著者

藤井 文武 椎木 健裕 澁谷 景子 樫部 直人 丸山 章

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.84, no.861, pp.17-00495-17-00495, 2018 (Released:2018-05-25)

参考文献数

8

被引用文献数

1

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This paper proposes an algorithm to generate the augmented reference position trajectory for the realtime 3D robotic phantom system which is used in the quality assurance of the radiation therapy. Quality assuarance is the important clinical part of the radiation therapy which ensures the delivery of the prescribed dose to the tumor of the patient. High precision quality assurance can be a difficult task if the tumor exhibits respiratory induced motion inside the body of the patient, as the motion fluctuates along with time and it suffers large inter-patient difference. This paper presents several algorithms to modify and/or correct the reference tumor trajectory of the patient and generate the augmented reference trajectory sequence for the already existing and tuned control system of the robot manipulator to yield high precision tracking to the original tumor motion trajectory. Experimental validation has been carried out for four lung tumor trajectories in the clinical environment using equipments used in the radiotherapy treatment and it has been shown that the clinical demand on the precision of tumor motion tracking has been satisfied for all the four cases.

著者

立畠 健一 植田 好雄 劉 棟博 藤井 文武

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.16-00462-16-00462, 2017 (Released:2017-08-25)

参考文献数

15

被引用文献数

1

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This paper discloses the development of the improved Bouc-Wen model which captures the behavior of the rate dependent hysteresis of a piezoelectric actuator. The basic form of the Bouc-Wen model only exhibits symmetric hysteresis loop for a sinusoidal input with no DC offset, whereas the real world bi-morph type actuator occasionally exhibits asymmetric loop for the same stimuli. The present works also proposes the integration of the FIR filter to the model to capture phase lag caused by the structural oscillation of the actuator. Comparison of the modeling accuracy has been given with our recent work of adaptive Preisach model. The result shows that accuracy of the two models are almost the same but the intrinsic difference lies in the number of parameters to be determined to form a computable model: the proposed model has only 25 parameters whereas the adaptive Preisach model includes 5050 discretized distribution function values to establish a single model.

著者

藤井 文武 西野 誠 和田 憲造

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 C編 (ISSN:03875024)

巻号頁・発行日

vol.74, no.742, pp.1493-1500, 2008-06-25 (Released:2011-03-04)

参考文献数

12

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A new control algorithm to achieve trajectory following motion of a motorcycle is proposed in this paper. Presented algorithm is comprised of a feedforward term and a feedback term, the former of which intends to balance forces acting on a motorcycle that have adverse effects for roll motion stabilization, and the latter controls the steering and human lean angle to achieve trajectory following. What is to be emphasized is that the proposed control law is comparably simpler than the ones presented in the foregoing works on motorcycle motion control. Results of both numerical and actual experiments have been described to illustrate the effectiveness of the proposed algorithm.