US5558596A
Expired / Lapsed
US
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Method and system using fuzzy logic for controlling a CVT transmission
Assignee: Hitachi Ltd
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Filing: 1994-10-25
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Granted: 1996-09-24
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Expires: 2014-10-25
Abstract
Abstract According to the present invention, the driver's operation quantity and the vehicle running status are measured, the target value of speed ratio or the target value of revolution speed on the input side of the transmission is determined on the basis of the above measured values, and the speed ratio is changed using different algorithms (particularly fuzzy rules) on the basis of the magnitude of deviation between the target value and the actual value. Furthermore, when a vehicle has a continuously variable transmission, a change of at least one of the vehicle acceleration and the shaft torque of a drive wheel is predicted, the engine output torque is controlled on the basis of the prediction, and finite speed ratio characteristics or intermediate characteristics between finite speed ratio characteristics and continuously variable speed ratio characteristics are controlled for the continuously variable transmission. By doing this, speed ratio control stressed on stability is available when the absolute value of the above deviation is small, while speed ratio control stressed on rapid response and smooth acceleration variation is available when the absolute value of the deviation is large. Furthermore, a smooth acceleration feeling and a rapid acceleration response can be realized, the maneuverability is improved, and the driver can find pleasure in more speed ratio characteristics.
Inventors
- 👤 Masao Adachi
- 👤 Makoto Shioya
- 👤 Kazuhiko Sato
- 👤 Minoru Ohkubo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 23:43
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/66; F16H61/662; F16H61/66254; F16H61/66259; B; B60; B60W; B60W50/00; B60W2050/0001; B60W2050/0043; B60W2050/0057; F16H2061/0075; F16H2061/0081; F16H59/00; F16H59/14; F16H59/24; F16H59/36; F16H59/38; F16H59/40; F16H59/42; F16H59/48
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
157 words
In a vehicle transmission system including an operation sensor, a running status sensor, a processor and a memory storing relation data between target speed and data measured by use of said operation sensor and said running status sensor, a speed ratio control method for a continuously variable transmission which transfer inputs from a power source to a drive wheel, comprising the steps of; measuring through said operation and said running status sensors, a driver's operation quantity and a vehicle running status; determining through said processor, by use of said relation data, one of a target value of speed ratio and a target value of revolution speed on an input of said transmission on a basis of results of said measuring step; and changing a speed ratio using at least two different algorithms in correspondence with whether or not a value of deviation between said target value and a current actual value is greater than a threshold value.
Claim 2
Dependent Claim
157 words
In a vehicle transmission system including an operation sensor, a running status sensor, a processor and a memory storing relation data between target speed and data measured by use of said operation sensor and said running status sensor, a speed ratio control method for a continuously variable transmission which transfer inputs from a power source to a drive wheel, comprising the steps of; measuring through said operation and said running status sensors, a driver's operation quantity and a vehicle running status; determining through said processor, by use of said relation data, one of a target value of speed ratio and a target value of revolution speed on an input of said transmission on a basis of results of said measuring step; and changing a speed ratio using at least two different algorithms in correspondence with whether or not a value of deviation between said target value and a current actual value is greater than a threshold value.
Claim 3
Dependent Claim
42 words
A speed ratio control method for a transmission according to claim 1, wherein a changing in said changing step is performed on a deviation and velocity of deviation variation when an absolute value of said deviation is smaller than a predetermined value.
Claim 4
Dependent Claim
169 words
In a vehicle transmission system including an operation sensor, a running status sensor, a processor and a memory storing relation data between target speed and data measured by use of said operation sensor and said running status sensor, a speed ratio control method for a continuously variable transmission which transfer inputs from a power source to a drive wheel, comprising the steps of; measuring through said operation and said running status sensors, a driver's operation quantity and a vehicle running status; determining through said processor, by use of said relation data, one of a target value of speed ratio and a target value of revolution speed on an input of said transmission on a basis of results of said measuring step; and changing a speed ratio using at least two different algorithms in correspondence with whether or not a value of deviation between said target value and a current actual value is greater than a threshold value; wherein at least one of said different algorithms uses fuzzy logic rules.
Claim 5
Dependent Claim
169 words
In a vehicle transmission system including an operation sensor, a running status sensor, a processor and a memory storing relation data between target speed and data measured by use of said operation sensor and said running status sensor, a speed ratio control method for a continuously variable transmission which transfer inputs from a power source to a drive wheel, comprising the steps of; measuring through said operation and said running status sensors, a driver's operation quantity and a vehicle running status; determining through said processor, by use of said relation data, one of a target value of speed ratio and a target value of revolution speed on an input of said transmission on a basis of results of said measuring step; and changing a speed ratio using at least two different algorithms in correspondence with whether or not a value of deviation between said target value and a current actual value is greater than a threshold value; wherein at least one of said different algorithms uses fuzzy logic rules.
Claim 6
Dependent Claim
234 words
In a vehicle transmission system including an operation sensor, a running status sensor, a processor and a memory storing relation data between target speed and data measured by use of said operation sensor and said running status sensor, a speed ratio control method for a continuously variable transmission which transfer inputs from a power source to a drive wheel, comprising the steps of; measuring through said operation and said running status sensors, a driver's operation quantity and a vehicle running status; determining through said processor, by use of said relation data, one of a target value of speed ratio and a target value of revolution speed on an input of said transmission on a basis of results of said measuring step; and changing a speed ratio using at least two different algorithms in correspondence with whether or not a value of deviation between said target value and a current actual value is greater than a threshold value; wherein said changing step is performed according to when an absolute value of said deviation is larger than a predetermined value, said speed ratio is changed based on an at least one of a vehicle acceleration value, and a value which is at least one of a ratio and difference between a predicted time until said deviation becomes 0, and a predicted response time necessary for stopping a speed by use of a speed ratio control actuator.
Claim 7
Dependent Claim
234 words
In a vehicle transmission system including an operation sensor, a running status sensor, a processor and a memory storing relation data between target speed and data measured by use of said operation sensor and said running status sensor, a speed ratio control method for a continuously variable transmission which transfer inputs from a power source to a drive wheel, comprising the steps of; measuring through said operation and said running status sensors, a driver's operation quantity and a vehicle running status; determining through said processor, by use of said relation data, one of a target value of speed ratio and a target value of revolution speed on an input of said transmission on a basis of results of said measuring step; and changing a speed ratio using at least two different algorithms in correspondence with whether or not a value of deviation between said target value and a current actual value is greater than a threshold value; wherein said changing step is performed according to when an absolute value of said deviation is larger than a predetermined value, said speed ratio is changed based on an at least one of a vehicle acceleration value, and a value which is at least one of a ratio and difference between a predicted time until said deviation becomes 0, and a predicted response time necessary for stopping a speed by use of a speed ratio control actuator.
Claim 8
Dependent Claim
197 words
In a vehicle transmission system including an operation sensor, a running status sensor, a processor and a memory storing relation data between target speed and data measured by use of said operation sensor and said running status sensor, a speed ratio control method for a continuously variable transmission which transfer inputs from a power source to a drive wheel, comprising the steps of; measuring through said operation and said running status sensors, a driver's operation quantity and a vehicle running status; determining through said processor, by use of said relation data, one of a target value of speed ratio and a target value of revolution speed on an input of said transmission on a basis of results of said measuring step; and changing a speed ratio using at least two different algorithms in correspondence with whether or not a value of deviation between said target value and a current actual value is greater than a threshold value; wherein said changing step further comprises: when both an acceleration pedal position variation velocity and an absolute value of said deviation between said target value and the actual value are smaller than predetermined values, said speed ratio is not changed.
Claim 9
Dependent Claim
197 words
In a vehicle transmission system including an operation sensor, a running status sensor, a processor and a memory storing relation data between target speed and data measured by use of said operation sensor and said running status sensor, a speed ratio control method for a continuously variable transmission which transfer inputs from a power source to a drive wheel, comprising the steps of; measuring through said operation and said running status sensors, a driver's operation quantity and a vehicle running status; determining through said processor, by use of said relation data, one of a target value of speed ratio and a target value of revolution speed on an input of said transmission on a basis of results of said measuring step; and changing a speed ratio using at least two different algorithms in correspondence with whether or not a value of deviation between said target value and a current actual value is greater than a threshold value; wherein said changing step further comprises: when both an acceleration pedal position variation velocity and an absolute value of said deviation between said target value and the actual value are smaller than predetermined values, said speed ratio is not changed.
Claim 10
Dependent Claim
143 words
In a vehicle including an operation sensor, a running status sensor, a processing means and a memory storing relation data between target speed and data measured by use of said operation sensor and said running status sensor, a speed ratio control system of a continuously variable transmission which transfers inputs from a power source to a drive wheel, comprising: means for measuring a driver's operation quantity and a vehicle running status; means for determining one of a target value of speed ratio and a target value of revolution speed on an input of said transmission on a basis of results from said means for measuring; and means for changing a speed ratio using at least two different algorithms in correspondence with whether or not a value of deviation between said target value and a current actual value is greater than a threshold value.
Claim 11
Dependent Claim
143 words
In a vehicle including an operation sensor, a running status sensor, a processing means and a memory storing relation data between target speed and data measured by use of said operation sensor and said running status sensor, a speed ratio control system of a continuously variable transmission which transfers inputs from a power source to a drive wheel, comprising: means for measuring a driver's operation quantity and a vehicle running status; means for determining one of a target value of speed ratio and a target value of revolution speed on an input of said transmission on a basis of results from said means for measuring; and means for changing a speed ratio using at least two different algorithms in correspondence with whether or not a value of deviation between said target value and a current actual value is greater than a threshold value.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1999-09-24 | 2000-03-25 | 2000-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-09-24 | 2004-03-25 | 2004-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-09-24 | 2008-03-25 | 2008-09-24 | $7700.00 | Window Closed / Lapsed |