The Experts below are selected from a list of 8655 Experts worldwide ranked by ideXlab platform
Chang-yin Sun - One of the best experts on this subject based on the ideXlab platform.
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A decoupling control for quadrotor UAV using dynamic surface control and sliding mode disturbance observer
Nonlinear Dynamics, 2019Co-Authors: Xiaobo Lin, Yao Yu, Chang-yin SunAbstract:This paper proposes a decoupling tracking controller for quadrotors using dynamic surface control (DSC) and second-order sliding mode disturbance observer (SMDO). The DSC used in this paper is improved with the sliding mode differentiators that replace the original low-pass filter, and the SMDO is utilized to restrain the influence of system uncertainties and external disturbances. In addition, instead of the roll Attitude Angle ( $$\varphi $$ φ ) and pitch Attitude Angle ( $$\theta $$ θ ), applying $$\sin {\varphi }$$ sin φ and $$\sin {\theta }$$ sin θ as control variables simplifies the analysis of stability. Moreover, a fuzzy logic-based method is utilized to compensate the influence of battery voltage changing during the procedure of thrust generation. The asymptotic tracking property of the closed-loop system is proven via the Lyapunov-based stability theory. Finally, the real-time experiment results, which contain a hovering case and rectangular path tracking case, are given to validate the practicability of the proposed method.
Xiaobo Lin - One of the best experts on this subject based on the ideXlab platform.
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A decoupling control for quadrotor UAV using dynamic surface control and sliding mode disturbance observer
Nonlinear Dynamics, 2019Co-Authors: Xiaobo Lin, Yao Yu, Chang-yin SunAbstract:This paper proposes a decoupling tracking controller for quadrotors using dynamic surface control (DSC) and second-order sliding mode disturbance observer (SMDO). The DSC used in this paper is improved with the sliding mode differentiators that replace the original low-pass filter, and the SMDO is utilized to restrain the influence of system uncertainties and external disturbances. In addition, instead of the roll Attitude Angle ( $$\varphi $$ φ ) and pitch Attitude Angle ( $$\theta $$ θ ), applying $$\sin {\varphi }$$ sin φ and $$\sin {\theta }$$ sin θ as control variables simplifies the analysis of stability. Moreover, a fuzzy logic-based method is utilized to compensate the influence of battery voltage changing during the procedure of thrust generation. The asymptotic tracking property of the closed-loop system is proven via the Lyapunov-based stability theory. Finally, the real-time experiment results, which contain a hovering case and rectangular path tracking case, are given to validate the practicability of the proposed method.
Ashish K Darpe - One of the best experts on this subject based on the ideXlab platform.
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investigations on characteristics of micro meso scale gas foil journal bearings for 100 200 w class micro power systems using first order slip velocity boundary conditions and the effective viscosity model
Microsystem Technologies-micro-and Nanosystems-information Storage and Processing Systems, 2013Co-Authors: Skylab P Bhore, Ashish K DarpeAbstract:In this paper, a modified compressible Reynolds equation for micro/meso scale gas foil journal bearings considering first order slip and effective viscosity under rarefied flow conditions is presented. The influence of rarefaction effect on the load carrying capacity, Attitude Angle, speed and frequency dependent stiffness and damping coefficients, modal impedance, natural frequencies and unbalance response is studied. From numerical analysis, it has been found that there is significant change in all the static and dynamic characteristics predicted by the no-slip model and model with effective viscosity. There is also a considerable difference between the values predicted by a model with effective viscosity and a model without effective viscosity. For a given eccentricity ratio, the influence of effective viscosity on load carrying capacity and Attitude Angle is more significant for the typical operating speed range of micro/meso scale gas turbines. The influence of effective viscosity decreases with increase in compliance of bearing structure. Similarly, the influence of effective viscosity on frequency dependent stiffness and damping coefficients increases with excitation frequency ratio. Significant change in natural frequency, modal impedance and unbalance response for model with no slip and slip with effective viscosity is observed. The influence of effective viscosity is found to be significant with increase in Knudsen number.
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Investigations on characteristics of micro/meso scale gas foil journal bearings for 100–200 W class micro power systems using first order slip velocity boundary conditions and the effective viscosity model
Microsystem Technologies, 2013Co-Authors: Skylab P Bhore, Ashish K DarpeAbstract:In this paper, a modified compressible Reynolds equation for micro/meso scale gas foil journal bearings considering first order slip and effective viscosity under rarefied flow conditions is presented. The influence of rarefaction effect on the load carrying capacity, Attitude Angle, speed and frequency dependent stiffness and damping coefficients, modal impedance, natural frequencies and unbalance response is studied. From numerical analysis, it has been found that there is significant change in all the static and dynamic characteristics predicted by the no-slip model and model with effective viscosity. There is also a considerable difference between the values predicted by a model with effective viscosity and a model without effective viscosity. For a given eccentricity ratio, the influence of effective viscosity on load carrying capacity and Attitude Angle is more significant for the typical operating speed range of micro/meso scale gas turbines. The influence of effective viscosity decreases with increase in compliance of bearing structure. Similarly, the influence of effective viscosity on frequency dependent stiffness and damping coefficients increases with excitation frequency ratio. Significant change in natural frequency, modal impedance and unbalance response for model with no slip and slip with effective viscosity is observed. The influence of effective viscosity is found to be significant with increase in Knudsen number.
Lijuan Zhou - One of the best experts on this subject based on the ideXlab platform.
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integrated navigation fusion strategy of ins uwb for indoor carrier Attitude Angle and position synchronous tracking
The Scientific World Journal, 2014Co-Authors: Qigao Fan, Jing Hui, Lijuan ZhouAbstract:In some GPS failure conditions, positioning for mobile target is difficult. This paper proposed a new method based on INS/UWB for Attitude Angle and position synchronous tracking of indoor carrier. Firstly, error model of INS/UWB integrated system is built, including error equation of INS and UWB. And combined filtering model of INS/UWB is researched. Simulation results show that the two subsystems are complementary. Secondly, integrated navigation data fusion strategy of INS/UWB based on Kalman filtering theory is proposed. Simulation results show that FAKF method is better than the conventional Kalman filtering. Finally, an indoor experiment platform is established to verify the integrated navigation theory of INS/UWB, which is geared to the needs of coal mine working environment. Static and dynamic positioning results show that the INS/UWB integrated navigation system is stable and real-time, positioning precision meets the requirements of working condition and is better than any independent subsystem.
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Integrated navigation fusion strategy of INS/UWB for indoor carrier Attitude Angle and position synchronous tracking.
The Scientific World Journal, 2014Co-Authors: Qigao Fan, Jing Hui, Lijuan ZhouAbstract:In some GPS failure conditions, positioning for mobile target is difficult. This paper proposed a new method based on INS/UWB for Attitude Angle and position synchronous tracking of indoor carrier. Firstly, error model of INS/UWB integrated system is built, including error equation of INS and UWB. And combined filtering model of INS/UWB is researched. Simulation results show that the two subsystems are complementary. Secondly, integrated navigation data fusion strategy of INS/UWB based on Kalman filtering theory is proposed. Simulation results show that FAKF method is better than the conventional Kalman filtering. Finally, an indoor experiment platform is established to verify the integrated navigation theory of INS/UWB, which is geared to the needs of coal mine working environment. Static and dynamic positioning results show that the INS/UWB integrated navigation system is stable and real-time, positioning precision meets the requirements of working condition and is better than any independent subsystem.
Yao Yu - One of the best experts on this subject based on the ideXlab platform.
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A decoupling control for quadrotor UAV using dynamic surface control and sliding mode disturbance observer
Nonlinear Dynamics, 2019Co-Authors: Xiaobo Lin, Yao Yu, Chang-yin SunAbstract:This paper proposes a decoupling tracking controller for quadrotors using dynamic surface control (DSC) and second-order sliding mode disturbance observer (SMDO). The DSC used in this paper is improved with the sliding mode differentiators that replace the original low-pass filter, and the SMDO is utilized to restrain the influence of system uncertainties and external disturbances. In addition, instead of the roll Attitude Angle ( $$\varphi $$ φ ) and pitch Attitude Angle ( $$\theta $$ θ ), applying $$\sin {\varphi }$$ sin φ and $$\sin {\theta }$$ sin θ as control variables simplifies the analysis of stability. Moreover, a fuzzy logic-based method is utilized to compensate the influence of battery voltage changing during the procedure of thrust generation. The asymptotic tracking property of the closed-loop system is proven via the Lyapunov-based stability theory. Finally, the real-time experiment results, which contain a hovering case and rectangular path tracking case, are given to validate the practicability of the proposed method.
