Device and method for evaluating low-μ road and power distribution control device for four-wheel drive vehicles
First Claim
Patent Images
1. A low-μ
- road evaluation device for controlling the distribution of power between the front and rear wheels of a four wheel drive vehicle comprising;
slip rate calculating means for calculating a slip rate between a wheel of a vehicle and a road surface;
low-μ
information magnitude calculating means for calculating a low-μ
information magnitude associated with a friction coefficient of said road surface, based on both of said slip rate and an acceleration operation magnitude derived from a throttle setting sensor in said vehicle;
comparison evaluating means for comparing between said calculated low-μ
information magnitude and a first preset threshold value;
adding means for adding a value based on said low-μ
information magnitude to a counter when said comparison evaluating means determines that said low-μ
information magnitude exceeds said first preset threshold value;
subtracting means for subtracting a predetermined value from the counter added to by said adding means when said comparison evaluating means determines that said low-μ
information magnitude does not exceed said first preset threshold value; and
low-μ
road evaluating means for determining that there is a low-μ
road when the counter calculated by said adding means or said subtracting means exceeds a second preset threshold value.
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Abstract
A power distribution control device 42 calculates a low-μ information magnitude, associated with the friction coefficient of the road surface, based on the slip rate and the vehicle acceleration operation magnitude. If the low-μ information magnitude exceeds an addition evaluation threshold, the power distribution control device 42 adds the low-μ information magnitude. If the low-μ information magnitude does not exceed the addition evaluation threshold, the power distribution control device 42 subtracts a constant K from a counter. The power distribution control device 42 makes evaluates a road to have a low-μ when the counter exceeds a low-μ evaluation threshold.
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Citations
10 Claims
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1. A low-μ
- road evaluation device for controlling the distribution of power between the front and rear wheels of a four wheel drive vehicle comprising;
slip rate calculating means for calculating a slip rate between a wheel of a vehicle and a road surface; low-μ
information magnitude calculating means for calculating a low-μ
information magnitude associated with a friction coefficient of said road surface, based on both of said slip rate and an acceleration operation magnitude derived from a throttle setting sensor in said vehicle;comparison evaluating means for comparing between said calculated low-μ
information magnitude and a first preset threshold value;adding means for adding a value based on said low-μ
information magnitude to a counter when said comparison evaluating means determines that said low-μ
information magnitude exceeds said first preset threshold value;subtracting means for subtracting a predetermined value from the counter added to by said adding means when said comparison evaluating means determines that said low-μ
information magnitude does not exceed said first preset threshold value; andlow-μ
road evaluating means for determining that there is a low-μ
road when the counter calculated by said adding means or said subtracting means exceeds a second preset threshold value. - View Dependent Claims (2, 3, 4)
- road evaluation device for controlling the distribution of power between the front and rear wheels of a four wheel drive vehicle comprising;
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5. A power distribution control device for a four-wheel drive vehicle, comprising:
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controlling means for controlling a coupling force that transfers power generated by an internal combustion engine to front and rear wheels, based on driving conditions of said vehicle; slip rate calculating means for calculating a slip rate between a wheel of a vehicle and a road surface; low-μ
information magnitude calculating means for calculating a low-μ
information magnitude associated with a friction coefficient of said road surface, based on both of said slip rate and an acceleration operation magnitude derived from a throttle setting sensor in said vehicle;comparison evaluating means for comparing between said calculated low-μ
information magnitude and a first preset threshold value;adding means for adding a value based on said low-μ
information magnitude to a counter when said comparison evaluating means determines that said low-μ
information magnitude exceeds said first preset threshold value;subtracting means for subtracting a predetermined value from the counter added to by said adding means when said comparison evaluating means determines that said low-μ
information magnitude does not exceed said first preset threshold value; andlow-μ
road evaluating means for determining that there is a low-μ
road when the counter calculated by said adding means or said subtracting means exceeds a second preset threshold value,wherein said controlling means performs four-wheel drive torque distribution when said low-μ
road evaluation means evaluates a road as having a low-μ
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6. A method of evaluating a low-μ
- road, comprising the steps of;
calculating a slip rate between a wheel and a road surface; calculating a low-μ
information magnitude associated with a friction coefficient of said road surface, based on both of said slip rate and an acceleration value derived from a throttle setting sensor in said vehicle;comparing said low-μ
information magnitude with a first preset threshold value;adding a value based on said low-μ
information value to a counter when said low-μ
information magnitude exceeds said first preset threshold value;subtracting a predetermined value from the counter when said low-μ
information magnitude does not exceed said first preset threshold value; anddetermining that there is a low-μ
road when the counter is evaluated to exceed a second preset threshold value. - View Dependent Claims (7, 8, 9, 10)
- road, comprising the steps of;
Specification