H ∞ and μ-synthesis Design of Quarter Car Active Suspension System

To improve the street managing and passenger comfort of a vehicle, a suspension system is furnished. An active suspension device is considered to be better than the passive suspension device. In this paper, 2 degree of freedom of an active suspension system of a linear vehicle are designed, that's challenge to oneof-a-kind disturbances on the road. Since the parametric uncertainty inside the spring, the shock absorber, the mass and the actuator has been taken into consideration, robust control is used. In this paper, H∞ and µ-synthesis controllers are used to enhance using consolation and the capability to force the car on the road. For the analysis of the time domain, a MATLAB script software become used and a check with 4 road disturbance inputs (bump, random, sinusoidal and harmonic) became carried out for suspension deflection, body acceleration and travel of the body for the energetic suspension with the H∞ controller and the active suspension with the µ-synthesis controller and the comparative simulation and the reference consequences display the effectiveness of the active suspension system with the µ-synthesis controller

Bridging Physics and Biology Teaching through Modeling

As the frontiers of biology become increasingly interdisciplinary, the physics education community has engaged in ongoing efforts to make physics classes more relevant to life sciences majors. These efforts are complicated by the many apparent differences between these fields, including the types of systems that each studies, the behavior of those systems, the kinds of measurements that each makes, and the role of mathematics in each field. Nonetheless, physics and biology are both sciences that rely on observations and measurements to construct models of the natural world. In the present theoretical article, we propose that efforts to bridge the teaching of these two disciplines must emphasize shared scientific practices, particularly scientific modeling. We define modeling using language common to both disciplines and highlight how an understanding of the modeling process can help reconcile apparent differences between the teaching of physics and biology. We elaborate how models can be used for explanatory, predictive, and functional purposes and present common models from each discipline demonstrating key modeling principles. By framing interdisciplinary teaching in the context of modeling, we aim to bridge physics and biology teaching and to equip students with modeling competencies applicable across any scientific discipline.Comment: 10 pages, 2 figures, 3 table

Dual output variable pitch turbofan actuation system

An improved actuating mechanism was provided for a gas turbine engine incorporating fan blades of the variable pitch variety, the actuator adapted to rotate the individual fan blades within apertures in an associated fan disc. The actuator included means such as a pair of synchronizing ring gears, one on each side of the blade shanks, and adapted to engage pinions disposed thereon. Means were provided to impart rotation to the ring gears in opposite directions to effect rotation of the blade shanks in response to a predetermined input signal. In the event of system failure, a run-away actuator was prevented by an improved braking device which arrests the mechanism

Racing car chassis

Cílem této bakalářské práce je analýza současných konceptů podvozků závodních okruhových aut. V první části práce je zpracován historický vývoj, charakteristika kol a pneumatik s reprezentací dobře známých produktů. V druhé části je popsán systém odpružení, pružné média a tlumící členy. Systémy odpružení je zde rozdělen na nezávisle a polozávislé zavěšení kol a odpružení pevných náprav. Následující oddíl této práce je zaměřený na standardní kontrolní systémy, jako jsou ABS, ESC a TSC. Závěr přináší rychlé shrnutí této problematiky.The aim of this bachelor thesis is to analyse contemporary concepts of circuit race car chassis. In the first part of the thesis, the historical evolution is described and then wheels and tires characteristic within some well-known brand products are represented. The second important part includes the suspension systems, springing medium and damping members. The suspension systems are further divided to independent and semi-independent solutions and rigid axle suspensions. The end of this thesis deals with the standard braking control systems, such as ABS, ESC and TCS. The conclusion brings the quick summary of this subject.

Single ion heat engine with maximum efficiency at maximum power

We propose an experimental scheme to realize a nano heat engine with a single ion. An Otto cycle may be implemented by confining the ion in a linear Paul trap with tapered geometry and coupling it to engineered laser reservoirs. The quantum efficiency at maximum power is analytically determined in various regimes. Moreover, Monte Carlo simulations of the engine are performed that demonstrate its feasibility and its ability to operate at maximum efficiency of 30% under realistic conditions.Comment: 5 pages, 3 figure

ЕКСПЕРТНЕ ДОСЛІДЖЕННЯ З ВИЗНАЧЕННЯ ПРИЧИН НЕСПРАВНОСТІ СИСТЕМИ АКТИВНОЇ СТАБІЛІЗАЦІЇ ACTIVE CURVE SYSTEM АВТОМОБІЛЯ MERCEDES-BENZ GLS500 4MATIC

Establishing of causes and circumstances that could affect failure of both parts individually and mechanisms generally of the “Active curve system” active stabilization system in Mercedes-benz GLS500 4MATIC cars is considered. The relevance of this scientific paper is due to novelty of installing an active stabilizer on vehicles which ensures minimal car body roll. Design, a principle of work and forensic expert research while inspection and study of the “Active curve system” active stabilization system of Mercedes-benz GLS500 4MATIC using modern equipment and research methods are presented. Measures to prevent failure of structural parts and systems are considered, which will ensure reliable and safe work of the “Active curve system” active stabilization system in the process of operation. The system allows you to keep a car within the path set by a driver in various driving modes (acceleration, braking, moving along a straight line, while road curves and free rolling). Determination of occurrence of a traffic collision is carried out by comparing actions of a driver and parameters of a car. In case when a driver’s actions (desired driving parameters) differ from the actual vehicle motion parameters, the “Active curve system” active stabilization system recognizes the situation as uncontrolled and starts working. In case of understeer, the “Active curve system” active stabilization system prevents a car from slipping out of turning trajectory by slowing down a rear inner wheel and changing an engine torque. In case of oversteer, skidding of a car during turns is prevented by slowing down a front outer wheel and changing an engine torque. Operation in this case is of a cyclical nature: pressure increase, pressure containment and pressure relief in the “Active curve system” active stabilization system. The system that combines the system of electronic stability control, steering and car suspension is called vehicle dynamics management integrated system.Розглянуто причини і обставини, які могли вплинути на вихід із ладу як деталей, так і механізмів загалом системи активної стабілізації Active curve system автомобіля Mercedes-Benz GLS500 4Matic. Актуальність цієї роботи зумовлена новизною встановлення на транспортні засоби активного стабілізатору, що забезпечує мінімальний крен кузова. Наведено конструкцію, принцип роботи й дослідження судового експерта під час огляду й обстеження системи активної стабілізації Active curve system автомобіля Mercedes-Benz GLS500 4Matic із використанням сучасних приладів і прийомів дослідження. Розглянуто заходи запобігання виходу з ладу конструктивних елементів та систем, що дасть змогу забезпечити надійну й безпечну роботу системи активної стабілізації Active curve system у процесі експлуатації