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Chūō-ku, Japan

Zhang J.,IHI Corporation | Choi W.,IHI Corporation | Ito T.,IHI Corporation | Takahashi K.,IHI Corporation | Fujita M.,IHI Transport Machinery Co.
Fuel | Year: 2016

To predict the spontaneous heating of coal pile by computational fluid dynamics (CFD) is very meaningful for preventing the coal pile from self-ignition. A two-dimensional (2-D) numerical model, which could be simply implemented in FLUENT, was developed in this study. The chemical kinetic parameters of low-temperature oxidation of coal, which were expressed by the outer surface area of particles, were well measured in experiments. The coal piles under different conditions were calculated by using the developed model and measured kinetic parameters, in order to make clear the effects of some important factors. The simulation results indicated the evaporation of moisture from coal played a critical role. The pile height, coal type, wind velocity, and heat loss from bottom have significant effects on the process of spontaneous heating of coal pile. According to these effects, in order to increase the heat loss of pile and then effectively inhibit the self-ignition, the low pile height, good ventilation surrounding the pile, and ground material with high thermal conductivity below the pile should be used. The model developed in this model is expected to become a reliable tool to predict the spontaneous heating of coal pile. © 2016 Elsevier Ltd. All rights reserved. Source

Tanida K.,IHI Transport Machinery Co.
Nihon Kikai Gakkai Ronbunshu, C Hen/Transactions of the Japan Society of Mechanical Engineers, Part C | Year: 2010

A crane mounted on a tower-like flexible structure called Tower Crane has a problem that fast transfer of the load causes the sway of the load and the vibration of the flexible structure. Our objective is to reduce both the sway and the vibration using the controller for motors which drive the boom, while an operator gives some commands to transfer the load. We have proposed the gain-scheduled H∞ control method to design the controller, and have already shown its efficiency for a onethirty fifths scale model of the tower crane. In this paper the controller for an actual tower crane is designed and implemented in the existing control system and its effectiveness is verified from the experimental results. Source

Yonezawa N.,Tohoku University | Kashiwazaki K.,Tohoku University | Kosuge K.,Tohoku University | Hirata Y.,Tohoku University | And 6 more authors.
Proceedings - IEEE International Conference on Robotics and Automation | Year: 2012

This article describes the concept of a novel car transportation system including two mobile robots with a lift mechanism for single wheel. The system lifts only two drive wheels of a front-wheel-drive vehicle or a rear-wheel-drive vehicle, and transports them. However, the system has nonholonomic constraints because all wheels of a vehicle are not lifted by the system. This article also describes a motion control method and a vehicle's wheelbase estimate algorithm for the proposed system in order to maneuver the vehicle. The motion control method is based on control theory for a three-wheeled cycle system. On the other hand, the vehicle's wheelbase estimate algorithm includes impedance control, and the system estimates the vehicle's wheelbase from constraint forces during transporting the vehicle. Finally, two experiments show that the proposed system can maneuver the vehicle. © 2012 IEEE. Source

Kashiwazaki K.,Tohoku University | Yonezawa N.,Tohoku University | Endo M.,Nihon University | Kosuge K.,Tohoku University | And 6 more authors.
IEEE International Conference on Intelligent Robots and Systems | Year: 2011

This paper proposes a new car transportation system, iCART II (intelligent Cooperative Autonomous Robot Transporters - type II), based on "a-robot-for-a-wheel" concept. A prototype system, MRWheel (a Mobile Robot for a Wheel), is designed and downsized less than the half of the conventional robot used in iCART (intelligent Cooperative Autonomous Robot Transporters). In general, it is very difficult for mobile robots such as MRWheel to move to desired positions without motion errors caused by slipping, etc. Therefore we propose a decentralized control algorithm for car transportation in coordination by using a leader-follower type multiple robot system. The proposed algorithm enables the followers to estimate and reduce the motion errors and then enables the robots to transport a car to a desired position, even if the motion errors occur. In addition, we discuss how the external force applied to each robot during transporting a car, such as an inertial and friction force, is shared among the robots, and we propose a model-based external force estimation and compensation method. The proposed control algorithm is applied to the system, and the results of car transportation experiment confirm its validity. © 2011 IEEE. Source

Kashiwazaki K.,Tohoku University | Kosuge K.,Tohoku University | Hirata Y.,Tohoku University | Sugahara Y.,Kokushikan University | And 4 more authors.
2012 IEEE International Conference on Robotics and Biomimetics, ROBIO 2012 - Conference Digest | Year: 2012

This paper proposes a new cooperative transportation control algorithm in consideration of not only the internal force but the external force applied to 'Mobile Robot for a Wheel (MRWheel)'. First, we describe the merits and demerits of the model-based external force compensation method proposed in our previous study and explain the necessity of this new control algorithm. Secondly, we explain this new control algorithm mathematically. In this new algorithm, each follower receives the motion errors estimated by the other followers with TCP/IP, which enables each follower to estimate its motion error by using the force applied to it. Moreover, this new algorithm also enables 'intelligent Cooperative Autonomous Robot Transporters-type II (iCART II)' to transport many types of cars at a variety of places without the preliminary car transportation needed for identifying the model parameters of the external force. Finally, we conduct the transportation experiments of two types of cars for the comparison between this new algorithm and the conventional algorithm with the modelbased external force compensation method. These experimental results illustrate the validity of this new control algorithm. © 2012 IEEE. Source

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