Comparison of active and semi-active suspension systems using robust controller

Suspension system is used to fulfil the criteria of ride comfort and road handling. In this paper, a quarter car active & semi-active suspension systems are designed using Matlab/Script software. Comparison of active & semi-active suspension systems are done using robust control theory for the control targets suspension deflection, body acceleration and body travel. H infinity controller is selected to compare the two suspensions using time domain analysis. Finally the simulation result prove the effectiveness of the active suspension system by decreasing the body acceleration & sustaining the suspension deflection and body travel outputs

轮式移动机器人瞬态模型鲁棒自适应同步终端滑模编队控制 (Robust adaptive synchronized formation control for the transient model of wheeled mobile robots with terminal sliding mode)

In the cooperative formation of wheeled mobile robots, the problem how to guarantee that mobile robots can track their own trajectories while synchronizing motions with others puts forward higher requirements on the design of control algorithms. A robust adaptive synchronized control with terminal sliding mode based on the algebraic graph theory is developed to solve this problem. Firstly, the nonlinear kinematics transient model of wheeled mobile robot is introduced. This model avoids the problem of multi-input coupling mutual interference in general kinematics model. Then, the synchronized control algorithm is designed according to the cross-coupling errors to realize the motion synchronization, and the external disturbance of the system is suppressed by the robust control. The adaptive law ensures the real-time adjustment of the switching gain. The stability analysis is carried out by using the Lyapunov method, which proves the convergence of the system tracking errors. Finally, the effectiveness of the designed algorithm is verified by MATLAB simulation

Modelling and intelligent control of vehicle climatronic systems

The modelling and control method of a vehicle climatronic system, based on MATLAB/SIMULINK, is presented. In order to achieve high modelling accuracy, a developed simulation model library is introduced. The modelling approach is described and the developed models are validated with some of experimental data obtained. The models are nonlinear, independent of fluid type and based on thermo-dynamic principles. Analysis of the cooling circuit modelling and empirical real-time control models are created by using Fuzzy logic controller and Stateflow. Both of control input and output are implemented essentially at original vehicle CAN-Bus system. Feasible digital automatic control strategy basic to fuzzy theory, hardware and software solution are given. The simulation experiment is achieved with the Hardware-in-Loop technology. This control methodology is easily operated and worth applying for any further studies or methods

Stability Analysis of parameter-excited linear Vibration Systems with Time Delay, using the Example of a Sheetfed Offset Printing Press

This article describes stability studies on parameter-excited linear vibration systems with time delay. A method for stability analysis is presented. Therefore, the transcendental transmission element of the time delay e-st is approximated as an all-pass element with the rational transfer function by means of the so-called Padé approximation. The system can be represented in the state space and the methods of the Floquet theory can also be applied to the system with approximated time delay. The process can be implemented without great effort in a standardized simulation environment such as MATLAB/SIMULINK, whereby existing models and methods can be reused. The suitability of the method is shown in the well-known example of the Mathieu differential equation with time delay. Variations between different solvers and approximation orders are described. An extended view and the transfer to an industrial application take place with the example of the drive of a sheetfed offset printing machine. The relevant vibration system is represented by an oscillator with several degrees of freedom. The belt, which couples the degrees of freedom of the drive motor and the machine, leads to a periodic (harmonic) parameter excitation of the system due to its inhomogeneous nature. The speed and position control of the drive motor (PI controller) is associated with a time delay, resulting in a system of the type described above

Reduced order modeling and sliding mode control of active magnetic bearing

Due to the accelerated growth in the field of power electronics and controller design techniques, the usage of the active magnetic bearing has picked up in industries. Active magnetic bearing helps the rotor to rotate freely without any physical contact. In brief, this paper develops a model of an active magnetic bearing using the finite element method, and its associated reduced order model, followed by the development of a robust control strategy. COMSOL software is used to perform three-dimensional simulation of an active magnetic bearing system. The state space system matrices are extracted from the finite element method, and a linear time-invariant state-space system is generated in MATLAB. Since the original system is large, the reduced order model is constructed. Then, based upon the reduced order model, a sliding mode control is designed to improve the regulation performance of an active magnetic bearing under unmodeled uncertainties. The stability analysis of closed-loop reduced order model with unmodeled uncertainties guarantees the finite time convergence of system states using Lyapunov theory. Further, it is proved that the same control law will also provide satisfactory performance for the original model using the reduced order model as an observer. The numerical simulation is carried out to illustrate the effective performance of the proposed controller for the reduced model as well as the original model with multiple initial conditions. The proposed work offers an alternative approach of using the reduced order model instead of the original model for the controller design of an active magnetic bearing.This publication was made possible by Qatar University High Impact Research Grant # [QUHI-CENG-19/20-2] from the Qatar University. The publication charges are funded by the Qatar National Library, Doha, Qatar.Scopu

TMTDyn: A Matlab package for modeling and control of hybrid rigid–continuum robots based on discretized lumped systems and reduced-order models

A reliable, accurate, and yet simple dynamic model is important to analyzing, designing, and controlling hybrid rigid–continuum robots. Such models should be fast, as simple as possible, and user-friendly to be widely accepted by the evergrowing robotics research community. In this study, we introduce two new modeling methods for continuum manipulators: a general reduced-order model (ROM) and a discretized model with absolute states and Euler–Bernoulli beam segments (EBA). In addition, a new formulation is presented for a recently introduced discretized model based on Euler–Bernoulli beam segments and relative states (EBR). We implement these models in a Matlab software package, named TMTDyn, to develop a modeling tool for hybrid rigid–continuum systems. The package features a new high-level language (HLL) text-based interface, a CAD-file import module, automatic formation of the system equation of motion (EOM) for different modeling and control tasks, implementing Matlab C-mex functionality for improved performance, and modules for static and linear modal analysis of a hybrid system. The underlying theory and software package are validated for modeling experimental results for (i) dynamics of a continuum appendage, and (ii) general deformation of a fabric sleeve worn by a rigid link pendulum. A comparison shows higher simulation accuracy (8–14% normalized error) and numerical robustness of the ROM model for a system with a small number of states, and computational efficiency of the EBA model with near real-time performances that makes it suitable for large systems. The challenges and necessary modules to further automate the design and analysis of hybrid systems with a large number of states are briefly discussed

TMTDyn: A Matlab package for modeling and control of hybrid rigid-continuum robots based on discretized lumped systems and reduced-order models

A reliable, accurate, and yet simple dynamic model is important to analyzing, designing, and controlling hybrid rigid–continuum robots. Such models should be fast, as simple as possible, and user-friendly to be widely accepted by the ever-growing robotics research community. In this study, we introduce two new modeling methods for continuum manipulators: a general reduced-order model (ROM) and a discretized model with absolute states and Euler–Bernoulli beam segments (EBA). In addition, a new formulation is presented for a recently introduced discretized model based on Euler–Bernoulli beam segments and relative states (EBR). We implement these models in a Matlab software package, named TMTDyn, to develop a modeling tool for hybrid rigid–continuum systems. The package features a new high-level language (HLL) text-based interface, a CAD-file import module, automatic formation of the system equation of motion (EOM) for different modeling and control tasks, implementing Matlab C-mex functionality for improved performance, and modules for static and linear modal analysis of a hybrid system. The underlying theory and software package are validated for modeling experimental results for (i) dynamics of a continuum appendage, and (ii) general deformation of a fabric sleeve worn by a rigid link pendulum. A comparison shows higher simulation accuracy (8–14% normalized error) and numerical robustness of the ROM model for a system with a small number of states, and computational efficiency of the EBA model with near real-time performances that makes it suitable for large systems. The challenges and necessary modules to further automate the design and analysis of hybrid systems with a large number of states are briefly discussed

Limitations of PLL simulation: hidden oscillations in MatLab and SPICE

Nonlinear analysis of the phase-locked loop (PLL) based circuits is a challenging task, thus in modern engineering literature simplified mathematical models and simulation are widely used for their study. In this work the limitations of numerical approach is discussed and it is shown that, e.g. hidden oscillations may not be found by simulation. Corresponding examples in SPICE and MatLab, which may lead to wrong conclusions concerning the operability of PLL-based circuits, are presented

SIMULATION STUDY ON PERMANENT MAGNET WIND POWER GENERATION SYSTEM BASED ON PSIM

ABSTRACT: Through systematically analyzing the mathematical theory knowledge of the small and medium-sized direct-drive permanent magnet wind power system, this paper has designed a rated power of 3kW wind power system under the environment of PSIM9.0 software. The wind power system model has been built, the back-to-back double-PWM control circuit has been designed and the simulation analysis has been completed. In the circumstance of wind speed changes, the simulation results show that the output power of the generator side is stable and the DC voltage of the inverter side is constant, which suggests the correct control strategy, the favorable system stability, and the achieved design goal. The work already done in this article provides a good platform and infrastructure for systematically analyzing the small and medium-sized wind power system. Keywords: PSIM; wind power system; PMSG; full power converter; simulation analysis. I.INTRODUCTION With the increasing depletion of fossil energy, and the continuing deterioration of global environment, the wind power generation, as one kind of new energy power generations, has been paid further attention by the governments and researchers with its unique advantages. Recently, along with the small and medium-sized independent power generation achieving strong support by the relevant national policies, small and medium-sized wind turbines have been vigorously promoted and applied Study in this paper is based on PSIM9.0 simulation software. PSIM9.0 is a dedicated simulation software for power electronics and motor control study, it has the main features of user interface simple, learning and understanding easy, operation convenient, simulation fast, simulation waveforms clear and intuitive, etc Utilizing MATLAB/Simulink and PSCAD/EMTDC respectively, literature [3] and [4] have completed the WECS related research work. These two softwares are so powerful that they can realize the complex simulation analysis, however, they launch slowly, have longer simulation time and more complex component modules and control loops while compared with PSIM. Although the simulation software in literatur