Research On UUV Typical Mission Simultaneous Demonstration And Posture Predicting Technic

The UUV(Unmanned Underwater Vehicles) system is a complicated autonomous control system which is difficult for man-in-the-loop. It's very important for improving its safety and reliability to complete the voyage demonstration of the UUV system. The UUV mission simultaneous demonstration can simulate the process of UUV mission control and task perform, it provides a suppositional auxiliary monitoring platform for test personnel to make commands and decisions. In this paper, we will give a fully study of the simultaneous demonstration and posture predicting (SDAPP) technology for an observation UUV's typical mission, the correlative technologies and key problems are studied as follows.Firstly, according to the characteristics of UUV communication and monitoring system,the mission directed platform frame structure for UUV simultaneous demonstration was proposed. With respect to the real-time simulation, a detailed analysis of the anticipant functional and design requirements of the UUV mission rehearsal system was implemented,and the entity models including the vehicle and the background environment involved in the mission rehearsal process were modeled. Based on the software and hardware as well as the UUV control system, the model aid posture predicting scheme was established.Secondly, to approximate the UUV dynamic identities by test data, the equivalent UUV"black box" model was proposed. In order to improve the UUV black-box model identification accuracy, an improved Elman neural network structure based on output feedback method was adopted, which made the output of the network as the input associated with the hidden layer after delay feedback, and the weights of the hidden layer to output layer were on-line adjusted by least squares method. The training samples of NN were measured data which came from a Lake trial, to evaluate the reliability of the NN, the confidence interval analysis method was utilized, and results show that the UUV black-box model had stronger generalization ability.Thirdly, in view of the external interference problems such as current and so on during the process of the vehicle's operation, to achieve better simulation performance which is more close to the ture ue UUV, a posture correction method was proposed with the current disturbance.The cubic spline interpolation function was utilized to fitting the current data in a tidal table,and the resulting current velocity and current direction data was compensated to the UUV black-box output speed and heading respectively. As a result, the reliability of the proposed SDAPP method was further more improved.Finally, combining the observation mission directed UUV in this paper, three typical mission routes were designed to carry out the SDAPP simulation, which commonly used in sea trials. That are, the "bathtub curve" to detect sea water by a CTD detector, the "lawn mower" route for side scan sonar to detect ocean floor,and the "eight shape" route for endurance test. The SDAPP method was verified through simulation and replaying method using experiment data from sea trial, results show that the proposed method can realize a simultaneous simulation to the true UUV's sailing and achieve real-time prediction for its posture.The results of this study show that, the simultaneous demonstration platform had well demonstration performance and higher accuracy for simulating the true UUV's operation by identifying the UUV black-box model and compensating current. It achieved the functions including preview and simultaneous demonstration and so on, providing a strong technical support for improving the safety and reliability of UUV system consequently.