Robottihitsauksen toimintojen kehittäminen hitsaustuotannossa

Tämän diplomityön tarkoituksena oli kehittää robottihitsauksen toimintoja KKR Steel Oy:ssä. Tärkeimmät tutkimuskohteet olivat robottisolujen toiminnan tehostaminen ja uusien robottihitsaukseen sopivien tuotteiden kartoittaminen. Työ on jaettu teoreettiseen ja käytännön osuuteen. Teoriaosassa perehdytään kirjallisuuskatsauksen kautta robottihitsauksen perusteisiin, hitsauksen robotisointiin sekä tuottavuuteen ja laatuun. Robottihitsauksen osuudessa käsitellään hitsausrobotin rakennetta, siihen liittyviä oheislaitteita ja robottien ohjelmointia. Hitsauksen robotisoinnissa selvitetään syitä robottihitsauksen käyttöönotolle, robotisoitavilta tuotteilta vaadittavia ominaisuuksia sekä erilaisia toimenpiteitä robottiaseman toiminnan tehostamiseksi. Tuottavuuteen liittyvässä osuudessa selvitetään erilaisten laskentakaavojen ja tunnuslukujen käyttöä ja merkitystä hitsauksessa. Käytännön osuudessa kartoitettiin yrityksen robottihitsauksen lähtötilanne ja selvitettiin ongelmakohtien perusteella kehittämistoimenpiteitä. Tutkimuksissa seurattiin ja havainnoitiin hitsaustuotannon eri vaiheita, minkä perusteella laadittiin erilaisia parannuskeinoja. Toimenpiteistä saatavan hyödyn arviointiin käytettiin yrityksen tuotantoon sopivia mittareita kuten läpimenoaikaa ja kaariaikasuhdetta. Havaittujen ongelmakohtien perusteella ryhdyttiin kehittämään hitsauskiinnittimien suunnittelua ja käsittelylaitteiden käyttöä hitsaustuotannossa sekä hyödyntämään etäohjelmointia tuotteiden viennissä robottiasemille. Lisäksi robottiasemien käyttöastetta pyrittiin nostamaan tutkimalla käsinhitsattavia tuotteita ja siirtämällä niistä robotille soveltuvimmat robottiasemille hitsattavaksi.

Modulaarinen arkkitehtuuri tuoteperheen kehittämisessä

Modulaarisen tuotteen kehittäminen tehostaa yrityksen kilpailukykyä ja helpottaa asiakkaiden tarpeiden tyydyttämistä. Tuoteperheen edut verrattaessa massatuotantoon ovat laajempi tuotevalikoima sekä parempi tuotettavuus massaräätälöintiin verrattuna. Eri tuotevaihtoehtoja ja moduuleja on mahdollista kehittää rinnakkain. Moduloitava tuoteperhe helpottaa yrityksen eri vaiheita aina tuotteen suunnittelusta huoltotoimenpiteisiin ja lopulta tuotteen purkamiseen. Asiakkaille tärkeitä hyötyjä moduloinnin osalta ovat tuotteiden parempi laatu ja huollettavuus. Täysin uuden modulaarisen tuoteperheen kehittäminen vaatii runsaasti resursseja suunnitteluosastolla. Modulaarisessa tuotteessa suunnittelutyö voidaan kohdistaa vain tietyn moduulin kohdalle ja suunnitteluaikoja saadaan täten lyhennettyä. Tässä kandidaatintyössä tutkittiin, miten hitsausautomaatiosovelluksissa modulaarisuus on toteutettu sekä pohditaan kehityskohteita, koska hitsausautomaatiosovelluksia tuotetaan runsaasti asiakasräätälöintinä. Tarkasteltavana tuoteperheenä oli robottihitsausportaalit ja hitsaustornit.

Robotiikkatuoteperheen kehittäminen

Robottiikkatuoteperheeseen kuuluu robottihitsausportaalit, joiden päärunko rakentuu kote-lopalkeista. Koteloprofiilien käyttö on suosittua teollisuuden eri aloilla ja se soveltuu hyvin raskaaseen konepajateollisuuteen. Hitsausrobottiportaalin suunnitteluun liittyy monia eri vaiheita ja valituilla teknisillä ratkaisuilla voidaan vaikuttaa valmistettavan tuotteen hitsin laatuun ja työn onnistumiseen. Hitsausrobottiportaalit ovat usein asiakasräätälöityjä ratkaisuja, jolloin suunnittelutyö sekä valmistusvaihe vaativat runsaasti kapasiteettia. Modulaarisuuden avulla suunnittelu- ja valmistusvaiheita on mahdollista nopeuttaa sekä parantaa tuotteen testausta, huollettavuutta ja laatua. Tässä diplomityössä tutkittiin, miten hitsausrobottiportaalin vaakapuomi käyttäytyy ja taipuu erilaisissa kuormitustilanteissa. Lisäksi työssä määritettiin alkuperäisen koteloprofiilin tilalle uusi optimoitu koteloprofiili sekä tarkasteltiin moduloinnin mahdollistamista robo-tiikkatuoteperheen portaalisovelluksiin.

Soldagem GMAW-P robotizada de alumínio: influência do tipo de chanfro, tecimento e sentido de laminação na distorção

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Preenchimento de cavidades provenientes de remoção de trinca em turbinas hidráulicas por meio do processo GMAW-P

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Mecânica, 2016.

Development of a robotic system for switchgear cabling

Industrial robots are an inalienable part of modern automated production. Typical applications of robots include welding, painting, (dis)assembly, packaging, labeling, palletizing, pick and place and others. Many of that applications includes object manipulation. If the shape and position of the object are known in advance, it is possible to design the trajectory of the robot’s end-effector to take and place. Such a strategy is applicable for rigid objects and widely used in the manufacturing field. But flexible (deformable) objects can change their shape and position upon contact with the robot’s end-effector or environment. That is the reason why the general approach is unacceptable. It means that the robot can fail to grasp such an object and can’t place it in the desired position. This thesis has addressed the problem of cable manipulation by bilateral robotic setup for the industrial manufacturing of electrical switchgear. The considered solution is based on the idea of tensioned cable. If the cable was grasped by the ends and tensioned, it has a line shape. Since the position of the robot’s end-effectors known, the position of the cable is known as well. Such an approach is capable to place cable in cable ducts of switchgear. The considered solution has been tested experimentally on a real bilateral robotic setup.

Effect of laser welding on the titanium composite tensile bond strength

The aim of this study was to analyze the shear bond strength between commercially pure titanium, with and without laser welding, after airbone-particle abrasion (Al2O3) and 2 indirect composites. Sixty-four specimens were cast and divided into 2 groups with and without laser welding. Each group was divided in 4 subgroups, related to Al2O3 grain size: A - 250 µm; B - 180 µm; C- 110 µm; and D - 50 µm. Composite rings were formed around the rods and light polymerized using UniXS unit. Specimens were invested and their shear bond strength at failure was measured with a universal testing machine at a crosshead speed of 2.0 mm/min. Statistical analysis was carried out with ANOVA and Tukey's test (α=0.05). The highest bond strength means were recorded in 250 µm group without laser welding. The lowest shear bond strength means were recorded in 50 µm group with laser welding. Statistically significant differences (p<0.05) were found between all groups. In conclusion, airborne particle abrasion yielded significantly lower bond strength as the Al2O3 particle size decreased. Shear bond strength decreased in the laser welded specimens.

Robotic Resection of Intraductal Neoplasm of the Pancreas

Background: Minimally invasive techniques have been revolutionary and provide clinical evidence of decreased morbidity and comparable efficacy to traditional open surgery. Computer-assisted surgical devices have recently been approved for general surgical use. Aim: The aim of this study was to report the first known case of pancreatic resection with the use of a computer-assisted, or robotic, surgical device in Latin America. Patient and Methods: A 37-year-old female with a previous history of radical mastectomy for bilateral breast cancer due to a BRCA2 mutation presented with an acute pancreatitis episode. Radiologic investigation disclosed an intraductal pancreatic neoplasm located in the neck of the pancreas with atrophy of the body and tail. The main pancreatic duct was enlarged. The surgical decision was to perform a laparoscopic subtotal pancreatectomy, using the da Vinci (R) robotic system (Intuitive Surgical, Sunnyvale, CA). Five trocars were used. Pancreatic transection was achieved with vascular endoscopic stapler. The surgical specimen was removed without an additional incision. Results: Operative time was 240 minutes. Blood loss was minimal, and the patient did not receive a transfusion. The recovery was uneventful, and the patient was discharged on postoperative day 4. Conclusions: The subtotal laparoscopic pancreatic resection can safely be performed. The da Vinci robotic system allowed for technical refinements of laparoscopic pancreatic resection. Robotic assistance improved the dissection and control of major blood vessels due to three-dimensional visualization of the operative field and instruments with wrist-type end-effectors.

Coloured Petri nets and graphical simulation for the validation of a robotic cell in aircraft industry

This paper proposes a mixed validation approach based on coloured Petri nets and 3D graphic simulation for the design of supervisory systems in manufacturing cells with multiple robots. The coloured Petri net is used to model the cell behaviour at a high level of abstraction. It models the activities of each cell component and its coordination by a supervisory system. The graphical simulation is used to analyse and validate the cell behaviour in a 3D environment, allowing the detection of collisions and the calculation of process times. The motivation for this work comes from the aeronautic industry. The automation of a fuselage assembly process requires the integration of robots with other cell components such as metrological or vision systems. In this cell, the robot trajectories are defined by the supervisory system and results from the coordination of the cell components. The paper presents the application of the approach for an aircraft assembly cell under integration in Brazil. This case study shows the feasibility of the approach and supports the discussion of its main advantages and limits. (C) 2011 Elsevier Ltd. All rights reserved.

Continence, potency and oncological outcomes after robotic-assisted radical prostatectomy: early trifecta results of a high-volume surgeon

OBJECTIVE center dot To evaluate early trifecta outcomes after robotic-assisted radical prostatectomy (RARP) performed by a high-volume surgeon. PATIENTS AND METHODS center dot We evaluated prospectively 1100 consecutive patients who underwent RARP performed by one surgeon. In all, 541 men were considered potent before RARP; of these 404 underwent bilateral full nerve sparing and were included in this analysis. center dot Baseline and postoperative urinary and sexual functions were assessed using self-administered validated questionnaires. center dot Postoperative continence was defined as the use of no pads; potency was defined as the ability to achieve and maintain satisfactory erections for sexual intercourse > 50% of times, with or without the use of oral phosphodiesterase type 5 inhibitors; Biochemical recurrence (BCR) was defined as two consecutive PSA levels of > 0.2 ng/mL after RARP. center dot Results were compared between three age groups: Group 1, < 55 years, Group 2, 56-65 years and Group 3, > 65 years. RESULTS center dot The trifecta rates at 6 weeks, 3, 6, 12, and 18 months after RARP were 42.8%, 65.3%, 80.3%, 86% and 91%, respectively. center dot There were no statistically significant differences in the continence and BCR-free rates between the three age groups at all postoperative intervals analysed. center dot Nevertheless, younger men had higher potency rates and shorter time to recovery of sexual function when compared with older men at 6 weeks, 3, 6 and 12 months after RARP (P < 0.01 at all time points). center dot Similarly, younger men also had a shorter time to achieving the trifecta and had higher trifecta rates at 6 weeks, 3 and 6 months after RARP compared with older men (P < 0.01 at all time points). CONCLUSION center dot RARP offers excellent short-term trifecta outcomes when performed by an experienced surgeon. center dot Younger men had a shorter time to achieving the trifecta and higher overall trifecta rates when compared with older men at 6 weeks, 3 and 6 months after RARP.

Early Complication Rates in a Single-Surgeon Series of 2500 Robotic-Assisted Radical Prostatectomies: Report Applying a Standardized Grading System

Background: Perioperative complications following robotic-assisted radical prostatectomy (RARP) have been previously reported in recent series. Few studies, however, have used standardized systems to classify surgical complications, and that inconsistency has hampered accurate comparisons between different series or surgical approaches. Objective: To assess trends in the incidence and to classify perioperative surgical complications following RARP in 2500 consecutive patients. Design, setting, and participants: We analyzed 2500 patients who underwent RARP for treatment of clinically localized prostate cancer (PCa) from August 2002 to February 2009. Data were prospectively collected in a customized database and retrospectively analyzed. Intervention: All patients underwent RARP performed by a single surgeon. Measurements: The data were collected prospectively in a customized database. Complications were classified using the Clavien grading system. To evaluate trends regarding complications and radiologic anastomotic leaks, we compared eight groups of 300 patients each, categorized according the surgeon`s experience (number of cases). Results and limitations: Our median operative time was 90 min (interquartile range [IQR]: 75-100 min). The median estimated blood loss was 100 ml (IQR: 100-150 ml). Our conversion rate was 0.08%, comprising two procedures converted to standard laparoscopy due to robot malfunction. One hundred and forty complications were observed in 127 patients (5.08%). The following percentages of patients presented graded complications: grade 1, 2.24%; grade 2, 1.8%; grade 3a, 0.08%; grade 3b, 0.48%; grade 4a, 0.40%. There were no cases of multiple organ dysfunction or death (grades 4b and 5). There were significant decreases in the overall complication rates (p = 0.0034) and in the number of anastomotic leaks (p < 0.001) as the surgeon`s experience increased. Conclusions: RARP is a safe option for treatment of clinically localized PCa, presenting low complication rates in experienced hands. Although the robotic system provides the surgeon with enhanced vision and dexterity, proficiency is only accomplished with consistent surgical volume; complication rates demonstrated a tendency to decrease as the surgeon`s experience increased. (C) 2010 European Association of Urology. Published by Elsevier B. V. All rights reserved.

Robotic Surgery: History and Teaching Impact

Context: The purpose of this article is to review the history of robotic surgery, its impact on teaching as well as a description of historical and current robots used in the medical arena. Summary of evidence: Although the history of robots dates back to 2000 years or more, the last two decades have seen an outstanding revolution in medicine, due to all the changes that robotic surgery has made in the way of performing, teaching and practicing surgery. Conclusions: Robotic surgery has evolved into a complete and self-contained field, with enormous potential for future development. The results to date have shown that this technology is capable of providing good outcomes and quality care for patients. (C) 2011 AEU. Published by Elsevier Espana, S.L. All rights reserved.

Welding and rheomorphism of phonolitic fallout deposits from the Las Canadas caldera, Tenerife, Canary Islands

The Las Canadas caldera is a nested collapse caldera formed by the successive migration and collapse of shallow magmatic chambers. Among the pyroclastic products of this caldera are phonolitic fallout deposits that crop out in the caldera wall and on the extracaldera slopes. These deposits exhibit an uninterrupted facies gradation from nonwelded to lava-like and record continuous volcanic deposition. Densely welded and lava-like facies result from the extreme attenuation and complete homogenization of juvenile clasts that destroy original clast outlines and any evidence of fallout deposition. Agglutination contributes significantly to the final degree of flattening observed in the welded facies. After deposition, rheomorphic flowage occurs. Emplacement temperatures for one of the welding sequences are calculated from magmatic temperatures and a model of tephra cooling during fallout. Results are 486 degreesC for the nonwelded facies and 740 degreesC for the moderately welded facies. For the same welding sequence, a cooling time between 25 and 54 days is estimated from published experimental and computational data as the possible duration of welding and rheomorphism. Following deposition and agglutination, the lava-like pyroclastic facies had the rheological properties of viscous lavas and flowed down the outer slopes away from the caldera. Some lava-like masses detached from proximal areas to more distal regions. During deposition, the eruptive style evolved from Plinian fallout to fountain-fed spatter deposition. This evolution was accompanied by a decrease in explosive power and a lower height of the eruptive column, which produce higher emplacement temperatures and more effective heat retention of pyroclasts.

Hand-held robotic device for laparoscopic surgery and training

Laparoscopic surgery (LS) has revolutionized traditional surgical techniques introducing minimally invasive procedures for diagnosis and local therapies. LSs have undeniable advantages, such as small patient incisions, reduced postoperative pain and faster recovery. On the other hand, restricted vision of the anatomical target, difficult handling of the surgical instruments, restricted mobility inside the human body, need of dexterity to hand-eye coordination and inadequate and non-ergonomic surgical instruments may restrict LS only to more specialized surgeons. To overcome the referred limitations, this work presents a new robotic surgical handheld system – the EndoRobot. The EndoRobot was designed to be used in clinical practice or even as a surgical simulator. It integrates an electromechanical system with 3 degrees of freedom. Each degree can be manipulated independently and combined with different levels of sensitivity allowing fast and slow movements. As other features, the EndoRobot has battery power or external power supply, enables the use of bipolar radiofrequency to prevent bleeding while cutting and allows plug-and-play of the laparoscopic forceps for rapid exchange. As a surgical simulator, the system was also instrumented to measure and transmit, in real time, its position and orientation for a training software able to monitor and assist the trainee’s surgical movements.

Assessment of Laparoscopic Skills Performance: 2D Versus 3D Vision and Classic Instrument Versus New Hand-Held Robotic Device for Laparoscopy

Introduction and Objectives. Laparoscopic surgery has undeniable advantages, such as reduced postoperative pain, smaller incisions, and faster recovery. However, to improve surgeons’ performance, ergonomic adaptations of the laparoscopic instruments and introduction of robotic technology are needed. The aim of this study was to ascertain the influence of a new hand-held robotic device for laparoscopy (HHRDL) and 3D vision on laparoscopic skills performance of 2 different groups, naïve and expert. Materials and Methods. Each participant performed 3 laparoscopic tasks—Peg transfer, Wire chaser, Knot—in 4 different ways. With random sequencing we assigned the execution order of the tasks based on the first type of visualization and laparoscopic instrument. Time to complete each laparoscopic task was recorded and analyzed with one-way analysis of variance. Results. Eleven experts and 15 naïve participants were included. Three-dimensional video helps the naïve group to get better performance in Peg transfer, Wire chaser 2 hands, and Knot; the new device improved the execution of all laparoscopic tasks (P < .05). For expert group, the 3D video system benefited them in Peg transfer and Wire chaser 1 hand, and the robotic device in Peg transfer, Wire chaser 1 hand, and Wire chaser 2 hands (P < .05). Conclusion. The HHRDL helps the execution of difficult laparoscopic tasks, such as Knot, in the naïve group. Three-dimensional vision makes the laparoscopic performance of the participants without laparoscopic experience easier, unlike those with experience in laparoscopic procedures.