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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...
To meet the performance requirements of real-time and high accuracy for autonomous docking of modular self-reconfigurable CubeSats, a vision-based method is proposed by setting a cooperative target on a CubeSat and combining with Fractional-Order Darwinian Particle Swarm Optimization algorithm. Firstly, a monocular camera is utilized to grab images of the cooperation target. Then an image intelligent...
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...
The biomimetic principle applied in the deployable structure design process has important significances in engineering reality. Principle in nature provides numerous design solutions for innovative deployable structures. Meanwhile, it has initiated a new area for biomimetic research. In this paper, the mechanism of butterfly eclosion deploy process is introduced. According to the butterfly wings eclosion...
According to the depth estimation of the Zooming images, the technology about the calibration of the optical center displacements of different focus is studied by combining the zooming camera features and the general methods of camera calibration. The thick lens model is proposed, and the external parameters of different focus are calibrated by using the method of plane templates. The experiment which...
Quadrotor is a strong coupling, under actuated complex system with multi inputs and multi outputs. In this paper, the quadrotor UAV model was presented at first. In order to control the position and attitude respectively, a nested loops control strategy was employed. The full control was divided into two parts, i.e. position control and attitude control. Both a PD controller and a fuzzy adaptive PD...
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 prototype design and system analysis of a novel biomimetic eyeball-like robot (BEBOT) with mechanism implementing the process of accommodation. The mechanism proposed is inspired by the evidence of anatomy results of human eyeball, which has the ability to percept visual information of target object from far to near distance clearly. BEBOT implements this function by bio-inspired...
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...
This paper presents a new video synthesis method for flow patterns. We can use it to synthesize video of natural phenomena that exhibit continuous flow patterns. It is based on flow-based video synthesis algorithm, and combines partial ideas of graph cuts algorithm. This algorithm can process input videos of natural phenomena of flow patterns (e.g. rivers, flames and waterfalls), and synthesize more...
A shape-shifting robot, which named “AMOEBA-I”, has diverse configurations. The accessibility of the robot can be reinforced in the narrow space by changing the configurations. In this paper, a path planning method is presented corresponding to the unique reconfigurable ability of the robot. This method can automatically adjust the computational cost according to the distribution of obstacles in robot's...
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 shape-shifting robot with diverse configurations, named "AMOEBA-I" has been developed for search and rescue tasks. The accessibility of this robot to uneven environments was efficiently enlarged by changing its configurations. In this paper, for optimizing the path of the robot through an environment containing static polygonal obstacles, we present an adaptive path planning method for...
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...
The complex environment requires mobile robots to possess high capability of obstacle negotiation. Cooperative negotiation is proposed to endow the AMOEBA-I robot with capability of obstacle negotiation and to reinforce the adaptability of the robot in unstructured environment. A mathematical model is established. The relationship between the height that the robot can overcome and angle with gravity...
A roboticized rock abrasion tool is considered to replace the geologistpsilas rock hammer to remove dusty and weathered surfaces of the rock. A roboticicized rock abrasion tool with three degrees of freedom has been developed in this paper. Planetary transmission system is used in the grinding driving system with two inputs (rotation motor and revolution motor) and two outputs (grinding wheel and...
An autonomous control system is developed for a shape-shifting robot "AMOEBA-I" to be possibly used in the urban terrain. Based on the sensors including GPS, electronic compass, inclinometer and encoder, the autonomous motions of AMOEBA-I are realized. The shape-shifting motion, navigation, obstacle-climbing motion, and obstacle avoidance are all autonomously performed in unstructured environments...
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