Temporal Logic Motion Planning

In this paper, a critical review on temporal logic motion planning is presented. The review paper aims to address the following problems: (a) In a realistic situation, the motion planning problem is carried out in real-time, in a dynamic, uncertain and ever-changing environment, and (b) The accomplishment of high-level specification tasks which are more than just the traditional planning problem (i.e., start at initial state A and go to the goal state B) are considered. The use of theory of computation and formal methods, tools and techniques present a promising direction of research in solving motion planning problems that are influenced by high-level specification of complex tasks. The review, therefore, focuses only on those papers that use the aforementioned tools and techniques to solve a motion planning problem. A proposed robust platform that deals with the complexity of more expressive temporal logics is also presented.Defence Science Journal, 2010, 60(1), pp.23-38, DOI:http://dx.doi.org/10.14429/dsj.60.9

Efficient Scheduling Rule for Robotic Flexible Assembly Cells Based on Fuzzy Approach

AbstractThis study aims to develop an efficient rule for scheduling robotic flexible assembly cells (RFACs). The proposed scheduling rule is called fuzzy sequencing rule (FSR) which is constructed by combining different input variables: processing time, due date, batch size and number of required assembly stations, using the fuzzy logic (FL) technique. Two independent performance measures are considered: makespan and maximum of tardiness. Simulation software named SIMPROCESS is used to examine the performance of FSR compared with existing scheduling rules. Simulation results show that the proposed rule outperforms the common scheduling rules

Intelligent Simulation Modeling of a Flexible Manufacturing System with Automated Guided Vehicles

Although simulation is a very flexible and cost effective problem solving technique, it has been traditionally limited to building models which are merely descriptive of the system under study. Relatively new approaches combine improvement heuristics and artificial intelligence with simulation to provide prescriptive power in simulation modeling. This study demonstrates the synergy obtained by bringing together the "learning automata theory" and simulation analysis. Intelligent objects are embedded in the simulation model of a Flexible Manufacturing System (FMS), in which Automated Guided Vehicles (AGVs) serve as the material handling system between four unique workcenters. The objective of the study is to find satisfactory AGV routing patterns along available paths to minimize the mean time spent by different kinds of parts in the system. System parameters such as different part routing and processing time requirements, arrivals distribution, number of palettes, available paths between workcenters, number and speed of AGVs can be defined by the user. The network of learning automata acts as the decision maker driving the simulation, and the FMS model acts as the training environment for the automata network; providing realistic, yet cost-effective and risk-free feedback. Object oriented design and implementation of the simulation model with a process oriented world view, graphical animation and visually interactive simulation (using GUI objects such as windows, menus, dialog boxes; mouse sensitive dynamic automaton trace charts and dynamic graphical statistical monitoring) are other issues dealt with in the study

Supervisory Control Theory for Controlling Swarm Robotics Systems

Swarm robotics systems have the potential to tackle many interesting problems. Their control software is mostly created by ad-hoc development. This makes it hard to deploy swarm robotics systems in real-world scenarios as it is difficult to analyse, maintain, or extend these systems. Formal methods can contribute to overcome these problems. However, they usually do not guarantee that the implementation matches the specification because the system’s control code is typically generated manually. This thesis studies the application of the supervisory control theory (SCT) framework in swarm robotics systems. SCT is widely applied and well established in the man- ufacturing context. It requires the system and the desired behaviours (specifications) to be defined as formal languages. In this thesis, regular languages are used. Regular languages, in the form of deterministic finite state automata, have already been widely applied for controlling swarm robotics systems, enabling a smooth transition from the ad-hoc development currently in practice. This thesis shows that the control code for swarm robotics systems can be automatically generated from formal specifications. Several case studies are presented that serve as guidance for those who want to learn how to specify swarm behaviours using SCT formally. The thesis provides the tools for the implementation of controllers using formal specifications. Controllers are validated on swarms of up to 600 physical robots through a series of systematic experiments. It is also shown that the same controllers can be automatically ported onto different robotics platforms, as long as they offer the required capabilities. The thesis extends and incorporates techniques to the supervisory control theory framework; specifically, the concepts of global events and the use of probabilistic generators. It can be seen as a step towards making formal methods a standard practice in swarm robotics

Robot planning based on boolean specifications using petri net models

In this paper, we propose an automated method for planning a team of mobile robots such that a Boolean-based mission is accomplished. The task consists of logical requirements over some regions of interest for the agents'' trajectories and for their final states. In other words, we allow combinatorial specifications defining desired final states whose attainment includes visits to, avoidance of, and ending in certain regions. The path planning approach should select such final states that optimize a certain global cost function. In particular, we consider minimum expected traveling distance of the team and reduce congestions. A Petri net (PN) with outputs models the movement capabilities of the team and the regions of interest. The imposed specification is translated to a set of linear restrictions for some binary variables, the robot movement capabilities are formulated as linear constraints on PN markings, and the evaluations of the binary variables are linked with PN markings via linear inequalities. This allows us to solve an integer linear programming problem whose solution yields robotic trajectories satisfying the task

Bridgeview(TM) for Hybrid Control System: an Applied Case Study of Automating an Industrial Assembly Line

Advancement in computer, sensors and controllers technology requires control engineers to deal with larger and more complicated controI system. It i no longer suficient to choose between a discrete or analog system because both types are often needed in today's sophisticated systems. A discrete and analog control systems are both extending rapidly to accommodate crucial properties of each other, the line of demarcation between them is becoming fuzzy. A new type of control system - Hybrid Control System (H S) - is emerging that combines the benefits of both. HCS's synergistic effect creates a control system that encompasses the features and functionality of each type and beyond. This work describes a case study of such a system. It involves design and implementation of supervisory software for a propriety Hybrid control system project involving a robotic assembly line for a cellular relay-station motherboard manufacturer. The scope of the project included system analysis of the robotic assembly line, selection of networking and communication protocols, database selection, and the design of an intuitive GUI or Man Machine Interface (MMI). Commercially available supervisory Control and Data Acquisition (SCADA) packages were reviewed to select a suitable environment. The software implementation on one station of the line is shown aa an example

Design and Simulation of a Supervisory Control System for Hybrid Manufacturing

The research teams of Dr. Bill Hamel, Dr. Bradley Jared and Dr. Tony Schmitz were tasked by the Office of Naval Research to create a hybrid manufacturing process for a reduced scale model of a naval ship propeller. The base structure of the propeller is created using Wire Arc Additive Manufacturing (WAAM), which is then scanned to compare created geometry to desired geometry. The propeller is then machined down to match the desired geometry. This process is iterated upon until the final product meets design tolerances. Due to the complex nature and numerous industrial machines used in the process, it is desirable to create a control system for Supervisory Control and Data Acquisition (SCADA). This supervisory control system is necessary in order to ensure safe operations and logging of system data to document successful trials. The goal of this thesis is to outline the design and simulation of a supervisory control system for this hybrid manufacturing cell. The design and implementation is focused on a simulation of the control of relevant boolean states of the system. This is accomplished through a Human Machine Interface (HMI) created in LabVIEW accompanied by appropriate data flow diagrams, models and communication specifications between machines. The creation of a digital twin of this hybrid manufacturing system was successful and useful in the implementation of physical components

Technology assessment of advanced automation for space missions

Six general classes of technology requirements derived during the mission definition phase of the study were identified as having maximum importance and urgency, including autonomous world model based information systems, learning and hypothesis formation, natural language and other man-machine communication, space manufacturing, teleoperators and robot systems, and computer science and technology

An annotated bibligraphy of multisensor integration

technical reportIn this paper we give an annotated bibliography of the multisensor integration literature