## 1 Introduction  
As an ocean mobile observation platform, Wave Glider has been widely used in marine resources development, maritime exploration and military fields [1; 2; 3].  
Many researchers studied the equipment from different aspects. On design and optimization of Wave Glider, [PERSON] et al. [4; 5] conducted a preliminary study of whole performance of the Wave Glider, provided the design basis for the length and width of the glider and the length of the connecting cable, and realize the modeling and analyzing of Wave Glider by using the co-simulation of ADAMS and MATLAB software; [PERSON] et al. [6] proposed an optimization method based on the Latin HypercubeSampling (LHS) method and Computational Fluid Dynamics (CFD) method for the submersible propeller which is Blended Wing Body (BWB) layout, and obtained an optimization model for the BWB Water Glider; [PERSON] et al. [7] introduced the flexible webbed wings based on the researches of traditional Wave Glider, conducted an intensive study on the propulsion principle of the Wave Glider with webbed wings (WGWW), established a driving force calculation model of the flexible webbed wing and realized the glide function of the WGWW; [PERSON] et al. [8] designed and analyzed a recovery system to improve Wave Glider, the proposed solution was demonstrated to be feasible and met all design requirements, with an emphasis on simplicity.  
In order to study the kinematic performance of the Wave Glider, [PERSON] et al. [9], using computational fluid dynamics (CFD) to predict calm water resistance and seakeeping for the floating hull of Wave Glider, and concluded that the NPL hull is the optimum hull compared to the other hulls; [PERSON] et al. [10] determined the kinematics model for the Wave Glider platform developed by Liquid Robotics and estimated the speed and environmental parameters for a desired heading; [PERSON] et al. [11] applied Gaussian process models to existing wave model data to predict the performance, and carried out an effective method for forecasting WG velocity; [PERSON] [12] analyzed the motion of a Wave Glider and studied its forward speed at different sea states based on CFD numerical simulation technology.  
For determining the effect of the connection cable on the performance of Wave Glider, [PERSON] et al. [13] established a dynamic model of the Wave Glider by using the Kane method, and analyzed the effect of sea states and cable lengths on the propulsion performance. [PERSON] et al. [14] discretized the cable that connected the surface vessel and the submersible propeller into several small segments for analysis, and obtained the motion equations between the surface vessel and the submersible propeller, and found that the speed of the Wave Glider is easy to adjust as the wave changes due to the effect of the flexible cable, in addition, the short cable is in favor of motion transmission. Liquid Robotics proposed two kinds of design, one is a rigid hinged rod consisting of two hinged rigid rods, which can improve operability for deployment and recycling of the Wave Glider, another has two independent rigid rods, which is applied to reduce the possibility of cable twisting [15].  
The connection structure is an important component for the safety and reliability of the Wave Glider. It is essential to study the effects of the connection types on the performance of the Wave Glider. In this paper, the relationship between connection structure and the performance of the Wave Glider is studied. Several connection types such as rigid rod, cable, multi-link and elastic rod are considered to connect the surface vessel and the submersible propeller. Considering the connection characteristics, the integrated dynamic models are established by applying multi-body dynamics software ADAMS with consideration of the hydrodynamic forces on different components of Wave Glider, and the horizontal displacement and velocity of the surface vessel and the tension forces on the connection structure with different types have been compared.