Velocity Estimation of Motion Systems Based on Low-Resolution Encoders

2012 ◽  
Vol 135 (1) ◽  
Author(s):  
Hongzhong Zhu ◽  
Toshiharu Sugie
Keyword(s):  
Angular Position ◽  
Velocity Estimation ◽  
Position Sensor ◽  
Low Resolution ◽  
New Approach ◽  
Numerical Examples ◽  
Fitting Method ◽  
Sensor Resolution ◽  
Speed Range ◽  
Incremental Encoder

This paper proposes a new approach to estimate the velocity of mechanical system in the case where the optical incremental encoder is used as the position sensor. First, the actual angular position is reconstructed via moving horizon polynomial fitting method by taking account of quantization feature and the plant dynamics. Then, the reconstruction signal is applied to a classical observer to obtain the velocity estimation. Its robustness against the position sensor resolution and the degree of the polynomial is discussed by some numerical examples. Experiments with very low-resolution encoder in low speed range also confirm its effectiveness.

A High-Precision Absolute Angular Position Sensor With Vernier Capacitive Arrays Based on Time Grating

2019 ◽  
Vol 19 (19) ◽  
pp. 8626-8634 ◽  
Author(s):  
Hongji Pu ◽  
Hewen Wang ◽  
Xiaokang Liu ◽  
Zhicheng Yu ◽  
Kai Peng
Keyword(s):  
High Precision ◽  
Angular Position ◽  
Position Sensor

scholarly journals A New Approach for Analyzing the Reliability of the Repair Facility in a Series System with Vacations

2012 ◽  
Vol 2012 ◽  
pp. 1-16
Author(s):  
Renbin Liu ◽  
Yong Wu
Keyword(s):  
Renewal Process ◽  
Decomposition Method ◽  
Process Theory ◽  
Series System ◽  
New Approach ◽  
Numerical Examples ◽  
Special Cases ◽  
The Mean ◽  
Repair Facility

Based on the renewal process theory we develop a decomposition method to analyze the reliability of the repair facility in ann-unit series system with vacations. Using this approach, we study the unavailability and the mean replacement number during(0,t]of the repair facility. The method proposed in this work is novel and concise, which can make us see clearly the structures of the facility indices of a series system with an unreliable repair facility, two convolution relations. Special cases and numerical examples are given to show the validity of our method.

scholarly journals The Sum and Difference of Two Lognormal Random Variables

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
C. F. Lo
Keyword(s):  
Stochastic Process ◽  
Probability Distributions ◽  
Operator Splitting ◽  
Splitting Method ◽  
Unified Approach ◽  
New Approach ◽  
Numerical Examples ◽  
Operator Splitting Method ◽  
Approximate Probability ◽  
Analytical Series

We have presented a new unified approach to model the dynamics of both the sum and difference of two correlated lognormal stochastic variables. By the Lie-Trotter operator splitting method, both the sum and difference are shown to follow a shifted lognormal stochastic process, and approximate probability distributions are determined in closed form. Illustrative numerical examples are presented to demonstrate the validity and accuracy of these approximate distributions. In terms of the approximate probability distributions, we have also obtained an analytical series expansion of the exact solutions, which can allow us to improve the approximation in a systematic manner. Moreover, we believe that this new approach can be extended to study both (1) the algebraic sum ofNlognormals, and (2) the sum and difference of other correlated stochastic processes, for example, two correlated CEV processes, two correlated CIR processes, and two correlated lognormal processes with mean-reversion.

Fault Tolerant and Nano Displacement Drive Control Method of Photoelectric Motor for Battery Electric Vehicle

2021 ◽  
Vol 16 (2) ◽  
pp. 293-302
Author(s):  
Weiping Liu ◽  
Zhaofeng Wang ◽  
Ximing Zhang ◽  
Yulin Wang ◽  
Bochun Hu ◽  
...  
Keyword(s):  
Electric Vehicle ◽  
Control Method ◽  
Displacement Sensor ◽  
Battery Electric Vehicle ◽  
Position Sensor ◽  
Low Resolution ◽  
Rotor Position ◽  
Displacement Sensors ◽  
Position Signal ◽  
Three Phase

The low-resolution photoelectric position sensor is used, that is, Hall position sensor replaces the traditional photoelectric encoder and other high-resolution position sensors to monitor the rotor position. However, because the three-phase Hall position sensor can only output six position signals, a hardware circuit design of low-resolution position sensor monitoring rotor position signal is proposed. Meanwhile, nanotechnology has been introduced in the study of micro drive of battery electric vehicle (BEV). BEV driver has some disadvantages such as hysteresis, creep and nonlinearity, which seriously affects its application in nano environment. A nano displacement sensor is designed for the characteristics of BEV driver. The nonlinear problem of micro driver is solved through the closed-loop control of position feedback. In the test, through the verification of rotor position and current waveform, it can be proved that the method based on photoelectric position sensor and rotor position signal monitoring can ensure the low deviation of rotor position calculation and correct output signal of three-phase photoelectric position sensor. The decoupling performance of vector control is verified by 3/2 transformation. In the displacement detection of micro driver, the designed nano displacement sensor has higher resolution and its performance is better than that of the previous three generations of displacement sensors.

Using MEMS Accelerometers to Improve Automobile Handwheel State Estimation for Force Feedback

2004 ◽  
Author(s):  
Joshua P. Switkes ◽  
Ian A. Coe ◽  
J. Christian Gerdes
Keyword(s):  
Kalman Filter ◽  
Force Feedback ◽  
Low Frequency ◽  
Phase Lag ◽  
Position Sensor ◽  
Noisy Signal ◽  
Low Resolution ◽  
Moving Vehicle ◽  
Mems Accelerometers ◽  
Smooth Acceleration

This paper explores the possibility of combining solid state accelerometers with a low resolution position sensor to provide clean estimates of automobile handwheel position, velocity and acceleration for use in force feedback. Typically determining the acceleration and velocity of the handwheel requires differentiating a position sensor such as an encoder or potentiometer. Unless expensive high-resolution sensors are used, this differentiation leads to a noisy signal, requiring significant filtering which leads to significant phase lag. With a direct measurement of acceleration, we circumvent many of the problems associated with differentiation and filtering. This work uses a Kalman filter to combine a pair of MEMS accelerometers with a low-resolution potentiometer to estimate handwheel states. This measurement scheme is effective in this application because of the low frequency nature of the force feedback and because of the structural robustness of the handwheel system. Initial in-vehicle experimental results show the setup can provide smooth acceleration and velocity signals in a moving vehicle.

A capacitive angular sensor with flexible digitated electrodes

Sensor Review ◽  
2014 ◽  
Vol 34 (4) ◽  
pp. 382-388 ◽  
Author(s):  
Damir Krklješ ◽  
Dragana Vasiljević ◽  
Goran Stojanović
Keyword(s):  
Printed Electronics ◽  
Angular Displacement ◽  
Angular Position ◽  
Capacitive Sensor ◽  
Measurement Range ◽  
Content Type ◽  
Full Turn ◽  
Sensor Structure ◽  
Capacitor Structure ◽  
Incremental Encoder

Purpose – This paper aims to present a prototype of a capacitive angular-position sensor which exploits advantages of flexible/printed electronics. The novelty of the sensor is that the capacitor structure is placed at the circumference of the rotor and stator, that it posses two channels (capacitor structures) electrically shifted for p/4 and that the rotor is common for both channels. The electrodes of the sensing capacitor are digitated, providing a triangular transfer function. Design/methodology/approach – This sensor prototype consists of two flexible inkjet-printed silver electrodes forming a cylindrical capacitor structure. One of them is wrapped around the stator and another is wrapped around the rotor part of a simple mechanical platform used to precisely adjust the angular displacement. Findings – The capacitance as a function of angular position was measured using an inductance capacitance impedance (LCZ) Meter, and results are presented for a full-turn measurement range. The experimental results are compared with analytical ones and very good agreement has been achieved. Originality/value – The proposed capacitive sensor structure can be used as an absolute or an incremental encoder with different resolutions, and it can be applied in automotive industry or robotics.

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