Friction detecting device for vehicles
First Claim
1. A vehicle steering control system comprising running condition detecting means for detecting a running condition of a vehicle including a lateral acceleration acting on a gravity center of the vehicle, steering detecting means for detecting steering angle of front and rear wheels of the vehicle, vehicle speed detecting means for detecting a vehicle speed, memory means for storing stability factors of the vehicle including a vehicle weight, respective distances between the gravity center and front and rear axles, cornering powers acting on the front and rear wheels at a standard condition and a yawing moment of inertia, and calculating means for calculating a frictional coefficient μ
- of a road surface on which the vehicle is running by employing a following formula;
space="preserve" listing-type="equation">μ
=[V{m(a.sup.2 K.sub.F +b.sup.2 K.sub.R) +IK}s-mV.sup.2 (aK.sub.F -bK.sub.R)]
space="preserve" listing-type="equation"> a.sub.Y /2cK.sub.F K.sub.R {V(bδ
.sub.F +aδ
.sub.R)s+V.sup.2 (δ
.sub.F -δ
.sub.R)-ca.sub.Y } (1)wherein aY is the lateral acceleration acting on the gravity center of the vehicle, δ
F is the steering angle of the front wheels, δ
R is the steering angle of the rear wheels, V is the vehicle speed, m is the vehicle weight, a is the distance between the gravity center of the vehicle and the front axle, b is the distance between the gravity center of the vehicle and the rear axle, KF, KR are the cornering powers for the front and rear wheels at the standard condition, I is the yawing moment of inertia of the vehicle, c=a+b, K=KF +KR and s is a laplacian operator, and control means for controlling the steering angle for the rear wheels in accordance with said frictional coefficient μ
provided by the calculating means.
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Accused Products
Abstract
A friction detecting device comprising running condition detector for detecting a running condition of a vehicle including a lateral acceleration acting on a gravity center of the vehicle, steering angle detector for detecting steering angle of front and rear wheels of the vehicle, vehicle speed sensor, memory for storing stability factors of the vehicle including a vehicle weight, respective distances between the gravity center and front and rear axles, cornering powers acting on the front and rear wheels at a standard condition and a yawing moment of inertia, control unit for obtaining a frictional coefficient μ of a road surface on which the vehicle is running by employing a following formula;
μ=[V{m(a.sup.2 K.sub.F +b.sup.2 K.sub.R)+IK}s-mV.sup.2 (aK.sub.F
-bKR)]
a.sub.y /2cK.sub.F K.sub.R {V(bδ.sub.F +aδ.sub.R)s+V.sup.2
(δF -δR)-cay }
wherein ay is the lateral acceleration acting on the gravity center of the vehicle, δF is the steering angle of the front wheels, δR is the steering angle of the rear wheels, V is the vehicle speed, m is the vehicle weight, a is the distance between the gravity center of the vehicle and the front axle, b is the distance between the gravity center of the vehicle and the rear axle, KF, KR are the cornering powers for the front and rear wheels at the standard condition, I is the yawing moment of inertia of the vehicle, c=a+b, K=KF +KR and s is a laplacian operator.
72 Citations
13 Claims
-
1. A vehicle steering control system comprising running condition detecting means for detecting a running condition of a vehicle including a lateral acceleration acting on a gravity center of the vehicle, steering detecting means for detecting steering angle of front and rear wheels of the vehicle, vehicle speed detecting means for detecting a vehicle speed, memory means for storing stability factors of the vehicle including a vehicle weight, respective distances between the gravity center and front and rear axles, cornering powers acting on the front and rear wheels at a standard condition and a yawing moment of inertia, and calculating means for calculating a frictional coefficient μ
- of a road surface on which the vehicle is running by employing a following formula;
space="preserve" listing-type="equation">μ
=[V{m(a.sup.2 K.sub.F +b.sup.2 K.sub.R) +IK}s-mV.sup.2 (aK.sub.F -bK.sub.R)]
space="preserve" listing-type="equation"> a.sub.Y /2cK.sub.F K.sub.R {V(bδ
.sub.F +aδ
.sub.R)s+V.sup.2 (δ
.sub.F -δ
.sub.R)-ca.sub.Y } (1)wherein aY is the lateral acceleration acting on the gravity center of the vehicle, δ
F is the steering angle of the front wheels, δ
R is the steering angle of the rear wheels, V is the vehicle speed, m is the vehicle weight, a is the distance between the gravity center of the vehicle and the front axle, b is the distance between the gravity center of the vehicle and the rear axle, KF, KR are the cornering powers for the front and rear wheels at the standard condition, I is the yawing moment of inertia of the vehicle, c=a+b, K=KF +KR and s is a laplacian operator, and control means for controlling the steering angle for the rear wheels in accordance with said frictional coefficient μ
provided by the calculating means. - View Dependent Claims (2, 3, 4, 5, 6)
- of a road surface on which the vehicle is running by employing a following formula;
-
7. A vehicle steering control system comprising running condition detecting means for detecting a running condition of a vehicle including a lateral acceleration acting on a gravity center of the vehicle, steering detecting means for detecting steering angle of front and rear wheels of the vehicle, vehicle speed detecting means for detecting a vehicle speed, memory means for storing stability factors of the vehicle including a vehicle weight, respective distances between the gravity center and front and rear axles, cornering powers acting on the front and rear wheels at a standard condition and a yawing moment of inertia, and differentiating means for receiving signals from the running condition detecting means and steering detecting means and calculating differential values of values detected by the running condition detecting means and the steering detecting means, and calculating means for calculating a frictional coefficient μ
- of a road surface on which the vehicle is running by employing a following formula;
space="preserve" listing-type="equation">μ
=[V{m(a.sup.2 K.sub.F +b.sup.2 K.sub.R) +IK}s-mV.sup.2 (aK.sub.F -bK.sub.R)]
space="preserve" listing-type="equation"> a.sub.Y /2cK.sub.F K.sub.R {V(bδ
.sub.F +aδ
.sub.R)s+V.sup.2 (δ
.sub.F -δ
.sub.R)-ca.sub.Y } (2)wherein aY is the lateral acceleration acting on the gravity center of the vehicle, δ
F is the steering angle of the front wheels, δ
R is the steering angle of the rear wheels, V is the vehicle speed, m is the vehicle weight, a is the distance between the gravity center of the vehicle and the front axle, b is the distance between the gravity center of the vehicle and the rear axle, KF, KR are the cornering powers for the front and rear wheels at the standard condition, I is the yawing moment of inertia of the vehicle, c=a+b, K=KF +KR and s is a laplacian operator, and control means for controlling the steering angle for the rear wheels in accordance with said frictional coefficient μ
.
- of a road surface on which the vehicle is running by employing a following formula;
-
8. A vehicle steering control system comprising running condition detecting means for detecting a running condition of a vehicle including a lateral acceleration acting on a gravity center of the vehicle, steering detecting means for detecting steering angle of front and rear wheels of the vehicle, vehicle speed detecting means for detecting a vehicle speed, memory means for storing stability factors of the vehicle including a vehicle weight, respective distances between the gravity center and front and rear axles, cornering powers acting on the front and rear wheels at a standard condition and a yawing moment of inertia, differentiating means for receiving signals from the running condition detecting means and steering detecting means and calculating differential values of values detected by the running condition detecting means and the steering detecting means, operating condition detecting means for detecting an operating condition of the vehicle, first calculating means for calculating a frictional coefficient μ
- of a road surface on which the vehicle is running by employing a following formula when the operating condition of the vehicle is in a normal condition;
space="preserve" listing-type="equation">μ
=[V{m(a.sup.2 K.sub.F +b.sup.2 K.sub.R) +IK}s-mV.sup.2 (aK.sub.F -bK.sub.R)]
space="preserve" listing-type="equation"> a.sub.Y /2cK.sub.F K.sub.R {V(bδ
.sub.F +aδ
.sub.R)s+V.sup.2 (δ
.sub.F -δ
.sub.R)-ca.sub.Y } (1)and second calculating means for calculating a fractional coefficient μ
of a road surface on which the vehicle is running by employing a following formula when the operating condition of the vehicle is in a specific condition;
space="preserve" listing-type="equation">μ
=[V{m(a.sup.2 K.sub.F +b.sup.2 K.sub.R) +IK}s-mV.sup.2 (aK.sub.F -bK.sub.R
space="preserve" listing-type="equation"> a.sub.Y /2cK.sub.F K.sub.R {V(bδ
.sub.F +aδ
.sub.R)s+V.sup.2 (δ
.sub.F -δ
.sub.R)-ca.sub.Y } (2)wherein aY is the lateral acceleration acting on the gravity center of the vehicle, δ
F is the steering angle of the front wheels, δ
R is the steering angle of the rear wheels, V is the vehicle speed, m is the vehicle weight, a is the distance between the gravity center of the vehicle and the front axle, b is the distance between the gravity center of the vehicle and the rear axle, KF, KR are the cornering powers for the front and rear wheels at the standard condition, I is the yawing moment of inertia of the vehicle, c=a+b, K=KF +KR and s is a laplacian operator, and control means for controlling the steering angle for the rear wheels in accordance with the frictional coefficient μ
obtained through the above formula (1) or (2). - View Dependent Claims (9, 10, 11, 12)
- of a road surface on which the vehicle is running by employing a following formula when the operating condition of the vehicle is in a normal condition;
-
13. A vehicle steering control system comprising running condition detecting means for detecting a ruining condition of a vehicle including a lateral acceleration acting on a gravity center of the vehicle, steering detecting means for detecting steering angle of front and rear wheels of the vehicle, vehicle speed detecting means for detecting a vehicle speed, memory means for storing stability factors of the vehicle including a vehicle weight, respective distances between the gravity center and front and rear axles, cornering powers acting on the front and rear wheels at a standard condition and a yawing moment of inertia, compensating means for applying a time delay factor employing a time constant and calculating means for calculating a frictional coefficient μ
- of a road surface on which the vehicle is running by employing a following formula;
space="preserve" listing-type="equation">μ
=[V{m(a.sup.2 K.sub.F +b.sup.2 K.sub.R) +IK}s-mV.sup.2 (aK.sub.F -bK.sub.R)]
space="preserve" listing-type="equation"> a.sub.Y /2cK.sub.F K.sub.R {V(bδ
.sub.F +aδ
.sub.R)s+V.sup.2 (δ
.sub.F -δ
.sub.R)-ca.sub.Y } (1)wherein aY is the lateral acceleration acting on the gravity center of the vehicle, Θ
F is the steering angle of the front wheels, Θ
R is the steering angle of the rear wheels, V is the vehicle speed, m is the vehicle weight, a is the distance between the gravity center of the vehicle and the front axle, b is the distance between the gravity center of the vehicle and the rear axle, KF, KR are the cornering powers for the front and rear wheels at the standard condition, I is the yawing moment of inertia of the vehicle, c=a+b, K=KF +KR and s is a laplacian operator, δ
F =DΘ
F, δ
R =DΘ
R τ
is the time constant and D=1/(1+τ
s), and control means for controlling the steering angle for the rear wheels in accordance with said frictional coefficient μ
obtained through the formula (1).
- of a road surface on which the vehicle is running by employing a following formula;
Specification