state and parameterestimation methodologies have the potential to make a significant impact in the development of broad array of capabilities for widely-used vapor compression cycles, including advanced controls, per...
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ISBN:
(纸本)9781713872344
state and parameterestimation methodologies have the potential to make a significant impact in the development of broad array of capabilities for widely-used vapor compression cycles, including advanced controls, performance monitoring, data-driven modeling, and deployment of digital twin technologies. However, the nonlinearity and numerical stiffness of large physics-based models of these systems pose challenges for the practical implementation of estimators that must also satisfy the physical state constraints. We present a three-pass fixed-interval smoothing method developed in the extended Kalman estimation formalism that incorporates linear inequality and partially-known nonlinear equality constraints defined in terms of unknown parameters of the system. The smoothing method is demonstrated to have high estimation accuracy during joint state and parameterestimation of the cycle model representing a realistic system that is implemented in Julia language leveraging automatic differentiation capabilities. Copyright (C) 2023 The Authors.
state and parameterestimation methodologies have the potential to make a significant impact in the development of broad array of capabilities for widely-used vapor compression cycles, including advanced controls, per...
详细信息
state and parameterestimation methodologies have the potential to make a significant impact in the development of broad array of capabilities for widely-used vapor compression cycles, including advanced controls, performance monitoring, data-driven modeling, and deployment of digital twin technologies. However, the nonlinearity and numerical stiffness of large physics-based models of these systems pose challenges for the practical implementation of estimators that must also satisfy the physical state constraints. We present a three-pass fixed-interval smoothing method developed in the extended Kalman estimation formalism that incorporates linear inequality and partially-known nonlinear equality constraints defined in terms of unknown parameters of the system. The smoothing method is demonstrated to have high estimation accuracy during joint state and parameterestimation of the cycle model representing a realistic system that is implemented in Julia language leveraging automatic differentiation capabilities.
Novel drivetrain concepts such as electric direct drives can improve vehicle dynamic control due to faster, more accurate, and more flexible generation of wheel individual propulsion and braking torques. Exact and rob...
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Novel drivetrain concepts such as electric direct drives can improve vehicle dynamic control due to faster, more accurate, and more flexible generation of wheel individual propulsion and braking torques. Exact and robust estimation of vehicle state of motion in the presence of unknown disturbances, such as changes in road conditions, is crucial for realization of such control systems. This article shows the design, tuning, implementation, and test of a state estimator with individual tire model adaption for direct drive electric vehicles. The vehicle dynamics are modeled using a double-track model with an adaptive tire model. state-of-the-art sensors, an inertial measurement unit, steering angle, wheel speed, and motor current sensors are used as measurements. Due to the nonlinearity of the vehicle model, an Unscented Kalman Filter (UKF) is used for simultaneous state and parameterestimation. To simplify the difficult task of UKF tuning, an optimization-based method using real-vehicle data is utilized. The UKF is implemented on an electronic control unit and tested with real-vehicle data in a hardware-in-the-loop simulation. High precision even in severe driving maneuvers under various road conditions is achieved. nonlinear state and parameter estimation for all wheel drive electric vehicles using UKF and optimization-based tuning is shown to provide high precision with minimal manual tuning effort.
Moving horizon estimation (MHE) solves a constrained dynamic optimisation problem. Including nonlinear dynamics into an optimal estimation problem generally comes at the cost of tackling a non-convex optimisation prob...
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Moving horizon estimation (MHE) solves a constrained dynamic optimisation problem. Including nonlinear dynamics into an optimal estimation problem generally comes at the cost of tackling a non-convex optimisation problem. Here, a particular model formulation is proposed in order to convexify a class of nonlinear MHE problems. It delivers a linear time-varying (LTV) model that is globally equivalent to the nonlinear dynamics in a noise-free environment, hence the optimisation problem becomes convex. On the other hand, in the presence of unknown disturbances, the accuracy of the LTV model degrades and this results in a less accurate solution. For this purpose, some assumptions are imposed and a homotopy-based approach is proposed in order to transform the problem from convex to non-convex, where the sequential implementation of this technique starts with solving the convexified MHE problem. Two simulation studies validate the efficiency and optimality of the proposed approach with unknown disturbances.
This paper addresses the problem of Oscillatory Failure Cases (OFC) detection in the Electrical Flight Control System (EFCS) of the Airbus airplanes. OFC can lead to strong interactions with loads and aero-elasticity ...
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This paper addresses the problem of Oscillatory Failure Cases (OFC) detection in the Electrical Flight Control System (EFCS) of the Airbus airplanes. OFC can lead to strong interactions with loads and aero-elasticity and consequently are to be detected very early. in time. The work describes the status of on going research activity undertaken within a collaborative project between Bordeaux University (France) and Airbus. An hydraulic actuator model is currently used as the basis for a robust analytical redundancy-based technique implemented in A380 Flight Control Computer (FCC) for detecting unauthorized oscillatory events. For upcoming and future generation aircraft (A/C), it could be required to detect OFC earlier with less important amplitude. The method presented here is based on nonlinearstate space modeling, associated with the same decision test as used by in-service Airbus A/C. It is shown that the model quality could be improved significantly by reliable estimating of some physical parameters. The fault indicating signals are compared on data set obtained from A380 computers during flight tests.
The goal of the article is to describe a software framework designed for nonlinearstateestimation of discrete time dynamic systems. The framework was designed with the aim to facilitate implementation, testing and u...
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The goal of the article is to describe a software framework designed for nonlinearstateestimation of discrete time dynamic systems. The framework was designed with the aim to facilitate implementation, testing and use of various nonlinearstateestimation methods in mind. The main strength of the framework is its versatility due to the possibility of either structural or probabilistic description of the problem. Besides the well-known basic nonlinearestimation methods such as the extended Kalman filter, the divided difference filters and the unscented Kalman filter, the framework implements particle filter with advanced features as well. As the framework is designed on the object oriented basis, further extension by user-specified nonlinearestimation algorithms is extremely easy. The paper provides a brief introduction into nonlinearstateestimation problem and describes the individual components of the framework, their key features and use. The strengths of the framework are presented in two examples.
The extended set-membership filter (ESMF) for nonlinear ellipsoidal estimation suffers from numerical instability. computation complexity as well as the difficulty in filter parameter selection. In this paper, a UD fa...
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The extended set-membership filter (ESMF) for nonlinear ellipsoidal estimation suffers from numerical instability. computation complexity as well as the difficulty in filter parameter selection. In this paper, a UD factorization-based adaptive set-membership filter is developed and applied to nonlinear joint estimation of both time-varying stales and parameters. As a result of using the proposed UD factorization, combined with a new sequential and selective measurement update strategy, the numerical stability and real-time applicability of conventional ESMF are substantially improved. Furthermore, an adaptive selection scheme of the filter parameters is derived to reduce the computation complexity and achieve sub-optimal estimation. Simulation results have shown the efficiency and robustness of the proposed method. Copyright (C) 2007 John Wiley & Sons, Ltd.
The aim of this paper is to present a software framework facilitating implementation, testing and use of various nonlinearestimation methods. This framework is designed to offer an easy to use tool for state estimati...
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The aim of this paper is to present a software framework facilitating implementation, testing and use of various nonlinearestimation methods. This framework is designed to offer an easy to use tool for stateestimation of discrete time dynamic stochastic systems. Besides implementation of various local and global stateestimation methods it contains procedures for system design and simulation. Its strength is in the fact that it provides means that help students get acquainted with nonlinearstateestimation problem and to be able to test features of various estimation methods. Another considerable advantage of proposed framework is its high modularity and extensibility. The paper briefly describes nonlinearestimation problem and its general solution using the Bayesian approach leading to the Bayesian recursive relations. Then it presents key features of the software framework designed in MATLAB environment that supports straightforward implementation of estimation methods based on the Bayesian approach. The strengths of the framework are demonstrated on implementation of the Divided difference filter 1st order.
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