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It has been past over 10 years since the slip-controlled clutch has adopted to torque converters as improvement technology of fuel consumption. In the recent trend, the updated demand is use of expanded slipping control for further improvement of the transmission efficiency. However, there are the cases of vibration issues in slip-controlled torque converter clutches. This issue is called shudder as typical problem of vehicle vibration. In design of torque converter, it is known as the importance to manage μ -V property preventing from shudder vibration. However, it was difficult to predict μ -V property on the actual system, because of its complex interface phenomena are caused by various changeable factors include physical and chemical. Therefore, if prototype design was never satisfied anti- shudder properties, we need to change design and lost much time to redesign it.

Toyota Motor Corporation has developed a new six-speed automatic transmission AB60E for longitudinal front engine rear wheel drive (RWD) vehicles. This transmission development was aimed at an improvement of power performance and fuel economy, while achieving a lightweight, compact package and a high torque capacity. In order to achieve this target, a high-capacity ultra-flat torque converter, a highly-rigid transmission case, and an ATF warmer with a valve to switch ATF circuits to an air-cooled ATF cooler have been newly developed. Moreover, a new transmission mode control logic “TOW / HAUL” has been developed to improve power performance and driveability during trailer towing. This automatic transmission has adopted the same gear train and hydraulic control system as the conventional six-speed automatic transmission A760E. This paper describes the structure, major features and performance of the transmission in detail.

TOYOTA has developed the world's first eight-speed automatic transmission (AA80E) for front-engine, rear-drive passenger cars. The AA80E developed for high-torque engines raises the level of power performance and fuel efficiency. To meet the size requirements needed for mounting in a passenger car application, an 8-speed geartrain, torque converter, transmission case and hydraulic control device were all newly-developed. Furthermore, the AA80E has benefited from technical developments to achieve an extremely high level of quietness and shifting performance. In this paper, the details of the AA80E are introduced.

Toyota has developed the world's first 8-speed automatic transmission (AA80E) for RWD automobiles. The transmission will first be used in the all-new Lexus LS460. In addition, a novel control system has been developed to maximize the predictability, response, efficiency, and initial quality of the powertrain while utilizing the high number of gear steps.

Toyota has developed a new sports shift control system introduced in the world's first eight-speed automatic transmission (AA80E), which is implemented in the “LS 460” and has been adopted in the “IS F” (upcoming 2008 model). This enables the IS F to be a vehicle that also permits the enjoyment of driving on circuits as well as achieving that “fun-to-drive” image. In sports driving, as achieved by the conventional torque converter-type automatic transmissions, shift response performance for shift operation and linearity performance for accelerator operations were challenges to tackle. On the contrary, the newly developed sports shift control system has resolved these challenges and enables the IS F to be capable of responding to a driver's intention quickly and accurately, letting the driver truly experience satisfaction.

AISIN AW has developed a six-speed automatic transmission TF-60SN for front wheel drive (FWD) vehicles. This new TF-60SN has been developed based on the concepts of minimizing length and mass increase as compared with current five-speed automatic transmissions, and providing the world's first transverse FWD six-speed automatic transmission. This has been accomplished using a newly developed planetary gear set, and a new “squeezed” torque converter. In addition, the control system features a unique design that maintains outstanding compactness and achieves a high quality smooth shift feeling. This paper describes the construction, characteristics, and functions of this six-speed automatic transmission.

AISIN AW has developed a five-speed automatic transmission “55-50SN” for front wheel drive (FWD) vehicles. This new 55-50SN has been developed with a concept to minimize length and mass increase compared with the current four-speed automatic transmission, and is one of the most compact five-speed automatic transmissions in the world. This has been accomplished by newly developed planetary gear sets, a new differential, and a new squeezed torque converter. In addition, the control system is made by a unique design to maintain the excellent compactness and to achieve a high quality smooth shift feeling. This paper describes the construction, characteristic, and function of this five-speed automatic transmission.

Recently, 5-speed automatic transmissions have become mainstream through the world, and 6-speed automatic transmissions have also been introduced in the market. Consequently, the issue of shift control is gaining importance, and a trend toward increasing number of gears in automatic transmissions has become apparent. On the other hand, weight saving and downsizing of the transmission, including the hydraulic control unit, are strongly required in order to promote fuel efficiency. To meet these requirements, an electro-hydraulic control unit offering sophisticated functionality desired in order to provide excellent shift quality. As an answer to these requirements AISIN AW developed two types of new 6-speed automatic transmissions in 2002: “TR-60SN” for RWD vehicles and “TF-60SN” for FWD vehicles. Both TR-60SN and TF-60SN have the same structural characteristics.

As requirements for protecting the global environment are being heightened on a worldwide scale in recent years, the development of low fuel consumption technologies in order to inhibit the discharge of CO2 is an important issue for the automotive industry. Recently, Toyota has developed a Super CVT for the 1.3-to 1.5-liter class vehicles to further improve their fuel economy. This CVT has been adopted on vehicles equipped with the ‘idling stop system’. The ‘idling stop system’ automatically stops the engine when the vehicle is stopped and the transmission shift lever is in the ‘D’ position (e.g. when the vehicle is at a stoplight). This improves the fuel economy of the vehicle by eliminating fuel consumption while the vehicle is stopped. The conventional CVT poses unique conditions such as startoff time lag or shock after the engine is restarted. These conditions occur because the CVT oil pump cannot generate hydraulic pressure while the engine is stopped.

A newly developed classifying method for time series measurement data of automatic transmission of vehicles is presented. The proposed method uses deep convolutional neural networks to learn what is comfortable acceleration. In addition, our proposal method employs supervised learning based on experienced engineer’s criterion. As a demonstrative problem, we consider the classification of time series measurement data for lock-up clutch control of an 8 speed automatic transmission.

AISIN AW has developed a new Continuously Variable Transmission (hereafter CVT) with torque converter for small capacity engines. The target vehicles are B class cars. The following items are the concept of the development. - Compact size to be applicable to small cars in Japan (K-car). - The lightest in the world. - Low noise level in addition to improved fuel consumption. The CVT introduces neutral-control logic and a long-travel damper on the torque converter for expansion of the lock-up area.

Toyota Motor Corporation has developed a new five-speed automatic transmission (A750E/A750F) for longitudinal front engine rear wheel drive (RWD) vehicles. The development of this transmission has been aimed at improving fuel economy and power performance, achieving the world's top-level weight and compactness, while maintaining high torque capacity. In order to achieve this purpose, the gear train, torque converter, and other components are completely changed, and advanced technology has been applied. Moreover, this automatic transmission has achieved high-quality shift feel and quiet performance. This paper describes the major features and performance of this transmission in detail.

Toyota has developed a new full time 4WD system, called “EC-HYMATIC” or Electronically Controlled - HYdraulic Multi-plate clutch Active Traction Intelligent Control. This system permits an automatic torque transfer, depending on driving conditions, for front and rear wheels under control of the speed difference between the two. The system developed consists of a center differential, a speed difference control clutch system employing multi-plate clutch, and a gear set for rear axle drive. The speed difference control clutch system is controlled by a unique electro-hydraulic system using a microcomputer. An extensive use of computer simulations and vehicle test and evaluation has successfully developed an appropriate control strategy for the clutch system. The new 4WD system, EC-HYMATIC, considerably improves handling characteristics, traction performance and stability of a 4WD vehicle.

We developed a new automatic transmission control system that performs shift control for the automatic transmission (A/T) using the road data obtained from the navigation system, which previously had been used only for route guidance, and installed it in a new car, Progrès. This system reads the distance to the approaching corner and its shape based on the vehicle's position data and the data of the approaching road obtained from the navigation system, and determines the optimum gear based on these data and the current vehicle speed to perform optimum shift control in linkage with the driver's driving operation. In this paper, configuration, features and effects of this new A/T control system that takes consideration of navigation data are described.

Toyota Motor Corporation has recently developed a new six-speed automatic transmission (A761E) for Front Engine Rear Wheel Drive (FR) vehicles. Following the general trend of increased shift stages and a wider range of gear ratios, this six-speed automatic transmission has been developed with attention paid to the gear steps and a wider range of gear ratios. By balanced selection of close-ratio gears in a wider range, the change greatly improves the power performance and fuel economy of the vehicle. To further improve fuel economy we have adopted new technologies such as low-viscosity ATF, neutral control, and deceleration control by extending the fuel cut range (reset speed). We have also adopted a flat-shaped torque converter, small solenoids, an aluminum oil pump cover, etc. to realize the lightest six-speed automatic transmission in the world.

TOYOTA has developed a new automatic transmission, called the A341E. This transmission employs a unique engine and transmission integrated intelligent control system named “ECT-i”, and a high performance “Super Flow” Torque Converter. This control system is capable of total control of engine torque and clutch hydraulic pressure during shifting, which has resulted in very smooth shift without changes over the life of the transmission. The “Super Flow” Torque Converter has a modified geometry optimized by the analysis of internal flow by means of computer simulations, attaining the highest efficiecy in the world. With the use of such systems, this new automatic transmission has improved total performance of the vehicle.