Double Clutch Research Articles

First Description of a Double Clutch, and Interisland Movements of a Pueo (Hawaiian Short-Eared Owl; Asio flammeus sandwichensis) in Hawaii, USA

First Description of a Double Clutch, and Interisland Movements of a Pueo (Hawaiian Short-Eared Owl; Asio flammeus sandwichensis) in Hawaii, USA

Successful captive breeding of vultures due to the double clutching method.

After a massive decline, the Griffon Vulture (Gypsfulvus) population in Bulgaria has now stabilised as a result of the hard work of conservation programmes, although it is still listed as an Endangered species (EN) in the country's Red Data Book. Due to a series of unfortunate events, another species - the Cinereous Vulture (Aegypiusmonachus) became extinct in Bulgaria and recovered only recently due to systematic re-introduction efforts. Along with the poor living conditions, a predisposing factor for the decreasing population of the vultures is the fact they hatch only a single egg; two may be laid on exceptions. The survival rate of the young is from medium to low. In that order, a method of double clutching has been applied in the hope of preserving and retrieving both of the vultures. This article aims to introduce the double clutching method in detail, as well as to show the results of its implementation into the breeding programme of the Cinereous Vulture and the Griffon Vulture at the Wildlife Rehabilitation and Breeding Centre of Green Balkans - Stara Zagora NGO. This research studies the time period 2019-2023. The purpose of this study is to compare the results of natural copulation and hatching and those of the double clutching method. The data taken are used for studies for both the Cinereous and the Griffon Vulture's reproduction in correlation with their feeding programme and living conditions. The results of the study will be summarised into the following text for the purposes of shedding light on the positives of the double clutching method.

Innovative powertrain and advanced energy management strategy for hybrid hydraulic excavators

This paper presents an innovative powertrain managed by an advanced energy management strategy for hybrid hydraulic excavators to improve the overall energy efficiency. Here, a main pump is driven via a planetary gear by an engine and an electric motor/generator. A double clutch is integrated to adjust torque and speed of engine according to efficiency map enabling higher working efficiency. Potential energy of the boom cylinder can be converted and stored in a battery through an energy regeneration system. The advanced energy management strategy is designed by utilising extremum seeking and fuzzy techniques to optimally distribute power requirement. A fuzzy logic system is designed based on consideration of battery performance and aging to adjust a penalty function subsequently improving the overall system performance while prolonging the component lifetime. Simulations and real-time experiments have been carried out to evaluate the effectiveness of the proposed powertrain managed by the advanced energy management strategy.

Аналіз конструктивних особливостей різних типів коробок перемикання передач автомобілів

One of the important components of the car design is the gearbox, which is part of the transmission. It is the gearbox that is responsible for changing the direction of the car and its speed. This affects traction and dynamic properties in general. The purpose of this article is to analyze the design features of various types of car gearboxes. The work analyzes the design features of various types of car gearboxes. The purpose of the gearbox, the effect on the traction-speed properties, which are a set of properties that determine the possible speed ranges and the maximum intensity of acceleration when the car is moving in the traction mode in various operating conditions, are given, as well as the main requirements that it should provide. The peculiarities of the construction of mechanical gearboxes, their structure, the principle of operation and the possibility of placement in a car are considered. The structure and main elements of the hydromechanical transmission (HMT) design are presented. It consists of three main parts: a torque converter, a manual gearbox and a control system. The design features of the gearbox with V-belt and toroid variators are considered. The principle of operation of variators, which ensures a stepless change of the gear ratio within the established limits, is presented. The design of the gearbox with a double clutch is considered, which ensures uninterrupted transmission of the power flow to the drive wheels. The gearbox is controlled by an electronic control unit, which receives information from sensors located in the box and is connected by a high-speed bus to the engine's electronic control unit. The main advantages and disadvantages of each type of considered gearboxes are highlighted. The mechanical gearbox has proven itself as a unit that is simple in design and reliable in operation. The prospects for the development of the gearbox are the development of new electronic control systems, the use of modern materials with high performance indicators and the use of high-performance methods of mechanical processing.

Breakeven Points in Nest Management of an Endangered Island Endemic Raptor

ABSTRACT Conservationists often face tradeoffs. We present a tradeoff that we recently faced involving nest management of the endangered Puerto Rican Sharp-shinned Hawk (Accipiter striatus venator). Given our logistical constraints, we determined we were able to either continue our ongoing efforts to induce laying of a second clutch (hereafter, double clutching) of four nests per year, or we could stop double clutching and apply insecticide for parasitic nest flies (Philornis spp.) to as many nests as possible. Observed fledging rates justified our assumptions that the fledging rate of unmanaged nests was approximately one young per nest per year, whereas nests sprayed with insecticide for flies fledged two young, and double-clutched nests fledged three young. These three young from double-clutched nests were a combination of the young from both the parent-raised and hand-raised clutches. Although double clutching is more effective than spraying nests, it is also more labor intensive. We developed a model to determine how many nests we would need to spray to produce the same number of fledglings as if we continued the ongoing double clutching regime. Modeling revealed that if we could find and spray at least eight nests, then cessation of double clutching was justified. We also performed sensitivity analysis and determined that our management conclusion was robust to uncertainty in the assumed values of fledging rates. Our modeling exercise presents an example of informed decision making in the face of uncertainty.

Anecdotal observations of ‘double clutching’ behaviour in captive Mugger crocodiles (Crocodylus palustris)

Abstract Animals modulate their behaviours in accordance with their local environment and in the process, undergo different behavioural and physiological adaptations to better survive in a given ecosystem. One such behaviour that plays an important role in survival and sustenance of a species is the breeding behaviour. In this article, we present anecdotal information on breeding strategies of Marsh or Mugger crocodiles. Mugger crocodiles mostly lay single clutch during a year and have an elongated courtship and mating period lasting for 3–4 months. However, we show anecdotal data covering a period of 2 years for a Mugger crocodile producing double clutches annually under captive conditions. The laying of multiple clutches in captive Mugger crocodiles may indicate higher nutritional status and/or breeding strategies of the females under resourceful conditions. We suggest the need for future work on understanding proximate mechanisms underlying the ‘double clutching’ behaviour of Mugger crocodiles.

МОДЕЛИРОВАНИЕ ПЕРЕКЛЮЧЕНИЯ ПЕРЕДАЧ АВТОМОБИЛЬНОЙ ТРАНСМИССИИ С ДВОЙНЫМ СЦЕПЛЕНИЕМ

A computer dynamic model of an automobile transmission with a double dry clutch, created using the "Universal Mechanism" software package, is presented. Work objective is to analyze the possibility of improving double dry clutch efficiency at various controls of compressive forces of clutch plates. The computer model contains 7 bodies: an engine crankshaft, two clutch plates, two gearbox input shafts for odd and even gears, an output shaft, a fly wheel. The simulation of gear shifting shows that pressing a clutch pedal or letting out the clutch simultaneously, cutoff time increment increases the rotational speed justification of the engine shaft and the input shaft of the actual gear, the total work of the friction forces of both clutches and does not affect the maximum value of clutch plates rotary sliding resistance. Frictional energy of the clutch when shifting gears from lower to higher is greater than when shifting gears from higher to lower. Sequential clutch on-off reduces the total frictional energy of both clutches by 1.17...1.31 times compared to simultaneous one. The model allows looking into different gearshift modes with uniform velocity or accelerated vehicle motion, optimize the gearshift strategy.

Analysis of the parameters of the double clutch drive with reduced control energy consumption

The global trend of improving vehicle and traction transmissions is associated with the use of robotic preselector gearboxes, an important component of which is the friction clutch. The review of existing designs and analysis of clutch development concepts allows determining the directions of their improvement, in particular, the improvement of dry double clutches, which is the subject of research in this paper. A significant disadvantage of existing dual-clutch designs is the use of additional special (mostly hydraulic or combined) systems for on-off friction pairs, so the structural cost and energy costs for control are increased, and the design, maintenance, and repair are complicated. The proposed design of the drive to control the original dry dual-clutch involves a lever mechanism with the use of rotary stops, which are made in the form of mobile carriages with rollers, this provides switching clutches in a short time and actually without interruption of power flow, so the acceleration dynamics of vehicles will be improved, the clutch design will be simplified and energy consumption for its control during the start and gear shifting will be reduced. The mathematical model of the proposed clutch drive on the basis of which the control mechanism operation is simulated and influence of its design parameters on operational indicators of the clutch drive, in particular, on kinematic characteristics of the drive, ranges of kinematic and power gear ratios, the power interaction of the mechanism links, the power of the actuator when each clutch is turning on. It is established that the switching of clutches requires less energy, the movement of the mechanism elements is different, and the compression force of the friction pairs when starting the first and second clutches is different. The simulation results confirm that the proposed original lever design of the clutch control mechanism is effective. The obtained results allow us to reasonably determine the parameters of a clutch, but the choice of optimal-rational parameters of its control mechanism requires further research, for which appropriate methods, search algorithms, and their software implementation have been developed.

Double-Clutch Power Shift Quality Optimization Based on Optimal Control Theory

Highlights A power shift control strategy based on torque and speed transition, which aims to deliver multiple target and multiparameter optimization of power shift control, is proposed in this study. It can effectively solve the shift power cycle. Based on minimum optimal control theory, the optimal control of shift quality during power shifting optimizes clutch terminal oil pressure, which is determined by solving the Rebecca differential matrix equation and shift characteristics based on various stages. By aiming at the multiple target and multiparameter optimization problem of the clutch control in the power shift process, the minimum optimal control principle is applied to the shift quality optimization of the power shift. Based on the minimum optimal control theory, the optimal solution of the terminal oil pressure of the clutch is determined by solving the Rebecca differential matrix equation to improve the shift quality of the power shift process. Abstract . The dual clutch of the combined transmission of a tractor with large horsepower uses a dynamic shifting process, in which only one clutch undergoes slipping friction during the shift. A power shift control strategy based on torque and speed transition, which aims to deliver multiple target and multiparameter optimization of power shift control, is proposed in this study. Based on minimum optimal control theory, the optimal control of shift quality during power shifting optimizes clutch terminal oil pressure, which is determined by solving the Rebecca differential matrix equation and shift characteristics based on various stages. In addition, the power shift simulation model of the double clutch is established. Simulation results show that the power shift control strategy based on single slip friction can effectively avoid power flow cycle, uninterruptible tractor power shift, and adaptive resistance change. The minimum optimization theory can effectively reduce the output torque fluctuation in the dynamic shift process, reduce friction work, and improve the shift impact. Keywords: Double clutch, Heavy-horsepower tractor, Minimum theory, Power shift.

PENERAPAN MODEL PEMBELAJARAN OPEN ENDED PROBLEM UNTUK MENINGKATKAN HASIL BELAJAR SISTEM KOPLING GANDA

This study aims to determine; (1) teacher activities after applying the open ended problems learning model in class XI TBSM SMKN 1 Kurun, (2) student activities after applying the open ended problems learning model in class XI TBSM SMKN 1 Kurun, (3) student responses after applying the open ended problems learning model on the double clutch system lesson, and (4) learning outcomes of class XI TBSM SMKN 1 Kurun, after following the open ended problems learning model on the double clutch system lesson. This research is descriptive quantitative, this research took the subject of class students XI TBSM SMKN 1 Kurun chosen as the subject of research. The instrument used is a test of cognitive learning outcomes, student activity sheet, teacher activity sheet, and student response questionnaires. As well as student learning outcomes related to cognitive, affective and psychomotor aspects. The results of data analysis showed that overall student activity was carried out well. The completeness of the classically tested cognitive learning outcomes of students in 13 people (92,85%) and 1 student has not yet finished (2,94%), so classically the results of student learning using open ended problems models are said to be successful

Comparative Study on the Temperature Rise of a Dry Dual Clutch Under Different Starting Conditions

A finite element model of the pressure plate and friction plate of the dry dual clutch is established to find the temperature rise of a dry double clutch in operation. Different starting conditions for the temperature of the dry dual clutch are obtained by calculating the temperature rise, and a comparative analysis of the results is conducted. Results show that the temperature rise for clutch 2 is generally higher than that for clutch 1, and the temperature rise of clutch 2 is higher than that of clutch 1, with an increasing throttle opening. A curve of the speed difference between engine and friction plates is extracted by calculating the source power of the wear of the sliding mill. It is found that the clutch speed difference of clutch 2 is generally higher than that of clutch 1 because clutch 1 follows a constant-rotation-speed control strategy at the start of grinding, leading to the temperature rise of clutch 2 being greater than that of clutch 1. A constant-engine-speed shift strategy is finally put forward.

The Vibration and Noise Study of Dry Double Clutch with Clutch Rigidity at Low Speed in Starting

By establishing engine-clutch-vehicle body nonlinear dynamic, the nonlinear dynamic behavior of DDCT is studied with Clutch rigidity. The nonlinear dynamic behavior of the chaotic and bifurcation of the vibration of the clutch system is analyzed. The stability of the system is determined by the maximum Lyapunov index method; And combined with experimental study, the clutch noise and the vibration acceleration of the gearbox during the movement of the car are tested. It shows as follows, Reducing the Clutch stiffness can effectively reduce the noise and vibration acceleration. It is also provide a theoretical basis for solving the noise problem in the starting process.

Optimization of shifting strategy for a dual clutch transmission through mathematical model

European Union legislation sets mandatory emission and fuel consumption reduction targets for new vehicles and therefore economy remains a key challenge for automotive engineers. Optimizing the transmission shift schedule for an automatic transmission with double clutch is an important part of improving fuel economy. Using simulation and optimization algorithms can ensure that a truly optimal shift schedule is implemented. The main objective of this paper focuses on study the performance of a vehicle with a dual clutch transmission (DCT), with special emphasis on optimizing the shifting schedule using optimization algorithms. In order to study and simulate the shifting strategy the dynamic model is developed based on an existing model in MATLAB Simulink software. In the first phase of the paper a detailed description of the DCT technology, its main functional components and dynamic characteristics are explored. In the second phase model development and simulation concerns the major part of this work, to find the optimal shift schedule for different engine speed and engine torque as it accelerates through the transmission gears by engaging the dual clutches. Finally, the simulation results were evaluated and presented which successfully demonstrate the performance improvement of a dual clutch transmission with an optimized shifting strategy.

The Research on Shift Rule of Double Clutch Transmission

Based on the dual clutch automatic transmission, the shift rule is studied. MTTLAB is used to establish the engine model, the transmission model and the vehicle dynamics model respectively. The input parameters are numerically analyed to analye the shift rules of the vehicle, including the best dynamic shift law and the best fuel economy shift law, the combination of shift law. According to the simulation results, we analysis three indicators which include shift speed and quality and fuel consumption.The acceleration performance of the vehicle is better than that of the economic shift rule when the dynamic shift rule is adopted. When the combined shift rule is adopted, the acceleration performance is changed from the slow to the fast. Economic shift law behave the minimum fuel consumption and the best economic performance, combined shift of the economy followed by the economic shift law, the dynamic law is the worst performance of the economy. The combined shift rule is suitable for vehicles that do not have special power requirements and fuel economy requirements for vehicles or vehicles that travel for a long period of time.

Design and simulations of dual clutch transmission for hybrid electric vehicles

Dual clutch transmissions (DCTs) refer to the double friction clutches; they are designed and operated fully automated in vehicle shift gearbox. The biggest advantage of the DCTs is the improvement of the fuel economy because the power flow from the engine to the transmission is always has a very high friction coefficient and is not interrupted. The current six-speed DCTs can provide more than 10% better fuel economy compared to the conventional six-speed automatic gearbox. This paper develops three vehicle models: conventional dual clutch transmission (DCT); conventional hybrid electric vehicle (HEV); hybrid dual clutch transition (HDCT). They are simulated on different drive-cycles. HEV and HDCT proved the superiority on fuel savings in low speeds. HDCT shows a little bit higher energy saving over HEV due to the higher efficiency of clutches to torque converters. Conclusions and recommendations for the development of DCT, HEV, and HDCT are also outlined.

Reproductive Ecology of Northern Bobwhite in North Florida

Brood habitat use and summer mortality of northern bobwhite (Colinus virginianus) chicks and adults were studied from 1984 to 1986 at Tall Timbers Research Station near Tallahassee, Florida. Adult bobwhite (n = 134) were radio-tagged and monitored throughout the breeding season. Fifty-four nests were located and 227 bobwhite chicks were monitored to determine reproductive output and brood status. Counting chicks on the roost at night provided reliable estimates of brood size reduction. Chick loss rates were 62% to 2 weeks and 71 % to 1 month posthatch. Adult mortality from 15 May to 15 October for combined years was 31 %. Seventy-one percent of females surviving to 15 October produced a brood (defined as> 1 chick surviving to 2 weeks of age). Fourteen percent of males which survived the summer incubated a nest and produced a brood. Brood locations were analyzed for vegetative structure, composition, and insect abundance and compared to random plots. An inverse correlation (P < 0.05) existed between insect abundance and brood home ranges at 2 weeks. However, there was no correlation between insect density and chick mortality (P > 0.05). Brood locations had a greater (P < 0.05) occurrence of Compositae, Gramineae, Leguminosae, Rosaceae, and shrubs than random locations. Preferred brood areas were old (>5 years), fallow fields with a scattering of shrubby thickets and a relatively open tree canopy. Two cases of double clutching occurred in which females successfully raised a brood to 1 month of age and subsequently were found incubating a second nest.

New Opportunities and Incentives for Remanufacturing by 2020's Car Service Trends

This contribution presents the results of a four-year R&D-project undertaken by a team of six scientists, expert engineers and practitioners of car service technologies. Under the guidance of the authors they explored needs and challenges of tomorrow's (2020's) car service. Three new categories of car service needs, mainly triggered by electronic and mechatronic car components, could be identified: Spare parts driven, technology trend driven and phenomena driven new service needs. Ten challenging representatives within these categories were thoroughly analyzed and new service options and approaches as solutions for 2020 and beyond could be developed. Rounding up these in five new clusters of car service technologies of tomorrow it could be shown, that in particular Remanufacturing will both receive new opportunities and incentives, because being stimulated by new service solutions, and that Remanufacturing will also considerably contribute to sustainable car life cycles of the future. The contribution will accordingly present examples from new car components such as double clutch transmission, power steering, LED-headlights, turbo chargers, driver assistant systems, carbon fiber bodyparts, common rail injectors, electro mobility components.

Design of a Modular Swift-shift Multi-speed Transmission with Double Dual Clutches for Electric Vehicles

In this paper a novel concept of modular swift-shift multi-speed transmission with double dual clutches is proposed, with its architecture, simulation and control strategies discussed in detail. Due to its modularity, the desired number of gear ratios can be readily realized by adding the appropriate number of modules. Further, in this design, both the underdrive and the overdrive modes are combined within one single gear train, which reduces the overall volume and weight significantly. Due to its modularity and compactness, this transmission is suitable for electric vehicles, especially commercial fleets of medium- and heavy-duty electric trucks. A proof-of-concept testbed was developed; its preliminary simulation analysis is reported here.

Laser structuring of printed layers on thick film ceramic substrates

The market for automatic transmissions continues to grow. In addition to what originally attracted interest to the product – enhanced driver convenience – the prospect of greater fuel efficiency is now a further factor in their favor. Continental has been offering transmission control units (TCU) since 1982, starting with those for simple three-gear conventional automatic transmissions, followed by all-wheel applications in 1985, CVT applications in 1999, truck applications in 2000, and arriving at the double clutch transmissions in widespread use today. At present Continental Business Unit Transmission is technology leader worldwide in the market for transmission controls for the full spectrum of automatic drives. Continental TCU's are divided in “Stand alone”, “Attached to” and “Integrated” TCU's. However the “Stand alone” and “Attached to” TCU's are normally equipped with standard PCB substrates. Because of the highest requirements in temperature, vibration and typical medias (aggressive Transmission oils – liquid &amp; gaseous), standard organic substrates cannot be used, ceramic substrates are typically preferred. A common technology in that case is the ceramic based thick film technology, where conductor and resistor pastes are printed on the surface of a ceramic alumina substrate by using a common screen printing process. The printed layers (Au, Ag, AgPd, AgPt) have to be dried and thermally sintered after appliance. The increasing functionality of the TCU's and the increasing requirements due to miniaturization inherently show that thickfilm technology, as applied in a standard printing process, is not possible to reach those requirements. Continental has developed a concept to realize higher miniaturization of the circuit boards. Therefore a innovative laser structuring process has been installed for the newest generations of TCU's in cooperation with a leading machine and system manufacturer. By using the laser structuring of conductor lines it allows Continental to increase the connection density by keeping the substrate size unchanged. Typical common printing pitches in thickfilm production are 300μm, however pitches of 100μm are possible by laser structuring in mass production.

건식 듀얼 클러치의 열해석 모델에 대한 연구

The stability of friction characteristics and thermal management for a dry type dual clutch transmission (DCT) are inferior to those of a wet clutch. Too high temperature resulting from frequent engagement of DCT speeds up degradation or serious wear of the pressure plate or burning of the clutch disk lining. Even though it is significantly important to estimate the temperature of a dry double clutch (DDC) in real-time, few meaningful study of the thermal model of DDC has been known yet. This study presented a thermal analytical model of lumped parameters for a DDC by analyzing its each component firstly. Then a series of experimental test was carried out on the test bench with a patented temperature telemetry system to validate the proposed thermal model. The thermal model, whose optimal parameter values were found by optimization algorithm, was also simulated on the experimental test conditions. The simulation results of DDC temperature show consistency with the experiment, which validates the proposed thermal model of DDC.