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.

Työnantajabrandin vision suhde todellisuuteen

Kilpailu osaavasta työvoimasta on saanut yritykset panostamaan työnantajabrandiinsa. Työnantajabrandi yhtenä yrityksen brandipääoman osa-alueena auttaa yrityksiä erottumaan kilpailijoista ja siten houkuttelemaan yritykseen sopivia työntekijöitä sekä säilyttämään jo olemassa olevat työntekijät. Työnantajabrandi ei aina näyttäydy yrityksen työntekijöille tai –hakijoille niin kuin yritys sen haluaisi näyttäytyvän. Henkilöstöhallinnon ja johdon visio saattaa siis olla ristiriidassa sen kanssa, miten brandi todellisuudessa koetaan. Mikäli yritys ei pysty viestittämään oikeanlaista brandi-imagoa tai säilyttämään brandilupauksiaan vaikuttaa tämä yrityksen työntekijöiden sitoutumiseen ja tyytyväisyyteen negatiivisesti. Lisäksi yritykseen hakeutuu töihin yrityksen arvomaailmaan sopimattomia työntekijöitä. Tutkimuksen tarkoituksena on selvittää työnantajabrandin vision suhdetta todellisuuteen case-yrityksen kautta. Case-yritykseksi on valittu kansainvälinen konsultointiyritys, jolle osaava työvoima on elinehto. Tutkimusmenetelmäksi valittiin puolistrukturoidut haastattelut eli aihetta on lähestytty laadullisen menetelmän kautta. Tutkimukseen haastateltiin vision selvittämiseksi case-yrityksen henkilöstöhallintoa sekä perehdyttiin olemassa olevaan materiaaliin yrityksen brandista. Vision toteutumisen selvittämiseksi haastateltiin 19 työntekijää yrityksen kahdesta eri liiketoimintayksiköstä. Teorian pohjalta tarkentunut teoreettinen viitekehys pitää sisällään yrityksen psykologisen sopimuksen, sisäisen ja ulkoisen brandiviestinnän sekä organisaatiokulttuurin. Haastattelut rakennettiin näiden teemojen ympärille. Empiirisen osuuden tulokset vahvistavat teoreettista viitekehystä, jonka mukaan psykologisella sopimuksella, brandiviestinnällä ja organisaatiokulttuurilla on vaikutusta siihen, miten työnantajabrandi koetaan yrityksen työntekijöiden keskuudessa. Organisaatiokulttuurin ja sitä ilmentävän brandipersoonallisuuden osalta korostuu yrityksen työntekijöiden sopivuus ja yhtäläisyys yrityksen organisaatiokulttuuriin voimistamaan haluttua brandimielikuvaa. Psykologisen sopimuksen osalta empiria tukee todenmukaisen kuvan luomisen merkitystä yrityksen brandiviestinnässä. Lisäksi psykologisen sopimuksen osalta sosiaaliset edut nähdään tärkeänä tekijänä työnantajassa. Ihmisistä välittämisellä ja työilmapiirillä voidaan nähdä olevan suuri merkitys työntekijöiden työssä viihtymiselle. Työntekijät myös odottavat nykypäivänä nopeaa urakehitystä ja koulutukseen panostamista uraltaan. Lisäksi joustavuus ja vapaa-ajan ja työn tasapainottaminen koetaan tärkeiksi. Haastattelut tukevat myös teoreettisen viitekehyksen oletusta, että yrityksen visio työnantajabrandista eroaa usein siitä kuvasta, joka työntekijöille välittyy

Design and implementation of machine vision system for the mobile assembly robot

The review of intelligent machines shows that the demand for new ways of helping people in perception of the real world is becoming higher and higher every year. This thesis provides information about design and implementation of machine vision for mobile assembly robot. The work has been done as a part of LUT project in Laboratory of Intelligent Machines. The aim of this work is to create a working vision system. The qualitative and quantitative research were done to complete this task. In the first part, the author presents the theoretical background of such things as digital camera work principles, wireless transmission basics, creation of live stream, methods used for pattern recognition. Formulas, dependencies and previous research related to the topic are shown. In the second part, the equipment used for the project is described. There is information about the brands, models, capabilities and also requirements needed for implementation. Although, the author gives a description of LabVIEW software, its add-ons and OpenCV which are used in the project. Furthermore, one can find results in further section of considered thesis. They mainly represented by screenshots from cameras, working station and photos of the system. The key result of this thesis is vision system created for the needs of mobile assembly robot. Therefore, it is possible to see graphically what was done on examples. Future research in this field includes optimization of the pattern recognition algorithm. This will give less response time for recognizing objects. Presented by author system can be used also for further activities which include artificial intelligence usage.