Digital VLSI Implementation of Piecewise-Affine Controllers Based on Lattice Approach

This paper presents a small, fast, low-power consumption solution for piecewise-affine (PWA) controllers. To achieve this goal, a digital architecture for very-large-scale integration (VLSI) circuits is proposed. The implementation is based on the simplest lattice form, which eliminates the point location problem of other PWA representations and is able to provide continuous PWA controllers defined over generic partitions of the input domain. The architecture is parameterized in terms of number of inputs, outputs, signal resolution, and features of the controller to be generated. The design flows for field-programmable gate arrays and application-specific integrated circuits are detailed. Several application examples of explicit model predictive controllers (such as an adaptive cruise control and the control of a buck-boost dc-dc converter) are included to illustrate the performance of the VLSI solution obtained with the proposed lattice-based architecture

Digital VLSI Implementation of Piecewise-Affine Controllers Based on Lattice Approach

This paper presents a small, fast, low-power consumption solution for piecewise-affine (PWA) controllers. To achieve this goal, a digital architecture for very-large-scale integration (VLSI) circuits is proposed. The implementation is based on the simplest lattice form, which eliminates the point location problem of other PWA representations and is able to provide continuous PWA controllers defined over generic partitions of the input domain. The architecture is parameterized in terms of number of inputs, outputs, signal resolution, and features of the controller to be generated. The design flows for field-programmable gate arrays and application-specific integrated circuits are detailed. Several application examples of explicit model predictive controllers (such as an adaptive cruise control and the control of a buck-boost dc-dc converter) are included to illustrate the performance of the VLSI solution obtained with the proposed lattice-based architecture.Peer reviewe

A short predictive Model Predictive Control (MPC) approach for hybrid characteristics analysis in DC-DC converter

Historically, the MPC has been successfully applied in drives system for over a decade. Furthermore, the DC-DC converter naturally deals with high switching phenomenon that contributes to the challenging in control approach. Its operation conventionally associated with PI/PID controller in order to meet the desired output. However, the PI/PID controller lacking in getting a good transient response since this controller highly depends on the controller gains. Recently, an advanced controller has been proposed in the literature for the purpose to enhance the DC-DC converter performance. Hence, in this thesis, the short prediction horizon of MPC using search tree optimization that generates low switching states phenomenon is proposed. The MPC algorithm is developed based on the hybrid characteristic signals from the DC-DC converter. The load changes due to the increasing or decreasing the loads (could be happened of heating effect) will affect the tracking of the output voltage. The Kalman Filter (KF) is used for load estimation for smoothing and tracking the output voltage. The performance of short prediction horizons is being compared to PI controller in terms of transient response during the start-up scenario. The results show that the proposed controller has a better response than PI controller, which is the overshoot has been reduced to more than 50% and the settling time more faster about 25% than PI controller during start-up scenario. Therefore, this control approach for DC-DC buck converter has produced the promising output transient performance when compared with the conventional PI controller while also minimizing the switching sequence phenomenon

Approximately bisimilar symbolic models for incrementally stable switched systems

Switched systems constitute an important modeling paradigm faithfully describing many engineering systems in which software interacts with the physical world. Despite considerable progress on stability and stabilization of switched systems, the constant evolution of technology demands that we make similar progress with respect to different, and perhaps more complex, objectives. This paper describes one particular approach to address these different objectives based on the construction of approximately equivalent (bisimilar) symbolic models for switched systems. The main contribution of this paper consists in showing that under standard assumptions ensuring incremental stability of a switched system (i.e. existence of a common Lyapunov function, or multiple Lyapunov functions with dwell time), it is possible to construct a finite symbolic model that is approximately bisimilar to the original switched system with a precision that can be chosen a priori. To support the computational merits of the proposed approach, we use symbolic models to synthesize controllers for two examples of switched systems, including the boost DC-DC converter.Comment: 17 page

A novel sliding mode controller for DC-DC boost converters under input/load variations

© 2015 IEEE. In this paper a simple sliding mode controller based on the averaging state space model is proposed for a DC-DC boost converter. It is demonstrated to be easily implemented and has time-variant sliding coefficients. The proposed controller can effectively regulate the output voltage by controlling the switch states (through the dynamic duty cycles) even when the input voltage, load or output command varies. Furthermore the controller is independent of the inductor current and the load, although the load value is needed when designing the sliding coefficients. The constant switching frequency is maintained thus simplifying the design procedure, enhancing the regulation properties and benefiting the filter design. The controller has good dynamic response, overshoot damping and robustness. Comparative simulations are carried in MATLAB/Simulink between the proposed approach and a widely used PID controller to verify the effectiveness and feasibility of the proposed method

A Unity Power Factor Boost Rectifier with a Predictive Capacitor Model for High Bandwidth DC Bus Voltage Control

Single phase rectifiers with power factor correction circuits based on the boost converter find broad application in consumer equipment. A fundamental design difficultly is caused by the need to trade off the input line current wave shape and the dynamic response of the output energy storage capacitor voltage regulation loop. The energy balance requirement inherent in single phase systems forces a significant 100Hz voltage ripple on the output capacitor. A high bandwidth voltage regulation loop will feed back enough of the 100Hz component to distort the current reference signals for the inner current control loop distorting the line wave shape. A reference model can be used to construct a ripple free estimate of the capacitor voltage. This paper shows that improved output capacitor voltage regulation can be achieve simultaneously with a high quality input current spectrum

An Iterative Learning Based Compensation in Model Predictive Control for DC/DC Boost Converter

Attributed to the increased processing power of modern microprocessors, model predictive control (MPC) for power converters is gaining more attention. However, the non-minimum phase behavior in DC/DC boost converters complicates the design of model predictive control. When controlling the output voltage directly, it fails to track the reference with short prediction horizons, nevertheless, long prediction horizons cause a heavy computational burden. Although controlling the inductor current is a feasible option with a short prediction horizon, the control accuracy of the output voltage cannot be guaranteed. To address this issue, this work introduces a compensation term into the difference equation of the inductor current. Then the proportion of the compensation term is designed with an iterative learning method to improve the control accuracy. Finally, the results indicate the proposed method can ensure a good control performance with different load occasions