Configuration-based compliance control of kinematically redundant robot arm Part I: Theoretical framework

Kada je popustljivost vrha robota dominantno određena popustljivošću njegovih zglobova, generalizovana matrica krutosti robota može se preslikati iz prostora radnog zadatka u prostor unutrašnjih koordinata robota primenom kongruentne transformacije. Generisana na ovaj način, matrica krutosti u unutrašnjim koordinatama je u opštem slučaju nedijagonalna. Nedijagonalni elementi se mogu generisati samo redundantnom aktuacijom (poliartikulacioni aktuatori). Mada je ova vrsta aktuatora široko rasprostranjena kod bioloških sistema, njena praktična primena kod robota i sličnih veštačkih sistema je ekstremno problematična. Da bi se prevazišao ovaj problem, predlaže se rešenje bazirano na kinematskoj redundansi. U okviru ovog rada koji se sastoji iz dva dela, prikazuje se novi pristup upravljanja popustljivošću vrha robota, odnosno elastomehaničkom interakcijom vrha robota i njegovog okruženja, primenom kinematske redundanse umesto aktuacione. U prvom delu ovaj pristup je prikazan kroz koncipiranje metode upravljanja krutošću promenom konfiguracije (CSC) za slučaj kinetosatičke konzistentnosti, primenom projekcije gradijenta optimizacione funkcije koja minimizira Euklidovu normu nedijagonalnih elemenata matrice krutosti robota izražene u unutrašnjim koordinatama.When the robot endpoint compliance is dominantly influenced by the flexibility of its joints, the robot taskspace generalized stiffness matrix can be mapped onto jointspace using appropriate congruence transformation. Thus produced, the jointspace stiffness matrix is generally nondiagonal. Off-diagonal elements can be generated by redundant actuation only (polyarticular actuators). Although this kind of actuation is widely present in biological systems, its practical implementation in engineering systems is very difficult. To overcome this problem, use of kinematic redundancy is proposed. This two-part paper presents an approach to the control of robot endpoint compliance, i.e., elasto-mechanical interaction between a robot and its environment using kinematic redundancy instead of actuation redundancy. In Part I this approach is developed by proposing the Configuration-based Stiffness Control (CSC) method for kinetostatically consistent control of robot compliant behaviour, based on the gradient projection of the cost function which minimizes the norm of off-diagonal elements of the jointspace matrix

Current-voltage characteristics of carbon nanotube FETS

U ovom radu ispitivane su karakteristike FETova izrađenih na bazi ugljeničnih nanotuba (CNT FETova). U prvom delu rada, predstavljene su neke osnovne osobine ugljeničnih nanotuba. Zatim je razvijen analitički model strujno-naponskih karakteristika CNT FETova koji dobro opisuje ponašanje ove savremene nanoelektronske naprave. Na bazi predloženog modela urađene su simulacije. Dobijeni rezultati su u saglasnosti sa prethodno publikovanim. .In this paper, one of the most actual devices - carbon nanotube field effect transistor (CNT FET) is investigated. At the beginning, the nanotube properties are presented. The main contribution of this paper is the new analytical model of CNT FET current-voltage characteristics. Developed model describes behavior of CNT FET in very good manner and, at the same time, the model is relatively simple. Using the developed model, simulations were performed. The results obtained by using proposed model are in very good agreement with already known and published ones.

Ergonomic and electronic designing of muscle stimulator

U radu je predloženo jedno novo rešenje za mišićni stimulator. Uređaj je programabilan, može se jednostavno podešavati od strane lekara, kao i od strane pacijenta. Dizajnersko rešenje ovog mišićnog stimulatora poseduje unapređeni interfejs. Uređaj je bezbedan za upotrebu i poseduje određena ergonomska poboljšanja. Ovaj mišićni stimulator je malih dimenzija i male težine. Predlog hardverskog rešenja uključuje korišćenje jedne od najsavremenijih elektronskih komponenti MOSFET-a, izrađenog na bazi silicijum-karbida. Uređaj ima malu potrošnju. Stimulator ima odlične elektronske karakteristike, a u isto vreme je pogodniji za rukovanje i upotrebu od postojećih. Prezentovana dizajnerska rešenja takođe imaju pozitivan uticaj na ekonomsku opravdanost primene ovog uređaja.The paper proposes a new ergonomic and electronic solution for the muscle stimulator. The device is programmable. It can be easily adjusted by the doctor, as well as by the patient. The design solution of this muscle stimulator has the improved interface. The device is safe to use and has determined ergonomic improvements. This muscle stimulator has small dimensions and light weight. The proposal includes a hardware solution using one of the most advanced electronic components MOSFET created on the basis of silicon carbide. The device has a low consumption. The stimulator has excellent electronic properties, while at the same time it is more suitable for handling and use in relation to existing ones. Presented design solutions also have a positive impact on the economic justification for the application of this device

Current-voltage characteristics of carbon nanotube FETS

U ovom radu ispitivane su karakteristike FETova izrađenih na bazi ugljeničnih nanotuba (CNT FETova). U prvom delu rada, predstavljene su neke osnovne osobine ugljeničnih nanotuba. Zatim je razvijen analitički model strujno-naponskih karakteristika CNT FETova koji dobro opisuje ponašanje ove savremene nanoelektronske naprave. Na bazi predloženog modela urađene su simulacije. Dobijeni rezultati su u saglasnosti sa prethodno publikovanim. .In this paper, one of the most actual devices - carbon nanotube field effect transistor (CNT FET) is investigated. At the beginning, the nanotube properties are presented. The main contribution of this paper is the new analytical model of CNT FET current-voltage characteristics. Developed model describes behavior of CNT FET in very good manner and, at the same time, the model is relatively simple. Using the developed model, simulations were performed. The results obtained by using proposed model are in very good agreement with already known and published ones.

Moving between two paradigms - Sociocultural approach to research of conspiracy theories

Social sciences and humanistic disciplines that showed an interest in conspiracy theories are dominantly relying on either a cultural perspective (e.g. history, anthropology, ethnology, sociology, cultural studies, literature, etc.) or a positivistic perspective (psychology and political science). Between these two perspectives lays a gap in the way the nature of the phenomenon is understood, as well as its manifestation, the methodology used and how they interpret results and their implications. In this paper we are aiming to show that this topic is in its core a sociocultural question and that the perspective of sociocultural theory represents a way to bridge the aforementioned gap by using features of both approaches. If the cultural approach sees conspiracy theories as a product of a culture, and the positivistic approach as a question of the individual, then through a sociocultural perspective we are looking at how an individual actively acts in a society which developed the discourse of conspiracy theories through time. By adopting this view, we can study how individuals purposefully participate in contextually situated (co-)construction and transformation of meanings, discourse and conspiratorial narratives, as well as how they utilize conspiracy theories and other artifacts

Gospodarske karakteristike klonskih kandidata Graševine izabranih u postupku individualne klonske selekcije

Individualna klonska selekcija vinove loze je postupak kojim se iz populacije pojedine sorte nastoje izdvojiti genotipovi (klonovi) kod kojih je došlo do mutacija koje su rezultirale pozitivnim promjenama nekih od gospodarski važnih karakteristika. Izdvajanje klonova provodi se na temelju višegodišnjeg ispitivanja klonskih linija u ujednačenim uvjetima pokusnog nasada. Graševina je najvažnija sorta vinove loze u Hrvatskoj kod koje je postupak klonske selekcije započeo 2004. godine, a 2007. godine podignuti su pokusni nasadi za provođenje individualne klonske selekcije tj. ispitivanje najvažnijih gospodarskih karakteristika klonskih linija. Cilj ovog rada je provesti analizu rezultata četverogodišnjeg ispitivanja klonskih kandidata sorte Graševina i izdvojiti one kod kojih su potvrđene pozitivne promjene određenih gospodarski važnih svojstava s ciljem pokretanja postupka registracije klonova ove sorte. U ovom radu praćenjem klonova došli smo do rezultat koji pokazuju da postoji značajna unutar sortna varijabilnost i da na osnovu nje možemo izdvojiti nekoliko klonova koji su nam bitni po svojim gospodarskim karakteristikama. Gospodarske karakteristike kojima smo se vodili su prinos, sadržaj kiselina i sadržaj šećera te prosječna masa grozda.Individual clonal selection of grapevine is the process by which the population of certain varieties tend to isolate genotypes (clones) in which there has been a mutation that resulted in positive changes in some of the economically important characteristics. Isolation of clones is carried out on the basis of many years of testing clonal lines in equal conditions experimental plantation. Graševina is the most important grape variety in Croatia, where the clonal selection process started in 2004 and 2007 have been raised guinea plantations enforcement individual clonal selection. Examination of the most important economic characteristics of clonal lines. The aim of this paper is an analysis of results four tests clonal candidates varieties Graševine and allocate those in which they confirmed the positive changes of certain economically important characteristics in order to initiate the registration process clones of this variety. In this paper following the clones we have reached a result that shows that there is considerable variability within varieties and based on it we can extract several clones that are important to us for their economic characteristics. Economic characteristics which we are led by yield, acidity and sugar content and average weight of the bunch

Gospodarske karakteristike klonskih kandidata Graševine izabranih u postupku individualne klonske selekcije

Individualna klonska selekcija vinove loze je postupak kojim se iz populacije pojedine sorte nastoje izdvojiti genotipovi (klonovi) kod kojih je došlo do mutacija koje su rezultirale pozitivnim promjenama nekih od gospodarski važnih karakteristika. Izdvajanje klonova provodi se na temelju višegodišnjeg ispitivanja klonskih linija u ujednačenim uvjetima pokusnog nasada. Graševina je najvažnija sorta vinove loze u Hrvatskoj kod koje je postupak klonske selekcije započeo 2004. godine, a 2007. godine podignuti su pokusni nasadi za provođenje individualne klonske selekcije tj. ispitivanje najvažnijih gospodarskih karakteristika klonskih linija. Cilj ovog rada je provesti analizu rezultata četverogodišnjeg ispitivanja klonskih kandidata sorte Graševina i izdvojiti one kod kojih su potvrđene pozitivne promjene određenih gospodarski važnih svojstava s ciljem pokretanja postupka registracije klonova ove sorte. U ovom radu praćenjem klonova došli smo do rezultat koji pokazuju da postoji značajna unutar sortna varijabilnost i da na osnovu nje možemo izdvojiti nekoliko klonova koji su nam bitni po svojim gospodarskim karakteristikama. Gospodarske karakteristike kojima smo se vodili su prinos, sadržaj kiselina i sadržaj šećera te prosječna masa grozda.Individual clonal selection of grapevine is the process by which the population of certain varieties tend to isolate genotypes (clones) in which there has been a mutation that resulted in positive changes in some of the economically important characteristics. Isolation of clones is carried out on the basis of many years of testing clonal lines in equal conditions experimental plantation. Graševina is the most important grape variety in Croatia, where the clonal selection process started in 2004 and 2007 have been raised guinea plantations enforcement individual clonal selection. Examination of the most important economic characteristics of clonal lines. The aim of this paper is an analysis of results four tests clonal candidates varieties Graševine and allocate those in which they confirmed the positive changes of certain economically important characteristics in order to initiate the registration process clones of this variety. In this paper following the clones we have reached a result that shows that there is considerable variability within varieties and based on it we can extract several clones that are important to us for their economic characteristics. Economic characteristics which we are led by yield, acidity and sugar content and average weight of the bunch

Gospodarske karakteristike klonskih kandidata Graševine izabranih u postupku individualne klonske selekcije

Individualna klonska selekcija vinove loze je postupak kojim se iz populacije pojedine sorte nastoje izdvojiti genotipovi (klonovi) kod kojih je došlo do mutacija koje su rezultirale pozitivnim promjenama nekih od gospodarski važnih karakteristika. Izdvajanje klonova provodi se na temelju višegodišnjeg ispitivanja klonskih linija u ujednačenim uvjetima pokusnog nasada. Graševina je najvažnija sorta vinove loze u Hrvatskoj kod koje je postupak klonske selekcije započeo 2004. godine, a 2007. godine podignuti su pokusni nasadi za provođenje individualne klonske selekcije tj. ispitivanje najvažnijih gospodarskih karakteristika klonskih linija. Cilj ovog rada je provesti analizu rezultata četverogodišnjeg ispitivanja klonskih kandidata sorte Graševina i izdvojiti one kod kojih su potvrđene pozitivne promjene određenih gospodarski važnih svojstava s ciljem pokretanja postupka registracije klonova ove sorte. U ovom radu praćenjem klonova došli smo do rezultat koji pokazuju da postoji značajna unutar sortna varijabilnost i da na osnovu nje možemo izdvojiti nekoliko klonova koji su nam bitni po svojim gospodarskim karakteristikama. Gospodarske karakteristike kojima smo se vodili su prinos, sadržaj kiselina i sadržaj šećera te prosječna masa grozda.Individual clonal selection of grapevine is the process by which the population of certain varieties tend to isolate genotypes (clones) in which there has been a mutation that resulted in positive changes in some of the economically important characteristics. Isolation of clones is carried out on the basis of many years of testing clonal lines in equal conditions experimental plantation. Graševina is the most important grape variety in Croatia, where the clonal selection process started in 2004 and 2007 have been raised guinea plantations enforcement individual clonal selection. Examination of the most important economic characteristics of clonal lines. The aim of this paper is an analysis of results four tests clonal candidates varieties Graševine and allocate those in which they confirmed the positive changes of certain economically important characteristics in order to initiate the registration process clones of this variety. In this paper following the clones we have reached a result that shows that there is considerable variability within varieties and based on it we can extract several clones that are important to us for their economic characteristics. Economic characteristics which we are led by yield, acidity and sugar content and average weight of the bunch

Compliant behaviour of redundant robot arm: Experiments with null-space

This paper presents theoretical and experimental aspects of Jacobian nullspace use in kinematically redundant robots for achieving kinetostatically consistent control of their compliant behavior. When the stiffness of the robot endpoint is dominantly influenced by the compliance of the robot joints, generalized stiffness matrix can be mapped into joint space using appropriate congruent transformation. Actuation stiffness matrix achieved by this transformation is generally nondiagonal. Off-diagonal elements of the actuation matrix can be generated by redundant actuation only (polyarticular actuators), but such kind of actuation is very difficult to realize practically in technical systems. The approach of solving this problem which is proposed in this paper is based on the use of kinematic redundancy and nullspace of the Jacobian matrix. Evaluation of the developed analytical model was done numerically by a minimal redundant robot with one redundant d.o.f. and experimentally by a 7 d.o.f. Yaskawa SIA 10F robot arm

Softversko rešenje za određivanje čitljivosti analognih vizuelnih pokazivača sa kružnom skalom

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