A Fuzzy Virtual Actuator for Automated Guided Vehicles.

Ralf Stetter

doi:10.3390/s20154154

Abstract

In the last decades, virtual sensors have found increasing attention in the research community. Virtual sensors employ mathematical models and different sources of information such as actuator states or sensors, which are already existing in a system, in order to generate virtual measurements. Additionally, in recent years, the concept of virtual actuators has been proposed by leading researchers. Virtual actuators are parts of a fault-tolerant control strategy and aim to accommodate faults and to achieve a safe operation of a faulty plant. This paper describes a novel concept for a fuzzy virtual actuator applied to an automated guided vehicle (AGV). The application of fuzzy logic rules allows integrating expert knowledge or experimental data into the decision making of the virtual actuator. The AGV under consideration disposes of an innovative steering concept, which leads to considerable advantages in terms of maneuverability, but requires an elaborate control system. The application of the virtual actuator allows the accommodation of several possible faults, such as a slippery surface under one of the drive modules of the AGV.

Highlights

The flexibility and agility of production systems are of paramount importance because the complexity and diversity of most products are still increasing and production networks are more and more dynamic and internationally connected
This paper describes the design of a fuzzy virtual actuator for an automated guided vehicle
The central focus is the development of a system structure and algorithms for a control and diagnosis subsystem for an automated guided vehicle (AGV), which realizes a fuzzy virtual actuator

Summary

Introduction

The flexibility and agility of production systems are of paramount importance because the complexity and diversity of most products are still increasing and production networks are more and more dynamic and internationally connected. As conventional control solutions can lead to unsatisfactory performance or even instability [1], fault-tolerant control systems are proposed, which manage and compensate possible malfunction and faults of sensors, actuators and other internal and external system elements. This paper proposes a fuzzy virtual actuator for AGVs, which allows combining the information from more than one residual (an identified difference between an analytical model and a sensor reading) and the incorporation of expert knowledge. The central research question can be derived: How can a control and diagnosis subsystem for an AGV be developed, which realizes a fuzzy virtual actuator that uses the information of residuals created with an appropriate analytical model of the Sensors 2020, 20, 4154; doi:10.3390/s20154154 www.mdpi.com/journal/sensors

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