Kinematic Errors on a C-Type Gear with a Parabolic Surface

2018 ◽  
Vol 46 (6) ◽  
pp. 20170318
Author(s):  
Hsueh-Cheng Yang ◽  
Ching-Sheng Chang
Keyword(s):  
Parabolic Surface ◽  
Kinematic Errors

A flow behavior of Sutterby nanofluid near the catalytic parabolic surface

2022 ◽  
Vol 131 ◽  
pp. 105821
Author(s):  
T. Salahuddin ◽  
Z. Ali ◽  
Muhammad Awais ◽  
Mair Khan ◽  
Mohamed Altanji
Keyword(s):  
Flow Behavior ◽  
Parabolic Surface

A Novel Error Equivalence Model on the Kinematic Error of the Linear Axis of High-End Machine Tool

2021 ◽  
Author(s):  
Xinxin LI ◽  
Zhi-Min Li ◽  
Sun Jin ◽  
Jichang Zhang ◽  
Siyi Ding ◽  
...  
Keyword(s):  
Machine Tool ◽  
Elastic Deformation ◽  
Numerical Control ◽  
Small Displacement ◽  
Kinematic Error ◽  
Guide Rail ◽  
Linear Guide ◽  
Proposed Model ◽  
Equivalence Model ◽  
Kinematic Errors

Abstract The kinematic errors of the linear axis play a key role in machining precision of high-end CNC (Computer Numerical Control) machine tool. The quantification of error relationship is still an urgent problem to be solved in the assembly process of the linear axis, especially considering the effect of the elastic deformation of rollers. A systematic error equivalence model of slider is proposed to improve the prediction accuracy for kinematic errors of the linear axis which contains the base, the linear guide rail and carriage. Firstly, the geometric errors of assembly surface of linear guide rail are represented by small displacement torsor. According to the theory of different motion of robots, the error equivalence model of a single slider is established, namely the geometric error of assembly surface of linear guide rail and the pose error of slider is equivalent to the elastic deformation of roller. Based on the principle of vector summation, the kinematic error of a single slider is mapped to the carriage and the kinematic error of the linear axis is obtained. Besides, experiments validation of kinematic error model of the linear axis is carried out. It is indicated that the proposed model is accurate and feasible. The proposed model can provide an accurate guidance for the manufacturing and operation performance of the linear axis in quantification, and a more effective reference for the engineers at the design and assembly stage.

Simultaneous base and tool calibration for self-calibrated parallel robots

Robotica ◽  
2002 ◽  
Vol 20 (4) ◽  
pp. 367-374 ◽  
Author(s):  
Guilin Yang ◽  
I-Ming Chen ◽  
Song Huat Yeo ◽  
Wee Kiat Lim
Keyword(s):  
Parallel Robot ◽  
Parallel Robots ◽  
Sufficient Accuracy ◽  
Least Square ◽  
Mobile Platform ◽  
Calibration Model ◽  
End Effector ◽  
The World ◽  
Kinematic Transformation ◽  
Kinematic Errors

In this paper, we focus on the base and tool calibration of a self-calibrated parallel robot. After the self-calibration of a parellel robot by using the built-in sensors in the passive joints, its kinematic transformation from the robot base to the mobile platform frame can be computed with sufficient accuracy. The base and tool calibration, hence, is to identify the kinematic errors in the fixed transformations from the world frame to the robot base frame and from the mobile platform frame to the tool (end-effector) frame in order to improve the absolute positioning accuracy of the robot. Using the mathematical tools from group theory and differential geometry, a simultaneous base and tool calibration model is formulated. Since the kinematic errors in a kinematic transformation can be represented by a twist, i.e. an element of se(3), the resultant calibration model is simple, explicit and geometrically meaningful. A least-square algorithm is employed to iteratively identify the error parameters. The simulation example shows that all the preset kinematic errors can be fully recovered within three to four iterations.

scholarly journals Image-based Visual Servoing for Optimal Grasping

2001 ◽  
Vol 13 (5) ◽  
pp. 479-487
Author(s):  
Hideo Fujimoto ◽  
◽  
Liu-Cun Zhu ◽  
Karim Abdel-Malek ◽  
Keyword(s):  
Visual Servoing ◽  
Ccd Camera ◽  
Servo Control ◽  
Visually Guided ◽  
Grasp Planning ◽  
Vector Processing ◽  
Vector Error ◽  
Proposed Model ◽  
Control Scheme ◽  
Kinematic Errors

One of the most common tasks in robotics is grasping. Although the formulation of optimal grasping has been addressed using a variety of approaches, there are only a few grasping systems that can operate in uncertain dynamic environments. In this paper, we present an image-based visual servoing method and system for optimal object grasping by introducing the method of visual vectors. A CCD camera mounted on a robot end-effector constructs the visually guided servo control system and the control scheme lends itself to task-level specification of manipulation goals. The proposed approach integrates vision, grasp planning, and vision=guided control to accomplish the optimal grasping task. The grasping task is to control the robot so the vectors of the end-effector's landmark (e.g., finger vector) and a target object's grasp coincide. These vectors can be used to perform the work of a stable grasping of an object that is presented in an unstructured manner. Visual vectors in image frame are obtained by analyzing the object's image and projection. Our objective in implementing vector processing is to estimate the vector error between the finger and grasp vectors, and to control the robot to eliminate kinematic errors. The proposed model is illustrated through examples and its effectiveness is validated using computer simulation.

Error estimation and sensitivity analysis of the 3-UPU translational parallel robot due to design parameter uncertainties

2018 ◽  
Vol 233 (8) ◽  
pp. 2713-2727 ◽  
Author(s):  
S El Hraiech ◽  
AH Chebbi ◽  
Z Affi ◽  
L Romdhane
Keyword(s):  
Sensitivity Analysis ◽  
Vertical Axis ◽  
Parallel Robot ◽  
Design Parameters ◽  
Analysis Method ◽  
Parameter Uncertainties ◽  
End Effector ◽  
Interval Analysis Method ◽  
Influential Parameters ◽  
Kinematic Errors

This work deals with the estimation and the sensitivity analysis of the 3-UPU parallel robot error. Based on the Newton–Euler formalism, the robot dynamic model is given in a closed form. This model is validated by the software ADAMS. Using the interval analysis method, a new algorithm is proposed, which estimates the errors in the motion of the end-effector and the errors in the actuator forces as a function of the design parameters uncertainties. The obtained results show that the kinematic errors are minimal at the workspace center. Moreover, these errors increase as the platform moves along the vertical axis. It is also shown that kinematic errors in the actuator joints are the most influential parameters on the manipulator accuracy. Therefore, using actuators with a higher accuracy can highly reduce the errors in motion of the platform.

Kinematical Optimization of Spiral Bevel Gears

1992 ◽  
Author(s):  
Zhang-Hua Fong ◽  
Chung-Biau Tsay
Keyword(s):  
Mathematical Model ◽  
Bevel Gear ◽  
Tooth Surface ◽  
Spiral Bevel Gear ◽  
Tooth Contact ◽  
Spiral Bevel Gears ◽  
Bevel Gears ◽  
Contact Patterns ◽  
Spiral Bevel ◽  
Kinematic Errors

Abstract Kinematical optimization and sensitivity analysis of circular-cut spiral bevel gears are investigated in this paper. Based on the Gleason spiral bevel gear generator and EPG test machine, a mathematical model is proposed to simulate the tooth contact conditions of the spiral bevel gear set. All the machine settings and assembly data are simulated by simplified parameters. The tooth contact patterns and kinematic errors are obtained by the proposed mathematical model and the tooth contact analysis techniques. Loaded tooth contact patterns are obtained by the differential geometry and the Hertz contact formulas. Tooth surface sensitivity due to the variation of machine settings is studied. The corrective machine settings can be calculated by the sensitive matrix and the linear regression method. An optimization algorithm is also developed to minimize the kinematic errors and the discontinuity of tooth meshing. According to the proposed studies, an improved procedure for development of spiral bevel gears is suggested. The results of this paper can be applied to determine the sensitivity and precision requirements in manufacturing, and improve the running quality of the spiral bevel gears. Two examples are presented to demonstrate the applications of the optimization model.

A Systematic Approach to Model Arbitrary Non Geometric Kinematic Errors

1994 ◽  
pp. 129-138 ◽  
Author(s):  
M. Vincze ◽  
K. M. Filz ◽  
H. Gander ◽  
J. P. Prenninger ◽  
G. Zeichen
Keyword(s):  
Systematic Approach ◽  
Kinematic Errors
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