Finite State Machine

Centralized communication-based control is one of the main methods that can be implemented to achieve autonomous advanced energy management capabilities in DC microgrids. However, its major limitation is the fact that communication bandwidth and computation resources are limited in practical applications. This can be often improved by avoiding redundant communications and complex computations. In this paper, an autonomous communication-based hybrid state/event driven control scheme is proposed. This control scheme is hierarchical and heuristic, such that on the primary control level, it encompasses state-driven local controllers, and on the secondary control level, an event-driven MG centralized controller (MGCC) is used. This heuristic hybrid control system aims at reducing the communication load and complexity, processor computations, and consequently system cost while maintaining reliable autonomous operation during all possible scenarios. A mathematical model for the proposed control scheme using Finite State Machines (FSM) has been developed and used to cover all the possible modes/sub-modes of operation, and assure seamless transitions among them during various events. Results of some case studies involving severe operational scenarios were presented and discussed. Results verify the validity and effectiveness of the proposed communication-based control scheme. Index Terms—Communication-based control, DC microgrids, finite state machine, hybrid state/event driven control.

— The first part of paper discusses a variety of issues regarding finite state machine design using the hardware description language. VHDL coding styles and different methodologies are presented. Our study of FSM focuses on the modeling issues such as VHDL coding style, state encoding schemes and Mealy or Moore machines. Our discussion is limited to the synchronous FSM, in which the transition is controlled by a clock signal and can occur only at the triggering edge of the clock. The second part contains a worked example of a model that detects a unique pattern from a serial input data stream and generates a '1' value to output whenever the sequence '10' occurs. The string detector is modeled at the RTL level in VHDL and Verilog, for comparison purposes. The last part of this paper presents a view on VHDL and Verilog languages by comparing their similarities and contrasting their difference.

At the beginning of taking a shower, the user needs to manually adjust a rotational handle or the ratio of cold and hot water to get the desired water temperature and the flow rate. In this paper, a temperature and flow rate sensor feedback smart shower is proposed which takes the target water temperature and flow rate from the user as input, and then automatically adjusts the ratio of the cold and the hot water during the shower to keep the temperature and flow rate fixed-even though there is fluctuation of supply water temperature and pressure. The proposed system contains distance sensor and automatically turns off the shower when the user is away for soaping or shampooing. The system generates a report on water usage and shower time – to promote awareness on saving water. An embedded system based prototype of the proposed shower has been developed and tested.

— In this paper, an autonomous communication-based centralized control for DC microgrids (MG) has been developed and implemented. The proposed controller enables smooth transition between various operating modes. Finite state machine (FSM) has been used to mathematically describe the various operating modes (states), and the events that may lead to mode changes (transitions). Therefore, the developed centralized controller aims at optimizing the performance of MG during all possible operational scenarios, while maintaining its reliability and stability. Results of selected drastic cases have been presented. These results show stable transition between modes, verifying the validity and applicability of the proposed controller.

Abstract. This paper presents the methodology used to design a Domain Specific Visual Language (DSVL), named HALL (Human Assisted Logic Language), for the purpose of deriving automatically or semiautomatically user interfaces for critical control systems. We will describe our approach to design this language's abstract syntax and the process to describe its semantics by using formal framework based on an algebraic Petri-nets formalism: Concurrent Object-Oriented Petri Nets (CO-OPN). Keywords: Coordination- ...

Finite-state machines (FSMs) are among the oldest models employed in the formalization and analysis of both software and hardware. Owing to their simplicity, there exist various implementations to support their practical application in mainstream programming languages. Through such software libraries, programmers can explicitly define states, events and transitions in order to delegate the machine's execution to an underlying engine. However, as far as we know, no such library provides formal verification capabilities alongside its execution engine. That is to say, once an FSM is defined, the resulting program cannot be used as a formal specification to be subject to formal verification , thereby not making the analytical tractability of FSMs available. Formal verification, if any, is conducted in an independent model separate from the program, thus duplicating the information and creating the possibility of discrepancies between both. In this paper we show how to overcome this limitation. To this end, we present the Verum library, which allows the specification, execution and verification of FSMs in the Ruby language, largely bypassing the need to explicitly employ an additional modeling language. Formal verification is achieved by automatically translating the source program of the FSM into a Timed Automaton (TA) specification for the UPPAAL model checker. To illustrate the value of the approach, we present the industrial problem which inspired the creation of this tool and is currently using it, namely, a payment system. Besides the technical aspects of the tool, a number of practical lessons learned with this application are explored. Although we describe very concrete artifacts and applications, the overall approach is quite general.

The high way of presentation of entities or activities and relations which enterprises needed for their higher success and the powerful descriptive and representation method because of their complexity needed more and more in our days. In this paper, an approach for Business Process Modelling (BPM) using Hypergraphs representation based on Finite State Machines (FSM) will be presented. The main goal motives this work is the using of hypergraphs as a flexible mathematical structure describing Information System (IS) from various viewpoints to express the best graphical way for Business Process (BP) The model proposed use FSM as an automated formal model by defining concepts and components of the hypergraph elements based on different FSM patterns (simple, complex) to get representations can be analyzed by either using more traditional tools as logic and inference rules or by a set of tools belonging to data science later.

In this study we present a supervisory control system and implement it on a pneumatic system controlled by a PLC. We introduce a step-by-step implementation procedure including a realization methodology of finite state machines by PLCs. A hierarchical control structure is proposed and implemented. The pneumatic system control problem presented in this study is a typical logical Discrete Event System (DES) control problem, therefore it is easy to generalise the methodology for most of the DES control problems.

This paper shows how the behavior of a model described in the specification language proposed by the IEC 60848 standard can be represented, without semantics loss, in a formal manner, by a finite state machine (FSM) with logic inputs and outputs. This contribution is illustrated on a nontrivial example; this case study points out that the duration of the construction of the equivalent FSM complies with the requirements of designers of automation systems.

In the model-based development context, metamodel-based languages are increasingly being defined and adopted either for general purposes or for specific domains of interest. However, meta-languages such as the MOF (Meta Object Facility)—combined with the OCL (Object Constraint Language) for expressing constraints—used to specify metamodels focus on structural and static semantics but have no built-in support for specifying behavioral semantics. This paper introduces a formal semantic framework for the definition of the semantics of metamodel-based languages. Using metamodelling principles, we propose several techniques, some based on the translational approach while others based on the weaving approach, all showing how the Abstract State Machine formal method can be integrated with current metamodel engineering environments to endow language metamodels with precise and executable semantics. We exemplify the use of our semantic framework by applying the proposed techniques to the OMG metamodelling framework for the behaviour specification of the Finite State Machines provided in terms of a metamodel.