scholarly journals Evaluation of Kinematic and Compliance Calibration of Serial Articulated Industrial Manipulators

2021 ◽  
Vol 15 (5) ◽  
pp. 567-580
Author(s):  
Soichi Ibaraki ◽  
Nikolas Alexander Theissen ◽  
Andreas Archenti ◽  
Md. Moktadir Alam ◽  
◽  
...  
Keyword(s):  
Industrial Robots ◽  
Future Research ◽  
Positioning Accuracy ◽  
Model Based ◽  
Working Space ◽  
Industrial Manipulators ◽  
Compliant Robot ◽  
Kinematic Models ◽  
Technical Issues ◽  
New Applications

As long as industrial robots are programmed by teach programming, their positioning accuracy is unimportant. With a wider implementation of offline programming and new applications such as machining, ensuring a higher positioning accuracy of industrial robots over the entire working space has become very important. In this paper, we first review the measurement schemes of end effector poses. We then outline kinematic models of serial articulated industrial manipulators to quantify the positioning accuracy with a focus on the extension of the classical Denavit-Hartenberg (DH) models to include rotary axis error motions. Subsequently, we expand the discussion on kinematic models to compliant robot models. The review highlights compliance models that are applied to calculate the elastic deformation produced by forces, namely gravity and external loads. Model-based numerical compensation plays an important role in machine tool control. This paper aims to present state-of-the-art technical issues and future research directions for the implementation of model-based numerical compensation schemes for industrial robots.

A new underwater positioning model based on average sound speed

2021 ◽  
pp. 1-17
Author(s):  
Yixu Liu ◽  
Xiushan Lu ◽  
Shuqiang Xue ◽  
Shengli Wang
Keyword(s):  
Efficient Algorithm ◽  
Sound Speed ◽  
Incident Angle ◽  
Function Model ◽  
Positioning Accuracy ◽  
Correction Model ◽  
Model Based ◽  
Underwater Positioning ◽  
Speed Function ◽  
The Relationship

Abstract The layout of seafloor datum points is the key to constructing the seafloor geodetic datum network, and a reliable underwater positioning model is the prerequisite for achieving precise deployment of the datum points. The traditional average sound speed positioning model is generally adopted in underwater positioning due to its simple and efficient algorithm, but it is sensitive to incident angle related errors, which lead to unreliable positioning results. Based on the relationship between incident angle and sound speed, the sound speed function model considering the incident angle has been established. Results show that the accuracy of positioning is easily affected by errors related to the incident angle; the new average sound speed correction model based on the incident angle proposed in this paper is used to significantly improve the underwater positioning accuracy.

Schwingungsanalyse an Industrierobotern*/Vibration analysis of industrial robots

2019 ◽  
Vol 109 (09) ◽  
pp. 656-661
Author(s):  
A. Karim ◽  
C. Michalkowski ◽  
A. Lechler ◽  
A. Verl
Keyword(s):  
Modal Analysis ◽  
Active Control ◽  
Normal Mode ◽  
Vibration Analysis ◽  
Industrial Robots ◽  
Vibration Exciter ◽  
Dynamic Vibration ◽  
Vibration Behavior ◽  
Working Space ◽  
Electromagnetic Vibration

Dieser Beitrag untersucht experimentell das dynamische Schwingverhalten eines „KR-500–3 MT“ von Kuka mittels eines elektromagnetischen Schwingerregers (Shaker) an insgesamt 28 Messposen im Arbeitsraum. Diese Untersuchungsmethode ist neuartig, da die Ergebnisse mit einer Modalanalyse mit Impulshammeranregung verglichen werden. Ab der vierten Eigenmode entstehen Unterschiede aufgrund der Anregungsform. Zudem wird an jeder Pose eine Messung mit angezogener Motorbremse und eine mit aktiver Regelung durchgeführt und miteinander verglichen.   This paper explores experimentally the dynamic vibration behavior of a Kuka KR-500 MT, using an electromagnetic vibration exciter (shaker) on a total of 28 measuring poses in the working space. As such studies are not known, the results are compared to a modal analysis with impulse hammer excitation. Starting from the fourth normal mode, differences arise due to the form of excitation. Both measurements are performed and compared with each other on each pose with brakes applied as well as with active control.

Roboterbasierte spanende Bearbeitung*/Robot-Based Milling Operation. Machine Learning Algorithm for a model-based feed-forward torque control

2019 ◽  
Vol 109 (05) ◽  
pp. 352-357
Author(s):  
C. Brecher ◽  
L. Gründel ◽  
L. Lienenlüke ◽  
S. Storms
Keyword(s):  
Machine Learning ◽  
Position Control ◽  
Learning Algorithm ◽  
Milling Process ◽  
Industrial Robots ◽  
Torque Control ◽  
Feed Forward ◽  
Control Loops ◽  
Model Based ◽  
Machine Learning Approach

Die Lageregelung von konventionellen Industrierobotern ist nicht auf den dynamischen Fräsprozess ausgelegt. Eine Möglichkeit, das Verhalten der Regelkreise zu optimieren, ist eine modellbasierte Momentenvorsteuerung, welche in dieser Arbeit aufgrund vieler Vorteile durch einen Machine-Learning-Ansatz erweitert wird. Hierzu wird die Umsetzung in Matlab und die simulative Evaluation erläutert, die im Anschluss das Potenzial dieses Konzeptes bestätigt.   The position control of conventional industrial robots is not designed for the dynamic milling process. One possibility to optimize the behavior of the control loops is a model-based feed-forward torque control which is supported by a machine learning approach due to many advantages. The implementation in Matlab and the simulative evaluation are explained, which subsequently confirms the potential of this concept.

scholarly journals Method of cryptologic data transformations

2020 ◽  
Keyword(s):  
Infinite Number ◽  
High Speed ◽  
Communication Theory ◽  
Quantum Computer ◽  
Quantitative Information ◽  
Future Research ◽  
Basic Work ◽  
Analog Approach ◽  
Technical Issues ◽  
Discrete Theory

Countering a quantum computer in the process of illegal ultra-high-speed decryption of messages is technically feasible. Information owner must oppose the competitor's computer with tasks, the solution of which requires an infinite number of operations during decryption. For example, the dependence of functions on an infinite number of informative features. The owner encrypts by integrating the functions, the recipient decrypts by solving the integral equations. It is not a discrete but an analog approach that prevails here. The basis for the implementation of this approach was created by Polish scientists. Mathematician Stefan Banach (1892-1945), who created modern functional analysis, and Marian Mazur (1909-1983), the author of " The Qualitative Theory of Information". Their theory was created in contrast with the "Quantitative Information Theory". Cryptologists who have devoted their whole lives to improving the "discrete" theory and found themselves close to power (and finance), try not to recall that Claude Shannon in his basic work "Communication Theory of Secrecy Systems" more than once emphasized the discrete focus of his developments anticipating future research on the specific limitations of his work adapted to the communication theory. Forgetting about the unlimited speeds and amounts of memory of quantum computers the orthodox talk about redundancy and further purely technical issues, including administrative leverages for counteracting against opponents. It is impossible to stop the progress of science. Experiments have shown the reality of creating such post-quantum-level cryptographic systems.

scholarly journals Kinematic Modeling of Six-Axis Industrial Robot and its Parameter Identification: A Tutorial

2021 ◽  
Vol 15 (5) ◽  
pp. 599-610
Author(s):  
Md. Moktadir Alam ◽  
◽  
Soichi Ibaraki ◽  
Koki Fukuda
Keyword(s):  
Present Model ◽  
Industrial Robot ◽  
Local Coordinate System ◽  
Kinematic Model ◽  
Kinematic Modeling ◽  
Positioning Accuracy ◽  
Rotary Axis ◽  
Model Based ◽  
Absolute Positioning ◽  
The Absolute

In advanced industrial applications, like machining, the absolute positioning accuracy of a six-axis robot is indispensable. To improve the absolute positioning accuracy of an industrial robot, numerical compensation based on positioning error prediction by the Denavit and Hartenberg (D-H) model has been investigated extensively. The main objective of this study is to review the kinematic modeling theory for a six-axis industrial robot. In the form of a tutorial, this paper defines a local coordinate system based on the position and orientation of the rotary axis average lines, as well as the derivation of the kinematic model based on the coordinate transformation theory. Although the present model is equivalent to the classical D-H model, this study shows that a different kinematic model can be derived using a different definition of the local coordinate systems. Subsequently, an algorithm is presented to identify the error sources included in the kinematic model based on a set of measured end-effector positions. The identification of the classical D-H parameters indicates a practical engineering application of the kinematic model for improving a robot’s positioning accuracy. Furthermore, this paper presents an extension of the present model, including the angular positioning deviation of each rotary axis. The angular positioning deviation of each rotary axis is formed as a function of the axis’ command angles and the direction of its rotation to model the effect of the rotary axis backlash. The identification of the angular positioning deviation of each rotary axis and its numerical compensation are presented, along with their experimental demonstration. This paper provides an essential theoretical basis for the error source diagnosis and error compensation of a six-axis robot.

Development of a Simulation Model for Optimization of Business Process

2018 ◽  
pp. 26-42
Keyword(s):  
Simulation Model ◽  
Model Validation ◽  
Business Process ◽  
Research Question ◽  
Future Research ◽  
The Novel ◽  
Model Based ◽  
Model Validity ◽  
Proposed Model ◽  
New Research

Optimization of business process assists in efficient organization of business process. For the success of optimization of business process, a simulation model based on gap processes for the analysis of buyers' burstiness in business process has been proposed. However, the model has to be validated. The aim of the research is to implement a validation approach to the simulation model based on gap processes for the optimization of business process underpinning elaboration of a new research question on the model validity. The meaning of the key concepts of “validation,” “model validation,” and “model validation approach” is studied. The results of the present research show that the application of real system measurements validates the simulation model for the optimization of business process. The novel contribution of the manuscript is revealed in the newly created research question on the proposed model validity. Directions of future research are proposed.

Putting It All Together

2020 ◽  
pp. 149-168
Author(s):  
Nicole Baerg
Keyword(s):  
Central Bank ◽  
Future Research ◽  
Inflation Expectations ◽  
Economic News ◽  
New Applications ◽  
Transparency And Accountability

The concluding chapter summarizes the key findings in the manuscript and discusses three main contributions of the book. First, the book shows that variation in the preferences of committee members, whether members have aligned or opposed inflation preferences, affects the content of central bank communications. Second, it shows that changes in the content of central bank announcements impact households’ inflation expectations. Third, it shows that more precise economic news attenuates inflation expectations, helping to stabilize inflation. The chapter then relates these findings to broader discussion on central bank design, transparency, and accountability. The author argues that having greater preference diversity on central bank committees ensures more horizontal accountability as well as inflation stability. The chapter concludes with a number of ideas for future research, new applications, and extensions.

scholarly journals P42 External validation of model-based dosing guidelines for vancomycin, gentamicin and tobramycin in critically ill children

2019 ◽  
Vol 104 (6) ◽  
pp. e34.2-e34
Author(s):  
S Hartman ◽  
S Zwaag ◽  
L Orriëns ◽  
T Poel ◽  
M de Hoop - Sommen ◽  
...  
Keyword(s):  
Critically Ill ◽  
Clinical Laboratory ◽  
External Validation ◽  
Interindividual Variation ◽  
Critically Ill Children ◽  
Target Range ◽  
Future Research ◽  
Target Attainment ◽  
Model Based ◽  
Trough Concentrations

BackgroundPharmacokinetic models are frequently used to simulate dosing strategies for special populations, including critically ill children. The Dutch Pediatric Formulary (DPF) partially bases its guidelines on these models. However, prospective validation of updated dosing regimens is rare. We aimed to identify target attainment and safety of vancomycin, gentamicin and tobramycin after a dose update in the DPF for critically ill neonates and children.MethodsRetropsective cohort study in PICU and NICU patients receiving vancomycin, gentamicin or tobramycin between January 2015 and March 2017 in 2 university hospitals. Demographic clinical laboratory and TDM-data were collected. Target (steady state) trough concentrations for vancomycin, gentamicin and tobramycin used were 10–15, ≤1 and ≤1 mg/l, respectively. Target gentamicin peak concentrations used were 8–12 mg/l.Results486 patients were included in total (165 vancomycin, 97 gentamicin and 224 tobramycin). Trough concentrations of vancomycin, gentamicin and tobramycin were within the target range in 37.5%, 85.3% and 77.2% of patients, respectively. Target attainment of gentamicin peak concentrations in NICU patients was 31%. Non-target trough concentrations were most prevalent in term NICU patients (vancomycin 70%, gentamicin 26% and tobramycin 36.8%). Gentamicin peak concentrations were subtherapeutic in 91% and 45.5% for term and preterm NICU patients, respectively. Creatinine concentrations correlated positively with antibiotic concentrations (correlation coefficient range 0.46–0.54, p≤0.01 in all cohorts).ConclusionDespite recent model-based dosing alterations, sub- and supratherapeutic concentrations of vancomycin, gentamicin and tobramycin are still frequent in critically ill children. Linear dose alterations did offer improvements in target attainment, but did not fully address all relevant covariates that contribute to the large interindividual variation in clearance and/or volume of distribution in these patients. Creatinine clearance was consistently correlated with concentrations of all 3 drugs, but future research is needed to identify whether including this parameter in dosing can improve target attainment and safety.Disclosure(s)Nothing to disclose

Increasing the Performability of Wireless Web Services

2009 ◽  
pp. 518-528
Author(s):  
Wenbing Zhao
Keyword(s):  
Wireless Communication ◽  
Web Services ◽  
Mobile Devices ◽  
Future Research ◽  
Battery Life ◽  
Research Directions ◽  
Computing Power ◽  
Network Bandwidth ◽  
Technical Issues ◽  
Future Research Directions

Wireless Web services are becoming a reality, if they have not already. The unique characteristics of the mobile devices and wireless communication medium, such as limited computing power, limited network bandwidth, limited battery life, unpredictable online time, mobility, and so forth,, imply that the infrastructure for wireless Web services will be very different from its wired counterpart. This chapter discusses the challenges and the stateof- the-art solutions to ensure highly performable wireless Web services. In particular, this chapter’s focus is on three technical issues: optimization of the wireless Web services messaging protocol, caching, and fault tolerance. Finally, limitations of the current approaches and an outline of future research directions on wireless Web services are also discussed.

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