120 research outputs found

    Trajectory-Tracking Control of the Ball-And-Plate System

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    The Mechatronics group in the Mechanical Engineering department of Cal Poly is interested in creating a demonstration of a ball-and-plate trajectory tracking controller on hardware. The display piece will serve to inspire engineering students to pursue Mechatronics and control theory as an area of study. The ball-and-plate system is open-loop unstable, underactuated, and has complicated, nonlinear equations of motion. These features present substantial challenges for control - especially if the objective is trajectory tracking. Because the system is underactuated, common nonlinear trajectory tracking control techniques are ineffective. This thesis lays out a theoretical foundation for controlling the hardware. Several important concepts related to ball-and-plate trajectory tracking control are presented. Models of the system, with various assumptions, are given and used in deriving control law candidates. To limit project scope, reasonable control criteria are introduced and used to evaluate designs from the thesis. Several control architectures are explored, these being Full-State Feedback with Integral Action, Single-Input-Single-Output Sliding Mode, and Full-State Feedback with Feed Forward. The mathematical reasoning behind each is detailed, simulation results are shown to validate their practicality and demonstrate features of the architectures, and trajectory similarity measure studies are produced to evaluate controller performance for a wide range of setpoint functions. The Full-State Feedback with Feed Forward controller is recommended based on its theoretical advantages and compliance with the control criteria over the competing designs. The control architecture has a proof of asymptotic tracking in the linear model, has excellent performance in simulations that use a nonlinear plant model, and produces the most pleasing visual experience when viewed in animation

    The Effect of Weight on the Amount of Force on Ankle Joints During a Vertical Jump

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    Ankles are one of the most complex parts of the human body. The ankle consists of bones, muscles, and joints that all work together to carry the weight of the human body, meaning the ankle also faces the most pressure and injuries. The main goal of this class project and what we are trying to determine is whether or not weight is a factor that effects the amount of force that the ankle takes on when jumping. The angles of the ankles are also being monitored due to the fact that weight could also have a correlation with them. We predict that an increased amount of weight will correlate with an increased amount of force on the ankles, but smaller angles. This information could tell us whether or not someone is more prone to ankle injuries

    A arte do teatro

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    Versión dixitalizada da edición publicada no 2002, na Coruña, pola Biblioteca-Arquivo Teatral Francisco Pillado Mayor, v. 2

    Lettres de Milady Juliette Catesby a milady henriette Campley son amie

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    Sign.: []\p2\s, A-N\p8/4\s, O\p6\sAntep.Port. con viñeta xil

    Autonomous Airborne Multi-Rotor UAS Delivery System

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    Within current combat environments, there is a demand for rapid and extremely precise re-supply missions. Typical combat airdrops require long periods of planning and can produce a large signature in an operating environment which relies on stealth for various mission sets. Team Hermes, made up of four members from the West Point graduating class of 2019, offers a new re-supply method to answer this demand. The design will allow for the delivery of a quadcopter carrying 1.5 pounds of cargo within a 5-meter radius of an impact point on the ground

    Thromboelastography (TEG (R)) demonstrates that tinzaparin 4500 international units has no detectable anticoagulant activity after caesarean section

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    Background Low molecular weight heparin is routinely used for thromboprophylaxis in pregnancy and the puerperium. Consensus guidelines recommend waiting 10–12 h after administration of a thromboprophylactic dose of low molecular weight heparin before performing a neuraxial block or removing an epidural catheter. Thromboelastography (TEG®) has been reported to be sensitive to the effects of enoxaparin 4 h after administration. The purpose of this study was to use TEG to examine coagulation changes in the first 10 h after a thromboprophylactic dose of tinzaparin in an attempt to ratify the current consensus guidelines about timing of neuraxial blockade and epidural catheter removal. Methods Twenty-four women who had undergone caesarean delivery and were classified as low or intermediate risk of thrombosis were recruited. Blood samples were taken before subcutaneous administration of tinzaparin 4500 IU, and at 4, 8 and 10 h post-dose. Standard TEG analyses were performed using plain and heparinase cuvettes and samples were also sent for laboratory anti-Xa assay. Thromboelastograph profiles were analysed for a low molecular weight heparin effect. Results Analysis revealed no significant differences in R time, K time, alpha angle or maximum amplitude between plain and heparinase samples at any time point. Apart from a small statistically significant (P=0.033) decrease in maximum amplitude of 2.8% (95% CI 0.3 to 5.4%) at 4 h, there were no significant changes in coagulation for any TEG parameter. Anti-Xa levels were virtually undetectable in all patients over the 10 h period (median 0.00 U/mL; range 0.00–0.13 U/mL). Conclusion A thromboprophylactic dose of tinzaparin 4500 IU had little detectable effect on coagulation as assessed by TEG and anti-Xa assay. These findings support consensus guidelines which state that it is acceptable to perform neuraxial blockade or remove an epidural catheter 10–12 h after a thromboprophylactic dose of tinzaparin. Rather than suggesting a lack of anticoagulant activity, the findings indicate that TEG may not have the sensitivity to detect a tinzaparin effect when this dose is used in this patient group
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