This paper presents a modified methodology based on the model reference adaptive control (MRAC) for tracking and stability with gravity compensation for the 5-link single support phase lower limb exoskeleton with exte...
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This paper presents a modified methodology based on the model reference adaptive control (MRAC) for tracking and stability with gravity compensation for the 5-link single support phase lower limb exoskeleton with external disturbance. Different from conventional methods, the proposed method is based on MRAC with adaptive error gain in the presence of external disturbance. Asymptotical stability of the system is investigated by choosing an appropriate lyapunov function, that ensures the convergence of tracking error to zero. The effectiveness of proposed method has been verified with the help of simulation example.
A design of integrated pitch-yaw acceleration autopilot based on sliding mode control (SMC) with a nonlinear observer (NLO) is proposed for skid to turn (STT) velocity-varying missile. Missile autopilot design faces a...
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ISBN:
(纸本)9781509017393
A design of integrated pitch-yaw acceleration autopilot based on sliding mode control (SMC) with a nonlinear observer (NLO) is proposed for skid to turn (STT) velocity-varying missile. Missile autopilot design faces a great challenge owing to nonlinear aerodynamics, missile parameters' variation, coupling effect between channels, and unavailability of measuring all states. Moreover, the autopilot should be designed for the entire flight envelope, including boosting, sustaining, and gliding phases where fast variation of velocity and parameters exists. Thus the robustness against the quick variation of velocity and parameters is exceedingly required. The suggested missile model considers the velocity variation, the gravity effect, the missile parameters' variation. The proposed autopilot controls the normal acceleration of pitch-yaw channels simultaneously using multiple sliding surfaces and reaching laws. NLO is proposed to estimate the immeasurable states and its inputs are the measurable missile angular rates and its accelerations, and control signals. The closed loop system stability including the NLO stability is discussed. Finally, Numerical simulation is established to evaluate performance of the proposed acceleration autopilot.
This article combines the ideas of exoskeleton with hybrid system and proposes a hybrid model of *** the walking process of human-exoskeleton coupling system can be divided into four different contact phases,single su...
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ISBN:
(纸本)9781509009107
This article combines the ideas of exoskeleton with hybrid system and proposes a hybrid model of *** the walking process of human-exoskeleton coupling system can be divided into four different contact phases,single support left,double support I,single support right and double support *** four different contact situations yield a hybrid model where continuous nonlinear ordinary differential equations(ODEs) describe the dynamics in the contact phases and the commutations between the discrete phases are marked by collision and detachment *** obtain the stable and smooth synthesized gait for human-exoskeleton coupling system,the zero-moment-point(ZMP) theory and three spline interpolation method have been used *** PID controller is used during each phases to test the model and *** whole design of hybrid model and control method have been simulated in MATLAB and the results are presented to illustrate the effectiveness of the proposed control strategy and the stability of planned gait.
Person re-identification is one of the hot topics in computer vision. How to design a robust feature representation to identify pedestrians is a key problem for person reidentification. In this paper, a feature repres...
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Person re-identification is one of the hot topics in computer vision. How to design a robust feature representation to identify pedestrians is a key problem for person reidentification. In this paper, a feature representation based on Multi-Statistics Cascade on Pyramid(MSCP) is proposed for person re-identification. The MSCP feature is composed of deep PCA network feature and hand-crafted features of Local Maximal Occurrence(LOMO) feature and color *** can characterize the pedestrian images precisely from both global and local views. The Cross-view Quadratic Discriminant Analysis(XQDA) is employed to learn the distance metric of MSCP features. And then a novel re-identification method based on MSCP and XQDA is achieved. Experimental results on VIPeR Dataset demonstrate that our proposed method can achieve superior identification performance compared with six state-of-art methods.
Material flow characterization is important in the process industries and its further automation. In this study, close-to-laminar pulp suspension flows are analyzed based on double-exposure images captured in laborato...
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A proposed method for discrete tracking based on piecewise continuous systems(PCS) is applied to network control *** kinds of event-triggered mechanism(ETM),including linear combination of state error and reference tr...
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ISBN:
(纸本)9781467397155
A proposed method for discrete tracking based on piecewise continuous systems(PCS) is applied to network control *** kinds of event-triggered mechanism(ETM),including linear combination of state error and reference trajectory error based mechanism and predicted tracking error based mechanism,are combined with the PCS controller respectively pointing at a linear time-invariant system with disturbances for saving network bandwidth where discrete detect is adopted.A trade-off can be made between the tracking performance and the number of transmissions by changing some *** of event-triggered control system can be realized by *** comparison between the two kinds ETM and the periodic time-triggered mechanism(P-TTM) is conducted via a numerical ***,the mainstream ETM is also studied in simulation to compare with the two proposed ETM in this paper.
The notion of elastic scattering coefficients (ESC) is introduced to address a broad range of inverse scattering and imaging problems in elastic media. The link between scattering amplitudes and ESC of small inclusion...
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This paper presents the Cramer-Rao Bound (CRB) of time-difference-of-Arrival (TDOA) estimation for frequency-hopping (FH) signals, which has still not been reported in the open literature. The CRBs are derived in clos...
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SCANSAR and TOPS SAR are two typical wide swath modes, which increase the swath by periodically switching the incidence angle of antenna among different subswath from near to far range. Sparse signalprocessing techni...
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This paper proposes a method to identify the hybrid modulation signals. Firstly, the method utilizes instantaneous frequency (IF) of signals combined with histogram to classify conventional signals and hybrid modulati...
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ISBN:
(纸本)9781849199940
This paper proposes a method to identify the hybrid modulation signals. Firstly, the method utilizes instantaneous frequency (IF) of signals combined with histogram to classify conventional signals and hybrid modulation signals. Then an improved signal segmentation method is used to resolve the hybrid modulation signals to conventional signals. Experimental results show that the proposed method can identify seven kinds of typical radar signals, and achieve 94% recognition accuracy when SNR is 3dB.
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