Fractional Order PID Controller Tuning by Frequency Loop-Shaping: Analysis and Applications

abstract: The purpose of this dissertation is to develop a design technique for fractional PID controllers to achieve a closed loop sensitivity bandwidth approximately equal to a desired bandwidth using frequency loop shaping techniques. This dissertation analyzes the effect of the order of a fractional integrator which is used as a target on loop shaping, on stability and performance robustness. A comparison between classical PID controllers and fractional PID controllers is presented. Case studies where fractional PID controllers have an advantage over classical PID controllers are discussed. A frequency-domain loop shaping algorithm is developed, extending past results from classical PID’s that have been successful in tuning controllers for a variety of practical systems.Dissertation/ThesisDoctoral Dissertation Electrical Engineering 201

Modeling and supervisory control design for a combined cycle power plant

The traditional control strategy based on PID controllers may be unsatisfactory when dealing with processes with large time delay and constraints. This paper presents a supervisory model based constrained predictive controller (MPC) for a combined cycle power plant (CCPP). First, a non-linear dynamic model of CCPP using the laws of physics was proposed. Then, the supervisory control using the linear constrained MPC method was designed to tune the performance of the PID controllers by including output constraints and manipulating the set points. This scheme showed excellent tracking and disturbance rejection results and improved performance compared with a stand-alone PID controller’s scheme

Genetic design of unconstrained digital PID controllers

In previous genetic design procedures, the equations for the digital PID controllers were incorporated into the genetic algorithm in order to obtain optimally tuned values of various controller parameters for finite sampling frequencies. The performance of PID controllers constrained by such design equations may be sub-optimal and so this paper illustrates the use of genetic algorithms in selecting controller matrices for PID controllers without using controller design equations. This unconstrained genetic design methodology is illustrated in this paper by the design of model-following flight-control systems for the F-16 aircraft.published_or_final_versio

A new methodology for designing PID controllers

It is known that it is impossible to select fixed gains for a PD controller that will critically damp the response to disturbances for all configurations of a given robot system. Because of this the potential for overshoot is always present and cannot be avoided unless the system is severely overdamped. This is not necessarily a practical solution and can be an economically unacceptable approach. On the other hand, however, if overshoot is permissible to some degree for some systems in the case of conventional Serial robots it is still prohibited in the case of Parallel robots as it may easily bring the robot to one of its possible singular configurations, causing damage to the system. This paper introduces a new algorithm for the design of PD controllers that ensures uniform and fast dynamic responses, which are free from overshoots for all robot configurations. The technique also satisfies general stability requirements for the system

Model-Based Policy Search for Automatic Tuning of Multivariate PID Controllers

PID control architectures are widely used in industrial applications. Despite their low number of open parameters, tuning multiple, coupled PID controllers can become tedious in practice. In this paper, we extend PILCO, a model-based policy search framework, to automatically tune multivariate PID controllers purely based on data observed on an otherwise unknown system. The system's state is extended appropriately to frame the PID policy as a static state feedback policy. This renders PID tuning possible as the solution of a finite horizon optimal control problem without further a priori knowledge. The framework is applied to the task of balancing an inverted pendulum on a seven degree-of-freedom robotic arm, thereby demonstrating its capabilities of fast and data-efficient policy learning, even on complex real world problems.Comment: Accepted final version to appear in 2017 IEEE International Conference on Robotics and Automation (ICRA

Fractional PID Control of an Experimental Servo System

This paper investigates the application of fractional-order PID controllers in the velocity control of a servo system. The servo system is controlled by using a real-time digital control system based on MATLAB/Simulink tools. Experimental responses are presented and analyzed, showing the effectiveness of the proposed fractional-order algorithms. Comparison with classical PID controllers is also investigated.N/

Revisiting some practical issues in the implementation of model-free control

International audienceThis paper simplifies several aspects of the practical implementation of the newly introduced model-free control and of the corresponding "intelligent" PID controllers (M. Fliess, C. Join, "Model-free control and intelligent PID controllers: towards a possible trivialization of nonlinear control?," 15th IFAC Symp. System Identif, Saint-Malo, 2009. URL: http://hal.inria.fr/inria-00372325/en/). Four examples with their computer simulations permit to test our techniques