In recent years, many successful robotic manipulator designs have been introduced. However, there remains the challenge of designing a manipulator that possesses the inherent safety characteristics...

/pdf/a-new-actuation-approach-for-human-friendly-robot-design-2ve2okyyoq.pdf

A New Actuation Approach for Human Friendly Robot Design

This paper proposes a wind speed estimation based sensorless maximum wind power tracking control for variable-speed wind turbine generators (WTGs). A specific design of the proposed control algorithm for a wind turbine equipped with a doubly fed induction generator (DFIG) is presented. The aerodynamic characteristics of the wind turbine are approximated by a Gaussian radial basis function network based nonlinear input-output mapping. Based on this nonlinear mapping, the wind speed is estimated from the measured generator electrical output power while taking into account the power losses in the WTG and the dynamics of the WTG shaft system. The estimated wind speed is then used to determine the optimal DFIG rotor speed command for maximum wind power extraction. The DFIG speed controller is suitably designed to effectively damp the low-frequency torsional oscillations. The resulting WTG system delivers maximum electrical power to the grid with high efficiency and high reliability without mechanical anemometers. The validity of the proposed control algorithm is verified by simulation studies on a 3.6MW WTG system. In addition, the effectiveness of the proposed wind speed estimation algorithm is demonstrated by experimental studies on a small emulational WTG system.

Wind Speed Estimation Based Sensorless Output Maximization Control for a Wind Turbine Driving a DFIG

This paper gives a unified and historical review of observer design for the benefit of practitioners. It is unified in the sense that all observers are examined in terms of: 1) the assumed dynamic structure of the plant; 2) the required information, including the input signals and modeling information of the plant; and 3) the implementation equation of the observer. This allows a practitioner, with a particular observer design problem in mind, to quickly find a suitable solution. The review is historical in the sense that it follows the evolution of ideas in observer design in the last half century. From the distinction in problem formulation, required modeling information and the observer design goal, we can see two schools of thought: one is developed in the framework of modern control theory; the other is based on disturbance estimation, which has been, to some extent, overlooked.

/pdf/a-survey-of-state-and-disturbance-observers-for-b5mvoxe6ux.pdf

A survey of state and disturbance observers for practitioners

The modular multilevel converter (MMC) is distinguished by its modularity that is the use of standardized submodules (SMs). To enhance reliability and avoid unscheduled maintenance, it is desired that an MMC can remain operational without having to shut down despite some of its SMs are failed. Particularly, in this paper, complete fault diagnosis and tolerant control solution, including the fault detection, fault tolerance, fault localization, and fault reconfiguration, have been proposed to ride through the insulated gate bipolar transistor open-circuit failures. The fault detection method detects the fault by means of state observers and the knowledge of fault behaviors of MMC, without using any additional sensors. Then, the MMC is controlled in a newly proposed tolerant mode until the specific faulty SM is located by the fault localization method; thus, no overcurrent problems will happen during this time interval. After that, the located faulty SM will be bypassed while the remaining SMs are reconfigured to provide continuous operation. Throughout the fault periods, it allows the MMC to operate smoothly without obvious waveform distortion and power interruption. Finally, experimental results using a single-phase scaled-down MMC prototype with six SMs per arm show the validity and feasibility of the proposed methods.

Fault Diagnosis and Tolerant Control of Single IGBT Open-Circuit Failure in Modular Multilevel Converters

Recent research has proposed mainstream traffic flow control (MTFC), enabled via variable speed limits (VSLs), as a novel motorway traffic management tool and has demonstrated its efficiency based on sophisticated optimal control methods that may face difficulties in practical field implementations. A simple local MTFC feedback controller is designed in this paper, taking into account a number of practical requirements and restrictions. The MTFC controller relies only on readily available real-time measurements (no online model usage and no demand predictions are needed) and is therefore robust and suitable for field implementations. The controller is evaluated in simulation and compared with optimal control results. Despite its simplicity, the new controller's performance is shown to approach the optimal control results while considering several practical and safety restrictions for a number of investigated scenarios.

Local Feedback-Based Mainstream Traffic Flow Control on Motorways Using Variable Speed Limits

High-performance servo drives are often limited by mechanical load resonance. In this paper, seven methods of resonant-load control are compared for their ability to improve performance in the presence of a low-frequency (100 Hz) lightly damped resonance. The seven methods are: notch filter, bi-quad filter, rigid body observers, low-pass filter, observer filtering, active resonance damping and center-of-mass control. Several of the methods are based on filtering the command signal; the remaining methods are based on signals acquired from an observer. Development of these methods is presented; each method is applied to a physical system and evaluated for effects on command response and dynamic stiffness.

Resonant load control methods for industrial servo drives

Acknowledgements Safety Chapter 1 Control Systems and the Role of Observers Chapter 2 Control-System Background Chapter 3 Review of the Frequency Domain Chapter 4 The Luenberger Observer: Correcting Sensor Problems Chapter 5 The Luenberger Observer and Model Inaccuracy Chapter 6 The Luenberger Observer and Disturbances 1 Chapter 7 Noise in the Luenberger Observer Chapter 8 Using the Luenberger Observer in Motion Control References Appendix A Observer-Based Resolver Conversion in Industrial Servo Systems Appendix B Cures for Mechanical Resonance in Industrial Servo Systems Appendix C European Symbols for Block Diagrams Appendix D Development of the Bilinear Transformation Appendix E Solutions of Exercises Index

/pdf/observers-in-control-systems-a-practical-guide-3lgqnb24ur.pdf

Observers in Control Systems: A Practical Guide

From the Publisher:
Learn to apply control theory to practical systems with a personalcomputer! Control System Design Guide offers more than thirty computer programs that circuit designers can use to design control systems. Electrical and mechanical engineers who integrate controllers in systems design will find practical and convenientapproaches to analog controllers, digital controllers, filters, and modeling and loop analysis in this application-oriented guide.

/pdf/control-system-design-guide-using-your-computer-to-3plb30i63l.pdf

Control System Design Guide: Using Your Computer to Understand and Diagnose Feedback Controllers

Introduction to Controls The Frequency Domain Tuning a Control System Delay in Digital Controllers The z-Domain Six Types of Controllers Disturbance Response Feed-Forward Filters in Control Systems Introduction to Observers in Control Systems Introduction to Modeling Nonlinear Behavior and Time Variation Seven Steps to Developing a Model Encoders and Resolvers Basics of the Electric Servomotor and Drive Compliance and Resonance Position-Control Loops Using the Luenberger Observer in Motion Control. Appendices: Active Analog Implementation of Controller Elements European Symbols for Block Diagrams The Runge-Kutta Method Development of the Bilinear Transformation The Parallel Form of Digital Algorithms Basic Matrix Math.

Control system design guide : a practical guide

A seven-step procedure for developing a model is presented: determining the purpose of the model, selecting units, identifying the system, building the block diagram, selecting the frequency or time domain, writing the model equations, and verifying the model. Next, the process of migrating the system from simulation to deployment is discussed including using two advanced migration techniques: Rapid Control Prototype (RCP) and Hardware In the Loop (HIL). A simple model is converted from simulation to RCP using National Instruments LabVIEW.

George Ellis

Papers

Resonant load control methods for industrial servo drives

Observers in Control Systems: A Practical Guide

Control System Design Guide: Using Your Computer to Understand and Diagnose Feedback Controllers

Control system design guide : a practical guide

Model Development and Verification