, I am glad that I was able to help...
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I am searching the web for "Thrustpack" modeling software but haven't come across it. Is it open access? Are there any alternative open-access codes for forward kinematic modeling of thrust belts?
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Hi There! You should try the Andino, one of the most powerful modeling softwares, and it is available in full for free academic use,
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What is the principle of RTK (Real Time Kinematic) in the using GPS in topographic and bathymetric survey?
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In bathymetric survey, it is a combination between GPS-RTK coordinates for a such reference datum in the measurement ship and connected to an Echo sounder to estimate the depth of the water related to the same datum. then you get a sheet of coordinates with bed levels.
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It is a Kinematics in one dimensional motion. Asking for average velocity in meter per second squared and in multiples of gravity which is 9.80m/s².
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Dear Dr. Impas,
I apologize if I did not understand the question correctly .
In one-dimensional movements maybe the resolution is:
a = ∆v / ∆t = 6500/60
a = 108.333 m/s² , where "a" is the average resultant acceleration produced by engine propulsion.
The vertical displacement of the missile can be calculated with the equation:
S = So + Vo.t + 1/2 . a . t² , So = 0, Vo = 0
S = 1/2 . 108.3 . 60² = 195 000 m (195 Km)
The acceleration of gravity on the equator can be calculated by the law of universal gravitation:
g = G . m / d²
G = 6.67408E-11 m³/kg s² , m = 5.973332E+24 kg ( Earth mass ) ,
d = 6 378 136.6 m. Thus, g = 9.8 m/s²
The acceleration of gravity will decrease at an altitude of 195 000 m:
g = 6.67408E-1 . 5.973332E+24 / (6 378 136.6 + 195 000)² = 9.227 m/s²
I hope this information is useful. Best Regards, Wagner de Godoy
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I have a robotic system that is not actuated in one joint (no torque is applied) and actuated in all other joints.
In this model, the blue rectangles are the links of the robot, the filled small circles are the joints and the circle slot is a constraint that the slider is rotating around it. The red filled circle and the red slot are connected to the ground but the red filled circle is a motor that produces torque. Among other joints, 2 of them are actuated and one is just a joint and isn't actuated.
The slider is applying force to the circular slot to remain on the track. This constraint force consists of a force toward the center of the slot and a moment in the direction perpendicular to the figure.
I want to solve the forward dynamics (by having the joint torques, I want to obtain all link's angular accelerations) to convert it into a state-space form. It is preferable for me to be able to obtain the constraint forces in the slider, also. I don't want to use ordinary newton's method. What other methods do you recommend me to use and why? Please remember that this system is a closed-lop kinematic chain and not a tree-structure (serial kinematic structure). I will be grateful if you introduce good references for the method you recommend.
Thanks
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Dear
Siamak Heidarzadeh
Thanks for your comprehensive response. It was very helpful.
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Dear motion analysis experts
I have some motion data that contain double support jumping kinematics.
at the time that I took the test, I didn't know that I have to use 1 force plates for each leg. so my cases jumped on a force plate with both foots.
I used vicon software to calculate kinetic data for demonstrated side.
Is it logical?
if not, what should I do to calculate joints kinetic?
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yes... by considering a symmetrical jump, knee kinematic differences between 2 different group was significant.. so its not true if we compare kinematic data in this case?
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Hi guys! I am recently reading Nonlinear Solid Mechanics A Continuum Approach for Engineering by Gerhard A. Holzapfel, Chapter 2.3 and was confused with one equation. You can refer to this stackexchange link for more detail (https://physics.stackexchange.com/questions/558789/why-the-material-time-derivative-of-a-material-field-f-equals-to-the-direction). In short, this equation states that the the material time derivative of a material field 𝐹 equals to the directional derivative of 𝐹 in the direction of the velocity vector 𝑣. I tried to prove this equation but failed and the process has been attached in the stackexchange post. Can someone help me with this?
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regarding the 3 first words:
1. "for some studies",
2. "in this text",
3. "we introduce",
we cant deduce with safety & abstractly the assertion about the equality of the material & directional derivative and besides this, the mentioned "Gâteaux Operator" is the (?):
Gâteaux Differential, with linearity & continuity conditions or
Gâteaux Variation a weaker version of the GD, without the demand of the linearity & continuity but with the homogeneity.
Therefore:
1 GO ∈ {GD,GV} (logically GO = GV),
2 GDGV (generally the converse doesn't hold).
The solution for this misunderstanding is:
• let a t-independent (static) tensor field T = T(x), cause of the 1-dimensionality / "scaleness(*)" of the time,
• demonstrated through the 3 below parts
(Intro., 3-Calc., 3-Comp.).
(*): There are some interesting cases which the time notion is not a scalar but inherently-anisotropically a 2-adic quantity (2nd order tensor) as a characteristic time or weight for some differential operators, such as the one of the Lord-Shulman model:
Lt = I + τ0t= or tLij = δij + 0τij t.
Introduction
A. Let the index of the:=
(1) tensor order τ ∈ ℕ ⊔ {0},.s
(2) dimension δ ∈ ℕ,
the hyperreal number ε ∈ ℝ, |ε| ≪ 1,
and the product P of the non-homogenous dimension (δi δj):
P = Πτ ∈ ℕ(δτ) = δ1 × δ2 × ... × δτ × ... .
B. Let the differential operators:
(10) gradient or x-partial derivative: ∇ ≡ ∂x ≡ ∂/∂x,
(11) right gradient: {○}⊗∇ ≡ ∇{○},
(12) left gradient: ∇⊗{○} ≡ (∇{○})T,
(2) rate or t-partial derivative: {○} ≡ ∂t ≡ ∂/∂t,
(31) material-total t-derivative: {○}■m ≡ dt ≡ d/dt,
(32) conservative-total t-derivative: {○}■c ≡ Dt ≡ D/Dt
(4) directional derivative (along the vector v):
v{○(x,t)} = ∇{○(x,t)} • v
≡ d{○(x + εv,t)}/dε|ε=0 ≡ dε{○(x + εv,t)}|ε=0
(5) convective derivative: ∇{○} • v
Γ. Let the physical/geometrical entities:
(1) xt-pair (x,t) ∈ Ω × I ⊂ ℝ3 × ℝ ≅ ℝ4,
(2) arbitrary-order ℝ-tensor field T:
T: Ω × I → ℝP | (x,t) ↦ T(x,t) = T.
3-Calculation
Α. The material-total t-derivative {○}■m
of the arbitrary-order ℝ-tensor field T = T(x,t) is:
dT(x,t) = (∂T/∂x) • dx + (∂T/∂t) dt
T ■m = ∇T v + T (✓).
Β. The conservative-total t-derivative {○}■c
of the arbitrary-order ℝ-tensor field T = T(x,t) is:
T ■c = T ■m + T (∇ • v) = (T v) • ∇ + T (✓).
Γ. The directional derivative dε{○}|ε=0
of the arbitrary-order ℝ-tensor field T = T(x,t) is:
dT(x + εv,t) = [∂T/∂(x + εv)] • d(x + εv) + (∂T/∂t) dt
dεT(x + εv,t) = [∂T/∂(x + εv)] • v + 0
∴ dεT(x + εv,t)|ε=0 = ∇T v = ∇vT (✓).
3-Comparison
(1) The material- & conservative- total t-derivative {○}■m & {○}■c are equal, iff the convective term is zero:.
∇ • v = 0 ⇔ divergenless/solenoidal field v (*1)
This is also called incompressibility condition, iff v is the velocity field (e.g. in Fluid Mechanics incompressible flows).
(2) The material-total t-derivative {○}■m & directional derivative dε{○}|ε=0 are equal, iff the arbitrary ℝ-tensor field is independent of t: T = T(x) ⇔ static field (*2)
T ■c = T ■m = ∇vT, iff (*1,2) holds. ☐
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I want to convert the Young's modulus and Poisson ratio of an orthotropic material given in Cartesian coordinates into cylindrical coordinates. Please suggest me the way or provide me the link or document where I can get these things. Thanks in advance
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Also note that under the same loading the deformation of material with rectilinear orthotropy differs from the deformation of materials with cylindrical orthotropy.
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I have been contacted by a famous French journalist who wants to interview me for a French radio program (on Sud Radio) about my preprint on the Mamoudou Gassama affair:
Since no scientific journal would accept to publish my preprint because of the political dimension of the affair (involving French President Emmanuel Macron), the journalist would like to find scientists, not closely related to me, who would accept to testify that my analysis is scientifically sound. He is not asking for people to testify that what I suggest is really what happened, but just to testify that my analysis makes sense.
Let me know if you are interested, and I will send you the contact information for sending your testimony.
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My article was reviewed by several scientists, including famous physicist Florence Vives who joined the United Nations. The interview is available here, but it is in French:
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Hi everyone,
I'm trying to setting up a soil property in ANSYS 19.2 student version. I want it to be a Mohr-Coulomb model. But I also want to add a kinematic hardening law to it so that it can caputure the volume change better under cyclic loading.
However, as far as I know, the 'Bilinear Kinematic Hardening' and 'Multilinear Kinematic Hardening' options in 'Engineering Data' are for the metal properties and don't allow any parameter input for the soil kinematic hardening law.
Can anyone help me out?
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Hi, in part of the engineering data, biomechanical part, you can find soil material plasticity behavior, and also you can define additional information from the left column of material characteristic behavior to define your material. additionally, this library has a lot of predefined material properties, of which you can use.
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five-axis industrial robot is being designed for pick and place application. for analysis it i am in need of references
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Nowadays Kinematics is gaining new light in face of many applications which have arised in the world and outer space. Helical transformations, e.g., has given conditions to create a full maintenance robots called RoboTurb. It diagnosis and repairs turbine blades moving in flexible tracks fixed with suction cups. Augmented formulations such as Sheth-Uicker allow one to model parallel robots such as industrial ones already in operation for a decade. Another thing is coding into computer language such as parallel C , Visual C, Borland C or trivial ANSI C. So watever you people are interested in I will be happy to provide information. That is my job. Good luck you all in your research.
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The bionic car which is a concept car is said have an good aerodynamic shape. It having a larger frontal area is cited as a reason.
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Dear Raji,
Frontal area is the area where a car hits the air head on. The total resistance offered by the vehicle is the product of frontal area and drag coefficient. The force exerted by air on anybody moving through it is called Aerodynamic Drag. The bionic car which is a concept car is said have a good aerodynamic shape. It having a larger frontal area is cited as a reason. It is generally accepted that some variation of the teardrop/airfoil shape has the lowest drag coefficient. For speeds lower than the speed of sound, the most aerodynamically efficient shape is the teardrop. The teardrop has a rounded nose that tapers as it moves backward, forming a narrow, yet rounded tail, which gradually brings the air around the object back together instead of creating eddy currents. The aerodynamic efficiency of a car's shape is measured by its co-efficient of drag (generally known as its Cd figure). One can achieve a minimum drag coefficient based on the frontal area if is very less as 0.05, matching that streamlined bodies in free air. If the base area is close in the magnitude of frontal area, drag of the bluff body may be proportional to the frontal area. Product of frontal area and drag coefficient can give the total resistance which is the idea of performance of the aerodynamic vehicle. For example, a flat plate held at right angles to the airflow has a Cd of 1.25, whereas the most efficient production car shapes at the moment have a Cd of about 0.28.
Hope this is quite useful for you.
Ashish
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I am getting higher natural frequency value of a sandwich plate when computed on the basis of HSDT as compared to that of FSDT. But in general it is expected that the higher order kinematics (cubic in-plane displacement) should give lower frequency values than that computed using first order kinematics (linear displacement). I know that my result is correct, but I am unable to justify this point. kindly help
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You may check your report correctly once again.
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I am looking for EMG signals from any trunk muscle specially obtained for fatigue analysis. Isometric contraction. 
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Imran Ahmad , Chao Mi Did anyone of you found the relating Dataset? Or anyone of you have solved this problem then please help.
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I am a bio-mechanic engineer and I want to analyze human different movements like gait and jump.
I had written a code based on Christopher L Vaughan book: dynamic of human gait.
It was good because of calculation of instant center of rotation in joints and it was complicated due to this advantage.
Is there any other useful and detailed reference for calculating joint forces and moments?
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ISB recommendations on the reporting of intersegmental forces and moments during human motion analysis
Journal of Biomechanics - Volume 99, 23 January 2020, 109533
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I am using optitrack motion capture system to calculate the Maximum Lyapunov exponent from kinematic gait data .Different retro reflective markers are placed on trunk and feet of the subjects.
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No clear consensus exists about the best methodology to compute MLE. Regarding motion capture methods, many studies use the C7 or T6 markers to compute trunk velocity. Others use hip/knee/ankle angles. A very good reference to have an overall survey of existing methods is the recent systematic review by Sina Mehdizadeh. Check the supplementary file that gives details about the methodology of each study.
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I m looking for the tool to synthesize the kinematic mechanisms automatically?
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No. There are methods to design mechanical linkage mechanisms, but none are automated.
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A mechanism is moving in a particular pattern. There is a real time video of the same with red color markers are stick to each links. Is there any image processing tool or software which can capture the movement of links and give its change in position, velocity and acceleration? So that the results can be used to co relate rigid body/ multibody dynamic model results.
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Hi Subhash,
You are looking for an object tracker / feature matcher. Here below a few tools I remember of:
1) https://physlets.org/tracker/ -> it's manual, quick and dirty for analysing a small quantity of data.
3) http://www.mousemotorlab.org/deeplabcut -> this tool seems promising enough, but computationally heavy.
Keep it simple if you can.
Best,
Andrea
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In the framework of gravitoelectromagnetism (GEM), a gravitational field is a dual entity always having a “field” component Eg, and an “induction” component Bg simultaneously created by their common sources: time-variable masses and mass flows. By the introduction of the physical quantity Bg the description of gravity in GEM takes the kinematics of the gravitating objects into account what implies that GEM is an extension of the classical field theory of gravity.
In GEM, the phenomenon of the deflection of a light ray passing the sun is explained by the effect of the sun’s gravitational field on the constituent elements of light.
The constituent elements of light, the photons, are moving with velocity c. According to the “force law of GEM”, a photon moving in a gravitational field (Eg, Bg) in general - and in the gravitational field of the sun in particular - will be accelerated with an amount: a = Eg + (c x Bg). The normal component of a causes the bending of the photon’s trajectory.
  1. At an arbitrary point P near the sun, the vector Eg is directed to the center of the sun.
  2. The direction of the vector (c x Bg) at P depends on the direction of c (this is the direction in which the light propagates). If a light ray is passing the sun on one side the direction of c is opposite to the direction of the moving surface of the sun (retrograde), and if a ray is passing the sun on the opposite side the direction of c is the same as the direction of the sun’s moving surface (prograde). In the first case (c x Bg) is directed to the sun, in the second case it is directed away from the sun.
So, in the first case the bending effect of Eg on the light ray is strengthened by the effect of (c x Bg), in the second case it is weakened. If half of the observed deflection of a light ray at one side (first case, retrograde) is the effect of Eg , the deflection of a ray at the other side (second case, prograde) should be negligible. Do this correspond to the observations?
In the above we were looking to the impact on a light ray of the gravitomagnetic effect of the rotation of the sun around its axis. Another source of the sun’s gravitomagnetic induction is its translation. Indeed because the sun, relative to the earth, is moving in the ecliptic with a velocity v it generates a gravitomagnetic field. When Eg is the gravitational field at a point P, it can be shown that the gravitational induction at that point due to the sun's translation can be expressed as: Bg =1/c2.(v x Eg). Note that, also in this case, the orientation relative to Eg of the component (c x Bg) of the acceleration a of a photon passing near the sun, is different depending on the side of the sun where the photon passes. Note also that the component (c xBg) = ec x (v/c x Eg) is very small relative to the component Eg [because of the factor (v/c)].
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Antoine J.H. Acke: "Do this correspond to the observations?"
Is there any idea on how bending of light by the sun according to GEM compares in orders of magnitude to what A. Einstein in 1911 derived by assuming luminal speed c = c0(1+Φ/c2) to depend on local gravitational potential Φ, see references (original German and English translation) below?
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Hi!
I'm trying to approach the inverse kinematics of a robot arm with a non-spherical wrist as an optimization problem, as a closed-form solution is extremely hard(or sometimes impossible) to find for such arms.
Most of the articles I've read use the cartesian distance between the current effector position and the goal position as the function to optimize, and constrain the orientation of the effector to the desired orientation to take care of the angles.
However, I'm not quite sure I understand HOW to constrain that orientation and add that constraint to the optimization problem? The way I've formulated the problem is as follows:
1. The function to optimize takes as input the 6 angles for the robot joints
2. The function computes the current pose using the input angles and forward kinematics
3. The cartesian distance is computed and used as the value to optimize
Thank you!
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Thanks for the reply!
I may have been a bit misunderstood, as I have already constrained the range of values that the angles (and their derivatives) can have. My question was a bit more in relation to constraining the orientation of the end-effector itself within the optimization problem.
In other words, I've seen multiple articles using the distance between the goal and the end-effector's position as the cost function to optimize, while adding an additionnal constraint on the orientation itself. My question was mostly how they did so.
If anyone's interested, I've found a solution to circumvent the problem: My function to optimize is now (cartesian distance) + (difference between the desired orientation and current orientation, in radians). It's not as fancy as I would have hoped, but it gets the job done.
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Hi, I´m Mike, and I´m working on a similar project, this is about a discrete PID control for a Stewart-Gough platform and the method that was chosen will make the robot more precise, using inverse and forward kinematics. First of all thanks.
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Background 
I am working on motion capture data analysis of human walking movement. My goal is to find the variation of markers on different body part in relation to the movement of the main body.
For that I am considering upper trunk body and lower trunk body. Upper trunk body include shoulder, chest and upper abdomen. Lower body includes waist , hip ,lower back and lower abdomen. 
I have markers placed in each body location. I want to create a marker that represents just the body movement and not the surface variations and joint variations so that it can be used as a surface to create reference variation. For that purpose, I am trying to create a kinematic model
Problem
How do I create my virtual point with respect to let's say 3 markers on the upper body? Which motion analysis software can give me this functionality to create some sort of kinematic model. 
- let's say create a vector with respect to a plane made by 3 markers and then create a point from the vector with respect to the plane created by the markers.
The attached picture represents my problem for some rough visualization. Here 2 upper green markers are used to create a vector in red which is used to create a green virtual marker.
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Nexus
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Mathematical
Modeling
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Newton second law.
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Hi to every one,
I am trying to model Cold form steel sections in Abaqus using S4R shell elements. Now the sections need to be connected together at the joints by pinned connections.
I'm using an MPC truss constraint between two nodes near the center. My questions are:
  1. Can you use the MPC in this way for a pinned connection? I have constrained only two nodes from the mesh. One on the master and the other on the slave.
  2. Do I need to kinematic couple a region of nodes to a reference point (RP) for each surface, and then use the MPC on the master surface RP and slave RP.
  3. MPC pinned constraint only constrains translation, but I need to release only one rotation for a bracing type of connection.
Thank you,
Allan
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Good question!
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I am familiar with an understand the standard approach to deriving the kinematic relationships in a moving frame of reference (e.g. Kane and Levinson). I am having some difficulty, however, with Jazar's derivations within his specific frame-referenced approach[1]. The questions are reference specific (the referenced author uses the same framework across multiple texts).
My specific issues are detailed in the attached PDF document (this text editor is a bit limited in regards to presenting formulas). In brief:
  1. Frame referenced time derivatives v. simple time derivatives of the direction cosine matrix (DCM).
  2. The frame referenced first time derivative of a position vector expressed in a different frame v. the standard non-frame referenced time derivative of the same.
  3. The frame referenced first time derivative (G derivative as an example of the frame reference) of the multiplicative term consisting of the DCM (from frame B to frame G) and position vector (in frame B) that appears to drop a term/set it equal to zero in a product rule expansion of the derivative operation.
  4. Algebraic mapping of the DCM across multiplicative terms.
For each question, I have used selected excerpts from the reference, defined terms and shown the details of the 'work' that explain the question. Any help would be greatly appreciated.
References:
  1. Jazar, RN (2011) Advanced dynamics: rigid body, multibody and aerospace applications. Hoboken, New Jersey: John Wiley & Sons, Inc.
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The solution to question 2 is simple enough. The non-frame referenced time derivative approach results in a solution for (left superscript G, left subscript G) r (dot) (right subscript P). The solution from the text is for (left superscript G, left subscript B) r (dot) (right subscript P). Premultiplication of the latter by GRB yields the former.
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I am generating a workspace for a 7 degrees of freedom robotic arm using the values in the table below, however according to the code I have written below the x and y ranges obtained do not seem accurate since the diagram indicates that the effector is able to move 1000mm in either direction in the x and y axes - this is incorrect since the end effector can only move approximately 200mm in either direction in the x and y axes.
DH Parameters for 7DOF robot
I have implemented the Monte Carlo method of generating the workspace, however I'm not sure if this is the correct method that I should be using. Are there alternative methods to calculate the kinematics of a robot?
Any help you could provide me would be greatly appreciated!
a1 = 0;
a2_0 = 0;
a2_1 = 40.09;
a2_2 = 144.54;
a2_3 = 182.62;
a2_4 = 516;
a2_5 = 96;
a3_0 = 40.09;
a3_1 = 40.09;
a4 = 0;
a5 = 0;
a6 = 0.91;
a7 = 0.91;
alph1 = pi/2;
alph2_0 = -pi/2;
alph2_1 = 0;
alph2_2 = 0;
alph2_3 = 0;
alph2_4 = 0;
alph2_5 = 0;
alph3_0 = -pi/2;
alph3_1 = -pi/2;
alph4 = 0;
alph5 = pi/2;
alph6 = -pi/2;
alph7 = -pi/2;
alpha1_min = -1.4835298642 + pi/2;
alpha1_max = 1.4835298642 + pi/2;
alpha2_0_min = -0.75049157836 - pi/2;
alpha2_0_max = 0.80285145592 - pi/2;
alpha2_1_min = pi/2;
alpha2_1_max = pi/2;
alpha2_2_min = 0.75049157836 + pi/2;
alpha2_2_max = -0.80285145592 + pi/2;
alpha2_3_min = 0.75049157836 + pi/2;
alpha2_3_max = -0.80285145592 + pi/2;
alpha2_4_min = -0.75049157836;
alpha2_4_max = 0.80285145592;
alpha2_5_min = -0.75049157836 + pi;
alpha2_5_max = 0.80285145592 + pi;
alpha3_0_min = 0;
alpha3_0_max = 0;
alpha3_1_min = 0;
alpha3_1_max = 0;
alpha4_min = -1.5009831567;
alpha4_max = 1.5009831567;
alpha5_min = -1.3962634016 + pi/2;
alpha5_max = 1.3962634016 + pi/2;
alpha6_min = -1.5009831567 + pi/2;
alpha6_max = 1.5009831567 + pi/2;
alpha7_min = -1.5009831567 + pi/2;
alpha7_max = 1.5009831567 + pi/2;
d1 = 0;
d2_0 = 0;
d2_1 = 0;
d2_2 = 0;
d2_3 = 0;
d2_4 = 0;
d2_5 = 0;
d3_0 = 0.0012217304764 - 431.8 + 144.54;
d3_1 = 0.0012217304764;
d4 = 416.2;
d5 = 0;
d6 = 0;
d7 = 0;
N = 20000;
t1 = alpha1_max + (alpha1_max - alpha1_min)*rand(N,1);
t2_0 = alpha2_0_max + (alpha2_0_max - alpha2_0_min)*rand(N,1);
t2_1 = alpha2_1_max + (alpha2_1_max - alpha2_1_min)*rand(N,1);
t2_2 = alpha2_2_max + (alpha2_2_max - alpha2_2_min)*rand(N,1);
t2_3 = alpha2_3_max + (alpha2_3_max - alpha2_3_min)*rand(N,1);
t2_4 = alpha2_4_max + (alpha2_4_max - alpha2_4_min)*rand(N,1);
t2_5 = alpha2_5_max + (alpha2_5_max - alpha2_5_min)*rand(N,1);
t3_0 = alpha3_0_max + (alpha3_0_max - alpha3_0_min)*rand(N,1);
t3_1 = alpha3_1_max + (alpha3_1_max - alpha3_1_min)*rand(N,1);
t4 = alpha4_max + (alpha4_max - alpha4_min)*rand(N,1);
t5 = alpha5_max + (alpha5_max - alpha5_min)*rand(N,1);
t6 = alpha6_max + (alpha6_max - alpha6_min)*rand(N,1);
t7 = alpha7_max + (alpha7_max - alpha7_min)*rand(N,1);
for i = 1:N
A1 = TransMat(a1,alph1,d1,t1(i));
A2_0 = TransMat(a2_0,alph2_0,d2_0,t2_0(i));
A2_1 = TransMat(a2_1,alph2_1,d2_1,t2_1(i));
A2_2 = TransMat(a2_2,alph2_2,d2_2,t2_2(i));
A2_3 = TransMat(a2_3,alph2_3,d2_3,t2_3(i));
A2_4 = TransMat(a2_4,alph2_4,d2_4,t2_4(i));
A2_5 = TransMat(a2_5,alph2_5,d2_5,t2_5(i));
A3_0 = TransMat(a3_0,alph3_0,d3_0,t3_0(i));
A3_1 = TransMat(a3_1,alph3_1,d3_1,t3_1(i));
A4 = TransMat(a4,alph4,d4,t4(i));
A5 = TransMat(a5,alph5,d5,t5(i));
A6 = TransMat(a6,alph6,d6,t6(i));
A7 = TransMat(a7,alph7,d7,t7(i));
T = A1 * A2_0 * A2_2 * A2_3 * A2_4 * A2_5 * A3_0 * A3_1 * A4 * A5 * A6 * A7;
X=T(1,4);
Y=T(2,4);
Z=T(3,4);
plot3(X,Y,Z,'.')
hold on;
end
view(3);
title('Isometric view');
xlabel('x (mm)');
ylabel('y (mm)');
zlabel('z (mm) ');
% view(2); % top view
% title(' Top view');
% xlabel('x (mm)');
% ylabel('y (mm)');
% view([0 0 1]); % y-z plane
% title('Side view, Y-Z');
% ylabel('y (mm)');
% zlabel('z (mm)');
function [ T ] = TransMat( a,b,c,d )
T = [ cos(d), -sin(d)*cos(b), sin(d)*sin(b), a*cos(d);
sin(d), cos(d)*cos(b), -cos(d)*sin(b), a*sin(d);
0, sin(b), cos(b), c;
0, 0, 0, 1];
end
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Dear Dr. Sara Jones,
Unfortunately, I have no technical skills to guide in solving this problem. Maybe you can use a mechanism simulation software to partially solve this problem.
I worked with an old version of "SimWise 4D" software (WorkingModel 3d) and maybe this solution will be useful in your project:
I hope this information is helpful. Best Regards,
Wagner de Godoy
Brazil
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Hi everybody,
I want to simulate a bubble moving in fluid, say blood using comsol. For such type of interfaces, to couple mesh motion with fluid motion, dose the following kinematic boundary condition is okay?.
u.n= u*nx+v*ny
or n*(u-xt).
here t is time. which one is correct?. Thanks in advance.
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I think the following links can help you. In the first case, ignore the electric field.
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Hi, I am planning a doctoral study using a novel immersive virtual reality playground for children with DCD and TD children, ages 7-10. I was planning on using referred children with DCD but was considering using the DCDQ'07 with the parents of both groups. I am also planning to administer the M-ABC2 for children who have not undergone this evaluation. We will be collecting kinematic data as well as task success, time for task performance and perceived motor competence. Our independent variables include level of immersion, level of output display gain, and setting (a real trampoline in the virtual environment (VE), a virtual trampoline in the VE, and a real trampoline in a real setting.
1.Can you share the full text of this article with me? 2. Would you consider a different tool for this purpose?
Thanks!
Sarina Goldstand
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Good day Sarina. Please find attached the article as requested. With regard to your question, is it possible to test your own sample instead of using a referred sample? The reason for this is that the referred children's parents know they have been identified with DCD and therefor might influence their decision on the DCDQ'07. Also, if you already have referred children and you are planning on testing more children by yourself using the MABC-2 it can have an influence on your results since different examiners may influence the testing procedure. If it was me and it is possible I will get a sample, test the children with the MABC-2 put them into a DCD and non-DCD group and send the DCDQ'07 to those participants. I hope this information is helpful, feel free to ask further questions. Good luck with you PhD. Kind regards Monique
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  • Are the same repetitive kinematic parameters generated by endodontic motors sufficient for the concept of single-file endodontics?
  • Do the simplified single-file systems need more complicated kinematics generated by more talented endodontic motors?
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Thanks Satish Narula Do the simplified single-file systems need more complicated kinematics generated by more talented endodontic motors?
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I am looking for forward kinematic of 3_PRR robots
but not numerical or neural solution
I looking for parametric solution
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Hi Amir
The solution is given in the following reference:
Merlet, J. P. (1996, April). Direct kinematics of planar parallel manipulators. In Proceedings of IEEE international conference on robotics and automation (Vol. 4, pp. 3744-3749). IEEE.
We can found up to 6 solutions to the DKP. It’s simple to found the polynomial equation to be solve by using Maple.
Damien
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I have done detumbling of a 3U cubesat using Bdot law, magnetometers and magnetotorquers. The magnetic field and dynamics and kinematics have been correctly modelled but one of my angular rates is not getting 0.
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If you are 100% sure that your simulation is correct, then the results imply that the angular velocity does not necessarily converge to zero. Naturally, the answer can be found if you perform the Lyapunov stability analysis.
Euler's equation:
I·ω' = − ω × I·ω + m × B
B-dot control:
m = − K·B'
Lyapunov function:
V = ½ ω^T·I·ω
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I am about to visit wind tunnel facilities to test an automotive vehicle. The speed at which the CFD analysis are being carried out is 17 m/s To avoid the blockage effect a scaled model will be created with a scale of 1:3. I am assuming that in order to achieve the kinematic similarity the Reynolds number must be the same. Hence, the speed must be 3 times greater than the speed of CFD simulations. I have assumed that the forces acting on the car will be given by the equation RealForces =(1/scale^2)*ModelForces.
These forces will be the forces for the real car running at three times the speed?How can I calculate the forces acting on the real car at 17m/s??
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Dear Apostolos,
The validity of wind tunnel results obtained in testing of scale models is based on the fluid mechanics Principle of Dynamic Similarity (White, F.M., Fluid Mechanics, 6 ed., Boston, USA: McGraw-Hill, 2003, p. 866) which states that: "If two physical phenomena can be described using the same formulation (same equations and same initial and boundary conditions), the solutions for one of the phenomena are valid for the other one."
For the motion of air around and obstacle, this Principle guarantees that the non-dimensional results measured in a wind tunnel for a scale model (e.g., lift, drag, and pitching moment coefficients) will be the same as for the real, full-scale obstacle if the following conditions are fulfilled:
  1. Geometric similarity: all relevant aerodynamic features of the real obstacle must be accurately replicated in the scale model
  2. The Mach number must be the same for the model and obstacle θ γ
  3. (as you said) The Reynolds number must also be the same
  4. Heat transfer (thermal effects) and diffusion can be neglected
For CFD, this is not usually a problem, since you have much flexibility in defining the boundary conditions and other settings such that these 4 conditions are satisfied and, for example, Re and M match those of the real fluid problem.
Now the dilemma comes when trying to extrapolate wind tunnel results to the real fluid problem: If the fluid properties for both the tests and real case are the same (i.e., same speed of sound (T), ρ and μ), and the scale model is smaller or larger than the real obstacle, it is obvious that it is not possible to have simultaneously the same M and Re as in the real problem. If we cannot replicate simultaneously both parameters, it is then necessary to choose which one will be kept similar to the real case. Generally, we choose the parameter with a stronger influence on the flow. For instance, roughly speaking M is dominant for supersonic flows and Re for subsonic flows (your case). Thus, for example, in high-subsonic testing, we would strive to work with the same Re as in the real case, and would not pay so much attention to M. Effectively, this means that we are not complying fully with the requirements of the Principle of Dynamic Similarity, and thus the test results have some error respect to the behavior in the real case. Many researchers have characterized the Re and M scaling effects to be able to correct for this error when extrapolating the wind tunnel results to the real case, if the Re and/or M in the tunnel are different than those of the real case.
If the fluid properties for both your tests and real case are the same, you should try to work with a model as similar as possible in dimensions the real obstacle, bearing in mind also these recommendations (Barlow, J.B., Rae, W.H., Pope, A., Low-speed Wind Tunnel Testing, 3 ed., NY, USA: Wiley & Sons, 1999, p. 713):
  • Blocking coefficient (ratio of frontal area of model to frontal area of test chamber): should be less than 0.1
  • Wingspan (or width) of the model: should be less than 4/5 (80%) of test chamber width
If you manage to have same Re and M, then the lift and drag coefficients (cL = Lift/(0.5*rho*V^2*S) and cD = Drag/(0.5*rho*V^2*S)) that you obtain from the tunnel can be extrapolated to the real vehicle. If you manage to have only the same Re, the lift and drag coefficients that you obtain should be corrected, but this error should not be very large and maybe the values from the tunnel are still valide to you. If you don't manage to have the same Re, then you could correct the cL and cD following the procedure described in the attached image from White's book Fluid Mechanics, for which you need to have values of cL or cD at several flow velocites (i.e., at several Reynolds numbers).
Hope this is useful,
Jose
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I would like to be able to import footage from 2 or more cameras to analyze the motion of mammals. Lmbs is what mainly interests me.
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Have you got more suggestions?
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Kinovea
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We can choose one or two back stresses when we set up the nonlinear kinematic/isotropic hardening in ABAQUS. How do we decide the number of back stresses? let say model under uniaxial or multiaxial load.
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I am looking for a GPS receiver with a sampling rate greater than 1 Hz. I looked online for Real time kinematics GPS receiver which have higher sampling rate but they are expensive. I am looking for other recommendations
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Do you mean GNSS receivers with sampling rate higher than 1 sec? Most geodetic receivers available on the market are capable of collecting sampling rate higher than 1 sec.
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Please see the image attached for the complete question.
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Dear Dr. Abhishek Arora,
I've tried to recreate the joint model in the Interactive Physics (http://www.design-simulation.com/IP/index.php), but this software is a limited version of Working Model 2d.
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I simulated inverse kinematic of ur10 and T01,T12,T23,...
are complex .is it true? I attached symbolic kinematic (mfile) and error.