Two wheeled vehicle braking system using a target slippage ratio for control
First Claim
1. A system for obtaining a target slippage ratio for stable braking of a vehicle having two wheels, comprising:
- a pair of vehicle speed sensors disposed respectively on the wheels of said vehicle for detecting respective peripheral velocities of said wheels;
slippage ratio calculation means for calculating a slippage ratio between said wheels and a road surface based on signals output from said vehicle speed sensors;
friction coefficient calculating means for calculating a coefficient of friction between at least one of said wheels and a road surface based on a detected acceleration of said vehicle and said slippage ratio;
target slippage ratio setting means for setting a target slippage ratio for said at least one wheel based on said coefficient of friction;
first correction coefficient setting means for detecting a rate of change in said coefficient of friction and setting a first correction coefficient based on said rate of change;
target slippage ratio correcting means for multiplying the target slippage ratio by first correction coefficient thereby to provide a corrected target slippage ratio; and
means for applying a braking force to said at least one wheel until said corrected target slippage ratio is reached, and for controlling said braking force so as to maintain said corrected target slippage ratio.
1 Assignment
0 Petitions
Accused Products
Abstract
A brake control system for obtaining the optimal slippage ratio for stable braking of a vehicle, has a friction coefficient detecting device, a target slippage ratio setting device, a correction coefficient setting device and a target slippage ratio correcting device. The friction coefficient detecting device detects the coefficient of friction between each of wheels and a road surface. The target slippage ratio setting device sets up a target slippage ratio based on the coefficient of friction. The correction coefficient setting device detects the rate of change in the coefficient of friction and sets a first correction coefficient for calculating the target slippage ratio based on the rate of change in the coefficient of friction. The target slippage ratio correcting device multiplies the target slippage ratio by the first correction coefficient thereby to correct the target slippage ratio. Thus, the vehicle can be smoothly driven.
26 Citations
11 Claims
-
1. A system for obtaining a target slippage ratio for stable braking of a vehicle having two wheels, comprising:
-
a pair of vehicle speed sensors disposed respectively on the wheels of said vehicle for detecting respective peripheral velocities of said wheels; slippage ratio calculation means for calculating a slippage ratio between said wheels and a road surface based on signals output from said vehicle speed sensors; friction coefficient calculating means for calculating a coefficient of friction between at least one of said wheels and a road surface based on a detected acceleration of said vehicle and said slippage ratio; target slippage ratio setting means for setting a target slippage ratio for said at least one wheel based on said coefficient of friction; first correction coefficient setting means for detecting a rate of change in said coefficient of friction and setting a first correction coefficient based on said rate of change; target slippage ratio correcting means for multiplying the target slippage ratio by first correction coefficient thereby to provide a corrected target slippage ratio; and means for applying a braking force to said at least one wheel until said corrected target slippage ratio is reached, and for controlling said braking force so as to maintain said corrected target slippage ratio. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A device for estimating the velocity of a vehicle based on a peripheral velocity of each wheel and on a detected acceleration of the vehicle, comprising:
-
a plurality of vehicle speed sensors disposed respectively on each said wheel of said vehicle for detecting a rotational speed of each said wheel; accelerator means disposed on said vehicle for controlling an acceleration of the vehicle; wheel velocity calculating means for calculating the peripheral velocity of each said wheel based on signals output from said vehicle speed sensors; vehicle acceleration detecting means for detecting the detected acceleration of the vehicle; acceleration determining means for determining, based on a signal from said vehicle acceleration detecting means, whether the vehicle is in an acceleration state; and estimated vehicle velocity calculating means for comparing the peripheral velocity of each said wheel and a present estimated velocity of the vehicle when it is determined by said acceleration determining means that the vehicle is not in an acceleration state, successively updating the estimated velocity of the vehicle while said vehicle is accelerating or decelerating based on a result of the comparison, and successively updating the present estimated velocity of the vehicle while said vehicle is accelerated when it is decided that the vehicle is in an acceleration state.
-
-
9. A device for calculating a banking angle of a vehicle having a front wheel and a rear wheel, comprising:
-
a first vehicle speed sensor disposed on said front wheel for detecting a peripheral velocity of said front wheel; a second vehicle speed sensor disposed on said rear wheel for detecting a peripheral velocity of said rear wheel; means for calculating respective slip ratios of said front wheel and said rear wheel and a road surface based on signals output from said first and second vehicle speed sensors; accelerator means disposed on said vehicle for controlling an acceleration of the vehicle; front wheel velocity calculating means for calculating the peripheral velocity of the front wheel based on signals output from said first vehicle speed sensor; rear wheel velocity calculating means for calculating the peripheral velocity of the rear wheel based on signals output from said second vehicle speed sensor; vehicle acceleration detecting means for detecting an acceleration of the vehicle; vehicle velocity estimating means for estimating a velocity of the vehicle based on said peripheral velocity of each said front and rear wheel and the detected acceleration of the vehicle; first banking angle storing means for storing the relationship between (i) a difference in the peripheral velocities of the front and rear wheel and (ii) the banking angle with respect to the peripheral velocity of the front wheel; means for calculating said banking angle when the estimated velocity of the vehicle reaches a predetermined value based on said peripheral velocity of the front wheel and said difference in the respective peripheral velocities of the front and rear wheels; means for correcting a target slip ratio of at least one of said front and rear wheels based on a calculated banking angle; and means for applying a braking force to at least one of said front and rear wheels until the corrected target slip ratio is reached, and for controlling said braking force so as to maintain said corrected target slip ratio. - View Dependent Claims (10, 11)
-
Specification