scholarly journals Estimation of proximity of controls synthesized on basis of maximum principle and ADAR method

2019 ◽  
Vol 18 (4) ◽  
pp. 438-448
Author(s):  
V. P. Lapshin ◽  
I. A. Turkin ◽  
V. V. Khristoforova

Introduction.A special case of synthesizing the same electromechanical control system by the Pontryagin maximum principle and by the synergetic synthesis method is considered. The task was to solve the synthesis problem of the time optimal electromechanical position control system; herewith the travel resistance modulus linearly depended on the output coordinate of the system. This approach to the selection of the synthesis problem was because the synthesis of time optimal systems is one of the most widespread problems, and it is solved by increasing the efficiency of the existing control systems.Materials and Methods.Synthesis of the time optimal linear control system based on the maximum principle is a widely accepted problem in the modern control theory. However, the procedure of synergistic synthesis does not have such formalization. This being the case, the paper suggests an approach that brings together these two methods, which, in our opinion, will increase the efficiency of the synergistic synthesis method through adding some features of the synthesis methodology for optimal systems.Research Results.The paper formulates two key concepts. The first one is as follows: the application of the maximum principle for an object of the DC motor class when synthesizing the positioning algorithm under the conditions of linear loading functionally dependent on the engine rotation angle allows the time optimal system to be optimized. The second concept states that synthesis of a control system based on the synergistic approach enables to obtain a system close to optimal (quasioptimal), but after modifying the synergetic synthesis method itself. A hypothesis is formulated on the possible connection between the introduced (when implementing the procedure of state space extension in the synergetic synthesis method) time constants with the optimal switching time of control defined in the maximum method.Discussion and Conclusions.The synthesis through the maximum control technique and the ADAR method is performed. In virtue of the comparison of efficiency of these methods, a hypothesis is put forward on the possible compatibility of the studied methods.

2018 ◽  
Vol 226 ◽  
pp. 02012 ◽  
Author(s):  
Viktor P. Lapshin ◽  
Ilya A. Turkin ◽  
Alexey A. Zakalyuzhnyy ◽  
Viktor F. Khlystunov ◽  
Gennadiy A. Kuzin

A special case of synthesizing the electromechanical control system by the maximum method and using the Analytical Construction method of Aggregate Regulators (ACAR) is considered in the article. For the basis the task of synthesizing the optimal for speed electromechanical positioning system was chosen, while the moment of resistance to movement linearly depended on the output coordinate of the system, that is, on the angle of the engine rotor rotation. Synthesis of the optimal system for speed makes it possible to increase the efficiency of the entire production process in many production tasks, and the synthesis of the optimal linear control system based on the maximum principle is a fairly well-formalized problem. Here it should be noted that the procedure for synergistic synthesis of the optimal control system has no such formalization. An approach that brings together the solutions obtained by these two methods, which makes it possible to increase the efficiency of the ACAR method by adding some features of the methodology for synthesizing optimal systems by introducing nonlinearity of the “saturation” type is proposed in the article. The results obtained made it possible to formulate the following basic scientific proposition: the synthesis of a control system based on the synergetic approach makes it possible to obtain a system close to optimal (quasi-optimal, but after the modification of the synergetic synthesis method itself.) Here we also formulate the hypothesis of a connection between the time constants, using the ACAR method, with the optimal control switching time determined in the maximum method.


2019 ◽  
Vol 25 ◽  
pp. 20
Author(s):  
Eero V. Tamminen

We examine discrete-time optimal control problems with general, possibly non-linear or non-smooth dynamic equations, and state-control inequality and equality constraints. A new generalized convexity condition for the dynamics and constraints is defined, and it is proved that this property, together with a constraint qualification constitute sufficient conditions for the strong Lagrange duality result and saddle-point optimality conditions for the problem. The discrete maximum principle of Pontryagin is obtained in a straightforward manner from the strong Lagrange duality theorem, first in a new form in which the Lagrangian is minimized both with respect to the state and to the control variables. Assuming differentiability, the maximum principle is obtained in the usual form. It is shown that dynamic systems satisfying a global controllability condition with convex costs, have the required convexity property. This controllability condition is a natural extension of the customary directional convexity condition applied in the derivation of the discrete maximum principle for local optima in the literature.


Electronics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 462
Author(s):  
Hwan-Cheol Park ◽  
Soumayya Chakir ◽  
Young-Bok Kim ◽  
Dong-Hun Lee

This paper presents a robust controller design of payload position control for an offshore crane facing disturbance and parametric uncertainties. The offshore operations with cranes while lifting and lowering a payload can be dangerous since safety and efficiency are affected by waves, wind and ocean currents. Such harsh sea conditions put the offshore crane and payload through unwanted disturbances and parametric uncertainties, which requires a robust control system to guarantee reliable performance of these systems. In this paper, we detail a controller designed based on uniformly ultimately bounded (UUB) theory, combined with the input-output linearization control technique (IOLC). The stability of the closed-loop system under the UUB conditions is analyzed using the energy-based Lyapunov function. To evaluate the control performance of the proposed controller, along with an IOLC and an integral sliding mode controller (ISMC), a comparison study is also conducted. The control performance and efficiency of the proposed controller are validated through experiments on an offshore crane model.


2021 ◽  
Vol 24 (4) ◽  
pp. 217-229
Author(s):  
V. A. Porkhalo ◽  
V. G. Rubanov ◽  
A. G. Bazhanov ◽  
О. V. Lutcenko

Purpose of research. The purpose of this study is to assess the possibility of developing and simulating an optimal control system for the longitudinal movement of a robocars according to the criterion of maximum speed by using the MSC.Adams virtual modeling system and the MATLAB mathematical modeling package Methods. One of the research approaches is system modeling, while a virtual modeling system is used as a software tool for synthesizing a virtual physical model of a robot, and a package of application programs for solving technical computing problems MATLAB and a graphical environment for simulation Simulink are used to model a control system. The Pontryagin maximum principle is used as a synthesis method for the longitudinal displacement control system, and the maximum speed is used as an optimality criterion. Results: The structure of the control system for a robotic platform is presented; an optimal control algorithm is developed and implemented in the Simulink environment. The structure of the physical model management system with data transfer to Adams has been developed. The acceleration curves and the phase portrait of the model control system during the longitudinal movement of the robotic platform are presented and analyzed. Conclusion. As can be seen from the above simulation results, the optimal positional control law, which implements the maximum principle, fulfills the task with the required quality indicators. In this regard, the proposed algorithm can be used in the development of control systems for the longitudinal movement of mobile robots. Joint modeling of the virtual prototype and the object control system in the Matlab and Adams environment avoids the production of a fullscale model and makes it possible to take into account the physical properties of the object without creating an analytical model.


Author(s):  
Debargha Chakraborty ◽  
Binanda Kishore Mondal ◽  
Souvik Chatterjee ◽  
Sudipta Ghosh

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