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Kou Y.-M.,Aerospace Dongfanghong Development Ltd. | Kou Y.-M.,Harbin Institute of Technology | Yuan Q.,Aerospace Dongfanghong Development Ltd. | Ji Y.-B.,Aerospace Dongfanghong Development Ltd. | And 2 more authors.
Yuhang Xuebao/Journal of Astronautics | Year: 2017

A control strategy for single axis pointing of micro-satellites is proposed which uses only magnetictorquers. This method is useful in satellites' safe modes and other specific situations. It contains the following steps: firstly, a geometry algorithm is utilized to extend the collection of the rotation axis to a plane, along which the current and target directions can coincide; secondly, an angle acceleration plane is found by affine transaction from the perpendicular plane of the local geomagnetic field with the satellite's inertial matrix; thirdly, a controller that works along the intersecting line of the rotation axis plane and the angle acceleration plane is constructed to control both the rotating direction and the speed. Compared with the existing methods, this new method has advantages such as no additional disturbance from magnetic torque, less limitation from orbit shape as well as inertia products need not to be zero. The performance of the controller is validated in simulation, in which the Sun pointing and the Earth pointing with single axis are realized. © 2017, Editorial Dept. of JA. All right reserved.

Liu H.,Harbin Institute of Technology | Liang B.,Harbin Institute of Technology | Xu W.,Harbin Institute of Technology | Di Z.,Harbin Institute of Technology | Wang X.,Aerospace Dongfanghong Development Ltd
International Journal of Advanced Robotic Systems | Year: 2012

Robotic systems are expected to play an increasingly important role in future space activities with the development of space technology. One broad area of application is in the servicing, construction and maintenance of satellites and large space structures in orbit. Fine manipulation technology is very important for space robots to be able to perform these tasks, since it must ensure safe and reliable interaction with objects or the environment. In order to assure the task is accomplished successfully, ground experimentations are required in order to verify key planning and control algorithms before the space robot is launched. In this paper, based on the concept of a hybrid approach combining the mathematical model with the physical model, a ground experiment system is set up, which is composed of two industrial robots, global and hand-eye visual equipment, six-axis force/torquesensors, guide rail and four computers. Many control approaches of fine manipulation, such as compliance control, impedance control, hybrid force/position control, intelligent control and so on, can be verified using this system. As an example, a contour curves tracking experiment based on the compliance control strategy is performed. Experiment results show that the ground system is very useful for verifying the dexterous manipulation technology of space robots. © 2012 Liu et al.

Mu Z.,Harbin Institute of Technology | Mu Z.,Aerospace Dongfanghong Development Ltd. | Yang Y.,Harbin Institute of Technology | Xu W.,Harbin Institute of Technology | And 2 more authors.
Proceedings of the World Congress on Intelligent Control and Automation (WCICA) | Year: 2015

In this paper, we proposed a unified framework to model the obstacles, and a method to plan the 3-D collision-free trajectory for a redundant space manipulator. Firstly, the exterior contour of an obstacle was enveloped by one or several geometric primitives, such as cylinder, sphere, cone, cube, and so on. Secondly, the surface of its envelope was represented by a super-quadratic function, whose parameters can be adjusted to describe different shapes and dimensions. Combining with the pose and motion describing, the complete properties of an obstacle were included in a unified framework. Thirdly, a trajectory planning method based on gradient projection was presented to avoid the obstacles moving in the 3-D workspace. Instead of Euclidean distance, the normalized pseudo-distance was addressed and used as the objective function to be optimized. Finally, simulation studies of typical on-orbital missions with different obstacles were performed. Simulation results verified the unified obstacle model and 3-D collision-free trajectory planning method. © 2014 IEEE.

Gao X.,Harbin Institute of Technology | Gao X.,Aerospace Dongfanghong Development Ltd. | Liang B.,Harbin Institute of Technology | Qiu Y.,Harbin Institute of Technology
2014 13th International Conference on Control Automation Robotics and Vision, ICARCV 2014 | Year: 2014

In far range proximity of GEO on-orbit service, a space robot cannot reach desired position exactly by using two impulses C-W guidance and control law. To overcome this problem, a multiple impulses C-W guidance and control law with mid-correction is proposed. The guidance problem is transformed to nonlinear programming with constraints according to the error of final position. The fuel optimal solution is gotten by Particle Swarm Optimization algorithm with constraints. Firstly, the model of multiple impulses guidance is produced based on C-W law. Secondly, the detail of fuel optimal solution algorithm is presented by using PSO. Thirdly, numerical simulations are studied to verify the PSO algorithm of multiple impulses guidance under different conditions. The results show that this method is feasible and effective. © 2014 IEEE.

Du X.,Harbin Institute of Technology | Liang B.,Harbin Institute of Technology | Xu W.,Harbin Institute of Technology | Wang X.,Aerospace Dongfanghong Development Ltd. | Yu J.,Aerospace Dongfanghong Development Ltd.
Proceedings of the 2012 International Conference on Virtual Reality and Visualization, ICVRV 2012 | Year: 2012

In order to perform the on-orbit servicing mission, the robotic system is firstly required to approach and dock with the target autonomously, for which the measurement of relative pose is the key. It is a challenging task since the existing GEO satellites are generally non-cooperative, i.e. no artificial mark is mounted to aid the measurement. In this paper, a method based on natural features is proposed to estimate the pose of a GEO satellite in the phase of R-bar final approach. The adapter ring and the bottom edges of the satellite are chosen as the recognized object. By the circular feature, the relative position can be resolved while two solutions of the orientation are obtained. The vanishing points formed by the bottom edges are applied to solve the orientation-duality problem so that the on board camera requires no specific motions. The corresponding algorithm for image processing and pose estimation is presented. Computer simulations verify the proposed method. © 2012 IEEE.

Jia Q.,Harbin Institute of Technology | Zhang Y.,Harbin Institute of Technology | Zhang Y.,Aerospace Dongfanghong Development Ltd | Li C.,Harbin Institute of Technology | Chen X.,Harbin Institute of Technology
Journal of Systems Engineering and Electronics | Year: 2014

This paper addresses a problem of observer-based sensor fault reconstruction for continuous-time systems subject to sensor faults and measurement disturbances via a descriptor system approach. An augmented descriptor plant is first formulated, by assembling measurement disturbances and sensor faults into an auxiliary state vector. Then a novel descriptor state observer for the augmented plant is constructed such that simultaneous reconstruction of original system states, sensor faults and measurement disturbances are obtained readily. Sufficient conditions for the existence of the proposed observer are explicitly provided, and the application scope of the observer is further discussed. In addition, an extension of the proposed linear approach to a class of nonlinear systems with Lipschitz constraints is investigated. Finally, two numerical examples are simulated to illustrate the effectiveness of the proposed fault-reconstructing approaches. © 2013 Journal of Systems Engineering and Electronics.

Yan L.,Harbin Institute of Technology | Mu Z.,Harbin Institute of Technology | Mu Z.,Aerospace Dongfanghong Development Ltd | Xu W.,Harbin Institute of Technology | Xu W.,Aerospace Dongfanghong Development Ltd
Conference Proceedings - IEEE International Conference on Systems, Man and Cybernetics | Year: 2014

The arm-angle was often used to parameterize the self-motion of S-R-S (Spherical-Revolute-Spherical) redundant manipulators when solving the inverse kinematics. However, there were some shortcomings for previous works: Existing algorithm singularity or not suitable for configuration control. In this paper, we proposed an analytical resolution method based on dual arm-angle parameterization. Using two orthogonal vectors to define two absolute reference planes, we got two arm-angles which satisfy a specific condition. Since there is always at least one arm angle to represent the redundancy, the algorithm singularity problem does not exist. The "dual arm-angle" method keeps the advantages of "arm-angle", and overcomes the shortcomings of the traditional methods. Another contribution of this paper is that we derived the absolute reference elbow attitude matrix 0 0 3R , which is the key for the analytical inverse kinematics resolution but was not addressed in the previous paper. Simulation results for a general case and an algorithm singularity case verified the presented method. © 2014 IEEE.

Jia Q.-X.,Harbin Institute of Technology | Zhang Y.-C.,Harbin Institute of Technology | Zhang Y.-C.,Aerospace Dongfanghong Development Ltd. | Shen Y.,Harbin Institute of Technology | Wu L.-N.,Harbin Institute of Technology
Xi Tong Gong Cheng Yu Dian Zi Ji Shu/Systems Engineering and Electronics | Year: 2012

A robust fault reconstruction method based on the iterative learning-unknown input observer (IL-UIO) is proposed for actuator fault in satellite attitude control systems (ACS). Firstly, considering space disturbance torque, model uncertainties and gyro drift, the nonlinear model of attitude control is established when a three-axis stability satellite runs in a small angle maneuver. Secondly, based on the disturbance decoupling principle of UIO and H ∞ control theory, the IL-UIO is designed to estimate attitude Euler angles and angular velocities, and the IL algorithm is used to achieve actuator robust fault reconstruction. Using the Lyapunov stability theorem, the stability of IL-UIO and the ultimate boundedness of dynamic fault errors are proved, the parameter matrixes of IL-UIO are solved effectively in terms of linear matrix inequality (LMI) toolbox. Finally, mathematical simulation is performed to validate the solution in satellite closed-loop ACS, and simulation results demonstrate the effectiveness of the proposed algorithm.

Liu H.-D.,Harbin Institute of Technology | Liang B.,Harbin Institute of Technology | Liang B.,Aerospace Dongfanghong Development Ltd. | Li C.,Aerospace Dongfanghong Development Ltd. | And 2 more authors.
Yuhang Xuebao/Journal of Astronautics | Year: 2012

Two coordinated control methods, joint damping control and parameterised joint function coordinated control are proposed in this paper for stabilizing a spacecraft-captured coupling system based on conservation of angular momentum, for the coupling system may be unstable due to the change in mass characteristics and momentum of the coupling system. In these methods, management and re-distribution of angular momentum are used to stabilize the coupling system by planning and controlling the velocity of the flywheel and joints, the second method can be the hope of configuration, and is very convenient for on-orbit service. These methods using real flywheel as an actuator for momentum exchange are realizable in engineering. Simulation results show that these methods are effective.

Sun R.,Aerospace Dongfanghong Development Ltd. | Wang T.,Shenzhen Pingshan Middle School | Lv H.,Aerospace Dongfanghong Development Ltd.
Proceedings of the International Astronautical Congress, IAC | Year: 2013

At present the technology of SMD encapsulation components at home and abroad has been mature, but also has been verified and applied widely in the market. Its application has certain practical significance in the micro aerospace industry, is one of the ways to promote the micro aerospace industry and technology upgrading. This paper first introduces the application status and technical background of SMD encapsulation components in the market. Through calculation of thermal stress, analysis of dynamics and conducting reasonable encapsulation design and external structural mechanics design of SMD components, can improve the reliability in the application and optimize the spacecraft in weight and size. The analysis results show that the technology will promote the rapid promotion of micro spacecraft products which include the components, equipments, micro spacecraft and so on. Copyright © 2013 by the International Astronautical Federation.

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