scholarly journals CAD Enabled Trajectory optimization and Accurate Motion Control for Repetitive Tasks.

Author(s):  
Nick Van Oosterwyck ◽  
Foeke Vanbecelaere ◽  
Michiel Haemers ◽  
David Ceulemans ◽  
Kurt Stockman ◽  
...  
2021 ◽  
Author(s):  
Yu Yang ◽  
Hongze Xu ◽  
Shaohua Li ◽  
Lingling Zhang ◽  
Xiuming Yao

Abstract Effective motion control can achieve accurate and fast positioning and movement of industrial robotics and improve industrial productivity significantly. Time-optimal trajectory optimization (TO) is a great concern in the motion control of robotics and can improve motion efficiency by providing high-speed and reasonable motion references to the motion controller. In this study, a new time-optimal TO strategy, polynomial interpolation function (PIF) combined with improved particle swarm optimization (PSO) considering kinematic and dynamic limits, successfully optimizes the movement time of the PUMA 560 serial manipulator along a randomly assigned path. The 4-3-4 PIF is first used to generate the smooth and 3-order continuous movement trajectories of six joints in joint space. The PSO with cosine decreasing weight (CDW-PSO) algorithm further reduces the trajectories movement time considering the limits of the angular displacement, angular velocity, angular acceleration, angular jerk, and joint torque. Experimental results show that the CDW-PSO algorithm achieves a better convergence rate of 23 and a better fitness value of 2.46 compared with the PSO with constant weight and linearly decreasing weight algorithms. The CDW-PSO optimized movement time is reduced by 83.6% compared to the manually setting movement time value of 15. The proposed time-optimal TO strategy can be conducted easily and directly search for global optimal solutions without approximation of the limits. The optimized trajectories could be incorporated in the motion controller of the actual manipulators due to considering the kinematic and dynamic limits.


2018 ◽  
Vol 27 (1) ◽  
pp. 5-21
Author(s):  
Amanda Dennis

Lying in ditches, tromping through mud, wedged in urns, trash bins, buried in earth, bodies in Beckett appear anything but capable of acting meaningfully on their environments. Bodies in Beckett seem, rather, synonymous with abjection, brokenness, and passivity—as if the human were overcome by its materiality: odours, pain, foot sores, decreased mobility. To the extent that Beckett's personae act, they act vaguely (wandering) or engage in quasi-obsessive, repetitive tasks: maniacal rocking, rotating sucking stones and biscuits, uttering words evacuated of sense, ceaseless pacing. Perhaps the most vivid dramatization of bodies compelled to meaningless, repetitive movement is Quad (1981), Beckett's ‘ballet’ for television, in which four bodies in hooded robes repeat their series ad infinitum. By 1981, has all possibility for intentional action in Beckett been foreclosed? Are we doomed, as Hamm puts it, to an eternal repetition of the same? (‘Moments for nothing, now as always, time was never and time is over, reckoning closed and story ended.’)This article proposes an alternative reading of bodily abjection, passivity and compulsivity in Beckett, a reading that implies a version of agency more capacious than voluntarism. Focusing on Quad as an illustrative case, I show how, if we shift our focus from the body's diminished possibilities for movement to the imbrication of Beckett's personae in environments (a mound of earth), things, and objects, a different story emerges: rather than dramatizing the impossibility of action, Beckett's work may sketch plans for a more ecological, post-human version of agency, a more collaborative mode of ‘acting’ that eases the divide between the human, the world of inanimate objects, and the earth.Movements such as new materialism and object-oriented ontology challenge hierarchies among subjects, objects and environments, questioning the rigid distinction between animate and inanimate, and the notion of the Anthropocene emphasizes the influence of human activity on social and geological space. A major theoretical challenge that arises from such discourses (including 20th-century challenges to the idea of an autonomous, willing, subject) is to arrive at an account of agency robust enough to survive if not the ‘death of the subject’ then its imbrication in the material and social environment it acts upon. Beckett's treatment of the human body suggests a version of agency that draws strength from a body's interaction with its environment, such that meaning is formed in the nexus between body and world. Using the example of Quad, I show how representations of the body in Beckett disturb the opposition between compulsivity (when a body is driven to move or speak in the absence of intention) and creative invention. In Quad, serial repetition works to create an interface between body and world that is receptive to meanings outside the control of a human will. Paradoxically, compulsive repetition in Beckett, despite its uncomfortable closeness to addiction, harnesses a loss of individual control that proposes a more versatile and ecologically mindful understanding of human action.


2019 ◽  
Vol 139 (5) ◽  
pp. 662-669
Author(s):  
Yuki Asai ◽  
Ryuichi Enomoto ◽  
Yuta Ueda ◽  
Daisuke Iwai ◽  
Kosuke Sato

2015 ◽  
Vol 135 (3) ◽  
pp. 246-257 ◽  
Author(s):  
Mototsugu Omura ◽  
Tomoyuki Shimono ◽  
Yasutaka Fujimoto
Keyword(s):  

Author(s):  
Fumikazu MINAMIYAMA ◽  
Hidetsugu KOGA ◽  
Kentaro KOBAYASHI ◽  
Masaaki KATAYAMA

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