Machine Design Lab: Using Automotive Transmission Examples to Reinforce Understanding of Gear Train Analysis

In studying mechanical gear train analysis, some students struggle with relatively simple gear design concepts, and virtually all have difficulty with the complexities of planetary gear sets. This paper describes two labs developed for an undergraduate senior level machine design course. One lab uses a three-speed manual synchromesh transmission with parts of the case cut away to demonstrate the operation of the gears, shifting mechanism, bearings, and other aspects of the design. Students then count teeth and analyze the gear ratios using standard gear train analysis methods. The other lab uses a 1924 Ford Model T planetary transmission to observe how planetary gears can create two forward speeds and reverse from constant rotation of the engine. The students analyze the planetary gear set using relative velocity analysis, and the planetary gear set is used to gain insight into basic principles of modern automatic transmissions. The two labs give students hands-on learning experience that clarifies difficult concepts and teaches students basic principles of gear train design, operation, and analysis

Operation Simulation and Control of a Hybrid Vehicle Based on a Dual Clutch Configuration

Today, the world thrives on making more fuel-efficient vehicles that consume less energy, emit fewer emissions and have enhanced overall performance. Hybrid Electric Vehicles (HEVs) offer the advantages of improved fuel economy and emissions without sacrificing vehicle performance factors such as safety, reliability and other features. The durability and performance enhancements of HEVs have encouraged researchers to develop various hybrid power-train configurations and improve associated issues, such as component sizing and control strategies. HEVs with dual clutch transmissions (HDCT) are used in operation modes to improve fuel efficiency and dynamic performance for both diesel engines and high-speed gas engines. Dual clutch transmissions (DCTs) are proved to be the first automatic transmission type to provide better efficiency than manual transmissions. DCTs also provide reduced shift shocks and shift time that result in better driving experience. In addition, advanced software allows more simplistic approaches and tunable launch strategies in HDCT development. In this dissertation, an innovative approach to develop a desired mode controller for a HDCT configuration is proposed. This mode controller allows the driver to select the desired driving style of the vehicle. The proposed controller was developed based on adaptive control theory for the overall HDCT system. The proposed Model Reference Adaptive Control (MRAC) was applied to a parallel hybrid electric vehicle with dual clutch transmission (HDCT), and yielded good performance under different conditions. This implies that the MRAC is adaptive to different torque distribution strategies. The current study, which was performed on adaptive control applications, revealed that the Lyapunov method was effective and yielded good performance. The MRAC method was also applied to the mode transition of an HDCT bus. The simulation results confirmed that the MRAC outperformed the conventional operation method for an HDCT with reduced vehicle jerk and the torque interruption for the driveline and with improved fuel efficiency.Ph.D.College of Engineering & Computer ScienceUniversity of Michigan-Dearbornhttps://deepblue.lib.umich.edu/bitstream/2027.42/145173/1/Final Dissertation Elzaghir.pdfDescription of Final Dissertation Elzaghir.pdf : Dissertatio

Product Lifecycle Management - Application of Patterning Methods to Gas Turbine Blades and Creation of Learning Materials

To compete in the global marketplace, companies need to embrace virtual design and manufacturing methods. Product Lifecycle Management (PLM) embodies both the workflow processes and tools to bring forth products from conception to design to fabrication to service to decommissioning, and to eventual recycling. In response to the growing demand for engineers and technicians with these critical skills, colleges and universities should introduce these virtual tools through seminars, software workshops, and computer laboratory sessions. Some of the opportunities in the PLM Center at Clemson University include short courses on PLM practices, focused software training sessions, hands-on exploration activities, and research projects. The participants across campus include creative inquiry students, capstone design classes, graduate researchers, and community outreach for K-12 students. Through these interactions, participants will gain insight into the challenges and opportunities with virtual engineering processes and software. The recent worldwide pandemic has demonstrated the need for engineers skilled in virtual design methods to enable the digital design, manufacturing, and support processes to occur in, and remote of, the workplace. Computer-aided design (CAD) and computer-aided engineering (CAE) methods embody the software tools that bring forth products from conception to design. A variety of packages are available, which allow for the progress of a product to be tracked and detailed changes to be made along the way. One complex product currently designed using CAE software is a natural gas fired turbine for electrical power generation. In these thermo-dynamic rotational systems, blade cooling using internal forced airflow is vital to withstand the operating temperatures in the combustion chamber. Accordingly, ribbed surface disruptors, known as turbulators, are placed inside the turbine blades to promote air mixing to help remove heat from the hot surfaces. Three CAE patterning features will be examined to create these turbulators with evaluation metrics based on the execution speed, accessibility, accuracy, adaptability, and relevance. The numerical case study results revealed that the face pattern method was the most suitable option with productivity time improvements of 5% in comparison to the feature and geometry pattern approaches. The feature pattern method proved to be viable for smaller modeling changes which require significant detail. However, the geometry patterning method did not show any indications of being a usable option over the others in any scenario tested. To prepare the next generation of engineers for these PLM processes and software tools, a PEER & WISE workshop module has been created for students to engage with these virtual concepts. In these four-day, 90-minute sessions, middle school students will learn about engineering design processes, fundamental engineering and science concepts, and CAD software. They will create virtual mechanical components using CAD software, while hands-on tasks will enable the creation of mechanical assemblies using discrete components to demonstrate the functionality of gears and drivelines. To assess the student experience, a survey was created and submitted for IRB approval. The pandemic created a unique situation for these prepared sessions as students could not participate right away, however, they will be offered in the future

Mechanical Engineering

The book substantially offers the latest progresses about the important topics of the "Mechanical Engineering" to readers. It includes twenty-eight excellent studies prepared using state-of-art methodologies by professional researchers from different countries. The sections in the book comprise of the following titles: power transmission system, manufacturing processes and system analysis, thermo-fluid systems, simulations and computer applications, and new approaches in mechanical engineering education and organization systems

Advanced Torque Control Strategy for the Maha Hydraulic Hybrid Passenger Vehicle.

An increase in the number of vehicles per capita coupled with stricter emission regulations have made the development of newer and better hybrid vehicle architectures indispensable. Although electric hybrids have more visibility and are now commercially available, hydraulic hybrids, with their higher power densities and cheaper components have been rigorously explored as the alternative. The most commonly used architecture is the series hybrid, which requires a power conversion from the primary source (engine) to the secondary domain. A positive displacement machine (pump) converts the rotational power of the engine into hydraulic power and a second positive displacement machine (motor) converts the hydraulic power back into rotational power to drive the axle or wheel. Having at least one variable displacement unit enables the system of the pump and the motor to form a continuously variable transmission. A series hybrid also includes a secondary power storage device, which in most cases is a high-pressure hydro-pneumatic accumulator. During braking, power flows from the wheels, which drive the second positive displacement machine into the high-pressure accumulator and during acceleration, the power flow is reversed, i.e. power from the high-pressure accumulator is used as an input for the second positive displacement machine which will run in motoring mode and drive the axle or wheel. A mode-switching hydraulic hybrid, which is a combination of a hydrostatic transmission and a series hybrid was recently developed at the Maha Fluid Power Research Center. This thesis focuses on the development of a new torque-based controller for the mode-switching hydraulic hybrid prototype. The aim of this work is to use a uniform control strategy across all vehicle modes instead of multiple controllers for multiple modes. With that in mind, an entirely new system model is developed. This torque-based control strategy, along-with a supervisory controller decides on the usage of the high-pressure accumulator, thereby switching the vehicle from non-hybrid to hybrid mode. A separate engine speed controller is designed to control the engine throttle based on the measured engine speed and a piecewise constant reference engine speed. The model is simulated using standard drive cycles demonstrating the different vehicle modes of operation and the controller action. The architecture of the existing prototype vehicle is modified to implement the new controller and also to prevent leakages when the vehicle is not in use. The data acquisition system is modified to incorporate new installed components. Lastly, baseline measurements taken with the prototype vehicle are compared with the simulations. This improved control strategy allows the vehicle to operate in higher powertrain efficiencies and the uniform nature of the controller results in a better “driver-feel”

Integracija električnih vozila u energetske i transportne sustave

There is a strong tendency of development and application of different types of electric vehicles (EV). This can clearly be beneficial for transport systems in terms of making it more efficient, cleaner, and quieter, as well as for energy systems due to the grid load leveling and renewable energy sources exploitation opportunities. The latter can be achieved only through application of smart EV charging technologies that strongly rely on application of optimization methods. For the development of both EV architectures and controls and charging optimization methods, it is important to gain the knowledge about driving cycle features of a particular EV fleet. To this end, the paper presents an overview of (i) electric vehicle architectures, modeling, and control system optimization and design; (ii) experimental characterization of vehicle fleet behaviors and synthesis of representative driving cycles; and (iii) aggregate-level modeling and charging optimization for EV fleets, with emphasis on freight transport.U novije vrijeme postoji izražena težnja za razvojem i korištenjem različitih tipova električnih vozila. Ovo može biti korisno sa stanovišta transportnih sustava u smislu omogućavanja efikasnijeg, čišćeg, i tišeg transporta, kao i iz perspektive energetskih sustava zbog dodatnih potencijala za poravnanje opterećenja mreže i iskorištenje obnovljivih izvora energije. Potonje može biti ostvareno samo kroz korištenje tehnologija naprednog punjenja električnih vozila, koje se često temelje na primjeni optimizacijskih postupaka. Za razvoj prikladnih konfiguracija, upravljačkih sustava te metoda pametnog punjenja električnih vozila, potrebno je steći uvid u značajke voznih ciklusa razmatrane flote električnih vozila. Imajući u vidu navedeno, članak predstavlja pregled (i) konfiguracija i modeliranja električnih vozila, te optimiranja i sinteze njihova upravljačkog sustava; (ii) eksperimentalne karakterizacije ponašanja flote vozila i sinteze reprezentativnih voznih ciklusa; te (iii) modeliranja i optimiranja punjenja flote električnih vozila na agregatnom nivou, s naglaskom na teretni transport

Prognostic-based Life Extension Methodology with Application to Power Generation Systems

Practicable life extension of engineering systems would be a remarkable application of prognostics. This research proposes a framework for prognostic-base life extension. This research investigates the use of prognostic data to mobilize the potential residual life. The obstacles in performing life extension include: lack of knowledge, lack of tools, lack of data, and lack of time. This research primarily considers using the acoustic emission (AE) technology for quick-response diagnostic. To be specific, an important feature of AE data was statistically modeled to provide quick, robust and intuitive diagnostic capability. The proposed model was successful to detect the out of control situation when the data of faulty bearing was applied. This research also highlights the importance of self-healing materials. One main component of the proposed life extension framework is the trend analysis module. This module analyzes the pattern of the time-ordered degradation measures. The trend analysis is helpful not only for early fault detection but also to track the improvement in the degradation rate. This research considered trend analysis methods for the prognostic parameters, degradation waveform and multivariate data. In this respect, graphical methods was found appropriate for trend detection of signal features. Hilbert Huang Transform was applied to analyze the trends in waveforms. For multivariate data, it was realized that PCA is able to indicate the trends in the data if accompanied by proper data processing. In addition, two algorithms are introduced to address non-monotonic trends. It seems, both algorithms have the potential to treat the non-monotonicity in degradation data. Although considerable research has been devoted to developing prognostics algorithms, rather less attention has been paid to post-prognostic issues such as maintenance decision making. A multi-objective optimization model is presented for a power generation unit. This model proves the ability of prognostic models to balance between power generation and life extension. In this research, the confronting objective functions were defined as maximizing profit and maximizing service life. The decision variables include the shaft speed and duration of maintenance actions. The results of the optimization models showed clearly that maximizing the service life requires lower shaft speed and longer maintenance time

Hydrostatic-Mechanical Power Split CVT

This thesis involved the study of the hydrostatic-mechanical power split CVT technology. Based on the theoretical model, the steady state characteristics were studied to display the advantage and disadvantage of this transmission, then a market application review was made to show the practical application of this technology, finally suitability study was carried out based on dynamic model, to find out the working cycle suitability and power range suitability of this transmission technology. /Kir1