scholarly journals Construction of symplectic full-turn maps by application of an arbitrary tracking code

2003 ◽  
Author(s):  
R.L. Warnock
Keyword(s):  
Author(s):  
Konstantin Litsin ◽  
◽  
Sergei Baskov ◽  
Yaroslav Makarov ◽  
◽  
...  

Currently, the penetration of industrial robots into all sectors of the economy is increasing. However, there is an acute problem of conducting preliminary tests. The use of the digital twin as a replacement for the industrial robot is driven by high economic costs. In order to reduce the cost of the project, a solution is proposed to conduct preliminary tests on the developed model. The article developed a mathematical model of one of the drives of the industrial robot manipulator Yaskawa Motoman MH50-35. The model is suitable for researching the movement of the robot' tool. A mathematical description of a permanent magnet synchronous motor SGMJV-09A in a rotating coordinate system is given and a block diagram of the power part of the drive is made. A system for regulating the position of the robot's tool with a nonlinear position controller has been synthesized. Based on the results of modeling the operation of an electric drive in the Matlab Simulink environment, the degree of correspondence of the developed model to a real object was assessed and conclusions were drawn about the limits of its applicability for studying the operation of an electric drive of a robotic arm. The accuracy of working out the task for turning the wrist is 0.0001 rad, there is no overshoot in position, and the time for completing a full turn of the tool is 1.07 s.


Author(s):  
K. D. Chaney ◽  
J. K. Davidson

Abstract A new method is developed for determining both a satisfactory location of a workpiece and a suitable mounting-angle of the tool for planar RPR robots that can provide dexterous workspace. The method is an analytical representation of the geometry of the robot and the task, and is particularly well suited to applications in which the task requires large rotations of the end-effector. It is determined that, when the task requires that the end-effector rotate a full turn at just two locations and when the first or third joint in the robot is rotatable by one turn, then the radial location of the workpiece is fixed in the workcell but its angular location is not fixed. When the mounting-angle of the tool is also a variable, the method accommodates tasks in which the tool must rotate a full turn at three locations on the workpiece. The results are presented as coordinates of points in a two-dimensional Cartesian reference frame attached to the workcell. Consequently, a technician or an engineer can determine the location for the workpiece by laying out these coordinates directly in the workcell. Example problems illustrate the method. Practical applications include welding and deposition of adhesives.


2012 ◽  
Vol 33 (1) ◽  
pp. 33-43 ◽  
Author(s):  
Thomas Heinen ◽  
Damian Jeraj ◽  
Pia Vinken ◽  
Konstantinos Velentzas

Rotational Preference in GymnasticsIn gymnastics, most skills incorporate rotations about one or more body axes. At present, the question remains open if factors such as lateral preference and/or vestibulo-spinal asymmetry are related to gymnast's rotational preference. Therefore, we sought to explore relationships in gymnast's rotation direction between different gymnastic skills. Furthermore, we sought to explore relationships between rotational preference, lateral preference, and vestibulo-spinal asymmetry. In the experiment n = 30 non-experts, n = 30 near-experts and n = 30 experts completed a rotational preference questionnaire, a lateral preference inventory, and the Unterberger-Fukuda Stepping Test. The results revealed, that near-experts and experts more often rotate rightward in the straight jump with a full turn when rotating leftward in the round-off and vice versa. The same relationship was found for experts when relating the rotation preference in the handstand with a full turn to the rotation preference in the straight jump with a full turn. Lateral preference was positively related to rotational preference in non-expert gymnasts, and vestibulo-spinal asymmetry was positively related to rotational preference in experts. We suggest, that gymnasts should explore their individual rotational preference by systematically practicing different skills with a different rotation direction, bearing in mind that a clearly developed structure in rotational preference between different skills may be appropriate to develop more complex skills in gymnastics.


2018 ◽  
Vol 10 (3) ◽  
Author(s):  
Xianwen Kong ◽  
Xiuyun He ◽  
Duanling Li

This paper deals with a 6R single-loop overconstrained spatial mechanism that has two pairs of revolute joints with intersecting axes and one pair of revolute joints with parallel axes. The 6R mechanism is first constructed from an isosceles triangle and a pair of identical circles. The kinematic analysis of the 6R mechanism is then dealt with using a dual quaternion approach. The analysis shows that the 6R mechanism usually has two solutions to the kinematic analysis for a given input and may have two circuits (closure modes or branches) with one or two pairs of full-turn revolute joints. In two configurations in each circuit of the 6R mechanism, the axes of four revolute joints are coplanar, and the axes of the other two revolute joints are perpendicular to the plane defined by the above four revolute joints. Considering that from one configuration of the 6R mechanism, one can obtain another configuration of the mechanism by simply renumbering the joints, the concept of two-faced mechanism is introduced. The formulas for the analysis of plane symmetric spatial triangle are also presented in this paper. These formulas will be useful for the design and analysis of multiloop overconstrained mechanisms involving plane symmetric spatial RRR triads.


Hoehnea ◽  
2018 ◽  
Vol 45 (1) ◽  
pp. 143-148
Author(s):  
Sandra Maria Alves-da-Silva ◽  
Carlos Eduardo de Mattos Bicudo

ABSTRACT As a result of the taxonomic survey of the pigmented Euglenophyceae of Lago da Ponte, an artificial pond located at the Porto Alegre Botanical Garden, State of Rio Grande do Sul, Southern Brazil and samples gathered later on from this same water body, a new species of Phacus (Euglenophyceae, Phacaceae), P. multifacies Alves-da-Silva & C. Bicudo, sp. nov., is here described and proposed as new to science. Cell displacement turning ventrally one full turn round itself and also rotating around its longitudinal axis and the presence of a dorsal wing-like expansion next to the caudal process are the main diagnostic features of the new species. Physical and chemical information on the pond water is presented.


Sensor Review ◽  
2014 ◽  
Vol 34 (4) ◽  
pp. 382-388 ◽  
Author(s):  
Damir Krklješ ◽  
Dragana Vasiljević ◽  
Goran Stojanović

Purpose – This paper aims to present a prototype of a capacitive angular-position sensor which exploits advantages of flexible/printed electronics. The novelty of the sensor is that the capacitor structure is placed at the circumference of the rotor and stator, that it posses two channels (capacitor structures) electrically shifted for p/4 and that the rotor is common for both channels. The electrodes of the sensing capacitor are digitated, providing a triangular transfer function. Design/methodology/approach – This sensor prototype consists of two flexible inkjet-printed silver electrodes forming a cylindrical capacitor structure. One of them is wrapped around the stator and another is wrapped around the rotor part of a simple mechanical platform used to precisely adjust the angular displacement. Findings – The capacitance as a function of angular position was measured using an inductance capacitance impedance (LCZ) Meter, and results are presented for a full-turn measurement range. The experimental results are compared with analytical ones and very good agreement has been achieved. Originality/value – The proposed capacitive sensor structure can be used as an absolute or an incremental encoder with different resolutions, and it can be applied in automotive industry or robotics.


1987 ◽  
Vol 61 (3) ◽  
pp. 979-981
Author(s):  
Satoshi Shimai ◽  
Hiroyuki Iso

24 CFW mice were trained in a newly developed wheel-running apparatus for avoidance learning in mice. Scrambled shock could be delivered through a ball bearing which supports the shaft of the wheel. Responses were defined as rotation of the wheel quarter, half, and full turn for three groups. Animals quickly developed the running response under a nondiscriminated avoidance schedule in all groups. These findings are consistent with previous data for rats.


Sign in / Sign up

Export Citation Format

Share Document