PID stabilization of MIMO plants

Cataloged from PDF version of article.Closed-loop stabilization using proportional–integral–derivative (PID) controllers is investigated for linear multiple-input–multiple-output (MIMO) plants. General necessary conditions for existence of PID-controllers are derived. Several plant classes that admit PID-controllers are explicitly described. Plants with only one or two unstable zeros at or “close” to the origin (alternatively, at or close to infinity) as well as plants with only one or two unstable poles which are at or close to origin are among these classes. Systematic PID-controller synthesis procedures are developed for these classes of plants

Fuzzy control applied to an electrical power generation system mounted on tractors for driving of agricultural implements

CAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORThe demand of the agricultural sector for more operationally efficient machines and implements motivated the development of alternatives for driving of this equipment. Aiming an electrical supply to apply in agricultural implements, this study proposes a system that uses the tractor power take off to activate a synchronous generator, using a fuzzy logic controller designed to regulate the generated voltage level. Different control architectures were tested and evaluated by simulations. In the initial stage were evaluated fuzzy PI, fuzzy PD and fuzzy PID controllers of multiple inputs and single output (MISO) and the error of the generated voltage as state variable. Subsequently, it was evaluated a fuzzy PI controller of single input and multiple outputs (SIMO) with a modified rule base for the system. In the final stage, the angular drive speed was included as state variable of the controller. The behavior of each architecture was analyzed by means of performance indexes. The results show that among the tested controllers, the modified fuzzy PI SIMO presented the best performance values while maintaining the operating variables within the established limits.The demand of the agricultural sector for more operationally efficient machines and implements motivated the development of alternatives for driving of this equipment. Aiming an electrical supply to apply in agricultural implements, this study proposes a365846857CAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORsem informaçã

Mixed H2/H∞ robust controllers in aircraft control problem

A leading cause of accidents during the landing phase of a flight lies in a considerable altitude loss by an aircraft as a result of the impact of a microburst of wind. One of the significant factors focuses primarily on the need to simultaneously satisfy various requirements regarding conditions of environmental disturbances and a wide range of systemic changes. The paper presents an algorithm for synthesizing an optimal controller that solves the mixed H2/H∞ control problem for the stabilization of aircraft in glide-path landing mode in the presence of uncertainty. Firstly, the principles of multi-criteria optimization are presented, and the mixed H2/H∞ problem is interpreted as the synthesis of a system with optimal quadratic performance, subject to its readiness to operate with the worst disturbance. Then, the ensuing section expounds upon the mathematical depiction of the vertical trajectory of aircraft, duly considering the perturbations imposed by wind phenomena. Subsequently, the effectiveness of mixed H2/H∞ control is confirmed compared to autonomous H2 or H∞ regulators through simulation outcomes acquired from the created system. Optimization based on a hybrid (mixed) criterion allowed combining the strengths of locally optimal systems based only on H2 or H∞ theory

Switch actuators in process control: constraint problems and corrections

The paper deals with switch actuators in process control. The inclusion of a signal modulator required for commanding the actuator in proportional-integral-derivative (PID) controller structures is discussed. In particular, it is analysed how the restrictions of this modulator may worsen the well-known problems of process-input saturation, such as windup or loss of control directionality among others. From this analysis a simple correction methodology is proposed for simultaneously addressing constraints in both modulator and actuator. This methodology is easily implemented from feeding back a modulator signal and takes advantage of the wide knowledge existing in anti-windup techniques. Two examples (SISO and MIMO) are presented to assess the effectiveness of the proposed correction.Instituto de Investigaciones en Electrónica, Control y Procesamiento de Señale

Switch actuators in process control: constraint problems and corrections

The paper deals with switch actuators in process control. The inclusion of a signal modulator required for commanding the actuator in proportional-integral-derivative (PID) controller structures is discussed. In particular, it is analysed how the restrictions of this modulator may worsen the well-known problems of process-input saturation, such as windup or loss of control directionality among others. From this analysis a simple correction methodology is proposed for simultaneously addressing constraints in both modulator and actuator. This methodology is easily implemented from feeding back a modulator signal and takes advantage of the wide knowledge existing in anti-windup techniques. Two examples (SISO and MIMO) are presented to assess the effectiveness of the proposed correction.Instituto de Investigaciones en Electrónica, Control y Procesamiento de Señale