Determining angular velocity and angular acceleration of a projectile using triaxial acceleration measurements

2000 ◽  
Author(s):  
Mark Costello ◽  
Thanat Jitpraphai
Keyword(s):  
Angular Velocity ◽  
Angular Acceleration

Kinematics of rotation in place during defense turning in the crayfish Procambarus clarkii

2001 ◽  
Vol 204 (3) ◽  
pp. 471-486 ◽  
Author(s):  
N. Copp ◽  
M. Jamon
Keyword(s):  
Angular Velocity ◽  
Procambarus Clarkii ◽  
Angular Acceleration ◽  
The Body ◽  
Simple Variation ◽  
Freely Behaving ◽  
Leg Motion ◽  
Two Phases ◽  
Analysis System ◽  
Final Orientation

The kinematic patterns of defense turning behavior in freely behaving specimens of the crayfish Procambarus clarkii were investigated with the aid of a video-analysis system. Movements of the body and all pereiopods, except the chelipeds, were analyzed. Because this behavior approximates to a rotation in place, this analysis extends previous studies on straight and curve walking in crustaceans. Specimens of P. clarkii responded to a tactile stimulus on a walking leg by turning accurately to face the source of the stimulation. Angular velocity profiles of the movement of the animal's carapace suggest that defense turn responses are executed in two phases: an initial stereotyped phase, in which the body twists on its legs and undergoes a rapid angular acceleration, followed by a more erratic phase of generally decreasing angular velocity that leads to the final orientation. Comparisons of contralateral members of each pair of legs reveal that defense turns are affected by changes in step geometry, rather than by changes in the timing parameters of leg motion, although inner legs 3 and 4 tend to take more steps than their outer counterparts during the course of a response. During the initial phase, outer legs 3 and 4 exhibit larger stance amplitudes than their inner partners, and all the outer legs produce larger stance amplitudes than their inner counterparts during the second stage of the response. Also, the net vectors of the initial stances, particularly, are angled with respect to the body, with the power strokes of the inner legs produced during promotion and those of the outer legs produced during remotion. Unlike straight and curve walking in the crayfish, there is no discernible pattern of contralateral leg coordination during defense turns. Similarities and differences between defense turns and curve walking are discussed. It is apparent that rotation in place, as in defense turns, is not a simple variation on straight or curve walking but a distinct locomotor pattern.

Mathematical Models of Control Systems of Angular Speed of Steam Turbines for Diagnostic Tests of Automatic and Mechatronic Devices

2013 ◽  
Vol 198 ◽  
pp. 519-524
Author(s):  
Grzegorz Redlarski ◽  
Janusz Piechocki ◽  
Mariusz Dąbkowski
Keyword(s):  
Angular Velocity ◽  
Power System ◽  
Control Systems ◽  
Working Conditions ◽  
Diagnostic Tests ◽  
Angular Acceleration ◽  
Angular Speed ◽  
Physical Parameters ◽  
Steam Turbines ◽  
Parallel Operation

In many automatics and mechatronics systems accurate modeling of several physical processes is needed. In power system, one of these is the process of control of angular velocity of power blocks during their connection to parallel operation. This process is extremely dynamic and the response of control system results from continuous changes in many physical parameters (temperature, pressure and flow of the working medium, etc.). An accuracy of modeling this process influences int. al. on: quality of the automatic synchronizer diagnostic tests in the laboratory, as well as the possibility of evaluation of prospects for connection process in the power system, without the automatic synchronizer [. Automatics systems used for research and diagnosis of automatic synchronizers are known in the literature as and simulators [2, . To impose similar to real working conditions, it is required to implement an appropriate models of control systems. One of such models, representative for the larger population of objects, is model of control systems of angular velocity. Currently used models, e.g. [3, 4, 5, , allow to approximate the response of real object, or to impose higher restricted conditions of work, for example: related to the angular acceleration dω/dt, the size of overshoots and decay time of transitional characteristics, while accurate modeling the real working conditions using them is not possible. Furthermore, their use requires knowledge of the (often difficult to access) object parameters and time-consuming selection of manual procedure of certain substitute settings, occurring in these models. To eliminate inconveniences mentioned above, in the paper the proposal and mathematical modeling procedure is presented, which allow to obtain much more accurate transitional characteristics of real objects.

Gyroscope-Free Link Parameter Measurement Using Accelerometers and Magnetometer

2014 ◽  
Author(s):  
Vishesh Vikas ◽  
Carl D. Crane
Keyword(s):  
Angular Velocity ◽  
Joint Angle ◽  
Inertial Sensors ◽  
Angular Acceleration ◽  
Parameter Measurement ◽  
Joint Angles ◽  
Symmetry Constraint ◽  
Estimation Techniques ◽  
Angular Velocities ◽  
Joint Parameters

Knowledge of joint angles, angular velocities is essential for control of link mechanisms and robots. The estimation of joint angles and angular velocity is performed using combination of inertial sensors (accelerometers and gyroscopes) which are contactless and flexible at point of application. Different estimation techniques are used to fuse data from different inertial sensors. Bio-inspired sensors using symmetrically placed multiple inertial sensors are capable of instantaneously measuring joint parameters (joint angle, angular velocities and angular acceleration) without use of any estimation techniques. Calibration of inertial sensors is easier and more reliable for accelerometers as compared to gyroscopes. The research presents gyroscope-less, multiple accelerometer and magnetometer based sensors capable of measuring (not estimating) joint parameters. The contribution of the improved sensor are four-fold. Firstly, the inertial sensors are devoid of symmetry constraint unlike the previously researched bio-inspired sensors. However, the accelerometer are non-coplanarly placed. Secondly, the accelerometer-magnetometer combination sensor allows for calculation of a unique rotation matrix between two link joined by any kind of joint. Thirdly, the sensors are easier to calibrate as they consist only of accelerometers. Finally, the sensors allow for calculation of angular velocity and angular acceleration without use of gyroscopes.

Research on the Kinematic Characteristics of Digging Tree Mechanism of Tree Transplanter

2014 ◽  
Vol 620 ◽  
pp. 381-387 ◽  
Author(s):  
De Jin Zhao ◽  
Yan Ling Guo ◽  
Wen Long Song
Keyword(s):  
Angular Velocity ◽  
Dynamic Simulation ◽  
Analytical Method ◽  
Angular Acceleration ◽  
Hydraulic Cylinder ◽  
Matlab Software ◽  
Kinematic Characteristics ◽  
Adams Software ◽  
Model File

In order to study the kinematic characteristics of the tree transplanter and the hydraulic cylinder, this paper established the model of the tree transplanter with the Cero2.0 software and analyzed kinematic characteristics of the hydraulic cylinder and the tree spade when the tree spade was driven by the hydraulic cylinder with the analytical method. The dynamic simulation curves of the angular velocity and the angular acceleration of the hydraulic cylinder can be obtained with the Matlab software. Then the appropriate format model file was imported into Adams software, and the angular velocity and the angular acceleration of the hydraulic cylinder were analyzed and simulated in Adams. The obtained curves in Adams software were compared with the curves obtained with the Matlab using the analytical method. The result revealed that the trends of the two ways simulation curves were consistent. The comparison showed the analytical method of kinematic characteristics of the tree transplanter and hydraulic cylinder was correct.

Kinematic Analysis of Mechanisms by the Complex Conjugate Exponential Method

1975 ◽  
Vol 97 (3) ◽  
pp. 795-799 ◽  
Author(s):  
J. A. Smith
Keyword(s):  
Angular Velocity ◽  
Closed Form ◽  
Kinematic Analysis ◽  
Angular Position ◽  
Angular Acceleration ◽  
Dynamic State ◽  
Complex Conjugate ◽  
Iterative Techniques ◽  
Numerical Example ◽  
Exponential Method

Generalized closed-form expressions are presented for the analysis of angular and path position and dynamic state properties of an n link mechanism with single or multiple prescribed input specifications. The complex conjugate concept is extensively used to formulate these explicit expressions. A numerical example of a six-bar mechanism is presented, and the closed-form expressions are used to calculate—without graphical, numerical, or iterative techniques—the angular position, angular velocity, and angular acceleration of each link.

Dynamics Simulation of Spacesuit Mobility Measuring Manipulator Based on Matlab

2011 ◽  
Vol 138-139 ◽  
pp. 345-351
Author(s):  
Shu Hui Xu ◽  
Lei Zhou
Keyword(s):  
Angular Velocity ◽  
Space Station ◽  
Angular Acceleration ◽  
Basic Data ◽  
Dynamics Simulation ◽  
Measuring System ◽  
Dynamics Model ◽  
Important Data ◽  
Good Basis ◽  
Operational Ability

The operational ability and mobility of astronaut in spacesuit is an important data for evaluation of the spacesuit, and to know it before use is also a basic data for the design of space station and spaceship. For this reason, mechanical arms were developed to measure the mobility and operational ability of astronaut in spacesuit. However, the mass and motion inertia are always influence the measuring system. This paper studied the dynamics characteristics of the mechanical arms. Dynamics model of the mechanical arms were setup and solved by MATLAB. Angle, angular velocity and angular acceleration of each joint were analyzed. The simulation supply a good basis for the development of the measuring manipulator, and it is helpful for the high accurate measurement.

Some Dimensions of the Angular Acceleration Receptor Systems of Cephalopods

1984 ◽  
Vol 64 (1) ◽  
pp. 55-79 ◽  
Author(s):  
Linda Maddock ◽  
J. Z. Young
Keyword(s):  
Angular Velocity ◽  
Frequency Band ◽  
Deep Sea ◽  
Horizontal Plane ◽  
Angular Acceleration ◽  
The Body ◽  
The Other ◽  
Radius Of Curvature ◽  
Internal Radius ◽  
Neutrally Buoyant

The shapes and dimensions of the statocysts of cephalopods have been measured and compared with the semi-circular canals of vertebrates. The cavities grow much more slowly than the body as a whole, but there are knobs, anticristae, which restrict the cavity, and these grow relatively faster. This ensures that the flow of endolymph across the cupulae remains small. Where the liquid is constrained within canals the radius of curvature of the whole canal, R, is similar to that of fishes, whereas its internal radius, r, is twice as large in non-buoyant and four times as large in deep-sea buoyant cephalopods as in fishes of similar size. As in fishes the restriction is greatest in the horizontal plane, providing for operation at higher frequencies in turning about the yaw axis.The statocysts of seven species of Loligo all have similar proportions. The largest individuals of 16 genera of non-buoyant squids also have these same relative dimensions. The statocyst of Sepia is more like that of non-buoyant than of other buoyant cephalopods but yet differs significantly from that of Loligo at all sizes. On the other hand 21 genera of squids known to be neutrally buoyant are very different. Their statocysts are often larger than in the non-buoyant forms and there is less restriction of the cavity by anticristae. The greater flow of endolymph acting across the cupulae presumably provides greater sensitivity at the lower frequencies of turning of these deep-sea animals.The data suggest that the cristae of the cephalopod statocyst may operate in the frequency band where they act as angular accelerometers whereas the vertebrate semi-circular canals operate at higher frequencies as angular velocity meters.

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