Modeling, Control, and Validation of Electrohydrostatic Shock Absorbers

2015 ◽  
Vol 137 (1) ◽  
Author(s):  
Renato Galluzzi ◽  
Andrea Tonoli ◽  
Nicola Amati

The implementation of variable damping systems to increase the adaptability of mechanical structures to their working environment has been gaining increasing scientific interest, and numerous attempts have been devoted to address vibration control by means of active and semi-active devices. Although research results seem promising in some cases, the proposed solutions are often not able to fulfill requirements in terms of compactness and simplicity on one hand, and dynamic performance on the other. In this context, the present paper discusses the modeling and control of an electrohydrostatic actuation (EHA) system for its implementation as a damping device. A model of the device is proposed and analyzed for design purposes. Subsequently, a damping control strategy is presented. Finally, a case study introduces and validates an EHA prototype for helicopter rotor blade lead–lag damping.

2011 ◽  
Vol 403-408 ◽  
pp. 3758-3762
Author(s):  
Subhajit Patra ◽  
Prabirkumar Saha

In this paper, two efficient control algorithms are discussed viz., Linear Quadratic Regulator (LQR) and Dynamic Matrix Controller (DMC) and their applicability has been demonstrated through case study with a complex interacting process viz., a laboratory based four tank liquid storage system. The process has Two Input Two Output (TITO) structure and is available for experimental study. A mathematical model of the process has been developed using first principles. Model parameters have been estimated through the experimentation results. The performance of the controllers (LQR and DMC) has been compared to that of industrially more accepted PID controller.


2019 ◽  
pp. 20-66
Author(s):  
Heba Elkholy ◽  
Maki K. Habib

This chapter presents the detailed dynamic model of a Vertical Take-Off and Landing (VTOL) type Unmanned Aerial Vehicle (UAV) known as the quadrotor. The mathematical model is derived based on Newton Euler formalism. This is followed by the development of a simulation environment on which the developed model is verified. Four control algorithms are developed to control the quadrotor's degrees of freedom: a linear PID controller, Gain Scheduling-based PID controller, nonlinear Sliding Mode, and Backstepping controllers. The performances of these controllers are compared through the developed simulation environment in terms of their dynamic performance, stability, and the effect of possible disturbances.


2014 ◽  
Vol 960-961 ◽  
pp. 808-812
Author(s):  
Wen Qiang Xu ◽  
Zhi Yong Dai ◽  
Qiang Gang Wang ◽  
Shu Pan ◽  
Nian Cheng Zhou

This paper presents a control strategy of solid oxide fuel cell (SOFC) generation system integrated into microgrid. To enhance the dynamic response of SOFC, storage battery is paralleled via a DC bus, and the hysteretic control of bi-directional DC-DC converter is adopted. The common DC-AC inverter adopts an improved droop control. The active synchronization control is applied to ensure the smooth mode transition of microgrid. The simulation results show the dynamic performance of SOFC generation system in different operation modes.


1987 ◽  
Vol 20 (5) ◽  
pp. 223-229
Author(s):  
P.B. Luh ◽  
Yu-Chi Ho ◽  
Ying-Ping Zheng ◽  
Jong-Ming Wu ◽  
Qing-Yu Wang ◽  
...  

2014 ◽  
Vol 621 ◽  
pp. 462-469 ◽  
Author(s):  
Ming Zhu Zhang ◽  
Zhi Li Zhou

To develop the control system of multi-range hydro-mechanical continuously variable transmission (HMCVT), a model of a multi-range HMCVT is built using the principle of dynamics. According to the characteristic of power split, HMCVT is separated as axes set, variable displacement pump-motor system, clutch set. With wheel tractor as application instance, the whole model of vehicle power train is made, which includes the engine, HMCVT, running system and control system. Based on the theory of Finite State Machine, an automatic control method of speed change and range shift is present, which employs the throttle value, engine speed, range number and transmission ratio as the control parameters. The dynamic characteristic of automatic speed changing and ranges shifting is simulated. The result indicates that the model can correctly represent the dynamic characteristic of HMCVT, the engine can run at the optimal working point, the multi-range HMCVT can shift range steadily and change transmission ratio continuously when the load changes, the circularly shift range is avoided. The model can be used conveniently for the analysis of vehicle dynamic performance and the research of multi-range HMCVT control method.


Author(s):  
Heba Elkholy ◽  
Maki K. Habib

This chapter presents the detailed dynamic model of a Vertical Take-Off and Landing (VTOL) type Unmanned Aerial Vehicle (UAV) known as the quadrotor. The mathematical model is derived based on Newton Euler formalism. This is followed by the development of a simulation environment on which the developed model is verified. Four control algorithms are developed to control the quadrotor's degrees of freedom: a linear PID controller, Gain Scheduling-based PID controller, nonlinear Sliding Mode, and Backstepping controllers. The performances of these controllers are compared through the developed simulation environment in terms of their dynamic performance, stability, and the effect of possible disturbances.


2014 ◽  
Vol 2014 ◽  
pp. 1-21 ◽  
Author(s):  
Yifei Wu ◽  
Zhihong Wang ◽  
Yuanyuan Li ◽  
Wei Chen ◽  
Renhui Du ◽  
...  

A novel approach for modeling and control of servo systems with backlash and friction is proposed based on the characteristic model. Firstly, to deal with friction-induced nonlinearities, a smooth Stribeck friction model is introduced. The backlash is modeled by a continuous and derivable mathematical function. Secondly, a characteristic model in the form of a second-order slowly time-varying difference equation is established and verified by simulations. Thirdly, a composite controller including the golden-section adaptive control law and the integral control law is designed and the stability of the closed-loop system is analyzed. The simulation and experimental results show that the proposed control scheme is effective and can improve the steady-state precision and the dynamic performance of the servo system with backlash and friction.


Author(s):  
Xin Wang

In this work, the models and control strategy of the Electric Servo-torque System(ESS) which is used as an experiment rig for conducting dynamic performance and stability tests of aerial vehicle control surface actuation systems are presented. The detailed dynamics of the load motor and loaded flight actuator’s rotating movement in the ESS are analyzed, leading to an integrated load torque synchronization system. The kinematic dynamics of the loaded control surface driving actuator is an important consideration to estimate the trend of torque variation and to improve the performance of the load system. The load control method is expressed in terms of a multi-loop torque control law, which uses feedback and feedforward loops to meet system design requirements. Numerical examples together with experimental results are included to illustrate the effectiveness of the proposed models and control parameters. This brief addressed a specific utilization of the loaded actuator’s dynamics, revealing that it can reduce both the phase lag and the amplitude gain of the load torque in the Electric Servo-torque System.


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