Velocity and acceleration estimation for optical incremental encoders

Merry, Rje Roel; Molengraft, van de Mjg René; Steinbuch, M Maarten

doi:10.1016/j.mechatronics.2009.06.010

Cited by 94 publications

(46 citation statements)

References 9 publications

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“…To reduce noise in differentiation, a time stamping method that uses polynomial fit using previous and present positions is applied. 15 In this paper, the first order fitting and five time stamps are used.…”

Section: B Developed Printed Grating Scale Encodermentioning

confidence: 99%

Direct and precise measurement of displacement and velocity of flexible web in roll-to-roll manufacturing systems

Kang

Kim

Lee

et al. 2013

Review of Scientific Instruments

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Interest in the production of printed electronics using a roll-to-roll system has gradually increased due to its low mass-production costs and compatibility with flexible substrate. To improve the accuracy of roll-to-roll manufacturing systems, the movement of the web needs to be measured precisely in advance. In this paper, a novel measurement method is developed to measure the displacement and velocity of the web precisely and directly. The proposed algorithm is based on the traditional single field encoder principle, and the scale grating has been replaced with a printed grating on the web. Because a printed grating cannot be as accurate as a scale grating in a traditional encoder, there will inevitably be variations in pitch and line-width, and the motion of the web should be measured even though there are variations in pitch and line-width in the printed grating patterns. For this reason, the developed algorithm includes a precise method of estimating the variations in pitch. In addtion, a method of correcting the Lissajous curve is presented for precision phase interpolation to improve measurement accuracy by correcting Lissajous circle to unit circle. The performance of the developed method is evaluated by simulation and experiment. In the experiment, the displacement error was less than 2.5 μm and the velocity error of 1σ was about 0.25%, while the grating scale moved 30 mm.

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Section: B Developed Printed Grating Scale Encodermentioning

confidence: 99%

Direct and precise measurement of displacement and velocity of flexible web in roll-to-roll manufacturing systems

Kang

Kim

Lee

et al. 2013

Review of Scientific Instruments

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“…To improve the measurement accuracy of incremental optical encoder especially at low speed, speed estimation methods are developed which can get the instantaneous speed at the sampling time even at very low speed. [1][2] In the past years, many researches and papers offered sensorless speed estimation methods, such as model reference adaptive system, nonlinear observer, high frequency signal injection, EKF, sliding-mode observer [3][4][5][6][7][8][9] etc. Most of these speed estimation algorithms are based on the motor voltage model and are normally complex and heavily dependent on motor parameters.…”

Section: Introductionmentioning

confidence: 99%

Speed and load torque estimation of SPMSM based on Kalman filter

Wang

2015

2015 IEEE International Conference on Mechatronics and Automation (ICMA)

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This paper presents a kalman filter algorithm for speed estimation of surface permanent magnet synchronous motor (SPMSM) with load torque estimation at the same time based on the mechanical kinemic equations of the motor. Unlike sensorless control, this approach is an optimal information fusion of the optical encoder speed measurement and kinemic model based speed estimation on sense of minimum mean square error. Further more it requires less motor parameters than common sensorless EKF speed estimation. Simulation results show that the novel method can achieve high estimation precision and consistency errors over the entire speed range. Load torque estimation at the same time ensures the robustness with the torque interference.Index Terms -kalman filter, SPMSM, speed estimation, Load torque estimation..

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“…Most of these feedback systems are based on optical encoder [2]. Usually, they are attached to servomotors that control the angular position of each joint in the robot [3]. Those sensors provide accurate information about the servomotor position; however, they cannot detect mechanical imperfections and deformations that are common in open chain robots [4].…”

Section: Introductionmentioning

confidence: 99%

Sensor Fusion for Joint Kinematic Estimation in Serial Robots Using Encoder, Accelerometer and Gyroscope

Munoz-Barron

Rivera-Guillen

Osornio-Ríos

et al. 2014

J Intell Robot Syst

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Open-chain manipulator robots play an important role in the industry, since they are utilized in applications requiring precise motion. Highperformance motion of a robot system mainly relies on adequate trajectory planning and the controller that coordinates the movement. The controller performance depends of both, the employed control law and the sensor feedback. Optical encoder feedback is the most used sensor for angular position estimation of each joint in the robot, since they feature accurate and low noise angular position measurements. However, it cannot detect mechanical imperfections and deformations common in open chain robots. Moreover, velocity and acceleration cannot be extracted from the encoder data without adding phase delays. Sensor fusion techniques are found to be a good solution for solving this problem. However, few works has been carried out in serial robots for kinematic estimation of angular position, velocity and acceleration, since the delays induced by the filtering techniques avoids its use as controller feedback. This work proposes a novel sensor-fusion-based feedback system capable of providing complete kinematic information from each joint in 4-degrees of freedom serial robot, with the contribution of a proposed methodology based on Kalman filtering for fusing the information from optical encoder, gyroscope and accelerometer appended to the robot. Calibration and experimentation are carried out for validating the proposal. The results are compared with another kinematic estimation technique finding that this proposal provides more information about the robot movement without adding state delays, which is important for being used as controller feedback.

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Velocity and acceleration estimation for optical incremental encoders

Cited by 94 publications

References 9 publications

Direct and precise measurement of displacement and velocity of flexible web in roll-to-roll manufacturing systems

Direct and precise measurement of displacement and velocity of flexible web in roll-to-roll manufacturing systems

Speed and load torque estimation of SPMSM based on Kalman filter

Sensor Fusion for Joint Kinematic Estimation in Serial Robots Using Encoder, Accelerometer and Gyroscope

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