This paper aims to describe two identification methods for Hammerstein systems. Both methods are design to approximate the nonlinear component by using families of simpler functions. The first algorithm combines linea...
详细信息
ISBN:
(纸本)9781467361408
This paper aims to describe two identification methods for Hammerstein systems. Both methods are design to approximate the nonlinear component by using families of simpler functions. The first algorithm combines linear least squares with PSO to approximate both linear and nonlinear component parameters, whilst the latter redesigns the unknown coefficients approximation problem into a nonlinear least squares one and uses a modified version of Gauss-Newton algorithm to solve it. A comparison between the two methods is carried out.
There are two main approaches in the mathematical modeling of coupled systems of (bio)chemical reactions: continuous, represented by differential equations whose variables are concentrations or discrete, represented b...
详细信息
ISBN:
(纸本)9781467361408
There are two main approaches in the mathematical modeling of coupled systems of (bio)chemical reactions: continuous, represented by differential equations whose variables are concentrations or discrete, represented by stochastic processes whose variables are numbers of molecules. The latter approach is used mostly for biochemical systems with a low to moderate number of molecules of certain species and this kind of systems are typically modeled as continuous time - discrete state Markov Process. There are exact stochastic algorithms to simulate state trajectories of discrete, stochastic systems and these algorithms are based on methods that are rigorously equivalent to the Master Equation approach. Two of the most widely used methods for simulating the stochastic dynamics of a chemical system are the exact stochastic simulation algorithm (SSA, known also as Gillespie algorithm) and its approximate variant, the tau-leaping algorithm. This paper describes a modified version of SSA - First reaction method - by letting the intensity rates of the reactions to be functions of time. The importance of this adaptation is obvious when considering some classes of biological models (for example, the one involving circadian rhythm). The underlying assumptions are that the system is well stirred such that at any moment, each reactions occur with equal probability at any position, that each reaction, once occurred, completes instantaneously (there are no reactions with delay involved) and that the system is non stiff (there are no different time scales of the reactions involved).
This paper presents a new sliding surface used for induction motor control based on the sliding mode approach. The controller is developed in the dq co-ordinates. The effectiveness of the proposed control scheme is ve...
详细信息
This paper presents a new sliding surface used for induction motor control based on the sliding mode approach. The controller is developed in the dq co-ordinates. The effectiveness of the proposed control scheme is verified by numerical simulation. The main advantages of using SMC include fast response, good transient and robustness with respect to system uncertainties and external disturbances. The numerical validation results of the proposed scheme have presented good performances.
The system under study is an office building using two types of sources for heating: traditional gas boilers and energy-efficient, geothermal heat pumps. A Model-based Predictive control (MPC) strategy is suggested an...
详细信息
This paper deals with the problems of identification and control of nonlinear helicopter model. The helicopter model is achieved by closed loop identification based on grey-box structure through two steps. The first s...
详细信息
ISBN:
(纸本)9781479902255
This paper deals with the problems of identification and control of nonlinear helicopter model. The helicopter model is achieved by closed loop identification based on grey-box structure through two steps. The first step considers experiment design to minimize the number of parameters to be estimated. It employs a genetic algorithm for parameter value estimation. In the second step, a criteria function was defined for evaluation of model fitness. After that, linearization of nonlinear model was performed and linear state-space model was obtained for use in controller synthesis. The main contribution of this paper is design of loop shaping controller which is capable to control a nonlinear helicopter model. Advantage of this controller is its simpler linear structure and simpler synthesis. The quality of obtained helicopter model and effectiveness of proposed controller are verified both in simulation and experimental modes.
This paper addresses the challenges of the disturbance observer (DOB) algorithms faced with highly nonlinear electromechanical systems which are dealing with high resolution and high speed operations. It describes the...
详细信息
ISBN:
(纸本)9781479904297
This paper addresses the challenges of the disturbance observer (DOB) algorithms faced with highly nonlinear electromechanical systems which are dealing with high resolution and high speed operations. It describes the synthesis of robust and stable controllers and their applications in controlling azimuth and elevation angles of the helicopter model CE 150 supplied by Humosoft. Description of the helicopter, including its mechanical characteristics and mathematical model, is given in the paper. Tracking error, transient performances, power consumption and motor strains are used for the validation of control quality. Implementation of the controlsystem on the experimental setup is also explained. MATLAB and Simulink are used as tools for developing the simulation model of the helicopter system. Obtained simulations are showing that developed controllers provide significantly improved results even in the presence of unknown and unpredictable inputs (disturbance and noise), unpredictable and unknown dynamics, external forces (torques) and change of the system parameters.
Although it is known that Gaussian elimination method for solving simultaneous linear equations is not asymptotically optimal, it is still one of the most useful methods for solving systems of moderate size. This pape...
详细信息
Although it is known that Gaussian elimination method for solving simultaneous linear equations is not asymptotically optimal, it is still one of the most useful methods for solving systems of moderate size. This paper proposes some ideas how to speed-up the standard method. First, the trick which takes the advantage of the eventual symmetry of the system is presented, which speeds up the calculation by the factor slightly less than 2. Second, it is shown that by using some rearrangement of the calculation, it is possible to get additional speed-up, no matter whether the system is symmetric or not, although the eventual symmetry additionally doubles the execution speed. This rearrangement is performed using similar approach as in LU factorization, but retaining basic features of the Gaussian elimination method, like producing the triangular form of the system. As the required modifications in the original method are quite simple, the improved method may be used in all engineering applications where the original Gaussian elimination is used.
The proportional-integral-derivative (PID) is still the most common controller and stabilizer used in industry due to its simplicity and ease of implementation. In most of the real applications, the controlled system ...
详细信息
This paper presents the development of quadriceps muscle model based on Functional Electrical Stimulation (FES). Artificial Neural Network (ANN) were used to study the impact of stimulation frequency, pulse width and ...
详细信息
This paper presents the development of quadriceps muscle model based on Functional Electrical Stimulation (FES). Artificial Neural Network (ANN) were used to study the impact of stimulation frequency, pulse width and pulse duration towards the output torque produce by paraplegic.722 data are used by randomly divide 70% for training, 15% for validation and another 15% is for testing process. Two types of training approaches which is Levenberg Marquardt Back propagation (LM) and Resilient Back propagation (RP) are used in developing of quadriceps muscle model. The model developed are validate with the clinical data to see the accuracy of the torque output predicted with the identified parameter. From the study, LM is found to be the most accurate with accuracy up to 99.98% The identified parameter used from model developed in this study will be used to control various strategies on the Functional Electrical Stimulation (FES) system.
This paper describes the capabilities of fuzzy logic based controllers in the process of pneumatic active suspension of a heavy vehicle seat vibrations. The pneumatic active suspension system is introduced to solve co...
详细信息
This paper describes the capabilities of fuzzy logic based controllers in the process of pneumatic active suspension of a heavy vehicle seat vibrations. The pneumatic active suspension system is introduced to solve conflicting requirements of comfort and handling. The air spring is used as an active element and the damper is used as passive element for reducing vibrations. The usage of the active air spring enhances passenger comfort by comparison with passive, semi-active and active hydraulic suspension, during long time drives at a very bumpy road. Description of the seat, including its mechanical characteristics, is given in the paper. The mathematical model was created according to the physical setup of the vehicle seat at the testing laboratory. MATLAB and Simulink are used as tools for developing the simulation model of the driver seat. controlsystem description and implementation at the experimental setup using dSPACE module, are also explained. The SEAT value is used for the validation of control quality. The obtained simulations show that the developed road adaptive suspension controllers provide superior driver's comfort for most difficult types of road.
暂无评论