This paper studied the dynamic characteristics of electrodynamic tethered satellite with consideration of coupled multiphysics field for orbital boost maneuver by a fully insulated electrodynamic tether (EDT). We proposed a simplified analytical nonlinear current–voltage circuit method based on the Parker–Murphy model to evaluate the real-time electric current-carrying tether. Furthermore, the performances of orbital boost maneuver by a fully insulated electrodynamic tether is investigated. This current–voltage model is influenced by the electron density, the intensity of Earth’s magnetic field and the space plasma temperature. The hollow plasma contactor located on the sub-satellite to attract the electrons from the ambient plasma. An on-board power supply is adopted to change the direction of electric current for boosting the system. The direction of electric current in tether is from main-satellite to sub-satellite. The efficiency of orbital boost maneuver is compared with different sizes of anodic contactors and the given voltage of power supply. The simulation results showed that electric current is easily affected by the fluctuation of electron density, the Earth’s magnetic field and plasma temperature. The electrodynamic tether system can stable boost its orbit altitude from 400 to 1200 km in four cases by a fully insulated electrodynamic tether.

Laminate composite components have been widely used in engineering fields, such as aerospace and aircraft fields, automotive industries, marine and civil engineering. Due to inherent properties of laminated composites, the effects of local delamination defects will result in a decrease of assembly dimensional precision and mechanical property, and a variation analysis considering the effect of delamination defects become increasingly indispensable. In order to understand the influence relationship between delamination defects and manufacturing deviations, a methodology based on the method of influence coefficients is proposed to analyze the influence relationship between delamination defects and manufacturing deviations. Then, local delamination modes are developed based on the interface deformable bi-layer beam model with consideration of transverse shear and delamination tip deformations. This model provides an accurate solution with the delaminated composite structures. Finally, the effect of local delamination length ratio (a/h) has been further studied for the assembly precision analysis based on the flexible joint model, and the comparison of simulation result shows that the delamination has a signification influence on the structural performance and the quality of the product.

This paper presents a nonlinear velocity observer of tether deployment using the immersion and invariance technique, and the velocity observer design problem is recast as a problem of designing an attractive and invariant manifold inside the Hamiltonian framework. The passivity-based control theory is used to define an expected Hamiltonian function, and the stability of the designed velocity observer is addressed by using the passivity-based methodology. Finally, a simple tension control law with measurable and unmeasurable states is employed for controlling the tether deployment, where the unmeasurable states use the proposed velocity observer. Numerical simulations demonstrate that the proposed velocity observer is working successfully. Sensitivity analyses are conducted to test the effectiveness and robustness of the proposed velocity observer.