Showing papers by "Jianjun Luo published in 2021"
01 Apr 2021
TL;DR: A survey for the prescribed performance control methodology is constructed along with the detailed analysis of the attitude control methods in the existing reported works, and potential open issues of the prescribedperformance control methodology are analyzed.
Abstract: High-quality control method is of great importance for the attitude determination and maneuvering of spacecraft in the on-orbit servicing technology. Prescribed performance control methodology, as ...
37 citations
TL;DR: In this paper, global manipulability based on capability map is applied as the quality index to seek optimal grasping poses for dual-arm space robot cooperatively grasping an uncooperative satellite.
11 citations
TL;DR: A time-optimal control problem (OCP) that considers target attitude motion bounds as well as interaction torque limits at the grasping point is formulated and can be solved using the Calculus of Variations method with a highly accurate solution.
9 citations
TL;DR: The dynamic manipulability factor and dynamic manipulation ellipsoid are proposed as two tools for the dynamic manipULability measure, where the effects of the bias acceleration are considered.
Abstract: The dynamic manipulability of a manipulator refers to the capacity to generate accelerations given the joint torques, which is an important indicator for motion planning and control. In this paper, the dynamic manipulability analysis is extended to the multi-arm space robot, and further to the closed-loop system composed of the space robot and the captured target. According to the dynamic equations, the relation between the joint torques and the end-effector accelerations in the open-loop space robot and that between the joint torques and the target accelerations in the closed-loop system are derived. On this basis, the dynamic manipulability factor and dynamic manipulability ellipsoid are proposed as two tools for the dynamic manipulability measure, where the effects of the bias acceleration are considered. The influences of dynamic parameters, link lengths, joint variables, and velocities on the dynamic manipulability measure are mainly studied.
7 citations
01 Jun 2021
TL;DR: An adaptive compliant stabilization control scheme is proposed for a safe and reliable stabilization process that can be controlled and the target can be stabilized under the influence of the measurement noise in the contact wrenches.
Abstract: Safety and reliability are the primary prerequisites of space robotic manipulation. Due to the inaccurate inertial parameters of the tumbling target, tracking the desired trajectory directly will l...
5 citations
TL;DR: In this article, a time-varying state transition matrix of Tschauner-Hempel equations is designed by learning an analytical solution of the true anomaly using machine learning techniques.
2 citations
01 Feb 2021
TL;DR: In this article, the problem of autonomous rendezvous in the libration point orbit without relative velocity measurement information is studied. The proposed rendezvous algorithm consists of the finite-time finite-space rendezvous.
Abstract: This paper studies the problem of autonomous rendezvous in the libration point orbit without relative velocity measurement information. The proposed rendezvous algorithm consists of the finite-time...
1 citations
TL;DR: This paper develops a robust coordinated control mechanism for multiple modular robots when they cooperate to control the orbit and attitude movements of a substructure using a distributed information-based scheme for control allocation.
Abstract: On-orbit assembling technology provides a promising way for deploying large space systems. Transporting a substructure by adjusting its orbit and attitude states is a key to assembling it to the main body of a large space system. This paper develops a robust coordinated control mechanism for multiple modular robots when they cooperate to control the orbit and attitude movements of a substructure. By designing a distributed information-based scheme for control allocation, the modular robots are able to obtain their control inputs through their local interaction. The computation and communication burdens are therefore distributed among the modular robots. Nonlinear disturbance observers are introduced to suppress the adverse effects caused by external disturbances, parameters uncertainties and orbit-attitude coupling effect of the substructure. A new input saturation compensator is designed to suppress the effect caused by input saturation whenever the commanded control inputs of the modular robots exceed the permissible range. The stability of the closed-loop system is analyzed using the Lyapunov method, and the tuning conditions of the coordinated control mechanism are obtained. Numerical simulations demonstrate the effectiveness of the proposed method.