scholarly journals An Underwater Vector Propulsion Device Based on the RS+2PRS Parallel Mechanism and Its Attitude Control Algorithm

2019 ◽  
Vol 9 (23) ◽  
pp. 5210 ◽  
Author(s):  
Wang ◽  
Guo ◽  
Zhong
Keyword(s):  
Attitude Control ◽  
Parallel Mechanism ◽  
Control Algorithm ◽  
Simulation Analysis ◽  
Autonomous Underwater Vehicles ◽  
Propulsion System ◽  
Precession Angle ◽  
Nutation Angle ◽  
Prismatic Joints ◽  
Spherical Parallel Mechanism

In order to overcome the disadvantages of some existing autonomous underwater vehicles (AUVs), such as actuator extraposition and degree-of-freedom (DOF) redundancy, a 2-DOF vector propeller propulsion system with built-in actuator based on the deficient DOF parallel mechanism is proposed. The RS+2PRS (Revolute-Spherical+ Prismatic-Revolute-Spherical) parallel mechanism is used as the main structure, and the driving parts are placed in the interior of the AUV cabin, which is beneficial to the sealing and protection of the propulsion system. In addition, the motion parameters decoupling shows that the two independent parameters are the precession angle and the nutation angle of the propeller installation platform. Therefore, the attitude control algorithm uses two prismatic joints as driving units to establish the nonlinear mapping model with the two Euler attitude angles. In the end, the simulation analysis and the real device are used to verify the feasibility of the attitude control algorithm and the in situ adjustment function of the propeller, which lays the theoretical foundation for engineering applications in the future.

Kinematic and Modal Simulation Analysis of the Bionic Eye Based on Spherical Parallel Mechanism (SPM)

2011 ◽  
Vol 128-129 ◽  
pp. 1151-1156 ◽  
Author(s):  
Jun Luo ◽  
Qi Ming Guo ◽  
Heng Yu Li ◽  
Chao Jiong Huang ◽  
Shao Rong Xie
Keyword(s):  
Modal Analysis ◽  
Motion Control ◽  
Parallel Mechanism ◽  
Optimization Design ◽  
Simulation Analysis ◽  
Displacement Velocity ◽  
Kinematics Analysis ◽  
End Effector ◽  
Bionic Eye ◽  
Spherical Parallel Mechanism

In order to realize stable tracking under bumpy environment, the robot bionic eye constructed by spherical parallel mechanism with 3 DOF is designed based on the characteristics of human being’s eyes. ANSYS and ADAMS are utilized to conduct modal and kinematics property analysis respectively. According to the result of ANSYS modal analysis, the structure highly meets the demands of function and reliability, which lays the foundation for optimization and bump-resistance design. Through ADAMS kinematics analysis, displacement, velocity and acceleration curves of mechanism end effector were obtained, which provides reference for motion control and optimization design.

scholarly journals Design of Satellite Attitude Control Algorithm Based on the SDRE Method Using Gas Jets and Reaction Wheels

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Luiz C. G. de Souza ◽  
Victor M. R. Arena
Keyword(s):  
Attitude Control ◽  
Control Algorithm ◽  
Controller Design ◽  
Algorithm Design ◽  
Large Angle ◽  
Space Mission ◽  
Control Technique ◽  
Gas Jets ◽  
State Dependent ◽  
Highly Nonlinear

An experimental attitude control algorithm design using prototypes can minimize space mission costs by reducing the number of errors transmitted to the next phase of the project. The Space Mechanics and Control Division (DMC) of INPE is constructing a 3D simulator to supply the conditions for implementing and testing satellite control hardware and software. Satellite large angle maneuver makes the plant highly nonlinear and if the parameters of the system are not well determined, the plant can also present some level of uncertainty. As a result, controller designed by a linear control technique can have its performance and robustness degraded. In this paper the standard LQR linear controller and the SDRE controller associated with an SDRE filter are applied to design a controller for a nonlinear plant. The plant is similar to the DMC 3D satellite simulator where the unstructured uncertainties of the system are represented by process and measurements noise. In the sequel the State-Dependent Riccati Equation (SDRE) method is used to design and test an attitude control algorithm based on gas jets and reaction wheel torques to perform large angle maneuver in three axes. The SDRE controller design takes into account the effects of the plant nonlinearities and system noise which represents uncertainty. The SDRE controller performance and robustness are tested during the transition phase from angular velocity reductions to normal mode of operation with stringent pointing accuracy using a switching control algorithm based on minimum system energy. This work serves to validate the numerical simulator model and to verify the functionality of the control algorithm designed by the SDRE method.

Research on Fuzzy Control of Mine Ventilation Based on Embedded Systems

2014 ◽  
Vol 686 ◽  
pp. 126-131
Author(s):  
Xiao Yan Sha
Keyword(s):  
Fuzzy Control ◽  
Control Algorithm ◽  
Fuzzy Controller ◽  
Simulation Analysis ◽  
Control Unit ◽  
Real Time Control ◽  
Embedded Processor ◽  
Feed Forward ◽  
Time Control ◽  
Software And Hardware

Taking embedded processor as the core control unit, the paper designs the fan monitoring system software and hardware to achieve the fan working condition detection and real-time control. For the control algorithm, the paper analyzes the fuzzy control system theory and composition, and then combined with tunnel ventilation particularity, introduce feed-forward model to predict the incremental acquisition of pollutants to reduce lag, combined with the system feedback value and the set value, by calculate of two independent computing fuzzy controller, and ultimately determine the number of units increase or decrease in the tunnel jet fans start and stop. Through simulation analysis, the introduction of a feed-forward signal, it can more effectively improve the capability of the system impact of interference.

Statics Analysis of the Mechanical Model of Nucleosome

2011 ◽  
Vol 343-344 ◽  
pp. 661-667 ◽  
Author(s):  
Yun Xue ◽  
De Wei Weng ◽  
Gang Ming Gong
Keyword(s):  
Mechanical Model ◽  
The Other ◽  
Elastic Rod ◽  
Equilibrium Equations ◽  
Constraint Force ◽  
Precession Angle ◽  
Nutation Angle ◽  
Analytic Expression ◽  
Set Up ◽  
Calculated Analysis

Mechanical model of nucleoside and its equilibrium equations are set up, and the mechanical properties on the equilibrium position are analyzed. In the case constraint force and electrostatic attraction between cylinder OH and elastic rod are balanced, the analytic expression of nutation angle of the section and its conditions of existence are given. It is show that the cylinder OH can maintain equilibrium at any range of the precession angle. In the other case when unbanced, there is phenomenon of separation of elastic rod from cylinder OH in the spiral wound 2 circles, and numerical solution of the precession angle at separation points are calculated. Analysis of equilibrium of cylinder H1 illustrates that the generatrix of cylinder H1 and OH are not parallel, and the angle between them is obtained

Inverse dynamics and servomotor parameter estimation of a 2-DOF spherical parallel mechanism

2008 ◽  
Vol 51 (3) ◽  
pp. 288-301 ◽  
Author(s):  
HaiTao Liu ◽  
JiangPing Mei ◽  
XueMan Zhao ◽  
Tian Huang ◽  
D. G. Chetwynd
Keyword(s):  
Parameter Estimation ◽  
Parallel Mechanism ◽  
Inverse Dynamics ◽  
Spherical Parallel Mechanism
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