A built-in displacement sensor for an electrostatic film motor

Nishijima, Takashi; Yamamoto, Akio; Yasui, Hidehiko; Higuchi, Toshiro

doi:10.1088/0957-0233/17/10/020

Cited by 15 publications

(10 citation statements)

References 14 publications

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“…Attitude information is extremely important for the accuracy of motor motion control, orientation control, and processing [16][17][18]. Moreover, attitude and speed information are two of the most important parameters for motor system control and early diagnosis purposes [19][20][21]. The method of attitude estimation and the selection of its sensors largely determines the success and accuracy of attitude estimation.…”

Section: Attitude Estimation Of a Permanent Magnet Spherical Motor Ba...mentioning

confidence: 99%

Attitude estimation of a permanent magnet spherical motor based on an improved fast discriminative scale space tracking algorithm

Xue

Wang

et al. 2020

Meas. Sci. Technol.

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A permanent magnet spherical motor (PMSM) can perform a three-degree-of-freedom operation. The estimation of the attitude of the rotor is one of the key steps for realizing the closed-loop control of PMSM. An attitude estimation method based on a target-tracking algorithm is proposed in this study. Firstly, a high-speed camera is used to capture a video sequence of the spherical motor in motion. The location of the target is obtained by introducing an improved fast discriminative scale space tracking (IFDSST) algorithm to track the video sequence. In consideration of the motor's output shaft being covered with load, the singletarget tracking algorithm is improved into a multi-target tracking algorithm. Markers, which are symmetrical with respect to the output shaft, are made on the surface of the rotor, and their attitudes are obtained from the images captured by the tracking algorithm. Secondly, the attitude of the output shaft is estimated by the coordinate transformation and the positional relationship between the markers and the output shaft. The effectiveness and superiority of the proposed algorithm are verified by comparing it with a micro-electromechanical system (MEMS) method and a fast -complementary filter (FCF) method. Three types of motor motions, including yaw, spin, and tilt, are tested in the experiments, and the average angle error or trajectory error of the proposed IFDSST method reduces around 33%, 53%, and 79% as compared with those of the MEMS and FCF methods, respectively. Experiments show that the proposed algorithm can effectively and accurately measure the attitude of the motor's rotor.

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Section: Attitude Estimation Of a Permanent Magnet Spherical Motor Ba...mentioning

confidence: 99%

Attitude estimation of a permanent magnet spherical motor based on an improved fast discriminative scale space tracking algorithm

Xue

Wang

et al. 2020

Meas. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…The above-mentioned sensors utilize exclusive electrodes for their sensing; the electrode sheet contains both driving electrodes and sensing electrodes on its surface. On the other hand, Nishijima et al proposed a technique to utilize the driving electrodes for displacement sensing by superposing highfrequency sensor signals onto low-frequency driving signals using transformers [15].…”

Section: Electrostatic Film Motor and Its Displacement Sensorsmentioning

confidence: 99%

“…In the original proposal in [6], the sensor utilized threephase parallel and straight electrodes as shown in figure 1. On the other hand, the later implementations [14,15] have utilized three-phase skewed electrodes [12], since skewed electrodes can realize better resolutions. The same applies to actuation; originally, the motor utilized parallel electrodes, but some recent studies have utilized skewed electrodes to obtain smoother motion.…”

Section: Basic Analysis Of the Displacement Sensormentioning

confidence: 99%

A flexible sensor measuring displacement and bending

Nishijima

Yamamoto

Higuchi

2009

Meas. Sci. Technol.

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This paper proposes a new sensor that is capable of measuring both linear displacement and bending. The sensor is designed to be used with an electrostatic film motor that features mechanical flexibility, but can also be used as an independent sensor. The sensor employs three-phase electrodes both in sliding and stationary parts and estimates displacement and bending from the change of the capacitance between the electrodes. The paper describes an equivalent capacitance-network model for the sensor. Based on the model, sensing principles for both displacement and bending are presented and analyzed. The analyses are experimentally verified using a prototype sensor. The experimental results show that the prototype sensor could measure both displacement and bending with little interference between them.

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“…Since there is a kind of duality between electromagnetic and electrostatic actuators, a similar self-sensing concept can be applied to electrostatic actuators. Various types of self-sensing, or built-in sensing, have been studied for electrostatic actuators, ranging from micro ones [ 38 , 39 , 40 , 41 , 42 ] to large-scale ones [ 43 , 44 , 45 , 46 , 47 , 48 ] including film actuators. Table 1 summarizes built-in sensing for film actuators.…”

Section: Introductionmentioning

confidence: 99%

Slider Sheet Detection in Charge-Induction Electrostatic Film Actuators

Kojima

Yoshimoto

Yamamoto

2023

Sensors

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This work analyzes a built-in slider detection method for a charge-induction type electrostatic film actuator with a high surface-resistance slider. In the detection method, one stator electrode is detached from the parallel driving electrodes and is dedicated to sensing. When a slider with induced charges moves over the sensing electrode, electrostatic induction occurs in the sensing electrode, which causes an electric current. The current is converted to a voltage through a detection resistance, which will be an output of the sensing circuit. This paper provides a framework to analyze the output signal waveform and shows that the waveform consists of two components. One component is caused by driving voltage and appears regardless of the existence of a slider. The other component corresponds to the movement of a slider, which appears only when a slider is moving over the sensing electrode. Therefore, the slider can be detected by monitoring the latter component. The two components generally overlap, which makes the detection of the latter component difficult in some cases. This paper proposes a method to decouple the two components by switching the detection resistance at an appropriate time. These methods are verified using a prototype actuator that has an electrode pitch of 0.6 mm. The actuator was driven with a set of pulse voltages with an amplitude of 1000 V. The experimental results show similar waveforms to the analytical results, verifying the proposed analytical framework. The performance of the sensing method as a proximity sensor was verified in the experiments, and it was confirmed that the slider can be detected when it approaches the sensing electrode within about 3 mm.

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A built-in displacement sensor for an electrostatic film motor

Cited by 15 publications

References 14 publications

Attitude estimation of a permanent magnet spherical motor based on an improved fast discriminative scale space tracking algorithm

Attitude estimation of a permanent magnet spherical motor based on an improved fast discriminative scale space tracking algorithm

A flexible sensor measuring displacement and bending

Slider Sheet Detection in Charge-Induction Electrostatic Film Actuators

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