Formal synthesis of supervisory control software for multiple robot systems

Abstract

This paper demonstrates the application of a range of theoretical tools to generate real-time control software for multiple ground robots working together cooperatively. Specifically, existing discrete event system theory is applied to synthesize high-level supervisory control logic that is guaranteed to maintain the behavior of multiple robots within requirements defined by a set of formal specifications. The modeling of the high-level behavior of the robots in their given environment, as well as the formal specifications, is described in detail. The resulting models are represented as finite-state automata. In this work we assume that some events cannot be controlled, though all events are assumed to be observable. In addition to generating control logic that is guaranteed to keep the robots safe, results are also presented for choosing from amongst a set of allowed robot behaviors in order to achieve behavior that is "good" in some sense. Specifically, a modified version of Dijkstra's algorithm is employed to choose a path through the finite-state automaton representing the allowed robot behaviors. This modified algorithm is able to address multiple robots and the fact that some events cannot be controlled (commanded). The resulting high-level robot events are then connected to the continuous, time-driven behavior of the robots through a series of low-level algorithms. The result of this work is demonstrated in simulation for a simple, but demonstrative scenario.

Controlling Supervised Industry 4.0 Processes through Logic Rules and Tensor Deformation Functions

“…Logic rules have been also employed to implement robot navigation frameworks (Kloetzer and Mahulea, 2016) and different mechanisms to optimal (Fabre and Jezequel, 2009) or clean paths (Iqbal et al, 2012) in robotized Industry 4.0 have been also reported. Works on this area are also evaluating, in a formal way, the scalability (Hill and Lafortune, 2017) and software characteristics (Goryca and Hill, 2013) of supervisory software solution for Industry 4.0.…”

Robot Planning Based on Boolean Specifications Using Petri Net Models

“…Recently, abstractions characteristic to Resource Allocation Systems were used based on finite automata [24], [25], [26], [27] or PNs [28], [29], [30], while methods available for deadlock avoidance have been adapted for enforcing the reachability of desired final states. In this paper we are interested in computing robot trajectories to accomplish Boolean based specifications for the robots by using the PN models, while the collision avoidance is partially solved.…”

Towards decentralized and parameterized supervisor synthesis

“…We have brought up a new idea for obtaining a language-theoretic characterization of the solvability of the decentralized realization problem. From the obtained characterization result, the close relationship among the decentralized realization, supervisor decomposition and language decomposition problems becomes immediately clear (see pages 26,27,28). It is then straightforward to obtain complexity-theoretic lower bound proofs for the supervisor decomposition problem and the decentralized realization problem, by reductions from the language decomposition problem.…”

“…The theory of supervisory control of discrete-event systems was originally initiated in the 1980s by Ramadge and Wonham [14], [15], [16], [17] and has been under active development for more than 30 years (see the textbooks and monographs [13], [18], [19]). The main domains of applications for supervisory control theory are the coordination of complex man-made systems such as manufacturing systems [13], [20], [21], telecommunication and network protocols [22], [23], database management sytems [24] and transportation [13], [25], e.t.c., where coordination and conflict resolution [26], [27], [28] are usually needed to ensure certain safety and liveness properties. A brief list of some of the more important developments and those developments that are more closely related to ours is provided below.…”