Vibration suppression in multi-body systems by means of disturbance filter design methods

This paper addresses the problem of interaction in mechanical multi-body systems and shows that subsystem interaction can be considerably minimized while increasing performance if an efficient disturbance model is used. In order to illustrate the advantage of the proposed intelligent disturbance filter, two linear model based techniques are considered: IMC and the model based predictive (MPC) approach. As an illustrative example, multivariable mass-spring-damper and quarter car systems are presented. An adaptation mechanism is introduced to account for linear parameter varying LPV conditions. In this paper we show that, even if the IMC control strategy was not designed for MIMO systems, if a proper filter is used, IMC can successfully deal with disturbance rejection in a multivariable system, and the results obtained are comparable with those obtained by a MIMO predictive control approach. The results suggest that both methods perform equally well, with similar numerical complexity and implementation effort

Consciosusness in Cognitive Architectures. A Principled Analysis of RCS, Soar and ACT-R

This report analyses the aplicability of the principles of consciousness developed in the ASys project to three of the most relevant cognitive architectures. This is done in relation to their aplicability to build integrated control systems and studying their support for general mechanisms of real-time consciousness.\ud To analyse these architectures the ASys Framework is employed. This is a conceptual framework based on an extension for cognitive autonomous systems of the General Systems Theory (GST).\ud A general qualitative evaluation criteria for cognitive architectures is established based upon: a) requirements for a cognitive architecture, b) the theoretical framework based on the GST and c) core design principles for integrated cognitive conscious control systems

ANTI-SWING CONTROLLER OF 3D CRANE

Crane control is frequently studied where anti-swing control of the load has been one of the important issues. It is important to have anti-swing control for a crane because the swing motion of the suspended payload results in many problems to the productivity and safety. Modeling and control of a crane is a long-time research interest. Many researchers have worked on this issue of anti-swing control of the crane system. Their work can be divided into largely two groups: open loop and closed loop control. This project focuses on the development of anti-swing control for the crane. Several controllers will be studied, let it be open loop system and closed loop system for the anti-swing control. The simulation of the 3DCrane is done using MATLAB and RTWT toolbox package. This report detailed the mathematical modelling of the crane system and the model verification. The model of the crane system is developed using Lagrangian dynamics and electromechanical theory. In this report it is shown that a crane system can be represented as two sub models which are coupled by a term which includes the rope length as a parameter. The model is verified as an accurate model of a crane system and it is used to simulate performance of controllers using Matlab. Two types of controllers have been designed in this project which is PD controller and full state feedback (FSF) using pole placement method. The performance of the controllers is discussed and it is proven that the controllers have given a good control on the position of the cart and reduces the swing of the load

Model-based versus model-free control designs for improving microalgae growth in a closed photobioreactor: Some preliminary comparisons

Controlling microalgae cultivation, i.e., a crucial industrial topic today, is a challenging task since the corresponding modeling is complex, highly uncertain and time-varying. A model-free control setting is therefore introduced in order to ensure a high growth of microalgae in a continuous closed photobioreactor. Computer simulations are displayed in order to compare this design to an input-output feedback linearizing control strategy, which is widely used in the academic literature on photobioreactors. They assess the superiority of the model-free standpoint both in terms of performances and implementation simplicity.Comment: The 24th Mediterranean Conference on Control and Automation (MED'16), Athens, Greece (June 21-24, 2016

Monitoring and Control of Pressure in a Gas Plant via PID plus Feedforward Controller

This project is about the development of a controller for a process using well-established advanced process control (APC) algorithm; mainly PID and Feedforward controls. This work focuses on a model of a process that would be used for investigation of the effectiveness of several control strategies towards effective control in overcoming disturbances in the plant. The controller is observed to see how well a variable can be manipulated and controlled in real-time implementation. However, it is well known that the performances of these controllers much depend on the appropriate implementation of additional functionalities such as anti-windup and feedforward, for example, in addition to the tuning of PID parameters. The process targeted is a gas process and it mainly focused on pressure and flow control of a gaseous pilot plant. To execute the overall simulation, the controller is built on MATLAB/Simulink/LabVIEW which is a technical computing program that has easily adaptable structure where control strategies and model variables can be modified. It is shown in the results of simulation and performance analysis of both controller and process that the PID plus Feedforward control could substantially improve control performance with implementation of a model error. The PID controller provides the needed reaction to the process variable to reach steady state during setpoint changes and disturbances while the feedforward element manages to fully eliminate the effects of disturbance injection without causing too much disruption to the process response

Genetic Algorithms Based Approach for Designing Spring Brake Orthosis – Part Ii: Control of FES Induced Movement

Spring brake orthotic swing phase for paraplegic gait is initiated through releasing the brake on the knee mounted with a torsion spring. The stored potential energy in the spring, gained from the previous swing phase, is solely responsible for swing phase knee flexion. Hence the later part of the SBO operation, functional electrical stimulation (FES) assisted extension movement of the knee has to serve an additional purpose of restoring the spring potential energy on the fly. While control of FES induced movement as such is often a challenging task, a torsion spring, being antagonistically paired up with the muscle actuator, as in spring brake orthosis (SBO), only adds to the challenge. Two new schemes are proposed for the control of FES induced knee extension movement in SBO assisted swing phase. Even though the control schemes are closed-loop in nature, special attention is paid to accommodate the natural dynamics of the mechanical combination being controlled (the leg segment) as a major role playing feature. The schemes are thus found to be immune from some drawbacks associated with both closed-loop tracking as well as open-loop control of FES induced movement. A leg model including the FES knee joint model of the knee extensor muscle vasti along with the passive properties is used in the simulation. The optimized parameters for the SBO spring are obtained from the earlier part of this work. Genetic algorithm (GA) and multi-objective GA (MOGA) are used to optimize the parameters associated with the control schemes with minimum fatigue as one of the control objectives. The control schemes are evaluated in terms of three criteria based on their ability to cope with muscle fatigue

Teaching Control Principles to Industry Practitioners

This paper addresses the need of continued education of process industry practitioners such as operators and instrumentation engineers. The process industry regulatory control tuning situation of today is reviewed. Areas of potential improvement are identified. A course, aimed at fulfilling these needs is presented. Especially, useful laboratory experiments are outlined. The suggested course was given within PICLU – a regional collaboration between academia and process industry in Scandinavia