Papers by Keyword: Automatic Transmission

Abstract: 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.

Abstract: As a significant control component of vehicles, automatic transmissions should have failure protection function. The failure protection function partly is determined by the hydraulic control system. However traditional design could not cover all of failures, and there is no general design method. A design method is proposed for designing the shift control oil circuit of the hydraulic control system with the failure protection function. . The design method is applied to optimize the hydraulic control system of a six-speed automatic transmission. The function of the optimized hydraulic control system is confirmed by the dynamic simulation. The results show that the design method can simplify the hydraulic control system without losing any original functions. The proposed design method is proved to be suitable for all kinds of hydraulic control systems of automatic transmissions.

Abstract: Using of the simulation tool Romaxdesigner to designe new seven-speed Automatic Transmission and get the reasonable spatial arrangement .Meanwhile ,the simulation results prove the reasonable of leverage method applied in designing the Automatic Transmission .

Abstract: Aiming at the deficiencies of the commonly used AMT and DSG structure in the electric vehicles’ transmission, a kind of three-speed automatic transmission structured by the planetary gear trains is designed. It uses the centrifugal components to realize the gear shifting, while using the electromagnetic brake and the motor reversal to realize the reversing. Based on the design concepts proposed, we did some matching calculations on the transmission system of a three-wheel pure electric vehicle, and finally made the optimization design on the driving motor’s selection and transmission parameters. The designed electric vehicle’s centrifugal automatic transmission has the characteristics of simple structure, small size and shifting smoothness, which can not only meet the requirements of the automobile power, but also improve the efficiency of the driving motor.

Abstract: 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.

Abstract: The control technology of automatic transmission is mainly to solve the decision problem of shift strategy, namely according to the factors of intention of the driver, vehicle running state, road conditions and the principle of the optimal vehicle performances, determine the best gear. This paper mainly studies shift strategy under different driver intention, different driving condition of the vehicle, different use of vehicle.

Abstract: The speed is the most common frequency signal among a lot of the automotive signal which may be collected, Acquisition for frequency signal generally use the counter input capture. The number of sampling rate not only depends on clock frequency counter, but mainly the number of the frequency of the signal itself, it is bound to take a very long time to collect speed signal when the speed is very low. For most of the data acquisition card, which usually adopt asynchronous acquisition between various channels, that is, only one channel can collect data at any time, so for the multi-signal acquisition system which has a high requirement for real-time, it is undue to collect directly low frequency signal. This paper adopt method of frequency-voltage converter to change the frequency signal to analog signal and collect data, thus, which can greatly improve the system's sampling rate.

Abstract: This paper studies the electric-drive mechanical transmission-EMT which integrates motor and mechanical transmission system. The system follows the principle of power-train integration, the paper uses the CATIA software for virtual manufacturing and assembling, through the written simulation program, using Matlab software transmission to design module simulation studying of the institution, to verify that the three grades EMT system is better in efficiency and fuel economy performance, to provide theoretical research guidance for the product designing.

Abstract: In general, discomfort and slipping loss cannot be avoided during gearshift due to discrete gear ratio. Therefore, improving shift quality has long been concerned in the developing process of automatic transmission. This paper presents the equivalent dynamic model of automatic transmission, based on which optimal theory is then applied to obtain ideal engaging/disengaging torque control. Driving intention is also taken into consideration in the optimal control by deciding the weighted values for slipping loss and jerk items in the target function with fuzzy logic method. The simulation results show a good reflection of driving intention and could be used to decide band/clutch apply pressure in the control unit developing process afterwards.

Abstract: For the development research for a new 8 step speed automatic transmission, a simplified dynamic model for this transmission was established. Aimed at four basic shift types, the ideal characteristics of shift clutch and engine control were set up. By using torque estimation method, PI slip control algorithm and engine coordinated control principle, the control model were developed for two main shift phases which are torque phase and inertia phase. The test on the rig and vehicle verified the accuracy and feasibility of this shift control strategy. The development model and algorithm have a high value for engineering application.