Optimal Control Discipline Research of Hydraulic System of Sugarcane Harvester

2011 ◽  
Vol 199-200 ◽  
pp. 1281-1286
Author(s):  
Yi Zhi Hu ◽  
Ying Chun Hu ◽  
Jun Yan Hou ◽  
Hui Zhu
Keyword(s):  
Optimal Control ◽  
Minimum Principle ◽  
Control Valve ◽  
Flow Control Valve ◽  
State Equations ◽  
Controlling System ◽  
Spring Force ◽  
Time Optimal ◽  
Sugarcane Harvester ◽  
Theory Base

The actiyator of chassis mechanism of sugarcane harvester was a cubage flow regulation circuit consisted of a timing variable pump and a compensated flow control valve. The optimal controlling system described its movement from processing time using differential and state equations. The shortest-time optimal controlling trajectory of spring force of the variable pump was a group of concentric circles based on minimum principle, which controlling signal switched on origin trajectory. Under the condition of optimal control, the stator was pushed by spring to a new balance spot which left off origin 15.5 millimeter in the shortest time of 1.12 seconds, which provided theory base to further controlling system design. Its stability and validity has been proved well in physical product research.

Time-optimal control of multiple unmanned aerial vehicles with human control input

2019 ◽  
Vol 12 (1) ◽  
pp. 138-152 ◽  
Author(s):  
Tao Han ◽  
Bo Xiao ◽  
Xi-Sheng Zhan ◽  
Jie Wu ◽  
Hongling Gao
Keyword(s):  
Optimal Control ◽  
Optimal Control Problems ◽  
Minimum Principle ◽  
Time Optimal Control ◽  
Control Problems ◽  
Control Input ◽  
Content Type ◽  
Human Control ◽  
Time Optimal ◽  
The Cost

Purpose The purpose of this paper is to investigate time-optimal control problems for multiple unmanned aerial vehicle (UAV) systems to achieve predefined flying shape. Design/methodology/approach Two time-optimal protocols are proposed for the situations with or without human control input, respectively. Then, Pontryagin’s minimum principle approach is applied to deal with the time-optimal control problems for UAV systems, where the cost function, the initial and terminal conditions are given in advance. Moreover, necessary conditions are derived to ensure that the given performance index is optimal. Findings The effectiveness of the obtained time-optimal control protocols is verified by two contrastive numerical simulation examples. Consequently, the proposed protocols can successfully achieve the prescribed flying shape. Originality/value This paper proposes a solution to solve the time-optimal control problems for multiple UAV systems to achieve predefined flying shape.

Determining Model Accuracy Requirements for Automotive Engine Coldstart Hydrocarbon Emissions Control

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
Nasser L. Azad ◽  
Pannag R. Sanketi ◽  
J. Karl Hedrick
Keyword(s):  
Optimal Control ◽  
Sensitivity Analysis ◽  
Real Time ◽  
Minimum Principle ◽  
Optimal Solution ◽  
Control Performance ◽  
Automotive Engine ◽  
Engine Model ◽  
Time Optimal ◽  
Hc Emissions

In this work, a systematic method is introduced to determine the required accuracy of an automotive engine model used for real-time optimal control of coldstart hydrocarbon (HC) emissions. The engine model structure and development are briefly explained and the model predictions versus experimental results are presented. The control design problem is represented with a dynamic optimization formulation on the basis of the engine model and solved using the Pontryagin’s minimum principle (PMP). To relate the level of plant/model mismatch and the control performance degradation in practice, a sensitivity analysis using a computationally efficient method is employed. In this way, the sensitivities or the effects of small parameter variations on the optimal solution, which is the minimum of cumulative tailpipe HC emissions over the coldstart period, are calculated. There is a good agreement between the sensitivity analysis results and the experimental data. The sensitivities indicate the directions of the subsequent parameter estimation and model improvement tasks to enhance the control-relevant accuracy, and thus, the control performance. Furthermore, they provide some insights to simplify the engine model, which is critical for real-time implementation of the coldstart optimal control system.

scholarly journals An iterative method for time optimal control of dynamic systems

2011 ◽  
Vol 21 (1) ◽  
pp. 5-23 ◽  
Author(s):  
Navvab Kashiri ◽  
Mohammad Ghasemi ◽  
Morteza Dardel
Keyword(s):  
Optimal Control ◽  
Iterative Method ◽  
Dynamic Systems ◽  
Minimum Principle ◽  
Minimum Energy ◽  
Optimal Solution ◽  
Initial Guess ◽  
Open Loop ◽  
Time Optimal Control ◽  
Time Optimal

An iterative method for time optimal control of dynamic systemsAn iterative method for time optimal control of a general type of dynamic systems is proposed, subject to limited control inputs. This method uses the indirect solution of open-loop optimal control problem. The necessary conditions for optimality are derived from Pontryagin's minimum principle and the obtained equations lead to a nonlinear two point boundary value problem (TPBVP). Since there are many difficulties in finding the switching points and in solving the resulted TPBVP, a simple iterative method based on solving the minimum energy solution is proposed. The method does not need finding the switching point so that the resulted TPBVP can be solved by usual algorithms such as shooting and collocation. Also, since the solution of TPBVPs is sensitive to initial guess, a short procedure for making the proper initial guess is introduced. To this end, the accuracy and efficiency of the proposed method is demonstrated using time optimal solution of some systems: harmonic oscillator, robotic arm, double spring-mass problem with coulomb friction and F-8 aircraft.

Guess-Free Pseudospectral Solution for Time Optimal Swing-Up of a Rotary Inverted Pendulum

2017 ◽  
Author(s):  
Paul J. Frontera ◽  
Matthew Feemster ◽  
Michael Hurni ◽  
Mark Karpenko
Keyword(s):  
Optimal Control ◽  
Inverted Pendulum ◽  
Minimum Principle ◽  
Problem Formulation ◽  
Fixed Time ◽  
Time Problem ◽  
Time Optimal ◽  
Switching Structure ◽  
Original Time ◽  
Rotary Inverted Pendulum

Control of the inverted pendulum is a canonical problem in nonlinear and optimal control. Over the years, many workers have developed solutions for inverting the pendulum link (swing-up phase) and for maintaining the pendulum link upright (stabilization/disturbance rejection). In this paper, the time-optimal swing-up of a rotary inverted pendulum is studied. Previous solutions to this problem have required that the original time-optimal problem formulation be transformed to a more computationally tractable form. For example, one transformation is to a fixed-time problem with bounds on the control. Other approaches involve guessing the switching structure in order to construct a candidate solution. Advances in computational optimal control theory, particularly pseudospectral optimal control, allow the original time-optimal problem to be solved directly, and without the need for a guess. One such solution is presented in this paper. It is shown that the result adheres to the conditions of Pontryagin’s minimum principle. An experimental implementation of the solution illustrates its feasibility in practice.

Trajectory Planning for Tricycle Mobile Manipulator With Moving Boundary Conditions Using Optimal Control Approach

2010 ◽  
Author(s):  
Moharam H. Korayem ◽  
Mojtaba Abolhasani ◽  
Vahid Azimirad ◽  
Hassan Ansari
Keyword(s):  
Optimal Control ◽  
Boundary Conditions ◽  
Moving Boundary ◽  
Control Method ◽  
Minimum Principle ◽  
Optimal Path ◽  
Product Line ◽  
Mobile Manipulator ◽  
State Equations ◽  
Control Approach

In the present paper optimal path of the tricycle nonholonomic robot with two-link manipulator, obeying a particular equation with moving boundary conditions is obtained. These boundary conditions are a set of points that are called the moving boundaries. One of the main applications of this method is handling and transporting parts from one place to another by employing the aid of robot with cable strip. For example, for putting the tools and industrial parts in proper places in the product line, the reductions of time, cost and energy are guaranteed by a precise schematization and defining the best path. The methodology uses optimal control for finding optimum path. To do this, the dynamics and kinematic equations of robot are derived. Then by applying the optimal control method and Pontryagin’s minimum principle lead to deriving optimal conditions as a set of differential equations. Finally, will be solvable a boundary value problem. The formulation of the moving boundary for the tricycle robot using the optimal control includes state and co-state equations that replace the boundary conditions of the problem in the constant boundary state. As a result, solving the optimal path with moving boundary for minimization leads to obtaining a cost function that includes velocities and torques. Lastly, the simulation results of tricycle robot with two-link spatial mobile manipulator and moving boundary condition are presented that shows the accuracy and capability of the method.

scholarly journals Time-optimal control of infinite order hyperbolic systems with time delays

2009 ◽  
Vol 19 (4) ◽  
pp. 597-608 ◽  
Author(s):  
Adam Kowalewski
Keyword(s):  
Optimal Control ◽  
Time Delays ◽  
Infinite Order ◽  
Hyperbolic Systems ◽  
Integral Form ◽  
Adjoint System ◽  
Time Optimal Control ◽  
Optimal Controls ◽  
State Equations ◽  
Time Optimal

Time-optimal control of infinite order hyperbolic systems with time delaysIn this paper, the time-optimal control problem for infinite order hyperbolic systems in which time delays appear in the integral form both in state equations and in boundary conditions is considered. Optimal controls are characterized in terms of an adjoint system and shown to be unique and bang-bang. These results extend to certain cases of nonlinear control problems. The particular properties of optimal control are discussed.

scholarly journals Application of Minimum-time Optimal Control System in Buck-Boost Bi-linear Converters

2017 ◽  
Vol 7 (4) ◽  
pp. 1753-1758
Author(s):  
S. M. M. Shariatmadar ◽  
S. M. J. Jafarian
Keyword(s):  
Optimal Control ◽  
Control System ◽  
Output Voltage ◽  
Minimum Principle ◽  
Voltage Regulation ◽  
Minimum Time ◽  
Time Optimal Control ◽  
Optimal Switching ◽  
Optimal Control System ◽  
Time Optimal

In this study, the theory of minimum-time optimal control system in buck-boost bi-linear converters is described, so that output voltage regulation is carried out within minimum time. For this purpose, the Pontryagin's Minimum Principle is applied to find optimal switching level applying minimum-time optimal control rules. The results revealed that by utilizing an optimal switching level instead of classical switching patterns, output voltage regulation will be carried out within minimum time. However, transient energy index of increased overvoltage significantly reduces in order to attain minimum time optimal control in reduced output load. The laboratory results were used in order to verify numerical simulations.

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