Authors:
            
                    Aron Pujana-Arrese
                    
                        
                    
                    ; 
                
                    Kepa Bastegieta
                    
                        
                    
                    ; 
                
                    Anjel Mendizabal
                    
                        
                    
                    ; 
                
                    Ramon Prestamero
                    
                        
                    
                     and
                
                    Joseba Landaluze
                    
                        
                    
                    
                
        
        
            Affiliation:
            
                    
                        
                    
                    IKERLAN Research Centre, Spain
                
        
        
        
        
        
             Keyword(s):
            Pneumatic muscle, Robotic Arm, Position/Force Control, Hybrid Control, Impedance control.
        
        
            
                Related
                    Ontology
                    Subjects/Areas/Topics:
                
                        Informatics in Control, Automation and Robotics
                    ; 
                        Intelligent Control Systems and Optimization
                    ; 
                        Mechatronic Systems
                    ; 
                        Robot Design, Development and Control
                    ; 
                        Robotics and Automation
                    
            
        
        
            
                Abstract: 
                A one-degree-of-freedom set-up driven by pneumatic muscles was designed and built in order to research the applicability of pneumatic artificial muscles in industrial applications, especially in wearable robots such as exoskeletons. The experimental set-up is very non-linear and very difficult to control properly. This paper describes the control of this mechatronic system’s interaction with its environment, controlling both its position and the force exerted against it. The classic position/force control techniques - hybrid control and impedance control - have been adapted to pneumatic muscles and applied to the experimental set-up developed. An alternative solution is also proposed whereby force or torque control is based on the calculation made by an estimator instead of on direct measurement by a sensor. The article presents a detailed analysis of the force and torque estimator used to close the control loops in the two position/force control schemes. Finally, the article conclud
                es by presenting the experimental results obtained and the most outstanding conclusions of the study as a whole. 
                (More)