Shift Schedule And Simulation Of Automatic Transmission

Automatic gear shifting is the target which people are seeking over a long period of time. It is significant sign of automobile evolving to the advanced stage and the important technology which desiderate developing and spreading. The automatic transmission of automobile is divided into Automatic Transmission (AT), Automatic Mechanical Transmission (AMT), Continuously Variable Transmission (CVT). The automobile with automatic transmission (AT) has smooth gear shifting and convenient operation. Moreover, it cans automatically gearshift in term of optimal occasion, redounding to the improvement of dynamic performance and fuel economy. The amount of cars with AT has increased greatly all over the world. Internal automobile industry of China is in developmental period and domestic cars are increasing gradually of late years. For satisfying the curbstone driver's request for simple handle, many manufactures have considered AT as their development direction.In the course of AT researching, developing and matching with the entire vehicle, the characteristic of the power train which mainly consists of engine and automatic transmission, need to be analyzed. Base on this, optimization design and domination control can be realized. Using the simulation system, we can divine and analyze the performance of the entire vehicle without actual engine and vehicle. This is an economical and efficient means, especially in the design stage of product.According to the project"Optimal Shift Schedule with Dynamic Tri-Parameters"of GM Company, a series of research have been carried out. First, the advantages, disadvantages and development prospects of various transmissions are analyzed according to the classification of automotive transmission. The development process, characteristics, system configuration of these transmissions is also introduced. Describe the change of torque and fuel of engine at steady and unsteady condition, and analyzed the affect to the vehicle. Based on the data on GM models, analyzed the original performance, evaluation and dynamic characteristics of hydraulic torque converter. Through the torque convert and engine work together, analyzed the match principle of torque an engine, and discussed the input and output performance. According to the classification method of the theory of intelligent, this describes the shift schedule, and characteristics of them.Through the vehicle dynamics analysis, driving formula, and based on formula development shift schedule of the automatic transmission. Shift schedule is the regulation that the time of automatically shifting between two shifts changes with the control parameter's variety. As to the automatic transmission automobile, shift schedule decides whether the automobile shifts on the best shifting point, decides the exerting extent of the vehicle performance. Shift schedule has great influence on the performance of the vehicle, and different shift schedule has different influence, therefore we hope to look for the shift schedule which is of more benefit to develop the automobile's functions by comparing and evaluating the different shift schedules, so, the evaluation of shift schedule comes to more important. Taking into account the fuel economy of cars, according to GM models of data, transmission used in the hydraulic torque converter condition at 1st, 2ed shift, at the remaining shifts the locking clutch is locked, used engine condition. Analyzed how to establishing the shift schedule of power performance, including the graphical method, analytic method, and established the shift schedule of adjacent gear. Analyzed the factor which impact the fuel economy, and set up the fuel consumptions equations, Analyzed how to establishing the shift schedule of fuel economy, including the graphical method, analytic method. It is very difficulty apply the tri-parameter on the vehicle, so put a new shift schedule that based on the fuel economy, at the same time also consider the power performance. Utilizing the software of iSIGHT optimize the shift schedule in the fuel economy region, and make it not only satisfy the low fuel consumption but also satisfy the power performance. Establish the model of power train of vehicle with the Matlab/Simulink, and introduce the principle of operation and theory of each module. Put the optimize shift schedule and the fuel economy shift schedule into the model, and compare the time from 0 to 100 km/h, the results indicate the power performance of the shift schedule is better than the tri-parameter. Consider the vehicle usually work on the middle throttle, so in this condition compare the fuel economy. The result indicate the fuel economy of tri-parameter is better than the optimize shift schedule, and the optimize shift schedule reach the target setting.