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This paper presents an adaptive stable generalized predictive control using Takagi-Sugeno-Kang (TSK) fuzzy model for nonlinear discrete-time with time-delay systems. This controller is composed of a fuzzy second-order time-delay identifier with on-line parameter estimation, and a stable generalized predictive control with abilities of accurate tracking and disturbance rejection. Numerical simulations for controlling two highly nonlinear processes reveal excellent disturbance rejection and setpoint tracking performance of the proposed control method in comparison with other methods. The results clearly indicate effectiveness and merit of the proposed method. [ABSTRACT FROM AUTHOR]

This paper presents adaptive robust regulation methods for self-balancing and yaw motion of a two-wheeled human transportation vehicle (HTV) with varying payload and system uncertainties. The proposed regulators are aimed at providing consistent driving performance for the HTV with system uncertainties and parameter variations caused by different drivers. By decomposing the overall system into the yaw motion subsystems and the wheeled inverted pendulum, two proposed adaptive robust regulators are synthesized to achieve self-balancing and yaw motion control. Numerical simulations and experimental results on different terrains show that the proposed adaptive robust controllers are capable of achieving satisfactory control actions to steer the vehicle. [ABSTRACT FROM AUTHOR]

This paper presents a new simultaneous tracking and stabilization method by backstepping and sliding-mode control techniques for wheeled inverted pendulums. The proposed method is used to synthesize a unified controller in both kinematic and dynamic levels. In the kinematic level, virtual motion commands are designed to accomplish out simultaneous tracking and stabilization, while, in the dynamic level, two sliding-mode controllers are independently designed such that the robot can be steered to follow desired time-varying trajectories or go from one pose to another. Simulation results are conducted to show the effectiveness and performance of the proposed unified control method. [ABSTRACT FROM AUTHOR]

This paper develops an intelligent adaptive motion controller using fuzzy wavelet networks (FWN) for Mecanum wheeled omnidirectional robots (MWOR) with parameter variations. Such a controller is synthesized by backstepping and FWN which are used to on-line approximate some uncertain nonlinear term of the controller, thereby accomplishing out better motion performance. Simulation results show the effectiveness and merit of the proposed control method. [ABSTRACT FROM AUTHOR]

This paper presents an adaptive control using radial-basis-function neural networks (RBFNNs) for a two-wheeled selfbalancing scooter. A mechatronic system structure of the scooter driven by two dc motors is briefly described, and its mathematical modeling incorporating two frictions between the wheels and the motion surface is derived. By decomposing the overall system into two subsystems (yaw motion and mobile inverted pendulum), one proposes two adaptive controllers using RBFNN to achieve self-balancing and yaw control. The performance and merit of the proposed adaptive controllers are exemplified by conducting several simulations and experiments on a two-wheeled self-balancing scooter. [ABSTRACT FROM AUTHOR]

This technical note presents a behavior-based navigation method for a mobile service robot with a three-wheeled omnidirectional mobile platform. A heuristic fuzzy Kohonen clustering network (FKCN) is presented to obtain laser area weights and desired robot motion heading for all types of indoor environments. An efficient behavior-based navigation structure is then proposed to merge the heuristic FKCN with three fuzzy behaviors in order to navigate the robot without any collisions in crowded and cluttered indoor environments. Simulation and experimental results are conducted to verify the feasibility and effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

This paper presents experimental measurement techniques for the characteristics and performance of an asymmetric disk-type ultrasonic motor with single-phase current drive. A single-phase driving circuitry with a constant-current output is proposed to provide a steady driving current for the motor's stator to maintain the driving frequencies at resonant and antiresonant frequencies of the stator. Experimental results obtained from the laser vibrometer, dynamic analyzer, and photodetector are employed to investigate and discuss the characteristics and speed servoing performance of the motor with its proposed driver and a simple proportional-integral (PI) speed controller via a digital signal processor (DSP). [ABSTRACT FROM AUTHOR]

This paper presents an improved wide color-gamut technique for liquid crystal modules (LCM) with multi-phosphor white (MPW) light emitting diodes (LED) and an modified rich color image processing method. The MPW LED improves 13% of the display color gamut in comparison with standard white LED under the assumption of equal power consumption and brightness. Via many simulation results, the pixel-level rich color method is shown to obtain a superior image data by giving about 45% saturation enhancement without hue distortion. The performance and merit of the proposed technique are exemplified by conducting several experimental results on a 2.8-inch thin-film-transistor (TFT) LCM. [ABSTRACT FROM AUTHOR]

This paper presents an equivalent-circuit model of an asymmetric disc-type ultrasonic motor and discusses its applications in the evaluation of the motor's characteristics. The modeling process is based on the mechanical vibrations of the piezoelectric ceramic disk in both the radial (tangential) and coupling directions, the rigid body assumption of the rotor, and the assumption of a single contact point between the stator and the rotor with the most significant lateral elliptic motion effect. The overall model is composed of three admittance-type equivalent circuit models of the metal back plate, the stator, and the rotor. The advantages of the model are exemplified by comparing the numerical and experimental results, thereby showing that the model may be useful and pragmatic for electrical engineers in designing, simulating, and characterizing such motors. [ABSTRACT FROM AUTHOR]

This paper presents a polar-space kinematics control method to achieve simultaneous tracking and stabilization for an omnidirectional wheeled mobile robot with three independent driving omnidirectional wheels equally spaced at 120° from one another. The kinematic model of the robot in polar coordinates is presented. With the kinematic model, a kinematic control method based on feedback linearization is proposed in order to achieve simultaneous tracking and stabilization. The proposed method is easily extended to address the path following problem. Computer simulations and experimental results are presented to show the effectiveness and usefulness of the proposed control method at slow speeds. [ABSTRACT FROM AUTHOR]

This paper presents an embedded adaptive robust controller for trajectory tracking and stabilization of an omnidirectional mobile platform with parameter variations and uncertainties caused by friction and slip. Based on a dynamic model of the platform, the adaptive controller to achieve point stabilization, trajectory tracking, and path following is synthesized via the adaptive backstepping approach. This robust adaptive controller is then implemented into a high-performance field-programmable gate array chip using hardware/software codesign technique and system-on-a-programmable-chip design concept with a reusable user intellectual property core library. Furthermore, a soft-core processor and a real-time operating system are embedded into the same chip for realizing the control law to steer the mobile platform. Simulation results are conducted to show the effectiveness and merit of the proposed control method in comparison with a conventional proportional-integral feedback controller. The performance and applicability of the proposed embedded adaptive controller are exemplified by conducting several experiments on an autonomous omnidirectional mobile robot. [ABSTRACT FROM AUTHOR]

Control systems education often needs to design interesting hands-on exercises that keep students interested in the control theory presented in lectures. These exercises include system modeling, system analyses, controller syntheses, implementation, experimentation, and performance evaluation of a control system. This paper presents an interesting pedagogical tool, a self-balancing human transportation vehicle (HTV), for the teaching of feedback control concepts in undergraduate electrical, mechatronic, and mechanical engineering environments. Such a pedagogical tool can be easily and inexpensively constructed using low-tech commercial components and feedback control approaches. The effectiveness and performance of the proposed HTV system are examined by conducting several experiments on three different terrains. An education process, together with a pedagogical method, is presented to show how the developed HTV can be incorporated into the laboratory course. To increase students' hands-on experience and keep them interested in learning feedback control, this study also investigated how the enrolled students responded to this new pedagogical tool. This education method along with the HTV system is shown to be significantly effective in helping students to understand feedback control theory and practices, and also to result in more motivated and active learning. [ABSTRACT FROM AUTHOR]

Abstract  This paper presents methodologies and techniques for posture estimation and tracking of an autonomous mobile robot (AMR) using a laser scanner with at least three retro-reflectors. A three-point laser triangulation method is presented to find an initial posture of the robot and then a fuzzy extended information filtering (FEIF) method is used to improve the accuracy of the robot’s posture estimation. With the odometric information from the driving wheels, a FEIF-based posture tracking algorithm is proposed to continuously keep trace of the robot’s posture at slow speeds. Simulation and experimental results are conducted to show the efficacy and usefulness of the proposed methods. [ABSTRACT FROM AUTHOR]

This paper presents methodologies and technologies for ultrasonic localization and pose tracking of an autonomous mobile robot (AMR) by using a fuzzy adaptive extended information filtering (FAEIF) scheme. A novel ultrasonic localization system, which consists of two ultrasonic transmitters and three receivers, is proposed to estimate both the static and the dynamic position and orientation of the AMR. FAEIF is presented to improve estimation accuracy and robustness for the proposed localization system, while the system lacks sufficient information of complete models or the process and measurement noise varies with time. Static pose estimation that utilizes the averaging approach is also investigated. Six time-of-flight ultrasonic measurements, together with the vehicle's dead-reckoned localization information, are merged to update the vehicle's pose by utilizing the FAEIF sensor fusion algorithm. The proposed algorithms were implemented using an industrial personal computer with a computation speed of 800 MHz and standard C++ programming techniques. The system prototype, together with computer simulations and experimental results, was used to confirm that the system not only provides precise estimation of both the static and dynamic pose of the AMR but also provides a simple economical structure for navigational use and installation/calibration. [ABSTRACT FROM AUTHOR]

The paper presents an adaptive dimming technique to reduce backlight power consumption and enhance image contrast for global backlight applications. The proposed adaptive dimming technique consists of two new algorithms: backlight dimming algorithm and contrast enhancement algorithm. The backlight-dimming algorithm obtains appropriate 0% to 50% backlight power reduction depending on characteristics of the image data. The contrast enhancement algorithm not only reduces the adverse effect of backlight power saving, but also improves 20.75%enhancement of image contrast ratio on the average. Numerous simulation results are used for illustration of the effectiveness and merits of the proposed adaptive dimming technique. Experimental results are conducted to show the performance and usefulness of the proposed technique on a 2.2-inch mobile phone liquid crystal display (LCD) made by thin-film-transistor (TFT) technology. [ABSTRACT FROM AUTHOR]

Abstract  This paper presents an adaptive robust control method for trajectory tracking and path following of an omni-directional wheeled mobile platform with actuators’ uncertainties. The polar-space kinematic model of the platform with three independent driving omnidirectional wheels equally spaced at 120  from one another is briefly introduced, and the dynamic models of the three uncertain servomotors mounted on the driving wheels are also described. With the platform’s kinematic model and the motors’ dynamic model associated two unknown parameters, the adaptive robust controller is synthesized via the integral backstepping approach. Computer simulations and experimental results are conducted to show the effectiveness and merits of the proposed control method in comparison with a conventional PI feedback control method. [ABSTRACT FROM AUTHOR]

SUMMARYGlobal localization of mobile robots has been well studied using the extended Kalman filter (EKF) method. This paper presents a fuzzy extended information filtering (FEIF) approach to improving global localization of an indoor autonomous mobile robot with ultrasonic and laser scanning measurements. A real-time FEIF algorithm is proposed to improve accuracy of static global pose estimation via multiple ultrasonic data. By fusing odometric, ultrasonic, and laser scanning data, a real-time FEIF-based pose tracking algorithm is developed to improve accuracy of the robot's continuous poses. Several experimental results are performed to confirm the efficacy of the proposed methods. [ABSTRACT FROM AUTHOR]

An adaptive predictive control with recurrent neural network prediction for industrial processes is presented. The neural predictive control law with integral action is derived based on the minimization of a modified predictive performance criterion. The stability and steady-state performance of the closed-loop control system are well studied. Numerical simulations reveal that the proposed control gives satisfactory tracking and disturbance rejection performance for two illustrative nonlinear systems with time-delay. Experimental results for temperature control of a variable-frequency oil-cooling process show the efficacy of the proposed method for industrial processes with set-points changes and load disturbances. [ABSTRACT FROM AUTHOR]

This paper presents a Modified Stripe-RGBW (MS-RGBW) color filter structure to keep the same high resolution, and obtain a higher brightness in comparison with conventional RGB color filters. An image-processing engine is also designed to achieve sharp text image for thin-film-transistor (TFT) LCD with the MS-RGBW color filter. In MS-RGBW color filter structure, each pixel with three sub-pixels is the same area to that in the conventional RGB stripe color filter, and each row shifts two sub-pixels. The image-processing engine consists of two new.algorithms: RGB-RGBW mapping algorithm and sub-pixel rendering algorithm. The RGB-RGBW mapping algorithm obtains a new RGBW image data without distortion in hue and saturation. The sub-pixel rendering algorithm transfers RGBW data into a MS-RGBW color filter structure in order to achieve sharp text image. Numerous simulation results are provided to illustrate the merits and performance of the proposed techniques. The usefulness of the proposed techniques for mobile phone displays is exemplified by conducting several experimental results on a 2.2-inch TFT LCD. [ABSTRACT FROM AUTHOR]

In order to achieve good handling (or flying) qualities in longitudinal axis for all flight conditions, an adaptive backstepping flight control law is presented. With the backstepping technique, an adaptive controller is synthesized for the purpose of accomplishing desired responses under a wide range of flight envelope. The specification assignments for flying qualities are used for selecting essential parameters of the proposed adaptive controller for all flight conditions. In comparison with other conventional control methods, the proposed adaptive control law is much simpler and easier to construct and implement. Simulation results show that the proposed method is capable of giving desired closed-loop dynamic performance and robustness against uncertainties within the subsonic and supersonic flight conditions. [ABSTRACT FROM AUTHOR]

Abstract This paper presents methodologies and techniques for fusing inertial and ultrasonic sensors to estimate the current posture of a mobile robot navigating over indoor uneven terrain. This new type of pose tracking system is developed by means of fusing an inertial navigation subsystem (INS) and an ultrasonic localization subsystem. Extended Kalman filtering (EKF)-based algorithm for integrating both the subsystems is proposed to obtain reliable attitude and position estimates of the vehicle and to eliminate the accumulation errors caused by wheel slippage and surface roughness. Experimental results are conducted to illustrate feasibility and effectiveness of the proposed system and method. [ABSTRACT FROM AUTHOR]

A fuzzy adaptive extended information filtering (FAEIF), composed of a fuzzy tuner and the exponential weighted extended information filtering (EIF), is proposed to avoid the EIF divergence problems caused by the noise variations or occurrence of modeling errors estimates. By monitoring the innovation sequence, the fuzzy tuner adjusts on-line the performance of the EIF and thus improves the estimation accuracy and robustness of the EIF. Through simulation results, the proposed method has been shown to overcome the filter divergence problems under the noise variations and occurrence of modeling errors. [ABSTRACT FROM AUTHOR]

This paper develops methodologies and techniques for the design, analysis, and implementation of a model reference adaptive predictive temperature controller for a variable-frequency oil-cooling machine, suited for cooling high-speed machine tools. The oil-cooling process is modeled experimentally as a first-order system model with a time delay and its system parameters are identified using the recursive least-square method. Based on this model, a model reference adaptive predictive controller is proposed for achieving set-point tracking and robustness. A real-time model reference adaptive predictive control algorithm is then presented and implemented utilizing a stand-alone digital signal processor TMS320F243 from Texas Instruments Incorporated. The experimental results show that the proposed control method is proven capable of giving satisfactory performance under set-point changes, fixed loads, and load changes. [ABSTRACT FROM AUTHOR]

Examines the adaptive decoupling temperature control for an extrusion barrel in a plastic injection molding process. Establishment of a stochastic polynomial matrix model of the system; Minimization of a generalized predictive performance criterion; Comparison between the proposed control law and the other multivariable control strategies.