Journal articles: 'Trajectory of motion'

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Kuwahara, M., T. Sato, and Y. Yotsumoto. "Wriggling motion trajectory illusion." Journal of Vision 12, no. 12 (November 8, 2012): 4. http://dx.doi.org/10.1167/12.12.4.

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Yotsumoto, Y., M. Kuwahara, and T. Sato. "Wriggling Motion Trajectory Illusion." Journal of Vision 12, no. 9 (August 10, 2012): 1234. http://dx.doi.org/10.1167/12.9.1234.

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Beh, Jounghoon, David Han, and Hanseok Ko. "Rule-based trajectory segmentation for modeling hand motion trajectory." Pattern Recognition 47, no. 4 (April 2014): 1586–601. http://dx.doi.org/10.1016/j.patcog.2013.11.010.

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Lee, Eunsung, Eunjung Chae, Hejin Cheong, and Joonki Paik. "Fast Motion Deblurring Using Sensor-Aided Motion Trajectory Estimation." Scientific World Journal 2014 (2014): 1–7. http://dx.doi.org/10.1155/2014/649272.

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This paper presents an image deblurring algorithm to remove motion blur using analysis of motion trajectories and local statistics based on inertial sensors. The proposed method estimates a point-spread-function (PSF) of motion blur by accumulating reweighted projections of the trajectory. A motion blurred image is then adaptively restored using the estimated PSF and spatially varying activity map to reduce both restoration artifacts and noise amplification. Experimental results demonstrate that the proposed method outperforms existing PSF estimation-based motion deconvolution methods in the sense of both objective and subjective performance measures. The proposed algorithm can be employed in various imaging devices because of its efficient implementation without an iterative computational structure.

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Wu, Chi-haur, and Chi-cheng Jou. "Design of a Controlled Spatial Curve Trajectory for Robot Manipulations." Journal of Dynamic Systems, Measurement, and Control 113, no. 2 (June 1, 1991): 248–58. http://dx.doi.org/10.1115/1.2896372.

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For integrating different constraints from robot’s tasks, such as geometry, kinematics, and dynamics, with trajectory planning and robot motion control, a two-layer robot trajectory planning structure is proposed. The structure decomposes the trajectory planning problem into path geometry planning and motion speed planning. By separating speed planning from path geometry planning, two different problems can be solved. The first problem is to incorporate geometric changes of a robot task into both translational and orientational path plannings. By solving it, various spatial curve paths can be planned and the difficulty of predicting rotational motions in the Cartesian space can be removed. The second problem is to incorporate motion constraints into the trajectory planning, such as the constraint of maintaining a desired constant robot speed along any planned geometric path. Through the proposed structure, different robot motion requirements along various spatial curves can be controlled by different speed control functions. To demonstrate the proposed scheme, examples are given.

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Tremblay, Louis-Francis Y., Marc Arsenault, and Meysar Zeinali. "Development of a trajectory planning algorithm for a 4-DoF rockbreaker based on hydraulic flow rate limits." Transactions of the Canadian Society for Mechanical Engineering 44, no. 4 (December 1, 2020): 501–10. http://dx.doi.org/10.1139/tcsme-2019-0173.

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In this paper, a novel trajectory planning methodology is proposed for use within a semi-automated hydraulic rockbreaker system. The objective of the proposed method is to minimize the trajectory duration while hydraulic fluid flow rate limits are respected. Within the trajectory planning methodology, a point-to-point path planning approach based on the decoupling of the motion of the rockbreaker’s first joint is compared with an alternative approach based on Cartesian straight-line motion. Each of these path types is parameterized as a function of time based on an imposed trajectory profile that ensures smooth rockbreaker motions. A constrained nonlinear optimization problem is formulated and solved with the trajectory duration as the objective function while constraints are applied to ensure that flow rate limits through the rockbreaker’s proportional valves and hydraulic pump are not exceeded. The proposed methodology is successfully implemented to compute a set of representative trajectories, with the path planning approach based on the decoupling of the motion of the rockbreaker’s first joint consistently producing shorter trajectory durations.

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Kramer, Steven N., and Richard L. Curran. "Development of the Tri-Level Variable Rate Trajectory With Discretely Vanishing Shock for Optimum Design." Journal of Mechanisms, Transmissions, and Automation in Design 110, no. 1 (March 1, 1988): 88–92. http://dx.doi.org/10.1115/1.3258911.

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The tri-level variable rate trajectory is a general motion which can be applied to programmable controllers, robotic manipulators, mechanisms, and mechanical devices where the input crank orientation, velocity, and acceleration vary with time. In the work presented here, the tri-level variable rate trajectory is an extension of the variable-rate trans-symmetric motion developed by the first author in 1984. That motion and the one developed here consist of discrete segments of constant and linearly varying accelerations occurring over specified time intervals, thereby providing versatile programmable trajectories with several advantages over the constant acceleration motion, simple harmonic motion, cycloidal motion, and the popular polynomial trajectories used in robotics. The tri-level variable-rate trajectory allows much more control of the acceleration contour of the motion and as a result, there is a decrease in the power required, a decrease in the operating cost, and a decrease in dynamic responses such as shock, vibration, and shaking force and virtual elimination of the overshoot problem that sometimes accompanies the polynomial segment motions. This is a general method which can be applied to many applications. The results of applying this trajectory to a complex machine controller are presented as an example.

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Popov, I. P. "COMBINATION OF CIRCULAR MOTIONS IN MACHINES AND MECHANISMS." Frontier materials & technologies, no. 4 (2021): 48–56. http://dx.doi.org/10.18323/2782-4039-2021-4-48-56.

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In technical systems, including aviation and space technology, and in particular, in aircraft transmissions, bearings, orbital systems, helicopter mechanisms, and many others, the combined rotational movements are widespread, and when designing, it is important to understand the nature of joint motion. The paper aimed at the generalization of the principle of the combination of motions in circular movements. The author considered the x'0'y' coordinate system that rotates in the x0y coordinate system without angular acceleration with the velocity ω. The radius of rotation is equal to ρ1. Wherein 0x || 0'x', 0y || 0'y'. An object a rotates in the x'0'y' coordinate system without angular acceleration with the velocity ±ω. The radius of rotation is equal to ρ2. The study identified that at reverse rotations, the trajectory of joint motion represents an ellipse. The author determined all standard ellipse characteristics relating to the case under the study and identified the elliptical trajectory inclination. The study shows that if the joint motion trajectory is elliptical and the semi-axes are equal (ρ1+ρ2) and |ρ1−ρ2|, then an object a undergoes circular motion in the x'0'y' coordinate system without angular acceleration with the velocity −ω. Just as the result of the superposition of two non-accelerated straight movements is also non-accelerated, i.e. a uniform and rectilinear movement, at the one-way rotations, the joint motion trajectory represents a circle. At circular motions with multiple speeds, the joint motion trajectory represents a snail. The practical aspect of the study is determined by the fact that the resulting formulas can be directly used in the CAD system when performing design works.

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Putov, V., V. Sheludko, A. Putov, N. Thang, and M. Kopichev. "Manipulation Robots’ Trajectory Motion Adaptive Control." Procedia Computer Science 150 (2019): 279–86. http://dx.doi.org/10.1016/j.procs.2019.02.053.

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Barata, Catarina, Jacinto C. Nascimento, João M. Lemos, and Jorge S. Marques. "Sparse motion fields for trajectory prediction." Pattern Recognition 110 (February 2021): 107631. http://dx.doi.org/10.1016/j.patcog.2020.107631.

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Watamaniuk, Scott N. J. "The predictive power of trajectory motion." Vision Research 45, no. 24 (November 2005): 2993–3003. http://dx.doi.org/10.1016/j.visres.2005.07.027.

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ISHII, Junko, Yoshito TANAKA, Isao YOKOMICHI, and Shinya OKUDA. "Digital Motion Trajectory on Parallel Mechanisms." Proceedings of Conference of Kyushu Branch 2004.57 (2004): 407–8. http://dx.doi.org/10.1299/jsmekyushu.2004.57.407.

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Miroshnik, Iliya V., and Sergey A. Chepinsky. "Trajectory motion control of underactuated manipulators." IFAC Proceedings Volumes 36, no. 17 (September 2003): 105–10. http://dx.doi.org/10.1016/s1474-6670(17)33377-3.

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Rudenko, Andrey, Luigi Palmieri, Michael Herman, Kris M. Kitani, Dariu M. Gavrila, and Kai O. Arras. "Human motion trajectory prediction: a survey." International Journal of Robotics Research 39, no. 8 (June 7, 2020): 895–935. http://dx.doi.org/10.1177/0278364920917446.

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With growing numbers of intelligent autonomous systems in human environments, the ability of such systems to perceive, understand, and anticipate human behavior becomes increasingly important. Specifically, predicting future positions of dynamic agents and planning considering such predictions are key tasks for self-driving vehicles, service robots, and advanced surveillance systems. This article provides a survey of human motion trajectory prediction. We review, analyze, and structure a large selection of work from different communities and propose a taxonomy that categorizes existing methods based on the motion modeling approach and level of contextual information used. We provide an overview of the existing datasets and performance metrics. We discuss limitations of the state of the art and outline directions for further research.

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Osa, Takayuki. "Multimodal trajectory optimization for motion planning." International Journal of Robotics Research 39, no. 8 (June 4, 2020): 983–1001. http://dx.doi.org/10.1177/0278364920918296.

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Existing motion planning methods often have two drawbacks: (1) goal configurations need to be specified by a user, and (2) only a single solution is generated under a given condition. In practice, multiple possible goal configurations exist to achieve a task. Although the choice of the goal configuration significantly affects the quality of the resulting trajectory, it is not trivial for a user to specify the optimal goal configuration. In addition, the objective function used in the trajectory optimization is often non-convex, and it can have multiple solutions that achieve comparable costs. In this study, we propose a framework that determines multiple trajectories that correspond to the different modes of the cost function. We reduce the problem of identifying the modes of the cost function to that of estimating the density induced by a distribution based on the cost function. The proposed framework enables users to select a preferable solution from multiple candidate trajectories, thereby making it easier to tune the cost function and obtain a satisfactory solution. We evaluated our proposed method with motion planning tasks in 2D and 3D space. Our experiments show that the proposed algorithm is capable of determining multiple solutions for those tasks.

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ONO, Kyosuke, Atushi IMADU, and Toshiyuki SAKAI. "Optimal Motion Trajectory of Giant Swing." Transactions of the Japan Society of Mechanical Engineers Series C 62, no. 599 (1996): 2640–47. http://dx.doi.org/10.1299/kikaic.62.2640.

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Ni, Yubo, Feng Liu, Yi Wu, and Xiangjun Wang. "Continuous-Time Fast Motion of Explosion Fragments Estimated by Bundle Adjustment and Spline Representation Using HFR Cameras." Applied Sciences 11, no. 6 (March 17, 2021): 2676. http://dx.doi.org/10.3390/app11062676.

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This paper introduces a continuous-time fast motion estimation framework using high frame-rate cameras. To recover the high-speed motions trajectory, we inherent the bundle adjustment using a different frame-rate strategy. Based on the optimized trajectory, a cubic B-spline representation was proposed to parameter the continuous-time position, velocity and acceleration during this fast motion. We designed a high-speed visual system consisting of the high frame-rate cameras and infrared cameras, which can capture the fast scattered motion of explosion fragments and evaluate our method. The experiments show that bundle adjustment can greatly improve the accuracy and stability of the trajectory estimation, and the B-spline representation of the high frame-rate can estimate the velocity, acceleration, momentum and force of each fragments at any given time during its motion. The related estimated result can achieve under 1% error.

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Li, Z., T. Yang, and Z. Feng. "Re-entry guidance method based on decoupling control variables and waypoint." Aeronautical Journal 123, no. 1262 (April 2019): 523–35. http://dx.doi.org/10.1017/aer.2019.4.

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ABSTRACTGenerally, earth rotating and non-spherical perturbation of the earth in re-entry motion model are simplified using the standard trajectory guidance method. The re-entry motion is also simplified to horizontal motion and vertical motion and controlled, respectively. The simplification of re-entry motion model will lead to loss of motion accuracy and location accuracy. The direct decomposition will lead to the reduction of control accuracy because the horizontal motion and the vertical motion are coupled in re-entry. To improve the standard trajectory guidance method, the standard trajectory guidance method based on decoupling control variables and waypoint is proposed in this paper. The proposed guidance method will not simplify earth rotating and non-spherical perturbation of the earth in motion equation or decompose the re-entry motion to horizontal motion and vertical motion. Trajectory waypoint is adopted to reduce the change frequency of tracking states, because tracking states change frequently if the entire standard trajectory is tracked in real time.

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Yang, Jianyu, Y. F. Li, Keyi Wang, Yuan Wu, Giuseppe Altieri, and Massimo Scalia. "Mixed Signature: An Invariant Descriptor for 3D Motion Trajectory Perception and Recognition." Mathematical Problems in Engineering 2012 (2012): 1–29. http://dx.doi.org/10.1155/2012/613939.

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Motion trajectory contains plentiful motion information of moving objects, for example, human gestures and robot actions. Motion perception and recognition via trajectory are useful for characterizing them and a flexible descriptor of motion trajectory plays important role in motion analysis. However, in the existing tasks, trajectories were mostly used in raw data and effective descriptor is lacking. In this paper, we present a mixed invariant signature descriptor with global invariants for motion perception and recognition. The mixed signature is viewpoint invariant for local and global features. A reliable approximation of the mixed signature is proposed to reduce the noise in high-order derivatives. We use this descriptor for motion trajectory description and explore the motion perception with DTW algorithm for salient motion features. To achieve better accuracy, we modified the CDTW algorithm for trajectory matching in motion recognition. Furthermore, a controllable weight parameter is introduced to adjust the global features for tasks in different circumstances. The conducted experiments validated the proposed method.

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Lee, JiYong, YoungEun Kim, and SangHun Nam. "Motion Capture based Taekwondo Motion Trajectory Visualization Media Art Technique." Journal of Digital Art Engineering and Multimedia 6, no. 1 (June 30, 2019): 1–8. http://dx.doi.org/10.29056/idaem.2019.06.04.

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Bolcu, Dumitru, Marius Marinel Stănescu, Cosmin Mihai Miriţoiu, and Cristian Oliviu Burada. "Study about the Vehicle Orientation on the Trajectory during Transient Movements." Applied Mechanics and Materials 822 (January 2016): 68–73. http://dx.doi.org/10.4028/www.scientific.net/amm.822.68.

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In this paper, it is deduced the ordinary differential equation that results in angle variation between the vehicle mass centre rate and the vehicle fore-aft axis. There are presented the wheels turning angles variations dependent on the angle that gives the vehicle orientation on trajectory. There are studied the following cases: the transfer from linear to circular motion, the transfer from circular to linear motion and the movement amidst poles. For each of these motions, there are presented the vehicle orientation angle variations on trajectory for three distinct rates. It is also presented the travelling rate influence on how the vehicle is situated on trajectory.

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Slota, Adam. "Bezier Curve Based Programmed Trajectory for Coordinated Motion of Two Robots in Cartesian Space." Applied Mechanics and Materials 555 (June 2014): 192–98. http://dx.doi.org/10.4028/www.scientific.net/amm.555.192.

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Coordinated motion of two robots in Cartesian space is considered in the paper. The goal is to generate trajectories for which change of distance between points on trajectories during motion is minimal. To minimize relative position errors along trajectories an idea of corrective motion is introduced. Trajectory coordinates are calculated as the sum of programmed and corrective motions. To calculate the speed vector of the programmed motion at the current position, the speed at the closest point on the programmed trajectory is used. The closest point is defined as the one to which the distance from the current position is minimal or the programmed position at given time. In order to attract the generated trajectory to the programmed one a modification of the programmed speed vector is proposed. The described approach is verified in simulation. For simulation experiments programmed trajectories defined by Bezier curve segments are used. Simulations for different shapes of programmed trajectories and different programmed velocity rates are presented.

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Dong, Suge, Daidi Hu, Ruijun Li, and Mingtao Ge. "Human Action Recognition Based on Foreground Trajectory and Motion Difference Descriptors." Applied Sciences 9, no. 10 (May 24, 2019): 2126. http://dx.doi.org/10.3390/app9102126.

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Aimed at the problems of high redundancy of trajectory and susceptibility to background interference in traditional dense trajectory behavior recognition methods, a human action recognition method based on foreground trajectory and motion difference descriptors is proposed. First, the motion magnitude of each frame is estimated by optical flow, and the foreground region is determined according to each motion magnitude of the pixels; the trajectories are only extracted from behavior-related foreground regions. Second, in order to better describe the relative temporal information between different actions, a motion difference descriptor is introduced to describe the foreground trajectory, and the direction histogram of the motion difference is constructed by calculating the direction information of the motion difference per unit time of the trajectory point. Finally, a Fisher vector (FV) is used to encode histogram features to obtain video-level action features, and a support vector machine (SVM) is utilized to classify the action category. Experimental results show that this method can better extract the action-related trajectory, and it can improve the recognition accuracy by 7% compared to the traditional dense trajectory method.

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Tian, Jia Lin, Yun He, Lei Chen, and Ban Wang. "Simulation of Motion Trajectory of Parachute Inflation Process." Advanced Materials Research 945-949 (June 2014): 658–61. http://dx.doi.org/10.4028/www.scientific.net/amr.945-949.658.

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Motion trajectory is the fundamental basis for the design and research of parachute. The fall state, the minimum safe altitude and airborne site are closely associated with the motion trajectory. Particularly due to rapid changes in these parameters such as canopy shape, velocity, dynamic load of the parachute, it is very difficult to determine the motion trajectory of parachute inflation process. Currently, the trajectory is mainly obtained by airdrop tests or wind tunnel tests. The tests are very expensive. Based on the force analysis and mathematical model of a certain type of parachute, we used the computer system to study the motion trajectory of parachute.

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MORITA, SUSUMU. "TRAJECTORY GENERATION BETWEEN TWO ARBITRARY STATES BASED ON HAMILTON'S PRINCIPLE A VARIABLE SUBSTITUTION METHOD." International Journal of Humanoid Robotics 09, no. 03 (September 2012): 1250023. http://dx.doi.org/10.1142/s0219843612500235.

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Motion principles of animals and humans has been a field of interest for over half a century. As for human motions, the study by modern science started off by a Soviet physiologist in the 1930's, followed by many proposals of models and principles to explain how human beings move. This paper introduces an alternative motion principle with a motion generation method. The subject in discussion is the Hamilton's principle which yields equation of free motion. The motion generation method is derived based on a novel variable substitution to be applied to the Hamilton's principle which then yields the Euler–Lagrange equation that can be used for motion trajectory generation between two arbitrary states. A numerical example with measured data is shown, and a mathematical explanation of the variable substitution and the qualitative meaning of the trajectory generation method is given.

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Li, Yang Hua, Bo Mo, and Jie Zhao. "Missile Trajectory Simulation in Vertical Plane." Applied Mechanics and Materials 527 (February 2014): 167–71. http://dx.doi.org/10.4028/www.scientific.net/amm.527.167.

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In this paper, Newton's laws of motion and momentum theorem are the theoretical basis. The equations of motion in the vertical plane are the calculation basis. In order to get the ballistic and numerical solution of motion parameters of the missile, the Runge-Kutta method and matlab are used to solve the missile Trajectory. Firstly, this paper builds the trajectory model of missile in vertical plane. Secondly, this paper chooses missile control method. Thirdly, the Runge-Kutta method and matlab are used to verify the correctness. And to further analyze the law of motion parameters changed with time.

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Vitalii, Berdyshev. "OBSERVER’S TRAJECTORY TRACKING OBJECT BYPASSING OBSTACLE ON THE SHORTEST CURVE." Eurasian Journal of Mathematical and Computer Applications 9, no. 4 (December 2021): 4–16. http://dx.doi.org/10.32523/2306-6172-2021-9-4-4-16.

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Motion of some object is considered. The object t moves from the initial point t∗ to the final one t ∗ . But since absent of the direct path, he should bypass an obstacle a connected bodily set G. It is supposed that t moves by the most short trajectory T = Tt , and the trajectory T is a convex curve. The observer’s f task is to find the trajectory Tf that provides tracking the object on the most part of the object’s motion and, if possible, the lesser object’s stealth of motion along the trajectory T . The latency is defined by the distance that the observer must pass to see the object in the field of vision. The object and observer start at the same initial instant, and their velocities are equal. In the paper, examples of the trajectories Tf in R 2 are presented, on which the observer can see the object’s trajectory T ; also, the value of the object’s latency is shown for the invisible parts of the trajectory T . The variant of Tf in R 3 is shown.

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Yin, Hai Bin, Ni Cong Jiang, Jin Li Xu, and Feng Yun Huang. "Lower Distortion in Trajectory Planning for a Rigid-Flexible Manipulator Based on PSO Algorithm." Applied Mechanics and Materials 300-301 (February 2013): 458–63. http://dx.doi.org/10.4028/www.scientific.net/amm.300-301.458.

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This paper presents a novel trajectory planning for a multilink rigid-flexible manipulator. An original trajectory is given according to the site condition and requirement of motion, and desired trajectory is determined by using an optimization. To satisfy the requirement of motion with restrictions, the desired trajectory cannot significantly deviate from the original trajectory. Consequently, the lower distortion in trajectory planning should be considered in optimization algorithm. Two different formulations of trajectory are introduced in two optimization algorithms to compare the distortion degree. Finally, the calculation samples are addressed by using specific site conditions and requirements of motion to verify the validity of proposal.

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Gu, Shangding, Chunhui Zhou, Yuanqiao Wen, Changshi Xiao, and Alois Knoll. "Motion Planning for an Unmanned Surface Vehicle with Wind and Current Effects." Journal of Marine Science and Engineering 10, no. 3 (March 14, 2022): 420. http://dx.doi.org/10.3390/jmse10030420.

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Aiming at the problem that unmanned surface vehicle (USV) motion planning is disturbed by effects of wind and current, a USV motion planning method based on regularization-trajectory cells is proposed. First, a USV motion mathematical model is established while considering the influence of wind and current, and the motion trajectory is analyzed. Second, a regularization-trajectory cell library under the influence of wind and current is constructed, and the influence of wind and current on the weight of the search cost is analyzed. Finally, derived from the regularization-trajectory cell and the search algorithm, a motion planning method for a USV that considers wind and current effects is provided. The experimental results indicate that the motion planning is closer to the actual trajectory of a USV in complex environments and that our method is highly practicable.

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HARA, Susumu, Masaki TSUKAMOTO, and Takao MAEDA. "603 Study on Motion Trajectory Generation Based on Updating Final-State Control." Proceedings of Conference of Tokai Branch 2016.65 (2016): _603–1_—_603–2_. http://dx.doi.org/10.1299/jsmetokai.2016.65._603-1_.

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Nguyen, Manh-Cuong, and Duc-Phuc Vuong. "The optimal control system of the ship based on the linear quadratic regular algorithm." International Journal of Electrical and Computer Engineering (IJECE) 10, no. 5 (October 1, 2020): 4562. http://dx.doi.org/10.11591/ijece.v10i5.pp4562-4568.

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In this paper, the authors propose an optimal controller for the ship motion. Firstly, the model and dynamic equations of the ship motion are presented. Based on the model of the ship motion, the authors build the linear quadratic regular algorithm-based control system of ship motion to minimize the error between the desired trajectory and the response trajectory. The task of the controller is to control the trajectory of the ship to coincide with the desired trajectory. The ship model and controller are built to investigate the system quality through Matlab-Simulink software. The results show that the quality of the hold control system is very high. The trajectory of a ship always follows the desired trajectory with very small errors.

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Li, Peng, and Jihe Zhou. "Motion Tracking and Detection System Based on Motion Sensor." Mobile Information Systems 2022 (April 22, 2022): 1–10. http://dx.doi.org/10.1155/2022/8681492.

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To solve the problem of large error of motion MEMS sensor in motion trajectory detection, a motion trajectory tracking and detection system based on motion sensor is proposed. The principle of trajectory tracking is that the three-dimensional velocity and displacement can be obtained by integrating the acceleration. In this paper, acceleration sensor is used to obtain acceleration data of moving object. In order to reduce the data measurement error, a Kalman filter is designed and implemented to eliminate random noise. Aiming at the system nonlinear error, a two speed sampling compensation algorithm is designed and implemented by using the random characteristics of kernel process scheduling algorithm. The system accuracy is significantly improved without increasing the computational burden. According to the characteristics of floating-point instruction system on Advanced RISC Machine (ARM) platform, the algorithms of process core modules such as square root and matrix multiplication are optimized and improved, which greatly improves the computing performance of the system. According to the results of the study, the average error of measurement of X-line displacement measurement of the space control system is 8.06%, the average error of measurement of Y-line displacement measurement is 7.41%, the average error of measurement of Z-line displacement measurement is 9.61%, and the average error of 3D dimensional measurement is 7.6%. The effectiveness and feasibility of the system are verified.

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Mei, Jiangping, Fan Zhang, Jiawei Zang, Yanqin Zhao, and Han Yan. "Trajectory optimization of the 6-degrees-of-freedom high-speed parallel robot based on B-spline curve." Science Progress 103, no. 1 (October 10, 2019): 003685041988011. http://dx.doi.org/10.1177/0036850419880115.

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According to the problem that the existing high-speed parallel robot cannot satisfy the operation requirements of non-planar industrial production line, a 6-degrees-of-freedom high-speed parallel robot is proposed to carry out the kinematic and dynamic analyses. Combining with the door-type trajectory commonly used by the parallel robot, it adopts 3-, 5-, and 7-time B-spline curve motion law to conduct the trajectory planning in operation space. Taking the average cumulative effect of joint jerky as the optimization target, a trajectory optimization method is proposed to improve the smoothness of robot end-effector motion with the selected motion law. Furthermore, to solve the deformation problem of the horizontal motion stage of the trajectory, a mapping model between the control point subset of B-spline and the motion point subset of trajectory is established. Based on the main diagonally dominant characteristic of the coefficient matrix, the trajectory deformation evaluation index is constructed to optimize the smoothness and minimum deformation of the robot motion trajectory. Finally, compared to without the optimization, the maximum robot joint jerk decreases by 69.4% and 72.3%, respectively, and the maximum torque decreases by 51.4% and 38.9%, respectively, under a suitable trajectory deformation.

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Zhang, Shuo, Jian Zhang, and Lin Qi. "Trajectory Data Compression Algorithm Based on Motion State Changing." Mathematical Problems in Engineering 2021 (February 28, 2021): 1–8. http://dx.doi.org/10.1155/2021/6647074.

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The trajectory information generated by the moving object plays an important role in studying the object movement. In this paper, a trajectory data compression algorithm based on the motion state changing is proposed to reduce trajectory data storage space and increase compression speed, which can accurately show the motion state and trajectory characteristics. This study has certain significance for the exploration of mass traffic data and the planning of traffic network. Combining the angle threshold with the velocity threshold of a moving object, the key data points are found and the redundant information is removed. Subsequently, the compressed trajectory is obtained. The experimental results show that the new algorithm can help to improve compression efficiency. The compressed trajectory has high similarity with the original trajectory in movement tendency.

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Kim, Junsoo, Kichun Jo, Wonteak Lim, and Myoungho Sunwoo. "A probabilistic optimization approach for motion planning of autonomous vehicles." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 232, no. 5 (August 16, 2017): 632–50. http://dx.doi.org/10.1177/0954407017704782.

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This paper presents a novel probabilistic approach for improving the motion planning performance of autonomous driving. The proposed approach is based on the sampling-based planning algorithm, which generates an optimal trajectory from a set of trajectory candidates. In order to treat the uncertainty in the perception data and the vehicle system, the particle filter framework is applied to the motion planning algorithm with four main steps: the time update of the trajectory candidates, the perception measurement update, the trajectory selection and the motion goal resampling. Since the proposed planning algorithm recursively generates an optimal trajectory, the time update of the trajectory candidate updates the motion goals of the trajectory candidates in the previous step using the vehicle model, and it also generates a new set of candidates. In order to evaluate the optimality of each candidate with regard to the safety and the reliability, a perception measurement update is performed. In this step, the importance weight of each candidate is computed using perception data and its adaptive likelihood function. Based on the candidates with updated importance weights, an optimal trajectory is determined in the trajectory selection. Then, the motion goal resampling modifies the set of motion goals based on the importance weights for efficient management of the motion goals in the iterative planning algorithm. The developed algorithm is validated using various types of test. The results show that the proposed method not only provides an integrated probabilistic interface between the perception and the planning but also results in an excellent performance in terms of the computation efficiency.

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Ge, Q. J., and Donglai Kang. "Motion Interpolation With G2 Composite Be´zier Motions." Journal of Mechanical Design 117, no. 4 (December 1, 1995): 520–25. http://dx.doi.org/10.1115/1.2826713.

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This paper deals with smooth motion interpolation. It presents two geometric algorithms for synthesizing composite Be´zier motions with second-order geometric continuity (G2). The first one is a direct algorithm for constructing a G2 spline motion that approximates a set of displacements; the second one is an inverse design algorithm for a G2 spline motion that interpolates through a set of displacements. The results are useful for computer aided motion animation, and Cartesian trajectory generation for CNC machines and robot manipulators.

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Thawani, Akanksha, and Mahesh S. Tirumkudulu. "Trajectory of a model bacterium." Journal of Fluid Mechanics 835 (November 27, 2017): 252–70. http://dx.doi.org/10.1017/jfm.2017.758.

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It is well known that bacteria, such as Escherichia coli, propel themselves in aqueous media by rotating helically shaped flagella. While a number of theoretical approaches have been proposed to model the detailed swimming motion, a rigorous comparison with experimental data is lacking due to the difficulty in simultaneously visualizing the motion of the head and the flagella along with the resulting trajectory. To this end, we have built a macroscopic working model of a bacterium and visualized its detailed motion in high-viscosity liquid. We show that a small asymmetry in the mass distribution in the head can lead to helical trajectories with large pitch and radius, which are reminiscent of the wiggling trajectories observed for swimming bacteria. The detailed motion agrees well with the predictions from slender-body theory that accounts for the asymmetric mass distribution in the head. Our study shows that the trajectory consists of two helical trajectories of different length scales – a large one caused by the asymmetric mass distribution and set by the head rotation rate, and a smaller one caused by the rotating flagellum and set by its rotation rate. We discuss implications of these results on the wiggling trajectories of swimming bacteria.

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Healy, Liam M., and C. Glen Henshaw. "Trajectory Guidance Using Periodic Relative Orbital Motion." Journal of Guidance, Control, and Dynamics 38, no. 9 (September 2015): 1714–24. http://dx.doi.org/10.2514/1.g000945.

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Michna, Viktor, Petr Wagner, and Zdenek Machacek. "Optimization of Robot Trajectory with Motion Constraints." IFAC Proceedings Volumes 43, no. 24 (2010): 144–49. http://dx.doi.org/10.3182/20101006-2-pl-4019.00028.

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Watanabe, Katsumi, and Shinsuke Shimojo. "Postcoincidence trajectory duration affects motion event perception." Perception & Psychophysics 63, no. 1 (January 2001): 16–28. http://dx.doi.org/10.3758/bf03200498.

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Wu, Shandong, and Y. F. Li. "Motion trajectory reproduction from generalized signature description." Pattern Recognition 43, no. 1 (January 2010): 204–21. http://dx.doi.org/10.1016/j.patcog.2009.05.019.

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Yang, Jianyu, Junsong Yuan, and Youfu Li. "Parsing 3D motion trajectory for gesture recognition." Journal of Visual Communication and Image Representation 38 (July 2016): 627–40. http://dx.doi.org/10.1016/j.jvcir.2016.04.010.

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Olearczyk, Jacek, Ahmed Bouferguène, Mohamed Al-Hussein, and Ulrich (Rick) Hermann. "Automating motion trajectory Of crane-lifted loads." Automation in Construction 45 (September 2014): 178–86. http://dx.doi.org/10.1016/j.autcon.2014.06.001.

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Miroshnik, I. V., and S. M. Korolev. "Trajectory Motion Control of Symmetrical Nonlinear Plants." IFAC Proceedings Volumes 28, no. 14 (June 1995): 607–12. http://dx.doi.org/10.1016/s1474-6670(17)46895-9.

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Lu, Wei, Xiang Wei, Weiwei Xing, and Weibin Liu. "Trajectory-based motion pattern analysis of crowds." Neurocomputing 247 (July 2017): 213–23. http://dx.doi.org/10.1016/j.neucom.2017.03.074.

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何, 红丽. "Study on Trajectory Algorithm of Motion Platform." Journal of Aerospace Science and Technology 03, no. 02 (2015): 13–18. http://dx.doi.org/10.12677/jast.2015.32002.

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Verghese, P., and J. Coughlan. "Evolution of a motion trajectory over time." Journal of Vision 7, no. 9 (March 18, 2010): 1013. http://dx.doi.org/10.1167/7.9.1013.

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Li, Wei, and Edward Red. "A joint trajectory generator for motion recovery." Robotica 21, no. 2 (February 19, 2003): 185–91. http://dx.doi.org/10.1017/s0263574702004897.

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This paper describes an adaptive S-curve used to recover a tool path upon a system crash in the Windows operating system (OS). For a mechanism such as a robot or machine tool, the joint values, being delivered as setpoints to the servo-controller, are dynamically recorded by the real-time operating system also residing on the computer. The real-time OS can control the abort and record pertinent motion data after Windows OS crash.Upon system recovery, the recovery trajectory generator examines the setpoints intervals to determine the current slow joint. At every trajectory step, and for the current slow joint, the S-curve velocity profile applies the joint entry state (position, speed, acceleration, and jerk) to interpolate the motion between the setpoints in a reverse direction. The other joints are proportionally interpolated (slowed) so that they pass through each setpoint simultaneously with the slow joint, but in a reverse direction.The trajectory algorithm is optimal since the slow joint always uses the maximum allowable jerk to change the profile speed and acceleration for each trajectory step.

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TANAKA, Yoshito, Junko ISHII, and Isao YOKOMICHI. "Control of Motion Trajectory on Parallel Mechanisms." Proceedings of the JSME annual meeting 2004.4 (2004): 65–66. http://dx.doi.org/10.1299/jsmemecjo.2004.4.0_65.

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Hidaka, S., M. Nagai, P. J. Bennett, A. B. Sekuler, and J. Gyoba. "Impaired luminance detection in apparent motion trajectory." Journal of Vision 9, no. 8 (March 24, 2010): 687. http://dx.doi.org/10.1167/9.8.687.

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Journal articles on the topic 'Trajectory of motion'

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