| |
| |
| |
|
Determination of variance in measurement of relative angle between infrared beacon and scanner
Krejsa, Jiří ; Růžička, M. ; Vojta, J.
Mobile robot localization is one of essential components for successful robot navigation. Localization techniques based on active landmarks commonly utilize probabilistic state estimation methods, e.g. Extended Kalman filter (EKF). In order to function properly, determination of process and measurement noise variances is essential in EKF. This paper is focused on determination of variance in measurement of relative angle between the active landmark, represented by infrared beacon and device positioned on the robot, beacon scanner. Variance values are determined in a number of environment conditions. The results indicate that for the beacon type used the variance essentially holds with the percentage of unsuccessful readings being the only variable effected by changing environment. This observation justifies the usage of measured variances in EKF based localization system.
|
| |
| |
|
Oscillation of Interfacial Meniscus during the Formation of Bubbles
Stanovský, Petr ; Růžička, Marek
A closer look at the interphase meniscus in the model system with a transparent plate using a high-speed camera has showed that after detachment of the bubble the meniscus moves to the lower orifice rim. On that rim the meniscus oscillate dumped by increasing pressure in the space below the plate. In the description of the bubble growth at the orifice during so called waiting period accrue the equations describing the oscillatory behavior of the meniscus. Together with the nonlinear Rayleigh-Plesset equation it results in a bifurcation behavior - the volume of bubbles differ by up to 50% from the mean at certain values of the gas flow. This phenomenon has not been previously identified as the time-averaged values of bubble sizes conceal this effect.
Fulltext: PDF
|
| |
| |
|
Parameters Affecting Process of Particles Sedimentation: III
Kulaviak, Lukáš ; Růžička, Marek ; Drahoš, Jiří ; Hladil, Jindřich
The aim of our contribution is to study the effect of the particles properties on their settling behaviour in solid-liquid suspensions. Generally, the particles interact mutually in a complex way. They are also coupled with the motion of the liquid whose flow they generate. The resulting behaviour depends on many mechanical particle properties (roughness, shape, size, abrasive hardness, texture, fine particle presence) and electrochemical properties of the interface between the particles and water (surface tension, zeta-potential, electrostatic potential, etc.).
|