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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. Source

Li M.,Harbin Institute of Technology | Wang S.-Y.,Harbin Institute of Technology | Zhang Y.-C.,Harbin Institute of Technology | Zhang Y.-C.,Aerospace Dongfanghong Development Ltd | Li H.-Y.,Harbin Institute of Technology
Xi Tong Gong Cheng Yu Dian Zi Ji Shu/Systems Engineering and Electronics | Year: 2015

For the satellite autonomous navigation system subjects to model uncertainties, external disturbances and noises, the unscented Kalman filter (UKF) method has low accuracy, poor tracking ability and poor robustness. An improved strong tracking square-root unscented Kalman filter (STSRUKF)-based autonomous navigation method is proposed. For the navigation purpose, star sensors and optical navigation cameras are used in this method, and the indirect measurement vector is transformed to observables through a transition equation. To avoid the problem that negative zero weights of sigma points and great calculation errors in square-root UKF (SRUKF) design for high-order systems, a modified square-root decomposition method is applied for the SRUKF design to improve the stability of the SRUKF. In addition, based on strong tracking filters (STF), multiple adaptive fading factors in adjustment covariance matrix are adopted so that the STSRUKF has better tracking ability, better robustness against model uncertainties and better estimation accuracy. Finally, the STSRUKF-based method is applied to the satellite autonomous navigation systems, and simulation results are provided to verify the effectiveness and practicability of the proposed approach. ©, 2015, Chinese Institute of Electronics. All right reserved. Source

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. Source

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. Source

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. Source

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