scholarly journals A Coarse Interval Linearity-Calibration Method Involving Self-Inspection Technique for Displacement Sensors.

1997 ◽  
Vol 63 (5) ◽  
pp. 684-688
Author(s):  
Shinji KASEI ◽  
Yoshimasa TAKIGAMI ◽  
Hirohito MATSITOKA ◽  
Ei IGARASHI
Keyword(s):  
Calibration Method ◽  
Displacement Sensors ◽  
Linearity Calibration

scholarly journals High-Accuracy Calibration Based on Linearity Adjustment for Eddy Current Displacement Sensor

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2842 ◽  
Author(s):  
Wei Liu ◽  
Bing Liang ◽  
Zhenyuan Jia ◽  
Di Feng ◽  
Xintong Jiang ◽  
...  
Keyword(s):  
Eddy Current ◽  
Measurement Accuracy ◽  
Characteristic Curve ◽  
Calibration Method ◽  
High Accuracy ◽  
Output Characteristic ◽  
Displacement Sensor ◽  
Support Vector ◽  
Displacement Sensors ◽  
Calibration Accuracy

High precision position control is essential in the process of parts manufacturing and assembling, where eddy current displacement sensors (ECDSs) are widely used owing to the advantages of non-contact sensing, compact volume, and resistance to harsh conditions. To solve the nonlinear characteristics of the sensors, a high-accuracy calibration method based on linearity adjustment is proposed for ECDSs in this paper, which markedly improves the calibration accuracy and then the measurement accuracy. After matching the displacement value and the output voltage of the sensors, firstly, the sensitivity is adjusted according to the specified output range. Then, the weighted support vector adjustment models with the optimal weight of the zero-scale, mid-scale and full-scale are established respectively to cyclically adjust the linearity of the output characteristic curve. Finally, the final linearity adjustment model is obtained, and both the calibration accuracy and precision are verified by the established calibration system. Experimental results show that the linearity of the output characteristic curve of ECDS adjusted by the calibration method reaches over 99.9%, increasing by 1.9–5.0% more than the one of the original. In addition, the measurement accuracy improves from 11–25 μ m to 1–10 μ m in the range of 6mm, which provides a reliable guarantee for high accuracy displacement measurement.

scholarly journals A Normal Sensor Calibration Method Based on an Extended Kalman Filter for Robotic Drilling

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3485 ◽  
Author(s):  
Dongdong Chen ◽  
Peijiang Yuan ◽  
Tianmiao Wang ◽  
Ying Cai ◽  
Haiyang Tang
Keyword(s):  
Kalman Filter ◽  
Laser Beam ◽  
Extended Kalman Filter ◽  
Zero Point ◽  
Calibration Method ◽  
Sensor Calibration ◽  
Beam Direction ◽  
Displacement Sensors ◽  
Robotic Drilling ◽  
Drilling System

To enhance the perpendicularity accuracy in the robotic drilling system, a normal sensor calibration method is proposed to identify the errors of the zero point and laser beam direction of laser displacement sensors simultaneously. The procedure of normal adjustment of the robotic drilling system is introduced firstly. Next the measurement model of the zero point and laser beam direction on a datum plane is constructed based on the principle of the distance measurement for laser displacement sensors. An extended Kalman filter algorithm is used to identify the sensor errors. Then the surface normal measurement and attitude adjustments are presented to ensure that the axis of the drill bit coincides with the normal at drilling point. Finally, simulations are conducted to study the performance of the proposed calibration method and experiments are carried out on a robotic drilling system. The simulation and experimental results show that the perpendicularity of the hole is within 0.2°. They also demonstrate that the proposed calibration method has high accuracy of parameter identification and lays a basis for high-precision perpendicularity accuracy of drilling in the robotic drilling system.

scholarly journals A flexible calibration method for laser displacement sensors based on a stereo-target

2014 ◽  
Vol 25 (10) ◽  
pp. 105103 ◽  
Author(s):  
Jie Zhang ◽  
Junhua Sun ◽  
Zhen Liu ◽  
Guangjun Zhang
Keyword(s):  
Calibration Method ◽  
Displacement Sensors

Square Layout Four-Point Method for Two-Dimensional Profile Measurement and Self-Calibration Method of Zero-Adjustment Error

2018 ◽  
Vol 12 (5) ◽  
pp. 707-713 ◽  
Author(s):  
Hiroki Shimizu ◽  
◽  
Ryousuke Yamashita ◽  
Takuya Hashiguchi ◽  
Tasuku Miyata ◽  
...  
Keyword(s):  
Calibration Method ◽  
Recurrence Equation ◽  
Profile Measurement ◽  
Two Dimensional ◽  
Measuring Point ◽  
Self Calibration ◽  
Displacement Sensors ◽  
Adjustment Error ◽  
Scan Line ◽  
Height Data

An on-machine measurement method, called the square-layout four-point (SLFP) method with angle compensation, for evaluating two-dimensional (2-D) profiles of flat machined surfaces is proposed. In this method, four displacement sensors are arranged in a square and mounted to the scanning table of a 2-D stage. For measuring the 2-D profile of a target plane, height data corresponding to all measuring points are acquired by means of the raster scanning motion. At the same time, pitching data of the first primary scan line and rolling data of the first subsidiary scan line are monitored by means of two auto-collimators to compensate for major profile errors that arise out of the posture error. Use of the SLFP method facilitates connection of the results of straightness-measurements results obtained for each scanning line by using two additional sensors and rolling data of the first subsidiary scan line. Specifically, the height of a measuring point is calculated by means of a recurrence equation using three predetermined height data for adjacent points in conjunction with data acquired by the four displacement sensors. Results of the numerical simulation performed in this study demonstrate higher efficiency of the SLFP method with angle compensation. During actual measurement, however, it is difficult to perfectly align inline the origin height of each displacement sensor. With regard to the SLFP method, zero-adjustment error is defined as the relative height of a sensor’s origin with respect to the plane comprising origins of the other three sensors. This error accumulates in proportion to number of times the recurrence equation is applied. Simulation results containing the zero-adjustment error demonstrate that accumulation of the said error results in unignorable distortion of measurement results. Therefore, a new self-calibration method for the zero-adjustment error has been proposed. During 2-D profile measurement, two different calculation paths – the raster scan path and orthogonal path – can be used to determine the height of a measurement point. Although heights determined through use of the two paths must ideally be equal, they are observed to be different because accumulated zero-adjustment errors for the two paths are different. In view of this result, the zero-adjustment error can be calculated backwards and calibrated. Validity of the calibration method has been confirmed via simulations and experiments.

scholarly journals A calibration method of robot kinematic parameters by drawstring displacement sensor

2019 ◽  
Vol 16 (5) ◽  
pp. 172988141988307 ◽  
Author(s):  
Yahui Gan ◽  
Jinjun Duan ◽  
Xianzhong Dai
Keyword(s):  
Calibration Method ◽  
Industrial Robots ◽  
Displacement Sensor ◽  
Kinematic Parameters ◽  
Position Measurement ◽  
Positioning Accuracy ◽  
End Effector ◽  
Displacement Sensors ◽  
Absolute Positioning ◽  
The Absolute

Calibration of robot kinematic parameters can effectively improve the absolute positioning accuracy of the end-effector for industrial robots. This article proposes a calibration method for robot kinematic parameters based on the drawstring displacement sensor. Firstly, the kinematic error model for articulated robot is established. Based on such a model, the position measurement system consisting of four drawstring displacement sensors is used to measure the actual position of the robot end-effector. Then, the deviation of the kinematic parameters of the robot is identified by the least-squares method according to robot end-effector deviations. The Cartesian space compensation method is adopted to improve the absolute positioning accuracy of the robot end-effecter. By experiments on the EFORT ER3A robot, the absolute positioning accuracy of the robot is significantly improved after calibration, which shows the effectiveness of the proposed method.

Calibration of Displacement Sensors with High-Precision and Large Measurement Range Using Temporal Speckle Pattern Interferometry

2006 ◽  
Vol 326-328 ◽  
pp. 91-94
Author(s):  
Xi De Li ◽  
Yan Yang
Keyword(s):  
Speckle Pattern ◽  
Calibration Method ◽  
Measurement Range ◽  
Electronic Speckle Pattern Interferometry ◽  
Correlation Property ◽  
Calibration System ◽  
Displacement Sensors ◽  
Time Calibration ◽  
Out Of Plane ◽  
Large Measurement

In the present study, a real-time calibration method for micro displacement sensors is introduced, and a calibration system is developed. SPCM, the sequence pulse counting method previously proposed by us, is capable of automatically determining both the larger range displacement and the performance of a sensor, such as the nonlinear error and the displacement sensitivity within a quarter of the light source wavelength. The new calibration system consists of a programmable motor driven platform, an out-of-plane sensitive electronic speckle pattern interferometry (ESPI), and a sequence image acquisition system. The platform is used to provide displacement changes of a moving component and its displacement is measured by the ESPI and calibrated sensor synchronously. The calibration accuracy of the proposed method is in the submicrometer level and the displacement range can be from sub-micrometer to millimeters depending on the storage capacity of the computer and the correlation property of the interferometer. Three capacitance-type displacement sensors have been calibrated successfully, whose displacement ranges are –300μm to 300μm, –30μm to 30μm, and –3μm to 3μm, respectively.

Model-Based Dynamic Calibration of a Multi-Actuator Gap Leveler for Heavy Plates

2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Robert Brauneis ◽  
Andreas Steinboeck ◽  
Martin Jochum ◽  
Andreas Kugi
Keyword(s):  
Elastic Deformation ◽  
Calibration Method ◽  
Reference Points ◽  
Dynamic Calibration ◽  
Major Drawback ◽  
Displacement Sensors ◽  
Novel Method ◽  
Suitable Reference ◽  
Maintenance Personnel ◽  
Work Rolls

Abstract A novel method to calibrate the work rolls of a precision leveler for heavy plates is proposed. During the leveling process, a sequence of bending steps is imposed on the plate by the work rolls of the leveler to eliminate flatness defects. The respective positions of the rolls define the intensity of the consecutive bends. Any deviation from the desired roll position may result in a suboptimal leveling process. Thus, an exact control of the position of the work rolls is required. Due to backlash, wear, tolerances, and elastic deformation, the roll positions cannot be determined from nominal parameters and dimensions. Therefore, the machine has to be calibrated and properly adjusted to find suitable reference positions for control. During calibration, the structure is prestressed with a suitable test force and the signals of force and displacement sensors are recorded. As a result, reference points for future control inputs are obtained. A major drawback of a frequently used calibration method for levelers is that the work rolls of multi-actuator gap levelers cannot be properly calibrated. In practice, the work rolls are manually adjusted by the maintenance personnel of the machine. In this case, backlash may cause the loaded work rolls to deviate from their intended positions. Thus, a new method to calibrate the position of the individually actuated work rolls is developed and tested.

An absolute calibration method for displacement sensors

Measurement ◽  
2001 ◽  
Vol 29 (1) ◽  
pp. 11-20 ◽  
Author(s):  
Shizhou Zhang ◽  
Satoshi Kiyono
Keyword(s):  
Calibration Method ◽  
Absolute Calibration ◽  
Displacement Sensors

scholarly journals Obtaining characteristics of FMM displacement sensor by applying a flick standard

Mechanik ◽  
2017 ◽  
Vol 90 (11) ◽  
pp. 1041-1043
Author(s):  
Marta Wiśniewska ◽  
Sabina Żebrowska-Łucyk
Keyword(s):  
Calibration Method ◽  
Displacement Sensor ◽  
Characteristic Curves ◽  
Factors Affecting ◽  
The Core ◽  
Displacement Sensors ◽  
Calibration Uncertainty ◽  
Novel Method ◽  
Core Idea

A novel method for obtaining characteristics of displacement sensors applied to form measuring machines is presented. In order to find the characteristic curves of such sensors, flick standards are adopted. In the paper, besides the core idea of this calibration method, there is an influence of some of the most important factors affecting calibration uncertainty presented.

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