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.

A Model-Based Approach to the Estimation and Control of a Continuously Variable Transmission

2020 ◽  
Vol 28 (5) ◽  
pp. 1940-1947 ◽  
Author(s):  
William Dunham ◽  
Jinwoo Seok ◽  
Anouck Girard ◽  
Ilya Kolmanovsky ◽  
Weitian Chen ◽  
...  
Keyword(s):  
Continuously Variable Transmission ◽  
Model Based ◽  
Variable Transmission ◽  
Estimation And Control ◽  
And Control

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.

A Validated Modular Model for Hydraulic Actuation in a Pushbelt Continuously Variable Transmission

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Stan van der Meulen ◽  
Rokus van Iperen ◽  
Bram de Jager ◽  
Frans Veldpaus ◽  
Francis van der Sluis ◽  
...  
Keyword(s):  
Dynamic Characteristics ◽  
First Principles ◽  
Closed Loop ◽  
Low Complexity ◽  
High Accuracy ◽  
Continuously Variable Transmission ◽  
Design Parameters ◽  
Actuation System ◽  
Modular Model ◽  
Variable Transmission

A reduction in the fuel consumption of a passenger car with a pushbelt continuously variable transmission (CVT) can be established via optimization of the hydraulic actuation system. This requires a model of the dynamic characteristics with low complexity and high accuracy, e.g., for closed-loop control design, for closed-loop simulation, and for optimization of design parameters. The hydraulic actuation system includes a large number of hydraulic components and a model of the dynamic characteristics is scarce, which is caused by the complexity, the nonlinearity, and the necessity of a large number of physical parameters that are uncertain or unknown. In this paper, a modular model for the hydraulic actuation system on the basis of first principles is constructed and validated, which is characterized by a relatively low complexity and a reasonably high accuracy. A modular approach is pursued with respect to the first principles models of the hydraulic components, i.e., a hydraulic pump, spool valves, proportional solenoid valves, channels, and hydraulic cylinders, which reduces complexity and improves transparency. The model parameters are either directly provided, directly measured, or identified. The model of the hydraulic actuation system is composed of the models of the hydraulic components and is experimentally validated by means of measurements that are obtained from a production pushbelt CVT. Several experiment types are considered. The correspondence between the measured and simulated responses is fairly good.

scholarly journals Experimental Characteristics of Mechanical Continuously Variable Transmission with Internal Force Functions

2021 ◽  
Vol 20 (4) ◽  
pp. 310-319
Author(s):  
A. V. Yurkevich ◽  
A. V. Tereshin ◽  
V. A. Soldatkin
Keyword(s):  
Power Transmission ◽  
Rotation Frequency ◽  
Internal Force ◽  
Gear Ratio ◽  
Continuously Variable Transmission ◽  
Recording Equipment ◽  
Internal Link ◽  
Variable Transmission ◽  
New Type ◽  
Transformer Ratio

The paper proposes a new type of a mechanical continuously variable transmission with internal force functions  to upgrade the energy efficiency of a vehicle equipped with a conventional engine. The prototype of the transmission is a well-known V. F. Maltsev concurrent pulse variator in which freewheel mechanism driven members are supplemented with elastic torsions shafts. It is shown that the variator turns into a continuous transformer – a mechanical continuously variable transmission with internal force functions. There is an internal automaticity and continuity in the entire range of gear ratio changes. The configuration engineering solution is implemented in the engineering prototype. The aim of the research is experimental study of the properties and characteristics of such a mechanical continuously variable transmission. The kinematic configuration and the main structural dimensions of the engineering prototype are given. Special testing facility and measuring-and-recording equipment have been developed. A set of parameters to be recorded has been specified. The accuracy of their measurement is statistically estimated. The results of the experiments are presented in terms of output and input torque dependencies on the speed of the driven shaft. It is shown that the transmission characteristics in their dimensionless form (transformer ratio and efficiency) in the function of internal gear ratio are universal. The possibility of obtaining an infinite kinematic and significant power transmission ranges by independently changing the internal link oscillation range (level of the force function) and the rotation frequency of the drive shaft has been experimentally shown. The transmission  has high transforming and energy properties, which are higher than those of hydrodynamic gears.

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