Time Optimal Seek Trajectories for a Dual Stage Optical Disk Drive Actuator

1991 ◽  
Vol 113 (3) ◽  
pp. 534-536 ◽  
Author(s):  
J. McCormick ◽  
R. Horowitz
Keyword(s):  
High Performance ◽  
Necessary Conditions ◽  
Closed Form Solution ◽  
Disk Drive ◽  
Form Solution ◽  
Actuator Disk ◽  
Optical Disk Drive ◽  
Time Optimal ◽  
Dual Stage ◽  
Optical Disks

A closed-form solution for the time optimal control of a dual actuator disk drive system that takes into account the physical constraint limiting the relative motion of the fine and coarse actuator has been derived. The result is useful for determining track seeking strategies for high performance optical disks. The application of the necessary conditions to a simplified model of the compound actuator is presented and a solution derived.

New continuum surgical robot based on hybrid concentric tube-tendon driven mechanism

2021 ◽  
pp. 095440622110424
Author(s):  
Mohammed Abdel-Nasser ◽  
Omar Salah
Keyword(s):  
Inverse Kinematics ◽  
High Performance ◽  
Analytical Study ◽  
Fuzzy Inference ◽  
Closed Form Solution ◽  
Form Solution ◽  
Robot Arm ◽  
Inference System ◽  
Neuro Fuzzy ◽  
Intelligent Approach

Robotics technology is used widely in minimally invasive surgery (MIS) which provides high performance and accuracy. The most famous robot arm mechanisms, which are used in MIS, are tendon-driven mechanism (TDM), and concentric tube mechanism (CTM). Unfortunately, these mechanisms until now have some limitations, i.e. making friction with the tissue during extracting and retracting and strain limits, for TDM and CTM respectively. A new hybrid concentric tube-tendon driven mechanism (HCTDM) is proposed to overcome these limitations. HCTDM enables the end-effector to get close to and get away from the surgical area during the operation without harming the tissue and with more flexibility. In addition to that, the workspace increases as a result of this combination, too. This benefit serves MIS, especially endoscopic surgeries (ESs). We did an analytical study of this idea and got the forward kinematics. In the inverse kinematics, an intelligent approach which is called an adaptive neuro-fuzzy inference system (ANFIS) is used because the closed-form solution is more complicated for such these mechanisms. Finally, HCTDM is analyzed and evaluated by using a computer simulation. The simulation results show that the workspace becomes wider and has more dexterity than use TDM or CTM individually. Furthermore, various trajectories are used to test the mechanism and the kinematic analysis, which show the mechanism can follow and track the trajectories with maximum mean error 1.279, 0.7027, and [Formula: see text] for X, Y, and Z axes respectively.

scholarly journals Closed-form solution of discrete-time optimal control and its convergence

2018 ◽  
Vol 12 (3) ◽  
pp. 413-418 ◽  
Author(s):  
Hehong Zhang ◽  
Yunde Xie ◽  
Gaoxi Xiao ◽  
Chao Zhai
Keyword(s):  
Optimal Control ◽  
Closed Form ◽  
Discrete Time ◽  
Closed Form Solution ◽  
Form Solution ◽  
Time Optimal Control ◽  
Time Optimal

Time optimal seek control for a coupled dual stage disk drive actuator

1997 ◽  
Vol 33 (5) ◽  
pp. 2629-2631 ◽  
Author(s):  
Jian-Dong Yang ◽  
Long-Fa Pan ◽  
Xian-Deng Pei ◽  
Chang-Sheng Xie ◽  
Xiang-Ying Cao ◽  
...  
Keyword(s):  
Disk Drive ◽  
Time Optimal ◽  
Dual Stage

scholarly journals PSO-Based Soft Lunar Landing with Hazard Avoidance: Analysis and Experimentation

Aerospace ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 195
Author(s):  
Andrea D’Ambrosio ◽  
Andrea Carbone ◽  
Dario Spiller ◽  
Fabio Curti
Keyword(s):  
Real Time ◽  
Inverse Dynamics ◽  
A Priori ◽  
Closed Form Solution ◽  
Control Policy ◽  
Form Solution ◽  
Soft Landing ◽  
Lunar Landing ◽  
Optimal Guidance ◽  
Time Optimal

The problem of real-time optimal guidance is extremely important for successful autonomous missions. In this paper, the last phases of autonomous lunar landing trajectories are addressed. The proposed guidance is based on the Particle Swarm Optimization, and the differential flatness approach, which is a subclass of the inverse dynamics technique. The trajectory is approximated by polynomials and the control policy is obtained in an analytical closed form solution, where boundary and dynamical constraints are a priori satisfied. Although this procedure leads to sub-optimal solutions, it results in beng fast and thus potentially suitable to be used for real-time purposes. Moreover, the presence of craters on the lunar terrain is considered; therefore, hazard detection and avoidance are also carried out. The proposed guidance is tested by Monte Carlo simulations to evaluate its performances and a robust procedure, made up of safe additional maneuvers, is introduced to counteract optimization failures and achieve soft landing. Finally, the whole procedure is tested through an experimental facility, consisting of a robotic manipulator, equipped with a camera, and a simulated lunar terrain. The results show the efficiency and reliability of the proposed guidance and its possible use for real-time sub-optimal trajectory generation within laboratory applications.

High-performance three-beam magneto-optical disk drive

1992 ◽  
Author(s):  
Shigenori Yanagi ◽  
Shigeru Arai ◽  
Masateru Sasaki
Keyword(s):  
High Performance ◽  
Disk Drive ◽  
Optical Disk ◽  
Optical Disk Drive
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