Errors in the Center and Angle of Rotation of a Joint: An Experimental Study

1982 ◽  
Vol 104 (3) ◽  
pp. 232-237 ◽  
Author(s):  
M. M. Panjabi ◽  
V. K. Goel ◽  
S. D. Walter ◽  
S. Schick

The error sensitivity in the determination of center and angle of rotations of a body joint performing planar motion is studied. A simple experiment is described to measure the errors in these two kinematic parameters as functions of errors in the input coordinates of markers. The effect of varying the marker locations and the size of motion-step is also studied. The errors in the center of rotation are found to increase dramatically when the two markers subtend angles of about 0 deg or 180 deg and when the motion step size decreases to 1 deg or less. Similar results are found for errors in the angle of rotation which, in addition, increase with decrease in the radius of the markers.

Author(s):  
Ivelin Kostov

In the work brought some experimental data of kinematic parameters of movement of cars forced idle, as the software product was used to diagnose 900 ATS, which recorded kinematic parameters of vehicle. On the basis of the conducted experimental research results are shown tabulated and analysed.


2018 ◽  
Vol 77 (4) ◽  
pp. 230-240
Author(s):  
D. P. Markov

Railway bogie is the basic element that determines the force, kinematic, power and other parameters of the rolling stock, and its movement in the railway track has not been studied enough. Classical calculation of the kinematic and dynamic parameters of the bogie's motion with the determination of the position of its center of rotation, the instantaneous axes of rotation of wheelsets, the magnitudes and directions of all forces present a difficult problem even in quasi-static theory. The paper shows a simplified method that allows one to explain, within the limits of one article, the main kinematic and force parameters of the bogie movement (installation angles, clearance between the wheel flanges and side surfaces of the rails), wear and contact damage to the wheels and rails. Tribology of the railway bogie is an important part of transport tribology, the foundation of the theory of wheel-rail tribosystem, without which it is impossible to understand the mechanisms of catastrophic wear, derailments, contact fatigue, cohesion of wheels and rails. In the article basic questions are considered, without which it is impossible to analyze the movement of the bogie: physical foundations of wheel movement along the rail, types of relative motion of contacting bodies, tribological characteristics linking the force and kinematic parameters of the bogie. Kinematics and dynamics of a two-wheeled bogie-rail bicycle are analyzed instead of a single wheel and a wheelset, which makes it clearer and easier to explain how and what forces act on the bogie and how they affect on its position in the rail track. To calculate the motion parameters of a four-wheeled bogie, it is represented as two two-wheeled, moving each on its own rail. Connections between them are replaced by moments with respect to the point of contact between the flange of the guide wheel and the rail. This approach made it possible to give an approximate estimation of the main kinematic and force parameters of the motion of an ideal bogie (without axes skewing) in curves, to understand how the corners of the bogie installation and the gaps between the flanges of the wheels and rails vary when moving with different speeds, how wear and contact injuries arise and to give recommendations for their assessment and elimination.


2005 ◽  
Vol 11 (3) ◽  
pp. 170-173 ◽  
Author(s):  
Mehmet Dündar ◽  
Izzet Koçak ◽  
Nil Çulhaci ◽  
Haluk Erol

Author(s):  
LJ. Tanovic ◽  
P. Bojanic ◽  
R. Puzovic ◽  
S. Klimenko

This paper offers an experimental study of the microcutting mechanisms in marble grinding to aid the optimization of the marble grinding process. The necessity for investigating these mechanisms is dictated by the increased use of marble in many applications and the fact that grinding and polishing processes are the dominant technologies used to meet surface finish requirements in this natural material. The experiments are aimed at the determination of the normal component of the cutting force and of the grain traces in microcutting with a single diamond grain. The investigations carried out make provisions for establishing critical grain penetration and cutting depths and allow the prediction of the normal cutting force component as a function of grain penetration speed and depth.


2000 ◽  
Vol 355 (1396) ◽  
pp. 441-447 ◽  
Author(s):  
T. Yanagida ◽  
S. Esaki ◽  
A. Hikikoshi Iwane ◽  
Y. Inoue ◽  
A. Ishijima ◽  
...  

Recent progress in single–molecule detection techniques is remarkable. These techniques have allowed the accurate determination of myosin–head–induced displacements and how mechanical cycles are coupled to ATP hydrolysis, by measuring individual mechanical events and chemical events of actomyosin directly at the single–molecule level. Here we review our recent work in which we have made detailed measurements of myosin step size and mechanochemical coupling, and propose a model of the myosin motor.


2018 ◽  
Vol 157 ◽  
pp. 02003 ◽  
Author(s):  
Peter Baran ◽  
Pavol Šťastniak ◽  
Pavol Kukuča ◽  
Miloš Brezáni

Article deals with description of non-conventional mechanism FIK and mechanism with ring, which may be suitable for special applications in the engineering industry. It is possible to use not only classical crank mechanisms, but also non-conventional mechanisms in design of piston machines. Investigation of kinematic parameters of the machines is important step to know its basic movement behaviour, and from this, it is then possible to create the alternate dynamic model or force analysis. For kinematic comparison will be designed the same basic geometric conditions in both types of models. In terms of comparisons will be monitored mainly points on wobble board and the main part will be determination of piston stroke.


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