Learning Grasp Affordances from Vision

Monimutkaisissa ja muuttuvissa ympäristöissä työskentelevät robotit tarvitsevat kykyä manipuloida ja tarttua esineisiin. Tämä työ tutkii robottitarttumisen ja robottitartuntapis-teiden koneoppimisen aiempaa tutkimusta ja nykytilaa. Nykyaikaiset menetelmät käydään läpi, ja Le:n koneoppimiseen pohjautuva luokitin toteutetaan, koska se tarjoaa parhaan onnistumisprosentin tutkituista menetelmistä ja on muokattavissa sopivaksi käytettävissä olevalle robotille. Toteutettu menetelmä käyttää intensititeettikuvaan ja syvyyskuvaan po-hjautuvia ominaisuuksi luokitellakseen potentiaaliset tartuntapisteet. Tämän toteutuksen tulokset esitellään.

Neural mechanisms underlying conscious and unconscious vision. Evidence from event-related potentials and transcranial magnetic stimulation

Vision affords us with the ability to consciously see, and use this information in our behavior. While research has produced a detailed account of the function of the visual system, the neural processes that underlie conscious vision are still debated. One of the aims of the present thesis was to examine the time-course of the neuroelectrical processes that correlate with conscious vision. The second aim was to study the neural basis of unconscious vision, that is, situations where a stimulus that is not consciously perceived nevertheless influences behavior. According to current prevalent models of conscious vision, the activation of visual cortical areas is not, as such, sufficient for consciousness to emerge, although it might be sufficient for unconscious vision. Conscious vision is assumed to require reciprocal communication between cortical areas, but views differ substantially on the extent of this recurrent communication. Visual consciousness has been proposed to emerge from recurrent neural interactions within the visual system, while other models claim that more widespread cortical activation is needed for consciousness. Studies I-III compared models of conscious vision by studying event-related potentials (ERP). ERPs represent the brain’s average electrical response to stimulation. The results support the model that associates conscious vision with activity localized in the ventral visual cortex. The timing of this activity corresponds to an intermediate stage in visual processing. Earlier stages of visual processing may influence what becomes conscious, although these processes do not directly enable visual consciousness. Late processing stages, when more widespread cortical areas are activated, reflect the access to and manipulation of contents of consciousness. Studies IV and V concentrated on unconscious vision. By using transcranial magnetic stimulation (TMS) we show that when early visual cortical processing is disturbed so that subjects fail to consciously perceive visual stimuli, they may nevertheless guess (above chance-level) the location where the visual stimuli were presented. However, the results also suggest that in a similar situation, early visual cortex is necessary for both conscious and unconscious perception of chromatic information (i.e. color). Chromatic information that remains unconscious may influence behavioral responses when activity in visual cortex is not disturbed by TMS. Our results support the view that early stimulus-driven (feedforward) activation may be sufficient for unconscious processing. In conclusion, the results of this thesis support the view that conscious vision is enabled by a series of processing stages. The processes that most closely correlate with conscious vision take place in the ventral visual cortex ~200 ms after stimulus presentation, although preceding time-periods and contributions from other cortical areas such as the parietal cortex are also indispensable. Unconscious vision relies on intact early visual activation, although the location of visual stimulus may be unconsciously resolved even when activity in the early visual cortex is interfered with.

From Persephone to Pan: D. H. Lawrence's mythopoeic vision of the integrated personality with special emphasis on the short fiction and other writings in the early nineteen twenties

This doctoral thesis was published in printed form in 1987. It was digitized from paper copy in 2013. Unfortunately on some pages the digitizaion process has not been complete, i.e there are some minor typographic erros on some pages.

Experimental validation of a 3-D vision-based measurement system applied to robot calibration

One of the problems that slows the development of off-line programming is the low static and dynamic positioning accuracy of robots. Robot calibration improves the positioning accuracy and can also be used as a diagnostic tool in robot production and maintenance. A large number of robot measurement systems are now available commercially. Yet, there is a dearth of systems that are portable, accurate and low cost. In this work a measurement system that can fill this gap in local calibration is presented. The measurement system consists of a single CCD camera mounted on the robot tool flange with a wide angle lens, and uses space resection models to measure the end-effector pose relative to a world coordinate system, considering radial distortions. Scale factors and image center are obtained with innovative techniques, making use of a multiview approach. The target plate consists of a grid of white dots impressed on a black photographic paper, and mounted on the sides of a 90-degree angle plate. Results show that the achieved average accuracy varies from 0.2mm to 0.4mm, at distances from the target from 600mm to 1000mm respectively, with different camera orientations.

Performance evaluation of 3D computer vision techniques

This work presents the implementation and comparison of three different techniques of three-dimensional computer vision as follows: • Stereo vision - correlation between two 2D images • Sensorial fusion - use of different sensors: camera 2D + ultrasound sensor (1D); • Structured light The computer vision techniques herein presented took into consideration the following characteristics: • Computational effort ( elapsed time for obtain the 3D information); • Influence of environmental conditions (noise due to a non uniform lighting, overlighting and shades); • The cost of the infrastructure for each technique; • Analysis of uncertainties, precision and accuracy. The option of using the Matlab software, version 5.1, for algorithm implementation of the three techniques was due to the simplicity of their commands, programming and debugging. Besides, this software is well known and used by the academic community, allowing the results of this work to be obtained and verified. Examples of three-dimensional vision applied to robotic assembling tasks ("pick-and-place") are presented.

Machine vision methods for process measurements in pulping

The papermaking industry has been continuously developing intelligent solutions to characterize the raw materials it uses, to control the manufacturing process in a robust way, and to guarantee the desired quality of the end product. Based on the much improved imaging techniques and image-based analysis methods, it has become possible to look inside the manufacturing pipeline and propose more effective alternatives to human expertise. This study is focused on the development of image analyses methods for the pulping process of papermaking. Pulping starts with wood disintegration and forming the fiber suspension that is subsequently bleached, mixed with additives and chemicals, and finally dried and shipped to the papermaking mills. At each stage of the process it is important to analyze the properties of the raw material to guarantee the product quality. In order to evaluate properties of fibers, the main component of the pulp suspension, a framework for fiber characterization based on microscopic images is proposed in this thesis as the first contribution. The framework allows computation of fiber length and curl index correlating well with the ground truth values. The bubble detection method, the second contribution, was developed in order to estimate the gas volume at the delignification stage of the pulping process based on high-resolution in-line imaging. The gas volume was estimated accurately and the solution enabled just-in-time process termination whereas the accurate estimation of bubble size categories still remained challenging. As the third contribution of the study, optical flow computation was studied and the methods were successfully applied to pulp flow velocity estimation based on double-exposed images. Finally, a framework for classifying dirt particles in dried pulp sheets, including the semisynthetic ground truth generation, feature selection, and performance comparison of the state-of-the-art classification techniques, was proposed as the fourth contribution. The framework was successfully tested on the semisynthetic and real-world pulp sheet images. These four contributions assist in developing an integrated factory-level vision-based process control.

Weed mapping using a machine vision system

Weed mapping is a useful tool for site-specific herbicide applications. The objectives of this study were (1) to determine the percentage of land area covered by weeds in no-till and conventionally tilled fields of common bean using digital image processing and geostatistics, and (2) to compare two types of cameras. Two digital cameras (color and infrared) and a differential GPS were affixed to a center pivot structure for image acquisition. Sample field images were acquired in a regular grid pattern, and the images were processed to estimate the percentage of weed cover. After calculating the georeferenced weed percentage values, maps were constructed using geostatistical techniques. Based on the results, color images are recommended for mapping the percentage of weed cover in no-till systems, while infrared images are recommended for weed mapping in conventional tillage systems.

Comparison between dSPACE and NI systems based on real-time intelligent control of a teleoperated hydraulic servo system

The Laboratory of Intelligent Machine researches and develops energy-efficient power transmissions and automation for mobile construction machines and industrial processes. The laboratory's particular areas of expertise include mechatronic machine design using virtual technologies and simulators and demanding industrial robotics. The laboratory has collaborated extensively with industrial actors and it has participated in significant international research projects, particularly in the field of robotics. For years, dSPACE tools were the lonely hardware which was used in the lab to develop different control algorithms in real-time. dSPACE's hardware systems are in widespread use in the automotive industry and are also employed in drives, aerospace, and industrial automation. But new competitors are developing new sophisticated systems and their features convinced the laboratory to test new products. One of these competitors is National Instrument (NI). In order to get to know the specifications and capabilities of NI tools, an agreement was made to test a NI evolutionary system. This system is used to control a 1-D hydraulic slider. The objective of this research project is to develop a control scheme for the teleoperation of a hydraulically driven manipulator, and to implement a control algorithm between human and machine interaction, and machine and task environment interaction both on NI and dSPACE systems simultaneously and to compare the results.

Vision, image, record : a cultivation of the visual field

I den första delen av den här avhandlingen presenteras en bildens genealogi. Den skildrar hur begreppen för bilden, seendet och jaget utvecklades i relation till varandra i en specifik vetenskaplig och filosofisk kontext. Berättelsen sträcker sig från den tidiga renässansen och det perspektivistiska måleriet, till fotografiets födelse och positivismen. Den här utvecklingen medförde en form av reduktionism i vilken jagets roll – betydelsen av den mänskliga psykologin, vårt omdöme, vår uppmärksamhet och vår vilja – blev förbisedd. Inom den här tanketraditionen uppstod en förskjutning, från en förståelse av bilden som en representation av det tredimensionella rummet på en tvådimensionell yta, till en uppfattning om bilden som en genomskinlig ruta, ett fönster ut mot världen. Idén om avbildningen som en neutral ”blick från ingenstans” kom att förstärka en skeptisk hållning till kommunikation, dialog och vittnesmål och därmed även undergräva vår tillit till varandra och följaktligen vår tillit till oss själva. I den andra delen erbjuder författaren ett alternativ till den tanketradition som behandlas i den första delen. Det som blev förbisett i uppfattningen om en blick från ingenstans var att bilden är ett hjälpmedel då vi bearbetar vårt synfält. Bilden hjälper oss att dela vår syn på saker. Genom den här uppgiften av att dela blir bilden riktningsgivande i våra försök att orientera oss i världen. Jag kan stå bredvid en annan människa och se vad hon ser, men jag vet inte nödvändigtvis hur hon uppfattar det vi ser. Bilden lägger till ett led i det här förhållandet eftersom den inte enbart visar vad den andra ser. När bilden fungerar som den skall visar den också hur den andra ser och på det här sättet blir bilden verksam. Den föreliggande avhandlingen kombinerar epistemologi med vetenskapshistoria och visuella kulturstudier, men dess huvudintresse är filosofiskt. Den befattar sig med filosofiska missförstånd angående avbildning som en mimetisk konstform, kunskap som domesticering och varseblivning som mottagning av data. ------------------------------------------------------ Tämän väitöskirjan ensimmäinen osa selvittää kuvakäsitteen genealogiaa. Se havainnollistaa miten kuvan, näkemisen ja minän käsitteet kehittyivät suhteessa toisiinsa. Kertomus ulottuu varhaisesta renessanssista ja perspektivistisestä maalaustaiteesta, positivismin aikakauteen ja valokuvan syntyyn. Tämä kehitys toi mukanaan reduktionismin jossa minän rooli – ihmisen psykologian merkitys, meidän arviointikyky, meidän huomiokyky sekä meidän tahtomme – vaipui unohduksiin. Ajatusmaailmassa tapahtui siirtymä, kuvan merkitys vaihtui käsityksestä jossa se on kolmiulotteisen tilan representaatio kaksiulotteisella pinnalla, käsitykseen jossa kuva on läpinäkyvä ruutu, ikkuna kohti maailmaa. Ajatus kuvasta neutraalin näkökulman kantajana vahvisti skeptistä suhtautumista kommunikaatiota, dialogisuutta ja subjektiivisuutta kohtaan. Tämä skeptisyys ilmentyi myös vahvana epäluottamuksena ihmiskeskeisyyttä ja toiseutta kohtaan. Toisessa osassa tekijä tarjoaa vaihtoehdon tälle skeptiselle ajatusmaailmalle jota tarkastellaan ensimmäisessä osassa. Kuva on myös väline joka auttaa meitä jäsentämään meidän näkökenttäämme. Se auttaa meitä jakamaan meidän käsityksiä toistemme kanssa. Tämä näkemisen jakamisen käytäntö on kuvan keskeinen tehtävä. Voin seistä toisen ihmisen vieressä ja nähdä samat asiat kuin hän, mutta en välttämättä ymmärrä miten hän näkee nämä asiat. Kuva lisää jotain olennaista tähän suhteeseen. Kun kuva toimii niin kun sen kuuluu toimia, se näyttää myös miten toinen näkee, tällä tavalla kuvasta tulee välittäjä. Tämä väitöskirja yhdistää epistemologiaa, tieteen historiaa ja visuaalisen kulttuurin tutkimusta, mutta sen pääasiallinen tavoite on filosofinen. Se käsittelee filosofisia väärinkäsityksiä koskien kuvan eideettisyyttä.

Long-term loss of color vision after exposure to mercury vapor

We evaluated the color vision of 24 subjects (41.6 ± 6.5 years; 6 females) who worked in fluorescent lamp industries. They had been occupationally exposed to mercury vapor (10.6 ± 5.2 years) and had been away from the source of exposure for 6.4 ± 4.04 years. Mean urinary concentration of mercury was 40.6 ± 36.4 µg/g creatinine during or up to 1 year after exposure and 2.71 ± 1.19 µg/g creatinine at the time of color vision testing or up to 1 year thereafter. All patients were diagnosed with chronic mercury intoxication, characterized by clinical symptoms and neuropsychological alterations. A control group (N = 36, 48.6 ± 11.9 years, 10 females, 1.5 ± 0.47 µg mercury/g creatinine) was subjected to the same tests. Inclusion criteria for both groups were Snellen VA 20/30 or better and absence of known ophthalmologic pathologies. Color discrimination was assessed with the Farnsworth D-15 test (D-15) and with the Lanthony D-15d test (D-15d). Significant differences were found between the two eyes of the patients (P < 0.001) in both tests. Results for the worst eye were also different from controls for both tests: P = 0.014 for D-15 and P < 0.001 for D-15d. As shown in previous studies, the D-15d proved to be more sensitive than the D-15 for the screening and diagnosis of the color discrimination losses. Since color discrimination losses were still present many years after the end of exposure, they may be considered to be irreversible, at least under the conditions of the present study.

Novel control, haptic and calibration methods for teleoperated electrohydraulic servo systems

The aim of this thesis is to propose a novel control method for teleoperated electrohydraulic servo systems that implements a reliable haptic sense between the human and manipulator interaction, and an ideal position control between the manipulator and the task environment interaction. The proposed method has the characteristics of a universal technique independent of the actual control algorithm and it can be applied with other suitable control methods as a real-time control strategy. The motivation to develop this control method is the necessity for a reliable real-time controller for teleoperated electrohydraulic servo systems that provides highly accurate position control based on joystick inputs with haptic capabilities. The contribution of the research is that the proposed control method combines a directed random search method and a real-time simulation to develop an intelligent controller in which each generation of parameters is tested on-line by the real-time simulator before being applied to the real process. The controller was evaluated on a hydraulic position servo system. The simulator of the hydraulic system was built based on Markov chain Monte Carlo (MCMC) method. A Particle Swarm Optimization algorithm combined with the foraging behavior of E. coli bacteria was utilized as the directed random search engine. The control strategy allows the operator to be plugged into the work environment dynamically and kinetically. This helps to ensure the system has haptic sense with high stability, without abstracting away the dynamics of the hydraulic system. The new control algorithm provides asymptotically exact tracking of both, the position and the contact force. In addition, this research proposes a novel method for re-calibration of multi-axis force/torque sensors. The method makes several improvements to traditional methods. It can be used without dismantling the sensor from its application and it requires smaller number of standard loads for calibration. It is also more cost efficient and faster in comparison to traditional calibration methods. The proposed method was developed in response to re-calibration issues with the force sensors utilized in teleoperated systems. The new approach aimed to avoid dismantling of the sensors from their applications for applying calibration. A major complication with many manipulators is the difficulty accessing them when they operate inside a non-accessible environment; especially if those environments are harsh; such as in radioactive areas. The proposed technique is based on design of experiment methodology. It has been successfully applied to different force/torque sensors and this research presents experimental validation of use of the calibration method with one of the force sensors which method has been applied to.

Quality assurance of refuse derived fuel with machine vision

This thesis studies the use of machine vision in RDF quality assurance and manufacturing. Currently machine vision is used in recycling and material detection and some commer- cial products are available in the market. In this thesis an on-line machine vision system is proposed for characterizing particle size. The proposed machine vision system is based on the mapping between image segmenta- tion and the ground truth of the particle size. The results shows that the implementation of such machine vision system is feasible.

The Formation Of Internationalization Strategies Within The Construction Industry:Vision and Strategy

Internationalization represents a complex topic that has been researched for quite some time. However, since it continues to be extremely current a topic, its significance has not diminished, but maybe even increased in importance. Companies today face extreme pressure to enter new markets in the hope of growing, becoming more profitable, increasing market share, attracting new customers and meeting the requirements of its share- and stakeholders. In the increasingly global business environment of today, companies are facing both challenges and possible advantages of internationalization. Few companies are not operating internationally and it is becoming the question of ‘Why not?’ rather than ‘Why?’ to internationalize business operations. Internationalization and the importance of strategy are discussed in this research from the viewpoint of three case companies that were interviewed about internationalization strategies. This research project is a qualitative study that answers the research question of How is a business strategy constructed for entering a new market? The sub-questions are • How are goals set and what indicators are used to monitor the achievement of these goals? • What are the key characteristics of a strategy implementation process? The research method chosen for this study is a multiple-case study. Three case companies were chosen for the interviews in order to gain in-depth data of internationalization strategies within the construction industry.