scholarly journals INCREASING THE COMFORTABILITY OF THE VEHICLE DURING ACCELERATION BY IMPROVING THE DESIGN AND CONTROL METHODS OF THE MOTOR-TRANSMISSION UNIT

2021 ◽  
pp. 81-85
Author(s):  
Mikhail Podrigalo ◽  
Volodymir Krasnokutskyi ◽  
Olexander Tkachenko
Keyword(s):  
High Speed ◽  
Aerodynamic Resistance ◽  
Gear Ratio ◽  
Continuously Variable Transmission ◽  
Engine Torque ◽  
Transmission Unit ◽  
Variable Transmission ◽  
Acceleration And Deceleration ◽  
Speed Mode ◽  
Engine Power

The derivative of acceleration with respect to time is used to evaluate and ensure driving comfort during acceleration and deceleration. Frequent and rapid changes in acceleration means frequent and rapid deformation, which can lead to the destruction of the load. The article proposes to minimize the amount of acceleration due to the rational choice of transmission ratios in intermediate gears and the law of changing the engine torque. The use of continuously variable transmissions allows you to solve the problem by choosing a rational law for changing the gear ratio of the transmission. The method of selection at the stage of car design of the maximum effective engine power and transmission ratio in top gear is proposed, taking into account the improved formula for calculating the aerodynamic resistance to motion. The required laws of change in the efficiency of the torque and engine power have been determined. The use of a continuously variable transmission allows the engine to operate at a constant high-speed mode and provides control over the acceleration of the car by changing the fuel supply. It is determined that the engine power expended on the movement with the adjustment of the acceleration of the car will be less than with unregulated acceleration if the exponent at the speed of the car, obtained experimentally, is less than one. Keywords: car; comfort; continuously variable transmission; motor-transmission unit; power; overclocking; aerodynamic resistance; gear ratio

Іmprovement of driving-speed properties improvement of the method for selecting the parameters of the motor-transmission unit car

2021 ◽  
Vol 13 (1) ◽  
pp. 111-117
Author(s):  
Mikhail Podrigalo ◽  
◽  
Volodymyr Krasnokutskyi ◽  
Vitaliy Kashkanov ◽  
Olexander Tkachenko ◽  
...  
Keyword(s):  
Aerodynamic Drag ◽  
Dynamic Properties ◽  
Aerodynamic Characteristics ◽  
Gear Ratio ◽  
Design Stage ◽  
Transmission Unit ◽  
Air Resistance ◽  
Design Speed ◽  
Maximum Design ◽  
Engine Power

Aerodynamic characteristics have a major impact on the energy efficiency and traction and speed properties of the vehicle. In this article, based on previous studies of the aerodynamic characteristics of various car models, we propose an improved method for selecting engine and transmission parameters at the design stage. The aim of the study is to improve the dynamic properties of the car by improving the method of selecting the main parameters of the engine-transmission unit by refining the calculation of aerodynamic drag. To achieve it, the following tasks must be solved: to specify the method of selecting the maximum effective engine power; to specify a technique of definition of the maximum constructive speed of the car; to develop a technique for selecting gear ratios. The aerodynamic resistance to the movement of the vehicle is determined by the frontal coefficient of the specified resistance, the density of the air, the area of the frontal resistance and the speed of the vehicle. It is known from classical works on the aerodynamics of a car that in the range of vehicle speeds from 20 m / s to 80 m / s, taking the law of squares when assessing the force of air resistance, it is necessary to change the coefficient of frontal aerodynamic drag depending on the speed of the car. However, when carrying out calculations, this coefficient is taken constant, which leads to obtaining large values of the air resistance force at high speeds and lower at low speeds. There are two possible ways to improve the dynamic properties and energy efficiency of the car during its modernization (increasing the maximum design speed of the car by reducing the gear ratio in higher gear; reducing the maximum efficiency of the engine while maintaining the previous gear ratio in higher gear). As a result of the study, the method of selection (maximum effective engine power; maximum design speed of the car; gear ratios) at the design stage of the parameters of the motor-transmission unit of the car has been improved.

Optimization of Hydraulic Pressure for Continuously Variable Transmission

2011 ◽  
Vol 317-319 ◽  
pp. 529-532
Author(s):  
Kei Lin Kuo
Keyword(s):  
Torque Converter ◽  
Transmission Efficiency ◽  
Gear Ratio ◽  
Continuously Variable Transmission ◽  
Hydraulic Pressure ◽  
Primary Input ◽  
Input Shaft ◽  
Variable Transmission ◽  
Labview Program ◽  
Set Up

Compared to conventional transmission layouts, Active continuously variable transmission (CVT) provides smoother gear shifting and gear ratio in smaller increments, and is, therefore, more accommodating the needs of both the driver and passengers. A few notable improvements are enhanced passenger comfort, higher transmission efficiency, and improved acceleration. Incorporating all of the above qualities has become a major developmental focus for the automotive industry, and the potential for improvement warrants further investigation. A CVT controls the gear ratio by changing the diameters of the primary (input) and the secondary (output) pulleys by adjusting the hydraulic pressure applied to each using valves. Hydraulic pressure in the channel is developed using a basic pump connected to the input shaft. Excess pressure produced at higher speed is wasted. This study aims to minimize this hydraulic pressure without affecting the transmission’s performance, in order to conserve energy. A user interface was set up and the CVT’s torque converter was modified such that the inner and outer shafts could be operated independently, allowing for full control of hydraulic pressure .This experiment successfully achieved, via a custom LabVIEW program, its goal of controlling the gear ratio between the primary and secondary pulleys whilst operating at lower pressures to those specified by the manufacturer. This proves that it is possible to fully control the CVT whilst operating at a reduced hydraulic pressure.

Methods for Controlling a Wind Turbine System With a Continuously Variable Transmission in Region 2

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Andrew H. Rex ◽  
Kathryn E. Johnson
Keyword(s):  
Wind Turbine ◽  
Gear Ratio ◽  
Continuously Variable Transmission ◽  
Variable Speed ◽  
Wind Turbine System ◽  
Variable Speed Wind Turbine ◽  
Fast Wind ◽  
Variable Transmission ◽  
Integral Controller ◽  
Proportional Integral Controller

Variable speed operation enables wind turbine systems to increase their aerodynamic efficiency and reduce fatigue loads. An alternative to the current electrically based variable speed technologies is the continuously variable transmission (CVT). A CVT is a transmission whose gear ratio can be adjusted to take on an infinite number of settings within the range between its upper and lower limits. CVT research in wind turbine applications predicts an improvement in output power and torque loads compared with fixed-speed machines. Also, a reduction in the harmonic content of the currents is anticipated by eliminating the power electronics. This paper develops a model that combines a CVT model with the FAST wind turbine simulator for simulating the system’s performance in MATLAB/SIMULINK. This model is useful for control development for a variable-speed wind turbine using a CVT. The wind turbine with CVT is simulated using two controllers: a proportional-integral controller and a nonlinear torque controller of the type commonly used in the wind industry.

Study on Optimal Load for Hydraulic Control System of Continuously Variable Transmission

2012 ◽  
Vol 516-517 ◽  
pp. 665-668
Author(s):  
Kei Lin Kuo
Keyword(s):  
Monitoring Program ◽  
Transmission Efficiency ◽  
Gear Ratio ◽  
Visual Programming ◽  
Continuously Variable Transmission ◽  
Operating Conditions ◽  
Hydraulic Pressure ◽  
Hydraulic Control ◽  
Main Research ◽  
Variable Transmission

In recent years, the main research focus for vehicle transmission systems has been the development of the Continuously Variable Transmission (CVT). CVTs can provide passengers with greater comfort, reduce energy consumption, and offer better transmission efficiency. CVT systems achieve the desired gear ratio by adjusting the hydraulic pressure on the rear and front pulleys using a solenoid valve. Our study aims to increase the efficiency of an existing CVT system, without reducing its performance. In this study have modified the CVT so that we can independently control the external and internal axes electronically. The speed of the hydraulic pump in the gearbox is not affected by the engine speed. In this way, In this study can achieve the lowest possible hydraulic pressure. In our study, In this study use the visual programming language LabVIEW as the human-machine interface for the monitoring program. In addition, a data acquisition system is used to collect experimental parameters, record data in real time, and perform data consolidation. Our system uses varying loads in order to evaluate the improvement in transmission efficiency over many operating conditions. Through the use of solenoids valves acting together, the pipeline hydraulic pressure can be varied. The widths of the front and rear pulleys are thus changed to achieve the goal of continuous variation. Under different loads, the relationships between the measured efficiency and the hydraulic pressure on the rear and front pulleys are used to verify and confirm the increase in efficiency achieved by controlling the hydraulic pressure.

Dynamics Analysis and Control of a Holonomic Vehicle With a Continuously Variable Transmission

2000 ◽  
Vol 124 (1) ◽  
pp. 118-126 ◽  
Author(s):  
Karim A. Tahboub ◽  
Harry H. Asada
Keyword(s):  
Dynamic Characteristics ◽  
Impedance Matching ◽  
Gear Ratio ◽  
Continuously Variable Transmission ◽  
Friction Compensation ◽  
Vehicle Stability ◽  
Dynamics Analysis ◽  
Dc Motors ◽  
Variable Transmission ◽  
And Control

This paper presents kinematic and dynamic analysis of a holonomic vehicle with continuously-variable transmission. Four ball wheels, independently actuated by DC motors, enable for moving the vehicle in any direction within the plane and rotating it around its center. The angle between the two beams holding the balls can be changed to alter the gear ratio and other dynamic characteristics of the vehicle. This feature is exploited in augmenting the vehicle stability, optimizing output power, selecting an appropriate gear ratio, and in impedance matching. A simple adaptive friction-compensation-based controller is proposed to handle the complex friction properties.

scholarly journals Analysis of continuously variable transmission for flywheel energy storage systems in vehicular application

2014 ◽  
Vol 229 (2) ◽  
pp. 273-290 ◽  
Author(s):  
Aditya Dhand ◽  
Keith Pullen
Keyword(s):  
Energy Storage ◽  
High Speed ◽  
Power Flow ◽  
Mechanical Energy ◽  
Storage System ◽  
Continuously Variable Transmission ◽  
Speed Ratio ◽  
Flywheel Energy Storage ◽  
Energy Storage Devices ◽  
Variable Transmission

Energy storage devices are an essential part of hybrid and electric vehicles. The most commonly used ones are batteries, ultra capacitors and high speed flywheels. Among these, the flywheel is the only device that keeps the energy stored in the same form as the moving vehicle, i.e. mechanical energy. In order to connect the flywheel with the vehicle drive line, a suitable means is needed which would allow the flywheel to vary its speed continuously, in other words a continuously variable transmission (CVT) is needed. To improve the efficiency and speed ratio range of the variators, a power spilt CVT (PSCVT) can be employed. This paper discusses the kinematics of PSCVT used to connect the flywheel to the driveline. A methodology describing the characteristic equations of speed ratio, power flow and efficiency of the PSCVT for various types including power recirculating and multi regime in both directions of power flow has been presented. An example of a PSCVT for a flywheel energy storage system (FESS) is computed using the derived equations and the results compared.

scholarly journals Optimization Transmission Efficiency with Driver Intention for Automotive Continuously Variable Transmission under Slip Mode

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Ling Han ◽  
Hui Zhang ◽  
Ruoyu Fang ◽  
Hongxiang Liu
Keyword(s):  
Model Predictive Control ◽  
Predictive Control ◽  
Combustion Engine ◽  
Bottom Layer ◽  
Transmission Efficiency ◽  
Continuously Variable Transmission ◽  
Integrated System ◽  
Engine Torque ◽  
Variable Transmission ◽  
Fuzzy Control Strategy

AbstractThis study proposes and experimentally validates an optimal integrated system to control the automotive continuously variable transmission (CVT) by Model Predictive Control (MPC) to achieve its expected transmission efficiency range. The control system framework consists of top and bottom layers. In the top layer, a driving intention recognition system is designed on the basis of fuzzy control strategy to determine the relationship between the driver intention and CVT target ratio at the corresponding time. In the bottom layer, a new slip state dynamic equation is obtained considering slip characteristics and its related constraints, and a clamping force bench is established. Innovatively, a joint controller based on model predictive control (MPC) is designed taking internal combustion engine torque and slip between the metal belt and pulley as optimization dual targets. A cycle is attained by solving the optimization target to achieve optimum engine torque and the input slip in real-time. Moreover, the new controller provides good robustness. Finally, performance is tested by actual CVT vehicles. Results show that compared with traditional control, the proposed control improves vehicle transmission efficiency by approximately 9.12%–9.35% with high accuracy.

Sign in / Sign up

Export Citation Format

Share Document