Research on Control Algorithm for Mobile Welding Robot Using Kinematics Oscillator

2013 ◽  
Vol 303-306 ◽  
pp. 1678-1684
Author(s):  
Xian Chun Meng ◽  
Kai Li ◽  
Dong Mei Zhang ◽  
Jian Hu Zuo ◽  
Yan Jun Li
Keyword(s):  
Lyapunov Stability ◽  
Stability Criterion ◽  
Control Algorithm ◽  
Controller Design ◽  
Dynamic Parameters ◽  
Welding Robot ◽  
Holonomic Constraint ◽  
Lyapunov Stability Criterion ◽  
Mobile Welding Robot ◽  
Instantaneous Center

The dynamics equation of mobile welding robot is established. In controller design of the mobile welding robot, the non-holonomic constraint is introduced that limits the size of the transverse sliding and avoid the coordinates of the instantaneous center of rotation is larger than the wheelbase, to ensure the robot’s stability. Based on kinematics oscillator, the effect of uncertain dynamic parameters is considered. According to the Lyapunov stability criterion, the control algorithm is deduced. Simulating results by MATLAB software shows that the design of the control algorithm is stable, convergent and effective.

Hot Forming Optimization of ZK30 Magnesium Alloy

2018 ◽  
Vol 941 ◽  
pp. 2325-2330 ◽  
Author(s):  
Manuel Carsí ◽  
Fernando Carreño ◽  
Oscar A. Ruano
Keyword(s):  
Magnesium Alloy ◽  
Lyapunov Stability ◽  
Stability Criterion ◽  
Strain Rates ◽  
Optimum Temperature ◽  
Compression Tests ◽  
Deformation Bands ◽  
Lyapunov Stability Criterion ◽  
Reduced Costs ◽  
Using Data

The modeling of the forming of materials at high homologous temperatures allows obtaining optimum forming parameters, reduced costs and improving final properties of the finished product. In this work, the behavior of the ZK30 Magnesium alloy was characterized by means of compression tests at temperatures 300 to 450oC and strain rates between 0.1 and 8.7 s-1. Using data from these tests, the parameters of the Garofalo equation are calculated. In addition, by means of the second Lyapunov stability criterion, the optimum temperature at a given temperature is determined which should minimize the appearance of deformation bands and cracks during hot working. This temperature was found to be 641 K (368oC) at 8.7 s-1.

Bio-Inspired Nonholonomic Tracking Control

2013 ◽  
Author(s):  
Adam Shoemaker ◽  
Alexander Leonessa
Keyword(s):  
Obstacle Avoidance ◽  
Lyapunov Stability ◽  
Stability Criterion ◽  
Tracking Control ◽  
High Speed ◽  
Speed Tracking ◽  
Tracking Controller ◽  
Lyapunov Stability Criterion ◽  
Saturation Constraints ◽  
Nonholonomic Vehicles

The behavior of nature’s predators is considered for designing a high speed tracking controller for nonholonomic vehicles, whose dynamics are represented using a unicycle model. To ensure that the vehicle behavior closely resembles that of a predator, saturation constraints are added and accounted for using Lyapunov stability criterion. Following verification and comparison of the saturation constraints, the proposed algorithm is implemented on a testing platform. Based on the results presented, we believe the algorithm shows significant promise in high speed control and obstacle avoidance.

Stochasticity of Galactic Orbits of Star Clusters

2015 ◽  
Vol 24 (2) ◽  
Author(s):  
L. V. Smirnova
Keyword(s):  
Lyapunov Exponents ◽  
Lyapunov Stability ◽  
Stability Criterion ◽  
Star Clusters ◽  
Open Clusters ◽  
Stability Criteria ◽  
Poincaré Sections ◽  
Lyapunov Stability Criterion ◽  
Poincare Sections

AbstractThe Lyapunov, Lagrange and Poincaré criteria are tested for orbits of 461 open clusters in an axisymmetric potential. Lyapunov exponents and Poincaré sections are computed, and all of the trajectories are found to be stable according to the Lagrange and Poincaré stability criteria. At the same time, some trajectories appear to exhibit minor instability according to the Lyapunov stability criterion.

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