Ph.D. received on: 17/4/1998

E-mail: davsi@dist.unige.it

Tutor: Prof. G. Casalino, University of Genova
 
 

 ___________________________________________________________________________________________________________

Algorithms, techniques and tools for telerobotics   ___________________________________________________________________________________________________________

Advisor:

Prof. G. Casalino, University of Genova
 

Summary:

Main goal of modern industrial robotic is to free mankind from performing heavy and boring tasks. Telerobotics is the discipline which allows to execute manipulative operations remotely. This aim is achieved feeding commands to a remote manipulator by means of a local interface which interacts with the human operator. Hence telerobotics is going to substitute, in perspective, people with mechanical arms and vehicles also during task execution in hazardous or hostile environments. It has also the goal of substituting  mankind during the execution of task involving high costs due to the fact that the site is unreachable or reachable with difficulties. This refers in particular to space and underwater applications. It has been very relevant from an industrial point of view the telerobotic application to the ultrasonic based non destructive inspection techniques of in-service plants like nuclear power plants, off-shore platforms, etc..
This Phd thesis has been developed within a joint research programme between the DIST (Department of Telecommunications, Systems and Computer Sciences) and Ansaldo Nuclear Division. My research aim was the analysis of algorithms, techniques and tools applied to the control of robotics systems. Such systems have to be used for an automated, remote and smart inspection of welded seams within nuclear plants, using ultrasonic based approaches.
During my thesis two different methodologies of remote control have been defined, implemented and tested. The testing phase regarded both the theoretical and the experimental aspects of the research. First approach is of master-slave type with a shared continuos control of the contact force. The second is of supervisory and autonomous type with hybrid position-force control. From the controller point of view the system core is just the hybrid position-force regulation. A stability and robustness proof is given in the thesis about the proposed controller.
This thesis tackles also the problem of the design of hardware and software architectures for the real-time multiprocessor control of dynamic systems. A number of development tools have been carried out, allowing a novel approach to the design of control schemes in a fast way. Such methodology uses a simple and user-friendly graphical interface. The tools, jointly with the control algorithms described above, have led to the definition of an ‘Open’ controller with characteristics of modularity, scalability and reusability.
 

 _______________________________________