Analysis of Dynamic Characteristics of Automatic Transmission Shifting Control

2014 ◽  
Vol 643 ◽  
pp. 42-47 ◽  
Author(s):  
Yan Xiao Fu ◽  
Liang Yi Cui ◽  
Xiang Yang Xu ◽  
Peng Dong

Basing on the fact that requirements for shift quality in automatic transmissions have been increasing rapidly necessitates the establishment of a suitable shifting control strategy in order to facilitate smoothness of different processes, this paper introduces a simulation model of an 8-speed automatic transmission for front-drive vehicles with respect to detailed shifting strategies and relative parameters. The transmitted torque of the oncoming shift elements before synchronization point can be reduced by an impact function in order to damp the impact and thus make the gear shifting process more smooth. This paper makes a systematic introduction of the structure of 8AT, theoretical basis of control strategy, the establishment of the simulation model and the comparison between test results and simulation results. The conclusion shows that with an accurate dynamic model, simulation results and test results are neighborhood data, the simulation model can be used to help realizing the ultimate goal of better shift quality with higher efficiency, lower shift loads and improved shifting comfort.

2013 ◽  
Vol 372 ◽  
pp. 538-542
Author(s):  
Guo Zhong Jia ◽  
Xin Ping Wu ◽  
Zhen Hua Jia

According to the special structure of DCT, the control strategy of launch with two clutches has been proposed to share the friction work and extend the life of both clutches. The dynamic model of launch with two clutches and the clutch control model have been built. the control strategies of both clutches have been proposed respectively according to the requirement of the different driver intention and the limitation of the impact of vehicle. The simulation model of launch with two clutches has been built using the Matlab/Simulink platform, and the simulation has been carried out. The Simulation results show that the balance of friction work based on this launch strategy with two clutches has been validated.


2016 ◽  
Vol 835 ◽  
pp. 687-692 ◽  
Author(s):  
Lin Yue Zhang ◽  
Yao Fu ◽  
Xing Zhong Li

Shift process of automatic transmission is divided into torque phases and inertia phase, and the control principle of clutch to clutch shift is studied with the lever method. Then, inertia phase engine and transmission integrated control principle and entire shift process engine and transmission integrated control principle are respectively studied with taking power on up shift as study example and taking the transmission output torque fluctuations during shifting minimum as control target. Simulation results are compared to the results of power on up shift without engine and transmission integrated control, and it is proved that the transmission output torque overshoot peak with inertia phase engine and transmission integrated control strategy is decreased significantly and shifting jerks are reduced. Shift quality is improved significantly.


2016 ◽  
Vol 30 (02) ◽  
pp. 1550268 ◽  
Author(s):  
Jinwei Shi ◽  
Xingbai Luo ◽  
Jinming Li ◽  
Jianwei Jiang

To analyze the process of jet penetration in water medium quantitatively, the properties of jet penetration spaced target with water interlayer were studied through test and numerical simulation. Two theoretical models of jet penetration in water were proposed. The theoretical model 1 was established considering the impact of the shock wave, combined with the shock equation Rankine–Hugoniot and the virtual origin calculation method. The theoretical model 2 was obtained by fitting theoretical analysis and numerical simulation results. The effectiveness and universality of the two theoretical models were compared through the numerical simulation results. Both the models can reflect the relationship between the penetration velocity and the penetration distance in water well, and both the deviation and stability of theoretical model 1 are better than 2, the lower penetration velocity, and the larger deviation of the theoretical model 2. Therefore, the theoretical model 1 can reflect the properties of jet penetration in water effectively, and provide the reference of model simulation and theoretical research.


2015 ◽  
Vol 789-790 ◽  
pp. 957-961
Author(s):  
Syabillah Sulaiman ◽  
Pakharuddin Mohd Samin ◽  
Hishamuddin Jamaluddin ◽  
Roslan Abd Rahman ◽  
Saiful Anuar Abu Bakar

This paper proposed semi active controller scheme for magnetorheological (MR) damper of a heavy vehicle suspension known as Tire Force Control (TFC). A reported algorithm in the literature to reduce tire force is Groundhook (GRD). Thus, the objective of this paper is to investigate the effectiveness of the proposed TFC algorithm compared to GRD. These algorithms are applied to a quarter heavy vehicle models, where the objective of the proposed controller is to reduce unsprung force (tire force). The simulation model was developed and simulated using MATLAB Simulink software. The use of semi active MR damper using TFC is analytically studied. Ride test was conducted at three different speeds and three bump heights, and the simulation results of TFC and GRD are compared and analysed. The results showed that the proposed controller is able to reduced tire force significantly compared to GRD control strategy.


2019 ◽  
Vol 46 (11) ◽  
pp. 1001-1009 ◽  
Author(s):  
Villu Kukk ◽  
Annegrete Külaots ◽  
Jaan Kers ◽  
Targo Kalamees

The objective of this study was to determine the maximum allowable initial moisture content (MC) for cross-laminated timber (CLT) walls having both exterior and interior thermal insulation. A laboratory test was conducted, for which four test walls with two different insulation solutions and two different MCs were built. Based on the test results, a simulation model was configured and simulations using the model were completed. The simulation results determined that the maximum allowable initial MC of the CLT panels was 17% for walls insulated additionally from inside with mineral wool and 15% for CLT wall assemblies insulated with polyisocyanurate (PIR). Based on these results, it was concluded that the allowable MC ranges between 8% and 16% for construction timber, and therefore, using a PIR board as interior insulation for CLT walls should be undertaken with caution given the very small margin for error in MC.


2017 ◽  
Vol 22 ◽  
pp. 00081
Author(s):  
Marcin Klimczak ◽  
Jacek Bojarski ◽  
Piotr Ziembicki ◽  
Piotr Kęskiewicz

2016 ◽  
Vol 2016 ◽  
pp. 1-10
Author(s):  
Fei Yao ◽  
Guangyu Chen ◽  
Jianhong Su

To identify shield grouting quality based on impact echo method, an impact echo test of segment-grouting (SG) test piece was carried out to explore effect of acoustic impedance of grouting layers and grouting defects on impact echo law. A finite element numerical simulation on the impact echo process was implemented. Test results and simulation results were compared. Results demonstrated that, under some working conditions, finite element simulation results and test results both agree with theoretical values. The acoustic impedance ratio of SG material influenced the echo characteristics significantly. But thickness frequency could not be detected under some working conditions because the reflected energy is weak. Frequency feature under grouting defects was more complicated than that under no grouting defects.


Author(s):  
Takatoshi Asada ◽  
Yosuke Hirata ◽  
Susumu Naito ◽  
Mikio Izumi ◽  
Yukio Yoshimura

In alpha radioactivity measurement using ionized air transportation (AMAT), conversion from ion currents to radioactivity accurate is required. An ion transport simulation provides ways of complementarily determining conversion factors. We have developed an ion transport simulation model. Simulation results were compared with experiments with air speeds, faster than 1 m/s, achieving good agreement. In a practical AMAT apparatus, the air-flow at the alpha source may be slower than 1 m/s, and ion loss is likely to be large. Reinforcement of the ion transport model to cover the lower air speed region is effective. Ions are generated by an alpha particle in a very thin column. Since the ion density at this temporal stage is high, the recombination loss, proportional to the square of ion density, is dominant within a few milli-seconds. The spatial and temporal scales of this columnar recombination are too small for CFD simulation. We solve an ion transport equation during the period of columnar recombination with diffusion and recombination terms and incorporated the relation between ion loss and turbulent parameters into CFD. Using this model, simulations have been done for various air speeds and targets. Those for simulation results agree with experiments, showing improvement of simulation accuracy.


Author(s):  
Chunhao J. Lee ◽  
Kumar Hebbale ◽  
Shushan Bai ◽  
Farzad Samie

Friction Launch transmissions use a wet multi-plate clutch to replace the torque converter in an automatic transmission. The main benefit of this technology is fuel economy improvement as a result of eliminating the losses in the torque converter. By using one of the range clutches inside the transmission instead of an input clutch in place of the converter, the benefits of this integrated friction launch technology, such as reduction in mass, packaging, and cost, can be enhanced. The availability of new automatic transmissions with higher number of speeds and wider overall ratio spreads makes this technology more viable than ever before. This project focuses on control issues with the friction launch clutch which include developing robust control algorithms for launch and creep, and providing damping to the driveline, when required, and ensuring acceptable vehicle drivability. This paper describes in detail the development of vehicle launch control algorithms. Vehicle test data is presented to show that the control strategy developed in this project significantly reduces the gap between the drivability of a starting clutch vehicle and a torque converter equipped vehicle.


Author(s):  
Tarek Omar ◽  
Nabih E. Bedewi ◽  
Timothy Hylton

Terrorist attacks became a major threat to the safety, security, and economy of our nation in the last few years. The Attacks against important facilities could have different techniques; however the main source of ground attacks is the application of excessive amount of energy to the designated facility through a vehicle intrusion and/or a blast. In the current research, a new approach of using steel-structure barriers is presented. Several new structural anti-ramming barriers are designed and analyzed using nonlinear Finite Element Analysis (FEA). In this new design, commercial steel-structural components were used in order to reduce the manufacturing cost. These new steel-structure security devices have proven an excellent capability to sustain severe impacts by spreading substantial amount of the impact energy throughout the entire structure and the supporting soil/concrete. In the current research, three anti-ramming bollard systems, for K4, K8 and K12 impact conditions, were presented. The bollard systems were made of commercial steel unites connected together to produce the entire bollard structure. The FE modeling and simulation results of the bollard systems were presented in details in this paper. The FEA for the K4 bollard was validated by comparing the simulation results with the actual test results. The FE simulation results correlated very well with the actual test results. The steel-structure barriers could have much less shallow foundation to account for the in-city utility restrictions. It also has the advantage of easier and faster installation minimizing the required digging and installation time inside the city. The design could also be modified to account for different threat levels and different sites’ restrictions.


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