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US 11,105,418 B2Granted
Vehicle
AssigneeToyota Jidosha Kabushiki Kaisha
InventorRyochi Watanabe
Life of this patent
Estimating the term…
Abstract
An ECU determines whether or not a road surface changes from a low μ road surface to a high μ road surface based on image data obtained by a camera sense. When the ECU determines that the accelerator pedal operation amount deceases greatly in a predetermined determination period from a time point at which a drive wheel slip state occurs in a case where the ECU determines that the road surface changes from the low μ road surface to the high μ road surface, it prohibits upshift operation of an automatic transmission over a predetermined period from that time point.
Claims5
A vehicle comprising:
- an automatic transmission configured to:
- achieve selectively one of a first gear stage and a second gear stage which is a higher speed gear stage as compared to the first gear stage;
- and
- transmit a driving force generated by a driving force generation device of said vehicle to drive wheels of said vehicle thorough said achieved gear stage;
- an electronic control unit including a processor and a memory programmed to:
- determine said gear stage to be achieved by said automatic transmission based on a vehicle speed and an accelerator pedal operation amount;
- and
- control said automatic transmission so as to conform said gear stage achieved by said automatic transmission to said determined gear stage;
- and
- a camera that photographs subjects including a road surface in front of said vehicle to thereby obtain image data,
- wherein, said electronic control unit is further programmed to:
- determine whether or not a first condition is satisfied, said first condition being a condition to be satisfied when a drive wheel slip state in which said drive wheels are in slip states is occurring;
- obtain, based on said image data, a first value and a second value,
- said first value correlating with a road surface friction coefficient of a first area which is a first part within said road surface;
- and
- said second value correlating with a road surface friction coefficient of a second area which is a second part within said road surface, said second area located in front of and adjacent to said first area;
- determine whether or not a second condition is satisfied, said second condition being a condition to be satisfied when a difference index value indicative of a degree of a difference between said first value and said second value is equal to or larger than a road surface change determination threshold;
- determine whether or not a third condition is satisfied, said third condition being a condition to be satisfied when said accelerator pedal operation amount decreases by an amount larger than a predetermined return determination threshold in a predetermined determination period starting after it has been determined that said first condition is satisfied;
- and
- control said automatic transmission in such a manner that said automatic transmission does not execute an upshift operation from said first gear stage to said second gear stage in a predetermined upshift prohibition period which starts from a start time point at which an upshift prohibition condition becomes satisfied, said upshift prohibition condition being a condition to be satisfied when it is determined that said second condition is satisfied and said third condition is satisfied.
17 more elements
Dependencies are inferred from the claim text.