Approximate dynamic programming for constrained linear systems: A piecewise quadratic approximation approach

Approximate dynamic programming (ADP) faces challenges in dealing with constraints in control problems. Model predictive control (MPC) is, in comparison, well-known for its accommodation of constraints and stability guarantees, although its computation is sometimes prohibitive. This paper introduces an approach combining the two methodologies...

Logic-based distributed switching control for agents in power-chained form with multiple unknown control directions

This work studies logic-based distributed switching control for nonlinear agents in power-chained form, where logic-based (switching) control arises from the online estimation of the control directions assumed to be unknown for all agents. Compared to the state-of-the-art logic-based mechanisms, the challenge of power-chained dynamics is that...

Coils’ Current Distortion Due to Variable Series Compensation Capacitance in EV Wireless Charging for a Constant Optimum Load

When considering EV wireless charging that uses inductive power transfer with magnetic resonance, the coils’ current distortion must be minimized to guarantee compliance with the electromagnetic compatibility limits on the radiated magnetic field set by the relevant industrial standards. This paper analyzes the current distortion caused by...

Finite-sample analysis of identification of switched linear systems with arbitrary or restricted switching

For the identification of switched systems with measured states and a measured switching signal, this work aims to analyze the effect of switching strategies on the estimation error. The data is assumed to be collected from globally asymptotically or marginally stable switched systems under switches that are arbitrary or subject to an average...

Excitation allocation for generic identifiability of linear dynamic networks with fixed modules

Identifiability of linear dynamic networks requires the presence of a sufficient number of external excitation signals. The problem of allocating a minimal number of external signals for guaranteeing generic network identifiability in the full measurement case has been recently addressed in the literature. Here we will extend that work by...

Continuous Reduced-Order Dynamic Model Based on Energy Balancing for Inductive Power Transfer Systems

Resonant circuits are commonly used in inductive power transfer (IPT) systems for the charging of electric vehicles because of the high power efficiency. Transient behaviors of the resonant circuits, which play a significant role in the design and analysis of IPT systems, are cumbersome to model analytically because of the high-order. This...

A Mode-Switching Based Phase Shift Control for Optimized Efficiency and Wide ZVS Operations in Wireless Power Transfer Systems

This article proposes a mode-switching-based phase shift control (MS-PSC) for wireless power transfer (WPT) systems, which is able to achieve power regulation, load matching, and wide ZVS operations simultaneously without using additional dc-dc converters. Based on the mode transitions between the full-bridge, mixed-bridge, and half-bridge...

Control strategies of CO₂ refrigeration / heat pump system for supermarkets

CO2 is a promising refrigerant compared to traditional HFCs due to its insignificant global warming potential and nonthreatening to the ozone layer. It has been used as refrigerant in industrial and commercial refrigeration in recent years. With high compactness and the ability to recover heat, CO2 booster systems have been widely installed in...

Frequency and amplitude stabilized terahertz quantum cascade laser as local oscillator

We demonstrate an experimental scheme to simultaneously stabilize the frequency and amplitude of a 3.5 THz third-order distributed feedback quantum cascade laser as a local oscillator. The frequency stabilization has been realized using a methanol absorption line, a power detector, and a proportional-integral-derivative (PID) loop. The amplitude...

Frequency locking of single-mode 3.5-THz quantum cascade lasers using a gas cell

We report frequency locking of two 3.5-THz third-order distributed feedback (DFB) quantum cascade lasers (QCLs) by using methanol molecular absorption lines, a proportional-integral-derivative controller, and a NbN bolometer. We show that the free-running linewidths of the QCLs are dependent on the electrical and temperature tuning coefficients....