Six-speed Automatic Transmission Research Articles

A Fast Optimizing Method of Clutch–Clutch Shift Calibration Parameters

Aiming at the drawbacks of the heavy workload and lengthy calibration cycle of transmission control unit (TCU) development, a fast optimizing and test method of clutch–clutch shift calibration parameters is developed based on the “V” development process. A controlled-object simulation model of a six-speed automatic transmission (6AT) is established, and the shift calibration parameters and shift quality evaluation system are studied. Therefore, a model-in-the-loop (MIL) calibration platform for key calibration parameters and evaluation indicators in the shift process is constructed. By setting the optimization target of evaluation indicators, the initial calibration parameters’ ranges are reduced. Finally, the TCU is flashed with the optimized calibration parameters, and a hardware-in-the-loop (HIL) test system is built to verify the shift quality. The same shift quality verification test is carried out in the vehicle. The test results show that the application of the MIL simulation platform can enable the batch simulation analysis of eight key shift calibration parameters, gradually refine the initial rough interval, and ensure shift quality. The shift calibration parameters are cross-validated in multiple development links, and the dependence on vehicle calibration is greatly reduced. The development cycle is effectively shortened to less than 6 months.

Unified Power-Based Vehicle Fuel Consumption Model Covering a Range of Conditions

<div class="section abstract"><div class="htmlview paragraph">Previously fuel consumption on a drive cycle has been shown to be proportional to traction work, with an offset for powertrain losses. This model had different transfer functions for different drive cycles, performance levels, and applied powertrain technologies. Following Soltic it is shown that if fuel usage and traction work are both expressed in terms of cycle average power, a wide range of drive cycles collapse to a single transfer function, where cycle average traction power captures the drive cycle and the vehicle size. If this transfer function is then normalized by weight, i.e. by working in cycle average power/weight (P/W), a linear model is obtained where the offset is mainly a function of rated performance and applied technology. A final normalization by rated power/weight as the primary performance metric further collapses the data to express the cycle average fuel power/rated power ratio as a function of cycle average traction power/rated power ratio. This final transfer function is mainly a function of technology. It was used to estimate the effectiveness of technologies deployed by manufacturers to improve fuel consumption. Compared to the naturally aspirated PFI engines and six-speed automatic transmissions of a decade ago, three different combinations of downsized turbo or Atkinson engines, with either 8+ speed transmissions or CVTs achieve similar substantial improvements in efficiency. The useful work or power definition is expanded to include electrical power for customer functions, and power to drive the air conditioning, so that the model can be applied to ‘real world’ driving.</div></div>

Design of A Planetary Gear Mechanism of A Seven-speed Automatic Transmission Based on the Lever Method

The existing six-speed automatic transmission of Toyota AB60E has the shortcomings of large number of transmission actuators and complicated structure. The paper first uses the lever method to analyze the lever diagram of each gear of the transmission. And then, based on the six-speed automatic transmission of Toyota AB60E, a new seven-speed automatic transmission is designed. The lever method is used to analyze the speed of each component of the newly designed one and the relative speed of its shift actuators and planetary gears. Finally, the external torque of the device and the internal torque of each component are calculated. The results show that, with the same structure parameters of the planetary row, the number of shift actuators of the new transmission decreases to 6 and the gears increase to 7. The transmission ratio between gears is closer, and the overall performance is better than that of the transmission of AB60E. The automatic transmission of planetary gears can be designed quickly by the lever method, and the kinematics and dynamics analysis can be carried out.

Design and Optimization of Clutch Hydraulic Shift Control System in Automatic Transmissions with Failure Protection Function

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.

Nomographs for synthesis of epicyclic-type automatic transmissions

This paper presents a MATLAB optimization technique for the determination of the gear ratios of epicyclic-type transmission mechanisms for a given set of velocity ratios. First, all of the feasible clutching sequences are enumerated directly without using complicated techniques. Then, for the transmission mechanism with the associated clutching sequence graph, the overall velocity ratios are derived and expressed in terms of the gear ratios of all the mating gears. Next, following the general trend of increased shift stages and a wider range of velocity ratios, the numbers of teeth of all gears are estimated by MATLAB optimization technique in a single run. Ravigneaux gear mechanisms are used as design examples. The methodology can be applied to any transmission mechanism depending on its kinematic and geometric constraints. New five- and six-velocity automatic transmissions are enumerated from the Ravigneaux gear mechanism. It is a major breakthrough to design a completely satisfactory six-speed automatic transmission from the Ravigneaux gear mechanism since it has only eight links. The new design makes use of the benefits of the Ravigneaux gear train and overcomes the previous art difficulties. This structural design has realized a six-speed automatic transmission, while having minimal number of clutches, and brakes. It is also low cost due to adoption of the conventional available Ravigneaux gear train.

Six-speed automatic transmission in the opel astra and for the global market

General Motors Powertrain has developed a new six-speed FWD family of automatic transmissions for compact and midsize vehicles. These are also used for the European market, as they are put into the new Opel Astra since October 2009. Due to its compact shape, high quality and good value-for-money level, this transmission can be integrated in all vehicle platforms and is thus suitable for global markets. As compared to the four- and five-speed transmissions which it replaces, the new six-speed transmission excels by its improved fuel economy as well as its improved performance.

Six-speed Automatic Transmission in the Opel Astra and for the Global Market

General Motors Powertrain has developed a new six-speed FWD family of automatic transmissions for compact and midsize vehicles. These are also used for the European market, as they are put into the new Opel Astra since October 2009. Due to its compact shape, high quality and good value-for-money level, this transmission can be integrated in all vehicle platforms and is thus suitable for global markets. As compared to the four- and five-speed transmissions which it replaces, the new six-speed transmission excels by its improved fuel economy as well as its improved performance.

Vamac selected for automatic transmission seals

SKF Korea has switched to bonded piston seals of Vamac ethylene acrylic elastomer (AEM) to meet the performance demands from GM Daewoo Auto Technology for the GF6 six-speed automatic transmission system.

Further developed six-speed automatic transmissions by BMW

Ever since their launch, BMW six-speed automatic transmissions have been the embodiment of exceptional gearshift dynamics, combining the highest levels of gearshift comfort and low fuel consumption. A further developed six-speed automatic transmission is making its debut to coincide with the presentation of the BMW 3 Series Coupe. The guiding principle behind the new transmission generation is “efficient dynamics”, and it achieves top marks in terms of responsiveness, gearshift dynamics and fuel efficiency.

The new Audi 4.2 l V8 TDI-engine

The first part of this report [1] discusses the design and mechanical aspects of Audi’s new 4.2 l V8 TDI engine. The second part describes the development of thermodynamics, application and exhaust-gas after-treatment. The new V8 diesel engine has a maximum power output of 240 kW at 3750/min and 650 Nm of torque at between 1600 and 3500/min. It will be deployed in the Audi A8 with six-speed automatic transmission and a quattro drive unit.

The new six-speed automatic transmission for the mini cooper S

The Mini Cooper S can now be ordered with a six-speed automatic transmission. A spontaneous response, quick shift times and direct multiple down-shifts at kickdown will enthuse also the Mini pilot who prefers a sporty driving style for an automatic transmission. The Mini Cooper S automatic transmission offers the customer a higher driving comfort without compromising the first-class driving dynamics.

CONFIGURATION DESIGN OF SIX-SPEED AUTOMATIC TRANSMISSIONS WITH TWO-DEGREE-OF-FREEDOM PLANETARY GEAR TRAINS

A methodology is proposed herein to search for and synthesize feasible configurations of six-speed automatic transmissions based on planetary gear trains with two degrees of freedom. A screening ru...

The diesel power units in the new BMW 7-Series

Particularly in the luxury performance segment, diesel engines have become very significant in Europe over the years. Serving as power units for the new BMW 7-Series, the 3.0-litre straight-six and 3.9-litre V8 diesel engines which already featured in the previous models have been fundamentally revised and updated. Like the 8-cylinder gasoline engines introduced last autumn at the launch of the new 7-Series, the two new diesel engines are combined exclusively with the latest-generation six-speed automatic transmission.

Six-speed automatic transmissions and CVT’s to support fuel economy

Improving fuel economy and reducing CO2 emissions have a high priority in passenger car development. New 6-speed automatic transmissions and continuously variable transmissions (CVT) will be available in a larger range of vehicles in Europe in the near future. These transmissions will fulfil the requirements for reducing fuel consumption and emissions and will increase performance and driving comfort at the same time.

The new BMW 7 Series cooling system

To satisfy customers’ high expectations of the new 7 Series in terms of dynamics, comfort, fuel consumption and environmental compatibility, new 8-cylinder petrol engines and a new six-speed automatic transmission were developed. The new cooling system also makes an important contribution to the fulfilment of these requirements. The simultaneous development of the vehicle and the powertrain permitted an ideally matched thermal management system to be designed. In the process, a number of new solutions was developed which also reduce production and maintenance costs.