scholarly journals Intelligent Multiobjective Slip and Speed Ratio Control of a Novel Dual-Belt Continuously Variable Transmission for Automobiles

2014 ◽  
Vol 2014 ◽  
pp. 1-17
Author(s):  
Zhengchao Xie ◽  
Pak Kin Wong ◽  
Yueqiao Chen ◽  
Ka In Wong
Keyword(s):  
Analytical Model ◽  
Fuzzy Controller ◽  
Transmission Efficiency ◽  
Continuously Variable Transmission ◽  
Speed Ratio ◽  
Rule Base ◽  
Passenger Cars ◽  
Variable Transmission ◽  
Torque Capacity ◽  
Low Torque

Van Doorne’s continuously variable transmission (CVT) is the most popular CVT design for automotive transmission, but it is only applicable to low-power passenger cars because of its low torque capacity. To overcome this limitation of traditional single-belt CVT, a novel dual-belt Van Doorne’s CVT (DBVCVT) system, which is applicable to heavy-duty vehicles, has been previously proposed by the authors. This paper, based on the published analytical model and test rig of DBVCVT, further proposes an intelligent multiobjective fuzzy controller for slip and speed ratio control of DBVCVT. The controller aims to safely control the clamping forces of both the primary and the secondary pulleys in order to improve the transmission efficiency, achieve the accurate speed ratio, and avoid the belt slip under different engine loads and vehicle speeds. The slip, speed ratio, and transmission efficiency dynamics of DBVCVT are firstly analyzed and modeled in this paper. With the aid of a flexible objective function, the analytical model, and fuzzy logic, a Pareto rule base for fuzzy controller is developed for multiobjective DBVCVT control. Experimental results show that the proposed controller for slip and speed ratio regulation of DBVCVT is effective and performs well under different user-defined weights.

Development of a Novel Dual-Belt Van Doorne's Continuously Variable Transmission for Automobiles — A Preliminary Study

2018 ◽  
Vol 18 (02) ◽  
pp. 1850016 ◽  
Author(s):  
Pak Kin Wong ◽  
Zhengchao Xie ◽  
Yueqiao Chen ◽  
Lap Mou Tam
Keyword(s):  
Analytical Model ◽  
Power Efficiency ◽  
Continuously Variable Transmission ◽  
Heavy Duty ◽  
Passenger Cars ◽  
Variable Transmission ◽  
Torque Capacity ◽  
Preliminary Study ◽  
Simulation Results ◽  
Low Torque

The continuously variable transmission (CVT) is one of the prevailing automotive transmissions. Nowadays, the most popular design is Van Doorne's CVT with single metal pushing V-belt. However, it is only applicable to low-power passenger cars because of its low torque capacity. To overcome this limitation of traditional single-belt Van Doorne's CVT, this research proposes a novel parallel Van Doorne's dual-belt CVT system which can be applied to heavy-duty vehicles. As the first attempt, an analytical model for both torque capacity and power efficiency based on effective radii instead of traditional working radii for the single-belt CVT is developed for this novel CVT system, and this newly developed model is experimentally validated. Evaluation result reveals that the new analytical model based on effective radii is more accurate than that based on working radii. Experimental and simulation results show that the proposed dual-belt CVT system can greatly improve the torque capacity as compared with the single-belt CVT. Moreover, the newly proposed analytical model can provide a foundation for further study of multi-belt CVTs.

scholarly journals An Experimental Study on Dynamics of a Novel Dual-Belt Continuous Variable Transmission Based on a Newly Developed Test Rig

2015 ◽  
Vol 2015 ◽  
pp. 1-23 ◽  
Author(s):  
Pak Kin Wong ◽  
Zhengchao Xie ◽  
Yueqiao Chen
Keyword(s):  
Experimental Study ◽  
Analytical Model ◽  
Continuous Variable ◽  
Transmission Efficiency ◽  
Speed Ratio ◽  
Test Rig ◽  
Light Load ◽  
Continuous Variable Transmission ◽  
Continuously Variable Transmissions ◽  
Variable Transmission

A novel dual-belt Van Doorne’s continuous variable transmission (DBVCVT) system, which is applicable to heavy-duty vehicles, has been previously proposed by the authors in order to improve the low torque capacity of traditional single-belt CVT. This DBVCVT is a novel design among continuously variable transmissions and is necessary to be prototyped for experimental study, and the analytical dynamic model for this DBVCVT also needs to be experimentally validated. So, this work originally fabricated a prototype of DBVCVT and integrates this prototype to a light-load hardware-in-the-loop test rig by replacing the engine and load equipment with the AC motor and magnetic powder dynamometer. Moreover, with the use of this newly developed test rig, this work implements the experimental study of this DBVCVT for the first time. The comparison of experimental and simulation results validates the previously proposed analytical model for DBVCVT, and some basic characteristics of the DBVCVT in terms of the reliability, speed ratio, and transmission efficiency are also experimentally studied. In all, this developed test rig with the analytical model lays the foundation for further study on this novel DBVCVT.

A New Self-Adjusting CVT Configuration Using Compliant Mechanisms

2002 ◽  
Author(s):  
Myles T. Christensen ◽  
Spencer P. Magleby ◽  
Larry L. Howell ◽  
Robert H. Todd ◽  
Clint Mortensen
Keyword(s):  
Analytical Model ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Continuously Variable Transmission ◽  
Special Design ◽  
Design Considerations ◽  
Variable Transmission

This paper introduces a new configuration of a Continuously Variable Transmission (CVT) that is self-adjusting and designed as a compliant mechanism. This new configuration is called the Pivot-Arm CVT. The criteria for classification as a Pivot-Arm CVT is discussed. An analytical model describing the performance of the Pivot-Arm CVT is developed. Special design considerations which may be useful in implementing Pivot-Arm CVTs are introduced and explained. The Pivot-Arm CVT model is validated through controlled testing of two Pivot-Arm CVT prototypes.

scholarly journals An Evaluation Method of Mode Switching Quality for Double-Belt Continuously Variable Transmission

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Lanchun Zhang ◽  
Zhongwei Zhu ◽  
Bin Huang ◽  
Tianbo Wang
Keyword(s):  
Evaluation Method ◽  
Evaluation Model ◽  
Subjective Evaluation ◽  
Objective Evaluation ◽  
Transmission Efficiency ◽  
Continuously Variable Transmission ◽  
Mode Switching ◽  
Evaluation Indexes ◽  
Variable Transmission ◽  
Driver’S Intention

In order to improve the transmission efficiency and carrying capacity of conventional single-belt continuously variable transmission (CVT), one new type of dual-belt CVT is proposed in this paper. Under the situation that this new dual-belt CVT should be switched between single- and dual-belt modes frequently according to driver’s intention and road conditions, so five objective evaluation indexes of mode switching quality for the dual-belt CVT are proposed, considering the aspects of vehicle power, comfort, and transmission durability comprehensively. Then, the objective evaluation model of mode switching quality is established by the BP neural network optimized by the genetic algorithm. It is found that the prediction results are consistent with the subjective evaluation. After analyzing the influence of the selected five evaluation indexes on the prediction results, it is obvious that these five evaluation indexes of mode switching quality for dual-belt CVT are reasonable.

scholarly journals Research on Transmission Characteristics of Hydromechanical Continuously Variable Transmission of Tractor

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Junyan Wang ◽  
Changgao Xia ◽  
Xin Fan ◽  
Junyu Cai
Keyword(s):  
Power Flow ◽  
Flow Direction ◽  
Transmission Efficiency ◽  
Continuously Variable Transmission ◽  
Simulation Software ◽  
Transmission Scheme ◽  
Compact Structure ◽  
Theoretical Derivation ◽  
Speed Regulation ◽  
Variable Transmission

This paper proposes a new transmission scheme of hydromechanical continuously variable transmission (HMCVT) for tractors. The HMCVT has 4 working ranges in each of the front and rear directions. The speed characteristic and the torque characteristic of HMCVT are theoretically derived. On the basis of HMCVT power flow direction, the Крейнeс formula is used to calculate the transmission efficiency. Then, the image analysis method is used to study the influence of parameters on the transmission efficiency of HMCVT, and the main influencing factors are found. The results of theoretical derivation demonstrate that, by coordinating control of the HST displacement ratio and the engagement conditions of shifting clutches, the stepless speed regulation of HMCVT at the tractor speed of 0–50 km/h can be realized. The proposed HMCVT has the ability to continuously transmit and change torque over all working ranges. The overall transmission efficiency of HMCVT is at a high level. To verify the theoretical derivation, Amesim simulation software is used for the modeling and simulation of HMCVT. The simulation results are consistent with the theoretical analysis results. Therefore, the HMCVT proposed in this paper has the advantages of compact structure and high transmission efficiency, and it is suitable for matching tractors.

scholarly journals Real-Time Control Strategy for CVT-Based Hybrid Electric Vehicles Considering Drivability Constraints

2019 ◽  
Vol 9 (10) ◽  
pp. 2074 ◽  
Author(s):  
Hangyang Li ◽  
Yunshan Zhou ◽  
Huanjian Xiong ◽  
Bing Fu ◽  
Zhiliang Huang
Keyword(s):  
Real Time ◽  
Fuel Consumption ◽  
Electric Vehicles ◽  
Hybrid Electric Vehicles ◽  
Continuously Variable Transmission ◽  
Speed Ratio ◽  
Driving Pattern ◽  
Variable Transmission ◽  
Equivalent Factor ◽  
Hybrid Electric

The energy management strategy has a great influence on the fuel economy of hybrid electric vehicles, and the equivalent consumption minimization strategy (ECMS) has proved to be a useful tool for the real-time optimal control of Hybrid Electric Vehicles (HEVs). However, the adaptation of the equivalent factor poses a major challenge in order to obtain optimal fuel consumption as well as robustness to varying driving cycles. In this paper, an adaptive-ECMS based on driving pattern recognition (DPR) is established for hybrid electric vehicles with continuously variable transmission. The learning vector quantization (LVQ) neural network model was adopted for the on-line DPR algorithm. The influence of the battery state of charge (SOC) on the optimal equivalent factor was studied under different driving patterns. On this basis, a method of adaptation of the equivalent factor was proposed by considering the type of driving pattern and the battery SOC. Besides that, in order to enhance drivability, penalty terms were introduced to constrain frequent engine on/off events and large variations of the continuously variable transmission (CVT) speed ratio. Simulation results showed that the proposed method efficiently improved the equivalent fuel consumption with charge-sustaining operations and also took into account driving comfort.

Ratio Control Strategy for an Electromechanical Continuously Variable Transmission Based on Engine Models

2011 ◽  
Vol 291-294 ◽  
pp. 2861-2865 ◽  
Author(s):  
Qiang Jiang ◽  
Hong Yi Liu ◽  
Jian Jun Hao ◽  
Yue Cheng
Keyword(s):  
Pid Control ◽  
Control Algorithm ◽  
Continuously Variable Transmission ◽  
Speed Ratio ◽  
Vehicle Speed ◽  
Working Models ◽  
Special Character ◽  
Variable Transmission ◽  
New Type ◽  
Dynamical Coupling

Electromechanical control CVT (EM-CVT) is a new type of continuously variable transmission, and its ratio quality is an important parameter validated the performance of vehicle. In order to study the dynamical coupling technology between EM-CVT and engine under the running state of vehicle, the special character of two working models is obtained by engine experiment; according to the principle of the EM-CVT, the relation between vehicle speed and ration is theoretically analyzed. Based on the basic theory of PID control, the improved PID control algorithm is proposed for the speed ratio control of the EM-CVT, and experimental verification is made. The experimental results show that there is a significant effect on the system with this algorithm.

Multi-Range Hydro-Mechanical Continuously Variable Transmission of Tractor

2009 ◽  
Vol 628-629 ◽  
pp. 167-172
Author(s):  
L.Y. Xu ◽  
Zhi Li Zhou ◽  
M.Z. Zhang ◽  
Y. Niu
Keyword(s):  
High Efficiency ◽  
Planetary Gear ◽  
Transmission Efficiency ◽  
Continuously Variable Transmission ◽  
Speed Range ◽  
Displacement Pump ◽  
Variable Transmission ◽  
Variable Displacement ◽  
Wide Speed Range ◽  
Ratio Transmission

In this paper, to improve the transmission ratio discontinuity problem during the gear shift process in the multi-gear fixed step ratio transmission of the tractors, a hydro-mechanical continuously variable transmission (HMCVT) for tractors is developed, which is composed of a single planetary gear differential train, a hydraulic transmission system consisted of the variable displacement pump (PV) and the fixed displacement motor (MF) and a multi-gear fixed step ratio transmission. Its stepless-speed-regulating characteristic, smooth range shifting condition and transmission efficiency are analyzed. The analytical results show that the tractors assembled with HMCVT can gain wide speed range and high transmission efficiency. There are eight high efficiency pure mechanical gears in the whole speed range, which is benefit to improve power and economic capabilities of vehicles.

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