Analysis of optical linear encoders’ errors under vibration at different mounting conditions

López, Jesús Ramé; Artés, Mariano; Alejandre, I.

doi:10.1016/j.measurement.2011.05.004

Cited by 34 publications

(21 citation statements)

References 12 publications

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“…This case is contemplated in the referenced work [8], providing several LUTs like that depicted in Figure 3 for each one of the possible positions of the encoder in relation to the vibration direction. For the general case where there is no one dominant direction of the excitation, a combination of the values of each one of the LUTs in the different directions is recommended.…”

Section: Methodology For Error Compensationmentioning

confidence: 99%

A New Methodology for Vibration Error Compensation of Optical Encoders

López

Artés

2012

Sensors

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Optical encoders are sensors based on grating interference patterns. Tolerances inherent to the manufacturing process can induce errors in the position accuracy as the measurement signals stand apart from the ideal conditions. In case the encoder is working under vibrations, the oscillating movement of the scanning head is registered by the encoder system as a displacement, introducing an error into the counter to be added up to graduation, system and installation errors. Behavior improvement can be based on different techniques trying to compensate the error from measurement signals processing. In this work a new “ad hoc” methodology is presented to compensate the error of the encoder when is working under the influence of vibration. The methodology is based on fitting techniques to the Lissajous figure of the deteriorated measurement signals and the use of a look up table, giving as a result a compensation procedure in which a higher accuracy of the sensor is obtained.

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Section: Methodology For Error Compensationmentioning

confidence: 99%

A New Methodology for Vibration Error Compensation of Optical Encoders

López

Artés

2012

Sensors

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“…According to the analysis proposed in [16,17], the geometric error of the measurement system refers to the manufacturing error of each component and the assembly error between the components. Figure 1b and Figure 2 show that the errors caused by the installation process in the x -axis and oyz plane are sensitive sources of measurement error.…”

Section: Measurement Model Of Angle Encoder On Tcmsmentioning

confidence: 99%

A New Error Model and Compensation Strategy of Angle Encoder in Torsional Characteristic Measurement System

Chen

Peng

Huang

2019

Sensors

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For systems of measurement, geometric errors such as manufacturing and assembly errors could have a significant impact on the accuracy of the angle encoders of the system. In this study, an error model of angular measurement with geometric errors of a torsional characteristic measurement system was developed based on multibody system theory, the aim of which was to reveal the impact of geometric errors on angular measurement and to compensate the measurement error. According to the principle of spatial error transfer, the decomposition of geometric errors is illustrated and the error matrix of geometric errors is constructed by the Denavit–Hartenberg (DH) method. Subsequently, an error compensation function can be obtained and the impact of geometric error on angular measurement is discussed. Finally, we demonstrate by the experimental results of an ultra-autocollimator that the proposed error compensation method reduced the angular measurement error from 3.7% to 0.7%, which shows that the proposed error model can effectively predict the angular measurement error. In addition, it can be seen from the measurement results of the RV reducer that the error of the torsional characteristic measurement system decreased significantly.

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“…The quality of the electrical signals highly depends on various aspects, like the optical-scanning principle, the design of a reading head and its ability to handle various deformations [32], mechanical vibrations [33][34][35], or temperature variations [36,37]. In order to improve signal quality and to make encoders more robust, manufacturers use advanced optical-scanning methods such as the single-field or interferential scanning principle [38,39], or they implement special-configuration multiple-track analyzer grating to eliminate higher-order harmonic signals [40].…”

Section: Introductionmentioning

confidence: 99%

Experimental Investigation of Linear Encoder’s Subdivisional Errors under Different Scanning Speeds

2020

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Optical encoders are widely used in applications requiring precise displacement measurement and fluent motion control. To reach high positioning accuracy and repeatability, and to create a more stable speed-control loop, essential attention must be directed to the subdivisional error (SDE) of the used encoder. This error influences the interpolation process and restricts the ability to achieve a high resolution. The SDE could be caused by various factors, such as the particular design of the reading head and the optical scanning principle, quality of the measuring scale, any kind of relative orientation changes between the optical components caused by mechanical vibrations or deformations, or scanning speed. If the distorted analog signals are not corrected before interpolation, it is very important to know the limitations of the used encoder. The methodology described in this paper could be used to determine the magnitude of an SDE and its trend. This method is based on a constant-speed test and does not require high-accuracy reference. The performed experimental investigation of the standard optical linear encoder SDE under different scanning speeds revealed the linear relationship between the tested encoder’s traversing velocity and the error value. A more detailed investigation of the obtained results was done on the basis of fast Fourier transformation (FFT) to understand the physical nature of the SDE, and to consider how to improve the performance of the encoder.

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Analysis of optical linear encoders’ errors under vibration at different mounting conditions

Cited by 34 publications

References 12 publications

A New Methodology for Vibration Error Compensation of Optical Encoders

A New Methodology for Vibration Error Compensation of Optical Encoders

A New Error Model and Compensation Strategy of Angle Encoder in Torsional Characteristic Measurement System

Experimental Investigation of Linear Encoder’s Subdivisional Errors under Different Scanning Speeds

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