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.

Curve walking in freely moving crayfish (Procambarus clarkii)

1998 ◽  
Vol 201 (9) ◽  
pp. 1315-1329 ◽  
Author(s):  
P Domenici ◽  
M Jamon ◽  
F Clarac
Keyword(s):  
Procambarus Clarkii ◽  
Angular Acceleration ◽  
The Body ◽  
Body Axis ◽  
Power Stroke ◽  
Body Rotation ◽  
Freely Moving ◽  
Analysis System ◽  
Leg Kinematics ◽  
Phase Relationships

The curve walking of freely moving crayfish trained to walk along a curved path during homing behaviour was investigated using a video-analysis system. The leg kinematics and leg phase relationships, as well as the relationship between stepping patterns and body axis rotation measured relative to external references, were studied. <P> The anterior and posterior extreme positions of the power stroke (AEP and PEP, respectively) and step amplitudes were analysed. As in a previous study on crayfish curve walking on a treadmill, PEPs were more posterior in outer legs (the legs on the outside of the turn) than in the inner legs. As a result, outer legs showed larger step amplitudes than inner legs. Leg kinematics varied within each walking sequence. AEP leg angles (the angles between the body and leg axes at the AEP) tended to decrease over time for inner legs and increase for outer legs. This leg angle drift was present mainly in the anterior legs and it suggests that these legs did not completely compensate for the body rotation after each step. In addition, leg angle asymmetries in a direction opposite to that of leg angle drift were observed at the start of each curve-walking sequence, suggesting that the extensive training (3 weeks) may have allowed crayfish to anticipate the leg angle drift. <P> The rotational component of curve walking showed a discontinuous pattern, with the animal's body axis turning towards the inside of the curve only periodically. Analysis of cross-correlation functions showed that the angular acceleration of the body axis in the direction of the turn occurred during the power strokes of inner legs 2 and 5 and outer leg 4. While the tripod formed by these three legs showed in-phase relationships, the legs of the corresponding contralateral tripod (outer legs 2 and 5 and inner leg 4) were not in phase. We hypothesize that inner legs 2 and 5 and outer leg 4 act synergically causing the inward body rotation observed in curve-walking crayfish and that some of the asymmetries found in step geometry may be a passive phenomenon due to the body rotation.

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.

scholarly journals Control of arm movement: reaching synergies for neuroprosthesis with life-like control

2002 ◽  
Vol 12 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Mirjana Popovic ◽  
Dejan Popovic ◽  
Rajko Tomovic
Keyword(s):  
Angular Velocity ◽  
Arm Movement ◽  
Elbow Flexion ◽  
The Body ◽  
Control Mechanisms ◽  
Variable Loading ◽  
Flexion Extension ◽  
Two Phases ◽  
The Impact ◽  
Functional Task

This paper presents control methods for restoration of reaching and grasping that mimics the mapping in the space of output states found in healthy subjects. The hypothesis was that the externally driven movements are most likely to advance the recovery of functioning if they follow lifelike control mechanisms. For this, it is important to analyze movement considering the conditions such as: 1) variety of functional tasks (drinking, writing, using computer disk); 2) different locations of the object (with respect to the body); with respect to the active arm); 3) variable loading of the hand (light, heavy); and 4) available grasp strategy (palmar, lateral, pinch). The overall goals of our study were the following 1) identification of coordinated synergies in functional tasks, 2) investigation of differences and similarities between these synergies related to different grasp types, and 3) analysis of the impact of direction, distance and load to synergies. Three spatial reaching synergies were validated for the following coordinated rotations: shoulder adduction/abduction vs. elbow flexion/extension angular velocity (synergy SI), humeral rotation vs. elbow flexion/extension angular velocity (synergy S2), and shoulder vs. elbow flexion/extension angular velocity (synergy S3). These are timely synchronized with the phases of functional tasks; where four reaching phases were distinguished. Here, we present alternation of synergies' coupling during successive phases of a functional task. Preliminary results indicate that the two phases of a functional task termed "no-object" phases used one coupling, between synergies S2 and S3; while the two other phases termed "object" phases were coupled by synergies SI and S2. We established the generalization on the following two objectives: the discrimination of tasks' phases and matching the synergies with task phases. This result reduces the number of mappings necessary for the design of neuroprosthesis with life-like control.

Computation of Rigid-Body Angular Acceleration From Point-Acceleration Measurements

1987 ◽  
Vol 109 (2) ◽  
pp. 124-127 ◽  
Author(s):  
Jorge Angeles
Keyword(s):  
Angular Velocity ◽  
Rigid Body ◽  
Measurement Errors ◽  
Angular Acceleration ◽  
The Body ◽  
The Other ◽  
Compatibility Conditions ◽  
Other Hand ◽  
The One

The computation of the angular acceleration of a rigid body from measurements of accelerations of three noncollinear points of the body is presented in this paper. This is based on algorithms presented previously for the computation of the orientation and the angular velocity of a rigid body from measurements of position and velocity of three noncollinear points of the body. Moreover, compatibility conditions that the said point measurements should verify are introduced. These are necessary to verify the rigidity assumption on the one hand; on the other hand, they are introduced as a means of filtering roundoff and/or measurement errors, which is particularly useful if redundant measurements are taken, i.e., on more than three points. The procedure is illustrated with a fully solved example.

Minimal Spatial Accelerometer Configurations

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
Thomas R. Williams ◽  
Donald W. Raboud ◽  
Ken R. Fyfe
Keyword(s):  
Angular Velocity ◽  
Special Class ◽  
Design Methodology ◽  
Angular Acceleration ◽  
The Body ◽  
Specific Force ◽  
Geometric Conditions ◽  
Minimum Number ◽  
First Time ◽  
General Motion

It is well established that it is necessary to use a minimum of six accelerometers to determine the general motion of a rigid body. Using this minimum number of accelerometers generally requires that a nonlinear differential equation be solved for the angular velocity and that the estimate of angular velocity that is obtained from the solution of this equation be used in the calculation of the specific force at a point. This paper serves two main purposes. First it discusses, for the first time, the geometric conditions that must be satisfied by an arrangement of six accelerometers so that it is possible, in principle, to determine the motion of the body to which they are attached. Second, a special class of minimal accelerometer configurations that yields angular acceleration as a linear combination of accelerometer measurements is identified, and a design methodology for this special class is presented.

A Study on Mixed Kinetic-Kinematic Equations for Multibody Systems

2013 ◽  
Author(s):  
Sung-Soo Kim ◽  
Bongcheol Seo ◽  
Myungho Kim
Keyword(s):  
Angular Velocity ◽  
Velocity Vector ◽  
Reference Frames ◽  
Time Derivative ◽  
Kinetic Equations ◽  
Angular Acceleration ◽  
The Body ◽  
Integration Step ◽  
Angular Velocity Vector ◽  
The Relationship

In this paper, mixed kinetic-kinematic equations for a multibody system have been studied in order to resolve the difficulties of non-integrability of angular velocity vectors. As for the kinetic equations, the Newton-Euler equations of motion are considered. They are derived in terms of angular velocity and angular acceleration vectors expressed in the body fixed reference frames. As for the kinematic compatibility equations, two different equations are considered. One is from the relationship between the angular velocity vector and the time derivatives of Euler parameters. The other is from the relationship between the rotational orientation matrix, its time derivative, and the angular velocity vector. In order to investigate the accuracy of the solution methods using two different kinematic compatibility equations, simulations of a spherical pendulum model and a 1/6 robot vehicle model have been carried out. With different integration step-sizes, the constraint violation errors have been also investigated.

Roles of eyes, leg proprioceptors and statocysts in the compensatory eye movements of freely walking land crabs (Cardisoma guanhumi)

1998 ◽  
Vol 201 (24) ◽  
pp. 3395-3409
Author(s):  
H. Paul ◽  
W. J. P. Barnes ◽  
D. Varjú
Keyword(s):  
Eye Movements ◽  
Angular Velocity ◽  
Regression Line ◽  
Angular Acceleration ◽  
High Gain ◽  
The Body ◽  
Retinal Slip ◽  
Land Crab ◽  
Land Crabs ◽  
Cardisoma Guanhumi

The compound eyes, the canal organs of the statocysts and proprioceptors in the legs all generate compensatory eye movements in the horizontal plane in the land crab Cardisoma guanhumi. Frequency analyses of the compensatory eye reflexes elicited by each of these inputs show that visual (V) and proprioceptive (P) reflexes respond best below 0.1 Hz, while statocyst (S)reflexes only achieve a high gain above this frequency. They thus increase the range of frequencies over which compensation can occur. Eye and body movements were recorded in an arena under all possible combinations of crabs seeing or blind (V+ or V-), with or without statocysts (S+ or S-) and freely walking or passively transported on a trolley (P+ or P-). Intact crabs (V+S+P+) show good stabilisation of the eyes in space, the only movements with respect to external coordinates being saccadic resetting movements (fast phases of nystagmus). The eyes thus compensate well for body turns, but are unaffected by translatory movements of the body and turns that are not accompanied by a change in the orientation of the long axis of the body in space. In the absence of any one sense, compensation for rotation is significantly impaired, whether measured by the increase in the width of the histograms of changes in the angular positions of the eyes in space ( capdelta &phgr; E), by the mean angular velocity of the eyes(slope of regression line, mE) with respect to the angular velocity of the body (mB) or by response gain plotted against angular acceleration of body turn (a). The absence of two senses reduces the crab's ability to compensate still further, with the statocyst-only condition (V-S+P-) being little better than the condition when all three senses are absent(V-S-P-).Such multisensory control of eye compensation for body rotation is discussed both in terms of making use of every available cue for reducing retinal slip and in making available the information content of the optic flow field.

Impact of Electric Vehicle Lateral Dynamics on the Battery Pack

2014 ◽  
Vol 590 ◽  
pp. 451-457
Author(s):  
Sen Nan Song ◽  
Fa Chao Jiang ◽  
Hong Shi
Keyword(s):  
Mathematical Model ◽  
Angular Acceleration ◽  
Simulation Software ◽  
The Body ◽  
Battery Pack ◽  
Vehicle Body ◽  
Rolling Motion ◽  
Rolling Angle ◽  
On The Road ◽  
The Mathematical Model

The present work is concerned with the rolling motion of the battery pack when EV travelling on the road. First McPherson suspension system was regarded as the research object with detailed analysis of its structural features and motion characteristics. Establish the mathematical model which could apply to calculating the rolling motion of the vehicle body. Through MATLAB/Simulink simulation software, we could calculate the rolling angle on passive suspension. On this basis, assume that the battery pack mounted on the vehicle body and make it passive connection and PID connection. When the body rolls, the battery pack will produce a certain angle then. Next establish the mathematical model to summarize the relationship between the two variables. Then we set the parameters and calculate the roll angle of battery pack in both cases for comparison. Simulation results show that road irregularities will make battery rotate an angle and PID controller can effectively reduce the angle, especially angular acceleration. This paper put forward a new idea that battery is connected with body by active control on EV, and proves the superiority in reducing the rolling angle.

Direct Kinematic Analysis of a Hexapod Spider-Like Mobile Robot

2011 ◽  
Vol 403-408 ◽  
pp. 5053-5060 ◽  
Author(s):  
Mostafa Ghayour ◽  
Amir Zareei
Keyword(s):  
Angular Velocity ◽  
Mobile Robot ◽  
Time Variation ◽  
Kinematic Analysis ◽  
The Body ◽  
Specific Time ◽  
Centre Of Gravity ◽  
Joint Variable ◽  
Direct Kinematics ◽  
Robot Platform

In this paper, an appropriate mechanism for a hexapod spider-like mobile robot is introduced. Then regarding the motion of this kind of robot which is inspired from insects, direct kinematics of position and velocity of the centre of gravity (C.G.) of the body and noncontact legs are analysed. By planning and supposing a specific time variation for each joint variable, location and velocity of the C.G. of the robot platform and angular velocity of the body are obtained and the results are shown and analysed.

Newtonian flow theory for slender bodies in a dusty gas

1981 ◽  
Vol 108 ◽  
pp. 147-157 ◽  
Author(s):  
R. M. Barron ◽  
J. T. Wiley
Keyword(s):  
Shock Wave ◽  
Gas Flow ◽  
The Body ◽  
Dusty Gas ◽  
Newtonian Theory ◽  
Wedge Surface ◽  
Slender Bodies ◽  
Two Phases ◽  
Flow Variables ◽  
Thin Wedge

Hypersonic small-disturbance theory is extended to consider the problem of dusty-gas flow past thin two-dimensional bodies. The mass fraction of suspended particles is assumed to be sufficiently large that the two-way interaction between particle phase and gas phase must be considered. The system of eight governing equations is further reduced by considering the Newtonian approximation γ → 1 andM∞→ ∞. The Newtonian theory up to second order is studied and the equations are solved for the case of a thin wedge at zero angle of attack. Expressions for the streamlines, dust-particle paths, shock-wave location and all flow variables are obtained. It is seen that the presence of the dust increases the pressure along the wedge surface and tends to bend the shock wave towards the body surface. Other effects of the interaction of the two phases are also discussed.

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