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Seungbok Choi - One of the best experts on this subject based on the ideXlab platform.
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response time of magnetorheological dampers to current inputs in a semi active Suspension system Modeling control and sensitivity analysis
Mechanical Systems and Signal Processing, 2021Co-Authors: Dalseong Yoon, Giwoo Kim, Seungbok ChoiAbstract:Abstract A new magnetorheological (MR) damper has been recently developed that delivers a very fast response to the input current (or magnetic field). This study investigates the effect of the MR-damper response time on the vibration control of a full-car semi-active Suspension system subjected to parameter uncertainties. After briefly reviewing the response-time characteristics of the fast-response MR damper, a full-car Suspension Model with seven degrees of freedom (DOF) is derived by considering the time constant of the actuator. Subsequently, a robust sliding mode controller is formulated for achieving effective vibration control of the Suspension system for three different motions: heave, pitch, and roll. For the synthesis of the controller, the sprung mass is considered the uncertain parameter, and the stability of the overall control system is proved via Lyapunov stability. By evaluating the performance at a random road profile, it is shown that both ride comfort and road holding (steering stability) can be enhanced by utilizing the fast-response MR damper. In addition, to analyze the control results, the nonlinear Suspension Model is linearized. Using the linearized Model, the state outputs from the road input are observed, and the sensitivities of the closed loop feedback system considering response time of MR dampers are analyzed in the Nyquist domain.
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an adaptive fuzzy sliding mode control of magneto rheological seat Suspension with human body Model
Journal of Intelligent Material Systems and Structures, 2016Co-Authors: Do Kyun Shin, Do Xuan Phu, Sangmin Choi, Seungbok ChoiAbstract:This article presents the control performances of a vehicle seat Suspension system equipped with magneto-rheological dampers using a new adaptive fuzzy sliding mode controller. A magneto-rheological damper is designed by applying the Bingham Model incorporating with the field-dependent rheological properties of magneto-rheological fluid. On the other hand, a seat Suspension Model is established by integrating with a 4-degree-of-freedom human body Model. Then, the governing equations are then derived considering the vertical motion of the seat. Subsequently, an adaptive fuzzy controller is formulated by considering the acceleration of the seat. This controller is combined with the sliding mode controller to ensure the robustness against Model uncertainty and external disturbances. The controller is then evaluated through experiment. It is demonstrated that the proposed seat Suspension system realized by the proposed adaptive fuzzy sliding mode controller can provide very effective ride comfort performances...
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vibration control of an mr vehicle Suspension system considering both hysteretic behavior and parameter variation
Smart Materials and Structures, 2009Co-Authors: Seungbok Choi, Minsang Seong, Sunghoon HaAbstract:This paper presents vibration control responses of a controllable magnetorheological (MR) Suspension system considering the two most important characteristics of the system; the field-dependent hysteretic behavior of the MR damper and the parameter variation of the Suspension. In order to achieve this goal, a cylindrical MR damper which is applicable to a middle-sized passenger car is designed and manufactured. After verifying the damping force controllability, the field-dependent hysteretic behavior of the MR damper is identified using the Preisach hysteresis Model. The full-vehicle Suspension Model is then derived by considering vertical, pitch and roll motions. An controller is designed by treating the sprung mass of the vehicle as a parameter variation and integrating it with the hysteretic compensator which produces additional control input. In order to demonstrate the effectiveness and robustness of the proposed control system, the hardware-in-the-loop simulation (HILS) methodology is adopted by integrating the Suspension Model with the proposed MR damper. Vibration control responses of the vehicle Suspension system such as vertical acceleration are evaluated under both bump and random road conditions.
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vibration control of an electrorheological fluid based Suspension system with an energy regenerative mechanism
Proceedings of the Institution of Mechanical Engineers Part D: Journal of Automobile Engineering, 2009Co-Authors: Seungbok Choi, Minsang Seong, K S KimAbstract:AbstractThis work presents vibration control of a vehicle Suspension system using a controllable electrorheological (ER) shock absorber activated by an energy generator without external power sources. The ER shock absorber has a rack and pinion mechanism which converts a linear motion of the piston to a rotary motion. This rotary motion is amplified by gears and subsequently activates a generator to produce electrical energy. The generated voltage is experimentally evaluated with respect to excitation magnitude and frequency of the ER shock absorber. After evaluating the damping force using the regenerated voltage, a quarter-car ER Suspension Model is established. A skyhook controller is then formulated and experimentally implemented to attenuate vibration using the regenerated energy. It has been demonstrated via experiment that Suspension vibration under bumpy and sinusoidal road conditions is significantly controlled by activating the ER shock absorber operated by the proposed regenerative energy mecha...
Nong Zhang - One of the best experts on this subject based on the ideXlab platform.
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Integrated Seat and Suspension Control for a Quarter Car With Driver Model
IEEE Transactions on Vehicular Technology, 2012Co-Authors: Haiping Du, Weihua Li, Nong ZhangAbstract:In this paper, an integrated vehicle seat and Suspension control strategy for a quarter car with driver Model is proposed to improve Suspension performance on driver ride comfort. An integrated seat and Suspension Model that includes a quarter-car Suspension, a seat Suspension, and a 4-degree-of-freedom (DOF) driver body Model is presented first. This integrated Model provides a platform to evaluate ride comfort performance in terms of driver head acceleration responses under typical road disturbances and to develop an integrated control of seat and car Suspensions. Based on the integrated Model, an H∞ state feedback controller is designed to minimize the driver head acceleration under road disturbances. Considering that state variables for a driver body Model are not measurement available in practice, a static output feedback controller, which only uses measurable state variables, is designed. Further discussion on robust multiobjective controller design, which considers driver body parameter uncertainties, Suspension stroke limitation, and road-holding properties, is also provided. Last, numerical simulations are conducted to evaluate the effectiveness of the proposed control strategy. The results show that the integrated seat and Suspension control can effectively improve Suspension ride comfort performance compared with the passive seat Suspension, active seat Suspension control, and active car Suspension control.
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semi active variable stiffness vibration control of vehicle seat Suspension using an mr elastomer isolator
Smart Materials and Structures, 2011Co-Authors: Haiping Du, Weihua Li, Nong ZhangAbstract:This paper presents a study on continuously variable stiffness control of vehicle seat Suspension using a magnetorheological elastomer (MRE) isolator. A concept design for an MRE isolator is proposed in the paper and its behavior is experimentally evaluated. An integrated seat Suspension Model, which includes a quarter-car Suspension and a seat Suspension with a driver body Model, is used to design a sub-optimal controller for an active isolator. The desired control force generated by this active isolator is then emulated by the MRE isolator through its continuously variable stiffness property when the actuating condition is met. The vibration control effect of the MRE isolator is evaluated in terms of driver body acceleration responses under both bump and random road conditions. The results show that the proposed control strategy achieves better vibration reduction performance than conventional on–off control.
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fuzzy control for nonlinear uncertain electrohydraulic active Suspensions with input constraint
IEEE Transactions on Fuzzy Systems, 2009Co-Authors: Nong ZhangAbstract:This paper presents a Takagi-Sugeno (T-S) Model-based fuzzy control design approach for electrohydraulic active vehicle Suspensions considering nonlinear dynamics of the actuator, sprung mass variation, and constraints on the control input. The T-S fuzzy Model is first applied to represent the nonlinear uncertain electrohydraulic Suspension. Then, a fuzzy state feedback controller is designed for the obtained T-S fuzzy Model with optimized H infin performance for ride comfort by using the parallel-distributed compensation (PDC) scheme. The sufficient conditions for the existence of such a controller are derived in terms of linear matrix inequalities (LMIs). Numerical simulations on a full-car Suspension Model are performed to validate the effectiveness of the proposed approach. The obtained results show that the designed controller can achieve good Suspension performance despite the existence of nonlinear actuator dynamics, sprung mass variation, and control input constraints.
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parameter dependent input delayed control of uncertain vehicle Suspensions
Journal of Sound and Vibration, 2008Co-Authors: Nong ZhangAbstract:This paper presents a parameter-dependent controller design approach for vehicle active Suspensions to deal with changes in vehicle inertial properties and existence of actuator time delays. By defining a parameter-dependent Lyapunov functional, matrix inequality conditions with reduced conservatism are obtained for the design of controllers. Feasible solutions can be obtained by solving a finite number of linear matrix inequalities (LMIs) embedded within a genetic algorithm (GA). Both state feedback and static output feedback controllers can be designed under a unified framework. Based on the measurement or estimation of the vehicle inertial parameters, a parameter-dependent controller could be implemented in practice. The presented approach is applied to a two-degree-of-freedom quarter-car Suspension Model. Numerical simulations on both bump and random road responses show that the designed parameter-dependent controllers can achieve good active Suspension performance regardless of the variation on the sprung mass and the presence of actuator time delay.
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constrained h control of active Suspension for a half car Model with a time delay in control
Proceedings of the Institution of Mechanical Engineers Part D: Journal of Automobile Engineering, 2008Co-Authors: Nong ZhangAbstract:AbstractThe paper presents a new controller design approach for a four-degrees-of-freedom half-car Suspension Model considering the time delay in the control input. The time delay for the control input is assumed to be uncertain time invariant within a known constant bound. The ride comfort performance of the Suspension system is optimized by using the H∞ norm to measure the body accelerations (including both the heaving and the pitching motions), while the tyre deflections and the Suspension rattle spaces are constrained by their peak response values in time domain using the generalized H2 (GH2) norm (energy-to-peak) performance. Then, a constrained delay-dependent H∞ state feedback controller is designed to realize the ride comfort, road holding and stroke limitation performance to prescribed level in spite of the existence of a time delay in control input. The design approach is formulated in terms of the feasibility of certain delay-dependent matrix inequalities. A numerical example is used to illustr...
H Liu - One of the best experts on this subject based on the ideXlab platform.
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adaptive sliding mode control for nonlinear active Suspension vehicle systems using t s fuzzy approach
IEEE Transactions on Industrial Electronics, 2013Co-Authors: Chris Hilton, H LiuAbstract:This paper deals with the adaptive sliding-mode control problem for nonlinear active Suspension systems via the Takagi-Sugeno (T-S) fuzzy approach. The varying sprung and unsprung masses, the unknown actuator nonlinearity, and the Suspension performances are taken into account simultaneously, and the corresponding mathematical Model is established. The T-S fuzzy system is used to describe the original nonlinear system for the control-design aim via the sector nonlinearity approach. A sufficient condition is proposed for the asymptotical stability of the designing sliding motion. An adaptive sliding-mode controller is designed to guarantee the reachability of the specified switching surface. The condition can be converted to the convex optimization problems. Simulation results for a half-vehicle active Suspension Model are provided to demonstrate the effectiveness of the proposed control schemes.
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reliable fuzzy control for active Suspension systems with actuator delay and fault
IEEE Transactions on Fuzzy Systems, 2012Co-Authors: H Liu, Huijun Gao, Peng ShiAbstract:This paper is focused on reliable fuzzy H∞ controller design for active Suspension systems with actuator delay and fault. The Takagi-Sugeno (T-S) fuzzy Model approach is adapted in this study with the consideration of the sprung and the unsprung mass variation, the actuator delay and fault, and other Suspension performances. By the utilization of the parallel-distributed compensation scheme, a reliable fuzzy H∞ performance analysis criterion is derived for the proposed T-S fuzzy Model. Then, a reliable fuzzy H∞ controller is designed such that the resulting T-S fuzzy system is reliable in the sense that it is asymptotically stable and has the prescribed H∞ performance under given constraints. The existence condition of the reliable fuzzy H∞ controller is obtained in terms of linear matrix inequalities (LMIs) Finally, a quarter- vehicle Suspension Model is used to demonstrate the effectiveness and potential of the proposed design techniques.
David Brown - One of the best experts on this subject based on the ideXlab platform.
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adaptive fuzzy controller for vehicle active Suspensions with particle swarm optimization
Seventh International Symposium on Instrumentation and Control Technology: Optoelectronic Technology and Instruments Control Theory and Automation and, 2008Co-Authors: Ping Li, David BrownAbstract:With the particle swarm optimal (PSO) algorithm, an adaptive fuzzy logic controller (AFC) based on interval fuzzy membership functions is proposed for vehicle non-linear active Suspension systems. The interval membership functions (IMFs) are utilized in the AFC design to deal with not only non-linearity and uncertainty caused from irregular road inputs and immeasurable disturbance, but also the potential uncertainty of expert's knowledge and experience. The adaptive strategy is designed to self-tune the active force between the lower bounds and upper bounds of interval fuzzy outputs. A case study based on a quarter active Suspension Model has demonstrated that the proposed adaptive fuzzy controller significantly outperforms conventional fuzzy controllers of an active Suspension and a passive Suspension.
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an interval type 2 fuzzy logic controller for quarter vehicle active Suspensions
Proceedings of the Institution of Mechanical Engineers Part D: Journal of Automobile Engineering, 2008Co-Authors: Ping Li, David BrownAbstract:A novel adaptive fuzzy logic controller (AFC) based on an interval type-2 fuzzy controller is proposed for vehicle non-linear active Suspension systems. The adaptive strategy elicited from the least-mean-squares optimal algorithm is adopted to self-tune lower bounds and upper bounds of interval type-2 fuzzy membership functions (IMF2s). The IMF2s are utilized in the AFC design to deal with not only non-linearity and uncertainty caused by irregular road inputs and immeasurable disturbance, but also the potential uncertainty of experts knowledge and experience. A case study based on a quarter-vehicle active Suspension Model has demonstrated that the proposed type-2 controller significantly outperforms conventional fuzzy controllers of an active Suspension and a passive Suspension.
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adaptive fuzzy logic controller for vehicle active Suspensions with interval type 2 fuzzy membership functions
IEEE International Conference on Fuzzy Systems, 2008Co-Authors: Ping Li, David BrownAbstract:Elicited from the least means squares optimal algorithm (LMS), an adaptive fuzzy logic controller (AFC) based on interval type-2 fuzzy sets is proposed for vehicle non-linear active Suspension systems. The interval membership functions (IMF2s) are utilized in the AFC design to deal with not only non-linearity and uncertainty caused from irregular road inputs and immeasurable disturbance, but also the potential uncertainty of expertpsilas knowledge and experience. The adaptive strategy is designed to self-tune the active force between the lower bounds and upper bounds of interval fuzzy outputs. A case study based on a quarter active Suspension Model has demonstrated that the proposed type-2 fuzzy controller significantly outperforms conventional fuzzy controllers of an active Suspension and a passive Suspension.
Haiping Du - One of the best experts on this subject based on the ideXlab platform.
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Integrated Seat and Suspension Control for a Quarter Car With Driver Model
IEEE Transactions on Vehicular Technology, 2012Co-Authors: Haiping Du, Weihua Li, Nong ZhangAbstract:In this paper, an integrated vehicle seat and Suspension control strategy for a quarter car with driver Model is proposed to improve Suspension performance on driver ride comfort. An integrated seat and Suspension Model that includes a quarter-car Suspension, a seat Suspension, and a 4-degree-of-freedom (DOF) driver body Model is presented first. This integrated Model provides a platform to evaluate ride comfort performance in terms of driver head acceleration responses under typical road disturbances and to develop an integrated control of seat and car Suspensions. Based on the integrated Model, an H∞ state feedback controller is designed to minimize the driver head acceleration under road disturbances. Considering that state variables for a driver body Model are not measurement available in practice, a static output feedback controller, which only uses measurable state variables, is designed. Further discussion on robust multiobjective controller design, which considers driver body parameter uncertainties, Suspension stroke limitation, and road-holding properties, is also provided. Last, numerical simulations are conducted to evaluate the effectiveness of the proposed control strategy. The results show that the integrated seat and Suspension control can effectively improve Suspension ride comfort performance compared with the passive seat Suspension, active seat Suspension control, and active car Suspension control.
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semi active variable stiffness vibration control of vehicle seat Suspension using an mr elastomer isolator
Smart Materials and Structures, 2011Co-Authors: Haiping Du, Weihua Li, Nong ZhangAbstract:This paper presents a study on continuously variable stiffness control of vehicle seat Suspension using a magnetorheological elastomer (MRE) isolator. A concept design for an MRE isolator is proposed in the paper and its behavior is experimentally evaluated. An integrated seat Suspension Model, which includes a quarter-car Suspension and a seat Suspension with a driver body Model, is used to design a sub-optimal controller for an active isolator. The desired control force generated by this active isolator is then emulated by the MRE isolator through its continuously variable stiffness property when the actuating condition is met. The vibration control effect of the MRE isolator is evaluated in terms of driver body acceleration responses under both bump and random road conditions. The results show that the proposed control strategy achieves better vibration reduction performance than conventional on–off control.
