scholarly journals Preliminary synthesis of algorithms for automatic control of automobile continuously variable transmissions with flexible links

2020 ◽  
Vol 1 (4) ◽  
pp. 25-37
Author(s):  
A.E. Yesakov ◽  
◽  
A.V. Kretov ◽  
P.A. Krasavin ◽  
◽  
...  

Variators of different operating principles and designs are of interest as components of automatic transmissions for ground transport and traction machines. At the same time, one of the most popular types of variators are the variators built on the basis of continuously variable transmissions with flexible links. The main reasons for the use of such variators in the transmissions of a number of modern passenger vehicles are, on the one hand, the emergence of flexible link designs with high durability, and, on the other hand, the widespread introduction of programmable electronic devices into automatic control systems for continuously variable transmissions. A direct consequence of the latter circumstance was the need for in-depth research aimed at synthesizing such control algorithms that would make it possible to fully use the advantages inherent in continuously variable transmissions with flexible links and minimize the operational consequences of their shortcomings. This paper makes an attempt to solve the problem of synthesizing the algorithm in a preliminary form, based on the goal of providing the vehicle with the best traction and speed properties. The presence of such an attempt will allow, having set the main parameters of a continuously variable transmission for some reason, to develop the hardware of the automatic control system. In turn, this will make it possible to synthesize a refined algorithm that takes into account the dynamics of the system, errors of meters and signal conversion devices, as well as other factors affecting work pro-cesses. When considering the described problem, various variants of the geometry of the contact surfaces of the continuously variable transmission links were taken into account and the corre-sponding mathematical apparatus were formed. The results of calculations, obtained by computer program that implements these devices, are selectively presented in the materials of the paper.

Author(s):  
I-Ming Chen ◽  
Yuan-Yao Huang ◽  
Tai-Her Yang ◽  
Tyng Liu

This study investigates the limited-slip and steering characteristics of a dual continuously variable transmission system. The dual continuously variable transmission is a unique final drive system composed of two continuously variable transmissions, with one continuously variable transmission connected to each rear wheel. In this study, a dynamic model of the dual continuously variable transmission system is derived, and models of the conventional final drive systems, i.e. the solid axle and the open differential, are used as benchmarks. In the simulations, the dual continuously variable transmission model, the solid axle model and the open differential model are applied to a vehicle dynamic model for split- μ road tests and a series of steering tests. According to the results of the split- μ road tests, the limited-slip function of a dual continuously variable transmission system is verified. The results of the steering tests show that different torque distributions for the inside wheels and the outside wheels while cornering can be controlled with different gain values of the continuously variable transmissions; for this reason, the application of the dual continuously variable transmission system as a torque-vectoring device is proposed, and a basic setting principle is presented. The results of this study establish a fundamental knowledge for developing the dual continuously variable transmission as an advanced final system for improving the vehicle dynamics.


Author(s):  
G. Mantriota

Continuously variable transmissions (CVTs) have developed notably in different applications over the past years. This is especially true in the automobile field because of advantages in terms of car handling and efficiency on urban roads. In this work an original functional solution of a power split CVT system is described. The proposed solution allows the generation of a power flow without recirculation. Kinetic characteristics of single-component devices are obtained and the power split CVT system's efficiency is determined by considering how the efficiency of the component devices changes as a function of operating conditions. The advantages for the power split CVT system are therefore shown in terms of power and efficiency in comparison with the single CVT.


2017 ◽  
Vol 7 (1) ◽  
pp. 479-484 ◽  
Author(s):  
S. S. Zumatov

AbstractMethodology of analysis of stability is expounded to the one contour systems automatic control feedback in the presence of non-linearities. The methodology is based on the use of the simplest mathematical models of the nonlinear controllable systems. Stability of program manifolds of one contour automatic control systems is investigated. The sufficient conditions of program manifold’s absolute stability of one contour automatic control systems are obtained. The Hurwitz’s angle of absolute stability was determined. The sufficient conditions of program manifold’s absolute stability of control systems by the course of plane in the mode of autopilot are obtained by means Lyapunov’s second method.


2018 ◽  
Vol 10 (1) ◽  
pp. 168781401775196
Author(s):  
Suifan Chen ◽  
Zhifeng Dong

In order to solve the oversize problem of continuously variable transmission, a rod gear pulse continuously variable transmission is designed. The kinematic mathematical models of key components are established by the matrix method and are simulated by MATLAB in a single phase, based on the analysis of basic structure and working principle of transmission. Also, the length requirements of each rod are studied, and the effect of three adjustment manners on the output-speed is simulated in the single phase. Furthermore, the simulations of the movement law of annular gear are achieved on two conditions of both different phases and different eccentricities on 8-phase. The results show that the manner of adjusting the eccentricity of eccentric wheel is the preferential selection of out-speed regulating method, and 8-phase is an optimal phase of transmission; meanwhile, for the rod gear pulse continuously variable transmission, the variable range of transmission ratio is wider and the pulsation rate is far less than the other traditional continuously variable transmissions.


2013 ◽  
Vol 135 (12) ◽  
Author(s):  
Noah D. Manring ◽  
Taha S. Al-Ghrairi ◽  
Sean D. Vermillion

This research shows that an existing rear-wheel drive vehicle may be easily retrofitted with a continuously variable-transmission for the purposes of reducing the overall fuel consumption of the automobile. The retrofit-ability of this transmission is the primary advantage that it exhibits over other continuously variable-transmissions. By retrofitting this vehicle with the transmission components that are shown in this paper, the existing vehicle transmission continues to be used with the exception of the driveshaft which is replaced by the hydraulic continuously variable-transmission itself. Using a standard model for the vehicle dynamics, this paper presents a detailed analysis for the speed ratios of all gears, and shows how to specify the size of the hydraulic pump and motor to insure a safe pressure level of operation. To illustrate the usefulness of this method, an actual transmission is designed for the 1997 Ford Ranger, and the range of adjustability for the transmission is evaluated by seeking to hold the engine speed constant for a ramped speed output of the vehicle. In conclusion, this research shows that the design methodology is valid and that only minor errors in engine speed are observed during low ground velocities for the vehicle.


Author(s):  
V. B. Derzhansky ◽  
◽  
S. V. Cherepanov ◽  
A. A. Volkov ◽  
◽  
...  

Mechanical continuously variable transmissions have high potential for torque conversion, are capable of providing significant technical and economic advantages when used in shafts of technological and other machines, this making investigations in this area to be pertinent. This paper represents a mechanical and mathematical technique, which enables to do research of dynamic processes, that occur in functioning of mechanical continuously variable transmission with a resilient member and free-wheel mechanism, making it possible to transmit torque to a driven shaft only in the same direction. The objective of this paper is to work out a mathematical model of the mechanical system, which determines dynamic force of transmission elements. Computational model of transmission is shown, in obedience to which there was built a mathematical model based on Lagrange equation of second kind with undetermined multipliers. A set of assumptions was made on working out the dynamic system mathematical model. In particular, possibility of excitation of resonant modes in a resilient member was not considered. Moreover, nonlinearity of free-wheel mechanisms was not considered as well as hysteresis losses of energy in on-off use cycle and significant capacity costs in disconnected machinery. In future it is necessary to carry out experimental investigations in order to make transmission dynamics more exact. By the results of simulation modeling regularities were obtained which determine dynamic moments on transmission elements. The results of the investigation may be used for making an output characteristic of transmission, its adaptation with the motor and forecasting of operational features of shafts of different technological equipment.


2018 ◽  
Vol 19 (6) ◽  
pp. 447-451
Author(s):  
Jarosław Goszczak ◽  
Bartosz Radzymiński

Paper concerned the Continuously Variable Transmission (CVT). The comparison of the engine’s work conditions with conventional manual transmission and CVT’s is presented. Also, a short historical track is included. Furthermore, a production data with the forecast is presented for different parts of the World. Various current solutions of continuous ratio change are mentioned with the more detailed description of the most popular design used in passenger cars. Technological challenges and possibilities of further transmission improvement are included.


Author(s):  
R E Dorey

There is strong interest in continuously variable transmission systems of vehicle and industrial drives. They offer the potential for improved matching between the prime mover and load, together with possibilities for increased performance and more energy efficient operation. Many continuously variable transmissions have been proposed over the years, but few have received the serious consideration necessary to bring them to market prominence. This paper is concerned with the evaluation of a device that has reached a prototype stage, but would need significant investment of resources to advance its development.


Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3369 ◽  
Author(s):  
Francesco Bottiglione ◽  
Giacomo Mantriota ◽  
Marco Valle

In a wind turbine, if a continuously variable transmission is placed between the turbine rotor and the generator, the speed ratio can be tuned to match the variable rotor speed to the constant speed of the electric generator, thus eliminating the need to adapt the frequency to the grid. In this paper, power-split hydrostatic transmission (PS-HTS) architecture is proposed as a suitable continuously variable transmission for application to wind turbine systems. The performance of PS-HTS is modelled and compared with that of previously proposed architectures in which the hydrostatic transmission is placed in-line with traditional drives (in-line HTS). It is shown here that the PS-HTS can improve the annual energy production of a 250 kW rated power wind turbine of about 10–11% by employing a hydrostatic transmission with one-seventh the size of the one requested by in-line HTS architecture.


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