A method for fault diagnosis of power system of carrier rocket engine based on linear-quadratic receding time-domain algorithm

The article studies the fault diagnosis of the first-stage power system of a carrier rocket made up of multiple engines. It establishes the simplified 6-DOF nonlinear model and uses the extended Kalman filter to generate residual errors. The quadratic receding time-domain algorithm is used to detect faults, and estimation vector fault characteristics are used to estimate precisely the thrust loss degree. Faults are located with the direction of abrupt change in overload fault. The simulation results show that the method can quickly detect engine faults, estimate the thrust loss degree with fault estimation values, and locate precisely the serial number of the faulty engine of the power system made up of multiple engines. The method boosts the development of the online health management technology of the power system of a carrier rocket.

In-orbit performance of the laser interferometer of Taiji-1 experimental satellite

Taiji-1, which is the first experimental satellite for space gravitational wave detection in China, relies on key technologies which include the laser interferometer, the gravitational reference sensor (GRS), the micro-thruster and the satellite platform. Similarly to the Laser Interferometer Space Antenna (LISA) pathfinder, except for the science interferometer, the optical bench (OB) of Taiji-1 contains reference and test mass (TM) interferometers. Limited by the lower mechanical strength of the carrier rocket and by the orbit environment, the OB of Taiji-1 is made of invar steel and fused silica, and it is aimed to achieve a sensitivity of the order of 100[Formula: see text]pm/[Formula: see text]. The experimental results from in-orbit tests of Taiji-1 demonstrate that the interferometer can reach a sensitivity of 30[Formula: see text]pm/[Formula: see text] in the frequency range of 0.01–10[Formula: see text]Hz, which satisfies the requirements of Taiji-1 mission.