Supervisor for toner error handling : a case study in supervisory control of Océ printers

The purpose of this report is to demonstrate the viability of supervisory control synthesis approach by presenting the formulation and a preliminary solution of a real-life control problem in Oce printers. In a nutshell, supervisory control synthesis is a procedure for automatic generation of control algorithms based on the formal model of the underlying system (plant) and of the requirements the controlled system has to satisfy. The underlying theory guarantees that the generated control algorithm will indeed force the system to meet the specified requirements, provided that the model of the system and of the requirements are accurate enough. The viability of the approach is demonstrated by applying it to a particular use-case of Oce, the toner error-handling problem. The presence of continuous-time behavior in the current use-case compelled us to use supervisory control theory in a novel way. Usually, when applying supervisory control theory, the plant is modeled as an automaton and this automaton is constructed manually. Instead, here we generate the finite-state automaton model by a computer program, which takes as inputs the value of a number of physical parameters.The reason for choosing to generate the model by a program is that the model is obtained by discretizing a hybrid model in time. In turn, the time-step used in the discretization of the hybrid model is one of the parameters of the computer program. By generating the model automatically, we are able to experiment with supervisors for different discretization time steps and different values of physical parameters.