Optimal control and sensitivity analysis of two links flexible arm with three degrees of freedom

2003 ◽  
Author(s):  
T. Fukuda ◽  
A. Arakawa
Keyword(s):  
Optimal Control ◽  
Sensitivity Analysis ◽  
Degrees Of Freedom ◽  
Flexible Arm ◽  
Three Degrees Of Freedom

scholarly journals Control of Three Degrees-of-Freedom Wave Energy Converters Using Pseudo-Spectral Methods

2018 ◽  
Vol 140 (7) ◽  
Author(s):  
Ossama Abdelkhalik ◽  
Shangyan Zou ◽  
Rush Robinett ◽  
Giorgio Bacelli ◽  
David Wilson ◽  
...  
Keyword(s):  
Optimal Control ◽  
Wave Energy ◽  
Parametric Excitation ◽  
Degrees Of Freedom ◽  
Closed Form Solution ◽  
Form Solution ◽  
Programming Approach ◽  
Wave Energy Converters ◽  
Pseudo Spectral ◽  
Three Degrees Of Freedom

Abstract This paper presents a solution to the optimal control problem of a three degrees-of-freedom (3DOF) wave energy converter (WEC). The three modes are the heave, pitch, and surge. The dynamic model is characterized by a coupling between the pitch and surge modes, while the heave is decoupled. The heave, however, excites the pitch motion through nonlinear parametric excitation in the pitch mode. This paper uses Fourier series (FS) as basis functions to approximate the states and the control. A simplified model is first used where the parametric excitation term is neglected and a closed-form solution for the optimal control is developed. For the parametrically excited case, a sequential quadratic programming approach is implemented to solve for the optimal control numerically. Numerical results show that the harvested energy from three modes is greater than three times the harvested energy from the heave mode alone. Moreover, the harvested energy using a control that accounts for the parametric excitation is significantly higher than the energy harvested when neglecting this nonlinear parametric excitation term.

scholarly journals A Measurement Device for Rotational Stiffness of the Eye

2008 ◽  
Vol 2 (2) ◽  
Author(s):  
Thijs R. de Graaf ◽  
Sander Schutte ◽  
Huib J. Simonsz ◽  
Arthur G. Erdman ◽  
Frans C. T. van der Helm ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Degrees Of Freedom ◽  
Strabismus Surgery ◽  
Horizontal Position ◽  
Linkage Mechanism ◽  
Rotational Stiffness ◽  
Measurement Device ◽  
Interindividual Differences ◽  
Outcome Of Surgery ◽  
Three Degrees Of Freedom

Objective: A measurement of rotational stiffness of the human eye is necessary, without exerting forces to the eye. Background: Strabismus is a disorder in which the visual axes of the eyes are misaligned. In strabismus surgery, the muscles that drive the eye are altered to compensate for the deviating angle of the eye. Unfortunately, between 20% and 50% of these operations need resurgery. A sensitivity analysis has suggested that one cause for an erroneous outcome of surgery is due to interindividual differences in rotational stiffness induced by tissue surrounding the eye. Methods and Results: A measurement device comprising a moment transferring linkage mechanism was developed. A moment is transferred to the eye without imposing a stationary point of rotation. The mechanism is attached to the eye and has three degrees of freedom. The eye is free to rotate under the applied moment. The applied moment and the resulting angle are measured to calculate the rotational stiffness of the eye. Parasitic forces are minimized by keeping friction, inertia and stiffness in the mechanism to a minimum. In addition, the three degrees of freedom of the mechanism are statically balanced. Conclusion: Preliminary tests have shown the feasibility of the measurement in a sterile environment in people that are in horizontal position.

scholarly journals Optimal control of a two-wheeled mobile robot: Simulation for selecting of the motors

2003 ◽  
Vol 16 (1) ◽  
pp. 55-65
Author(s):  
Milovan Radulovic ◽  
Dejan Popovic ◽  
Novak Jaukovic
Keyword(s):  
Optimal Control ◽  
Dynamic Programming ◽  
Mobile Robot ◽  
Degrees Of Freedom ◽  
Tracking Error ◽  
Mathematic Model ◽  
Discrete Mathematic ◽  
Inertia Properties ◽  
Three Degrees Of Freedom ◽  
Selection Of

This paper presents how a novel simulation package for optimal control based on dynamic programming can be used for selecting the drives once the constraints are known: range of speeds, trajectory (minimum radius for turns), load that will be carried by the mobile robot and its position on the platform (inertia! properties of the mobile robot with the load). We calculate the necessary driving torques at the wheels of the mobile robot for various trajectories having a shape of the figure eight within a given time. The simulation uses fully customized dynamic model of the mobile robot that is propelled by two independent wheels and has third non-powered wheel that freely rotates around the vertical shaft to ensure three degrees of freedom. Dynamic programming and the discrete mathematic model allow simulation of the non-holonomic system. We presented in this paper only one possible application, that is, the analysis of three different loads carried along the same trajectory. The simulation clearly shows the relation between the tracking error and required diving torque; thereby, allow selection of the adequate driving motors for a given load and vice versa.

scholarly journals Active Disturbance Rejection for a Three Degrees of Freedom Gyroscope

2018 ◽  
Vol 51 (13) ◽  
pp. 372-377 ◽  
Author(s):  
Juan E. Andrade García ◽  
Alejandra Ferreira de Loza ◽  
Luis T. Aguilar ◽  
Ramón I. Verdés
Keyword(s):  
Disturbance Rejection ◽  
Degrees Of Freedom ◽  
Active Disturbance Rejection ◽  
Three Degrees Of Freedom

scholarly journals Sensitivity analysis and optimal control of COVID-19 dynamics based on SEIQR model

2021 ◽  
Vol 22 ◽  
pp. 103956
Author(s):  
Takasar Hussain ◽  
Muhammad Ozair ◽  
Farhad Ali ◽  
Sajid ur Rehman ◽  
Taghreed A. Assiri ◽  
...  
Keyword(s):  
Optimal Control ◽  
Sensitivity Analysis
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