Design of a Flexure-Based Active Fixture System for Precision Robotic Deburring

2018 ◽  
Author(s):  
Jacob Beck ◽  
Burak Sencer ◽  
Ravi Balasubramanian ◽  
Jordan Meader
Keyword(s):  
High Resolution ◽  
Force Control ◽  
Cutting Forces ◽  
Robotic Manipulators ◽  
Positioning System ◽  
Motion Generation ◽  
Positioning Accuracy ◽  
High Compliance ◽  
Dual Stage ◽  
Fixture System

This paper presents on the design, prototyping and testing of a flexure-based active workpiece fixture system for precision robotic deburring. Current industrial robotic manipulators suffer from poor positioning accuracy, which makes precision tasks such as deburring, polishing and grinding challenging. Together, the robotic manipulator and the proposed active work fixture will create a dual-stage positioning system for precision tasks where position/force control is crucial. The main application is robotic deburring, which demands positioning accuracy and high compliance over large cutting forces. This first prototype active fixture system is designed as a planar motion table that is supported by parallel flexures, driven by voice-coil actuators, and uses high-resolution laser displacement pickups facilitate accurate motion generation with great backdrivability for force control. The theory behind the proposed design is shown, and a prototype is then used to validate performance. Overall the prototype flexure stage achieves a total stroke of 1 mm and a bandwidth of 21 Hz.

Investigations on Motion Precision of High-Resolution Stereolithography System

2011 ◽  
Vol 467-469 ◽  
pp. 1546-1549
Author(s):  
Rong Hua Qiu ◽  
Guang Shen Xu
Keyword(s):  
High Resolution ◽  
High Dimension ◽  
Distinct Difference ◽  
Positioning System ◽  
Positioning Accuracy ◽  
System Error ◽  
Translation Stage

The motion precision of the translation stage in high-resolution Stereolithography System is the basic for RP system to fabricate object with high dimension accuracy. The motion precision of the translation stage in high-resolution Stereolithography System was investigated and estimated, and the experiments results indicate that the unidirectional accuracy of positioning in Z direction is 6.4µm, and the unidirectional repeatability of positioning of the translation stage in Z direction is 6.4µm. The motion precision of the translation stage can satisfy the requirements of high-resolution SL system. The phenomena that the unidirectional positioning system error and the unidirectional repeatability positioning accuracy have distinct difference was researched, and it is fund that different load status of the translation stage is the main reason during the translation stage moving up and down.

Dynamic and Positioning Performances of Linear Electromechanical Actuator

2015 ◽  
Vol 809-810 ◽  
pp. 682-687
Author(s):  
Vasile Nasui ◽  
Mihai Banica ◽  
Dinu Darabă
Keyword(s):  
Dynamic Characteristics ◽  
Practical Importance ◽  
Correct Identification ◽  
Positioning System ◽  
Positioning Error ◽  
Servo Motor ◽  
Positioning Accuracy ◽  
Electromechanical Actuator ◽  
Initial Errors ◽  
Selection For

This paper presents the dynamic characteristics and the proposed positioning performance of the system to them investigated experimentally. In this research, we developed the positioning system and we evaluated positioning accuracy. The developed system uses a servo motor for motion actuation. In this paper, we focused on studying the dependency of the positioning error – elementary errors – the position of the conducting element for the mechanism of the transformation of the rotation translation movement, representatively the mechanism screw – screwdriver and on emphasizing the practical consequences in the field of design, regulation and exploitation of the correct identification of all the initial errors in the structure of the mechanism, their character and the selection for an ultimate calculus of these which are of a real practical importance.

scholarly journals Improved Visible Light-Based Indoor Positioning System Using Machine Learning Classification and Regression

2019 ◽  
Vol 9 (6) ◽  
pp. 1048 ◽  
Author(s):  
Huy Tran ◽  
Cheolkeun Ha
Keyword(s):  
Machine Learning ◽  
Visible Light ◽  
Noise Reduction ◽  
Indoor Positioning ◽  
Computational Time ◽  
Dual Function ◽  
Positioning System ◽  
Positioning Accuracy ◽  
Positioning Systems ◽  
Machine Learning Classification

Recently, indoor positioning systems have attracted a great deal of research attention, as they have a variety of applications in the fields of science and industry. In this study, we propose an innovative and easily implemented solution for indoor positioning. The solution is based on an indoor visible light positioning system and dual-function machine learning (ML) algorithms. Our solution increases positioning accuracy under the negative effect of multipath reflections and decreases the computational time for ML algorithms. Initially, we perform a noise reduction process to eliminate low-intensity reflective signals and minimize noise. Then, we divide the floor of the room into two separate areas using the ML classification function. This significantly reduces the computational time and partially improves the positioning accuracy of our system. Finally, the regression function of those ML algorithms is applied to predict the location of the optical receiver. By using extensive computer simulations, we have demonstrated that the execution time required by certain dual-function algorithms to determine indoor positioning is decreased after area division and noise reduction have been applied. In the best case, the proposed solution took 78.26% less time and provided a 52.55% improvement in positioning accuracy.

scholarly journals An Ultra-Short Baseline Underwater Positioning System with Kalman Filtering

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 143
Author(s):  
Qinghua Luo ◽  
Xiaozhen Yan ◽  
Chunyu Ju ◽  
Yunsai Chen ◽  
Zhenhua Luo
Keyword(s):  
Phase Difference ◽  
Kalman Filtering ◽  
Negative Impact ◽  
Minimum Mean Square Error ◽  
Acoustic Signals ◽  
Positioning System ◽  
Short Baseline ◽  
Positioning Accuracy ◽  
Wrong Decision ◽  
Underwater Positioning

The ultra-short baseline underwater positioning is one of the most widely applied methods in underwater positioning and navigation due to its simplicity, efficiency, low cost, and accuracy. However, there exists environmental noise, which has negative impacts on the positioning accuracy during the ultra-short baseline (USBL) positioning process, which results in a large positioning error. The positioning result may lead to wrong decision-making in the latter processing. So, it is necessary to consider the error sources, and take effective measurements to minimize the negative impact of the noise. In our work, we propose a USBL positioning system with Kalman filtering to improve the positioning accuracy. In this system, we first explore a new kind of element array to accurately capture the acoustic signals from the object. We then organically combine the Kalman filters with the array elements to filter the acoustic signals, using the minimum mean-square error rule to obtain accurate acoustic signals. We got the high-precision phase difference information based on the non-equidistant quaternary original array and the phase difference acquisition mechanism. Finally, on account of the obtained accurate phase difference information and position calculation, we determined the coordinates of the underwater target. Comprehensive evaluation results demonstrate that our proposed USBL positioning method based on the Kalman filter algorithm can effectively enhance the positioning accuracy.

scholarly journals Sensorless kinesthetic teaching of robotic manipulators assisted by observer-based force control

2017 ◽  
Author(s):  
Martino Capurso ◽  
M. Mahdi Ghazaei Ardakani ◽  
Rolf Johansson ◽  
Anders Robertsson ◽  
Paolo Rocco
Keyword(s):  
Force Control ◽  
Robotic Manipulators

scholarly journals A New Efficient Stiffness Evaluation Method to Improve Accuracy of Hexapods

2018 ◽  
Author(s):  
Vinayak J. Kalas ◽  
Alain Vissière ◽  
Thierry Roux ◽  
Olivier Company ◽  
Sébastien Krut ◽  
...  
Keyword(s):  
Evaluation Method ◽  
Positioning System ◽  
Positioning Error ◽  
Stiffness Parameter ◽  
Positioning Accuracy ◽  
Stiffness Evaluation ◽  
Improve Accuracy ◽  
Identification Technique ◽  
Six Degree Of Freedom ◽  
Structural Compliance

Structural compliance of hexapods limits their positioning accuracy. Taking a step towards solving this problem, this paper proposes a new efficient method to evaluate the stiffness of hexapods in order to predict and correct their positioning error due to compliance. The proposed method can be used to predict the six degree of freedom deflection of the platform under load. This method uses a simple lumped stiffness parameter model whose parameters can be estimated using the identification technique presented in this paper. An experimental study with micrometer level measurements performed on a hexapod based micro-positioning system is used to assess the efficiency of the presented method.

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