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Articles 391 - 396 of 396

Full-Text Articles in Mechanical Engineering

Sliding Mode Measurement Feedback Control For Antilock Braking Systems, Cem Unsal, Pushkin Kachroo Mar 1999

Sliding Mode Measurement Feedback Control For Antilock Braking Systems, Cem Unsal, Pushkin Kachroo

Electrical & Computer Engineering Faculty Research

We describe a nonlinear observer-based design for control of vehicle traction that is important in providing safety and obtaining desired longitudinal vehicle motion. First, a robust sliding mode controller is designed to maintain the wheel slip at any given value. Simulations show that longitudinal traction controller is capable of controlling the vehicle with parameter deviations and disturbances. The direct state feedback is then replaced with nonlinear observers to estimate the vehicle velocity from the output of the system (i.e., wheel velocity). The nonlinear model of the system is shown locally observable. The effects and drawbacks of the extended Kalman filters …


Long-Term Effects Of Neutron Absorber And Fuel Matrix Corrosion On Criticality, William Culbreth, P. Zielinski May 1994

Long-Term Effects Of Neutron Absorber And Fuel Matrix Corrosion On Criticality, William Culbreth, P. Zielinski

Mechanical Engineering Faculty Research

Proposed waste package designs will require the addition of neutron absorbing material to prevent the possibility of a sustained chain reaction occurring in the fuel in the event of water intrusion. Due to the low corrosion rates of the fuel matrix and the Zircaloy cladding, there is a possibility that the neutron absorbing material will corrode and leak from the waste container long before the subsequent release of fuel matrix material. An analysis of the release of fuel matrix and neutron absorber material based on a probabilistic model was conducted and the results were used to prepare input to KENO-V, …


Variable Structure End Point Control Of A Flexible Manipulator, Shailaja Chenumalla, Sahjendra N. Singh Jul 1993

Variable Structure End Point Control Of A Flexible Manipulator, Shailaja Chenumalla, Sahjendra N. Singh

Electrical & Computer Engineering Faculty Research

We treat the question of control and stabilization of the elastic multibody system developed in the Phillips Laboratory, Edwards Air Force Base, California. The controlled output is judiciously chosen such that the zero dynamics are stable or almost stable. A variable structure control (VSC) law is derived for the end point trajectory control. Although, the VSC law accomplishes precise end point tracking, elastic modes are excited during the maneuver of the arm. A Linear stabilizer is designed for the final capture of the terminal state.


Optimization Of The Seating Position In A Human-Powered Vehicle, Y. Lei, Mohamed Trabia, D. Too Jun 1993

Optimization Of The Seating Position In A Human-Powered Vehicle, Y. Lei, Mohamed Trabia, D. Too

Mechanical Engineering Faculty Research

Until recently, most of the human-powered vehicles (HPV) were designed focusing solely on its aerodynamics characteristic. In many of these HPV designs, the rider seating position was arbitrarily chosen without consideration of its effect on the rider's comfort and cycling effectiveness. Also, there is no guarantee that the seating position is related to maximum power output. Too (1991) used an experimental approach to determine that the rider will produce the maximum anaerobic power when the seat tube angle of a bicycle is at 75° whereas Hull and Gonzalez (1990) used an engineering approach to optimize the cycling biomechanics. However several …


Measurement Of Thermal-Energy Charge-Transfer Rate Coefficient Of Mo6+ And Argon, Victor H.S. Kwong, Z. Fang, Yingtao Jiang, T. T. Gibbons, L. D. Gardner Jul 1992

Measurement Of Thermal-Energy Charge-Transfer Rate Coefficient Of Mo6+ And Argon, Victor H.S. Kwong, Z. Fang, Yingtao Jiang, T. T. Gibbons, L. D. Gardner

Electrical & Computer Engineering Faculty Research

The charge-transfer rate coefficient of Mo6+ and argon has been measured at mean ion energies of 8.8 and 1.4 eV using a laser-ablation ion source and an ion trap. The rate coefficient deduced from these measurements is 1.02(0.10)×10-10 cm3 s-1 and appears to be independent of the mean ion energy at this energy range. However, the measured value is an order of magnitude smaller than the Langevin rate coefficient.


Energy Transmission Into The Human Hand From Vibrating Tools, Douglas D. Reynolds Jan 1987

Energy Transmission Into The Human Hand From Vibrating Tools, Douglas D. Reynolds

Mechanical Engineering Faculty Research

A method for calculating power transmitted to the hands of operators who use vibrating hand tools is presented. Results that relate to a comprehensive multidiscipline NIOSH field study of several hundred chipper and grinder workers who used pneumatic hand tools are discussed. These results indicated that the total power in the frequency range of 6.3 to 1000 Hz transmitted to the hand ranged from 1080 to 7230 J/s for the chisel and from 0.852 to 157 J/s the handle of chipping hammers. For pneumatic grinders the power transmitted to the hands of the tool operators was in the range of …