Flight Test Results of the Microgravity Active Vibration Isolation System in China’s Tianzhou-1 Mission

Abstract

The Microgravity Active vibration Isolation System (MAIS) was operated on China's first cargo-spacecraft Tianzhou-1, which was launched on April 20, 2017 and re-entered atmosphere and burned on September 22, 2017. In this article, the flight test results of MAIS is presented. The results are evaluated in terms of the performances of microgravity acceleration and vibration attenuation under control. Firstly, the system configuration of MAIS on Tianzhou-1 is described, including operating modes, acceleration measurement, and control schemes. Then, two control performance indices, namely, microgravity acceleration and vibration attenuation, are introduced, followed by their definitions and methods of calculation. Subsequently, the flight test results of MAIS are described in detail. The microgravity acceleration under a PID (Proportional-Integral-Derivative) controller is at the order of 10 −7-10 −6 m/s 2 in the frequency band of 0.01-10 Hz, and the performance of vibration attenuation reaches −20 dB at frequencies higher than 0.2 Hz. The flight test results show that MAIS in the TZ-1 mission performed well and achieved the expected control performance of microgravity vibration isolation in orbit. Finally, some experiences and lessons learned are summarized, which can serve as a benchmark reference to develop MAIS-like devices on board China's Space Station in the near future.

Microgravity disturbance analysis on Chinese space laboratory

“…The controller sample acceleration signals from its Q-ACC and relative position signals from the position sensor detector, calculates the feedback current, and then drives electromagnetic coils to compensate the disturbance. 19,20 The close-loop control algorithm includes two kinds of strategies: position-following control uses the relative position as feedback, while acceleration-following control directly uses acceleration signals as feedback, but the relative position only to avoid collisions. The effect of active control is actually like a low-stiffness magnetic spring with the low-band frequency point.…”

“…It has the vibration isolation ability of 0–40 dB in the frequency of 0.03–200 Hz, and its active control ability could also provide calibration excitation signals for ES-ACC. Chinese Academy of Sciences (CAS) started related research since 2010 18–20 and MAIS was successfully applied on TZ-1. MAIS also has two three-axis Q-ACCs for measuring vibrations across larger measuring ranges to the level better than 7.5 × 10 −1 m/s 2 and wider frequency bands of 0–250 Hz.…”

Dynamic characteristics modeling of rotary platform installed on board of a small spacecraft

“…Thus, the direction for meeting the requirements for micro-accelerations for orbital space stations which include specialized laboratory modules ("Kristall" [15], "Columbus" [16], "KIBO" [17]), as well as laboratories of the class orbiting space stations "Tiangong" [18,19]). This direction is actively developing at the present time [20,21] since full-fledged pilot-scale production is possible only on large space objects. The capabilities of a modern Microgravity Isolation Mount are shown in Figure 5.…”

Using the -Bdot Algorithm to Reduce the Angular Velocity of Rotation for the Aist Small Spacecraft Pilot Model

“…Despite the fact that specialized vibration protection devices are often used to implement experiments and studies that impose restrictions on the gravity change [11][12][13][14][15], the spacecraft rotational motion should not create unacceptably high microaccelerations [16,17].…”