All issues
Volume 46, Issue 5
Displaying 1-7 of 7 articles from this issue
- |<
- <
- 1
- >
- >|
Paper
Measurement
-
Yuichi KURITA, Junya KOBAYASHI, Tsuyoshi SUENAGA, Tsukasa OGASAWARA2010 Volume 46 Issue 5 Pages 257-265
Published: 2010
Released on J-STAGE: November 03, 2011
JOURNAL FREE ACCESSGood communication among workers helps make comfortable atmosphere in an office and contributes to the increase company productivity. Therefore, relationship between workers is an important information the manager needs to know by examining the worker's comfort level in an office environment. There are many non-contact systems that can measure the positions of multiple persons in a room by using cameras and laser range sensors. However, who-is-who information is difficult to obtain in these systems without special devices, such as identification tags. This study proposes a personal identification method by using movement trajectories that are measured using cameras. Hidden Markov Model is used to obtain who-is-who information. Moreover, visualization method of the relationship between workers is proposed based on the physical distance established among workers in an office throughout a day. The validity of the visualized relationships obtained by the proposed system is confirmed by comparing its results with that from self-evaluation questionnaires about a worker's strength of relationship with their co-workers.View full abstractDownload PDF (1482K)
Control
-
Masato ISHIKAWA, Takahiro FUJINO2010 Volume 46 Issue 5 Pages 266-273
Published: 2010
Released on J-STAGE: November 03, 2011
JOURNAL FREE ACCESSThis paper is concerned with a new approach to the locomotion control of the trident snake robot, focusing on its double-linked case where the robot is composed of a triangular body and three branches of double-linked snake-like legs. Originally, this robot was proposed by the authors as a novel example of nonholonomic mobile robot. The well-known Lie Algebra Rank Condition (LARC) for its nonlinear controllability has an odd structure that it contains two generator vector-fields and higher order Lie brackets, which makes its control problem extremely challenging. In this paper, for this difficult control problem, we first propose a design algorithm which partially achieves the desired locomotion. Then we point out that the resulting motion may or may not be a stable limit cycle, depending on the eigenvalues of the corresponding discrete-time dynamics on its Poincaré map. Finally, we propose a full controller design by combining the stable limit cycles. The validity of the proposed idea is examined by numerical simulations.View full abstractDownload PDF (1492K)
Systems and Information
-
Kei SENDA, Yoshimitsu IWASAKI, Shinji FUJII2010 Volume 46 Issue 5 Pages 274-280
Published: 2010
Released on J-STAGE: November 03, 2011
JOURNAL FREE ACCESSThis study defines the certification sampling that guarantees with specified reliability the optimal policy being correct to the real transition probability, where the optimal policy was derived from a estimated probability. It then discusses the sampling policy as follows that efficiently obtains the certification sampling. The the transition probability is estimated by sampling, and it leads the optimal policy. On the other hand, it calculates the desired accuracy of the estimated transition probability that is necessary to guarantee the correct optimal policy. This study proposes the sampling policy that efficiently achieves the certification sampling with the desired accuracy of the estimated transition probability. The proposed method is efficient in number of samples because it automatically selects states and actions to be sampled and stops sampling when the condition is satisfied.View full abstractDownload PDF (822K) -
Takeshi MUTO, Tetsuya KANAI, Hiroshi SAKUTA, Yoshihiro MIYAKE2010 Volume 46 Issue 5 Pages 281-288
Published: 2010
Released on J-STAGE: November 03, 2011
JOURNAL FREE ACCESSIn this research, we applied the gait training method which takes in the rhythmic auditory stimulation as a pace maker to the assistance of gait motion, and analyzed the dynamical stability of the period and trajectory of the lower limbs' motions. As the result, it was clarified that, in the training style which presents a constant rhythm, trajectory of ankles was modified as the stable state which has the historical property, but the period of footsteps was not modified but susceptible to the external environment. This result suggests that the hierarchical modification mechanism of motor schema of gait is realized by the connection between the immediate and historical modification system.View full abstractDownload PDF (826K) -
Takahiro WADA, Makoto YOSHIDA, Shun'ichi DOI, Shigeyoshi TSUTSUMI2010 Volume 46 Issue 5 Pages 289-295
Published: 2010
Released on J-STAGE: November 03, 2011
JOURNAL FREE ACCESSThis paper proposes a method to characterize hurried driving from the viewpoint of attention allocation. In overtaking, drivers need to manage the collision risk by allocating their attention appropriately, thus mental workload of the driver tends to be increased in such situation. However, hurry impulses likely arise in such situations even though it is risky. Therefore, relationship between collision risks between surround vehicles and attention allocation will be investigated in overtaking. It will be shown that hurried driving can be characterized by outlier from the modeled distribution of the normal driving in terms of relationship between the collision risk toward the lead vehicle and the continuous gaze time to the rear-side vehicle. Furthermore, a method to detect hurried driving will be proposed by applying the results.View full abstractDownload PDF (1796K)
System Integration
-
Sayaka KANATA, Hiroaki NAKANISHI, Tetsuo SAWARAGI2010 Volume 46 Issue 5 Pages 296-305
Published: 2010
Released on J-STAGE: November 03, 2011
JOURNAL FREE ACCESSWe proposed a method of localization for a space rover, which is useful for a rover even on a small planetary body with diameter less than 1000m. It measures round-trip propagation delay between the rover and a mother spacecraft based on radio waves. Together with these measurement data, information of rotational parameters of the small planetary body is used for localization in this method. Simulation results suggested that uncertainty in the direction of the rotation axis of the small planetary body has a serious effect on the localization accuracy. In this paper, a method to estimate the rotational parameters of the small planetary body together with the position of the rover is proposed. Estimation method of the rotational parameters are formulated as an optimization problem. Normal method based on gradient is useless to solve this optimization problem because the performance index has different scales of sensitivity to each estimation parameter. In order to avoid this problem, minimum search based on the gradient was divided into three steps. Numerical simulations assumed a rover on a small planetary body are shown to evaluate the estimation accuracy of the proposed method. Discussions about the sensitivity direction of the proposed method are also described here.View full abstractDownload PDF (1031K)
Short Paper
-
Tadashi EGAMI, Keisuke AMANO, Masahiro NISHIKAWA2010 Volume 46 Issue 5 Pages 306-308
Published: 2010
Released on J-STAGE: November 03, 2011
JOURNAL FREE ACCESSWe propose a method of path tracking control with variable velocity for vehicles. The nearest desired point from the present position is searched. The vehicle system is transformed to time-state control form consists of the directional vector and the path error.View full abstractDownload PDF (439K)
- |<
- <
- 1
- >
- >|