Distributed Containment Control For Multiple Ocean Bottom Flying Node Systems

In recent years,according to the current global situation,people focus more on exploitation of marine resources more than ever before,and relevant sciences and technologies have developed spontaneously.As an important underwater detection equipment,the research about AUV is an indispensable key link,which will provide richer and more accurate data for ocean scientific research.Compared with the single AUV,multiple AUVs for resource detection have significant advantages,such as stronger adaptability,greater flexibility,and lower operation and maintenance cost.By summarizing the research results of the existing cooperative control methods for multiple AUV systems,the distributed containment control strategies for multiple Ocean Bottom Flying Nodes(OBFN)systems is investigated deeply in this thesis.The main work are represented as follows.Based on directed commination topology,the problem of distributed finite-time fault-tolerant containment control for multiple OBFN systems in presence of model uncertainties,external disturbances,and thruster faults is investigated.By defining the containment error variables and using nonsingular fast terminal sliding technique,the nonsingular fast terminal sliding surface is chosen.Considering that setting the upper bound of disturbances is more conservative,neural network technique is used to estimate and the model uncertainties,thruster faults and ocean disturbances together.The upper bounds of estimation error is compensated by designing an adaptive law.Then a distributed finite-time containment control method is designed,so that the follower OBFNs could enter the convex hull formed by the leader OBFNs in finite time.Under the directed communication topology,the distributed finite-time fault-tolerant error constraint containment control problem for multiple OBFN systems is solved,while only a part of follower OBFNs can measure the state of leaders.The neural network technique is employed to mitigate the adverse effects of general disturbances.Based on the directed topology and back-stepping method,a distributed finite-time fault-tolerant containment control problem for multiple OBFNs with error constraint is proposed by using a tan-type Barrier Lyapunov Function.Thus the followers can track the leaders in a finite time and the tracking error always are always limited in the desired range during moving.The distributed finite-time fault-tolerant error constraint containment control problem considering input saturation for multiple OBFN systems is investigated.Through utilizing the hyperbolic tangent function as the input signal,the command filter is designed and the virtual velocity error command is generated to follow the velocity error.Then the novel velocity error constraint containment control algorithm is developed,as that the velocity error can approach the virtual velocity error in finite time.Furthermore,for the problem of input saturation,by combining the saturation model with the OBFN dynamic model and designing a stable anti-saturation compensator,an improved containment algorithm is proposed.And both of the proposed approaches can enable the followers to reach the convex hull consisted of leaders in finite time.