著者

山藤 勝彦 山本 建 澤田 賢治

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.852, pp.16-00553-16-00553, 2017 (Released:2017-08-25)

参考文献数

11

被引用文献数

1

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This paper describes self-excited oscillation caused by coulomb friction of electromagnetic proportional valve. Especially, this research focuses on a hydraulic system in which electromagnetic proportional and pressure proportional valves are located tandem. In the system, the coulomb frictional force effects on the displacement direction of the spool of the former valve and the piston is established in the downstream region of the latter valve. Each valve is stable, but, the connection of them causes instability. This paper analyzes the mechanism of this unstable vibration and then investigates an anti-vibration design method. In analysis, this paper clarifies that the vibration is caused by an elastic deformation delay of the oil in the piston. This delay increases the phase delay of the spool due to the coulomb frictional force. After replacing the coulomb frictional force with hysteresis, the proposed method uses the describing function method to express phase delay phenomenon due to the coulomb frictional force. The describing function is the complex function which expresses an amplitude ratio and phase difference with the input and output of nonlinear element. The delay of a vibration factor is linearized by converting coulomb friction into hysteresis. The effectiveness of the proposed method is demonstrated via practical experiment and non-linear simulation results.

著者

山藤 勝彦 橋本 真 山本 建 澤田 賢治

出版者

公益社団法人 計測自動制御学会

雑誌

計測自動制御学会論文集 (ISSN:04534654)

巻号頁・発行日

vol.57, no.7, pp.324-333, 2021 (Released:2021-07-17)

参考文献数

13

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Judder is well known as a vibration that occurs in a dry clutch. In order to maintain the ride quality and quietness of dry clutches, research on judder analysis and mechanical design to suppress judder is actively pursued. This paper describes the design and implementation of robust control techniques as an approach to suppressing judder during gear shifting in traction-controlled transmissions. This paper is concerned with transmissions that exhibit strongly nonlinear frictional characteristics that can only be approximated by higher order polynomials. Specifically, the coefficient of friction varies significantly nonlinearly with the rotational speed during gear shifting. In this paper, the controller is designed by expressing this nonlinear property as the uncertainty of the frequency. Simulation and bench test results are presented to validate the validity of such an approach. The results show that judder-free shifting is possible with the proposed approach. Furthermore, the requirements of three controllers are presented by analyzing the robust controllers.

著者

山藤 勝彦 山本 建 橋本 真 新 誠一 澤田 賢治

出版者

一般社団法人日本機械学会

雑誌

年次大会 : Mechanical Engineering Congress, Japan

巻号頁・発行日

vol.2013, pp."J101012-1"-"J101012-5", 2013-09-08

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Judder is well known oscillation occurring in dry clutches. To maintain riding comfort and silence in dry clutches, a lot of studies of judder analysis and machine design suppressing judder have been done. This paper describes the design and implementation of a robust control technique as a judder suppression approach for clutch during shifting. We address the automatic transmission using dry clutches of which the μ-V characteristics show a complicated nonlinearity. Specifically, their friction coefficient varies non-linearly with respect to the rotational speed during shifting. In this paper, it is clarified that the non-linear μ-V characteristic can be expressed as frequency uncertainties and then the control system is constructed with H∞ control. To verify the validity of such the approach, the results of simulation and bench testing are presented. As a result, we see that the proposed approach allows us to achieve the shifting without judder. Furthermore, we show the three controller requirements by analyzing the robust controllers.