scholarly journals Kinematic Synthesis Using Reinforcement Learning

2018 ◽  
Author(s):  
Kaz Vermeer ◽  
Reinier Kuppens ◽  
Justus Herder
Keyword(s):  
Reinforcement Learning ◽  
Path Generation ◽  
Two Dimensional ◽  
Kinematic Synthesis ◽  
Prior Art ◽  
Straight Line ◽  
Feature Based ◽  
Kinematic Mechanisms ◽  
Straight Line Mechanism ◽  
Kinematic Simulations

The presented research demonstrates the synthesis of two-dimensional kinematic mechanisms using feature-based reinforcement learning. As a running example the classic challenge of designing a straight-line mechanism is adopted: a mechanism capable of tracing a straight line as part of its trajectory. This paper presents a basic framework, consisting of elements such as mechanism representations, kinematic simulations and learning algorithms, as well as some of the resulting mechanisms and a comparison to prior art. Series of successful mechanisms have been synthesized for path generation of a straight line and figure-eight.

Development of a Compliant Rotary-to-Translational Transmission Mechanism for a Micro-Parallel Kinematic Mechanism

2008 ◽  
Author(s):  
Jessica R. Bronson ◽  
Gloria J. Wiens ◽  
Irene Fassi
Keyword(s):  
Translational Motion ◽  
Integrated Design ◽  
Flexible Beams ◽  
Embedded Sensing ◽  
Rotary Actuator ◽  
Straight Line ◽  
Parallel Kinematic ◽  
Kinematic Mechanisms ◽  
Straight Line Mechanism ◽  
Crank Mechanism

This paper presents the integrated design of an electrostatic comb-drive rotary actuator and a compliant slider-crank mechanism to transmit the motion from a rotary actuator into translational motion. This integrated design yields a transmission exhibiting minimal sliding contact with supporting substrate. This design is applicable to micro-Parallel Kinematic Mechanisms (PKM) for micro/nano positioning and manipulation of optical components including lenses and mirrors. For a 3 degree of freedom micro-PKM, the rotational motion of three electrostatic torsion actuators is converted into translational motion through a compliant transmission device. The compliant transmission is based on a slider-crank mechanism that uses flexible beams for the linkages. The input of the rotary motion through the transmission’s crank yields translational motion of the slider component. The slider is supported via a Roberts straight-line mechanism which yields a suspended slider design and therefore reduced friction and wear within the transmission. Furthermore, the slider component of the transmission provides a linear force-displacement relationship beneficial for embedded sensing. This paper describes the design of the actuation and transmission system and its integration into the kinematics of the micro PKM motion.

Kinematic Synthesis of Adjustable Mechanisms—Part 2: Path Generation

1973 ◽  
Vol 95 (2) ◽  
pp. 423-429 ◽  
Author(s):  
Joseph F. McGovern ◽  
George N. Sandor
Keyword(s):  
Closed Form ◽  
Higher Order ◽  
Complex Numbers ◽  
Path Generation ◽  
Function Generator ◽  
Kinematic Synthesis ◽  
Closed Form Solutions ◽  
Straight Line ◽  
Adjustable Mechanisms

A method utilizing complex numbers similar to that used in Part 1 for adjustable function generator synthesis is applied to the synthesis of adjustable path generators. Finitely separated path points with prescribed timing as well as higher order approximations (infinitesimally separated path points) are treated, by way of analytical and closed form solutions. Adjustment of the path generator mechanism is accomplished by moving a fixed pivot. Mechanisms adjustable for different approximate straight line motions, for various path curvatures, and path tangents as well as several arbitrary paths can be synthesized. Four-bar and geared five-bar mechanisms are considered. Examples are included describing synthesized mechanisms.

A modified tangent-gas approximation for two-dimensional steady flow

1958 ◽  
Vol 4 (6) ◽  
pp. 600-606 ◽  
Author(s):  
G. Power ◽  
P. Smith
Keyword(s):  
Least Squares ◽  
Steady Flow ◽  
Variational Approach ◽  
Least Squares Method ◽  
Two Dimensional ◽  
Subsonic Flows ◽  
Von Karman ◽  
Straight Line ◽  
Volume Relationship ◽  
Pressure Volume Relationship

A set of two-dimensional subsonic flows past certain cylinders is obtained using hodograph methods, in which the true pressure-volume relationship is replaced by various straight-line approximations. It is found that the approximation obtained by a least-squares method possibly gives best results. Comparison is made with values obtained by using the von Kármán-Tsien approximation and also with results obtained by the variational approach of Lush & Cherry (1956).

KNOT POINTS IN TWO-DIMENSIONAL MAPS AND RELATED PROPERTIES

2009 ◽  
Vol 19 (02) ◽  
pp. 545-555 ◽  
Author(s):  
F. TRAMONTANA ◽  
L. GARDINI ◽  
D. FOURNIER-PRUNARET ◽  
P. CHARGE
Keyword(s):  
Focal Point ◽  
Singular Line ◽  
Two Dimensional ◽  
Focal Points ◽  
Singular Set ◽  
One Dimensional ◽  
Attracting Set ◽  
Straight Line ◽  
Special Character ◽  
Stable And Unstable Sets

We consider the class of two-dimensional maps of the plane for which there exists a whole one-dimensional singular set (for example, a straight line) that is mapped into one point, called a "knot point" of the map. The special character of this kind of point has been already observed in maps of this class with at least one of the inverses having a vanishing denominator. In that framework, a knot is the so-called focal point of the inverse map (it is the same point). In this paper, we show that knots may also exist in other families of maps, not related to an inverse having values going to infinity. Some particular properties related to focal points persist, such as the existence of a "point to slope" correspondence between the points of the singular line and the slopes in the knot, lobes issuing from the knot point and loops in infinitely many points of an attracting set or in invariant stable and unstable sets.

Space-time processing for «range – azimuth – elevation» measurements in non-cooperative systems of radars with phased array antennas

2021 ◽  
Author(s):  
V.V. Chapursky ◽  
A.A. Filatov ◽  
D.E. Koroteev
Keyword(s):  
Phased Array ◽  
Elevation Angle ◽  
Two Dimensional ◽  
Time Processing ◽  
Correlation Integral ◽  
Phased Array Antennas ◽  
Array Antennas ◽  
Straight Line Parallel ◽  
Straight Line ◽  
Line Parallel

The methods of measuring the three coordinates of an aircraft in the takeoff and landing mode on the runway of airfields based on the use of non - cooperative two-and three-position systems of radars with phased array antennas are considered. For these variants, general analytical expressions are obtained for the complex generalized correlation integral of space – time processing in the function of spatial coordinates, taking into account the individual directional pattern of phased array antennas. On the basis of two – dimensional profiles of the correlation integral modules «range – elevation» and «azimuth – elevation», examples of comparing particular variants of two-position and three-position systems of radars with their location on one straight line parallel runway are given. In conditions of large signal-to-noise ratios, power-law nonlinear transformations of the correlation integral correlation integral module are applied to reduce the level of side lobes in the two – dimensional sections «range – elevation» and «azimuth – elevation». The following results are obtained using examples. Two-dimensional diagrams of the correlation integral module «range – elevation» do not depend on the azimuth of the aircraft in the range of azimuth values β=0…10 ̊ and correctly display the angle of elevation and the range of the aircraft when 2…3 radars of a non-cooperative system are located on the straight line parallel runway. The two-dimensional diagrams of the correlation integral module «azimuth – elevation angle» have an interference structure, and the number and level of their side lobes increase with increasing azimuth of the aircraft. With azimuth β≥10 ̊, this can lead to ambiguity in the measurement of the azimuth and uncertainty in the elevation angle . One of the measures to reduce the side level of the diagrams of the correlation integral module can be the use of a power-law transformation of normalized diagrams exponentiation of degree 3...4. An increase in the number of radars from two to three when they are located on one straight line parallel to the runway led to a decrease in the side lobes level of the «range – elevation angle» and «azimuth – elevation angle» diagrams. In this case, it may be advisable to solve the problem of optimal choice of the position of the intermediate radar on the same straight line. Calculations were also carried out for an additional example of the location of the intermediate radar of a 3-position system with its removal from the base line. At the same time, there was an increase of the side lobes level in the «azimuth – elevation angle» sections, which in the future may require additional research in terms of optimizing the placement of the radars in horizontal plane for such a radar systems.

Optimum Design of Straight-Walled Diffusers

1959 ◽  
Vol 81 (3) ◽  
pp. 321-329 ◽  
Author(s):  
S. J. Kline ◽  
D. E. Abbott ◽  
R. W. Fox
Keyword(s):  
Flow Regimes ◽  
Literature Survey ◽  
Geometrical Parameters ◽  
Two Dimensional ◽  
Constant Ratio ◽  
Straight Line ◽  
Throat Width ◽  
Transformation Of Variables ◽  
Optimum Recovery ◽  
Future Reference

The four common optimum problems in diffuser design are defined. These optima are located in relation to the over-all flow regimes in terms of geometrical parameters for straight-walled units. Using an empirically derived transformation of variables between the conical and two-dimensional geometries, all available data for optimum recovery at constant ratio of wall length to throat width are correlated by a single straight line. This line lies slightly above and parallel to the line of onset of large transitory stall on the chart of over-all flow regimes. The correlated results are based on a literature survey. The range of conditions for each investigation is tabulated for convenient future reference.

scholarly journals Monocular mechanisms determine plaid motion coherence

1996 ◽  
Vol 13 (4) ◽  
pp. 615-626 ◽  
Author(s):  
David Alais ◽  
Maarten J. van der Smagt ◽  
Frans A. J. Verstraten ◽  
W. A. van de Grind
Keyword(s):  
Cortical Area ◽  
The Other ◽  
Coherent Motion ◽  
Spatial Period ◽  
Two Dimensional ◽  
Middle Temporal ◽  
Spatial Frequencies ◽  
Motion Coherence ◽  
Plaid Motion ◽  
Feature Based

AbstractAlthough the neural location of the plaid motion coherence process is not precisely known, the middle temporal (MT) cortical area has been proposed as a likely candidate. This claim rests largely on the neurophysiological findings showing that in response to plaid stimuli, a subgroup of cells in area MT responds to the pattern direction, whereas cells in area V1 respond only to the directions of the component gratings. In Experiment 1, we report that the coherent motion of a plaid pattern can be completely abolished following adaptation to a grating which moves in the plaid direction and has the same spatial period as the plaid features (the so-called “blobs”). Interestingly, we find this phenomenon is monocular: monocular adaptation destroys plaid coherence in the exposed eye but leaves it unaffected in the other eye. Experiment 2 demonstrates that adaptation to a purely binocular (dichoptic) grating does not affect perceived plaid coherence. These data suggest several conclusions: (1) that the mechanism determining plaid coherence responds to the motion of plaid features, (2) that the coherence mechanism is monocular, and thus (3), that it is probably located at a relatively low level in the visual system and peripherally to the binocular mechanisms commonly presumed to underlie two-dimensional (2-D) motion perception. Experiment 3 examines the spatial tuning of the monocular coherence mechanism and our results suggest it is broadly tuned with a preference for lower spatial frequencies. In Experiment 4, we examine whether perceived plaid direction is determined by the motion of the grating components or the features. Our data strongly support a feature-based model.

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