EFFECTS OF MONITORING SIGNAL HYSTERESIS ON SPEED REGULATION FOR THE AERO-DERIVATIVE GAS TURBINE

Sensor aging and sensor failure are the common phenomena due to the high temperature and pressure environment for gas turbines, which can lead to hysteresis of monitoring signals. In this paper, a kind of aero-derivative gas turbine is taken as the research object. The hysteresis effects of single monitoring signal and coupling of multiple monitoring signals on speed control are mainly studied, and the analysis is carried out from the perspective of adjustment time, overshoot, fuel quantity and fuel quantity regulation output. The analysis results show that the pressure signal hysteresis will lead to speed suspension. The speed signal hysteresis will change the speed regulation into a multi-step mode. When the monitoring signal hysteresis is coupled, the effect of pressure signal hysteresis is greater than that of speed signal hysteresis. The results of this paper can provide a reference for the optimal design of speed control of aero-derivative gas turbine

Studies on SI engine simulation and air/fuel ratio control systems design

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.More stringent Euro 6 and LEV III emission standards will immediately begin execution on 2014 and 2015 respectively. Accurate air/fuel ratio control can effectively reduce vehicle emission. The simulation of engine dynamic system is a very powerful method for developing and analysing engine and engine controller. Currently, most engine air/fuel ratio control used look-up table combined with proportional and integral (PI) control and this is not robust to system uncertainty and time varying effects. This thesis first develops a simulation package for a port injection spark-ignition engine and this package include engine dynamics, vehicle dynamics as well as driving cycle selection module. The simulations results are very close to the data obtained from laboratory experiments. New controllers have been proposed to control air/fuel ratio in spark ignition engines to maximize the fuel economy while minimizing exhaust emissions. The PID control and fuzzy control methods have been combined into a fuzzy PID control and the effectiveness of this new controller has been demonstrated by simulation tests. A new neural network based predictive control is then designed for further performance improvements. It is based on the combination of inverse control and predictive control methods. The network is trained offline in which the control output is modified to compensate control errors. The simulation evaluations have shown that the new neural controller can greatly improve control air/fuel ratio performance. The test also revealed that the improved AFR control performance can effectively restrict engine harmful emissions into atmosphere, these reduce emissions are important to satisfy more stringent emission standards

New trends in electrical vehicle powertrains

The electric vehicle and plug-in hybrid electric vehicle play a fundamental role in the forthcoming new paradigms of mobility and energy models. The electrification of the transport sector would lead to advantages in terms of energy efficiency and reduction of greenhouse gas emissions, but would also be a great opportunity for the introduction of renewable sources in the electricity sector. The chapters in this book show a diversity of current and new developments in the electrification of the transport sector seen from the electric vehicle point of view: first, the related technologies with design, control and supervision, second, the powertrain electric motor efficiency and reliability and, third, the deployment issues regarding renewable sources integration and charging facilities. This is precisely the purpose of this book, that is, to contribute to the literature about current research and development activities related to new trends in electric vehicle power trains.Peer ReviewedPostprint (author's final draft

Advances in Spacecraft Systems and Orbit Determination

"Advances in Spacecraft Systems and Orbit Determinations", discusses the development of new technologies and the limitations of the present technology, used for interplanetary missions. Various experts have contributed to develop the bridge between present limitations and technology growth to overcome the limitations. Key features of this book inform us about the orbit determination techniques based on a smooth research based on astrophysics. The book also provides a detailed overview on Spacecraft Systems including reliability of low-cost AOCS, sliding mode controlling and a new view on attitude controller design based on sliding mode, with thrusters. It also provides a technological roadmap for HVAC optimization. The book also gives an excellent overview of resolving the difficulties for interplanetary missions with the comparison of present technologies and new advancements. Overall, this will be very much interesting book to explore the roadmap of technological growth in spacecraft systems

Sähköbussin nopeuden ja ohjauskulman säätö edellä ajavan ajoneuvon liike-radan seuraamisessa

Buses face problems when the capacity of a bus is limited but it should be larger to be able to carry more passengers. The capacity of a bus is already increased to its maximum that is allowed by the infrastructure. The capacity of a bus line could be increased by driving buses more frequently but it would increase costs, that is unwanted. Costs could be reduced by driving buses as platoons consisting of two buses where only the first bus would be operated by a professional driver and the second would be driven autonomously. Autonomous driving requires longitudinal and lateral control of a vehicle. The follower bus should be able to follow the path driven by the leader bus precisely and avoid inter-vehicular collisions while still driving as close together as possible to indicate other traffic that they move as a platoon. Lateral control is usually divided into path following and direct following methods in the literature. Path following methods include obtaining the path of the leader vehicle and following of that path. Path following methods are usually accurate in terms of lateral error but are complex and require a lot of computational capacity. Direct following methods are easy to compute but they do not guarantee precise path following. A simulation model consisting of two identical buses was developed. One longitudinal controller and four lateral control laws were proposed. Longitudinal controller was designed to work also in tight turns which is not usually investigated. Lateral control laws proposed were geometrical in nature and required only input as the relative position of the leader bus. Therefore, they did not require inter-vehicular communication. Longitudinal controller worked well for initialization of the system with inter-vehicular distances from 2 to 10 m. It worked well in acceleration and deceleration tests when both buses were loaded similarly but failed to prevent collisions when follower bus was loaded more heavily than the leader. In lateral controller tests, Pure Pursuit and Modified Pure Pursuit methods were able to follow the leader producing following lateral errors: 0,8 m and 1,1 m (steady-state tests), 0,8 m and 0,7 m (u-turn maneuver) and 0,3 m/0,4 m and 0,4 m/0,5 m (double lane change maneuver, 5 m/s/10 m/s respectively). Spline Pursuit method showed oscillatory behavior and did not follow the leader well. Circular Pursuit method showed also oscillatory behavior and did not follow the leader well. However, it showed better performance than the Spline Pursuit. It remains to be studied whether Pure Pursuit or Modified Pure Pursuit can challenge more sophisticated path following methods.Linja-autojen matkustajakapasiteetti on rajallinen, mikä aiheuttaa ongelmia, sillä sen tulisi olla suurempi. Kapasiteetti on jo nostettu suurimmalle mahdolliselle tasolle, mitä nykyinen infrastruktuuri mahdollistaa. Linja-autolinjan kapasiteettia voisi nostaa ajamalla linja-autoja tiheämmin. Tämä kuitenkin johtaa suurempiin kustannuksiin. Kustannuksia voisi vähentää ajamalla linja-autoja kahden ajoneuvon jonoina, joissa ensimmäistä ajo-neuvoa ohjaisi ammattilaiskuljettaja ja toinen olisi autonomisesti ohjattu. Autonominen ajaminen vaatii ajoneuvon nopeuden ja ohjauskulman säätöä. Seuraajalinja-auton pitää pystyä seuraamaan johtajalinja-auton ajamaa ajouraa tarkasti ja välttää törmäämistä johtajaan. Linja-autojen välinen etäisyys on kuitenkin oltava riittävän pieni, jotta se viestisi muulle liikenteelle, että ajoneuvot ajavat jonona. Kirjallisuus jakaa ohjauskulman säädön yleensä ajouran seuraamiseen ja suoraan seuraamiseen. Ajouran seuraaminen koostuu johtaja-ajoneuvon ajouran saamisesta ja tämän uran seuraamisesta. Ajouran seuraamisen metodit ovat yleensä tarkkoja poikittaisen virheen suhteen, mutta ovat monimutkaisia ja vaativat paljon laskennallista kapasiteettia. Suoran seuraamisen metodit ovat laskennallisesti kevyitä, mutta eivät takaa tarkkaa ajouran seuraamista. Kahdesta identtisestä linja-autosta koostuva simulaatiomalli kehitettiin. Yksi nopeussäädin ja neljä ohjauskulman säätölakia esitettiin. Nopeussäädin suunniteltiin toimimaan myös tiukoissa käännöksissä, mitä ei ole yleensä tutkittu. Ohjauskulman säätölait perustuivat geometriseen päättelyyn ja ne tarvitsivat vain johtajalinja-auton suhteellisen asentotiedon. Säätölait eivät vaatineet ajoneuvojen välistä kommunikaatiota. Nopeussäädin toimi järjestelmän alustamisessa ajoneuvojen välisen etäisyyden ollessa 2-10 m. Se toimi hyvin kiihdytys- ja jarrutustesteissä, kun molemmat linja-autot olivat lastattu identtisellä kuormalla, mutta epäonnistui estämään törmäämisen, kun seuraajalinja-auto oli lastattu suuremmalla kuormalla kuin johtaja. Ohjauskulman säädön testeissä Pure Pursuit ja Modified Pure Pursuit pystyivät seuraamaan johtajaa seuraavilla poikittaissuuntaisilla virheillä: 0,8 m ja 1,1 m (steady-state-testit), 0,8 m ja 0,7 m (u-käännös) ja 0,3 m/0,4 m ja 0,4 m/0,5 m (kaksoiskaistanvaihto, 5 m/s/10 m/s vastaavasti). Spline Pursuit käyttäytyi värähtelevästi eikä seurannut johtajaa hyvin. Circular Pursuit käyttäytyi värähtelevästi eikä seurannut johtajaa hyvin, mutta kuitenkin paremmin kuin Spline Pursuit. Jää nähtäväksi pystyykö Pure Pursuit tai Modified Pure Pursuit haastamaan monimutkaisempia ajouran seuraamisen metodeja

Advances in Fluid Power Systems

The main purpose of this Special Issue of “Advances in Fluid Power Systems” was to present new scientific work in the field of fluid power systems for hydraulic and pneumatic control of machines and devices used in various industries. Advances in fluid power systems are leading to the creation of new smart devices that can replace tried-and-true solutions from the past. The development work of authors from various research centres has been published. This Special Issue focuses on recent advances and smart solutions for fluid power systems in a wide range of topics, including: • Fluid power for IoT and Industry 4.0: smart fluid power technology, wireless 5G connectivity in fluid power, smart components, and sensors.• Fluid power in the renewable energy sector: hydraulic drivetrains for wind power and for wave and marine current power, and hydraulic systems for solar power. • Hybrid fluid power: hybrid transmissions, energy recovery and accumulation, and energy efficiency of hybrid drives.• Industrial and mobile fluid power: industrial fluid power solutions, mobile fluid power solutions, eand nergy efficiency solutions for fluid power systems.• Environmental aspects of fluid power: hydraulic water control technology, noise and vibration of fluid power components, safety, reliability, fault analysis, and diagnosis of fluid power systems.• Fluid power and mechatronic systems: servo-drive control systems, fluid power drives in manipulators and robots, and fluid power in autonomous solutions

Advanced Modeling, Control, and Optimization Methods in Power Hybrid Systems - 2021

The climate changes that are becoming visible today are a challenge for the global research community. In this context, renewable energy sources, fuel cell systems and other energy generating sources must be optimally combined and connected to the grid system using advanced energy transaction methods. As this reprint presents the latest solutions in the implementation of fuel cell and renewable energy in mobile and stationary applications such as hybrid and microgrid power systems based on the Energy Internet, blockchain technology and smart contracts, we hope that they will be of interest to readers working in the related fields mentioned above

Energy Management

Forecasts point to a huge increase in energy demand over the next 25 years, with a direct and immediate impact on the exhaustion of fossil fuels, the increase in pollution levels and the global warming that will have significant consequences for all sectors of society. Irrespective of the likelihood of these predictions or what researchers in different scientific disciplines may believe or publicly say about how critical the energy situation may be on a world level, it is without doubt one of the great debates that has stirred up public interest in modern times. We should probably already be thinking about the design of a worldwide strategic plan for energy management across the planet. It would include measures to raise awareness, educate the different actors involved, develop policies, provide resources, prioritise actions and establish contingency plans. This process is complex and depends on political, social, economic and technological factors that are hard to take into account simultaneously. Then, before such a plan is formulated, studies such as those described in this book can serve to illustrate what Information and Communication Technologies have to offer in this sphere and, with luck, to create a reference to encourage investigators in the pursuit of new and better solutions

Transient optimisation of a diesel engine

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