Wei Wang

• Doctor of Philosophy
• Professor (Associate) at Shanghai Jiao Tong University

The aim of this Note is to establish a methodology for generating displaced orbits around L2 point in the Earth-Moon ER3BP using a hybrid sail. In particular, the problem of displaced orbits design is formulated using the linearized dynamics of a solar sail, whereas the auxiliary SEP system is for orbital stabilization. The hybrid propulsion system...

In this paper, the fuel-optimal control problem of multiple spacecraft formation flying with relative motion constaints is addressed via the indirect optimization method. As opposed to the most existing works where the formation deployment/reconfiguration problem is formulated on the chief-deputy topology or the total fuel consumption is optimized...

In this paper, a spacecraft formation control framework is presented aimed at guaranteeing a long-term bounded relative motion in the asteroid's uncertain dynamical environment. The mean-orbital-elements-based invariant boundedness conditions via an approximate gravitational field are adopted to develop a nominal steering control strategy, while a...

Micrometre level ranging accuracy between satellites on-orbit relies on the high-precision calibration of the antenna phase center (APC), which is accomplished through properly designed calibration maneuvers batch estimation algorithms currently. However, the unmodeled perturbations of the space dynamic and sensor-induced uncertainty complicated th...

In spacecraft formation flying missions, the projected circular (relative) orbit (PCO) which appears circular when viewed along the zenith-nadir direction of the nominal chief spacecraft, is suitable for constructing a synthetic aperture radar. In this paper, the analysis of a PCO for spacecraft formation flying near a slowly rotating asteroid is c...

In this paper, the closed-form along-track boundedness condition for spacecraft relative motion around a slowly rotating asteroid is presented. As opposed to the previously proposed criteria where three necessary constraints must be satisfied, the current approach only requires to enforce one constraint to suppress the along-track drift, thus allow...

Traditionally, indirect methods for trajectory optimization start with the non-intuitive guesses of the initial costates, but it is difficult to generate the initial guesses for the low-thrust many-revolution problems. In this paper, a new indirect method with analytical initialization of the costates has been developed for obtaining the minimum-ti...

The aim of this paper is to propose a distributed control architecture for a solar sail-based formation, flying around an L2-type artificial equilibrium point in the Sun-[Earth + Moon] circular restricted three-body problem. Two typical cases, depending on whether the formation structure is leaderless or includes a virtual leader, are investigated....

Purpose The purpose of this paper is to obtain the reachable domain (RD) for spacecraft with a single normal impulse while considering both time and impulse constraints. Design/methodology/approach The problem of RD is addressed in an analytical approach by analyzing for either the initial maneuver point or the impulse magnitude being arbitrary. T...

This paper investigates the problem of multiple solar sail-based spacecraft formation flying in which the chief follows a heliocentric displaced orbit, whereas each deputy adjusts the sail propulsive acceleration so as to track a desired (relative) trajectory with respect to the chief. In particular, coordinated control strategies are presented for...

This paper presents a distributed adaptive control framework for multiple spacecraft formation flying around Lagrange point orbits, which account for unmeasurable velocities and (spacecraft) mass uncertainties. The nominal trajectory for the formation system is a halo orbit parameterized by Fourier series expansions. Such an explicit, albeit approx...

We analyze a cooperative control framework for electric sail formation flying around a heliocentric displaced orbit, aiming at observing the polar region of a celestial body. The chief spacecraft is assumed to move along an elliptic displaced orbit, while each deputy spacecraft adjusts its thrust vector (that is, both its sail attitude and characte...

We present a geometrical methodology for analyzing the formation flying of electric solar wind sail based spacecraft that operate in heliocentric, elliptic, displaced orbits. The spacecraft orbit is maintained by adjusting its propulsive acceleration modulus, whose value is estimated using a thrust model that takes into account a variation of the p...

This paper discusses a methodology for modeling the relative motion between heliocentric displaced orbits by using the Cartesian state variables in combination with a set of displaced orbital elements. Similar to classical Keplerian orbital elements, the newly defined set of displaced orbital elements has a clear physical meaning and provides an al...

This paper provides a framework to obtain a semi-analytical approximation of extreme values of relative distances between two spacecraft that cover elliptic displaced orbits. The relative motion is described in the rotating reference frame of the chief spacecraft and is parameterized with a new set of displaced orbital elements. The extreme values...

The optimal single-impulse maneuver for spacecraft cluster flight is studied in this paper. Based on Gauss' variational equations, the optimal conditions and solutions for time-fixed and time-unfixed case are provided via the periodic condition of nonlinear relative motion. For the time-fixed case, the problem is also treated from the perspective o...