Rotational Motion

algorithms are widely used in inverse synthetic aperture radar (ISAR) imaging. In the standard RD algorithm, envelope alignment and autofocus are first applied to transform the original data into equivalent turntable target data, and then FFT is used for the image formation. Usually, the migration through resolution cells (MTRCs) due to target rotation is ignored. With the improvement of resolution or the increase of target size, MTRCs cannot be ignored and must be mitigated. For high speed moving targets, the most widely used 'stop-and-go' data model is violated. In this case, the mitigation of MTRCs becomes even more complicated. In the paper, technical issues associated with high resolution ISAR imaging of high speed moving targets are addressed. A preprocessing algorithm is first proposed to convert the non-coherent raw ISAR data into coherent data, then a keystone formatting algorithm developed for the imaging of slow ground moving targets in SAR is applied to mitigate the MTRCs owing to rotational motion, and, finally, a high resolution time -frequency analysis based range -instantaneous Doppler (RID) algorithm is used to produce the focused ISAR image. Numerical examples are provided to illustrate the performance of the proposed approach.

Robotic grippers are widely used in industries for handling objects. This paper presents the procedure of design and fabrication of a stepper motor controlled robotic gripper to be used in industries for handling small objects. The gripper has one degree of freedom for linear motion and one degree of freedom for rotational motion. A linear actuator has been employed to give translational motion to the gripper. Based on the design requirement data, a kinematic analysis has been done to accurately predict the design parameters useful in proper selection of motor and linear actuator.

This study at aims performing the stability analysis of the rotational motion to artificial satellites using quaternions to describe the satellite attitude (orientation on the space). In the system of rotational motion equations, which is composed by four kinematic equations of the quaternions and by the three Euler equations in terms of the rotational spin components. The influence of the gravity gradient and the direct solar radiation pressure torques have been considered. Equilibrium points were obtained through numerical simulations using the softwares Matlab and Octave, which are then analyzed by the Routh-Hurwitz Stability Criterion.

Our recent results on stability and multiplicity of flow states for confined flows of an incompressible Newtonian fluid are surveyed. The considered laminar flows are caused by either thermal, mechanical, or electromagnetic effects and beyond the stability limit exhibit multiplicity of stable, steady or oscillatory, asymptotic states. Stability diagrams as well as examples of multiple flow states are given. It

We discuss the motion control of a two-wheeled mobile robot. In the design of a controller for the system, a kinematic model is usually used; the wheels do not skid at all and the mobile robot is regarded as a 3D 2-input nonholonomic system without drift. Many controllers based on the kinematic model have been proposed. However, in a real world, the wheels may skid on the ground or float away from the ground according to the rolling motion of the body. Therefore, we derive a dynamic model of a two-wheeled mobile robot which implies the translational motion with 3 degrees-of-freedom and the rotational motion with 3 degrees-of-freedom of the body and the rotational motion with one degree-of-freedom of each wheel, and then reduce the dynamic model to the kinematic model under certain assumptions. We design a controller based on the kinematic model by extending the Lyapunov control and analyze whether the designed controller works well in a real world by numerical simulations based on the dynamic model

Searching to encourage and increase the desire of students to seek a  vocation in the study of engineering and science, we wanted to implement and validate experimentally and numerically, the study of the movement of a mechanical oscillator using, in this case, a physical pendulum, formed by a bar and a disk. In this article has done the study the physical pendulum, combining a methodology that involves an experimental arrangement and the implementation of simulations developed in Python, with the aim objective of offering to students a visual and interactive experience, so that they can understand in a simpler way topics covered in the theoretical physics course, in such a way that is different from the typical physical-mathematical formalism. This study was carried out with low-cost materials and easy access, in addition to the great social impact that I had against the acceptance and assessment by the students with whom this work was applied. This work was developed in three phases: first, to measure the period of oscillation of a physical pendulum experimentally. Second, the approach of the analytical model to compare with the experimental results. Third, the development of a dynamic
simulator according to the predictions of the theoretical model. The students found a didactic and different way of studying the physical pendulum. Finally, it was possible to demonstrate a self-consistency between the experimental and numerical results of the system studied in this work.

In this research, the experimental investigation of unsteady flow around a cylinder model with three plates perpendicular to it has been discussed. This study has been done at different speeds, primary model angle of attacks and length ratios. The results show that the model has steady and unsteady oscillation and rotational motions. These types of behaviors depend on the plate's length ratio, primary object angle of attack, and free stream velocity. The model has damping motion around an angle of 60 degree, at low speed and length ratio. The greatest oscillational or rotational flow has appeared at initial angle of attack of 0 degree. In low length ratio, the regime of motion is oscillations that it changed to rotational motion when the length ratio and free stream velocity increase. The variation of angular velocity at length ratio of 1 and 4, with respect to time, are accompanied with reduction of vibrations range per motion. Also, over time, the vibrational velocity of the model is reduced. In addition, the results show that by increasing the Reynolds Number, Strouhal number becomes constant.

This paper addresses the problem of estimating, analyzing and tracking objects moving with spatio-temporal rotational motion (i.e. the angular velocity of spinning or orbiting motions). It is assumed that the digital signals of interest are acquired from a camera and structured as digital image sequences. The trajectories in the signal are two-dimensional spatial projections in time of motion taking place in a three-dimensional space. The purpose of this work is to focus on the rotational motion i.e. estimate the angular velocity and acceleration. In natural scenes, rotational motion usually evolves on a trajectory and then composes with translational or accelerated motion. This paper shows that the trajectory parameters and the rotational parameters can be eficiently estimated and tracked either simultaneously or separately. The final goal of this work is to provide selective reconstructions of moving objects of interest. This paper constructs new continuous wavelet transforms that can be tuned to both translational and rotational motion. The parameters of analysis that are taken into account in these rotational wavelet transforms are space and time position, velocity, spatial scale, angular orientation and angular velocity. The continuous wavelet functions are finally discretized for signal processing. The link between rotational motion, symmetry and critical sampling is also presented. Simulations have been performed with estimation, detection and tracking o n natural scenes.

Reported in this paper are the implementation and testing of the real-time control of a two-wheeled mobile robot. The robot is underactuated, its mobility and control inputs being three and two, respectively. The control challenge faced here is to reduce the oscillations of the intermediate body while following a desired path. A controller, introduced elsewhere, is implemented using a real-time operating system on a novel control architecture. The control algorithm was tested using three different test motions: translational, rotational, and uphill.

A microengine uses two synchronized linear actuators as a power source and converts oscillatory motion from the actuators into constant rotational motion via direct linkage connection to an output gear or wheel. The microengine provides output in the form of a continuously rotating output gear that is capable of delivering drive torque at a constant rotation to a micromechanism. The output gear can have gear teeth on its outer perimeter for directly contacting a micromechanism requiring mechanical power. The gear is retained by a retaining means which allows said gear to rotate freely. The microengine is microfabricated of polysilicon on one wafer using surface micromachining batch fabrication.