Authors:
            
                    Jurek Czyzowicz
                    
                        
                                1
                            
                    
                    ; 
                
                    Konstantinos Georgiou
                    
                        
                                2
                            
                    
                    ; 
                
                    Evangelos Kranakis
                    
                        
                                3
                            
                    
                    ; 
                
                    Fraser MacQuarrie
                    
                        
                                3
                            
                    
                     and
                
                    Dominik Pajak
                    
                        
                                4
                            
                    
                    
                
        
        
            Affiliations:
            
                    
                        
                                1
                            
                    
                    Universite du Quebec en Outaouais, Canada
                
                    ; 
                
                    
                        
                                2
                            
                    
                    Ryerson University, Canada
                
                    ; 
                
                    
                        
                                3
                            
                    
                    Carleton University, Canada
                
                    ; 
                
                    
                        
                                4
                            
                    
                    Wroclaw University of Technology, Poland
                
        
        
        
        
        
             Keyword(s):
            Idleness, Mobile Robots, Patrolling, Speed, Walking, Scheduling.
        
        
            
                Related
                    Ontology
                    Subjects/Areas/Topics:
                
                        Applications
                    ; 
                        Artificial Intelligence
                    ; 
                        Knowledge Discovery and Information Retrieval
                    ; 
                        Knowledge-Based Systems
                    ; 
                        Methodologies and Technologies
                    ; 
                        Operational Research
                    ; 
                        Optimization
                    ; 
                        Pattern Recognition
                    ; 
                        Scheduling
                    ; 
                        Software Engineering
                    ; 
                        Symbolic Systems
                    
            
        
        
            
                Abstract: 
                A fence is to be patrolled collectively by n robots. At any moment a robot may move in one of the two possible states: walking or patrolling. Each state is associated with a maximal moving speed which cannot be exceeded. We want to schedule the perpetual movements of the robots so as to minimize the idleness, defined as the smallest time interval within which every point is always visited by some robot. First, we give a centralized algorithm constructing schedules with optimal idleness, and subsequently we show an interesting application to a transportation problem concerning Scheduling with Regular Delivery. Our main contribution is the study of distributed, dynamical schedules for patrolling robots with only primitive capabilities. Surprisingly, we are able to design a dynamic schedule for very weak collections of two robots (silent, oblivious, passively mobile), achieving the optimal idleness. Part of our contribution is a very technical analysis of the dynamics of special familie
                s of dynamical systems of n robots that we call regular. For such systems we also propose a highly non-trivial O(n2) algorithm to decide whether or not robots converge to a stable configuration thus verifying if the dynamic schedule is optimal.
                (More)