current practices in railway track analysis and design are reviewed and discussed in this paper. the mechanical behavior of railway track structure comprising of various components has not been fully understood due to the railway track structural complexity. although there have been some improvements in the accuracy of current track design methods in recent decades, there are still considerable...

Times of downturn in economy, tough competition, high costs, and large amounts of capital required for replacements have created growing need for cost cutting measures and for seeking better return on investment. This has also placed an increasing emphasis on maintenance practices to extend the service life of existing railroad bridges. This paper outlines the various factors which playa role i...

宇宙開発 におけ る安全性 と経済性の要求か ら宇宙 ロボ ットに関す る研究1)~ηが進め られてい る.宇 宙 ロボ ット で大 きな問題 の一つ にエ ネルギ ーの供給法があ る.打 ち 上げ にかか るコス トが莫大なため,ロ ボ ットの質量は出 来 るだけ小 さくす る必要があ り,大 きなバ ッテ リーは積 み込めない.宇 宙空間では太陽かち無限にエネルギを引 き出す ことが出来 る.し か し太陽電 池の性能は,容 量 0.2~0.3(kW/m2),比 電 力50(W/kg)程 度8)であ り, マ ニピュレータの駆 動時 に必要 な電 力を太陽電 池のみか ら供給す るためには,通 常の運用時 の必要電 力に比べ て 過 大な容量 の太陽電 池 システムが必要 とな り,大 型化 を 招 く.ま たマ ニピュレータを制動す る際 に余剰 エネルギ を熱 として発生 さ...

this paper studies the key issue of fault tolerance for actively controlled railway wheelsets. It assesses failure modes in such systems, with a focus on actuator failures, and consequence of those hardware failures. It seeks to establish the necessary basis for control reconfiguration to ensure system stability and performance in the event of a faulty, without the need for hardware redundancie...

The proposed new lubricating composition, which significantly reduces the wear resistance of rails and wheels rolling stock during operation, prevents electrochemical corrosion friction pairs “wheel – rail” and, most importantly, stabilizes coefficient at optimum level after a relatively short operating time. experiments performed on pair “sample bandage material railway wheel sample rail mater...

The bounding gait for the Platform for Ambulating Wheels (PAW), a new and unique hybrid wheeled-leg system is presented here. Two hypotheses are tested and discussed: first, that the robot’s forward speed can be increased by increasing the leg liftoff angles and, second, that addition of distally-mounted actuated wheels can be used in running gaits such as the bound. Both hypotheses were tested...