This paper investigates a novel leader-following attitude control approach for spacecraft formation under the preassigned two-layer performance with consideration of unknown inertial parameters, external disturbance torque, and unmodeled uncertainty. First, two-layer prescribed performance is preselected for both the attitude angular and angular velocity tracking errors. Subsequently, a distributed two-layer performance controller is devised, which can guarantee that all the involved closed-loop signals are uniformly ultimately bounded. In order to tackle the defect of statically two-layer performance controller, learning-based control strategy is introduced to serve as an adaptive supplementary controller based on adaptive dynamic programming technique. This enhances the adaptiveness of the statically two-layer performance controller with respect to unexpected uncertainty dramatically, without any prior knowledge of the inertial information. Furthermore, by employing the robustly positively invariant theory, the input-to-state stability is rigorously proven under the designed learning-based distributed controller. Finally, two groups of simulation examples are organized to validate the feasibility and effectiveness of the proposed distributed control approach.

In this brief, a novel leader‐following appointed‐time consensus control protocol is investigated for second‐order multi‐agent systems on a directed graph from the prescribed performance perspective. Through developing a new state‐independent performance function, the practically fixed‐time stability or expected appointed‐time tracking accuracy of the leader‐following network systems can be achieved, wherein, the state‐independent setting time can be arbitrarily specified a priori. Compared with the existing works, the primary advantage of the proposed control protocol is that no fractional power state feedback is used and the transient behaviours including the appointed‐time convergence rate, overshoot and undershoot can be synthesised simultaneously. Moreover, the excellent disturbance suppression capacity can be achieved just through adjusting a few parameters involved in the newly developed performance controller. Finally, two groups of illustrative examples are employed to validate the effectiveness of the proposed control protocol.

This paper investigates an adaptive model-free constrained prescribed performance control approach for flexible spacecraft with an unknown captured object subject to unknown inertial properties, elastic vibration, actuator saturation, and external disturbance. First, the attitude kinematics and dynamics of the postcapture flexible spacecraft are transformed into a Euler–Lagrange form, based on which a model-free constrained attitude prescribed performance controller comprising a nominal control term and an adaptive compensation control term is developed. Then, by employing norm equalities of the Euler–Lagrange systems, a model-free adaptive scheme is designed to improve the robustness with respect to uncertainty, actuator saturation, and external disturbance just only using the state information. Compared with the existing works, the primary advantage is that the resultant controller and adaptive scheme are computationally very simple without any requirement of unknown inertial information. But the transient and steady-state performance is a priori guaranteed without resorting to repeated regulations of the controller parameters. Finally, the application to attitude stabilization and tracking of postcapture flexible spacecraft along with active vibration suppression is employed to validate the effectiveness of the proposed approach.