Determinadas peças cilíndricas internas exigem inspeção via súbito por dificuldades inerentes à peça ou de acesso a essas dimensões. O trabalho com esse tipo de instrumento exige operador especializado e em geral são medições demoradas e com alto nível de incerteza potencializada quando se trata de produção de médios e grandes lotes. Sabe-se que a medição acurada com baixos níveis de incerteza associada a tempos econômicos de inspeção são decisivos para o aumento da qualidade e produtividade da empresa, já que o conhecimento das dimensões é essencial para assegurar, que os componentes produzidos através dos diversos processos de manufatura estejam dentro das especificações. Este trabalho tem por objetivo apresentar o desenvolvimento de um sistema automatizado para a medição de diâmetros internos que simule a medição via comparador de diâmetros. Um robô industrial foi empregado como manipulador de transdutores de deslocamento do tipo LVDT e, substitui o operador humano. Para a realização das medidas, foi desenvolvido um programa computacional em linguagem Delphi, o que proporcionou a comunicação entre o microcomputador, LVDT e o sistema de controle do robô através de uma placa de aquisição do tipo AD/DA. Os valores medidos foram comparados com padrões metrológicos pertinentes. Os resultados foram efetivos e comprovaram a eficácia do sistema de medição proposto tanto técnica como economicamente. / Certain internal cylindrical surfaces require diameter inspection by means of bore gauges due to either shape-inherent difficulties or poor access to the measuring point. Measurements with such instruments, which call for skilled operator, are generally long and may present high uncertainty levels when inspecting mid-size or large part batches. Accurate measurements with low associated uncertainty and cost-effective inspection time are decisive to quality and productivity improvement, since dimensional information is essential to ensure that parts produced by several manufacturing processes lie within specifications. This work aims to present the development of an automated and dedicated diameter measuring system that simulates bore gauge inspection. An industrial robot, which was employed to manipulate inductive type displacement probes, replaces the human operator. In order to achieve measurements, a Delphi language object-oriented algorithm was developed to provide communication among displacement probes, a microcomputer and the robot control system, by means of an AD/DA acquisition board. Measured values were compared to pertinent metrological standards. The results were consistent and demonstrated the efficiency of the proposed measuring system, both technically and economically.

<p>All mechanical systems with moving parts are affected by friction, including industrial robots. Being able to design an accurate friction model would further increase the performance of todays robots. Friction is a complex dynamic phenomena that is constantly changing depending on the state and environment of the robot. It is therefore beneficial to update the parameters of the friction model online. An estimate of the friction will be made using the feedback control signal with the help of a feedforward control scheme in a two axis simulation setup. The friction estimate is then used for an offline identification of three friction model parameters in a static Lugre friction model. Improvements on the identification will be done by introducing some shut-off rules that will improve the estimate. The normalized least mean square method (NLMS) will then be used to update the parameters online. A simulation of friction compensation with a fixed friction model, and with an adaptive friction model will be studied. The method will also be simulated using experimental data taken from a real industrial robot.</p>

<p>The goal of this Master thesis has on the one hand been to create a simulation environment for robots, where not only the simulations in this work can be performed, but also similar robot simulations, and on the other hand to study regulators that can increase the possibilities of rejecting disturbances on an industrial robot. The robot model used has three degrees of freedom, corresponding to the three main links on ABB:s IRB7600. </p><p>The simulation environment is created using Matlab, Simulink, and Robotics Toolbox. It is constructed in a general way and can be used for simulations of other robot objects created in Robotics Toolbox. </p><p>A gain scheduling is added to the LQ-regulator, where the feedback matrix is varied depending on the arm position in the workspace. The gain scheduling is implemented along a reference path in the workspace, around which the simulations and frequency analyses are performed. </p><p>The regulators that have been tested are a PID-regulator, a gain scheduled LQ-regulator, a gain scheduled LQ-regulator with reconstructed states, and finally a fix LQ-regulator with reconstructed states. Results from the tests show that the gain scheduling LQ-regulator is the one that yields the best rejection of disturbances, but the corresponding regulator with reconstructed states, which is more realistic, performs nearly as well. The model based regulators are, however, significantly better when it comes to rejecting disturbances than the PID-regulator.</p>

<p>This thesis studies path generation for industrial robots of six degrees of freedom. A path is defined by connection of simple geometrical objects like arcs and straight lines. About each point at which the objects connect, a region, henceforth called a zone, is defined in which deviation from the defined path is permitted. The zone allows the robot to follow the path at a constant speed, but the acceleration needed may vary. </p><p>Some means of calculating the zone path as to make the acceleration continuous will be presented. In joint space the path is described by the use of cubic splines. The transformation of the Cartesian path to paths in joint space will be examined. Discontinuities in the second order derivatives will appear between the splines. </p><p>A few examples of different zone path calculations will be presented where the resulting spline functions are compared with respect to their first and second order derivatives. An investigation of the number of spline functions needed when, given an upper limit of deviation, the transformation back to Cartesian coordinates is made.</p>

<p>Dagens robotindustri har som mål att bygga billigare och lättare robotar, vilket ger allt vekare robotar. Denna rapport studerar identifiering och reglering med en extra armsensor – accelerometer – på en flexibel industrirobot. Studien har skett både simulerat och experimentellt på en industrirobot.</p><p>Vid identifiering med accelerometer befinner sig accelerometern i ett roterande koordinatsystem. Denna rapport presenterar en kompenseringsalgoritm för att transformera signalerna från det roterande koordinatsystemet till ett rumsfast koordinatsystem.</p><p>I denna rapport presenteras regulatorstrukturerna I-PID, II^2-PID och LQG, vilka alla återkopplar motorvinkel och armvinkelacceleration. Som referens har PID-regulator med endast motorvinkelåterkoppling använts. Simuleringsmässigt studeras regulatorerna både på ett fyrmassesystem och på en treaxlig modell av roboten. Vid reglering av fyrmassesystemet ger LQG-regulatorn bäst prestanda med avseende på minimerande av överslängar och insvägningstid. Vid reglering av den treaxliga modellen uppkommer endast små skillnader mellan reglermetoderna. Experimentellt studeras endast I-PID-regulatorn, beroende på dess enkelhet i strukturen och den lilla prestandaskillnaden simulerat mot övriga regulatorer. Experimenten visar att prestanda (minskade överslängar och insvägningstider) förbättras vid användandet av en I-PID-regulator istället för PID-regulatorn och att I-PID-regulatorn har robust prestanda med avseende på modellvariationer i framkopplingsmodellen och robust stabilitet när återkopplingsförstärkningen kan ökas utan att instabilitet uppstår.</p> / <p>One of the goals for robot industry today is to decrease expenses of material, which makes more flexible robots. This thesis studies identification and control with an extra arm sensor – accelerometer – on a flexible industrial robot. The results are both from simulations and experiments of an industrial robot.</p><p>In identification the accelerometer is in a revolving coordinate system. An algorithm of compensation for transforming the signals in the revolving frame to the base frame is presented.</p><p>The introduced regulators I-PID, II^2-PID and LQG will be used, which all feedback motor angle and arm angle acceleration. A PID-regulator with only motor angle feedback has been used as reference. The regulators are simulated on a fourmass-system and on a three axis model of the robot. In control of the fourmass-system the LQG-regulator gives the best performance, according to minimized overshoots and settling times. In control of the three axis model only smaller differences appear. Experimental is only the I-PID-regulator studied, because of its simple structure and simulated small differences of performance with respect to other regulators. The experiments show that the I-PID-regulator has better nominal and robust performance (minimized overshoots and settling times) compared to the PID-regulator.</p>

All mechanical systems with moving parts are affected by friction, including industrial robots. Being able to design an accurate friction model would further increase the performance of todays robots. Friction is a complex dynamic phenomena that is constantly changing depending on the state and environment of the robot. It is therefore beneficial to update the parameters of the friction model online. An estimate of the friction will be made using the feedback control signal with the help of a feedforward control scheme in a two axis simulation setup. The friction estimate is then used for an offline identification of three friction model parameters in a static Lugre friction model. Improvements on the identification will be done by introducing some shut-off rules that will improve the estimate. The normalized least mean square method (NLMS) will then be used to update the parameters online. A simulation of friction compensation with a fixed friction model, and with an adaptive friction model will be studied. The method will also be simulated using experimental data taken from a real industrial robot.

Industrial robots have been used for a long time in the industry. Despite this thedevelopment of advanced force control system using industrial robots is relativelylimited. Using force controlled robot systems expands the possibility of what canbe done with industrial robots.Previously a force feedback system for a standard industrial robot from ABBhas been developed. The system is developed towards the aircraft industry, where amounted drill machine on the robot has to fulfill the requirements in robot drillingin aircraft structures. This thesis presents experimental results and improvementsof this industrial robot system. Mechanical modifications and tests of a new endeffector are analyzed.

The goal of this Master thesis has on the one hand been to create a simulation environment for robots, where not only the simulations in this work can be performed, but also similar robot simulations, and on the other hand to study regulators that can increase the possibilities of rejecting disturbances on an industrial robot. The robot model used has three degrees of freedom, corresponding to the three main links on ABB:s IRB7600. The simulation environment is created using Matlab, Simulink, and Robotics Toolbox. It is constructed in a general way and can be used for simulations of other robot objects created in Robotics Toolbox. A gain scheduling is added to the LQ-regulator, where the feedback matrix is varied depending on the arm position in the workspace. The gain scheduling is implemented along a reference path in the workspace, around which the simulations and frequency analyses are performed. The regulators that have been tested are a PID-regulator, a gain scheduled LQ-regulator, a gain scheduled LQ-regulator with reconstructed states, and finally a fix LQ-regulator with reconstructed states. Results from the tests show that the gain scheduling LQ-regulator is the one that yields the best rejection of disturbances, but the corresponding regulator with reconstructed states, which is more realistic, performs nearly as well. The model based regulators are, however, significantly better when it comes to rejecting disturbances than the PID-regulator.

This thesis studies path generation for industrial robots of six degrees of freedom. A path is defined by connection of simple geometrical objects like arcs and straight lines. About each point at which the objects connect, a region, henceforth called a zone, is defined in which deviation from the defined path is permitted. The zone allows the robot to follow the path at a constant speed, but the acceleration needed may vary. Some means of calculating the zone path as to make the acceleration continuous will be presented. In joint space the path is described by the use of cubic splines. The transformation of the Cartesian path to paths in joint space will be examined. Discontinuities in the second order derivatives will appear between the splines. A few examples of different zone path calculations will be presented where the resulting spline functions are compared with respect to their first and second order derivatives. An investigation of the number of spline functions needed when, given an upper limit of deviation, the transformation back to Cartesian coordinates is made.

Dagens robotindustri har som mål att bygga billigare och lättare robotar, vilket ger allt vekare robotar. Denna rapport studerar identifiering och reglering med en extra armsensor – accelerometer – på en flexibel industrirobot. Studien har skett både simulerat och experimentellt på en industrirobot. Vid identifiering med accelerometer befinner sig accelerometern i ett roterande koordinatsystem. Denna rapport presenterar en kompenseringsalgoritm för att transformera signalerna från det roterande koordinatsystemet till ett rumsfast koordinatsystem. I denna rapport presenteras regulatorstrukturerna I-PID, II^2-PID och LQG, vilka alla återkopplar motorvinkel och armvinkelacceleration. Som referens har PID-regulator med endast motorvinkelåterkoppling använts. Simuleringsmässigt studeras regulatorerna både på ett fyrmassesystem och på en treaxlig modell av roboten. Vid reglering av fyrmassesystemet ger LQG-regulatorn bäst prestanda med avseende på minimerande av överslängar och insvägningstid. Vid reglering av den treaxliga modellen uppkommer endast små skillnader mellan reglermetoderna. Experimentellt studeras endast I-PID-regulatorn, beroende på dess enkelhet i strukturen och den lilla prestandaskillnaden simulerat mot övriga regulatorer. Experimenten visar att prestanda (minskade överslängar och insvägningstider) förbättras vid användandet av en I-PID-regulator istället för PID-regulatorn och att I-PID-regulatorn har robust prestanda med avseende på modellvariationer i framkopplingsmodellen och robust stabilitet när återkopplingsförstärkningen kan ökas utan att instabilitet uppstår. / One of the goals for robot industry today is to decrease expenses of material, which makes more flexible robots. This thesis studies identification and control with an extra arm sensor – accelerometer – on a flexible industrial robot. The results are both from simulations and experiments of an industrial robot. In identification the accelerometer is in a revolving coordinate system. An algorithm of compensation for transforming the signals in the revolving frame to the base frame is presented. The introduced regulators I-PID, II^2-PID and LQG will be used, which all feedback motor angle and arm angle acceleration. A PID-regulator with only motor angle feedback has been used as reference. The regulators are simulated on a fourmass-system and on a three axis model of the robot. In control of the fourmass-system the LQG-regulator gives the best performance, according to minimized overshoots and settling times. In control of the three axis model only smaller differences appear. Experimental is only the I-PID-regulator studied, because of its simple structure and simulated small differences of performance with respect to other regulators. The experiments show that the I-PID-regulator has better nominal and robust performance (minimized overshoots and settling times) compared to the PID-regulator.