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.

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.

Paraconsistent Reasoning in Cops and Robber Game with Uncertain Information: A Simulation-Based Analysis

2019 ◽  
Vol 27 (03) ◽  
pp. 429-455
Author(s):  
Jacek Szklarski ◽  
Łukasz Białek ◽  
Andrzej Szałs
Keyword(s):  
Paraconsistent Logic ◽  
Smooth Transition ◽  
Uncertain Information ◽  
Paraconsistent Reasoning ◽  
Novel Approach ◽  
Simulation Based ◽  
Real World Applications ◽  
The Given ◽  
Random Failures ◽  
Cops And Robber

We apply a non-classical four-valued logic in the process of reasoning regarding strategies for cops in a modified game of “Cops and Robber” played on a graph. We extend the game by introducing uncertainty in a form of random failures of detecting devices. This is realized by allowing that a robber can be detected in a node only with the given probability PA. Additionally, with the probability PF, cops can be given a false-positive, i.e., they are informed that the robber is located at some node, whereas it is located somewhere else. Consequently, non-zero PFintroduces a measurement noise into the system. All the cops have access to information provided by the detectors and can communicate with each other, so they can coordinate the search. By adjusting the number of detectors, PA, and PFwe can achieve a smooth transition between the two well-known variants of the game: “with fully visible robber” and “with invisible robber”. We compare a simple probabilistic strategy for cops with the non-parametric strategy based on reasoning with a four-valued paraconsistent logic. It is shown that this novel approach leads to a good performance, as measured by the required mean catch-time. We conclude that this type of reasoning can be applied in real-world applications where there is no knowledge about the underlying source of errors which is particularly useful in robotics.

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.

Software Design of Micromouse Motion Control

2014 ◽  
Vol 602-605 ◽  
pp. 989-992
Author(s):  
Hao Ming Zhang ◽  
Lian Soon Peh ◽  
Ying Hai Wang
Keyword(s):  
Motion Control ◽  
Software Design ◽  
Autonomous Robot ◽  
Robot Motion ◽  
Pd Controller ◽  
Detailed Design ◽  
Smooth Motion ◽  
Motion Profile

Micromouse is a small autonomous robot, which must navigate itself through an unknown maze from the start to the destination.One of the main challenges for micromouse is to control its two motors, which are used to control micromouse’s motion in solving the maze. Detailed design of an improved PD controller is given,which has to update the velocity and acceleration values of the motors when it wants to control the robot. Motion profile generator and motion command execution routine is designed to output a smooth motion for the robots.

scholarly journals Study on Acc/Dec Algorithm Based on Piecewise Polynomial in CNC

2011 ◽  
Vol 2-3 ◽  
pp. 43-47 ◽  
Author(s):  
Guo Shun Ji ◽  
Zhi Ping Chen ◽  
Ju Yong Zhang ◽  
Wei Liu
Keyword(s):  
High Speed ◽  
Large Scale ◽  
Polynomial Function ◽  
Tracking Accuracy ◽  
Feedrate Planning ◽  
Smooth Motion ◽  
Planning Algorithm ◽  
S Curve ◽  
The Stability ◽  
Motion Profile

In order to improve the stability of feed movement in high speed CNC system, the feedrate planning algorithm based on piece-wise polynomial function was proposed. The flexible transition of feedrate was realized through maintaining linear continuous jerk. The principle of the proposed algorithm was introduced and the method to generate smooth motion profile based on the proposed algorithm was presented. The rapidity, stability and tracking accuracy of the feedrate planning algorithm to linearity, S curve and the proposed one were analyzed. The proposed algorithm is simple and it can be applied in acceleration/deceleration before interpolation in high speed feed movement to improve the stability of it. The proposed algorithm was applied in multi-contour high speed processing and the result indicated that it could improve the stability of large-scale parts 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.

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.

scholarly journals Study on acc/dec Algorithm Based on Piece-Wise Polynomial in CNC

2013 ◽  
Vol 753-755 ◽  
pp. 1790-1794
Author(s):  
Guo Shun Ji
Keyword(s):  
High Speed ◽  
Large Scale ◽  
Polynomial Function ◽  
Cnc System ◽  
Feedrate Planning ◽  
Smooth Motion ◽  
Planning Algorithm ◽  
The Stability ◽  
Motion Profile

In order to improve the stability of feed movement in high speed CNC system, the feedrate planning algorithm based on piece-wise polynomial function was proposed. The flexible transition of feedrate was realized through maintaining linear continuous jerk. The principle of the proposed algorithm was introduced and the method to generate smooth motion profile based on the proposed algorithm was presented. The proposed algorithm is simple and it can be applied in acceleration/deceleration before interpolation in high speed feed movement to improve the stability of it. The proposed algorithm was applied in multi-contour high speed processing and the result indicated that it could improve the stability of large-scale parts motion.

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.

scholarly journals The mechanical efficiency of frog’s muscle

1939 ◽  
Vol 127 (849) ◽  
pp. 434-451 ◽  
Keyword(s):  
Mechanical Efficiency ◽  
Constant Speed ◽  
Maximum Work ◽  
The Given

The factors determining the maximum work and the mechanical efficiency of muscle were discussed by Hartree and Hill in 1928. Work was measured with the Levin-Wyman ergometer (Levin and Wyman 1927), the muscle being allowed to shorten at constant speed, adjustable as required, and recording a tension-length curve on a smoked surface. The whole of the work which the muscle can do in a single shortening at the given speed is thus obtained, as in no other method. The mechanical efficiency, therefore, should be the highest possible.

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