Yaw moment control apparatus for vehicle
First Claim
1. A yaw moment control apparatus for a vehicle comprising:
- a left hydraulic pump connected to and rotated by a left wheel;
a right hydraulic pump connected to and rotated by a right wheel;
a first oil passage which connects a discharge port of said left hydraulic pump and a suction port of said right hydraulic pump;
a second oil passage which connects a discharge port of said right hydraulic pump and a suction port of said left hydraulic pump;
a first variable throttle valve provided between said first oil passage and a tank;
a second variable throttle valve provided between said second oil passage and said tank;
first displacement control means for increasing a discharge displacement of said left hydraulic pump according to a closure of said first variable throttle valve;
second displacement control means for increasing a discharge displacement of said right hydraulic pump according to a closure of said second variable throttle valve; and
roll angle control means for rolling a vehicle body in one of leftward and rightward directions by using a hydraulic pressure produced by said left hydraulic pump during the closure of said first variable throttle valve, and in the other of the leftward and rightward directions by using a hydraulic pressure produced by said right hydraulic pump during the closure of said second variable throttle valve.
1 Assignment
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Accused Products
Abstract
A left hydraulic pump connected to a left wheel and a right hydraulic pump connected to a right wheel of a vehicle are connected by a first oil passage and a second oil passage to constitute a closed circuit, and first and second variable throttle valves are provided between the first and second oil passages and the tank. Either one of the first and second variable throttle valves is throttled to cause the first and second hydraulic pumps to produce a braking force and a driving force, respectively, thereby controlling a yaw moment. At the same time, when either one of left and right wheel suspensions expands, the roll rigidity of the vehicle increases or decreases to vary the cornering forces of the wheels, thereby producing a yaw moment which assists in the yaw moment produced by the first and second hydraulic pumps.
68 Citations
12 Claims
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1. A yaw moment control apparatus for a vehicle comprising:
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a left hydraulic pump connected to and rotated by a left wheel; a right hydraulic pump connected to and rotated by a right wheel; a first oil passage which connects a discharge port of said left hydraulic pump and a suction port of said right hydraulic pump; a second oil passage which connects a discharge port of said right hydraulic pump and a suction port of said left hydraulic pump; a first variable throttle valve provided between said first oil passage and a tank; a second variable throttle valve provided between said second oil passage and said tank; first displacement control means for increasing a discharge displacement of said left hydraulic pump according to a closure of said first variable throttle valve; second displacement control means for increasing a discharge displacement of said right hydraulic pump according to a closure of said second variable throttle valve; and roll angle control means for rolling a vehicle body in one of leftward and rightward directions by using a hydraulic pressure produced by said left hydraulic pump during the closure of said first variable throttle valve, and in the other of the leftward and rightward directions by using a hydraulic pressure produced by said right hydraulic pump during the closure of said second variable throttle valve. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method of effecting yaw moment control in a vehicle including a yaw rate sensor, a plurality of wheel speed sensors, a steering angle sensor, and left and right hydraulic pumps connected to and rotated by left and right wheels, respectively, comprising the step of:
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detecting a real yaw rate from an output of the yaw rate sensor; calculating a reference yaw rate based on a steering angle detected by the steering angle sensor and a vehicle speed detected by the plurality of wheel speed sensors; comparing the reference yaw rate with the actual yaw rate, and, if the reference yaw rate and the actual yaw rate are not equal; controlling oil pressures to the left and right hydraulic pumps respectively, to produce a driving force on one of the right and left wheels and a braking force on the other of the right and left wheels to tend to equalize the reference yaw rate and the actual yaw rate. - View Dependent Claims (11, 12)
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Specification