Reset Action Research Articles

New Tuning Rules of PI+CI Controllers for First-Order Systems

The reset control is a simple nonlinear control approach where the states of the controller are conducted to zero when a particular condition is satisfied. The PI+CI is a controller that mixes the simplicity of PI controllers with the benefits of a reset action to mitigate the fundamental limitations of linear control. However, the tuning of this kind of controller, with three parameters, two for the linear part and one for the nonlinear one, is not trivial. In this paper, simple tuning rules for PI+CI are proposed for both tracking and regulation problems, assuming first-order dynamics for the plant. The resulting control scheme, for which the reset coefficient is computed from exponential functions, is simulated and compared with an ideal PI+CI where the reset coefficient is obtained using rules available in the literature. Similar results are obtained for the tracking problem, and optimal performance based on the Integral Absolute Error (IAE) is also obtained for the regulation problem. These new rules, in contrast to those already existing in the literature, depend only on closed-loop specifications. Furthermore, the framework based on the minimization of IAE, used to obtain the proposed rules, makes it possible to consider for the first time the tracking and regulation problems simultaneously, i.e., cases where setpoint changes and disturbance arrivals can occur at the same time before reaching a new steady state. The results are validated using a set of study cases.

Leader-following consensus of linear multi-agent systems via reset control: A time-varying systems approach

In this work, we address the leader-following consensus problem of multi-agent systems by developing a novel reset consensus protocol with a time-varying gain matrix. The reset consensus protocol is distinct from existing results in the sense that it integrates a high-dimensional element with the reset actions triggered by a prescribed reset band. After converting the original closed-loop system to an equivalent linear time-varying system, we develop the time-varying system approach for linear multi-agent system over fixed/switching networks. It further shows that the proposed reset consensus protocol helps to improve the transient performance. Finally, two numerical examples are presented to illustrate the theoretical results and effectiveness.

Designing an Optimal Reset Controller for TS Fuzzy Systems

This study considers the problem of designing a reset dynamic output feedback controller (R-DOFC) for continuous-time nonlinear dynamics modeled by a Takagi-Sugeno (TS) fuzzy form. The exponential convergence of the closed-loop system state trajectories to the equilibrium point is satisfied by designing the fuzzy dynamic output feedback controller (DOFC) without reset action via the linear matrix inequality (LMI) technique. After that, by developing an optimization problem, the after-reset value is designed by using system output measurements at each reset time. In this approach, a genetic algorithm is adopted to minimize the proposed cost function of certain transient performances to achieve the best reset time instants. Moreover, sufficient conditions for choosing the DOFC after-reset value are formulated in the form of LMIs. The proposed reset fuzzy DOFC is applied to two nonlinear systems. The merits of the proposed reset DOFC are demonstrated by comparing the obtained results with those of other approaches.

Lamb wave-based real-time damage location system with integrated internet of things

In this paper, an automated Structural Health Monitoring (SHM) system that uses Lamb waves is presented. A miniaturized prototype named ‘Real-Time Damage Location System’ (RTDLS) is designed and fabricated for thin plate structure, which can automatically locate single damage in an area of 100 mm × 100 mm by manually pressing a tactile button or by using an Internet of Things (IoT) platform. RTDLS is a lightweight, mobile, and plug-and-play device that uses 3 piezoelectric wafer transducers. It uses the pitch-catch technique with a novel damage location algorithm to locate damage in a plate. It displays the location of the identified damage on an LCD screen and on the webpage through live broadcasts using an IoT platform. RTDLS can store Lamb wave data corresponding to the pristine and damaged states of the structure in a FLASH memory so that no data is erased until reset action is performed.

Optimizing DODAG Build with RPL Protocol

In the lossy wireless network routing system based on RPL technology, an improved DODAG construction optimization scheme is proposed for sensor nodes with low-power dissipation in the interference environment. If a node discovers that all paths between it and its neighbors have failed, the node reset action begins. Once the node reset is complete, the DODAG system build process is resumed. This prevents the DODAG root from initiating a global fix by incrementing the DODAG VersionNumer to produce a new version of the DODAG in a disruptive environment. The power loss caused by this global repair operation is avoided. The performance of DODAG in interference environment is enhanced, and the data retransmission rate is reduced.

Investigation of capacitor-less integrate and fire neuron by using dual-gate a PN-body tied silicon on insulator field-effect transistor

In this study, integrate and fire neuron by using a dual-gate (DG) PN-body tied (PNBT) silicon on insulator field-effect transistor (SOI-FET) was investigated. We found out that the DG PNBT SOI-FET has the integrate and fire function in a single device. The floating body and the positive feedback effect can perform the functions of the capacitor and comparator, respectively. The device can generate a continuous spike and also a single spike signal with the additional reset scheme. The reset action requires a recovery time, which can be controlled by voltage conditions. It has a chance of making a refractory period function. These characteristics mean that it is possible to realize the capacitor-less small footprint neuron circuit with the DG PNBT SOI-FET.

Innovative design of side mould structure based on TRIZ theory

In order to meet the requirements of domestic prefabricated buildings and PC production lines, taking the side mould structure as the research object, an innovative design of the side mould structure based on TRIZ theory is proposed. The tools of TRIZ’s nine-screen method and conflict matrix are used to complete the innovation of the plugging device for the side mould reinforcement hole,and by using steel wire connection, the aluminum alloy sealing device can complete synchronous action and solve the problem of reinforcement hole leakage. Through the object field analysis tool in the TRIZ theory, to establish the function related to the existing system or new technology system problems, the double rocker mechanism is used to make the reset action and the demolding action of the side mould sealing device complete in a linked manner, to realize the design of the demoulding device and the side mould fixing device. The calculation and verification of the side mould structure verify that the side mould stiffness meets the production requirements, and improves the accuracy and placement accuracy of the side mould.

Optimal robust model predictive reset control design for performance improvement of uncertain linear system

This study aims to design a robust reset dynamic output feedback control (DOFC) for a class of uncertain linear systems. This procedure is performed as following. First, the elements of the robust DOFC are designed via the linear matrix inequality (LMI) technique such that closed-loop exponential stability is achieved. Second, reset law which contains value of after reset and a constraint for the reset action is determined. Genetic algorithm (GA) is applied to minimize the proposed objective function to find the reset times by using the specified after reset value for individual reset instances. To do this, a model-predictive-based optimization is adopted by using output information. The proposed robust controller is applied to two uncertain systems; distillation column, and B747-100/200 aircraft model. The merits of the proposed robust reset controller in improving transient performance are demonstrated by comparing its results with state-of-the-art methods.

Sliding Mode Controller Based on a Hybrid Surface for Tracking Improvement of Non-Linear Processes

This paper presents the synthesis of a sliding mode controller based on a hybrid surface (SMC-HS) as an alternative to improve the performance of the traditional SMC in its transient response. The combination of two sliding surfaces is carried out in order to obtain the advantages of both. Through reset actions, the use of one or other surface is prioritized. The improvement offered by the proposal is quantified by performance indexes when the new controller is tested in a non-linear, self-regulating model.

Reset Control for Vibration Disturbance Rejection

The high tech industry which requires fast stable motion with nanometer precision continues to mainly use PID which is limited by fundamental linear control limitations. Floor vibrations as disturbance significantly affect performance and their rejection is particularly affected by these limitations. Reset control has provided a promising alternative to surpass these, while simultaneously allowing the use of industry standard loop-shaping during design. However, the reset action introduced higher order harmonics can induce unwanted dynamics and negatively influence performance. This paper investigates two reset control strategies namely (1) band-pass phase lag reduction and (2) phase compensation to reduce the negative effects of higher order harmonics. The strategies are tested on a precision positioning stage for vibration rejection and the results show that phase compensation provides better performance compared to other tested strategies.

Stability analysis and design of model predictive reset control for nonlinear time-delay systems with application to a two-stage chemical reactor system

This paper presents a systematic Lyapunov-based approach for reset control of nonlinear time-delay system. The reset controller consists of a base controller and a reset law that enforces resets to the controller states. The reset actions are triggered if predefined reset conditions are satisfied and reset law is used to determine reset values of the controller states. A model predictive strategy is proposed to design the reset law by solving a linear matrix inequality optimization problem. Based on Lyapunov–Krasovskii approach, the reset controller with guaranteed asymptotical stability is synthesized. Finally, we apply the developed method to the control design of a two-stage chemical reactor with delayed recycle streams, and the simulation results verify the effectiveness of the main results.

Surge protection design with surge-to-digital converter for microelectronic circuits and systems

A surge protection design with surge-to-digital converter is proposed to provide the surge protection for microelectronic products with more flexible applications. The proposed surge-to-digital converter can transfer the occurrences of the surge events into digital output codes by classifying the voltage levels of surge events. It can be used to avoid unwanted power-on reset action, redundant power consumption, or unexpected soft errors, achieving the stability improvement of microelectronic systems. With this surge-to-digital converter, a surge protection design against a surge test of 25 V can clamp the peak voltage of VDD from 22.2 V to 5.6 V. The proposed converter has been verified in a 0.18-μm CMOS process.

Reset Controller Design Based on Error Minimization for a Lane Change Maneuver.

An intelligent vehicle must face a wide variety of situations ranging from safe and comfortable to more aggressive ones. Smooth maneuvers are adequately addressed by means of linear control, whereas more aggressive maneuvers are tackled by nonlinear techniques. Likewise, there exist intermediate scenarios where the required responses are smooth but constrained in some way (rise time, settling time, overshoot). Due to the existence of the fundamental linear limitations, which impose restrictions on the attainable time-domain and frequency-domain performance, linear systems cannot provide smoothness while operating in compliance with the previous restrictions. For this reason, this article aims to explore the effects of reset control on the alleviation of these limitations for a lane change maneuver under a set of demanding design conditions to guarantee a suitable ride quality and a swift response. To this end, several reset strategies are considered, determining the best reset condition to apply as well as the magnitude thereto. Concerning the reset condition that triggers the reset action, three strategies are considered: zero crossing of the controller input, fixed reset band and variable reset band. As far as the magnitude of the reset action is concerned, a full-reset technique is compared to a Lyapunov-based error minimization method to calculate the optimal reset percentage. The base linear controller subject to the reset action is searched via genetic algorithms. The proposed controllers are validated by means of CarSim.

Optimal controller synthesis for second order time delay systems with at least one RHP pole

An optimal H2 minimization framework is proposed in this paper for devising a controller of PID in nature, based on a refined IMC filter configuration. The tuning strategy is for controlling time delay system with at least one pole which falls on the right half of the s-plane. An underdamped model based filter is used in place of the unity damping ratio (critically damped) filter available in the literature to improve the reset action. The method has a single adjustable closed loop tuning parameter. Guidelines have been provided for choosing the pertinent tuning parameter based on the sensitivity function. Simulation work has been executed on diverse unstable models to support the advantages of the proposed scheme. The proposed controller yields improved performances over other recently reported tuning techniques in the literature. Experimental implementation is carried out on an inverted pendulum for demonstrating the practical applicability of the present method. The efficacy of the intended controller design is quantitatively analyzed using the time integral performance index.

Compensated hybrid PI controllers for sampled-data controlled systems

Abstract In this paper we consider sampled-data systems controlled by hybrid PI controllers. In these systems, the sample time may induce some undesirable overshoot due to the postponed reset action on the control integral state, which deteriorates the performance of the closed loop by leading to output overshoot as well as to larger settling time values. We propose a methodology to compute a bounded compensating signal to be added to the control input that minimizes the overshoot and the settling time. The action of the compensating signal synchronizes the reset instants of the hybrid PI controller with the sample-time for a class of systems. The proposed methodology is tested in a laboratory setup system composed of two connected water reservoirs with capacity of 200 liters each, actioned by a variable velocity pump. The control objective is to regulate the level of the first tank and to reject disturbances. We compare the performances achieved by two different hybrid PI schemes with and without the proposed additive compensating signal. The experimental tests illustrate the performance, robustness and disturbance rejection achieved by our approach when applied to uncertain systems.

Discrete‐time triggered reset law design based on model predictive strategy for linear systems

This study investigates discrete-time triggered reset law design for linear systems in order to adapt reset control to computer-based implementation. The reset actions are triggered at discrete sampling times if predefined reset conditions are satisfied, and reset law is used to determine reset values of the controller states. A discrete-time switched system model of the reset control systems is established, then, a model predictive strategy is proposed to design the reset law by solving a linear matrix inequality optimisation problem. Moreover, the proposed method is extended to observer-based reset law design. The obtained results are applied to numerical example and typical continuous stirred tank reactor system, simulations show that the proposed design is effective.

Stability analysis of periodic triggering reset control systems

In most literature related to reset control, the reset actions are triggered by continuous monitoring triggering reset conditions, which is not suitable for computer-based implementation. This paper considers periodic triggering reset control, where the reset actions are only triggered at periodically sampling instants. Hybrid system approach is given to analyze the asymptotic stability and L2 gain property, and less conservative switched system approach is presented for asymptotic stability analysis. The comparison of the two approaches is discussed. Moreover, novel reset conditions are given to improve the overshoot performance. Simulations are presented to support our results.

Stability analysis of reset positive systems with discrete-time triggering conditions

This paper discusses the problem of stability analysis of reset positive systems based on discrete-time triggering conditions. A reset control system is positive, if for any nonnegative initial condition and input, its states and outputs are nonnegative whenever the reset actions occur. First, the relationship between reset positive systems (RPSs) with discrete-time triggering conditions and discrete-time switched positive systems (SPSs) is established, by which the stability problem of RPSs is transformed to that of SPSs. Then, some sufficient and necessary conditions of stability and tracking problem for RPSs are given.

Towards [formula omitted]-stability of discrete-time reset control systems via dissipativity theory

This paper proposes conditions on input–output stability of discrete-time reset systems by using some key dissipativity properties. In the continuous-time setting, dissipativity of the base linear system is preserved under reset actions if the storage function is decreasing at reset times. Indeed, when the reset system is a full reset system, the dissipativity of the base linear system ensures the dissipativity of the reset system. However, in the discrete-time setting, this condition on the storage function is not enough to ensure the dissipativity of the base linear system. We define some dissipativity properties of discrete-time reset systems and give an appropriate definition of the reset system in order to preserve the (Q,S,R)−dissipativity of the base linear system under reset actions. As a result, ℓ2-stability of feedback interconnected dissipative control reset systems is obtained.

Frequency domain properties of reset systems with multiple reset anticipations

A reset controller is a controller that operates most of the time as a linear system, except when some condition holds. The typical reset condition is the zero crossing of the tracking error signal, e ( t ) = 0. At this moment, the controller performs a zero resetting action on its state. It has been shown that reset control is able to overcome fundamental linear limitations. This article studies, within a frequency-domain framework, the generalisation of reset control systems based on including some anticipation on the reset condition.This has a favourable phase lead effect. The paper discusses different reset anticipations schemes, including multiple reset actions in the same period, computes Fourier harmonics and describing function of general reset controllers and shows explicitly the overcoming of frequency-domain limitations (Bode's gain-phase relation).