scholarly journals Functional Design of a 6-DOF Platform for Micro-Positioning

Robotics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 99
Author(s):  
Matteo-Claudio Palpacelli ◽  
Luca Carbonari ◽  
Giacomo Palmieri ◽  
Fabio D’Anca ◽  
Ettore Landini ◽  
...  
Keyword(s):  
Kinematic Model ◽  
High Accuracy ◽  
Functional Design ◽  
Spatial Motion ◽  
Precise Positioning ◽  
Singular Configurations ◽  
Physical Prototype ◽  
Parallel Kinematic ◽  
Parallel Platform ◽  
Accuracy And Repeatability

Parallel kinematic machines (PKMs) have demonstrated their potential in many applications when high stiffness and accuracy are needed, even at micro- and nanoscales. The present paper is focused on the functional design of a parallel platform providing high accuracy and repeatability in full spatial motion. The hexaglide architecture with 6-PSS kinematics was demonstrated as the best solution according to the specifications provided by an important Italian company active in the field of micro-positioning, particularly in vacuum applications. All the steps needed to prove the applicability of such kinematics at the microscale and their inherent advantages are presented. First, the kinematic model of the manipulator based on the study’s parametrization is provided. A global conditioning index (GCI) is proposed in order to optimize the kinetostatic performance of the robot, so that precise positioning in the required platform workspace is guaranteed avoiding singular configurations. Some numerical simulations demonstrate the effectiveness of the study. Finally, some details about the realization of a physical prototype are given.

scholarly journals Modelling, Design and Validation of a Parallel Kinematic Robot for Additive Manufacture Applications

2021 ◽  
pp. 019-029
Author(s):  
Lahoud Marcel ◽  
Melendez Leonardo ◽  
Gil Arturo
Keyword(s):  
Additive Manufacturing ◽  
Open Source Software ◽  
Design Method ◽  
Kinematic Model ◽  
Additive Manufacture ◽  
Parallel Kinematics ◽  
Cartesian Space ◽  
Parallel Kinematic ◽  
Manufacturing Applications ◽  
Design Construction

The additive manufacture is a fabrication process that has taken huge steps in the last decade, even though the first researches and prototypes are around since almost forty years ago. In this article, a design method for a Parallel Kinematics Robot for Additive Manufacturing Applications is proposed. A numerical model is obtained from the kinematics of the robot for which the design, construction and assembly are planned using recycled materials and equipment. The control of the robot is done using open source software, allowing the planning of trajectories in the Cartesian space on a maximum designed cylindrical workspace of 300mm in diameter by 300mm high. At the end of the work the robot was identified, the kinematic model was validated and considerations for future works were given.

scholarly journals Real Time Trajectory Correction System Of Optical Head In Laser Welding

2015 ◽  
Vol 9 (4) ◽  
pp. 265-269 ◽  
Author(s):  
Wojciech Cieszyński ◽  
Michał Zięba ◽  
Jacek Reiner
Keyword(s):  
Laser Beam ◽  
Laser Welding ◽  
Real Time ◽  
Laser Processing ◽  
High Accuracy ◽  
Precise Positioning ◽  
Optical Head ◽  
Welding Technology ◽  
Trajectory Correction ◽  
Correction System

Abstract Application of laser welding technology requires that the laser beam is guided through the whole length of the joint with sufficiently high accuracy. This paper describes result of research on development of optomechatronic system that allows for the precise positioning of the laser head’s TCP point on the edge of welded elements during laser processing. The developed system allows for compensation of workpiece’s fixture inaccuracies, precast distortions and workpiece deformations occurring during the process.

Complete kinematic calibration of a 6-RRRPRR parallel kinematic machine based on the optimal measurement configurations

2019 ◽  
Vol 234 (1) ◽  
pp. 121-136 ◽  
Author(s):  
Chunyang Han ◽  
Yang Yu ◽  
Zhenbang Xu ◽  
Xiaoming Wang ◽  
Peng Yu ◽  
...  
Keyword(s):  
Kinematic Model ◽  
Inverse Kinematic ◽  
Error Model ◽  
Kinematic Calibration ◽  
Universal Joint ◽  
Parallel Kinematic Mechanism ◽  
Simulation And Experiment ◽  
Parallel Kinematic ◽  
Kinematic Mechanism ◽  
Selection Of

This paper presents a kinematic calibration of a 6-RRRPRR parallel kinematic mechanism with offset RR-joints that would be applied in space positioning field. In order to ensure highly accurate and highly effective calibration process, the complete error model, which contains offset universal joint errors, is established by differentiating inverse kinematic model. A calibration simulation comparison with non-complete error model shows that offset universal joint errors are crucial to improve the calibration accuracy. Using the error model, an optimal calibration configuration selection algorithm is developed to determine the least number of measurement configurations as well as the optimal selection of these configurations from the feasible configuration set. To verify the effectiveness of kinematic calibration, a simulation and experiment were performed. The results show that the developed approach can effectively improve accuracy of a parallel kinematic mechanism with relatively low number of calibration configurations.

scholarly journals A Novel Three-SPR Parallel Platform for Vessel Wave Compensation

2020 ◽  
Vol 8 (12) ◽  
pp. 1013
Author(s):  
Yong Zhan ◽  
Huichun Tian ◽  
Jianan Xu ◽  
Shaofei Wu ◽  
Junsheng Fu
Keyword(s):  
Compensation Effect ◽  
Kinematic Model ◽  
Inverse Kinematic ◽  
Ship Motion ◽  
Forward Kinematics ◽  
Positioning System ◽  
Sea State ◽  
Dynamic Positioning System ◽  
Upper Deck ◽  
Parallel Platform

A wave compensation platform based on 3-SPR parallel platform is designed for marine ships with a dynamic positioning system. It can compensate for the heave, rolling, and pitching movement of a vessel under level 4 sea state. The forward kinematics of the mechanism is used to draw the central point position workspace and the attitude workspace of the moving deck of the compensation platform. The compensation effects of the 3-RPS parallel compensation platform and the 3-SPR parallel compensation platform are compared, and the feasibility and superiority of the compensation scheme using the 3-SPR parallel compensation platform are proved. To lower the working height of the upper deck of the compensation platform and reduce the extension range of the support legs, the structure of the compensation platform is optimized, and a novel 3-SPR parallel platform is designed. Finally, a simulation model was established. Using the inverse kinematic model as a compensation movement solver which can online calculate the length of branch legs based on the measured heaving, rolling, and pitching values of vessels, the compensation effect of the new structure under a certain sea state is simulated. The result demonstrated the efficiency of the ship motion decoupling movement of the newly designed compensation platform and proved the competence of it.

Development of fully automated quantitative capillary electrophoresis with high accuracy and repeatability

2015 ◽  
Vol 30 (3) ◽  
pp. 390-395 ◽  
Author(s):  
Yuan Xu ◽  
Bang-zan Ling ◽  
Wen-jun Zhu ◽  
Dong Yao ◽  
Lin Zhang ◽  
...  
Keyword(s):  
Capillary Electrophoresis ◽  
High Accuracy ◽  
Accuracy And Repeatability

scholarly journals Analysis of Three Different Kalman Filter Implementations for Agricultural Vehicle Positioning

2009 ◽  
Vol 3 (1) ◽  
pp. 13-19 ◽  
Author(s):  
M. Rodríguez ◽  
J. Gómez
Keyword(s):  
Kalman Filter ◽  
Kinematic Model ◽  
High Accuracy ◽  
Vehicle Model ◽  
Gps Receivers ◽  
Autonomous Guidance ◽  
Agricultural Vehicle ◽  
Vehicle Positioning ◽  
The Cost ◽  
Very High

Conventional positioning techniques based on GPS receivers are not accurate enough to be used with autonomous guidance systems. High accuracy GPS receivers can be employed, but the cost of the system would be very high. The alternative solution presented in this article is to combine the data provided by different positioning sensors using a Kalman filter. The described procedure also uses an odometric estimation of the mobile position, based on the kinematic model of the agricultural vehicle. Three different implementations of the Kalman filter are described, using different sensor combinations but based on the same vehicle model.

scholarly journals Structural Parameters and Working Range Estimation of Excavator Backhoe Mechanism

2019 ◽  
Vol 8 (2S10) ◽  
pp. 867-872
Keyword(s):  
Structural Parameters ◽  
Kinematic Model ◽  
Computer Algorithm ◽  
Joint Angles ◽  
Range Estimation ◽  
Kinematical Model ◽  
Physical Prototype ◽  
Solid Foundation ◽  
Forward Kinematic ◽  
Earthmoving Machines

Earthmoving machines like excavators and loaders characteristics such as productivity, weight, reliability depend on their backhoe mechanism. For that, the backhoe mechanism has to deliver the desired working range, digging forces and stability which are dependent on structural parameters like components length and joint angles. This paper describes the method of developing a backhoe mechanism for the desired working range which constitutes cutting heights and reaches by using structural parameters. This requires to develop forward kinematical model by considering the backhoe mechanism as a mechanical manipulator. A computer algorithm was developed, that uses the forward kinematic model, to estimate the working range. Also, a relationship is established between joint angles and cylinder lengths. Results of Virtual prototype, modeled and simulated in MSC ADAMS along with the testing results of BEML designed Physical prototype were used to validate the working range and structural parameters. This research provides a solid foundation for analyzing the effect of structural parameters on digging forces and stability.

scholarly journals Micrometer Positioning Accuracy With a Planar Parallel Continuum Robot

2021 ◽  
Vol 8 ◽  
Author(s):  
Benjamin Mauzé ◽  
Guillaume J. Laurent ◽  
Redwan Dahmouche ◽  
Cédric Clévy
Keyword(s):  
Kinematic Model ◽  
High Accuracy ◽  
Circular Path ◽  
Continuum Robots ◽  
Continuum Robot ◽  
Good Potential ◽  
Proper Estimation ◽  
Articulated Robots ◽  
Automatic Positioning ◽  
Influential Parameters

Parallel Continuum Robots (PCR) have several advantages over classical articulated robots, notably a large workspace, miniaturization capabilities and safe human-robot interactions. However, their low accuracy is still a serious drawback. Indeed, several conditions have to be met for PCR to reach a high accuracy, namely: a repeatable mechanical structure, a correct kinematic model, and a proper estimation of the model’s parameters. In this article, we propose a methodology that allows reaching a micrometer accuracy with a PCR. This approach emphasizes the importance of using a repeatable continuum mechanism, identifying the most influential parameters of an accurate kinematic model of the robot and precisely measuring them. The experimental results show that the proposed approach allows to reach an accuracy of 3.3 µm in position and 0.5 mrad in orientation over a 10 mm long circular path. These results push the current limits of PCR accuracy and make them good potential candidates for high accuracy automatic positioning tasks.

Study on a 4-DOF multi-dimensional vibration isolation platform based on 4-UPU parallel mechanism

2021 ◽  
Author(s):  
Ying Zhang ◽  
Xiaodong Guo ◽  
Shijia Yu
Keyword(s):  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Vibration Isolation ◽  
Kinematic Model ◽  
Experimental Studies ◽  
Optimization Method ◽  
Response Analysis ◽  
Vibration Model ◽  
Fixed Base ◽  
Physical Prototype

A novel 4-DOF (degrees of freedom) multi-dimensional vibration isolation platform (MDVIP) based on 4-UPU (U denotes universal joint, P denotes prismatic joint) parallel mechanism is put forward for vibration isolation of the sensitive devices. It consists of 4 limbs and each limb has two universal joints and a module of spring damper. The kinematic model and vibration model of the proposed MDVIP are established and analyzed. The main dimensions of the MDVIP and the parameters of the spring damper module are designed by optimization method to meet various design requirements and constraints. Both the virtual prototype and physical prototype of the MDVIP are built to testify the vibration isolation performance. The results of numerical calculation, simulation and experimental studies based on vibration response analysis show that the proposed MDVIP can isolate at least 78% vibration from the fixed base in three axial directions and 64% vibration in the direction around the Z-axis, and thus may attenuate the disturbances to the items on the moving platform to a large extent.

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