MIQPSO-backstepping tracking controller design and experimental validation for multi-rope quay cranes

This article studies the problems of H ∞ output tracking performance analysis and controller design for networked control systems (NCSs) with time delay and packet dropout. By using linear matrix inequality (LMI)-based method, H ∞ output tracking performance analysis and controller design are presented for NCSs with constant sampling period. For NCSs with time-varying sampling period, a multi-objective optimisation methodology in terms of LMIs is used to deal with H ∞ output tracking performance analysis and controller design. The designed controllers can guarantee asymptotic tracking of prescribed reference outputs while rejecting disturbances. The simulation results illustrate the effectiveness of the proposed H ∞ output tracking controller design.

A fuzzy logic based approach to a camera tracking system has been developed to support proximity operations and traffic management around the Space Station Freedom. Fuzzy sets and fuzzy logic based reasoning, were used in a control system which utilized images from a camera and generated the required pan and tilt commands to track and maintain a moving object in the cameras field of view. The design of the tracking controller is described with the details of the membership functions and the rulebase. The software simulation setup including implementation of the fuzzy controller, and the development of the software algorithm for the camera model and gimble drives, is discussed in a description of test cases, and an analysis of the results is given. The performance of the controller and future work in the camera tracking project are outlined. >

Dynamic modeling, controller design and experimental validation of a planar motion stage for precision positioning

This paper studies the problems of H <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</inf> output tracking performance analysis and controller design for networked control systems (NCSs) with time delay and packet dropout. By defining new Lyapunov function and using the discrete Jensen inequality, linear matrix inequality (LMI)-based H <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</inf> output tracking performance analysis and controller design are presented. The adoption of the discrete Jensen inequality may reduce the computational complexity of the obtained results. The designed controllers can guarantee asymptotic tracking of prescribed reference outputs while rejecting disturbances. The simulation results illustrate the effectiveness of the proposed H <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</inf> output tracking controller design.

Global Practical Tracking for a Hovercraft with Unmeasured Linear Velocity and Disturbances

For scanning applications, damping and tracking controllers are employed in a dual‐loop fashion. Whilst these damping and tracking controllers are designed sequentially in literature (damping first, tracking later), it has been found that the tracking controller (typically integral or proportional–integral) influences the ‘desired’ pole locations (and thereby its damping performance) achieved by the positive acceleration, velocity and position feedback (PAVPF) damping controller. This work starts by first highlighting this unwanted effect that results in low positioning bandwidth. To address this drawback, this work presents the design, analysis and experimental validation of the simultaneous design method for the PAVPF control‐based combined damping and tracking scheme, aimed at achieving accurate, high‐bandwidth nanopositioning. It also details a recursive analytical method to simultaneously optimise the damping and tracking controller parameters resulting in almost a three‐fold increase in closed‐loop bandwidth when compared with the traditional sequential method. To further confirm the advantages of the proposed simultaneous design method, comparative experimental results conducted on one axis of a piezo‐actuated nanopositioner are presented. Significant improvements in the steady‐state positioning as well as transient response are noted. These improvements combined, result in significant gains in the raster scanning performance of nanopositioning stages.

Considering input constraints and parameter uncertainty of the nonholonomic wheeled mobile robots, a new control law has been designed in this paper to solve the tracking and stabilization control problems simultaneously. The asymptotic convergence of the stabilization or tracking errors is achieved by a smooth controller with time-varying feedback parameters subject to set conditions. A geometric-based parameter design strategy is employed to overcome the difficulties resulting from input constraints. With the parameter design strategy, the designed parameters satisfy the set conditions and the control inputs stay in the constrained domain. Experimental studies have been conducted to verify the effectiveness of the proposed control law.

In this paper, we present the functional design and experimental validation of network coding technology over hybrid networks including satellite links. We first describe our design framework based on a holistic modelling of (overlay) heterogeneous networking satellite scenarios. We then define different types of logical nodes depending on their encoding, re-encoding and decoding functionalities and whether or not the satellite (overlay) application designer has control over them. Nodes are assumed strategically chosen to recode, which may result in a small number of re-encoding nodes that suffice to optimize selected performance metrics. Our main contribution is a system-oriented functional design of network coding that enables flexible instantiation of different types of network codes via configurable network coding (C-NC) functions. Random or structured NC coefficients can be remotely or locally generated and a packet scheduler can forward packets according to different policies. The choice of coefficients and overall NC scheme depend on the SATCOM-specific performance target, namely delay or bandwidth constraints. Here, we present a preliminary design and experimental testebed validation for the case of delay constrained transmission. Our results show the practical benefits of re-encoding and performance tradeoffs of different network coding schemes. In particular, our results show the good structural properties and delay-reliability tradeoffs of our novel proposal of structured network codes using Pascal matrices due to the regenerative properties of the coding coefficients.

System identification and model based controller design is an increasingly important area for UAS research. As UASs are used in more challenging conditions, it is critical to have accurate system identification, controller design, and controller validation for improved aircraft safety. The roll controller of a flying-wing UAS is examined in this paper including aircraft system identification, controller design, and controller validation. This paper also introduces a new procedure for utilizing frequency domain analysis to identify and validate the lateral directional models and roll controller design of a UAS. Good agreement is observed between simulated roll controller performance and UAS flight test results, which showed the effectiveness of the overall system identification and control design practice.

This paper presents a route-optimized drive mode switching control method for plug-in hybrid vehicles (PHVs) and its experimental validation. The research objective is to reduce fuel usage in situations where energy consumption along a route is probabilistically estimated from historical driving data. To address this, this study develops a driving-route model based on road grades and vehicle speed distributions with terrain maps and driving profiles. The driving-route model allows us to predict fuel and electricity demands on the planned route by applying energy consumption maps relating to drive modes of a PHV on the market. Moreover, the driving-route model can be shared among any PHVs, even if the powertrain properties differ. These models are leading to formulate an integer linear programming problem deciding the drive modes for reducing fuel consumption. In addition, this paper introduces an experimental system to show the proposed approach is applicable to the actual PHV. The experimental validation on the PHV indicates that this method can improve fuel efficiency compared with that of a conventional method.

This paper presents a cascaded trajectory tracking controller and a control gains selection procedure for nonholonomic car-like wheeled mobile robots with steering and velocities controllers in the tracking control loops. The trajectory tracking controller enables stable tracking control of trajectories for the car-like mobile robots in the presence of the robot's velocity and steering control latencies. Also, the proposed tracking control solution provides a systematic approach to implementing the tracking controller onto the real car-like mobile robots without requiring any dynamical model of the robot's steering and velocities control systems. This feature avoids the need for ad-hoc control parameters tuning when implementing the tracking controller. The trajectory tracking controller was validated in both simulations and experimentations. The tracking controller has been applied on a car-like pickup truck for experimentations in both on-road and off-road environments. The controller was tested up to the speed of 5.4m/sec in off-road environments. The obtained results confirm the effectiveness of the proposed tracking controller.

This paper studies the model reference H ∞ tracking control problem of networked control systems (NCSs) with random packet dropout in controller-to-actuator channels. A general packet dropout model in multiple channels case is adopted to formulate the information missing in the communication networks. The multiple channel packet dropout model results in complexities and difficulties in the tracking controller design. A latest received data dependent Lyapunov function is proposed and exploited to develop a sufficient condition for the H ∞ tracking controller design in terms of a linear matrix inequality (LMI). The proposed controller design method can guarantee asymptotic tracking of prescribed reference outputs while rejecting disturbances in mean square sense. A numerical example is given to illustrate the effectiveness of the proposed tracking controller design method.

This paper studies the model reference H ∞ tracking control problem of networked control systems (NCSs) with random packet dropout in controller-to-actuator channels. A general packet dropout model in multiple channels case is adopted to formulate the information missing in the communication networks. The multiple channel packet dropout model results in complexities and difficulties in the tracking controller design. A latest received data dependent Lyapunov function is proposed and exploited to develop a sufficient condition for the H ∞ tracking controller design in terms of a linear matrix inequality (LMI). The proposed controller design method can guarantee asymptotic tracking of prescribed reference outputs while rejecting disturbances in mean square sense. A numerical example is given to illustrate the effectiveness of the proposed tracking controller design method.

We present experimental realization and validation of the six-port design of integrating sphere photometers for total luminous flux measurement, which significantly improves the uniformity of spatial response compared to the conventional single-port design. Construction, measurement procedure, and data acquisition of the realized instrument with a radius of 1m are described. Measurement of the spatial response distribution function confirms the expected effect of improving the uniformity by averaging the signals from the six detection ports. The related spatial mismatch error is determined to be less than 1.4% for all the realistic cases of beam angles and directions of a test lamp mounted in the vicinity of the sphere center. As a result, we confirm that the realized six-port instrument allows us to eliminate the complicated spatial mismatch correction procedure by adding a relative standard uncertainty of only 1.4/3%≈0.81%, which offers a great practical benefit for testing solid-state lighting products of various beam characteristics.

This paper addresses the design and experimental validation of a linear robust static output feedback controller for a 150 mm span fixed wing micro air vehicle (MAV). Severe coupling between longitudinal and lateral dynamics of the MAV lead to the design of a multivariable controller for the combined dynamics. The control design problem is posed in the framework of static output feedback (SOF) due to the inexpensive computational requirements for implementation. The multiobjective control design problem including stability requirements, closed loop damping ratio requirements and H∞ norm minimization is solved using the hybrid technique of linear matrix inequalities (LMI) and genetic algorithm (GA). The design is carried out in the discrete time domain, facilitating in direct implementation of the multivariable controller in the onboard autopilot hardware. The robustness of the resulting closed loop system under parametric uncertainties is evaluated using structured singular value analysis. The effectiveness of the proposed controller is demonstrated through outdoor flight trial of the micro air vehicle with a customized lightweight autopilot hardware.