Frequency Division Control of Line-of-Sight Tracking for Space Gravitational Wave Detector

Abstract

The space gravitational wave detector uses the inter-satellite laser interferometer to measure a change in distance with ultra-high precision at the picometer level. Its special differential wavefront sensing technology based on laser interference is used to obtain the ultra-high-precision relative attitude between spacecrafts. In order to acquire the measurement, it is necessary to maintain high-precision attitude pointing and alignment for the optical path line-of-sight of the detector. This paper proposes a frequency division control method. More specifically, we chose the telescope attitude control loop frequency division as it is the faster response part, mainly relative to the high-frequency band within the measurement bandwidth. The spacecraft attitude frequency division is mainly in the low-frequency band within the measurement bandwidth. Finally, a high-precision simulation analysis is carried out. The results show that compared with traditional methods, the use of frequency division control design can significantly improve the attitude and pointing stability of the system and provide control support for systems requiring high pointing coordination accuracy, such as space gravity wave detectors.

Research on High-Stability Composite Control Methods for Telescope Pointing Systems under Multiple Disturbances

“…In addition to the aforementioned primary disturbance noises, the telescope pointing system is also subject to other noise influences: (1) actuator drive noise, which is the torque noise generated by the piezoelectric actuators in the telescope pointing mechanism [11], as illustrated in Figure 7a; (2) sensor noise. To achieve angle measurements at the nanoradian level, we utilized differential wavefront sensing (DWS) for angular measurements [23], with the DWS signal serving as the feedback control signal for the telescope pointing system.…”

“…Wang et al [10], using a stacked recursive neural network adaptive controller, addressed the issue of insufficient control precision, achieving precise pointing requirements at the nanoradian level between satellites and telescopes. Deng et al [11] designed a frequency-divided controller that coordinates the spacecraft attitude control loop and the telescope attitude control loop, improving the overall performance and pointing stability of the system. Cao et al [12] proposed a closed-loop control method for a fine stabilization system based on dual-port adaptive internal model control, enabling the disturbance compensation of the space telescope's fine stabilization system with lower steady-state error and a broader frequency range.…”

Constellation attitude tracking control of the space gravitational wave observatory under configuration disturbances

“…Due to the introduction of disturbance and error compensator, the order of the system's equivalent controller will be increased. Taking into account the system order and performance optimization, considering that a simple structure and easy to implement, we design the basic controller C b (s) as a finite frequency controller, where u max is the torque output limit, z max is the output limit, ω 1 = 2π × 10 −4 rad/s, ω 2 = 2π rad/s, with constrains [17] :…”

“…Wang et al [16] used sliding mode control technique combined with neural network optimization for higher precision pointing control. Deng et al [17] proposed a frequency division control method for high precision line of sight attitude tracking control. However, the existed research mainly focuses on attitude maintance for space based gravitational wave detectors, the attitude-position coupling of 3 spacecrafts, i.e., formation and attitude coupling problems and compatibility considerations need to be deepened.…”

Continuous Low-Thrust Maneuver Planning for Space Gravitational Wave Formation Reconfiguration Based on Improved Particle Swarm Optimization Algorithm

“…The main objective of this study is to develop a minimum-fuel spacecraft formation reconfiguration strategy for future space missions, such as space gravitational wave detectors, a distributed remote sensing cluster or solar satellite systems, etc. [ 5 , 8 , 26 , 27 , 28 ]. Firstly, a configuration reconfiguration scheme suitable for space gravitational wave detection formation is proposed, which is based on the concept of virtual formation.…”