Diolino J. Santos Filho

Implantable centrifugal blood pump with dual impeller and double pivot bearing system: electromechanical actuator, prototyping, and anatomical studies.

An implantable centrifugal blood pump has been developed with original features for a left ventricular assist device. This pump is part of a multicenter and international study with the objective to offer simple, affordable, and reliable devices to developing countries. Previous computational fluid dynamics investigations and wear evaluation in bearing system were performed followed by prototyping and in vitro tests. In addition, previous blood tests for assessment of normalized index of hemolysis show results of 0.0054±2.46 × 10⁻³ mg/100 L. An electromechanical actuator was tested in order to define the best motor topology and controller configuration. Three different topologies of brushless direct current motor (BLDCM) were analyzed. An electronic driver was tested in different situations, and the BLDCM had its mechanical properties tested in a dynamometer. Prior to evaluation of performance during in vivo animal studies, anatomical studies were necessary to achieve the best configuration and cannulation for left ventricular assistance. The results were considered satisfactory, and the next step is to test the performance of the device in vivo.

Modeling of Programs and Its Verification for Programmable Logic Controllers

Abstract Programmable logic controller is still the main device used for control of productive systems, which can be approached as discrete event dynamic systems. For programming these controllers, five languages were standardized by IEC 61131, and the LD (ladder diagram) language is distinguished among the others, i.e., it has been widely applied in productive systems, even with studies that confirm the restrictions and problems regarding the use of this language, such as the difficulties for errors identification in developed control programs. Therefore, this work presents a proposal for the modeling of extended finite state machines from control programs written in LD. These models are verified through a computational tool, aiming the identification of possible errors in the control program.

Design of Active Holonic Fault-Tolerant Control Systems

The adequate evaluation of new technologies in productive systems that perform multiple and simultaneous processes, exploring the intense sharing of resources, demands the updating of supervision and control systems. On the other hand, totally infallible systems are unviable, and for a flexible productive system (FPS) does not to suffer interruptions due to component failure, the concept of AFTCS (active fault-tolerant control system) mechanism must be adopted. In this sense, holonic control system (HCS) is considered a trend for an intelligent automation and the combination of HCS techniques and AFTCS is fundamental to assure efficiency, flexibility and robustness of FPSs. Therefore, this work presents a procedure for the modeling of active holonic fault-tolerant control system (AHFTCS) that considers AFTCS’ requirements and interpreted Petri net for the description of the systems’ behavior. This method is applied to an intelligent building (IB) as a class of FPS and the results are presented.

An architecture based on IoT and CPS to organize and locate services

The fourth Industrial Revolution, also called Industry 4.0 (I4.0), has been increasing the expectation around productive systems. It is a new concept that has been changing the view and the value chain of enterprises. The I4.0 comprise the smart factory, bringing the emerging concepts of Internet of Things (IoT) and cyber-physical system (CPS) into manufacturing processes in a way to enable the design and creation of smart products, procedures and processes. Although, this scenario needs more investigation by the research and development fields, especially for architectures to guide the I4.0 implementation, mainly because it is in an initial stage and requires a comprehensive understanding to become a consolidated environment. The overall aim of this research is the presentation of an architecture based on IoT and CPS focused on I4.0. The proposal is centered on a hierarchical organization of services to contribute to the communication between machines and products so that products can be automatically guided in the manufacturing processes.

Modeling of Mechanisms for Reconfigurable and Distributed Manufacturing Control System

This paper presents the modeling of fault diagnosis mechanisms extending a method to design reconfigurable and distributed manufacturing control system. The method combines different techniques: service-oriented architecture, holonic and multi-agent system, production flow schema and input-output place-transition Petri net. An application example demonstrates advantages of the proposal, such as at cloud-based engineering, reuse, implementation and reconfiguration flexibility.

A method to design a manufacturing control system considering flexible reconfiguration

The manufacturing control system must immediately react to a variation in product, process specification, fault occurrence, changes in the resources functional capabilities, and other operational factors. Besides, to gain competitive advantage, distributed productive systems must work in cooperation with each other. To effectively integrate these heterogeneous envi-ronments, this paper proposes a method to combine holonic control system, service-oriented architecture and Petri net (PN) techniques. The PN models represent the workflow of the design method itself, the structure and the dynamic of the control system. To demonstrate the advantages of the proposal, an application example of the manufacturing system is described.

A Service-Oriented and Holonic Control Architecture to the Reconfiguration of Dispersed Manufacturing Systems

Manufacturing control systems must quickly react to variations of product, process specifications, fault occurrence, changes in the resources functional capabilities, and other operational demands. Besides, to gain competitive advantages, dispersed manufacturing systems must cooperate with each other. The combination of holonic control system and service-oriented architecture techniques can be effective to integrate these heterogeneous environments since the agents must also cooperate to achieve their services. Therefore, this paper introduces a service-oriented and holonic control architecture using Petri net to represent the workflow of design method itself, structure and dynamic of the entities. The modeling of an example is presented to demonstrate application at self-organization and adaptation, fault treatment, degeneration, and relatively shorter implementing time.

A Procedure for Modeling of Holonic Control Systems for Intelligent Building (HCS-IB)

Faults occurrence is inevitable in real world and a practical alternative approach is the reduction of fault consequences. Despite of this, the majority of buildings control systems do not have such mechanisms. Thus, this work proposes a procedure for the modeling of control systems for intelligent buildings which considers their functional specifications in normal operation, and in case of faults occurrence. The procedure adopts the concepts of discrete event system, holon, and Petri net and its extensions. It is presented some models derived from case studies, and mechanisms to fault-diagnosis, decision and reconfiguration.

Automatic generation of control solution for resource allocation using Petri net model

The flexible manufacturing system (FMS) executes multiple processes simultaneously using a limited set of resources. These processes can be blocked permanently due to the sequence of the activities, i.e., the processes sharing a finite set of resources may eventually lead to a deadlock state. The FMS belongs to the class of discrete event systems where it is not possible to determine when an event will occur and the sequence of events becomes undefined. Such systems can be modeled using Petri net, and this work presents a method that solves the deadlock problem considering the indeterminism of FMSs. The goal of this work is to introduce an algorithmic approach, which allows the implementation of a computer program based on FMS functional specification. The proposal is to automate the generation of the control strategy for resource utilization and the rules to avoid the deadlock situation.

Virtual Enterprise Planning System using time windows and capacity constraint concepts

In a global market, the trend for geographical dispersion of manufacturing plants has been observed. This dispersion is motivated by the opportunity to exploit local advantages under different viewpoints. This structure also allows for more intense interaction between plants of different productive enterprises. In this sense, the concept of Virtual Enterprise (VE) is fundamental to explore new business strategies such as “focus on core competencies”, “maximal customer orientation” and “distributed production”. However, in this new productive structure, there are new requirements for planning and for establishing the delivery date of the orders. To address these new requirements, this work introduces a Virtual Enterprise Planning System (VEPS) based on “time windows” and “capacity constraints”. These two concepts have been used extensively in the literature related to conventional planning systems: however, not in the VE context. In this approach, “time windows” delimit the allocation interval of the tasks in the production systems (PSs) involved, while “capacity constraint” makes the time windows feasible considering the importance of the due date.