A Fast Score-Based Method for Robotic Task-Free Point-to-Point Path Learning

The manipulation of deformable objects represents an open research topic because of the difficulties in accurately modeling the object behavior in real-world scenarios. This paper presents a trajectory planning framework for the assembly of wiring harnesses for the automotive and aerospace sector, reducing the learning time and simultaneously presenting suitable performance and reliability. A genetic algorithm is used to generate new trajectories according to application constraints. Those trajectories are then executed by the robot and evaluated by means of proper sensor feedback. The proposed framework enable to learn and autonomously improve the task execution, while mantaining a significantly low programming time. Experimental results are reported showing how the robot is capable of optimizing the manipulation of the DLOs gaining experience along the task repetition, while showing high success rate from the very beginning of the learning phase

Deformable Linear Objects 3D Shape Estimation and Tracking From Multiple 2D Views

This letter presents DLO3DS , an approach for the 3D shapes estimation and tracking of Deformable Linear Objects (DLOs) such as cables, wires or plastic hoses, using a cheap and compact 2D vision sensor mounted on the robot end-effector. DLO3DS can be applied in all those scenarios in which the perception and manipulation of DLO-like structures are needed, such as in the case of switchgear cabling, wiring harness manufacturing and assembly in the automotive and aerospace industries, or production of hoses for medical applications. The developed procedure is based on a pipeline that first processes the images coming from the 2D camera extracting key topological points along the DLOs. These points are then used to model each DLO with a B-spline curve. Finally, the set of splines obtained from all the images is matched by exploiting a multi-view stereo-based algorithm. DLO3DS is validated both on a real scenario and on simulated data obtained by exploiting a rendering engine for photo-realistic images. In this way, reliable ground-truth data are retrieved and utilized for assessing the estimation error achievable by DLO3DS , which on the employed test set is characterized by a mean reconstruction error of 0.82 mm

Cable Detection and Manipulation for DLO-in-Hole Assembly Tasks

This paper describes a cyber-physical system for the manipulation of Deformable Linear Objects (DLOs) addressing the DLO-in-hole insertion problem targeting an industrial sce-nario, the switchgear's components cabling task. In particular, the task considered is the insertion of DLOs in the switchgear components' holes. This task is very challenging since a precise knowledge of the DLO tip position and orientation is required for a successful operation. We tackled the DLO-in-hole problem from the computer vision perspective constraining our setup on employing just simple 2D images and by using the mobility of the robotic arm for achieving the full 3D knowledge of the DLOs. Then, the DLO tip is detected from two different image planes and the robot's trajectory corrected accordingly before insertion. To prove the effectiveness of the proposed solution, an example scenario is prepared and the method validated experimentally attempting the insertion of several DLOs in a sample switchgear component, obtaining an overall insertion success rate of 82.5 %

Growth and slaughter performance, nitrogen balance and ammonia emission from slurry in pigs fed high fibre diets

The aim of the work was to determine digestibility, nitrogen balance and ammonia emission from excreta, in the typical Italian heavy pig during the last phase of growth, when fed diets with a high fibre content. In comparison with a traditional control diet (C), two diets with 12 and 24% wheat bran (WB12 and WB24) and two other diets with 12 and 24% dried beet pulp (BP12 and BP24) were tested. Totally 76 Landrace x Large White fattening barrows, from 45 to 170 kg live weight distributed in 16 pens, were utilized in the trial. Thirty pigs were allocated to 6 metabolic cages in 5 consecutive periods in order to have 6 observations per treatment. For diets C, WB12 and WB24 daily weight gain (DWG), feed conversion ratio (FCR) and slaughtering performances were also registered, on 20 pigs per dietary treatment. Growing and slaughter performances were similar for pigs fed C and WB12 diets, whilst diet WB24 determined a significant (P<0.05) decrease in performances (growth and feed conversion) in the first period of fattening and a lower dressing percentage at slaughter (85.5, 84.4 and 82.5% for C, WB12 and WB24, respectively). Comparing the diets with the same level of inclusion of the fibrous feeds, WB diets had a lower OM and energy digestibility, while BP diets registered a lower protein but a higher fibre digestibility. Consistently with other experiments, BP diets determined an increase of faecal and a reduction of urinary N, as a percentage of the intake N, as well as a decrease of ammonia emission from the slurries (- 16.6 and -25.3% for BP12 and BP24, in comparison with C diet). For the WB diets the reduction of urinary N and the increase in faecal N were less marked and a reduction of ammonia emissions was not registered

Influence of high levels of beet pulp in the diet on endocrine/metabolic traits, slaughter dressing percentage, and ham quality in Italian heavy pigs

Seventy two Landrace x Large White barrows were divided into three groups and fed different diets: a control traditional diet based on cereals (C) and two with 15 or 30% dried sugar beet pulp (BP15 and BP30, respectively). Animals weighed 106 kg at start and 167 kg at the end of the experiment. Feeding was restricted (2.5 kg DM/head, on average). The aim of the present experiment was to investigate the influence of high levels of beet pulp in the diet of fattening heavy pigs on some endocrine/metabolic traits, on the slaughter dressing percentage and on some parameters related to meat quality, composition and on the ham quality, after 14 months of seasoning. During the experimental period, jugular vein blood samples were collected from C and BP30-fed pigs and plasma was analysed for several metabolic traits. BP30 diet initially increased the plasma glucose level and decreased free amino acids (P<0.05), but this difference disappeared at the end of the experimental period, when insulin level was decreased (P=0.06) by beet pulp administration. During the entire period, 30% beet pulp diet increased total protein and albumin levels (P<0.001) and decreased urea (P<0.05) without affecting plasma leptin. At slaughter, pigs fed BP30 diet were lighter (P<0.001) and with a lower dressing percentage (P<0.001) in comparison with the other two treatments. Pigs fed BP30 diet also had lower ham and loin weights (P<0.05) (but similar ham and loin percentages) and higher liver weight (P<0.05), liver/carcass ratio (P<0.001), gastrointestinal- tract weight (P<0.001) and gastrointestinal-tract/carcass ratio (P<0.001). Pigs fed C diet had a higher dressing percentage in comparison with pigs fed BP15 diet (P<0.01), but no other significant difference was found between pigs fed diets C and BP15. At slaughter, liver samples were taken from C and BP30-fed pigs in order to evaluate the effect of the diet on liver composition. BP30 diet increased dry liver weight (P<0.05) and liver fat content (P<0.01). The iodine value and the fatty acid composition of the backfat revealed no significant difference between pigs fed the control diet and those fed the high fibre diets. Finally, considering the economic importance of ham production, the characteristics of the seasoned hams were evaluated. No difference was observed on ham quality. In conclusion, feeding a diet with a high percentage of dried sugar beet pulp alters protein and energy metabolism and slaughter parameters, without affecting the quality of the seasoned ham

Nitrogen and energy partitioning in two genetic groups of pigs fed low-protein diets at 130 kg body weight

The aim was to evaluate the effect of low-protein (LP) or low-amino acid diets on digestibility, energy and nitrogen (N) utilisation in 2 genetic groups (GG) of pigs (129±11 kg BW). Duroc×Large White (A) pigs were chosen to represent a traditional GG for ham production, and Danbred Duroc (D) pigs to represent a GG with fast growing rate and high carcass lean yield. Dietary treatments: a conventional diet (CONV) containing 13.2% CP, and two LP diets, one with LP (10.4%) and low essential AA (LP1), the second with LP (9.7%) and high essential AA (LP2). Compared to CONV, LP2 had the same essential AA content per unit feed, while LP1 the same essential AA content per unit CP. Feed was restricted (DMI=6.8% BW0.75). Four consecutive digestibility/balances periods were conducted with 24 barrows, 12 A and 12 D. Metabolic cages and respiration chambers were used. No significant difference between diets was registered for digestibility. Nitrogen excreted: 41.3, 33.4 and 29.0 g/d (P=0.009), for CONV, LP1 and LP2 diets, respectively. Nitrogen retention was similar between the diets. Heat production (HP) was the lowest for LP diets. There was a tendency (P=0.079) for a lower energy digestibility in D group. The D pigs also had a higher HP and hence a lower retained energy in comparison with the A pigs. In conclusion: it is possible to reduce N excretion using very LP diets and LP-low AA diets; Danbred GG have a higher heat production and a lower energy retention than A pigs

repeatability and reproducibility of the cornell net carbohydrate and protein system analytical determinations

The increasing use in Italy of the Cornell Net Carbohydrate and Protein System (CNCPS) led researchers of five Italianuniversities to carry out a collaborative study to evaluate the precision of the CNCPS chemical analysis and derivate fractions.Each laboratory conducted in duplicate the chemical analyses according to the Weende (dry matter; crude protein;ether extract; crude fibre; ash), Van Soest (neutral and acid detergent fibre, NDF and ADF; acid detergent lignin; ADL)and CNCPS (soluble proteins, SP; non-protein nitrogen, NPN; neutral and acid detergent insoluble protein, NDIP andADIP; starch, ST) schemes on the same five feeds (barley meal, wheat straw, maize silage, dried lucerne and fieldbeans). Anomalous analytical data were identified and corrected by the “box-plot” graphic tool before the calculation ofthe CNCPS protein (B1, B2 and B3) and carbohydrate (A, B2 and C) fractions. Finally, repeatability (chemical analysis) andreproducibility (chemical analysis and fractions) were calculated and expressed as relative values (repeatability andreproducibility standard deviation as percentage of the corresponding mean, RSDr and RSDR, respectively). Chemicalanalyses of the Weende scheme, together with NDF, ADF and ST analyses, have satisfactory repeatability (0.3-6.2%) andreproducibility (0.3-11.2%) values. On the contrary the ADL, NPN, NDIP and ADIP analyses showed high variability, bothwithin and between laboratories (RSDr and RSDR between 20 and 45%). The SP analysis had an intermediate value ofprecision (RSDr=10.6%; RSDR=16.4%).Finally, since different combinations of several chemical analyses with scarce (ADL, NPN, NDIP, ADIP, SP) or average precision(e.g. NDF and starch) are used to calculate CNCPS fractions (excluding B2 protein fraction), also the reproducibilitiesof these fractions are poor and range from 10 to 20%

Prediction of the nutritive value of maize silage using in vitro and near infrared reflectance spectroscopy (NIRS) techniques

Maize silage is by far the most used forage in the diets for dairy cows and beef cattle in a large part of the Po plain, Italy. However, its chemical composition and its nutritive value range widely according to the genotype and to the climatic and agronomic conditions, particularly with regards to the plant maturity at harvest

Effects of benzoic acid on nitrogen, phosphorus and energy balance and on ammonia emission from slurries in the heavy pig

The effects of two dietary levels of benzoic acid on nitrogen, phosphorus and energy balance were evaluated in the typical Italian heavy pig during the last phase of growth. Six Landrace x Large White barrows of 125 kg body weight (BW) on average were used in a repeated 3x3 Latin Square design and housed in metabolic cages to collect faeces and urine separately, in 3 collection periods of 7 days, after 14 days of adaptation. The animals were individually housed in open circuit respiration chambers to determine the energy metabolism. The dietary treatments were as follows [% on dry matter (DM)]: i) diet C (control): 14.2 crude protein (CP), 3.7 EE, 13.8 NDF; ii) diet B05: diet C plus 0.5% benzoic acid; iii) diet B10: diet C plus 1.0% benzoic acid. DM fed was fixed at 6.8% BW0.75. Apparent digestibility was similar among treatments for all the parameters studied. Nitrogen (N) retention was 35.8, 37.4, 41.6% of intake N for C, B05 and B10, respectively, with no significant difference. Energy and phosphorus balances were not influenced by dietary treatments. Ammonia nitrogen emission from the slurry, expressed as a proportion of the initial slurry nitrogen, was decreased (P=0.049) by the inclusion of benzoic acid in the diet: 35.2, 28.1, 26.2% for C, B05, B10, respectively. The addition of benzoic acid to the diet determined a numerically decrease of the urinary pH. In conclusion, the inclusion of benzoic acid in the diet of the heavy pig is beneficial to the environment without effects on N, phosphorus (P) and energy balances