Research On Information System For Small AUV

With the increasingly profound "blue belief" of human beings and the accelerated pace of understanding of the ocean,the rapid development of underwater vehicle monitoring equipment has been promoted.As an important assistant of human underwater operations,underwater vehicles are constantly updating their functions and application fields,among which the small autonomous underwater vehicle(AUV)will become an important observation node in the future ocean observation network.It will become the main market demand in the popularity of underwater vehicles in the future.However,at present,there is no standardized product for the electronic system with a variety of information collection functions,and the low-cost information system has effective popularity to AUV,so this paper takes the small AUV information system as the research object,based on the principle of generality and expansibility,in order to provide standardized information system,relying on the information system design process to study information collection and integrated navigation.The design work of the information system completes the conceptual design by determining the design index,determines the information system architecture to complete the preliminary design,and completes the module design by determining the module division scheme carried out synchronously and crossover according to the two methods.The implementation of software and hardware and docking debugging are studied in detail.According to the basic information collection function,the mechanical information flow and vision,obstacle avoidance and chemical information flow of the information system are constructed according to the architecture,and the preliminary burnable program is completed according to the design way of process module.The quaternion method,directional cosine method and integration method are used to solve the attitude,position and velocity respectively,and the part of the mechanical information flow is arranged in detail.the error transfer relation of strapdown navigation system is given and the error equation is derived.Taking information as the idea,electronics as the tool,combined with the development direction of small AUV facing standardization,the design concept of "plug and play" is put forward.According to the method of dividing functional modules,the electronic system of the main control board is designed,and the hardware main control board with basic function interface and extended interface is completed.Based on the design index and the purpose of verifying the hardware main control board,the main hardware selection of low cost periphery is completed.The main control board is integrated with the hardware and docked with the program for preliminary debugging and use,and good results are obtained.Aiming at the main function navigation function of the information system,the SINS simulator is established according to the mechanical solution process.It is found that the navigation divergence is serious by using pure inertial sensor.Combined with the error transfer relation and error equation,the Kalman filter is introduced,and the SINS filter model is established to deal with the divergence effectively,but the accuracy still can not reach the design index,especially the vertical error is large.In order to solve the problem of low precision of low-cost navigation devices dominated by mechanical information,a tightly coupled distributed feedback correction filter scheme is selected according to the characteristics of the system,and a depth meter is introduced to correct the elevation by reducing the low frequency error through the second-order damping loop.The state quantity and observation are selected,the Kalman filter model of the integrated navigation system is established,and the simulation trajectory close to the reality is designed,and the simulation is carried out by using this model and trajectory data.After filtering,the standard deviation of ENU position and velocity error is reduced,the noise of navigation sub-module is compressed,especially the vertical error is stabilized,and the filtering effect is good.