All issues
Volume 51, Issue 7
Displaying 1-9 of 9 articles from this issue
- |<
- <
- 1
- >
- >|
Paper
-
Masahiro TANAKA, Shiro MASUDA2015 Volume 51 Issue 7 Pages 451-457
Published: 2015
Released on J-STAGE: August 11, 2015
JOURNAL FREE ACCESSThis paper proposes a data-driven controller design method for minimum variance control and analyzes convergence properties of the method. Data-driven controller design methods tune control parameters by minimizing a criterion which is derived from a single set of input and output data without a process model. However, optimization problems in these methods are generally non-convex. The analytical results show that a gradient descent algorithm can converge from the set of initial parameter values to the global minimum if the maximum-phase difference between the initial controllers and the minimum variance controller is smaller than π/2 radians.View full abstractDownload PDF (597K) -
Takahito YOSHIURA, Susumu HARA, Yoshifumi MORITA, Noritaka SATO, Yoji ...2015 Volume 51 Issue 7 Pages 458-467
Published: 2015
Released on J-STAGE: August 11, 2015
JOURNAL FREE ACCESSThis paper discusses manual motion control (MMC) problems. MMC problems are seen in conveyance of a large amount of products in factories and stores. One of the most successful examples of MMC is “power assist”. The power-assisted systems have been introduced to reduce workers' loads in industrial production. In near future, higher efficiency of works by power-assisted systems will be required. One of the methods to improve the efficiency is connection and cooperation of plural systems. Then, this paper utilizes power-assisted carts as a controlled object and proposes a control system realizing such conveyance on the basis of the principle of the power assist. In particular, smooth connection without any stops, invariant maneuverability and tumble prevention of conveyed objects are considered. The effectiveness of the proposed control system is verified by experiments and simulations.View full abstractDownload PDF (2599K) -
Yasushi MAHARA, Shiro MASUDA2015 Volume 51 Issue 7 Pages 468-474
Published: 2015
Released on J-STAGE: August 11, 2015
JOURNAL FREE ACCESSIn this paper, we propose a data-driven method for simultaneously updating a process model and controller for disturbance attenuation. Since the proposed method allows to both identify a process model and design the corresponding minimum variance controller, the identified model can be used for assessment or analysis of the control system before actual implemntation. In order to achieve system identification and minimum variance (MV) control, we introduce a data-driven criterion that consists of the input and output signals of the system which are driven by white noise. We also show that the parameters which theoretically optimize the poposed criterion are equivalent to the true process parameters and the MV controller parameters. The validity of the proposed method is illustrated in a numerical example.View full abstractDownload PDF (806K) -
Daiki KONO, Toshitaka NOMURA, Leo OTA, Yuriko SARUTA, Masatoshi SEKI, ...2015 Volume 51 Issue 7 Pages 475-483
Published: 2015
Released on J-STAGE: August 11, 2015
JOURNAL FREE ACCESSWe propose a gait rehabilitation method using an elbow driving device. We focused on a coordinative relationship between upper limbs and lower limbs in walking, and the phase difference between the onset timing of elbow flexion and foot contact timing was controlled by the device. At first, we estimated an ordinary phase difference in young people whose right knee is fixed in extension, using motion capture system. Then we compared three settings of the desired phase difference: standard condition, right forward condition, and left forward condition. In the standard condition, the desired phase difference of both legs was set to the ordinary phase difference. In the right and left forward conditions, the desired phase difference of right and left legs were set to a smaller value than that of left and right leg, respectively. The result suggests that the patients with spastic gait improved on their gait stability and symmetry using rhythmic motor input.View full abstractDownload PDF (2493K) -
Takatsugu ODA, Kenichiro NONAKA, Kazuma SEKIGUCHI2015 Volume 51 Issue 7 Pages 484-493
Published: 2015
Released on J-STAGE: August 11, 2015
JOURNAL FREE ACCESSThis paper investigates a robust path tracking control for four-wheel driving and steering vehicles. The proposed integrated control system aims at high maneuverability and robustness. The proposed controller is applied to the path tracking problem which is formulated utilizing time state control form. The inputs for path tracking are calculated by model predictive control considering the friction circle to realize the path-following. In addition, using sliding mode control, the proposed control system is robust against external disturbance or uncertainties which satisfy the matching condition. The approximated tire force usage rate is introduced in order to balance path-following performance and the robustness. The efficiency of the proposed control system is demonstrated through numerical simulations.View full abstractDownload PDF (1329K) -
Kaiji SUGIYAMA, Ichiro MARUTA, Toshiharu SUGIE2015 Volume 51 Issue 7 Pages 494-502
Published: 2015
Released on J-STAGE: August 11, 2015
JOURNAL FREE ACCESSThis paper discusses the stability analysis of the closed-loop systems with Active Disturbance Rejection Controllers. A necessary and sufficient condition is derived for a class of linear systems to be stabilized by the controllers. It turns out that the relative degree, and the minimum phase property of the plants plays a crucial role for the closed-loop stability. It is suggested how to choose the design parameters through simulation results. Finally, the effectiveness of ADRC is demonstrated through experiment using a magnetic levitation system.View full abstractDownload PDF (1074K) -
Minoru KANEMASA, Eitaro AIYOSHI2015 Volume 51 Issue 7 Pages 503-511
Published: 2015
Released on J-STAGE: August 11, 2015
JOURNAL FREE ACCESSCrossover is one of the most known nature inspired operations in heuristic optimization algorithms. It was traditionally inspired by the evolution of species, and it is well known for the capability of solving discrete optimization problems, which use integer valued vector. However, in recent years, algorithms such as Differential Evolution use it to solve continuous optimization problem, regardless of the fact that this usage is apart from the way species evolve using DNA sequence. This kind of crossover operation in continuous space creates new points in axis-wise directions, thus it is known that the performance of those algorithms using continuous crossover have different performance when we rotate the coordinate of an optimization problem. This is because uniform crossover is not a rotation invariant operation. In this paper, we consider of using rotationally invariant crossover called hypersphere crossover. However, since this crossover may not adopt to ill-conditioned problem with fixed radius, we propose scaling parameter and its tuning rule to change the radius of the hypersphere to compensate for the problem. We compare our proposal with traditional uniform crossover, and other rotation invariant crossover operations using many benchmarks. We use pair-wises ranked t-test to statistically verify the advantage of our proposal.View full abstractDownload PDF (1911K)
Short Paper
-
Aya IWAI, Hiroaki MORINAKA, Kouji ANDOU, Yoshiya TERAO2015 Volume 51 Issue 7 Pages 512-514
Published: 2015
Released on J-STAGE: August 11, 2015
JOURNAL FREE ACCESSIn order to define the measuring time on initial verification for a ultrasonic gas meter, measurement of the instantaneous flowrate was conducted by using a test facility with critical nozzles. The possibility of reduction in measuring time for initial verification was cleared.View full abstractDownload PDF (707K) -
Susumu HARA, Ryo ISHIKAWA, Masatsugu OTSUKI2015 Volume 51 Issue 7 Pages 515-517
Published: 2015
Released on J-STAGE: August 11, 2015
JOURNAL FREE ACCESSNext-generation lunar/planetary exploration spacecraft need to solve problems of conventional landing methods and mechanisms such as high rebound, impossibility of reuse and high cost. For this purpose, the authors discuss the landing method by means of Base-Extension Separation landing Mechanism (BESM) which uses energy conversion with springs and separable units. In conventional studies, its effectiveness was confirmed for a simple case based on single-axis restriction. However, the investigation of tumble prevention cannot be treated in the simple case. The purpose of this paper is the response analysis with a double-axis case and to discuss the robustness of BESM for more practical landing situations.View full abstractDownload PDF (1176K)
- |<
- <
- 1
- >
- >|