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Hiro-o Yamazaki - One of the best experts on this subject based on the ideXlab platform.

  • Adaptive Sliding Mode Control of Adhesion Force in Railway Rolling Stocks
    Sliding Mode Control, 2011
    Co-Authors: Jong Shik Kim, Sung Hwan Park, Jeong Ju Choi, Hiro-o Yamazaki
    Abstract:

    Studies of braking mechanisms of railway rolling stocks focus on the Adhesion Force, which is the tractive friction Force that occurs between the rail and the wheel (Kadowaki, 2004). During braking, the wheel always slips on the rail. The Adhesion Force increases or decreases according to the slip ratio, which is the difference between the velocity of the rolling stocks and the tangential velocity of each wheel of the rolling stocks normalized with respect to the velocity of the rolling stocks. A nonzero slip ratio always occurs when the brake caliper holds the brake disk, and thus the tangential velocity of the wheel so that the velocity of the wheel is lower than the velocity of the rolling stocks. Unless an automobile is skidding, the slip ratio for an automobile is always zero. In addition, the Adhesion Force decreases as the rail conditions change from dry to wet (Isaev, 1989). Furthermore, since it is impossible to directly measure the Adhesion Force, the characteristics of the Adhesion Force must be inferred based on experiments (Shirai, 1977). To maximize the Adhesion Force, it is essential to operate at the slip ratio at which the Adhesion Force is maximized. In addition, the slip ratio must not exceed a specified value determined to prevent too much wheel slip. Therefore, it is necessary to characterize the Adhesion Force through precise modeling. To estimate the Adhesion Force, observer techniques are applied (Ohishi, 1998). In addition, based on the estimated value, wheel-slip brake control systems are designed (Watanabe, 2001). However, these control systems do not consider uncertainty such as randomness in the Adhesion Force between the rail and the wheel. To address this problem, a reference slip ratio generation algorithm is developed by using a disturbance observer to determine the desired slip ratio for maximum Adhesion Force. Since uncertainty in the traveling resistance and the mass of the rolling stocks is not considered, the reference slip ratio, at which Adhesion Force is maximized, cannot always guarantee the desired wheel slip for good braking performance. In this paper, two models are developed for the Adhesion Force in railway rolling stocks. The first model is a static model based on a beam model, which is typically used to model automobile tires. The second model is a dynamic model based on a bristle model, in which the friction interface between the rail and the wheel is modeled as contact between bristles (Canudas de Wit, 1995). The validity of the beam model and bristle model is verified through an Adhesion test using a brake performance test rig.

  • modeling and control of Adhesion Force in railway rolling stocks
    IEEE Control Systems Magazine, 2008
    Co-Authors: Sung Hwan Park, Jeong Ju Choi, Jong Kim, Hiro-o Yamazaki
    Abstract:

    In this article, two models are developed for the Adhesion Force in railway rolling stocks. The first model is a static model based on a beam model, which is typically used to model automobile tires. The second model is a dynamic model based on a bristle model, in which the friction interface between the rail and the wheel is modeled as contact between bristles. The validity of the beam model and bristle model is verified through an Adhesion test using a brake performance test rig. We also develop wheel-slip brake control systems based on each friction model. One control system is a conventional proportional-integral (PI) control scheme, while the other is an adaptive sliding mode control (ASMC) scheme. The controller design process considers system uncertainties such as the traveling resistance, disturbance torque, and variation of the Adhesion Force according to the slip ratio and rail conditions. The mass of the rolling stocks is also considered as an uncertain parameter, and the adaptive law is based on Lyapunov stability theory. The performance and robustness of the PI and adaptive sliding mode wheel-slip brake control systems are evaluated through computer simulation.

Sung Hwan Park - One of the best experts on this subject based on the ideXlab platform.

  • Adaptive Sliding Mode Control of Adhesion Force in Railway Rolling Stocks
    Sliding Mode Control, 2011
    Co-Authors: Jong Shik Kim, Sung Hwan Park, Jeong Ju Choi, Hiro-o Yamazaki
    Abstract:

    Studies of braking mechanisms of railway rolling stocks focus on the Adhesion Force, which is the tractive friction Force that occurs between the rail and the wheel (Kadowaki, 2004). During braking, the wheel always slips on the rail. The Adhesion Force increases or decreases according to the slip ratio, which is the difference between the velocity of the rolling stocks and the tangential velocity of each wheel of the rolling stocks normalized with respect to the velocity of the rolling stocks. A nonzero slip ratio always occurs when the brake caliper holds the brake disk, and thus the tangential velocity of the wheel so that the velocity of the wheel is lower than the velocity of the rolling stocks. Unless an automobile is skidding, the slip ratio for an automobile is always zero. In addition, the Adhesion Force decreases as the rail conditions change from dry to wet (Isaev, 1989). Furthermore, since it is impossible to directly measure the Adhesion Force, the characteristics of the Adhesion Force must be inferred based on experiments (Shirai, 1977). To maximize the Adhesion Force, it is essential to operate at the slip ratio at which the Adhesion Force is maximized. In addition, the slip ratio must not exceed a specified value determined to prevent too much wheel slip. Therefore, it is necessary to characterize the Adhesion Force through precise modeling. To estimate the Adhesion Force, observer techniques are applied (Ohishi, 1998). In addition, based on the estimated value, wheel-slip brake control systems are designed (Watanabe, 2001). However, these control systems do not consider uncertainty such as randomness in the Adhesion Force between the rail and the wheel. To address this problem, a reference slip ratio generation algorithm is developed by using a disturbance observer to determine the desired slip ratio for maximum Adhesion Force. Since uncertainty in the traveling resistance and the mass of the rolling stocks is not considered, the reference slip ratio, at which Adhesion Force is maximized, cannot always guarantee the desired wheel slip for good braking performance. In this paper, two models are developed for the Adhesion Force in railway rolling stocks. The first model is a static model based on a beam model, which is typically used to model automobile tires. The second model is a dynamic model based on a bristle model, in which the friction interface between the rail and the wheel is modeled as contact between bristles (Canudas de Wit, 1995). The validity of the beam model and bristle model is verified through an Adhesion test using a brake performance test rig.

  • modeling and control of Adhesion Force in railway rolling stocks
    IEEE Control Systems Magazine, 2008
    Co-Authors: Sung Hwan Park, Jeong Ju Choi, Jong Kim, Hiro-o Yamazaki
    Abstract:

    In this article, two models are developed for the Adhesion Force in railway rolling stocks. The first model is a static model based on a beam model, which is typically used to model automobile tires. The second model is a dynamic model based on a bristle model, in which the friction interface between the rail and the wheel is modeled as contact between bristles. The validity of the beam model and bristle model is verified through an Adhesion test using a brake performance test rig. We also develop wheel-slip brake control systems based on each friction model. One control system is a conventional proportional-integral (PI) control scheme, while the other is an adaptive sliding mode control (ASMC) scheme. The controller design process considers system uncertainties such as the traveling resistance, disturbance torque, and variation of the Adhesion Force according to the slip ratio and rail conditions. The mass of the rolling stocks is also considered as an uncertain parameter, and the adaptive law is based on Lyapunov stability theory. The performance and robustness of the PI and adaptive sliding mode wheel-slip brake control systems are evaluated through computer simulation.

Jeong Ju Choi - One of the best experts on this subject based on the ideXlab platform.

  • Adaptive Sliding Mode Control of Adhesion Force in Railway Rolling Stocks
    Sliding Mode Control, 2011
    Co-Authors: Jong Shik Kim, Sung Hwan Park, Jeong Ju Choi, Hiro-o Yamazaki
    Abstract:

    Studies of braking mechanisms of railway rolling stocks focus on the Adhesion Force, which is the tractive friction Force that occurs between the rail and the wheel (Kadowaki, 2004). During braking, the wheel always slips on the rail. The Adhesion Force increases or decreases according to the slip ratio, which is the difference between the velocity of the rolling stocks and the tangential velocity of each wheel of the rolling stocks normalized with respect to the velocity of the rolling stocks. A nonzero slip ratio always occurs when the brake caliper holds the brake disk, and thus the tangential velocity of the wheel so that the velocity of the wheel is lower than the velocity of the rolling stocks. Unless an automobile is skidding, the slip ratio for an automobile is always zero. In addition, the Adhesion Force decreases as the rail conditions change from dry to wet (Isaev, 1989). Furthermore, since it is impossible to directly measure the Adhesion Force, the characteristics of the Adhesion Force must be inferred based on experiments (Shirai, 1977). To maximize the Adhesion Force, it is essential to operate at the slip ratio at which the Adhesion Force is maximized. In addition, the slip ratio must not exceed a specified value determined to prevent too much wheel slip. Therefore, it is necessary to characterize the Adhesion Force through precise modeling. To estimate the Adhesion Force, observer techniques are applied (Ohishi, 1998). In addition, based on the estimated value, wheel-slip brake control systems are designed (Watanabe, 2001). However, these control systems do not consider uncertainty such as randomness in the Adhesion Force between the rail and the wheel. To address this problem, a reference slip ratio generation algorithm is developed by using a disturbance observer to determine the desired slip ratio for maximum Adhesion Force. Since uncertainty in the traveling resistance and the mass of the rolling stocks is not considered, the reference slip ratio, at which Adhesion Force is maximized, cannot always guarantee the desired wheel slip for good braking performance. In this paper, two models are developed for the Adhesion Force in railway rolling stocks. The first model is a static model based on a beam model, which is typically used to model automobile tires. The second model is a dynamic model based on a bristle model, in which the friction interface between the rail and the wheel is modeled as contact between bristles (Canudas de Wit, 1995). The validity of the beam model and bristle model is verified through an Adhesion test using a brake performance test rig.

  • modeling and control of Adhesion Force in railway rolling stocks
    IEEE Control Systems Magazine, 2008
    Co-Authors: Sung Hwan Park, Jeong Ju Choi, Jong Kim, Hiro-o Yamazaki
    Abstract:

    In this article, two models are developed for the Adhesion Force in railway rolling stocks. The first model is a static model based on a beam model, which is typically used to model automobile tires. The second model is a dynamic model based on a bristle model, in which the friction interface between the rail and the wheel is modeled as contact between bristles. The validity of the beam model and bristle model is verified through an Adhesion test using a brake performance test rig. We also develop wheel-slip brake control systems based on each friction model. One control system is a conventional proportional-integral (PI) control scheme, while the other is an adaptive sliding mode control (ASMC) scheme. The controller design process considers system uncertainties such as the traveling resistance, disturbance torque, and variation of the Adhesion Force according to the slip ratio and rail conditions. The mass of the rolling stocks is also considered as an uncertain parameter, and the adaptive law is based on Lyapunov stability theory. The performance and robustness of the PI and adaptive sliding mode wheel-slip brake control systems are evaluated through computer simulation.

E. Dendy Sloan - One of the best experts on this subject based on the ideXlab platform.

  • MICROMECHANICAL Adhesion Force MEASUREMENTS BETWEEN CYCLOPENTANE HYDRATE PARTICLES
    2008
    Co-Authors: Laura E. Dieker, Craig Taylor, E. Dendy Sloan
    Abstract:

    Cyclopentane hydrate interparticle Adhesion Force measurements were performed in pure cyclopentane liquid using a micromechanical Force apparatus. Cyclopentane hydrate Adhesion Force measurements were compared to those of cyclic ethers, tetrahydrofuran and ethylene oxide, which were suspected to be cyclic ether-lean and thus contain a second ice phase. This additional ice phase led to an over-prediction of the hydrate interparticle Forces by the capillary bridge theory. The Adhesion Forces obtained for cyclopentane hydrate at atmospheric pressure over a temperature range from 274-279 K were lower than those obtained for the cyclic ethers at similar subcoolings from the formation temperature of the hydrate. The measured cyclopentane interparticle Adhesion Forces increased linearly with increasing temperature, and are on the same order of magnitude as those predicted by the Camargo and Palermo rheology model.

  • HYDRATE PARTICLES Adhesion Force MEASUREMENTS: EFFECTS OF TEMPERATURE, LOW DOSAGE INHIBITORS, AND INTERFACIAL ENERGY
    2008
    Co-Authors: Craig Taylor, Laura E. Dieker, Kelly T. Miller, Carolyn A. Koh, E. Dendy Sloan
    Abstract:

    Micromechanical Adhesion Force measurements were performed on tetrahydrofuran (THF) hydrate particles in n-decane. The experiments were performed at atmospheric pressure over the temperature range 261–275 K. A scoping study characterized the effects of temperature, anti-agglomerants, and interfacial energy on the particle Adhesion Forces. The Adhesion Force between hydrate particles was found to increase with temperature and the interfacial energy of the surrounding liquid. The Adhesion Force of hydrates was directly proportional to the contact time and contact Force. Both sorbitan monolaurate (Span20) and poly-Nvinyl caprolactam (PVCap) decreased the Adhesion Force between the hydrate particles. The measured Forces and trends were explained by a capillary bridge between the particles.

  • Micromechanical Adhesion Force measurements between tetrahydrofuran hydrate particles.
    Journal of colloid and interface science, 2006
    Co-Authors: Craig Taylor, Laura E. Dieker, Kelly T. Miller, Carolyn A. Koh, E. Dendy Sloan
    Abstract:

    Adhesion Forces between tetrahydrofuran (THF) hydrate particles in n-decane were measured using an improved micromechanical technique. The experiments were performed at atmospheric pressure over the temperature range 261-275 K. The observed Forces and trends were explained by a capillary bridge between the particles. The Adhesion Force of hydrates was directly proportional to the contact Force and contact time. A scoping study examined the effects of temperature, anti-agglomerants, and interfacial energy on the particle Adhesion Forces. The Adhesion Force of hydrates was found to be directly proportional to interfacial energy of the surrounding liquid, and to increase with temperature. Both sorbitan monolaurate (Span20) and poly-N-vinyl caprolactam (PVCap) decreased the Adhesion Force between the hydrate particles.

Carolyn A. Koh - One of the best experts on this subject based on the ideXlab platform.

  • Adhesion Force between cyclopentane hydrates and solid surface materials.
    Journal of colloid and interface science, 2009
    Co-Authors: Guro Aspenes, Laura E. Dieker, Carolyn A. Koh, Zach Aman, Sylvi Høiland, Amadeu K. Sum, E.d. Sloan
    Abstract:

    The mechanisms by which hydrates deposit in a petroleum production line are related to pipeline surface properties, fluid composition and properties, and water cut. In this work, Adhesion Forces between cyclopentane hydrates and solid surfaces were investigated as a function of the solid material, the presence of water and the presence of petroleum acids in the oil phase. The influence of dissolved water on hydrate Adhesion Forces was also investigated. The results show that the Adhesion Force between hydrates and solid surfaces was dependent on the surface material; solids with low surface free energy lead to the lowest Adhesion Forces. The Adhesion Force was strongly dependent on the presence of water in the system. When a water drop was deposited on the solid surface, the Adhesion Force between the hydrate and the solid surface was more than 10 times larger than hydrate-hydrate Adhesion Forces. The presence of a water-saturated oil phase also led to an increase in Adhesion Force between hydrate particles. Adhesion Forces were highest when the solid surfaces are water-wet. Addition of petroleum acids to the oil phase drastically reduced Adhesion Forces.

  • HYDRATE PARTICLES Adhesion Force MEASUREMENTS: EFFECTS OF TEMPERATURE, LOW DOSAGE INHIBITORS, AND INTERFACIAL ENERGY
    2008
    Co-Authors: Craig Taylor, Laura E. Dieker, Kelly T. Miller, Carolyn A. Koh, E. Dendy Sloan
    Abstract:

    Micromechanical Adhesion Force measurements were performed on tetrahydrofuran (THF) hydrate particles in n-decane. The experiments were performed at atmospheric pressure over the temperature range 261–275 K. A scoping study characterized the effects of temperature, anti-agglomerants, and interfacial energy on the particle Adhesion Forces. The Adhesion Force between hydrate particles was found to increase with temperature and the interfacial energy of the surrounding liquid. The Adhesion Force of hydrates was directly proportional to the contact time and contact Force. Both sorbitan monolaurate (Span20) and poly-Nvinyl caprolactam (PVCap) decreased the Adhesion Force between the hydrate particles. The measured Forces and trends were explained by a capillary bridge between the particles.

  • Micromechanical Adhesion Force measurements between tetrahydrofuran hydrate particles.
    Journal of colloid and interface science, 2006
    Co-Authors: Craig Taylor, Laura E. Dieker, Kelly T. Miller, Carolyn A. Koh, E. Dendy Sloan
    Abstract:

    Adhesion Forces between tetrahydrofuran (THF) hydrate particles in n-decane were measured using an improved micromechanical technique. The experiments were performed at atmospheric pressure over the temperature range 261-275 K. The observed Forces and trends were explained by a capillary bridge between the particles. The Adhesion Force of hydrates was directly proportional to the contact Force and contact time. A scoping study examined the effects of temperature, anti-agglomerants, and interfacial energy on the particle Adhesion Forces. The Adhesion Force of hydrates was found to be directly proportional to interfacial energy of the surrounding liquid, and to increase with temperature. Both sorbitan monolaurate (Span20) and poly-N-vinyl caprolactam (PVCap) decreased the Adhesion Force between the hydrate particles.