Parameter-Varying Loop-Shaping for Delayed Air-Fuel Ratio Control in Lean-Burn SI Engines

Author(s):  
Shahin Tasoujian ◽  
Behrouz Ebrahimi ◽  
Karolos Grigoriadis ◽  
Matthew Franchek

Dynamic systems with time-varying delay in the control input are studied in the present paper. The delay is considered as a varying parameter and Padé approximation is applied to transfer the infinite-dimensional delay problem into a finite-dimensional paradigm represented in the form of a non-minimum phase system (NMP). Inherited delay characteristics are now represented through unstable internal dynamics for the NMP system, which poses restrictions on the achievable control bandwidth thereby resulting in an imperfect tracking performance and poor stability condition. Presented in this paper, is a methodical parameter-varying loop-shaping control design approach, which simultaneously satisfy a variety of control requirements and offer an insight into the limitations posed by the NMP representation. The suggested method is then applied to fueling control in lean-burn gasoline engines addressing the varying transport and combustion delay. The developed approach is validated with experimental data on a Ford F-150 truck SI lean-burn engine with large time-varying delay in the control loop and the closed-loop system responses are presented to demonstrate disturbance rejection, measurement noise attenuation, and robustness properties against delay estimation errors.

Author(s):  
Shenquan Wang ◽  
Wenchengyu Ji ◽  
Yulian Jiang ◽  
Keping Liu

Considering two types of delays including both time-varying delay and parameter varying delay in continuous switched linear parameter varying systems, the problem of [Formula: see text] filtering under average dwell time switching is illustrated. The [Formula: see text] filter depending on the linear time-varying parameter [Formula: see text] (mode-dependent parameterized filter) is designed at first. Then, based on multiple Lyapunov function and an improved reciprocally convex inequality, the corresponding existence sufficient conditions for the filter could ensure the obtained filter error system exponentially stable with a guaranteed [Formula: see text] performance in the form of linear matrix inequalities. In addition, the designed filter gains under allowed switching signals are computed via the proposed convex optimal algorithm. In the end, two numerical examples show the effectiveness of the results in this work.


Author(s):  
Jun-Wei Wang ◽  
Chang-Yin Sun

This paper extends the framework of Lyapunov–Krasovskii functional to address the problem of exponential stabilization for a class of linearly distributed parameter systems (DPSs) with continuous differentiable time-varying delay and a spatiotemporal control input, where the system model is described by parabolic partial differential-difference equations (PDdEs) subject to homogeneous Neumann or Dirichlet boundary conditions. By constructing an appropriate Lyapunov–Krasovskii functional candidate and using some inequality techniques (e.g., spatial integral form of Jensen's inequalities and vector-valued Wirtinger's inequalities), some delay-dependent exponential stabilization conditions are derived, and presented in terms of standard linear matrix inequalities (LMIs). These stabilization conditions are applicable to both slow-varying and fast-varying time delay cases. The detailed and rigorous proof of the closed-loop exponential stability is also provided in this paper. Moreover, the main results of this paper are reduced to the constant time delay case and extended to the stochastic time-varying delay case, and also extended to address the problem of exponential stabilization for linear parabolic PDdE systems with a temporal control input. The numerical simulation results of two examples show the effectiveness and merit of the main results.


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Lulu Feng ◽  
Ping Zhao

This paper deals with the finite-time stability (FTS) of switched linear time-varying (SLTV) systems with time-varying delay. Firstly, based on Lyapunov–Krasovskii functional technique and average dwell time (ADT) approach, a sufficient criterion on FTS for SLTV systems with time-varying delay is obtained. For the SLTV system with delay and control input, based on the criterion, a state feedback controller is designed such that the closed-loop system is finite-time stable (FTS). Finally, an example is employed to illustrate the validity of our results.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Sung Wook Yun ◽  
Sung Hyun Kim

This paper aims at deriving an efficient criterion for the robust stability analysis of discrete-time systems with time-varying delay. In the derivation, to obtain a larger stability region under the requirement of less computational complexity, this paper proposes a valuable method capable of establishing a less conservative stability criterion without using the free-weighting approach and an extremely augmented state. In parallel, the stabilization problem of systems with time-delayed control input is addressed in connection with the derived stability criterion.


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