Publications

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Authors: A manipulator that is performing a manoeuvre generates reaction forces and torques that dynamically load the supporting base. A special interest in the control of the base reactions arises for robots mounted on a moving base, due to the interaction between the motion of the manipulator and the motion of the base itself, which in many cases needs to be controlled at the same time. In this paper the problem of tracking an arbitrary base reaction profile is considered. The present work gives a contribution to the subject of the kinematic control of spacecraft mounted manipulators and their dynamical effects in terms of reaction forces and torques, and can be used for the development of centralized control systems aimed at controlling multiple robots mounted on the same spacecraft, where a non-operating manipulator can cooperate to compensate the disturbances generated by a second operating robot, together with the reaction control system actuators. The solution to the problem is given in the form of a kinematic law for the joint variables of the manipulator, and the joint acceleration trajectories related to the desired base reaction profile are obtained. Furthermore, the influence of the degree of redundancy of the robot is analyzed, with respect both to the kinematic and the dynamic tasks. The availability of the redundancy can be exploited in order to prescribe a desired trajectory to the end-effector, and specifically the problem of realizing a defined base reaction profile and in the meantime achieve the best approximation of an end-effector trajectory is considered. The proposed solutions are developed in terms of pseudoinverse formulations, and the reaction control problems are set in local optimization form, leading to the definition of constrained least squares problems. The implementation of the proposed kinematic schemes in a robot simulator allowed to test the capabilities of the proposed concepts. Pretto; Cocuzza; Debei

Journal: 2009

Published: title_year

DOI: 358995151

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Authors: The control of the reactions exerted on the base spacecraft during manipulator operations is an important issue in space robotics applications, because it leads to reduced energy consumption of the Attitude Control System, thus extending the operating life of the entire system. This paper presents two novel redundancy resolution schemes aimed at locally minimizing the reaction torque transferred to the spacecraft during manipulator manoeuvres. The first presented solution is based on a weighted Jacobian pseudoinverse and is derived by using Lagrangian multipliers. The second one is based on a least squares formulation of the minimization problem. A closed-form solution is derived for both the presented methods, and their equivalence is proven analytically. Moreover, the proposed solutions, which are suitable for real-time implementation, are extended in order to take into account the physical limits of the manipulator joints. A software simulator has been developed in order to simulate the performance of the presented solutions for the selected test cases. The proposed solutions have then been experimentally tested using a 3D free-flying robot previously tested in an ESA Parabolic Flight Campaign. In the test campaign the 3D robot has been converted in a 2D robot thanks to its modularity in order to perform planar tests, in which the microgravity environment can be simulated without time constraints. Air-bearings are used to sustain the links weight, and a dynamometer is used to measure the reaction torque. The experimental validation of the presented inverse kinematics solutions, with an insight on the effect of joint flexibility on their performance, has been carried out, and the experimental results confirmed the good performance of the proposed methods. The solution is then validated in the case of a planar three degrees of freedom free-floating manipulator by using a software simulator, and the requirements on the maximum joint variables of a free-floating and of a fixed-based robot with the same configuration are compared for a given task. Finally, the study of the workspace in which a zero reaction torque can be obtained is performed for different base/arm mass ratios, both taking into account the physical joint limits or not. Cocuzza; Pretto; Debei

Journal: 2010

Published: Cocuzza S.; Pretto I.; Debei S.

DOI: 361984804

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Authors: Celesti-Grapow, L; Alessandrini, A; Arrigoni, PV; Assini, S; Banfi, E; Barni, E; Bovio, M; Brundu, G; Cagiotti, MR; Camarda, I; Carli, E; Conti, F; Del Guacchio, E; Domina, G; Fascetti, S; Galasso, G; Gubellini, L; Lucchese, F; Medagli, P; Passalacqua, NG; Peccenini, S; Poldini, L; Pretto, F; Prosser, F; Vidali, M; Viegi, L; Villani, MC; Wilhalm, T; Blasi, C; Dept Plant Biol; Dept Plant Biol; Dept Landscape Ecol; Dept Bot Ecol & Geol; Dept Appl Biol; Dept Environm Sci; Dept Bot; Dept Biol; Bot Garden; Dept Landscape Study; Dept Life Sci; In this paper, we provide an overview of the distribution and invasive status of non-native species in the Italian flora across its administrative regions, biogeographic regions and main land use types, and a synthesis of current knowledge on the threats they pose within the country. The information on non-native plant species collected during the project "A survey of the non-native Italian flora" was used to compile comprehensive regional and national databases. The number of nonnative species within a given administrative region increases in proportion to its size, resident population density and latitude, reaching the highest values in the intensively cultivated, heavily industrialized and urbanized Po Plain in northern Italy. The number of casual species is positively correlated with the number of yearly visitors in each region and negatively correlated with the proportion of mountainous terrain within the region. If compared with the Continental and Mediterranean biogeographic regions, the Alpine region yields the lowest number of non-native species and lowest proportion of casual species. The number and density of introduced species is highest in artificial land use types, particularly in urban areas. A negative impact is reported to be exerted by 203 species, most of which are agricultural weeds. © 2010 Societ̀ Botanica Italiana. Celesti-Grapow; Alessandrini; Arrigoni; Assini; Banfi; Barni; Bovio; Brundu; Cagiotti; Camarda; Carli; Conti; del Guacchio; Domina; Fascetti; Galasso; Gubellini; Lucchese; Medagli; Passalacqua; Peccenini; Poldini; Pretto; Prosser; Vidali; Viegi; Villani; Wilhalm; Blasi

Journal: English

Published: doi

DOI: WOS:000277672800002

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Volume: PLANT BIOSYSTEMS###1126-3504 Pages: 28-Non-native flora of Italy: Species distribution and threats

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Authors: Non assegn

Journal: Mimesis

Published: title_year

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Authors: Cocuzza, S; Pretto, I; Debei, S; CISAS G Colombo Ctr Studies & Activ Space; CISAS G Colombo Ctr Studies & Activ Space; Deparment Mech Engn; This paper presents the theoretical formulation and the experimental validation of a novel solution for the inverse kinematics of redundant space robotic systems aimed at locally minimizing the torque transferred to the spacecraft due to the robotic arm movement. The differential kinematics is formulated at the acceleration level and an additional constraint is imposed in order to locally minimize the torque transferred to the spacecraft center of mass. This problem can be expressed as a constrained linear least squares problem and a closed-form solution is obtained. An extension of this method is presented in order to take into account the physical limits of the manipulator, by limiting the joint accelerations under acceptable values. In this case the problem can be expressed as a constrained linear least squares problem with both equality and inequality constraints. The proposed solution has been experimentally tested using a 3D free-flying robot previously tested in an ESA Parabolic Flight Campaign. In this test campaign the 3D robot has been converted in a 2D robot taking advantage of its modular structure, and it has been suspended by means of air-bearings on a granite plane. In this way it is possible to perform simulated microgravity tests without time constraints. The base of the robot is fixed on ground by means of a custom design dynamometer, which measures the torque transferred to ground to be minimized. The experimental results validated the proposed solutions and confirmed their good performance. © 2010 by Silvio Cocuzza. Cocuzza; Pretto; Debei

Journal: English

Published: doi

DOI: WOS:000279276700001

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Volume: ACTA ASTRONAUTICA###0094-5765 Pages: 295-Reaction torque control of redundant space robotic systems for orbital maintenance and simulated microgravity tests

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Authors: Penasa, M; Cassandro, M; Pretto, D; De Marchi, M; Comin, A; Chessa, S; Dal Zotto, R; Bittante, G; Dept Anim Sci; Dept Anim Sci; Dept Vet Sci & Technol Food Safety; The aim of the study was to quantify the effects of composite β- and κ-casein (CN) genotypes on genetic variation of milk coagulation properties (MCP); milk yield; fat, protein, and CN contents; somatic cell score; pH; and titratable acidity (TA) in 1,042 Italian Holstein-Friesian cows. Milk coagulation properties were defined as rennet coagulation time (RCT) and curd firmness (a30). Variance components were estimated using 2 animal models: model 1 included herd, days in milk, and parity as fixed effects and animal and residual as random effects, and model 2 was model 1 with the addition of composite β- and κ-CN genotype as a fixed effect. Genetic correlations between RCT and a30 and between these traits and milk production traits were obtained with bivariate analyses, based on the same models. The inclusion of casein genotypes led to a decrease of 47, 68, 18, and 23% in the genetic variance for RCT, a30, pH, and TA, respectively, and less than 6% for other traits. Heritability of RCT and a30 decreased from 0.248 to 0.143 and from 0.123 to 0.043, respectively. A moderate reduction was found for pH and TA, whereas negligible changes were detected for other milk traits. Estimates of genetic correlations were comparable between the 2 models. Results show that composite β- and κ-CN genotypes are important for RCT and a30 but cannot replace the recording of MCP themselves. © 2010 American Dairy Science Association. Penasa; Cassandro; Pretto; De Marchi; Comin; Chessa; Dal Zotto; Bittante

Journal: English

Published: doi

DOI: WOS:000279026800052

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Volume: JOURNAL OF DAIRY SCIENCE###0022-0302 Pages: 3349-Short communication: Influence of composite casein genotypes on additive genetic variation of milk production traits and coagulation properties in Holstein-Friesian cows

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Authors: PENSIERI D'ORIENTE::journal64400::600; Non assegn; ITA; D. De Pretto

Published: title_year

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Authors: Pretto, D; De Marchi, M; Dalvit, C; Cassandro, M; Dipartimento Sci Anim; Dipartimento Sci Anim; Aim of this study was to compare profitability of Burlina and Holstein Friesian cows in northern Italy. Cow's profitability was calculated for each breed, with consideration of economic incentive programs and alternative milk pricing scenarios. The difference in annual profitability between Burlina and Holstein Friesian ranged from -€719 to -€274 per cow per year. In a low-input management level with a cow's incentive payment and a specific cheese market strategy the low milk yield of Burlina can be compensate respect to Holstein Friesian. Pretto; de Marchi; Dalvit; Cassandro

Journal: English

Published: doi

DOI: WOS:000279461400005

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Volume: ITALIAN JOURNAL OF ANIMAL SCIENCE###1594-4077 Pages: 67-Comparing profitability of Burlina and Holstein Friesian cattle breeds

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Authors: Penasa, M; Cecchinato, A; Battagin, M; De Marchi, M; Pretto, D; Cassandro, M; Dept Anim Sci; Dept Anim Sci; The aim of the study was to infer (co)variance components for daily milk yield, fat and protein contents, and somatic cell score (SCS) in Burlina cattle (a local breed in northeast Italy). Data consisted of 13 576 monthly test-day records of 666 cows (parities 1 to 8) collected in 10 herds between 1999 and 2009. Repeatability animal models were implemented using Bayesian methods. Flat priors were assumed for systematic effects of herd test date, days in milk, and parity, as well as for permanent environmental, genetic, and residual effects. On average, Burlina cows produced 17.0 kg of milk per day, with 3.66 and 3.33% of fat and protein, respectively, and 358 000 cells per mL of milk. Marginal posterior medians (highest posterior density of 95%) of heritability were 0.18 (0.09-0.28), 0.28 (0.21-0.36), 0.35 (0.25-0.49), and 0.05 (0.01-0.11) for milk yield, fat content, protein content, and SCS, respectively. Marginal posterior medians of genetic correlations between the traits were low and a 95% Bayesian confidence region included zero, with the exception of the genetic correlation between fat and protein contents. Despite the low number of animals in the population, results suggest that genetic variance for production and quality traits exists in Burlina cattle. Penasa; Cecchinato; Battagin; de Marchi; Pretto; Cassandro

Journal: English

Published: Penasa M.; Cecchinato A.; Battagin M.; de Marchi M.; Pretto D.; Cassandro M.

DOI: WOS:000286161600009

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Volume: JOURNAL OF APPLIED GENETICS###1234-1983 Pages: 495-Bayesian inference of genetic parameters for test-day milk yield, milk quality traits, and somatic cell score in Burlina cows

AAB-1934-2021||FQR-6181-2022||FZR-4210-2022

Authors: false; WOS:000291173900009 10.1016/j.actaastro.2010.06.014

Journal: Italy||Italy||Italy

Published: ACTA ASTRONAUTICA

DOI: ACTA ASTRONAUTICA###0094-5765

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Volume: Silvio||Isacco||Stefano Pages: AI-Italy||Italy||Italy

Keywords: 501100003500 - Università degli Studi di Padova;