Incorporation of the influences of kinematics parameters and joints tilting for the calibration of serial robotic manipulators

Serial robotic manipulators are calibrated to improve and restore their accuracy and repeatability. Kinematics parameters calibration of a robot reduces difference between the model of a robot in the controller and its actual mechanism to improve accuracy. Kinematics parameter’s error identification in the standard kinematics calibration has been configuration independent which does not consider the influence of kinematics parameter on robot tool pose accuracy for a given configuration. This research analyses the configuration dependent influences of kinematics parameters error on pose accuracy of a robot. Based on the effect of kinematics parameters, errors in the kinematics parameters are identified. Another issue is that current kinematics calibration models do not incorporate the joints tilting as a result of joint clearance, backlash, and flexibility, which is critical to the accuracy of serial robotic manipulators, and therefore compromises a pose accuracy. To address this issue which has not been carefully considered in the literature, this research suggested an approach to model configuration dependent joint tilting and presents a novel approach to encapsulate them in the calibration of serial robotic manipulators. The joint tilting along with the kinematics errors are identified and compensated in the kinematics model of the robot. Both conventional and proposed calibration approach are tested experimentally, and the calibration results are investigated to demonstrate the effectiveness of this research. Finally, the improvement in the trajectory tracking accuracy of the robot has been validated with the help of proposed low-cost measurement set-up.Thesis (M.Phil.) (Research by Publication) -- University of Adelaide, School of Mechanical Engineering , 201

Characterizing the specifications of a 6 DoF industrial robotic arm

En aquest projecte es presenta l’estudi i la caracterització de les especificacions més importants del braços robòtics de sis graus de llibertat. El document presenta un protocol replicable de proves vàlid per a qualsevol tipus de robot industrial, però està centrat en el braç robòtic CM607-L de CM robotics. L’objectiu principal del projecte és crear i presentar un protocol de tests i alguns possibles equipaments necessaris per realitzar les proves per a què en un futur es pugui utilitzar en la caracterització de diversos robots, tot i això es crearan alguns setups i es realitzaran de forma pràctica algunes de les proves per comprovar que el protocol és correcte. Degut a la curta durada del projecte, i la gran quantitat de proves necessàries per a la total caracterització del robot, en aquest document es presentaran els resultats de les proves de velocitat de cada eix, la velocitat total i el màxim rang de funcionament de cada eix. El document està dividit en diverses seccions. En el primer apartat es poden trobar la motivació i els objectius del projecte, el segon apartat comenta les principals característiques del robot utilitzat (CM607-L), el tercer apartat presenta les diferents alternatives estudiades i el protocol de test definitiu, el quart apartat mostra els setups dissenyats per a realitzar les proves pràctiques i en el cinquè apartat estan recollits els resultats de les proves. Finalment, es poden trobar l’estudi ambiental, l’econòmic i les conclusions.En este proyecto se presenta el estudio y caracterización de las especificaciones más importantes de los brazos robóticos de seis grados de libertad. El documento presenta un protocolo replicable de pruebas válido para cualquier tipo de robot industrial, pero está centrado en el brazo robótico CM607-L de CM robotics. El objetivo principal del proyecto es crear y presentar un protocolo de tests y algunos posibles equipamientos necesarios para realizar las pruebas para que en un futuro se pueda utilizar en la caracterización de varios robots, sin embargo, se crearán algunos setups y se realizarán de forma práctica algunas de las pruebas para comprobar que el protocolo es correcto. Debido a la corta duración del proyecto, y la gran cantidad de pruebas necesarias para la total caracterización del robot, en este documento se presentarán los resultados de las pruebas de velocidad de cada eje, la velocidad total y el máximo rango de funcionamiento de cada eje. El documento está dividido en varias secciones. En el primer apartado se puede encontrar la motivación y los objetivos del proyecto, el segundo apartado comenta las principales características del robot utilizado (CM607-L), el tercer apartado presenta las diferentes alternativas estudiadas y el protocolo de test definitivo, el cuarto apartado muestra los setups diseñados para realizar las pruebas prácticas y en el quinto apartado están recogidos los resultados de las pruebas. Por último, se pueden encontrar el estudio ambiental, el económico y las conclusiones.This project presents the study and characterization of the most important specifications of the robotic arm with six degrees of freedom. The paper presents a replicable test protocol valid for any type of industrial robot, but is focused on the CM robotics CM607-L robotic arm. The main objective of the project is to create and present a test protocol and some possible equipment needed to carry out the tests so that in the future it can be used in the characterization of several robots, although some setups will be created and carried out to practice some of the tests to verify that the protocol is correct. Due to the short duration of the project, and the large number of tests necessary for the full characterization of the robot, this document will present the results of the speed tests of each axis, the total speed and the maximum operating range of each shaft The document is divided into several sections. In the first section you can find the motivation and objectives of the project, the second section comments on the main characteristics of the robot used (CM607-L), the third section presents the different alternatives studied and the definitive test protocol, the fourth section shows the setups designed to carry out the practical tests and in the fifth section the results of the tests are collected. Finally, you can find the environmental study, the economic study and the conclusions

Computer hardware and software for robotic control

The KSC has implemented an integrated system that coordinates state-of-the-art robotic subsystems. It is a sensor based real-time robotic control system performing operations beyond the capability of an off-the-shelf robot. The integrated system provides real-time closed loop adaptive path control of position and orientation of all six axes of a large robot; enables the implementation of a highly configurable, expandable testbed for sensor system development; and makes several smart distributed control subsystems (robot arm controller, process controller, graphics display, and vision tracking) appear as intelligent peripherals to a supervisory computer coordinating the overall systems

A framework for flexible integration in robotics and its applications for calibration and error compensation

Robotics has been considered as a viable automation solution for the aerospace industry to address manufacturing cost. Many of the existing robot systems augmented with guidance from a large volume metrology system have proved to meet the high dimensional accuracy requirements in aero-structure assembly. However, they have been mainly deployed as costly and dedicated systems, which might not be ideal for aerospace manufacturing having low production rate and long cycle time. The work described in this thesis is to provide technical solutions to improve the flexibility and cost-efficiency of such metrology-integrated robot systems. To address the flexibility, a software framework that supports reconfigurable system integration is developed. The framework provides a design methodology to compose distributed software components which can be integrated dynamically at runtime. This provides the potential for the automation devices (robots, metrology, actuators etc.) controlled by these software components to be assembled on demand for various assembly applications. To reduce the cost of deployment, this thesis proposes a two-stage error compensation scheme for industrial robots that requires only intermittent metrology input, thus allowing for one expensive metrology system to be used by a number of robots. Robot calibration is employed in the first stage to reduce the majority of robot inaccuracy then the metrology will correct the residual errors. In this work, a new calibration model for serial robots having a parallelogram linkage is developed that takes into account both geometric errors and joint deflections induced by link masses and weight of the end-effectors. Experiments are conducted to evaluate the two pieces of work presented above. The proposed framework is adopted to create a distributed control system that implements calibration and error compensation for a large industrial robot having a parallelogram linkage. The control system is formed by hot-plugging the control applications of the robot and metrology used together. Experimental results show that the developed error model was able to improve the 3 positional accuracy of the loaded robot from several millimetres to less than one millimetre and reduce half of the time previously required to correct the errors by using only the metrology. The experiments also demonstrate the capability of sharing one metrology system to more than one robot

Visual perception system and method for a humanoid robot

A robotic system includes a humanoid robot with robotic joints each moveable using an actuator(s), and a distributed controller for controlling the movement of each of the robotic joints. The controller includes a visual perception module (VPM) for visually identifying and tracking an object in the field of view of the robot under threshold lighting conditions. The VPM includes optical devices for collecting an image of the object, a positional extraction device, and a host machine having an algorithm for processing the image and positional information. The algorithm visually identifies and tracks the object, and automatically adapts an exposure time of the optical devices to prevent feature data loss of the image under the threshold lighting conditions. A method of identifying and tracking the object includes collecting the image, extracting positional information of the object, and automatically adapting the exposure time to thereby prevent feature data loss of the image

Vision technology/algorithms for space robotics applications

The thrust of automation and robotics for space applications has been proposed for increased productivity, improved reliability, increased flexibility, higher safety, and for the performance of automating time-consuming tasks, increasing productivity/performance of crew-accomplished tasks, and performing tasks beyond the capability of the crew. This paper provides a review of efforts currently in progress in the area of robotic vision. Both systems and algorithms are discussed. The evolution of future vision/sensing is projected to include the fusion of multisensors ranging from microwave to optical with multimode capability to include position, attitude, recognition, and motion parameters. The key feature of the overall system design will be small size and weight, fast signal processing, robust algorithms, and accurate parameter determination. These aspects of vision/sensing are also discussed

Two-Stage Transfer Learning for Heterogeneous Robot Detection and 3D Joint Position Estimation in a 2D Camera Image using CNN

Collaborative robots are becoming more common on factory floors as well as regular environments, however, their safety still is not a fully solved issue. Collision detection does not always perform as expected and collision avoidance is still an active research area. Collision avoidance works well for fixed robot-camera setups, however, if they are shifted around, Eye-to-Hand calibration becomes invalid making it difficult to accurately run many of the existing collision avoidance algorithms. We approach the problem by presenting a stand-alone system capable of detecting the robot and estimating its position, including individual joints, by using a simple 2D colour image as an input, where no Eye-to-Hand calibration is needed. As an extension of previous work, a two-stage transfer learning approach is used to re-train a multi-objective convolutional neural network (CNN) to allow it to be used with heterogeneous robot arms. Our method is capable of detecting the robot in real-time and new robot types can be added by having significantly smaller training datasets compared to the requirements of a fully trained network. We present data collection approach, the structure of the multi-objective CNN, the two-stage transfer learning training and test results by using real robots from Universal Robots, Kuka, and Franka Emika. Eventually, we analyse possible application areas of our method together with the possible improvements.Comment: 6+n pages, ICRA 2019 submissio