Electrical and Electronic Engineering - Research Publications

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    Sub-Optimal Moving Horizon Estimation in Feedback Control of Linear Constrained Systems
    Yang, Y ; Manzie, C ; Pu, Y (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2023)
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    Reachability of Linear Time-Invariant Systems via Ellipsoidal Approximations
    Liu, V ; Manzie, C ; Dower, PM (Elsevier BV, 2023-01-01)
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    TRACKING AND REGRET BOUNDS FOR ONLINE ZEROTH-ORDER EUCLIDEAN AND RIEMANNIAN OPTIMIZATION
    Maass, A ; Manzie, C ; Nesic, D ; Manton, JH ; Shames, I (SIAM PUBLICATIONS, 2022)
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    Sub-Optimal MPC With Dynamic Constraint Tightening
    Yang, Y ; Wang, Y ; Manzie, C ; Pu, Y (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2023)
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    An algorithm for the selection of linearisation points in non-linear systems: a diesel air-path case study
    Ahmadizadeh, S ; Maass, A ; Manzie, C ; Shames, I (TAYLOR & FRANCIS LTD, 2023-12-02)
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    Online optimization of spark advance in alternative fueled engines using extremum seeking control
    Mohammadi, A ; Manzie, C ; Nesic, D (Elsevier, 2014-08-01)
    Alternative fueled engines offer greater challenges for engine control courtesy of uncertain fuel composition. This makes optimal tuning of input parameters like spark advance extremely difficult in most existing ECU architectures. This paper proposes the use of grey-box extremum seeking techniques to provide real-time optimization of the spark advance in alternative fueled engines. Since practical implementation of grey-box extremum seeking methods is typically done using digital technology, this paper takes advantage of emulation design methods to port the existing continuous-time grey-box extremum seeking methods to discrete-time frameworks. The ability and flexibility of the proposed discrete-time framework is demonstrated through simulations and in practical situation using a natural gas fueled engine.
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    Multi-agent source seeking via discrete-time extremum seeking control
    Khong, SZ ; Tan, Y ; Manzie, C ; Nesic, D (PERGAMON-ELSEVIER SCIENCE LTD, 2014-09)
    Recent developments in extremum seeking theory have established a general framework for the methodology, although the specific implementations, particularly in the context of multi-agent systems, have not been demonstrated. In this work, a group of sensor-enabled vehicles is used in the context of the extremum seeking problem using both local and global optimisation algorithms to locate the extremum of an unknown scalar field distribution. For the former, the extremum seeker exploits estimates of gradients of the field from local dithering sensor measurements collected by the mobile agents. It is assumed that a distributed coordination which ensures uniform asymptotic stability with respect to a prescribed formation of the agents is employed. An inherent advantage of the frameworks is that a broad range of nonlinear programming algorithms can be combined with a wide class of cooperative control laws to perform extreme source seeking. Semi-global practical asymptotically stable convergence to local extrema is established in the presence of field sampling noise. Subsequently, global extremum seeking with multiple agents is investigated and shown to give rise to robust practical convergence whose speed can be improved via computational parallelism. Nonconvex field distributions with local extrema can be accommodated within this global framework.
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    Extremum seeking of dynamical systems via gradient descent and stochastic approximation methods
    Khong, SZ ; Tan, Y ; Manzie, C ; Nesic, D (Elsevier, 2015-06)
    Abstract This paper examines the use of gradient based methods for extremum seeking control of possibly infinite-dimensional dynamic nonlinear systems with general attractors within a periodic sampled-data framework. First, discrete-time gradient descent method is considered and semi-global practical asymptotic stability with respect to an ultimate bound is shown. Next, under the more complicated setting where the sampled measurements of the plant’s output are corrupted by an additive noise, three basic stochastic approximation methods are analysed; namely finite-difference, random directions, and simultaneous perturbation. Semi-global convergence to an optimum with probability one is established. A tuning parameter within the sampled-data framework is the period of the synchronised sampler and hold device, which is also the waiting time during which the system dynamics settle to within a controllable neighbourhood of the steady-state input–output behaviour.
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    Multi-time-scale observer design for state-of-charge and state-of-health of a lithium-ion battery
    Zou, C ; Manzie, C ; Nesic, D ; Kallapur, AG (ELSEVIER SCIENCE BV, 2016-12-15)
    The accurate online state estimation for some types of nonlinear singularly perturbed systems is challenging due to extensive computational requirements, ill-conditioned gains and/or convergence issues. This paper proposes a multi-time-scale estimation algorithm for a class of nonlinear systems with coupled fast and slow dynamics. Based on a boundary-layer model and a reduced model, a multi-time-scale estimator is proposed in which the design parameter sets can be tuned in different time-scales. Stability property of the estimation errors is analytically characterized by adopting a deterministic version of extended Kalman filter (EKF). This proposed algorithm is applied to estimator design for the state-of-charge (SOC) and state-of-health (SOH) in a lithium-ion battery using the developed reduced order battery models. Simulation results on a high fidelity lithium-ion battery model demonstrate that the observer is effective in estimating SOC and SOH despite a range of common errors due to model order reductions, linearisation, initialisation and noisy measurement.
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    Model Predictive Control for Lithium-Ion Battery Optimal Charging
    Zou, C ; Manzie, C ; Nesic, D (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2018-04)
    Charging time and lifetime are important performances for lithium-ion (Li-ion) batteries, but are often competing objectives for charging operations. Model-based charging controls are challenging due to the complicated battery system structure that is composed of nonlinear partial differential equations and exhibits multiple time-scales. This paper proposes a new methodology for battery charging control enabling an optimal tradeoff between the charging time and battery state-of-health (SOH). Using recently developed model reduction approaches, a physics-based low-order battery model is first proposed and used to formulate a model-based charging strategy. The optimal fast charging problem is formulated in the framework of tracking model predictive control (MPC). This directly considers the tracking performance for provided state-of-charge and SOH references, and explicitly addresses constraints imposed on input current and battery internal state. The capability of this proposed charging strategy is demonstrated via simulations to be effective in tracking the desirable SOH trajectories. By comparing with the constant-current constant-voltage charging protocol, the MPC-based charging appears promising in terms of both the charging time and SOH. In addition, this obtained charging strategy is practical for real-time implementation.