Vehicle rollover detection and mitigation using rollover index
First Claim
1. A method for controlling a vehicle to prevent rollover, comprising the steps of:
- measuring lateral acceleration of a vehicle;
measuring one of a vehicle roll rate and vehicle suspension displacements;
deriving an estimated roll angle from the measured lateral acceleration and the measured one of the vehicle roll rate and the vehicle suspension displacements;
deriving a roll angle index from comparison of at least the measured lateral acceleration, the measured one of the vehicle roll rate and the vehicle suspension displacements and the estimated roll angle, wherein a magnitude of the roll angle index provides an indication of a rollover danger and a sign of the roll angle index provides a direction of impending rollover; and
controlling at least one of vehicle braking and vehicle steering to reduce the possibility of rollover responsive to the roll control angle index.
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Accused Products
Abstract
A method and apparatus for determining likelihood of rollover of a vehicle and/or mitigating rollover of the vehicle is responsive to measured vehicle lateral acceleration and a measured one of vehicle roll rate and vehicle suspension displacements to derive estimates of roll angle and roll rate. First, preliminary, estimates of roll angle and roll rate are derived and used as pseudo-measurements in a dynamic, closed loop observer equation which represents a model of the vehicle in a first roll mode for roll angles small compared to a reference value indicating two wheel lift-off and a second roll mode for roll angles at least near a reference value indicating two wheel lift-off. The observer equation has parameters and gains with values for each mode stored as a function of roll angle index derived from measurements and pseudo-measured values. The observer equation produces second, improved values or roll angle and roll rate together indicating the likelihood of vehicle rollover. Rollover mitigating controls for brakes, active front steer, and/or active rear steer are also disclosed.
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Citations
26 Claims
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1. A method for controlling a vehicle to prevent rollover, comprising the steps of:
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measuring lateral acceleration of a vehicle; measuring one of a vehicle roll rate and vehicle suspension displacements; deriving an estimated roll angle from the measured lateral acceleration and the measured one of the vehicle roll rate and the vehicle suspension displacements; deriving a roll angle index from comparison of at least the measured lateral acceleration, the measured one of the vehicle roll rate and the vehicle suspension displacements and the estimated roll angle, wherein a magnitude of the roll angle index provides an indication of a rollover danger and a sign of the roll angle index provides a direction of impending rollover; and controlling at least one of vehicle braking and vehicle steering to reduce the possibility of rollover responsive to the roll control angle index. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A system for controlling a vehicle to prevent rollover, comprising:
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a plurality of vehicle suspension displacement sensors; a vehicle lateral acceleration sensor; a vehicle roll rate sensor; a vehicle brake subsystem; a vehicle steering subsystem; and a processor coupled to the vehicle suspension displacement sensors, the vehicle lateral acceleration sensor, the vehicle roll rate sensor, the vehicle brake subsystem and the vehicle steering subsystem, the processor executing code for instructing the processor to perform the steps of; measuring lateral acceleration of the vehicle as provided by the lateral acceleration sensor; measuring one of a vehicle roll rate as provided by the roll rate sensor and vehicle suspension displacements as provided by the vehicle suspension displacement sensors; deriving an estimated roll angle from the measured lateral acceleration and the measured one of the vehicle roll rate and the vehicle suspension displacements; deriving a roll control term from at least the measured lateral acceleration, the measured one of the vehicle roll rate and the vehicle suspension displacements and the estimated roll angle, wherein a magnitude of the roll control term provides an indication of a rollover danger and a sign of the roll control term provides a direction of impending rollover; and controlling at least one of vehicle brake subsystem and vehicle steering subsystem to reduce the possibility of rollover responsive to the roll control term. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A method for controlling a vehicle to prevent rollover, comprising the steps of:
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measuring lateral acceleration of a vehicle; measuring one of a vehicle roll rate and vehicle suspension displacements; deriving an estimated roll angle from the measured lateral acceleration and the measured one of the vehicle roll rate and the vehicle suspension displacements; deriving a roll angle index from a comparison of at least the measured lateral acceleration, the measured one of the vehicle roll rate and the vehicle suspension displacements and the estimated roll angle, wherein a magnitude of the roll angle index provides an indication of a rollover danger and a sign of the roll angle index provides a direction of impending rollover; and controlling at least one of vehicle braking and vehicle steering to reduce the possibility of rollover responsive to the roll angle index when the magnitude of the roll angle index is greater than a predetermined value. - View Dependent Claims (22, 23, 24, 25, 26)
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Specification