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In this paper, a novel recursive method to identify the moment of inertia parameters of on-orbit spacecraft is proposed. Different from the frequently-used momentum conservation and least squares approach, the presented method is implemented based on the Projection Approximation Subspace Tracking (PAST), and the moment of inertia parameters can be determined recursively from the system state-space...
For accurate error estimation, a stereo reconstruction error analysis method for spatial circle is presented. The error estimation model is proposed based on error transfer analysis. The error expressions are derived in the processes of calibration, matching and reconstruction. Then, the reconstruction error estimation model of spatial circle is established. A method of estimating the reconstruction...
When the astronauts are running on the astronaut treadmill for healthy exercise, their impact force will have serious disturbances on almost all the on-orbital science experiments. To solve this problem, a parallel passive vibration isolation system is designed for the astronaut treadmill. The proposed passive vibration isolation system can also restrain the high-frequency disturbance aroused from...
This paper presents a model reference adaptive PID controller for controlling a novel compliant flexures-based XY micro-positioning stage driven by electromagnetic actuators. The stage is specially designed by employing double four-bar parallelogram flexures and four non-contact electromagnetic force actuators to realize the kinematic decoupling and force decoupling respectively. Based on preliminary...
The stator flux-oriented vector control theory is adopted for megawatt double-fed induction generator (DFIG). Rotor excitation current is regulated according to grid voltage and rotor speed to realize no-load grid connection of DFIG. The control strategy is switched after grid connection successfully to realize maximum power point tracking (MPPT) and power decoupled control. The control of the rotor-side...
A back-to-back PWM converter is used as the excitation power supply for the doubly-fed induction generator (DFIG) wind power generation of variable speed constant frequency (VSCF). The mathematical model and control strategy of converter which is connected between rotor and grid is analyzed. Grid-side converter adopts grid voltage oriented control scheme for achieving the stability of DC-link voltage,...
The purpose of this research is to optimize control and enhance performance for a variable speed constant frequency (VSCF) doubly-fed induction generator (DFIG) wind turbine generation system by using fuzzy logic controller. The control of the rotor-side converter is realized by stator flux oriented control and the fuzzy controller performs robust speed control. The control of the grid-side converter...
The synthesis of the mathematics model is done using three S-functions based on state equation, thus simplifying and accelerating the implementation of DFIG. The VSCF DFIG wind power generation is transient response proceeding, which is influenced by operation characteristics of generator before and after grid connection. A complete simulation model of VSCF DFIG wind power generation based on Matlab...
In this paper, we present a four-layered representing architecture for the configurations of a link-type reconfigurable mobile robot. Decimal numbers are used to represent all these possibilities in joint space. Binary codes are introduced to represent the links with consideration of adjacent interventions. To find out all the mobile configurations completely and accurately, configuration matrices...
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