FABRIC: A Framework for the Design and Evaluation of Collaborative Robots with Extended Human Adaptation

A limitation for collaborative robots (cobots) is their lack of ability to adapt to human partners, who typically exhibit an immense diversity of behaviors. We present an autonomous framework as a cobot's real-time decision-making mechanism to anticipate a variety of human characteristics and behaviors, including human errors, toward a personalized collaboration. Our framework handles such behaviors in two levels: 1) short-term human behaviors are adapted through our novel Anticipatory Partially Observable Markov Decision Process (A-POMDP) models, covering a human's changing intent (motivation), availability, and capability; 2) long-term changing human characteristics are adapted by our novel Adaptive Bayesian Policy Selection (ABPS) mechanism that selects a short-term decision model, e.g., an A-POMDP, according to an estimate of a human's workplace characteristics, such as her expertise and collaboration preferences. To design and evaluate our framework over a diversity of human behaviors, we propose a pipeline where we first train and rigorously test the framework in simulation over novel human models. Then, we deploy and evaluate it on our novel physical experiment setup that induces cognitive load on humans to observe their dynamic behaviors, including their mistakes, and their changing characteristics such as their expertise. We conduct user studies and show that our framework effectively collaborates non-stop for hours and adapts to various changing human behaviors and characteristics in real-time. That increases the efficiency and naturalness of the collaboration with a higher perceived collaboration, positive teammate traits, and human trust. We believe that such an extended human adaptation is key to the long-term use of cobots.Comment: The article is in review for publication in International Journal of Robotics Researc

Modelling of the effect of scale on the compressibility parameters of fine-grained soils

The effect of sample scale represents a challenge when obtaining engineering parameters in the laboratory compared to those obtained in the field. This study aimed at contributing to existing knowledge numerically using the finite element software PLAXIS 2D. The investigations were analysed in terms of height scale (HS) and diameter scale (DS) through a series of laboratory tests. Its effect on compressibility parameters such as coefficient of consolidation (cv) was noted experimentally and showed that the sample scale greatly influences soil parameters most particularly at DS. The soil behaviour was found to be dependent on both DS and HS with a correlation factor of 0.650 and 0.062, respectively. The experimental data were validated in PLAXIS and a new proposed model was developed in PLAXIS 2D under the DS. The new proposed model developed was found to show no significant difference with the laboratory data

Resistance of thermally modified ash (Fraxinus excelsior L.) wood under steam pressure against rot fungi, soil-inhabiting micro-organisms and termites

Thermal modification processes have been developed to increase the biological durability and dimensional stability of wood. The aim of this paper was to study the influence of ThermoWood® treatment intensity on improvement of wood decay resistance against soil-inhabiting micro-organisms, brown/white rots and termite exposures. All of the tests were carried out in the laboratory with two different complementary research materials. The main research material consisted of ash (Fraxinus excelsior L.) wood thermally modified at temperatures of 170, 200, 215 and 228 °C. The reference materials were untreated ash and beech wood for decay resistance tests, untreated ash wood for soil bed tests and untreated ash, beech and pine wood for termite resistance tests. An agar block test was used to determine the resistance to two brown-rot and two white-rot fungi according to CEN/TS 15083-1 directives. Durability against soil-inhabiting micro-organisms was determined following the CEN/TS 15083-2 directives, by measuring the weight loss, modulus of elasticity (MOE) and modulus of rupture (MOR) after incubation periods of 24, 32 and 90 weeks. Finally, Reticulitermes santonensis species was used for determining the termite attack resistance by non-choice screening tests, with a size sample adjustment according to EN 117 standard directives on control samples and on samples which have previously been exposed to soil bed test. Thermal modification increased the biological durability of all samples. However, high thermal modification temperature above 215 °C, represented by a wood mass loss (ML%) due to thermal degradation of 20%, was needed to reach resistance against decay comparable with the durability classes of ‘‘durable’’ or ‘‘very durable’’ in the soil bed test. The brown-rot and white-rot tests gave slightly better durability classes than the soil bed test. Whatever the heat treatment conditions are, thermally modified ash wood was not efficient against termite attack neither before nor after soft rot degradation

Comparison of Artificial Neural Networks models with correlative works on undrained shear strength

WOS: 000272710700009In recent years, the Artificial Neural Network (ANN) modelling that has been used in the solution of the complex problems has gained an increasing interest in soil science. The ANN modelling is also getting more popular in soil mechanics applications. It is a preferable method among the other approaching methods because of having quick results in test phase in short time. This paper describes the ANN models for estimating undrained shear strength (S(u)) of cohesive soils from SPT (Standard Penetration Test) data with index properties in Turkey. The performance of the ANN models is investigated using different input variables such as measured N, corrected N (N(60)) value, natural water content (w(n)), liquid limit (w(L)), plasticity index (I(p)). In this study the ANN models are compared to empirical methods. The results indicate the superior performance of ANN models over the empirical methods

Measurement of side friction between specimen and consolidation ring with newly designed oedometer cell

WOS: 000236637600011Many studies were performed to investigate the effect of the thickness of clay layer on the secondary compression. To find the stress-strain behavior of a tall specimen in the laboratory we have to face the major problem of friction. Without knowing the friction, the data obtained from the high specimen is not easy to interpret. The goal of the present paper is to explain the adoption of a new oedometer cell to measure frictional effects between the consolidation ring and specimen. It is observed that the side friction does not remain constant during the test and slightly increased with time at a decreasing rate. The amount of the side friction depends upon the level of the applied vertical consolidation stress on the specimen. Friction is found to be most significant at low stresses where the clay is still overconsolidated

Relationships between SPT-N value and undrained shear strength of fine-grained soils in Turkey [Türkiye'de SPT-N degeri ile i·nce daneli zeminlerin drenajsiz kayma mukavemeti arasindaki i·lişkiler]

In engineering applications, information obtained during soil explorations may be limited due to the difficulties encountered in sampling, testing and the costs involved. So, it is useful to determine properties of soils by using a small number of soil parameters that can be obtained easily. In this study the correlations between the SPT-N value and undrained shear strength (C 11 ) are examined and developed for types of fine-grained soils based on Standard Penetration Test (SPT) corrections and test type considered statistically, and comparisons are made with previous studies. It is observed that while the correlations proposed by Terzaghi and Peck (1967), commonly used in practice, and Stroud (1974) are compatable with those proposed by the current study, those proposed by the others have given quite high results

Determination of undrained strength of fine-grained soils by means of SPIT and its application in Turkey

WOS: 000239397600004The Standard Penetration Test (SPT) is one of the oldest and the most common in situ test used in soil explorations. In the recent years with the advent of new technology and techniques in determining the drawbacks in SPT, several researchers have attempted to correlate corrected field measured values with several soil properties. In this context, corrections applied to field values have become critical. In this study a questionnaire including the performance of the standard penetration test and equipment used in practice in Turkey is circulated in order to determine the relevant correction factors. Thus the appropriate corrections are used in acquiring corrected SPT-N values. The relationships between SPT-N and the undrained shear strength (S-u) are examined from the statistical point of view by taking the test types and SPT corrections into consideration, and comparison is made with previous studies. It is observed that SPT corrections play an important role on the obtained correlation equations. In addition, the importance of the effects of test types on the correlations is also emphasized. The Standard Penetration Test is found to be sufficient for reliable assessment of S-u. (C) 2006 Elsevier B.V. All rights reserved

Designing singular jet grouting column for sandy soils

In this study, the bearing capacity and settlement values of jet grouting columns with the same diameter in very loose and loose sandy soils were estimated by theoretical approaches and numerical analysis depending on the change in the length of the jet grout columns and soil relative densities, and those values were compared with each other. The changes in bearing capacity and settlement values obtained from soil parameters, jet grouting column length and method differences were examined. In the designing of the jet grouting column, these factors should be determined carefully and correctly. The bearing capacity of the jet grouting column is calculated by the theoretical approach considering as a pile. The settlement values of the jet grouting column were calculated by semi-empirical, empirical and theoretical methods. In numerical analyses, single jet grouting column was modelled with Mohr Coulomb and Hardening Soil models in axial symmetry model and the bearing capacity and settlement values of singular jet grouting column were determined. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature

Comparison of fine-grained soils of the kolsuz and AraplA +/- areas in the Central Anatolia (NiCde, Turkey) in terms of geotechnical properties

WOS: 000319159900014Clayey soils are used in various industrial applications as raw material. However, they are also used both as materials and soils on which constructions are built in the geotechnical engineering. Therefore, estimation of soil behavior in terms of design is vital. In this context, it is necessary to determine the engineering properties of the soils. There are voluminous study on the geology, mineralogy and chemistry of the clayey soils in the Central Anatolia, NiC de (Turkey). However, not many studies deal with their geotechnical properties. In the current study, the engineering properties of clayey soils are determined through laboratory tests on the clayey soil samples taken from the AraplA +/- and Kolsuz areas and also the comparison is made between clayey soils in the AraplA +/- and Kolsuz areas considering their geotechnical properties. As a result, it is observed that the fine-grained soils of the Kolsuz area are inactive and have low plasticity (CL) with average w (L) of 32 and w (P) of 19. The fine-grained soils of the AraplA +/- area have high plasticity (MH) with average w (L) of 96 and w (P) of 57 and are active. It is also found that while the fine grained soils of the Kolsuz area has almost no swelling potential, those of the AraplA +/- area has high swelling potential based on their mineralogical contents, consistency limits, activities and swelling pressures

Pelletization of magnetite ore with colemanite added organic binders

A new generation binder consisting of an organic binder and a borate salt was tested as an alternative to bentonite in magnetite ore pelletization. Carboxyl methyl cellulose (CMC),Ciba DPEP06-0007 and corn starch, and calcined colemanite were used as organic binders and the borate salt, respectively. They were added to the pellet feed separately and in different combinations at several addition levels. It was found that the use of organic binders is sufficient in terms of wet pellet quality; however, they fail to render the required compressive strength to pre-heated and fired pellets. Therefore, organic binders and calcined colemanite were used together so that wet pellets, pre-heated and fired pellets would be of the required quality. The results showed that the use of an organic binder together with calcined colemanite indeed yielded pellets with equal or better wet and indurated pellet qualities compared to the pellets produced with bentonite binder alone