Robust Control of Automotive Active Seat-Suspension System Subject to Actuator Saturation

Author(s):  
Zhou Gu ◽  
Shumin Fei ◽  
Yaqin Zhao ◽  
Engang Tian

This paper deals with the problem of robust sampled-data control for an automotive seat-suspension system subject to control input saturation. By using the nature of the sector nonlinearity, a sampled-data based control input saturation in the control design is studied. A passenger dynamic behavior is considered in the modeling of seat-suspension system, which makes the model more precisely and brings about uncertainties as well in the developed model. Robust output feedback control strategy is adopted since some state variables, such as, body acceleration and body deflection, are unavailable. The desired controller can be achieved by solving the corresponding linear matrix inequalities (LMIs). Finally, a design example has been given to demonstrate the effectiveness and advantages of the proposed controller design approach.

Author(s):  
Mohammad Saber Fallah ◽  
Rama Bhat ◽  
Wen-Fang Xie

The main focus of the present paper is on the design of a modified sky-hook control of a semi-active Macpherson suspension system by means of H∞ Output Feedback Control (OFC) theory. To this end, a new dynamic model, incorporating the kinematics of the suspension system, is used for the controller design. The combination of a Linear Matrix Inequality (LMI) solver and Genetic Algorithm (GA) is adopted to regulate the static output feedback control gain so that the stability conditions are fulfilled and control objectives are achieved. Meanwhile, a three-dimensional kinematic model of the system is incorporated to investigate the influence of the control force variation on the steering, handling and stability of the vehicle. A geometric relation of the vehicle roll center is employed to study one more extra aspect of the comfort and stability of the vehicle. The results show that the proposed controller improves the kinematic and dynamic performances of the suspension well compared with those of the passive system. Moreover, it is concluded that a superior stability of the vehicle during the cornering can be achieved by adjusting the height of the vehicle roll center passively so that the stability of the vehicle is improved while the forward motion specifications can be modified by an appropriate suspension control design.


2016 ◽  
Vol 2016 ◽  
pp. 1-13
Author(s):  
Luo Zhang ◽  
Mou Chen ◽  
Qingxian Wu ◽  
Bei Wu

The problem of state feedback stabilization is studied for networked control systems (NCSs) subject to actuator saturation and network-induced delays. To facilitate the controller design, the NCSs are modeled as a class of discrete-time systems with bounded delays and input saturation. Based on Lyapunov-Krasovskii theory and free weighting matrix approach, the sufficient condition is derived in terms of linear matrix inequality for the asymptotic stability. Finally, the effectiveness of the developed control approach is proved through numerical examples.


2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Shou-Tao Peng

This paper studies the practical stability of incorporating integral compensation into the original low-and-high gain feedback law. The motivation for the incorporation is for achieving output regulation in the presence of constant disturbances without the use of a very large high-gain parameter required in the original approach. Due to numerical accuracy, the employment of very large high-gain parameters to eliminate steady-state error has the potential for inducing undesirable chattering effect on the control signal. A set of linear matrix inequalities is formulated in this study to obtain the related design parameters, by which the incorporation can achieve both the practical stabilization and asymptotic output regulation in the presence of input saturation and constant disturbances. Furthermore, the saturation of the control input can be shown to vanish in finite time during the process of regulation. Numerical examples are given to demonstrate the effectiveness of the proposed approach.


2017 ◽  
Vol 40 (8) ◽  
pp. 2526-2535 ◽  
Author(s):  
S Mohammadpour ◽  
T Binazadeh

This paper considers the synchronization between two chaotic systems (i.e. master and slave systems) in the presence of practical constraints. The considered constraints are: the unavailability of state variables of both master and slave system, the presence of non-symmetric input saturation, model uncertainties and/or external disturbances (matched and/or unmatched). Considering these constraints, an adaptive robust observer-based controller is designed, which guarantees synchronization between the chaotic systems. For this purpose, a theorem is given and, according to a Lyapunov adaptive stabilization approach, it is proved that the robust synchronization via the proposed observer-based controller is guaranteed in the presence of actuator saturation and it is shown that even if the control signal is saturated, the proposed controller leads to a robust synchronization objective. Finally, in order to show the applicability of the proposed controller, it is applied on the Van der Pol chaotic systems. Computer simulations verify the theoretical results and show the effective performance of the proposed controller.


2019 ◽  
Vol 41 (16) ◽  
pp. 4511-4520
Author(s):  
Yan Jiang ◽  
Junyong Zhai

This paper aims at addressing the sampled-data output feedback control problem for a class of uncertain switched stochastic nonlinear systems, whose control input is quantized by a logarithmic quantizer and the output gain cannot be precisely known. We design a compensator with the quantized information. With the help of the feedback domination approach and the backstepping design method, a sampled-data output feedback controller is constructed with appropriate design parameters and a maximum sampling period to guarantee the global exponential stability in mean square of the closed-loop system under arbitrary switching. Finally, a numerical example is given to illustrate the effectiveness of the proposed scheme.


2020 ◽  
Vol 34 (35) ◽  
pp. 2050409
Author(s):  
Youguo He ◽  
Xiaoxiao Tian ◽  
Jie Shen ◽  
Chaochun Yuan ◽  
Yingkui Du

This paper is concerned with the problem of constraint control for cooperative adaptive cruise control (CACC) with input saturation and input-additive uncertainties. An integrated longitudinal kinematic model of CACC system including vehicle model and constant time headway is established taking into account input saturation and input-additive uncertainties. According to the system’s robustness requirements under input saturation, the saturation control method is introduced. In order to achieve robust global stabilization of the system, a low-gain state feedback control law is designed by using linear low-gain feedback and gain scheduling. Meanwhile, in order to avoid the saturation of the control system, the low gain parameter [Formula: see text] is introduced into the controller design. Finally, the simulation of homogeneous and heterogeneous platoons is carried out by MATLAB/Simulink, which verifies the feasibility and effectiveness of the designed controller. Compared with the SMC controller, saturation controller successfully suppresses the acceleration amplification in the process of propagation along the vehicle platoon, avoids actuator saturation and realizes the stability of CACC system.


Symmetry ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 375
Author(s):  
Hejun Yao

The problem of anti-saturation control for a class of time-delay systems with actuator saturation is considered in this paper. By introducing appropriate variable substitution, a new delay time-delay systems model with actuator saturation systems is established. Based on the Lyapunov stability theory, the stability condition and the anti-saturation controller design method are obtained by using the linear matrix inequality approach. By introducing the matrix into the Lyapunov function, the proposed conditions are less conservative than the previous results. Finally, a simulation example shows the validity and rationality of the method.


Author(s):  
Kyoungchul Kong ◽  
Helge C. Kniep ◽  
Masayoshi Tomizuka

Input saturation is a well-known nonlinearity in mechanical control systems; it constrains the maximum acceleration, which results in the limitation of the system response time. Input saturation has been considered in controller design in various ways, e.g., antiwindup control. In addition to the input, the state variables of mechanical systems are often subjected to saturation. For example, the maximum angular velocity of electric motor systems is limited by the maximum voltage provided to the motor windings. In the case of electronically commutated motors (i.e., brushless dc motors), the maximum speed is additionally constrained by limitations of the servo amplifier output. If gears are utilized, further constraints are introduced due to resonances in ball bearings and/or velocity dependent friction. Although such factors are significant in practice, they have not been fully considered in controller design. This paper investigates the input and output saturations, and presents how they may be considered in the controller design; a Kalman filter, a PID controller, and a disturbance observer are designed, taking input/output saturations into consideration. A case study is provided to verify the proposed methods.


2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Faguang Wang ◽  
Hongmei Wang ◽  
Yong Zhang ◽  
Xijin Guo

A minimally invasive surgery robot is difficult to control when actuator saturation exists. In this paper, a Takagi-Sugeno fuzzy model-based controller is designed for a minimally invasive surgery robot with actuator saturation, which is difficult to control. The contractively invariant ellipsoid theorem is applied for the actuator saturation. The proposed scheme can be derived using the H-infinity control theorem and parallel distributed compensation. The result is rebuilt in the form of linear matrix inequalities for easier calculation by computer. Meanwhile, the uniformly ultimately bounded stable and the prescribed H-infinity control performance can be guaranteed. The proposed scheme is simulated in a Novint Falcon haptic device system.


2012 ◽  
Vol 189 ◽  
pp. 364-368
Author(s):  
Zhao Yuan Wang ◽  
Guo Qing Wu

The magnetic suspension system is a strong nonlinear, uncertain and open-loop unstable system. All of these factors have increased the difficulty of maglev controller design. Considering the single freedom maglev system as the research object in this paper, structure analysis and modeling design are conducted for the system. By choosing new state variables, the system model is transformed. On the basis of that, we use back stepping design method to design the nonlinear suspension controller. Control performance of the controller can be observed by the Matlab/Simulink simulation.


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