11R8. Underwater Robots: Motion and Force Control of Vehicle-Manipulator Systems. Springer Tracts in Advanced Robotics, Vol 2. - G Antonelli (Dipartimento di Automazione, Elettromagnetismo, Ingegneria dell’Informazione e Matematica Industriale, Univ degli Studi di Cassino, Via di Biasio 43, Cassino, 03043, Italy). Springer-Verlag, Berlin. 2003. 183 pp. ISBN 3-540-00054-2. $89.95.
Reviewed by M Pascal (LSC, Univ d’Evry Val d’Essonne, 40 rue du Pelvoux, 91020 Evry, France).
The book originates from a PhD thesis defended by the author in 1999 at Naples University and is concerned by a new advance in robotics related to underwater vehicle-manipulator systems (UVMS). Several interesting applications of these systems can be found in industry and several models of autonomous underwater vehicles (AUV) are developed in various research centers. The design of control laws for underwater robots is a challenging task, owing to the complexity of the system and to the uncertainty in the model parameters, mainly due to the poor knowledge of the hydrodynamic effects. The implementation of standard control algorithms used for ground fixed manipulators is not easy and a necessary improvement of these control laws must be achieved to overcome all the drastic constraints of such systems.
The book involves four chapters followed by two appendices and a wide list of references. A great number of figures of good quality are also included. Chapter 1 is devoted to mechanical modeling of underwater robots composed of a rigid body connected to a serial manipulator. Rigid body’s kinematics is recalled, with a special attention to attitude representation by quaternions. Standard models of hydrodynamic effects are briefly presented, and the kinematics of manipulators with mobile base is described by Denavit-Hartenberg method. The dynamical model of the system is expressed in matrix form and its linear dependence with respect to a set of dynamical parameters is underlined. At last, a simplified model of the reaction force applied to the effectors in the occurrence of contacts with the environment is presented.
Chapter 2 deals with inverse kinematic resolution and kinematic control. An underwater vehicle-manipulator system is always redundant due to its mobile base. This redundancy is used in order to achieve both end effectors tracking trajectory and some other control objectives like avoiding singular configurations of the manipulator or energy savings. Several strategies of kinematic control are presented with special attention to the task priority approach and to an interesting application of fuzzy technique. These methods are applied on two models of UVMS and the corresponding numerical simulations seem to give promising results.
In Chapter 3, the dynamic control of UVMS is investigated. The sliding mode control is first proposed and validated by numerical simulation on a special model with eight degrees of freedom. Several other methods are also presented and simulated, including adaptative control, output feedback control, and virtual decomposition based control. At the end of the chapter, experimental results are shown: these results originate from a set of experiments performed at the University of Hawaii on a special model of AUV developed in this institute. Tracking trajectory is investigated by using several kinds of adaptative controls. The performances of these control laws are compared in the presence of disturbances such as current effects, thrusters’ fault, and strong noise of the sensors measures. A new adaptative control is also proposed, based on dynamical compensation expressed in a reference frame with respect to which the disturbance is constant, and experiments performed with this method give rather good results.
The last chapter introduces interaction control. A force control scheme without exact dynamical compensation is defined; the redundancy of the system is used to define a task priority inverse kinematics algorithm and suitable secondary tasks. Interesting numerical simulations are performed on a nine degree of freedom UVMS, showing the method’s efficiency.
In conclusion, Underwater Robots: Motion and Force Control of Vehicle Manipulator Systems provides an interesting reference text about control of underwater robots. The monograph can be useful for researchers interested by this field or, more widely, for scientists involved in control of manipulators with mobile bases or mobile robots in three-dimensional space.