Hitachi, Ltd.

Hitachi Automotive Engineering Co., Ltd.

Hiroshi Ohnishi

Toshimichi Minowa

Mitsuo Kayano

Tatsuya Ochi

Naoyuki Ozaki

Matsuo Amano

Nobuo Kurihara

Hiroshi Sakamoto

Mineo Kashiwaya

Kouji Kitano

Hiroshi Kuroiwa

Masahiko Ibamoto

Kazuhiko Sato

Junichi Ishii

Makoto Uchida

Takashi Okada

Hiroshi Katayama

Michimasa Horiuchi

Ryouichi Naganuma

An automatic transmission control system for an automobile, comprising a vehicle weight estimation unit which estimates a vehicle weight of the automobile a torque estimation unit which estimates an output torque, an acceleration input unit which accepts an acceleration signal; a load estimation unit (110) which estimates a running load from the estimated vehicle weight, the estimated output torque and the accepted acceleration; a memory which stores a plurality of shift schedules therein; and a gear position determination unit (109) which includes the memory, and which selects one of the shift schedules in accordance with the vehicle weight and the estimated running load, so as to determine a gear position of an automatic transmission of the automobile in conformity with the selected shift schedule. An exact shift operation conformed to the vehicle weight and the running load can be performed, and an enhanced fuel consumption can be attained.

Automatic automobile transmission with variable shift pattern controlled in response to estimated running load

An automatic transmission control system for an automobile, comprising a vehicle weight estimation unit which estimates a vehicle weight of the automobile a torque estimation unit which estimates an output torque, an acceleration input unit which accepts an acceleration signal; a load estimation unit () which estimates a running load from the estimated vehicle weight, the estimated output torque and the accepted acceleration; a memory which stores a plurality of shift schedules therein; and a gear position determination unit () which includes the memory, and which selects one of the shift schedules in accordance with the vehicle weight and the estimated running load, so as to determine a gear position of an automatic transmission of the automobile in conformity with the selected shift schedule. An exact shift operation conformed to the vehicle weight and the running load can be performed, and an enhanced fuel consumption can be attained.

Automatic transmission control system for an automobile

A vehicle transmission system has a gear-type transmission with a plurality of gears and a plurality of claw clutches which transmits a torque between an input shaft of said gear-type transmission and an output shaft of said gear-type transmission. The transmission changes transmission courses by engaging with and/or disengaging from the gears and the claw clutches, and forms another transmission course via a torque controller between the input shaft of the gear-type transmission and the output shaft of said gear-type transmission during a period between a first transmission course and a second transmission course formed by the gears and the claw clutches. A torque capacity of the torque controller is greater than the maximum output shaft torque of the transmission.

Gear-type automatic transmission and an automobile using the gear-type automatic transmission

Gear-type automatic transmission and car using the gear type automatic transmission

A mesh type automatic transmission is equipped with a plurality of shift gears arranged to rotate freely to an output shaft for providing driving force to the wheels. Cogged clutches engage with the output shaft. Counter shift gears corresponding to each speed are fixed to a counter shaft rotated by the rotation of an input shaft and mesh with the shift gears for performing automatic shifting by controlling engagement of one of the cogged clutches with the voluntary shift gears determined from the accelerator command value and the vehicle speed. An assist mechanism transmits rotational force of the input shaft to the output shaft via the assist shaft which rotates from the rotation of the counter shaft when no cogged clutch of the plurality of cogged clutches is engaged with any of the plurality of shift gears occurring during switching when an engaged cogged clutch of the plurality of cogged clutches is disengaged and one of the cogged clutch of the plurality of cogged clutches is to be engaged.

Automatic transmission

An apparatus for controlling an automatic transmission of an automobile and a control method thereof. When a feedback control is executed by the automatic transmission while the speed is being changed, the control operation may often lose stability. This is due to a large deviation between a target value and a practical value at the start of the feedback control operation being caused by a change in the opening degree of the throttle and a change in the oil temperature in the automatic transmission. To solve such a technical problem, the invention employs a control apparatus which detects that the automatic transmission is changing the speed, operates the output shaft torque of the automatic transmission, recognizes a point of inflection of the output shaft torque while the speed is being changed, sets a target output shaft torque of the automatic transmission, and sets an initial target value at a moment of said point of inflection.

Control apparatus for an automatic transmission of a vehicle and method

An engine power train control method and control apparatus for a vehicle having an engine and an automatic transmission is capable of quickly changing an air-fuel ratio to meet the requirements for exhaust gas without producing shocks and without reducing engine torque. An air-fuel ratio command value is varied stepwise for transition between an air-fuel ratio for lean-burn operation and a stoichiometric air-fuel ratio, and at the same time, the period following the completion of the stepwise variation of the air-fuel ratio command value, a basic fuel amount fed to the engine is varied stepwise from a value determined according to the air amount and an engine speed to a value determined according to a position of an accelerator pedal of the vehicle and the engine speed. In this way, shocks do not occur and the operability is improved, because the engine torque remains substantially constant through the air-fuel ratio transition.

Engine power train control method and control apparatus for a vehicle

An apparatus and method control an automatic transmission of an automobile. When a feedback control is executed by the automatic transmission while the speed is being changed, the control operation may often lose stability due to a large deviation between a target value and a practical value at the start of the feedback control operation being caused by a change in the opening degree of the throttle and a change in the oil temperature in the automatic transmission. To solve such a technical problem, the control apparatus which detects that the automatic transmission is changing the speed, operates the output shaft torque of the automatic transmission, recognizes a point of inflection of the output shaft torque while the speed is being changed, sets a target output shaft torque of the automatic transmission, and sets an initial target value at a moment of the point.

The invention provides an output torque control method and apparatus for a lean burn internal combustion engine which accounts for aging of component parts, and in which no stepwise change of torque or shock occur when an air fuel ratio is changed. The method and apparatus according to the invention control an intake air amount while maintaining an emission purification function by controlling the air fuel ratio to that of a theoretical mixture (air fuel ratio of 14.7) in a case where a limit NOx emission is determined by using a detected air fuel ratio and lean burn operation becomes difficult due to the amount of NOx emissions. Abrupt change of an output torque when the air fuel ratio is changed is curtailed by controlling a fuel amount or an air amount after calculating the fuel amount or the air amount from an engine speed and an accelerator depression angle.

Output torque control apparatus and method for an internal combustion

A method and apparatus to estimate slopes accurately, as well as to eliminate slope estimation errors, taking error generating conditions into account. The slope on which the vehicle is running is estimated from the vehicle speed and the engine rpm value. The result is entered to the slope estimation unit through a low pass filter, then to the navigation unit. A noise eliminator is provided to the output of the slope estimation unit so that noises can be eliminated, for example, during gear-shifting or for a certain time after the gear shifting is completed by obtaining the 'gear shifting' information from the automatic transmission control. The preceding estimated slope value is held during the noise elimination period.

Method and apparatus for eliminating noise in a slope estimation

Detecting means for detecting driving conditions of a vehicle such as engine load such as throttle opening, vehicle speed, gear position or gear ratio and so on and memory means for storing characteristics of the vehicle such as engine power characteristic, torque converter characteristic, fuel consumption rate characteristic and so on are provided. Driving shaft torques before and after gear shift, an estimating value of fuel consumption rate and a gear shift point of a transmission are calculated in real time to perform transmission control using the signals from said detecting means and the signals from said memory means. With the construction according to the present invention described above, an automatic transmission can be controlled in real time by calculating a gear shift point of the transmission in a short time through estimating the driving shaft torques before and after gear shift.

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Hitachinaka, Japan

Hiroshi Ohnishi