Data processing: vehicles – navigation – and relative location – Vehicle control – guidance – operation – or indication – Transmission control
Utility Patent
1999-04-07
2001-01-02
Cuchlinski, Jr., William A. (Department: 3661)
Data processing: vehicles, navigation, and relative location
Vehicle control, guidance, operation, or indication
Transmission control
C701S054000, C701S087000, C701S094000, C477S107000, C477S115000
Utility Patent
active
06169949
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a control apparatus in which in particular a continuously variable transmission among automatic transmission for a vehicle s becomes to be as a control subject and a control method thereof, and in particular relates to a control apparatus of an automatic transmission for a vehicle where even a road gradient of a road surface in which a vehicle runs varies, a necessary driving force or an engine brake can be obtained automatically and thereby the vehicle can be run safely and a control method of an automatic transmission for a vehicle.
Up to now, as to a control method of an automatic transmission for a vehicle, for example, as described in Japanese application patent laid-open publication No. Sho 63-57953, one method has been known in which a present transmission ratio (a present pulley ratio) is requested by a pulley ratio between an input side pulley (a primary pulley) and an output side pulley (a secondary pulley) of a continuously variable transmission (CVT) and a rotation number of the pulley and a control of a transmission ratio (a pulley ratio) is controlled to coincide this present transmission ratio (the present pulley ratio) with a target transmission ratio (a target pulley ratio) which is requested according to a state amount of a vehicle which has memorized in advance in a control apparatus, or another method has known in which an input side pulley rotation number is varied to coincide to a target input side pulley rotation number.
Further, it will be explained in concretely, from the target input side pulley rotation number which is requested by a running condition of the vehicle the target transmission ratio (the target pulley ratio) is calculated and a command value for operating a transmission use actuator of an automatic transmission is calculated from the target transmission ratio (the target pulley ratio) and this command value is outputted.
Further, as a control method, a total value of a feed forward loop and a feed back loop is made as a command value of a transmission use actuator, such a feed back loop is calculated a command value according to a proportional and integral execution in which a difference between the target input pulley rotation number and an actual input pulley rotation number is formed as a deviation.
In the above stated prior arts, during a flat road surface running there is no transmission chock different from a vehicle having a stepped stages transmission and the performances such as an acceleration feeing are good, however when there is a road surface gradient, following problems occur.
For example, when the vehicle is on a down hill, a driver returns an acceleration pedal by hoping an engine brake with an aim for lowering a vehicle speed, however in a case of the conventional automatic transmissions a shift-up causes by returning the acceleration pedal and the vehicle speed is increased and the driver is caused to have a consideration which differs from his intention and according to the circumstances the driver may be given an afraid about a fear feeling.
Accordingly, during the down hill the driver carries out frequently a foot brake, however following conditions cause in which by stepping continuously the foot brake the brake oil is boiled and then the brake becomes ineffective or a brake pad is worn early and then the brake becomes ineffective.
As the countermeasures against the above facts, to making effectively the effect of the engine brake during the down hill in the automatic transmission the driver can carries out positively the change-over of a range (a range selection) by the shift-down, as described in a vehicle use explanation. However, there is a report in which the driver who carries out positively the range change-over (the range selection) is few, accordingly it is necessary to carry out a countermeasure using a control method.
Further, when an up hill (a hill climb) continues, when a trample down of the acceleration pedal is not carried out, the vehicle speed lowers naturally. In a case of abrupt climb road gradient, it is necessary to carry out the trample down largely and by this trample down, the shift-down is carried out, accordingly a drive torque is increased.
In the case of the vehicle having the continuously variable transmission (CVT), together with the trample down of the acceleration pedal, the transmission ratio (the pulley ratio) is changed gradually to a low side. However, in the case of the abrupt climb road gradient, it is necessary to carry out the range change-over (the range selection) by the driver and then the driver may be given to feel a nuisance.
On the other hand, in a microprocessor installed in an interior portion of the control apparatus of the automatic transmission, the drive torque and the road surface gradient are estimated and executed from an engine condition amount such as an engine rotation number and a throttle valve opening degree etc. and the transmission ratio is controlled suitably.
As a recently technical tread, in a case of a lean air fuel ratio control engine and a fuel direct injection system engine, due to an increase of the parameters for requesting an output torque and a change in time lapse, the estimation and execution of the drive torque and the road surface gradient becomes complicatedly.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a control apparatus of an automatic transmission for a vehicle wherein a driving force in response to a road surface gradient can be obtained by a driver himself without a change-over of a transmission mode and a control method of an automatic transmission for a vehicle.
Further, in a non-conventional system such as a lean air fuel ratio control engine and a fuel direct injection system engine, a transmission ratio (a pulley ratio) is controlled automatically in response to a road surface gradient, and the transmission ratio can be controlled automatically, in a case of a down hill road gradient a moderate engine brake suited to the road gradient can be obtained and further in case of an up hill (a hill climb) road gradient a moderate drive force suited to the road gradient can be obtained.
According to the present invention, in a control apparatus of an automatic transmission for a vehicle, a command value is calculated in response to an engine rotation number, an input side pulley rotation number of a continuously variable transmission (CVT), and an information indicating a condition of a vehicle such as a vehicle speed of the vehicle and a throttle valve opening degree.
According to the above stated command value a command is inputted, by varying an interval of a V shape groove of an input side pulley (a primary pulley) and an output side pulley (a secondary pulley) and by varying a pulley winding valid radius of a belt which is hung between said both pulleys (the primary pulley and the secondary pulley), a transmission ratio (a pulley ratio) is changed continuously variable and then a transmission control is carried out, the control apparatus has a road gradient estimation block for calculating a road gradient of a running road surface and a target vehicle speed value decision block for deciding a speed of the vehicle in accordance with the road gradient of the road surface, and the transmission ratio (the pulley ratio) is controlled to have the vehicle speed having a constant value under a basis of the vehicle speed when the vehicle is on at the road gradient.
Further, the road gradient estimation block receives the information for indicating the engine condition from a control apparatus of the engine and this road gradient estimation block comprises a torque calculation block for estimating the drive torque of the vehicle, a running load resistance calculation block for calculating the running load resistance under a basis of the vehicle speed, and an acceleration torque calculation block for calculating the acceleration torque of the vehicle according to the vehicle.
With the above stated means, a target value of the vehicle speed is req
Beaulieu Yonel
Cuchlinski Jr. William A.
Evenson, McKeown, Edwards & Lenahan P.L.L.C.
Hitachi , Ltd.
LandOfFree
Control apparatus of automatic transmission for vehicle and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Control apparatus of automatic transmission for vehicle and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Control apparatus of automatic transmission for vehicle and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2489114