Automatic Generation of Piecewise Constant Speed Motion for Multi-Axis Machines

1992 ◽  
Author(s):  
D. C. H. Yang ◽  
Jui-Jen Chou
Keyword(s):  
General Theory ◽  
Automatic Generation ◽  
Constant Speed ◽  
Manufacturing Processes ◽  
Speed Profile ◽  
Coordinated Motion ◽  
Piecewise Constant ◽  
Smooth Motion ◽  
Path Geometry ◽  
The Given

Abstract This paper presents a general theory on the generation of smooth motion profiles for the coordinated motion of multi-axis manipulators with orthogonal regional structures. Motion with constant speed is important and required in many manufacturing processes, such as milling, welding, finishing and painting. In this paper, a piecewise constant speed profile is constructed by a sequence of Hermite cuves to form a composite Hermite curve in parametric domain. Due to the continuity of acceleration in the proposed speed profile, it generates relatively better product quality than traditional techniques. Besides, we also provide a method for the feasibility study of manufacture capability in terms of the given manipulator, the desired path, and the assigned speed. This includes the consideration of manipulator dynamics, actuator limitation, path geometry, jerk constraints and motion kinematics. The result is a general one and is applicable to all curves tracked by multi-axis manipulators with orthogonal regional structures.

Automatic Generation of Piecewise Constant Speed Motion with Smooth Transition for Multi-Axis Machines

1994 ◽  
Vol 116 (2) ◽  
pp. 581-586 ◽  
Author(s):  
D. C. H. Yang ◽  
Jui-Jen Chou
Keyword(s):  
Automatic Generation ◽  
Constant Speed ◽  
Smooth Transition ◽  
Speed Profile ◽  
Piecewise Constant ◽  
Smooth Motion ◽  
Path Geometry ◽  
Five Axes ◽  
The Given ◽  
Motion Profile

This paper presents a general theory on generating a smooth motion profile for the coordinated motion of five-axes CNC/CMM machines. Motion with constat speed is important and required in many manufacturing processes, such as milling, welding, finishing, and painting. In this paper, a piecewise constant speed profile is constructed by a sequence of Hermite curves to form a composite Hermite curve in parametric domain. Given the continuity of acceleration in our proposed speed profile, it generates relatively better product quality than traditional techniques. We also provide a method for the feasibility study of manufacturing capability in terms of the given machine, the desired path, and the assigned speed. We consider machine dynamics, actuator limitation, path geometry, jerk constraints, and motion kinematics.

scholarly journals 3D Digitization and Additive Manufacturing Technologies in Medicine

2018 ◽  
Vol 26 (42) ◽  
pp. 165-170
Author(s):  
Ivan Molnár ◽  
Ladislav Morovič
Keyword(s):  
Additive Manufacturing ◽  
Manufacturing Processes ◽  
Design And Manufacturing ◽  
Medical Aids ◽  
Manufacturing Methods ◽  
Manufacturing Technologies ◽  
Design And Manufacture ◽  
3D Digitization ◽  
The Given

Abstract The paper discusses the use of 3D digitization and additive manufacturing technologies in the field of medicine. In addition, applications of the use of 3D digitization and additive manufacturing methods are described, focusing on the design and manufacture of individual medical aids. Subsequently, the process of designing and manufacturing of orthopedic aids using these technologies is described and the advantages of introducing the given technologies into the design and manufacturing processes in the medicine sector are presented.

scholarly journals Análise crítica da teoria dos direitos humanos na obra de Michel Villey

2019 ◽  
Vol 1 (40) ◽  
Author(s):  
Gustavo Rabay Guerra ◽  
Henrique Jerônimo Bezerra Marcos
Keyword(s):  
Human Rights ◽  
General Theory ◽  
John Locke ◽  
Thomas Hobbes ◽  
Christian Wolff ◽  
Legal Norms ◽  
The Creation ◽  
The Given ◽  
Intrinsic Contradiction ◽  
Do So

RESUMOEste artigo tem por objeto a Teoria dos Direitos Humanos em Michel Villey. Seu objetivo é apresentar uma contestação à alegação de Michel Villey de que os direitos humanos não podem ser considerados Direito. Para tanto, realiza uma apresentação da Teoria dos Direitos Humanos em Michel Villey, passando pela criação dos direitos humanos em Thomas Hobbes, a inversão de objetivos dos direitos humanos em John Locke e a expansão dos direitos humanos em Christian Wolff. Em seguida passa a apresentar a crítica de Michel Villey aos direitos humanos e as falhas deste autor ao realizar suas acusações, haja vista a possibilidade de solução das contradições (colisões) entre os direitos humanos, além de que não se pode confundir o critério de validade da norma com sua eficácia. O trabalho conclui pela juridicidade dos direitos humanos ao demonstrar que a suposta contradição não seria razão para retirar esta qualidade.PALAVRAS-CHAVEFilosofia do Direito. Direitos Humanos. Michel Villey. ABSTRACTThe present work deals with the General Theory of Human Rights in Michel Villey. Its purpose is to present a challenge to Michel Villeys’ claim that human rights are not legal norms. To do so, the text presents the General Theory of Human Rights in Michel Villey, including the creation of human rights by Thomas Hobbes, the changing perspective attributed to John Locke and the numerical expansion of human rights attributed to Christian Wolff. The text then presents Michel Villeys’ critics of human rights and the problems with those critics; specifically, that the given conflicts between norms aren’t sufficient to declare that they aren’t legal norms, other than that, the text points that in his critics Michel Villey confuses the concepts of validity of the norm with its effectiveness. The work concludes that human rights are legal norms and its supposed intrinsic contradiction is not sufficient to withdraw this quality.KEYWORDSPhilosophy of Law. Human Rights. Michel Villey.

scholarly journals Spatially Adaptive Regularization in Image Segmentation

Algorithms ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 226
Author(s):  
Laura Antonelli ◽  
Valentina De Simone ◽  
Daniela di Serafino
Keyword(s):  
Image Segmentation ◽  
Split Bregman ◽  
Minimization Method ◽  
Piecewise Constant ◽  
Median Filters ◽  
Spatial Image ◽  
Local Regularization ◽  
Spatial Features ◽  
Spatially Adaptive ◽  
The Given

We present a total-variation-regularized image segmentation model that uses local regularization parameters to take into account spatial image information. We propose some techniques for defining those parameters, based on the cartoon-texture decomposition of the given image, on the mean and median filters, and on a thresholding technique, with the aim of preventing excessive regularization in piecewise-constant or smooth regions and preserving spatial features in nonsmooth regions. Our model is obtained by modifying a well-known image segmentation model that was developed by T. Chan, S. Esedoḡlu, and M. Nikolova. We solve the modified model by an alternating minimization method using split Bregman iterations. Numerical experiments show the effectiveness of our approach.

Coordinated Motion Planning of Legged Mobile Manipulator for Tracking the Given End-Effector’s Trajectory

2019 ◽  
Author(s):  
Kondalarao Bhavanibhatla ◽  
Sulthan Suresh-Fazeela ◽  
Dilip Kumar Pratihar
Keyword(s):  
Motion Planning ◽  
Degrees Of Freedom ◽  
Robotic System ◽  
Simulation Software ◽  
Body Motion ◽  
Whole Body ◽  
Mobile Manipulator ◽  
Coordinated Motion ◽  
Multibody Dynamic ◽  
The Given

Abstract In this paper, a novel algorithm is presented to achieve the coordinated motion planning of a Legged Mobile Manipulator (LMM) for tracking the given end-effector’s trajectory. LMM robotic system can be obtained by mounting a manipulator on the top of a multi-legged platform for achieving the capabilities of both manipulation and mobility. To exploit the advantages of these capabilities, the manipulator should be able to accomplish the task, while the hexapod platform moves simultaneously. In the presented approach, the whole-body motion planning is achieved in two steps. In the first step, the robotic system is assumed to be a mobile manipulator, in which the manipulator has two additional translational degrees of freedom at the base. The redundancy of this robotic system is solved by treating it as an optimization problem. Then, in the second step, the omnidirectional motion of the legged platform is achieved with a combination of straight forward and crab motions. The proposed algorithm is tested through a numerical simulation in MATLAB and then, validated on a virtual model of the robot using multibody dynamic simulation software, MSC ADAMS. Multiple trajectories of the end-effector have been tested and the results show that the proposed algorithm accomplishes the given task successfully by providing a singularity-free whole-body motion.

scholarly journals Mawhin’s Continuation Technique for a Nonlinear BVP of Variable Order at Resonance via Piecewise Constant Functions

2021 ◽  
Vol 5 (4) ◽  
pp. 216
Author(s):  
Shahram Rezapour ◽  
Mohammed Said Souid ◽  
Sina Etemad ◽  
Zoubida Bouazza ◽  
Sotiris K. Ntouyas ◽  
...  
Keyword(s):  
Existence Of Solutions ◽  
Coincidence Degree ◽  
Degree Theory ◽  
Variable Order ◽  
Mawhin’S Continuation Theorem ◽  
Piecewise Constant ◽  
At Resonance ◽  
Piecewise Constant Functions ◽  
The Given ◽  
Continuation Technique

In this paper, we establish the existence of solutions to a nonlinear boundary value problem (BVP) of variable order at resonance. The main theorem in this study is proved with the help of generalized intervals and piecewise constant functions, in which we convert the mentioned Caputo BVP of fractional variable order to an equivalent standard Caputo BVP at resonance of constant order. In fact, to use the Mawhin’s continuation technique, we have to transform the variable order BVP into a constant order BVP. We prove the existence of solutions based on the existing notions in the coincidence degree theory and Mawhin’s continuation theorem (MCTH). Finally, an example is provided according to the given variable order BVP to show the correctness of results.

A theory of electromagnetically driven shock waves

1959 ◽  
Vol 6 (2) ◽  
pp. 289-301 ◽  
Author(s):  
J. K. Wright ◽  
M. C. Black
Keyword(s):  
Shock Wave ◽  
Shock Waves ◽  
General Theory ◽  
Strong Shock ◽  
Constant Speed ◽  
External Circuit ◽  
Initial Value ◽  
Electromagnetic Forces ◽  
Strong Shock Waves ◽  
Final Speed

During the last few years, many experimental devices have been built in which strong shock waves are generated in gases by electromagnetic forces on currentcarrying gas particles. The general theory of these devices is discussed, taking external circuit inductance into account. It is shown that a shock wave of constant speed is finally attained. This shock wave is travelling at 90% of its final speed when the circuit inductance has increased to 3·0 times its initial value.

STEPPER MOTOR SPEED PROFILE GENERATION IN REAL-TIME SYSTEMS

2020 ◽  
pp. 63-71
Author(s):  
N. Provatorov ◽  
I. Ovcharuk
Keyword(s):  
Real Time ◽  
High Speed ◽  
Adaptive Design ◽  
Automatic Generation ◽  
Stepper Motor ◽  
Necessary Condition ◽  
Speed Profile ◽  
Motor Speed ◽  
Production Safety ◽  
Improved Model

With the development and distribution of embedded control systems for industrial and household equipment, the generation of speed trajectories for systems controlled by motors, other rotary mechanisms and units remains an urgent task. Adjusting the acceleration profile improves the quality of the system, and the use of adaptive design of automatic controls theoretically increases the speed of work. Implementation of compulsory software control of the speed profile or its automatic generation, according to the current parameters of the system, reduces the risks associated with the human factor and protects the system from operator inaccuracy. Reducing the factor of undesirable interference and creating a model of controlled environment increases the level of production safety, therefore, improving and modernizing the existing approach to managing high-speed industrial systems is a necessary condition for its further development. This article proposes to consider an improved model of a software speed controller that controls the pulse driver of a stepper motor. Based on existing research and corporate solutions during production development used experimentally the adaptive design of the state machine of the system, makes it possible to vary the speed of rotation of the stepper motor during the operation of the system in real time.

Deterministic Local Conversion of Incomparable States by Collective LOCC

2005 ◽  
Vol 5 (3) ◽  
pp. 247-257
Author(s):  
I. Chattopadhyay ◽  
D. Sarkar
Keyword(s):  
General Theory ◽  
Finite Number ◽  
Entangled States ◽  
Entangled State ◽  
Input State ◽  
Schmidt Rank ◽  
Maximally Entangled States ◽  
The Given ◽  
Lower Dimensional

Incomparability of pure bipartite entangled states under deterministic LOCC is a very strange phenomena. We find two possible ways of getting our desired pure entangled state which is incomparable with the given input state, by collective LOCC with certainty. The first one is by providing some pure entanglement through the lower dimensional maximally-entangled states or using further less amount of entanglement and the next one is by collective operation on two pairs which are individually incomparable. It is quite surprising that we are able to achieve maximally entangled states of any Schmidt rank from a finite number of 2x2 pure entangled states only by deterministic LOCC. We provide general theory for the case of 3x3 system of incomparable states by the above processes where incomparability seems to be the most hardest one.

scholarly journals Processing of Targets in Smooth or Apparent Motion Along the Vertical in the Human Brain: An fMRI Study

2010 ◽  
Vol 103 (1) ◽  
pp. 360-370 ◽  
Author(s):  
Vincenzo Maffei ◽  
Emiliano Macaluso ◽  
Iole Indovina ◽  
Guy Orban ◽  
Francesco Lacquaniti
Keyword(s):  
Apparent Motion ◽  
Visual Motion ◽  
Brain Activity ◽  
Activity Patterns ◽  
Vertical Motion ◽  
Constant Speed ◽  
Lingual Gyrus ◽  
Fmri Study ◽  
Smooth Motion ◽  
The Right

Neural substrates for processing constant speed visual motion have been extensively studied. Less is known about the brain activity patterns when the target speed changes continuously, for instance under the influence of gravity. Using functional MRI (fMRI), here we compared brain responses to accelerating/decelerating targets with the responses to constant speed targets. The target could move along the vertical under gravity (1 g), under reversed gravity (−1 g), or at constant speed (0 g). In the first experiment, subjects observed targets moving in smooth motion and responded to a GO signal delivered at a random time after target arrival. As expected, we found that the timing of the motor responses did not depend significantly on the specific motion law. Therefore brain activity in the contrast between different motion laws was not related to motor timing responses. Average BOLD signals were significantly greater for 1 g targets than either 0 g or −1 g targets in a distributed network including bilateral insulae, left lingual gyrus, and brain stem. Moreover, in these regions, the mean activity decreased monotonically from 1 g to 0 g and to −1 g. In the second experiment, subjects intercepted 1 g, 0 g, and −1 g targets either in smooth motion (RM) or in long-range apparent motion (LAM). We found that the sites in the right insula and left lingual gyrus, which were selectively engaged by 1 g targets in the first experiment, were also significantly more active during 1 g trials than during −1 g trials both in RM and LAM. The activity in 0 g trials was again intermediate between that in 1 g trials and that in −1 g trials. Therefore in these regions the global activity modulation with the law of vertical motion appears to hold for both RM and LAM. Instead, a region in the inferior parietal lobule showed a preference for visual gravitational motion only in LAM but not RM.

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