Analysis of the discontinuities in prioritized tasks-space control under discreet task scheduling operations

Keith,; Wieber,; Kheddar, Abderrahmane

doi:10.1109/iros.2011.6048309

Cited by 17 publications

(30 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, space-time data are not able to provide direct information on which tasks individual players were exploring and in what context, within the game. Because we were interested in the technical-tactical and exploratory behavior in the discrete task-space [52] the nominal scale was the scale of choice. Each 1 s window was defined as a 51-component binary vector representing the full action configuration during the same time interval.…”

Section: Methodsmentioning

confidence: 99%

Emergence of Exploratory, Technical and Tactical Behavior in Small-Sided Soccer Games when Manipulating the Number of Teammates and Opponents

et al. 2016

View full text Add to dashboard Cite

The effects that different constraints have on the exploratory behavior, measured by the variety and quantity of different responses within a game situation, is of the utmost importance for successful performance in team sports. The aim of this study was to determine how the number of teammates and opponents affects the exploratory behavior of both professional and amateur players in small-sided soccer games. Twenty-two professional (age 25.6 ± 4.9 years) and 22 amateur (age 23.1 ± 0.7 years) male soccer players played three small-sided game formats (4 vs. 3, 4 vs. 5, and 4 vs. 7). These trials were video-recorded and a systematic observation instrument was used to notate the actions, which were subsequently analyzed by means of a principal component analysis and the dynamic overlap order parameter (measure to identify the rate and breadth of exploratory behavior on different time scales). Results revealed that a higher the number of opponents required for more frequent ball controls. Moreover, with a higher number of teammates, there were more defensive actions focused on protecting the goal, with more players balancing. In relation to attack, an increase in the number of opponents produced a decrease in passing, driving and controlling actions, while an increase in the number of teammates led to more time being spent in attacking situations. A numerical advantage led to less exploratory behavior, an effect that was especially clear when playing within a team of seven players against four opponents. All teams showed strong effects of the number of teammates on the exploratory behavior when comparing 5 vs 7 or 3 vs 7 teammates. These results seem to be independent of the players’ level.

show abstract

Section: Methodsmentioning

confidence: 99%

Emergence of Exploratory, Technical and Tactical Behavior in Small-Sided Soccer Games when Manipulating the Number of Teammates and Opponents

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Much of earlier research has tried to assign priority between tasks [1][2] [3][4] to overcome incompatibility, also known as algorithmic singularity, between tasks. In spite of their successive achievements, there are some cases that fixed priority structures cannot fulfill task requirements, i.e., obstacle avoidance [5] [6], joint limits [7] [8], and task scheduling [9] [10], in which tasks need to be added, removed, or switched during operations.…”

Section: Introductionmentioning

confidence: 99%

“…Second, the parameters are coupled with task variables in an elaborate way, such that it is hard to analyze the behavior of the inverse mapping during transitions and it becomes aggravated near singularity. Third, it seems difficult to switch priority between tasks by interpolating task trajectories; it has been implemented by interpolating joint trajectories [8] [9].…”

Section: Introductionmentioning

confidence: 99%

Prioritized Inverse Kinematics with Multiple Task Definitions

Lee

2015

2015 IEEE International Conference on Robotics and Automation (ICRA)

View full text Add to dashboard Cite

We are proposing a general framework that incorporates multiple task definitions in the prioritized inverse kinematics problem. First, a mathematical description of multiple task definitions is constructed that provides an efficient way to show unprioritized or prioritized accumulations of tasks. Then, smooth transitions between all task definitions are studied, so a method, called task transition control, is developed that interpolates joint trajectories using barycentric coordinates and linear dynamical systems to overcome difficulties of interpolating task trajectories in the conventional methods. Consequently, smooth, arbitrary, and consecutive task transitions are achieved in a simple, direct, and general manner and also boundedness of joint trajectories is assured regardless of singularity. Lastly, the idea is tested by two kinematic simulations: obstacle avoidance with the KUKA LWR and task scheduling of a humanoid robot.

show abstract

“…{gerardo.jarquin,garechav,vicente.parra} @cinvestav.edu.mx in [11], by formulating variants of optimization problems. The authors proposed a linear interpolation strategy between control laws to swap two consecutive tasks.…”

mentioning

confidence: 99%

“…In this work, we focus on coupling TAs with recent continuous kinematic controllers reported in [9], [10] and [11]. This is possible because of the continuity properties of the proposed time base generator (TBG) that behaves as a TA.…”

mentioning

confidence: 99%

Continuous kinematic control with terminal attractors for handling task transitions of redundant robots

Jarquin¹,

Arechavaleta²,

Parra-Vega³

2013

2013 IEEE International Conference on Robotics and Automation

View full text Add to dashboard Cite

This paper proposes a general scheme based on terminal attractors to parametrize operational tasks with respect to time in continuous kinematic controllers. Commonly, a pseudo-inverse operator is applied to solve operational tasks. However, it is known that discontinuities in the control signals appear as a by-product of task transitions during motion execution. In particular, these transitions involve the insertion, removal and swapping of tasks. Recently, some methods have been reported that overcome such discontinuities in the control signals. In this work, we provide time parametrization capabilities to these continuous kinematic controllers in order to handle the time axis of operational tasks at will. Then, we show that the proposed scheme can be naturally extended for the case of prioritized kinematic tasks while preserving continuity under task transitions. Our scheme is validated in a real experiment with a NAO humanoid robot.

show abstract

Analysis of the discontinuities in prioritized tasks-space control under discreet task scheduling operations

Cited by 17 publications

References 14 publications

Emergence of Exploratory, Technical and Tactical Behavior in Small-Sided Soccer Games when Manipulating the Number of Teammates and Opponents

Emergence of Exploratory, Technical and Tactical Behavior in Small-Sided Soccer Games when Manipulating the Number of Teammates and Opponents

Prioritized Inverse Kinematics with Multiple Task Definitions

Continuous kinematic control with terminal attractors for handling task transitions of redundant robots

Contact Info

Product

Resources

About