http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Hybrid sliding mode observer for switched linear systems with unknown inputs
Van Gorp, J.,Defoort, M.,Veluvolu, K.C.,Djemai, M. Pergamon Press [etc.] 2014 Journal of the Franklin Institute Vol.351 No.7
This paper addresses the state observation and unknown input estimation of a class of switched linear systems with unknown inputs. This class of systems may have modes in which the state is not fully observable. A state transformation allows implementing two suitable reduced-order observers. The first one, based on second order sliding mode techniques, is proposed to reconstruct the discrete state in the presence of unknown inputs. The second one, based on gathering partial information from individual modes of the switched system and on higher order sliding mode techniques, is introduced to estimate the continuous state. Then, the observer injection signal of the first second order sliding mode observer is used to estimate the unknown inputs. Simulation results highlight the efficiency of the proposed method.
Higher-Order Sliding Mode Observer for Speed and Position Estimation in PMSM
Kommuri, Suneel K.,Veluvolu, Kalyana C.,Defoort, M.,Soh, Yeng C. Hindawi Limited 2014 Mathematical problems in engineering Vol.2014 No.-
<P>This paper presents a speed and position estimation method for the permanent magnet synchronous motor (PMSM) based on higher-order sliding mode (HOSM) observer. The back electromotive forces (EMFs) in the PMSM are treated as unknown inputs and are estimated with the HOSM observer without the need of low-pass filter and phase compensation modules. With the estimation of back EMFs, an accurate estimation of speed and rotor position can be obtained. Further, the proposed method completely eliminates chattering. Experimental results with a 26 W three-phase PMSM demonstrate the effectiveness of the proposed method.</P>
Rath, J. J.,Veluvolu, K. C.,Defoort, M. Hindawi Publishing Corporation 2014 The Scientific World Journal Vol.2014 No.-
<P>The estimation of road excitation profile is important for evaluation of vehicle stability and vehicle suspension performance for autonomous vehicle control systems. In this work, the nonlinear dynamics of the active automotive system that is excited by the unknown road excitation profile are considered for modeling. To address the issue of estimation of road profile, we develop an adaptive supertwisting observer for state and unknown road profile estimation. Under Lipschitz conditions for the nonlinear functions, the convergence of the estimation error is proven. Simulation results with Ford Fiesta MK2 demonstrate the effectiveness of the proposed observer for state and unknown input estimation for nonlinear active suspension system.</P>
Simultaneous Estimation of Road Profile and Tire Road Friction for Automotive Vehicle
Rath, J. J.,Veluvolu, K. C.,Defoort, M. IEEE 2015 IEEE Transactions on Vehicular Technology VT Vol.64 No.10
<P>The longitudinal motion control of automotive vehicles is heavily reliant on information about the time-varying tire road friction coefficient. In the presence of varying road roughness profiles, the effective vertical load on each wheel varies dynamically, influencing the tire friction. In this paper, we integrated the vertical and longitudinal dynamics of a quarter wheel to form an integrated nonlinear model. In the modeled dynamics, the time-varying random road profile and the tire friction are treated as unknown inputs. To estimate these unknown inputs and states simultaneously, a combination of nonlinear Lipschitz observer and modified super-twisting algorithm (STA) observer is developed. Under Lipschitz conditions for the nonlinear functions, the convergence of the estimation error is established. Simulation results performed with the high-fidelity vehicle simulation software CarSim demonstrate the effectiveness of the proposed scheme in the estimation of states and unknown inputs.</P>
An adaptive modified super-twisting sliding mode controller
J. J. Rath,Suneel K. Kommuri,Kalyana C. Veluvolu,M. Defoort,S. Tatinati 제어로봇시스템학회 2015 제어로봇시스템학회 국제학술대회 논문집 Vol.2015 No.10
A robust higher order sliding mode algorithm combining the merits of the modified super-twisting algorithm and the adaptive super-twisting algorithm has been proposed for a class of nonlinear uncertain systems in this article. For a class of linearly growing perturbations whose upper bounds are not known, the convergence of the sliding dynamics in finite time is proven. To illustrate the effectiveness of the proposed approach, an adaptive robust controller based on the proposed algorithm is developed for the nonlinear active suspension system faced with perturbations from the road surface. Simulation results provided demonstrate the effectiveness of the proposed approach.
Suneel K. Kommuri,Jagat J. Rath,Kalyana C. Veluvolu,M. Defoort 제어로봇시스템학회 2014 제어로봇시스템학회 국제학술대회 논문집 Vol.2014 No.10
This paper presents fault-tolerant cruise control of an electric vehicle based on the permanent magnet synchronous motor (PMSM). A higher order sliding mode (HOSM) observer is designed to estimate the unknown back electro motive forces (EMFs) in the plant dynamics. A finite-time smooth estimation without low-pass filtering is obtained and the chattering phenomenon is eliminated. With the estimated back EMFs, an accurate speed estimate of PMSM can be algebraically computed. The estimated speed is provided as a feedback whenever fault occurs in the measurement speed. The corresponding torque output drives the electric vehicle (train, car) to maintain the vehicle speed to a desired vehicle speed reference. Simulations in a high fidelity CarSim confirm the validity of the overall approach.
Performance Comparison of Sliding Mode Observers for Back EMFs based Speed Estimation in PMSM
Suneel K. Kommuri,Jagat J. Rath,Kalyana C. Veluvolu,M. Defoort,S. Tatinati 제어로봇시스템학회 2015 제어로봇시스템학회 국제학술대회 논문집 Vol.2015 No.10
This paper proposes a second-order high-speed sliding mode (SHSM) observer and compares the performance with the recent higher-order sliding mode (HOSM) observer for the problem of sensorless speed estimation in the permanent magnet synchronous motor (PMSM). In which, a sigmoid function is substituted for the signum function with a variable boundary layer. A SHSM observer is proposed to provide the estimation of back electro motive forces (EMFs) that are treated as unknown inputs in the PMSM model. An accurate speed estimate of PMSM can be algebraically computed with the estimated back EMFs. The chattering phenomenon, that is commonly found in the sliding mode observers is well-reduced by replacing signum function with the sigmoid function, in comparison to the HOSM observer. Simulation results show the effectiveness of the proposed SHSM speed estimation method in comparison to the earlier HOSM observer in terms of good accuracy and chattering phenomenon.