| Popis: |
Naloga prikazuje podrobnejšo eksperimentalno analizo obstoječega krmilnega algoritma za pozicijsko regulacijo hidravlične linearne osi krmiljene z digitalnim piezoventilom, ki predstavlja osnovo za razvoj novega algoritma. Glavni namen naloge je razviti nov koncept krmilnega algoritma in eksperimentalno določiti optimalne parametre, ki bi omogočal bolj stabilno krmiljenje in boljšo ločljivost pozicije batnice hidravličnega valja. Obstoječi krmilni algoritem je zasnovan na osnovi pulzno širinske in pulzno številčne modulacije ter uporabe zaprto-zančnega PID krmiljenja. Po pregledu obstoječega krmilnega algoritma in podrobnejši eksperimentalni analizi smo določili smernice za optimizacijo le-tega. Za potrebe eksperimentov smo dodelali obstoječi krmilni protokol. Zaradi visoke nelinearnosti sistema smo območja referenčne vrednosti pozicije in smer gibanja batnice hidravličnega valja popisali z več različnimi krmilnimi parametri. Tako smo za tri območja pomikov batnice hidravličnega valja določili tri različne kombinacije optimalnih PID parametrov, trojni PID. Rezultati eksperimentalnega dela nam kažejo, da lahko z ustreznimi referenčnimi krmilnimi signali in pravo kombinacijo parametrov PID za posamezno območje pozitivnih in negativnih pomikov, dosežemo ponovljive odzive hidravlične linearne osi in ločljivosti do 1 mikro meter. Raziskave predstavljajo osnovo za razvoj novega krmilnega algoritma v katerega bo vključen nov koncept krmilnega algoritma, to je trojni PID. The paper presents a detailed experimental analysis of the existing control algorithm for positioning of the hydraulic linear axis controlled by a digital piezo valve, which represents the foundation for development of a new control algorithm. Main purpose of our task is development of a new concept of the control algorithm and to experimentally determine optimal control parameters that would allow us to achieve more stable control and better position resolution of the piston rod of the hydraulic cylinder. The base of the existing control algorithm is pulse width and pulse number modulation in combination with closed-loop PID control. A guidelines for its optimization were defined following its overview and detailed experimental analysis. Existing control protocol was altered a bit for the needs of the experiment. Because of the high non-linearity of the system the areas based on the position reference values and the direction of movement of the hydraulic cylinder's piston rod were characterized by several different control parameters. Therefore three different combinations of optimal PID parameters were determined- one for each area of displacement of the piston rod of the hydraulic cylinder- triple PID. The results of the experimental work show that with the appropriate reference control signals and the right combination of PID parameters for a particular range of positive and negative displacements a repeatable responses of the hydraulic linear axis and resolution up to 1 micro meter can be achieved. The research is the basis for the development of a new control algorithm in which a new concept- triple PID- will be included. |
