Abstract: A method, computer usable medium including a program, and a system for braking a vehicle during brake failure. The method and computer usable medium include the steps of determining a brake force lost corresponding to a failed brake, and determining a brake force reserve corresponding to at least one non-failed brake. At least one commanded brake force is determined based on the brake force lost and the brake force reserve. Then at least one command brake force is applied to the at least one non-failed brake wherein at least one of an undesired yaw moment and a yaw moment rate of change are limited to predetermined values. The system includes a plurality of brake assemblies wherein a commanded brake force is applied to at least one non-failed brake.

Abstract: The absolute roll angle of a vehicle body is estimated by blending two preliminary roll angle estimates based on their frequency so that the blended estimate continuously favors the more accurate of the preliminary roll angle estimates. A first preliminary roll angle estimate based on the measured roll rate is improved by initially compensating the roll rate signal for bias error using roll rate estimates inferred from other measured parameters. And a second preliminary roll angle estimate is determined based on the kinematic relationship among roll angle, lateral acceleration, yaw rate and vehicle speed. The blended estimate of roll angle utilizes a blending coefficient that varies with the frequency of the preliminary roll angle signals, and a blending factor used in the blending coefficient is set to different values depending whether the vehicle is in a steady-state or transient condition.

Abstract: The absolute roll angle of a vehicle body is estimated by blending two preliminary roll angle estimates based on their frequency so that the blended estimate continuously favors the more accurate of the preliminary roll angle estimates. A first preliminary roll angle estimate based on the measured roll rate is improved by initially compensating the measured roll rate for bias error using roll rate estimates inferred from other measured parameters. And a second preliminary roll angle estimate is determined according to the sum of the road bank angle and the relative roll angle. The blended estimate is used to estimate the actual lateral acceleration, the lateral velocity and side-slip angle of the vehicle, which are used in rollover detection and other various other control applications.

Abstract: A method of estimating vehicle inertial parameters for use in a vehicle stability control system including the steps of obtaining measurements of tire normal forces, calculating an estimated total vehicle mass, calculating an estimated mass proportioned between axles, and performing a vehicle stability control calculation using an estimated vehicle inertial parameter. In a second aspect of the method, a method of estimating vehicle inertial parameters using measurements of tire lateral forces.

Abstract: A vehicle stability control system diagnostic strategy, wherein the diagnostic strategy may be adaptively applied based upon the identified maneuver states of the vehicle. The diagnostic architecture contains three vehicle state observers (i.e., models) each based on inputs from only two of the three sensors (yaw rate, lateral acceleration, and hand wheel angle). More particularly, the first observer does not consider lateral acceleration input. The second observer does not consider yaw rate sensor input and the third does not consider hand wheel angle (UWA) sensor input in determining the vehicle state. However, estimated vehicle speed input is used by all the observers. For example, the first observer detects a maneuver state based on yaw rate and HWA and vehicle speed inputs. Then it diagnoses the lateral acceleration sensor failure based on the observer output.

Abstract: A technique for reducing excessive motor vehicle roll angle using a feedforward control comprises a number of steps. Initially, a steering angle and a speed of the-motor vehicle are determined. Next, a lateral acceleration of the vehicle is estimated based on the steering angle and the speed. Then, a lateral acceleration proportional and derivative (PD) term of the estimated lateral acceleration is determined and roll angle reduction is implemented when the lateral acceleration PD term exceeds a first threshold. The roll angle reduction may be achieved through application of a braking force to an outside front wheel of the vehicle. A magnitude of the braking force may be proportional to a difference between the lateral acceleration PD term and the first threshold.

Abstract: A system and a method for determining when to update a surface estimation value indicative of a condition of a roadway surface are provided. The method includes determining a front axle cornering force error value based on a predicted front axle cornering force value and a first front axle cornering force value. The method further includes determining a threshold yaw rate error value based on the front axle cornering force error value. The method further includes indicating that the surface estimation value is to be updated when a yaw rate error value is greater than the threshold yaw rate error value.

Abstract: A system and a method for determining when to update a surface estimation value indicative of a condition of a roadway surface are provided. The method includes determining a front axle cornering force error value based on a predicted front axle cornering force value and a first front axle cornering force value. The method further includes determining a threshold yaw rate error value based on the front axle cornering force error value. The method further includes indicating that the surface estimation value is to be updated when a yaw rate error value is greater than the threshold yaw rate error value.

Abstract: A method for compensating for a lateral force disturbance acting on a vehicle including the steps of estimating a magnitude of the lateral force disturbance, determining whether the magnitude or a rate of change of the magnitude exceeds a predetermined threshold value and, when the predetermined threshold value is exceeded, generating a control signal adapted to at least partially counter the lateral force disturbance.

Abstract: A control system manages yaw-plane motion, while simultaneously comprehending and managing roll motion. The system reduces excessive maneuver-induced roll motion by properly shaping yaw-plane motion, which may include increasing yaw damping and/or decreasing a yaw gain, under various conditions, to avoid excessive excitation of roll dynamics.

Abstract: A method for collision avoidance using automated braking and steering comprising: determining an actual distance to an obstacle in a path of a vehicle; determining a relative velocity between the obstacle and the vehicle; determining a first distance sufficient to avoid collision by braking only; determining a second distance sufficient to avoid collision by combined braking and steering around the obstacle. The method also includes: applying braking if at least one of, the first distance exceeds the actual distance and the first distance is within a selected threshold of the actual distance. If the actual distance exceeds the second distance and a lane change is permitted, steering control to affect a lane change is applied.

Abstract: A method, computer usable medium including a program, and a system for braking a vehicle during brake failure. The method and computer usable medium include the steps of determining a brake force lost corresponding to a failed brake, and determining a brake force reserve corresponding to at least one non-failed brake. At least one command brake force is determined based on the brake force lost and the brake force reserve. The at least one command brake force is applied to the at least one non-failed brake wherein at least one of an undesired yaw moment and a yaw moment rate of change are limited to predetermined values. The system includes a plurality of brake assemblies wherein a command brake force is applied to at least one non-failed brake.

Abstract: The invention provides a method, a computer usable medium including a program, and a system for operating a vehicle control system. A plurality of measured vehicle variables is determined. At least one suspension force is determined based on at least one of the determined measured vehicle variables. At least one tire vertical force is determined based on the at least one determined suspension force and at least one of the determined measured vehicle variables. At least one tire longitudinal force is determined based on at least one of the determined measured vehicle variables. At least one axle lateral force is determined based on at least one of the determined measured vehicle variables. At least one tire lateral force is determined based on the at least one determined axle lateral force and the at least one determined tire vertical force.

Abstract: In an unified control of a plurality of active chassis systems a role of each chassis system in applying a corrective net force and a corrective moment to a vehicle is determined. In determining the roles, control influence coefficients and a control authority of each active chassis system is determined. An activation status of each active chassis system based on the control influence coefficients and the control authority is subsequently determined.

Abstract: A method for collision avoidance using automated braking and steering comprising: determining an actual distance to an obstacle in a path of a vehicle; determining a relative velocity between the obstacle and the vehicle; determining a first distance sufficient to avoid collision by braking only; determining a second distance sufficient to avoid collision by combined braking and steering around the obstacle. The method also includes: applying braking if at least one of, the first distance exceeds the actual distance and the first distance is within a selected threshold of the actual distance. If the actual distance exceeds the second distance and a lane change is permitted, steering control to affect a lane change is applied.

Abstract: The invention provides a method, a computer usable medium including a program, and a system for determining a vehicle payload condition. The method and computer usable medium include the steps of determining a first payload-state parameter, a second payload-state parameter, and at least one roll value. A first differential is determined based on the first payload-state parameter and the second payload-state parameter. A second differential is determined based on the first payload-state parameter and the roll value. A multiplier is determined. A payload estimate is determined based on the first payload differential, the second payload differential, and the multiplier. The system includes means for achieving the method steps of the invention.

Abstract: In an unified control of a plurality of active chassis systems a role of each chassis system in applying a corrective net force and a corrective moment to a vehicle is determined. In determining the roles, control influence coefficients and a control authority of each active chassis system is determined. An activation status of each active chassis system based on the control influence coefficients and the control authority is subsequently determined.

Abstract: A dynamic side-to-side braking method is disclosed. First, when the vehicle is in a combined braking and cornering maneuver, a desired braking force among tires of a vehicle is determined. Second, a brake force distribution of the desired braking force among the tires is determined. The brake force distribution is approximately proportional to a normal force distribution among the tires during the combined braking and cornering maneuver by the vehicle. When the vehicle excludes an active steering system, front or rear, the brake force distribution is determined as a function of a feedback correction to counterbalance a portion of a yaw moment experienced by the vehicle during the combined braking and cornering maneuver. When the vehicle includes an active steering system, front or rear, a steering correction is determined to counterbalance a portion of the yaw moment experienced by the vehicle during the combined braking and cornering maneuver.

Abstract: The invention provides a method and computer usable medium, including a program, for vehicle stability control. A rear axle cornering stiffness coefficient in a linear handling range is determined. A first understeer coefficient in a linear handling range is determined. A desired lateral acceleration is determined based on the first understeer coefficient. A second understeer coefficient is determined based on a limited magnitude of the desired lateral acceleration. A desired yaw rate is determined based on the second understeer coefficient. A desired lateral velocity is determined based on the desired yaw rate and the rear axle cornering stiffness coefficient.

Abstract: A method and computer usable medium, including a program, for vehicle stability control. A rear axle cornering stiffness coefficient in a linear handling range is determined. A first understeer coefficient in a linear handling range is determined. A desired lateral acceleration is determined based on the first understeer coefficient. A second understeer coefficient is determined based on a limited magnitude of the desired lateral acceleration. A desired yaw rate is determined based on the second understeer coefficient. A desired lateral velocity is determined based on the desired yaw rate and the rear axle cornering stiffness coefficient.