Research

Rock printing based on granular jamming

The optimal control problems of the nonlinear system were transformed into the iteration form of linear Hamilton system's two-point boundary value problems.

With the variational principle and the generating function, the receding horizon control problem was transformed into a set of sparse symmetric positive definite linear equations.

Based on the parametric variational principle the LQ optimal control problem with control inequality constraints was transformed into the Hamiltonian canonical equations coupled with the linear complementarity equation.

Designed a closed-loop controller by a rapid re-computation of the open-loop optimal control at each update instant.
Discussed the application of the closed-loop control in various fields like the spacecraft rendezvous problem between Halo orbits and the deployment and retrieval process of the Tethered Satellite System, etc.

Present a nonlinear closed-loop feedback control strategy for the spacecraft rendezvous problem with finite low-thrust between libration orbits in the Sun-Earth system.
Discussed the influence from the presence of the gravitational forces from the Moon, the navigational error and the actuator saturation limits as well.
Demonstrated the robustness, high precision and dominant real-time merits
of the proposed controller through several case studies.