Modelling and optimisation of anthropomorphic soft robotic hand

U ovome radu dan je kratki uvid u područje mekane robotike. Definiran je pojam mekanog pneumatskog aktuatora koji će biti glavni tip aktuatora u modeliranju mekane antropomorfne robotske šake. Odabrani materijal za izradu šake prvo je testiran. Testiranje je izvedeno u Laboratoriju za eksperimentalnu mehaniku Fakulteta strojarstva i brodogradnje u Zagrebu. Uzorci materijala Filaflex60A testirani su vlačnim ispitivanjem na kidalici, nakon čega su podaci obrađeni u Excelu, kako bi se dobile prvotne krivulje naprezanja-istezanja za svaki uzorak. Nakon toga ti podaci su učitani u MATLAB gdje su obrađeni na način da se dobije ukupna srednja vrijednost naprezanja-istezanja. Potom su vrijednosti dobivene MATLAB analizom unesene u Abaqus, gdje su za krivulju naprezanja-istezanja ukupne srednje vrijednosti proračunati koeficijenti modela hiperelastičnih materijala. Nakon toga u Solidworksu je napravljen osnovni oblik pneumatskog aktuatora. Taj pneumatski aktuator učitan je u Abaqus, pri čemu su za definiranje materijala iskorišteni koeficijenti hiperelastičnog materijala dobiveni analizom podataka. Model je potom opterećen gravitacijskom silom i pritiskom zraka od 30 KPa. Dobiveni rezultati simulacije uspoređeni su sa stvarnim modelom, za ista opterećenja. Definirani su osnovni kriteriji za dizajniranje antropomorfne ljudske šake. Opisano je kako su postavljeni kriteriji funkcionalnosti usmjerili dizajn. Opisan je proces dizajniranja idejnog koncepta antropomorfne robotske šake. Dana je analiza gotovog funkcionalnog modela šake te su na temelju tih spoznaja dani neki komentari za daljnje poboljšanja dizajna u smjeru produljivanja vijeka upotrebe same šake kao i njene funkcije.This paper will give a brief insight into the field of soft robotics. It will define the term soft pneumatic actuator, which will be the main type of actuator used in modelling an anthropomorphic soft robotic fist. The selected material for manufacturing the soft robotic fist was first tested. Testing was performed at the Laboratory for Experimental Mechanics of the Faculty of Mechanical Engineering and Naval Architecture in Zagreb. Samples of Filaflex60A material were tested by a tensile testing machine, after which the data was firstly processed in Excel, to obtain the initial stress-strain curves for each sample. These data sets were then loaded into MATLAB, where they were further processed so that a mean stress-strain curve of the tested values can be obtained. The values obtained by the MATLAB analysis were then uploaded into Abaqus, where the coefficients of the hyperplastic material model were calculated for the values of the uploaded mean stress-strain curve. After that, the basic shape of the pneumatic actuator was designed in Solidworks. This pneumatic actuator was then loaded into Abaqus, and the coefficients of the hyperplastic material model, calculated in the previous analysis, were used to define its material properties. The simulated model is then subjected to the gravitational force and air pressure, in the value of 30 KPa is applied to the inner cavities of the model. The obtained simulation results were compared with a manufactured model, for the same loads. Basic criteria for designing an anthropomorphic human fist is defined. It is described how the set of functionality criteria guided the design in the way it has. The process of designing the conceptual model of an anthropomorphic robotic fist is described. An analysis of the finished functional model of the fist is given and based on these findings, some comments are given for further design improvements with the aim of extending the service life of the fist, as well as its function