Forward Kinematic Analysis of Kinematically Redundant Hybrid Parallel Robots

2020 ◽  
Vol 12 (6) ◽  
Author(s):  
Kefei Wen ◽  
Clément M. Gosselin
Keyword(s):  
Real Time ◽  
Unique Solution ◽  
Kinematic Analysis ◽  
Parallel Robots ◽  
Degree Of Freedom ◽  
Real Time Control ◽  
The Real ◽  
Time Control ◽  
Forward Kinematic Problem ◽  
Forward Kinematic

Abstract This paper focuses on the forward kinematic analysis of (6 + 3)-degree-of-freedom kinematically redundant hybrid parallel robots. Because all of the singularities are avoidable, the robot can cover a very large orientational workspace. The control of the robot requires the solution of the direct kinematic problem using the actuator encoder data as inputs. Seven different approaches of solving the forward kinematic problem based on different numbers of extra encoders are developed. It is revealed that five of these methods can produce a unique solution analytically or numerically. An example is given to validate the feasibility of these approaches. One of the provided approaches is applied to the real-time control of a prototype of the robot. It is also revealed that the proposed approaches can be applied to other kinematically redundant hybrid parallel robots proposed by the authors.

Using graphs to construct a math model of a microcontroller-based system for preset rate control of a flywheel motor to be used in high-dynamics spacecraft

2020 ◽  
pp. 126-134
Author(s):  
Vladimir V. NEKRASOV
Keyword(s):  
Real Time ◽  
Rotation Rate ◽  
Control Function ◽  
Real Time Control ◽  
Math Model ◽  
The Real ◽  
Time Control ◽  
Power Matrix ◽  
High Dynamics ◽  
Stated Problem

Developing a microcontroller-based system for controlling the flywheel motor of high-dynamics spacecraft using Russian-made parts and components made it possible to make statement of the problem of searching control function for a preset rotation rate of the flywheel rotor. This paper discusses one of the possible options for mathematical study of the stated problem, namely, application of structural analysis based on graph theory. Within the framework of the stated problem a graph was constructed for generating the new required rate, while in order to consider the stochastic case option the incidence and adjacency matrices were constructed. The stated problem was solved using a power matrix which transforms a set of contiguous matrices of the graph of admissible solution edge sequences, the real-time control function was found. Based on the results of this work, operational trials were run for the developed control function of the flywheel motor rotor rotation rate, a math model was constructed for the real-time control function, and conclusions were drawn about the feasibility of implementing the results of this study. Key words: Control function, graph, incidence matrix, adjacency matrix, power matrix, microcontroller control of the flywheel motor, highly dynamic spacecraft.

Optimization of the real-time control strategy in petroleum-refining catalyst production wastewater treatment with shortcut nitrification

RSC Advances ◽  
2015 ◽  
Vol 5 (105) ◽  
pp. 86490-86496 ◽  
Author(s):  
Tianqi Ma ◽  
Shaohui Guo ◽  
Zhihui Guo ◽  
Qiushi Zhu ◽  
Jinfu Chen
Keyword(s):  
Wastewater Treatment ◽  
Real Time ◽  
Control Strategy ◽  
Control Parameter ◽  
Petroleum Refining ◽  
Real Time Control ◽  
High Ph ◽  
The Real ◽  
Time Control ◽  
Catalyst Production

Indicated high pH benefits the accuracy of real-time control strategy, explained why DO as a control parameter is unreliable.

Real-Time Pseudodielectric Function of Low-Temperature-Grown GaAs

2000 ◽  
Vol 618 ◽  
Author(s):  
D.A. Gajewski ◽  
J.E. Guyer ◽  
J.J. Kopanski ◽  
J.G. Pellegrino
Keyword(s):  
Low Temperature ◽  
Real Time ◽  
Diffuse Reflectance Spectroscopy ◽  
High Energy ◽  
Real Time Control ◽  
The Real ◽  
Time Control ◽  
Active Feedback ◽  
Low Temperature Grown Gaas ◽  
Lt Gaas

ABSTRACTWe present the real-time pseudodielectric function <ε(E)> of low-temperature-grown GaAs (LT-GaAs) thin films during the growth as a function of growth temperature Tg and thickness. We obtained accurate measurements of the real-time <εc(E)> by using in situspectroscopic ellipsometry (SE) in conjunction with active feedback control of the substrate temperature using diffuse reflectance spectroscopy. We show that for epitaxial LT-GaAs layers, the peak in the imaginary pseudodielectric function <ε2(E)> decreases in amplitude and sharpness systematically with decreasing Tg. We also revealed an abrupt change in <εc(E)> near the critical epitaxial thickness hepi, the value of which decreases with decreasing Tg. Above hepi, the LT-GaAs grows polycrystalline (amorphous) above (below) Tg ∼ 190°C. We also simultaneously monitored the surface roughness and crystallinity by using real-time reflection high-energy electron diffraction (RHEED). These results represent progress in obtaining real-time control over the composition and morphology of LT-GaAs

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