We study the problem of automatic generation of smooth and obstacle-avoiding planar paths for efficient guidance of autonomous mining vehicles. Fast traversal of a path is of special interest. We consider four-wheel four-gear articulated vehicles and assume that we have an a priori knowledge of the mine wall environment in the form of polygonal chains. Computing quartic uniform B-spline curves, minimizing curvature variation, staying at least at a proposed safety margin distance from the mine walls, we plan high speed paths.

Airport baggage handling is a field of automation systems that is currently dependent on centralized control systems and conventional automation programming techniques. In this and other areas of manufacturing and materials handling, these legacy automation technologies are increasingly limiting for the growing demand for systems that are reconfigurable, fault tolerant, and easy to maintain. IEC 61499 Function Blocks is an emerging architectural framework for the design of distributed industrial automation systems and their reusable components. A number of architectures have been suggested for multiagent and holonic control systems that incorporate function blocks. This paper presents a multiagent control approach for a baggage handling system (BHS) using IEC 61499 Function Blocks. In particular, it focuses on demonstrating a decentralized control system that is scalable, reconfigurable, and fault tolerant. The design follows the automation object approach, and produces a function block component representing a single section of conveyor. In accordance with holonic principles, this component is autonomous and collaborative, such that the structure and the behavior of a BHS can be entirely defined by the interconnection of these components within the function block design environment. Simulation is used to demonstrate the effectiveness of the agent-based control system and a utility is presented for real-time viewing of these systems. Tests on a physical conveyor test system demonstrated deployment to embedded control hardware.

The IEC 61499 Function Block architecture is considered as the next generation of programmable control technology promoting distributed control in automation. In this paper, the redesign methodologies from the PLC control to the event-driven architecture of IEC 61499 function blocks are proposed. A general set of translation steps and mapping rules for redesigning applications from IEC 61131-3 PLC to IEC 61499 Function Blocks is provided. Three different redesign approaches are proposed: object-oriented conversion approach, object-oriented reuse approach, and class-oriented approach. These approaches are to be applied for different design styles of the source PLC code. The data handling efficiency of all approaches is investigated. An airport baggage handling system is chosen as the case study for the redesign process. The rules and limitations are summarized and guidelines for the redesign process are provided.

We address the problem of estimating the number of people in a room using information available in standard HVAC systems. We propose an estimation scheme based on two phases. In the first phase, we assume the availability of pilot data and identify a model for the dynamic relations occurring between occupancy levels, CO2 concentration and room temperature. In the second phase, we make use of the identified model to formulate the occupancy estimation task as a deconvolution problem. In particular, we aim at obtaining an estimated occupancy pattern by trading off between adherence to the current measurements and regularity of the pattern. To achieve this goal, we employ a special instance of the so-called fused lasso estimator, which promotes piecewise constant estimates by including an l(1) norm-dependent term in the associated cost function. We extend the proposed estimator to include different sources of information, such as actuation of the ventilation system and door opening/closing events. We also provide conditions under which the occupancy estimator provides correct estimates within a guaranteed probability. We test the estimator running experiments on a real testbed, in order to compare it with other occupancy estimation techniques and assess the value of having additional information sources

IEC 61499 provides a standardized approach for the development of distributed control systems. The standard introduces a component architecture, based on function blocks that are event-triggered components processing data and signals. However, it gives only limited support for the design of reconfigurable architectures. In particular, handling of several reconfiguration scenarios is quite heavy on this level since a scenario changes the execution model of the system due to requirements. To this end, a new IEC 61499-based model named reconfigurable function blocks (RFBs) is proposed. An RFB processes the reconfiguration events and switches directly to the suitable configuration using a hierarchical state machine model. The latter represents the reconfiguration model which reacts on changes in the environment in order to find an adequate reconfiguration scenario to be executed. Each scenario presents a particular sequence of algorithms, encapsulated in another execution control chart slave which represents the control model of an RFB. This hierarchy simplifies the design and separates the reconfiguration logic from control models. To verify its correctness and alleviate its state space explosion problem in model checking, this paper translates an RFB system automatically into a generalized model of reconfigurable timed net condition/event systems (GR-TNCES), a Petri net class that preserves the semantics of an RFB system. In this paper, along with verification of deterministic properties, we also propose to quantify and analyze some probabilistic properties. As a case study, we consider a smart-grid system, interpreting permanent faults in it as reconfiguration events, and we characterize them with the expected occurrence probability and the corresponding repair time. A tool chain ZiZo is developed to support the proposed approach.

Recent technological advances and manufacturing paradigm evolutions in industrial settings will dramatically increase the complexity of automation control systems. Traditional solutions to the software development of low-level control kernels (e.g., numerical control kernel, motion control kernel, and real-time communication tasks) are unable to cope effectively with such complexity due to an inadequate level of abstraction and challenges for dependability. This article presents a formal semantics integrated model-driven design approach as a holistic solution. A domain-specific modeling language (DSML) is specified based on the adaption of IEC 61 499 architecture, along with the extensions of task model, task-to-resource allocation, and nonfunctional specification. Both formal structural and behavioral semantics of the proposed DSML are then explicitly defined. Design-time formal verification is also achieved by automated model transformations. A metaprogrammable environment is adopted to facilitate flexible modeling, verification, and code generation. A case study is demonstrated on implementing a prototype computer numerical control (CNC) system using the proposed solution. Note to Practitioners —The low-level automation control system in the modern manufacturing scenarios require more agility while respecting strict timing constraints. Handling such complexity with manual coding is getting harder and less efficient. The DSML and the supporting development environment presented in this article aim to enhance the level of automation, flexibility, and dependability of the whole design process. For the proposed DSML, its syntax is formalized and defined as metamodels, while the semantics is integrated through model annotation and transformation. These definitions are implemented as external rules for a metaprogrammable environment to establish our proposed development tool. The finding and insight from this article can enhance efficiency and dependability during the development of common control kernels, such as CNC kernel and motion controller.