The application of a new PID autotuning method for the steam/water loop in large scale ships

In large scale ships, the most used controllers for the steam/water loop are still the proportional-integral-derivative (PID) controllers. However, the tuning rules for the PID parameters are based on empirical knowledge and the performance for the loops is not satisfying. In order to improve the control performance of the steam/water loop, the application of a recently developed PID autotuning method is studied. Firstly, a 'forbidden region' on the Nyquist plane can be obtained based on user-defined performance requirements such as robustness or gain margin and phase margin. Secondly, the dynamic of the system can be obtained with a sine test around the operation point. Finally, the PID controller's parameters can be obtained by locating the frequency response of the controlled system at the edge of the 'forbidden region'. To verify the effectiveness of the new PID autotuning method, comparisons are presented with other PID autotuning methods, as well as the model predictive control. The results show the superiority of the new PID autotuning method

Poly Pelletizer: Recycled Pet Pellets From Water Bottles

Plastic water bottles comprise a large amount of waste worldwide. The goal of the Poly Pelletizer project is to create a system that will turn water bottles into polyethylene terephthalate (PET) pellets compatible with extruders to produce 3-D printer lament, along with other recycling applications.The system promotes a sustainable solution to plastic pollution by giving manufactures, particularly in developing nations, the means to produce their own bulk materials using waste plastic. Shrinking industrial recycling processes to a workbench scale gives individuals the ability to convert excess bottles into seemingly limitless products. The system works by using a dual heating and pressure system to both evenly mix and melt the plastic before pushing the resin through a die. The Poly Pelletizer successfully created pellets using various mixtures of virgin PET and shredded water bottles

Dynamics and control of a gas-fired furnace

A non-linear model has been developed for a gas-fired furnace in which oil is heated. The model is applicable from minimum to maximum heat load of the furnace. The dynamics of the model have been compared to experimental results, which were obtained for a pilot-scale furnace. They are in good agreement. A cascade control with feed-forward action has been compared to single feed-back control. Proportional feed-forward action already gives much better results than the latter control

Laser angle sensor development

Electrical and optical parameters were developed for a two axis (pitch/roll) laser angle sensor. The laser source and detector were mounted in the plenum above the model. Two axis optical distortion measurements of flow characteristics in a 0.3 transonic cryogenic tunnel were made with a shearing interferometer. The measurement results provide a basis for estimating the optical parameters of the laser angle sensor. Experimental and analytical information was generated on model windows to cover the reflector. A two axis breadboard was assembled to evaluate different measurement concepts. The measurement results were used to develop a preliminary design of a laser angle sensor. Schematics and expected performance specifications are included

The fractional PID controllers tuned by genetic algorithms for expansion turbine in the cryogenic air separation process

Ovaj rad se bavi realizacijom jednog novog algoritma PID upravljanja zasnovanog na računu necelobrojnog reda (fractional calculus) u proizvodnji tehničkih gasova, odnosno u procesu separacije utečnjenog vazduha. Proizvodnja utečnjenog vazduha niskog pritiska je po prvi put bila uvedena od strane Kapice gde se ekspanzija odvijala u gasnoj turbini. Za primenu u sintezi upravljanja ulazne temperature i protoka vazduha u ekspanzionoj turbini, potrebno je odrediti odgovarajuće diferencijalne jednačine kriogenog procesa mešanja dva gasa na različitim temperaturama na ulazu u ekspanzionu turbinu. Pri tome, odgovarajući model je linearizovan i dekuplovan gde su primenjeni istovremeno klasični PID kao i PIβDα kontroleri necelobrojnog reda da bi se procenio kvalitet predloženog novog upravljanja datim procesom. Skup optimalnih parametara datih kontrolera se postiže primenom optimizacione procedure bazirane na genetskim algoritmima minimizovanjem odgovarajućeg kriterijuma optimalnosti. Naš metod se fokusira u okviru kriterijuma optimalnosti na smanjenje preskoka, vreme smirenja i minimizaciju integralne greške. Simulacije sprovedene u vremenskom domenu pokazuju bolje performance optimalnog PIβDα kontrolera u odnosu na klasični optimalni PID kontroler.This paper deals with the design of a new algorithm of PID control based on fractional calculus (FC) in production of technical gases, i.e. in a cryogenic air separation process. Production of low pressure liquid air was first introduced by P.L. Kapitsa and involved expansion in a gas turbine. For application in the synthesis of the control law, for the input temperature and flow of air to the expansion turbine, it is necessary to determine the appropriate differential equations of the cryogenic process of mixing of two gaseous airflows at different temperatures before entrance to the expansion turbine. Thereafter, the model is linearized and decoupled and consequently classical PID and fractional order PIβDα controllers are taken to assess the quality of the proposed technique. A set of optimal parameters of these controllers are achieved through the genetic algorithm optimization procedure by minimizing a cost function. Our design method focuses on minimizing performance criterion which involves IAE, overshoot, as well as settling time. A time-domain simulation was used to identify the performance of PIβDα controller with respect to a traditional optimized PID controller

The fractional PID controllers tuned by genetic algorithms for expansion turbine in the cryogenic air separation process

Ovaj rad se bavi realizacijom jednog novog algoritma PID upravljanja zasnovanog na računu necelobrojnog reda (fractional calculus) u proizvodnji tehničkih gasova, odnosno u procesu separacije utečnjenog vazduha. Proizvodnja utečnjenog vazduha niskog pritiska je po prvi put bila uvedena od strane Kapice gde se ekspanzija odvijala u gasnoj turbini. Za primenu u sintezi upravljanja ulazne temperature i protoka vazduha u ekspanzionoj turbini, potrebno je odrediti odgovarajuće diferencijalne jednačine kriogenog procesa mešanja dva gasa na različitim temperaturama na ulazu u ekspanzionu turbinu. Pri tome, odgovarajući model je linearizovan i dekuplovan gde su primenjeni istovremeno klasični PID kao i PIβDα kontroleri necelobrojnog reda da bi se procenio kvalitet predloženog novog upravljanja datim procesom. Skup optimalnih parametara datih kontrolera se postiže primenom optimizacione procedure bazirane na genetskim algoritmima minimizovanjem odgovarajućeg kriterijuma optimalnosti. Naš metod se fokusira u okviru kriterijuma optimalnosti na smanjenje preskoka, vreme smirenja i minimizaciju integralne greške. Simulacije sprovedene u vremenskom domenu pokazuju bolje performance optimalnog PIβDα kontrolera u odnosu na klasični optimalni PID kontroler.This paper deals with the design of a new algorithm of PID control based on fractional calculus (FC) in production of technical gases, i.e. in a cryogenic air separation process. Production of low pressure liquid air was first introduced by P.L. Kapitsa and involved expansion in a gas turbine. For application in the synthesis of the control law, for the input temperature and flow of air to the expansion turbine, it is necessary to determine the appropriate differential equations of the cryogenic process of mixing of two gaseous airflows at different temperatures before entrance to the expansion turbine. Thereafter, the model is linearized and decoupled and consequently classical PID and fractional order PIβDα controllers are taken to assess the quality of the proposed technique. A set of optimal parameters of these controllers are achieved through the genetic algorithm optimization procedure by minimizing a cost function. Our design method focuses on minimizing performance criterion which involves IAE, overshoot, as well as settling time. A time-domain simulation was used to identify the performance of PIβDα controller with respect to a traditional optimized PID controller