A Novel Method for Roll Error Measurement of a Linear Worktable of a Machine Tool

2011 ◽  
Vol 697-698 ◽  
pp. 301-304
Author(s):  
L. Han ◽  
Da Wei Zhang ◽  
Liang Yu Cui

This paper proposes a multi-step and multi-probe method to measure the roll error of a linear worktable during its movement. Two displacement sensors are used and two measurement steps are employed. Compared with two displacement sensors and a sensing target with high flatness method or a method using autocollimator, this method is in low cost and easier to be carried out. In proposed system, the slope information of roll error is obtained by sensor fusion technology. Roll error estimation algorithm is derived, and sequential-two-point method is used to sample sensors’ signal. Simulation and experimental results show the feasibility of the proposed method.

2013 ◽  
Vol 284-287 ◽  
pp. 1723-1728
Author(s):  
Shih Ming Wang ◽  
Han Jen Yu ◽  
Hung Wei Liao

Error compensation is an effective and inexpensive way that can further enhance the machining accuracy of a multi-axis machine tool. The volumetric error measurement method is an essential of the error compensation method. The measurement of volumetric errors of a 5-axis machine tool is very difficult to be conducted due to its complexity. In this study, a volumetric-error measurement method using telescoping ball-bar was developed for the three major types of 5-axis machines. With the use of the three derived error models and the two-step measurement procedures, the method can quickly determine the volumetric errors of the three types of 5-axis machine tools. Comparing to the measurement methods currently used in industry, the proposed method provides the advantages of low cost, easy setup, and high efficiency.


Robotica ◽  
2021 ◽  
pp. 1-18
Author(s):  
Majid Yekkehfallah ◽  
Ming Yang ◽  
Zhiao Cai ◽  
Liang Li ◽  
Chuanxiang Wang

SUMMARY Localization based on visual natural landmarks is one of the state-of-the-art localization methods for automated vehicles that is, however, limited in fast motion and low-texture environments, which can lead to failure. This paper proposes an approach to solve these limitations with an extended Kalman filter (EKF) based on a state estimation algorithm that fuses information from a low-cost MEMS Inertial Measurement Unit and a Time-of-Flight camera. We demonstrate our results in an indoor environment. We show that the proposed approach does not require any global reflective landmark for localization and is fast, accurate, and easy to use with mobile robots.


Author(s):  
A. Hendaoui ◽  
D. Vrel ◽  
A. Amara ◽  
P. Langlois ◽  
M. Guérioune
Keyword(s):  
Low Cost ◽  

2014 ◽  
Vol 607 ◽  
pp. 791-794 ◽  
Author(s):  
Wei Kang Tey ◽  
Che Fai Yeong ◽  
Yip Loon Seow ◽  
Eileen Lee Ming Su ◽  
Swee Ho Tang

Omnidirectional mobile robot has gained popularity among researchers. However, omnidirectional mobile robot is rarely been applied in industry field especially in the factory which is relatively more dynamic than normal research setting condition. Hence, it is very important to have a stable yet reliable feedback system to allow a more efficient and better performance controller on the robot. In order to ensure the reliability of the robot, many of the researchers use high cost solution in the feedback of the robot. For example, there are researchers use global camera as feedback. This solution has increases the cost of the robot setup fee to a relatively high amount. The setup system is also hard to modify and lack of flexibility. In this paper, a novel sensor fusion technique is proposed and the result is discussed.


2015 ◽  
Vol 2015 ◽  
pp. 1-18 ◽  
Author(s):  
Heikki Hyyti ◽  
Arto Visala

An attitude estimation algorithm is developed using an adaptive extended Kalman filter for low-cost microelectromechanical-system (MEMS) triaxial accelerometers and gyroscopes, that is, inertial measurement units (IMUs). Although these MEMS sensors are relatively cheap, they give more inaccurate measurements than conventional high-quality gyroscopes and accelerometers. To be able to use these low-cost MEMS sensors with precision in all situations, a novel attitude estimation algorithm is proposed for fusing triaxial gyroscope and accelerometer measurements. An extended Kalman filter is implemented to estimate attitude in direction cosine matrix (DCM) formation and to calibrate gyroscope biases online. We use a variable measurement covariance for acceleration measurements to ensure robustness against temporary nongravitational accelerations, which usually induce errors when estimating attitude with ordinary algorithms. The proposed algorithm enables accurate gyroscope online calibration by using only a triaxial gyroscope and accelerometer. It outperforms comparable state-of-the-art algorithms in those cases when there are either biases in the gyroscope measurements or large temporary nongravitational accelerations present. A low-cost, temperature-based calibration method is also discussed for initially calibrating gyroscope and acceleration sensors. An open source implementation of the algorithm is also available.


2007 ◽  
Vol 121-123 ◽  
pp. 611-614
Author(s):  
Che Hsin Lin ◽  
Jen Taie Shiea ◽  
Yen Lieng Lin

This paper proposes a novel method to on-chip fabricate a none-dead-volume microtip for ESI-MS applications. The microfluidic chip and ESI tip are fabricated in low-cost plastic based materials using a simple and rapid fabrication process. A constant-speed-pulling method is developed to fabricate the ESI tip by pulling mixed PMMA glue using a 30-μm stainless wire through the pre-formed microfluidic channel. The equilibrium of surface tension of PMMA glue will result in a sharp tip after curing. A highly uniform micro-tip can be formed directly at the outlet of the microfluidic channel with minimum dead-volume zone. Detection of caffeine, myoglobin, lysozyme and cytochrome C biosamples confirms the microchip device can be used for high resolution ESI-MS applications.


Author(s):  
Shih-Ming Wang ◽  
Chih-Peng Yang ◽  
Zhe-Zhi Ye ◽  
Chuntai Yen

The products of 3C, bioscience, medical industry, and aerospace industry are becoming smaller and smaller. The components of the products are made of various materials with complex 3D shapes requiring high accuracy in their dimensions and contours. An accurate micro-/meso-scale CNC machine tool is an essential part of this technology. A new type of CNC micro machine tool with a toggle-like mechanism having the characteristics of low-cost and fine-resolution was developed. With geometric reduction principle, the machine can provide finer feed resolution and better positioning accuracy without using high-end driving components and controller. The kinematics model and characteristics of the machine were derived and analyzed. Modal analysis and dynamic compliance analysis were employed to design a light-weight structure with good stiffness. The accuracy calibration results showed the machine can reach a positioning accuracy of 500 nm. Prototype of the machine was built, and furthermore some micro machining examples were demonstrated in this paper.


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