Parameter Synthesis Algorithm Research Articles

Synthesis of Control Systems with Sign-To-Effect Compensating Feedback in Conditions of Limited Uncertainty

The algorithm of structural and parametric synthesis of automatic control systems for limitedly uncertain non-linear objects with unstable balance status and right own values in their exit matrix is proposed. The pecu-liarity of the structural synthesis algorithm is that synthesized automatic control systems use differential com-pensating connection with two components. The signal of one of them is proportional to the signal of disa-greement between the required and measured values of the state vector of the system. A signal of another com-ponent is formed by the sign-operated integral feedback on the module of the control influence. The algorithm of parametric synthesis is reduced to solving the problem at a conditional minimum of integral regulatory error when limiting the characteristic frequency multi-member module to an algorithmically linearized system.

Parallel parameter synthesis algorithm for hybrid CTL

• We deal with parametrised models that appear in various areas of science. • We focus on properties specified in a hybrid extension of CTL. • We provide a novel semi-symbolic parallel parameter synthesis algorithm. Parametrised models of dynamical systems arise in various areas of science. In this work, we focus on models described as parametrised Kripke structures with properties formulated in a hybrid extension of the Computation Tree Logic. Our goal is to identify all the parametrisations under which the given model satisfies the properties. To that end, we propose a novel semi-symbolic parallel parameter synthesis algorithm. The algorithm is built on top of an existing approach that utilises the so-called Extended Dependency Graphs. We extend this approach to deal with parameters. To demonstrate the usefulness of our approach, we show its application to several case studies taken from systems biology.

THE PARAMETRIC SYNTHESIS OF THE C5M COSMIC STAGE STABILIZER OF THE CYCLONE-3 CARRIER ROCKET IN THE ACTIVE PART OF TRAJECTORY

The problem of choosing the numerical values of the variable parameters of the stabilizer of the C5M cosmic stage of the Cyclone-3 carrier rocket in the active part of the trajectory is considered. Currently, to solve the parametric synthesis problems of analog and digital regulators of non-stationary dynamic objects, the “frozen coefficients” method is used, according to which the active part of the flight trajectory is divided into separate sections, at each of which the mass, inertial and geometric characteristics of the stage are considered constant, in words, at each moment in time, the values of the coefficients of the coefficients of the mathematical model of the perturbed vision stage, as well as the value of disturbing forces and moments acting on the stage. It is assumed that the stability of the stage at each moment of the active part of the flight ensures the stability of the flight in the active area as a whole. This method, firstly, does not have a rigorous mathematical justification and, secondly, is not able to provide continuously increasing requirements for the accuracy of regulators. The method of parametric synthesis of regulators of non-stationary objects set out in this article is based on finding the values of the variable parameters of the regulator delivering a minimum to the integral quadratic functional calculated on the solutions of the mathematical model of a closed control system. In this case, the parametric synthesis algorithm includes a targeted choice of the functional weighting coefficients, and the minimum of the functional is searched for using the Optimization Toolbox software in the MATLAB or the Minimize software in the MATHCAD. The proposed method of parametric synthesis of the stabilizer allows to increase the speed of the closed stabilization system and significantly reduce the static error of the lateral displacement of the center of mass. A comparative research of the stabilization processes of the C5M cosmic stage of the Cyclone-3 carrier rocket with a standard stabilizer and a stabilizer synthesized by the proposed method leads to the conclusion that the accuracy of the stabilization of the cosmic stage is significantly improved when using the above parametric synthesis method.

SYNTHESIS OF CONTROLLERS FOR NONLINEAR CONTROL OBJECTS ON BASIS OF NUMERICAL METHODS FOR SOLVING DIFFERENTIAL EQUATIONS

The algorithm of parametric synthesis of regulators for nonlinear control objects is presented in the article, in which knowledge of the real trajectory of the system motion is not required in an explicit form. The essence of the algorithm is as follows: the dynamic properties of the control system are always determined by the right-hand side of the system of differential equations written in the normal form of Cauchy. Depending on the values of the regulator parameters that are also included in the right-hand side, the system of equations may have one or another solution. If we substitute the reference trajectory into the scheme of numerical integration of differential equations describing the dynamics of the system, then at each step of integration it can be considered as a system of algebraic equations for the desired parameters of the regulator. For each discrete value of the reference signal, there is a set of desired regulator parameters from which the desired values are determined, for example, as weighted averages over the entire study interval, or, as some limiting values. In the proposed algorithm, in an implicit form, the criterion of optimality is the norm in the space of convergent numerical sequences.

On clock-aware LTL parameter synthesis of timed automata

The parameter synthesis problem for timed automata is undecidable in general even for very simple reachability properties. In this paper we introduce restrictions on parameter valuations under which the parameter synthesis problem is decidable for Clock-Aware LTL properties. The investigated bounded integer parameter synthesis problem could be solved using an explicit enumeration of all possible parameter valuations. We propose an alternative symbolic zone-based method for this problem which can result in a faster computation. Our technique adapts the ideas of the automata-based approach to Clock-Aware LTL model checking of timed automata. In order to simplify the explanation of our method, we first introduce a parameter synthesis algorithm for timed automata, then we describe method for checking Clock-Aware LTL properties of timed automata and finally we combine these two methods together to provide general parameter synthesis algorithm for Clock-Aware LTL properties. To demonstrate the usefulness of our approach, we provide experimental evaluation and compare the proposed method with the explicit enumeration technique.

Synthesis of Nonlinear Systems with Compensating Feedback Over the State Vector in Restricted Uncertainty Conditions

A method for the synthesis of automatic control systems for functionally indeterminate nonlinear objects of the n-th order with a mathematical model in the form of differential equations in normal form is proposed. Control objects may have an unstable state of equilibrium, and their output matrix may contain right eigenvalues. In this case, the algorithm of structural synthesis is based on specifying the required equation of motion of the system and solving the inverse problem of dynamics using the observer of state variables and compensating coupling according to the deviation of the state vector of the synthesized and reference system. The algorithm of parametric synthesis is reduced to the solution of the problem on the conditional minimum of the integral error of regulation when the algorithmic linearized system is restricted to the modulus of the characteristic frequency polynomial

АДАПТИВНЫЙ АЛГОРИТМ ПАРАМЕТРИЧЕСКОГО СИНТЕЗА КОМБИНИРОВАННЫХ ДИНАМИЧЕСКИХ СИСТЕМ

АДАПТИВНЫЙ АЛГОРИТМ ПАРАМЕТРИЧЕСКОГО СИНТЕЗА КОМБИНИРОВАННЫХ ДИНАМИЧЕСКИХ СИСТЕМ

Hardware-in-the-loop simulation and energy optimization of cardiac pacemakers.

Implantable cardiac pacemakers are medical devices that can monitor and correct abnormal heart rhythms. To provide the necessary safety assurance for pacemaker software, both testing and verification of the code, as well as testing the entire pacemaker hardware in the loop, is necessary. In this paper, we present a hardware testbed that enables detailed hardware-in-the-loop simulation and energy optimisation of pacemaker algorithms with respect to a heart model. Both the heart and the pacemaker models are encoded in Simulink/Stateflow™ and translated into executable code, with the pacemaker executed directly on the microcontroller. We evaluate the usefulness of the testbed by developing a parameter synthesis algorithm which optimises the timing parameters based on power measurements acquired in real-time. The experiments performed on real measurements successfully demonstrate that the testbed is capable of energy minimisation in real-time and obtains safe pacemaker timing parameters.

On Parameter Synthesis by Parallel Model Checking

An important problem in current computational systems biology is to analyze models of biological systems dynamics under parameter uncertainty. This paper presents a novel algorithm for parameter synthesis based on parallel model checking. The algorithm is conceptually universal with respect to the modeling approach employed. We introduce the algorithm, show its scalability, and examine its applicability on several biological models.

Robust parameter synthesis for planar higher pair mechanical systems

We present a parameter synthesis algorithm for planar, higher pair mechanical systems. The input is a parametric model of a mechanical system (part shapes and configurations) with nominal values and tolerance intervals for the parameters. The output is revised parameter ranges that guarantee correct kinematic function for all system variations. Nominal values are changed when possible and tolerance intervals are shrunk as a last resort. The algorithm consists of a three-step cycle that detects and eliminates system variations with incorrect kinematic function. The first step finds points in parameter space whose kinematic variation is maximal. The maximum of the higher pairs are derived by contact zone construction and are then combined into system maximums. The second step tests the points for correct kinematic function using configuration space matching and kinematic simulation. The third step adjusts the parameter ranges to exclude the points that fail the test. The cycle repeats until every point exhibits correct function. We demonstrate the algorithm on five real-world examples.

Parameter synthesis of higher kinematic pairs

We describe a parameter synthesis algorithm for planar mechanical systems comprised of higher kinematic pairs in which each part translates along a fixed axis or rotates around a fixed point. This is an important class of systems and is not addressed by prior synthesis research. Kinematic function is computed from the CAD models of the parts and is represented graphically as configuration spaces. Design flaws appear as incorrectly shaped contact curves, as incorrectly placed intersection points, and as incorrect curve sequences. The designer reshapes the faulty curves with the keyboard mouse. The synthesis algorithm computes new parameter values that realize the changes without harmful side effects, using a novel form of constrained optimization. The algorithm has been tested on industrial applications.