Tire grip level estimation apparatus and method
First Claim
1. A tire grip level estimation apparatus comprising:
- self-aligning torque acquisition means which estimates or detects self-aligning torque generated on the grounding surface of wheels;
lateral direction quantity-of-state computation means which computes lateral direction quantity of state generated in said wheels;
front-rear direction quantity-of-state computation means which computes front-rear direction quantity of state generated in said wheels;
self-aligning model value computation means which computes self-aligning torque model value on the basis of said lateral direction quantity of state and one or more tire parameters;
ratio computation means which computes self-aligning ratio, which is the ratio between the self-aligning torque estimated or detected by said self-aligning torque acquisition means and the self-aligning torque model value computed by said self-aligning model value computation means; and
grip level estimation means which estimates a grip level of the tires on the basis of said self-aligning ratio and said front-rear direction quantity of state from a predetermined map representing the relationship between the self-aligning ratio, the front-rear direction quantity of state, and the grip level, whereinsaid front-rear direction quantity of state is front-rear force or quotient obtained by dividing the front-rear force by the cornering power.
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Accused Products
Abstract
An SAT estimator 16 estimates the SAT generated between the road surface and the tire. A slip angle arithmetic unit 18 estimates the front wheel slip angle. A lateral force detector 180 computes the lateral force generated in the wheels. An SAT model value arithmetic unit 22 computes the SAT model value from the slip angle estimate and the lateral force value. A front-rear direction quantity-of-state arithmetic unit 240 computes the front-rear direction quantity of state generated in the wheels. A grip level estimator 26 estimates the grip level from the SAT estimated by the SAT estimator 16, the SAT model value computed by the SAT model value arithmetic unit 22, and the front-rear direction quantity of state estimated by the front-rear direction quantity-of-state arithmetic unit 240.
28 Citations
17 Claims
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1. A tire grip level estimation apparatus comprising:
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self-aligning torque acquisition means which estimates or detects self-aligning torque generated on the grounding surface of wheels; lateral direction quantity-of-state computation means which computes lateral direction quantity of state generated in said wheels; front-rear direction quantity-of-state computation means which computes front-rear direction quantity of state generated in said wheels; self-aligning model value computation means which computes self-aligning torque model value on the basis of said lateral direction quantity of state and one or more tire parameters; ratio computation means which computes self-aligning ratio, which is the ratio between the self-aligning torque estimated or detected by said self-aligning torque acquisition means and the self-aligning torque model value computed by said self-aligning model value computation means; and grip level estimation means which estimates a grip level of the tires on the basis of said self-aligning ratio and said front-rear direction quantity of state from a predetermined map representing the relationship between the self-aligning ratio, the front-rear direction quantity of state, and the grip level, wherein said front-rear direction quantity of state is front-rear force or quotient obtained by dividing the front-rear force by the cornering power. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A tire grip level estimation apparatus comprising:
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self-aligning torque acquisition means which estimates or detects self-aligning torque generated on the grounding surface of wheels; lateral direction quantity-of-state computation means which computes lateral direction quantity of state generated in said wheels; self-aligning model value computation means which computes a self-aligning torque model value on the basis of said lateral direction quantity of state, front-rear direction quantity of state, and tire parameter; ratio computation means which computes a self-aligning ratio, which is the ratio between the self-aligning torque estimated or detected by said self-aligning torque acquisition means and the self-aligning torque model value computed by said self-aligning model value computation means; and grip level estimation means which estimates a grip level of the tires on the basis of said self-aligning ratio from a predetermined map representing the relationship between the self-aligning ratio and the grip level. - View Dependent Claims (8)
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9. A tire grip level estimation apparatus comprising:
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self-aligning torque acquisition means which estimates or detects self-aligning torque generated on the grounding surface of wheels; slip angle computation means which computes slip angle generated in said wheels; self-aligning torque model value computation means which computes self-aligning torque model value on the basis of the slip angle computed by said slip angle computation means, and grounding length and stiffness of said wheels; self-aligning torque ratio computation means which computes self-aligning torque ratio, which is the ratio between the self-aligning torque estimated by said self-aligning torque acquisition means and the self-aligning torque model value computed by said self-aligning model value computation means; braking/driving force estimation means which estimates the braking/driving force generated in the wheels for braking/driving a vehicle; and grip level estimation means which estimates a grip level for said wheels on the basis of the self-aligning torque ratio computed by said self-aligning torque ratio computation means and the braking/driving force estimated by said braking/driving force estimation means from a predetermined map representing the relationship between the self-aligning ratio, the braking/driving force, and the grip level. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17)
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Specification