The limb-driving force mutation of the modular combination parallel manipulator (MCPM) affects the alignment process of optical axis. In this paper, a novel optimization method based on the force mutation penalty term is proposed to solve the problem of driving force mutation. The kinematics and dynamics models of the manipulator are established using a modularization idea, reducing the complexity of the modeling process, and verified using co-simulation. Moreover, particle swarm optimization (PSO) is applied as an optimization tool. The effectiveness of the proposed method is confirmed by comparing it with the minimize-the-maximum and Moore–Penrose (M–P) methods, which are widely used to solve parallel manipulators with redundant drives.

This paper presents a virtual dynamic vibration absorber (DVA) trap fusion active vibration suppression algorithm based on inertial actuators as a solution to the harmonic vibration control problem of large flexible space trusses. Firstly, the mechanism of the inertial actuator is analyzed, and the relationship between the bandwidth of the algorithm and the intrinsic frequency of the inertial actuator is derived. Secondly, a dynamic model of the space truss is constructed. Subsequently, an analysis is conducted to determine the manner in which the virtual DVA exerts influence on the system’s dynamic characteristics. Based on this analysis, a virtual DVA trap fusion active vibration suppression algorithm is designed. Finally, the efficacy of the proposed algorithm in suppressing vibration is demonstrated through experimentation. The algorithm was demonstrated to be effective in suppressing both single-frequency harmonic vibration and multi-frequency harmonic vibration under the working conditions of single-degree-of-freedom and multi-degree-of-freedom of a flexible truss. The vibration suppression efficiency was found to be greater than 60%. It is therefore evident that the proposed algorithm has the potential to be applied to the vibration suppression of telescopes assembled in orbit in the future.

To improve the optical concentrator ratio of space solar power stations (SSPSs), this paper proposes a deployable segmented solar concentrator (DSSC) based on an afocal reflective system. First, a novel concept of an afocal reflective concentrator composed of segmented primary and secondary mirrors is introduced, and the deployable mechanism for the segmented primary mirror is described in detail. Subsequently, a model for the comprehensive error of the deployable mechanism with 3D revolute joint clearances and link length errors is established based on the “massless link” equivalent model of the clearance in revolute joints and the homogeneous transfer matrix. Sensitivity analysis evaluates the impact of various geometric errors of the deployable mechanism on the comprehensive error. Finally, a prototype experimental system is built to verify the concentration ratio of the concentrator and the pose error of the deployable mechanism. The experimental results show that the DSSC geometric concentration ratio reaches 5.36 to 6, and the optical concentration ratio reaches 24.7 to 32.2. The repeatability of the deployable mechanism is ±50 µm and ±1.2′, meeting the tolerance requirements of the optical system. The proposed afocal reflective DSSC can be used for solar energy concentration, improving the utilization of solar energy.

Extreme ultraviolet (EUV) thin-film filters are key optical components in space-based EUV imaging, employed to reject out-of-band visible and ultraviolet radiation. Currently, aluminum (Al) and zirconium (Zr) EUV filters are predominantly used due to their superior mechanical strength and stability. In contrast, indium (In) EUV filters had not been successfully deployed in spaceborne EUV cameras prior to this work. Their inherent fragility makes them highly susceptible to vibration and acoustic loads during the launch phase, ultimately resulting in structural failure. This study presents a comprehensive investigation into the structural protection strategies for indium EUV filters in space applications. Through systematic analysis of the photoenergy requirements and the mechanical characteristics of the indium filters, a robust filter assembly was developed, and vibration isolation as well as acoustic mitigation designs were implemented for the assembly. Finite element simulations and environmental tests confirmed that the indium filters can withstand vibration and acoustic loads. This technology has been successfully implemented in the 83.4 nm channel of the Extreme Ultraviolet Camera (EUVC) onboard the Queqiao-2 relay satellite for the Chang’E-7 mission. Subsequent in-orbit tests validated the structural integrity of the indium filters, providing a valuable technical reference for their successful application in future spaceborne EUV cameras.