Abstract: A tire-based system and method for estimating road surface friction includes a model-based longitudinal stiffness estimation generator using tire-based parameter inputs and vehicle-based parameter inputs; an actual longitudinal stiffness estimation generator using real-time vehicle-based parameter inputs; and a tire road friction estimation generator for deriving a tire road friction estimation from a comparative analysis between the actual longitudinal stiffness estimation and the model-based longitudinal stiffness estimation. A road surface classifier algorithm is employed to generate a road surface type analysis from the road friction estimation, an ambient air temperature measurement, and an ambient air moisture measurement.

Abstract: Estimating a load bearing on a vehicle tire includes an inflation pressure measuring sensor for measuring tire inflation pressure and generating a measured tire inflation pressure signal; a deformation measuring sensor mounted in a tire region of the vehicle tire, the deformation measuring sensor in the form of a piezoelectric bending sensor generating a deformation signal estimating a length of a tire contact patch length as the senor rolls through a tire footprint. Tire rolling speed is estimated from the deformation signal and a peak to peak amplitude variation within the deformation signal is detected and measured. An artificial neural network receives the tire rolling speed estimation, the contact patch length estimation, the amplitude variation within the deformation signal, and the measured inflation pressure of the tire. The artificial neural network adaptively interprets the input data and generates an output load estimation based thereon.

Abstract: A tire wear state estimation system includes as inputs an axle force estimation, a measured tire inflation pressure; a tire load estimation; a tire cornering stiffness estimation; and a tire identification by which a specific tire-based correlation model correlates tire inflation pressure, the tire load estimation, the tire cornering stiffness estimation, and the vehicle-based sensor axle force estimation.

Abstract: A tire inner liner-based estimation system and method for a vehicle includes a tire pressure sensor mounted to a vehicle tire for detecting a measured tire air cavity pressure; a vehicle speed sensor mounted to provide a measured vehicle speed; a tire identification device mounted to the tire for conveying a tire identification; a tire inner liner deflection sensor mounted to detect and measure a loaded inner liner radius. An estimation of an inner liner-based parameter is iteratively made from the measured tire pressure and the loaded inner liner radius measurement.

Abstract: The invention relates generally to tire monitoring systems for collecting measured tire parameter data during vehicle operation and, more particularly, to a system and method for estimating tire wear state based upon such measurements.

Abstract: A slip angle estimation includes a tire having one or more first and second strain sensor(s) affixed to opposite respective first and second tire sidewalls. The sensors measure a tire strain in their respective sidewalls and generate a sidewall strain signal indicative of strain present within the tire sidewalls. A slip angle estimation is made by estimating the difference in the signal slope of the sensors in the opposite sidewalls. A load estimation is further made for the tire from the inner and outer sidewall strain signals and the load estimation is used in the slip angle estimation.

Abstract: A road friction coefficient estimation system and method uses tire load estimation sensors attached to a vehicle's tires. Tire load and slip angle for each tire are estimated from sensor data. From vehicle CAN bus sensors, vehicle acceleration and yaw rate operational parameters are obtained and a dynamic observer model calculates lateral and longitudinal force estimates on each of the tires. An individual wheel force estimation is calculated on each tire from the lateral and longitudinal force estimates for each tire. From the dynamic slip angle estimation on each tire and the individual wheel force estimation on each of the tires, a model-based friction estimation is made.

Abstract: A tire wear state estimation system includes as inputs an axle force estimation, a measured tire inflation pressure; a tire load estimation; a tire cornering stiffness estimation; and a tire identification by which a specific tire-based correlation model correlates tire inflation pressure, the tire load estimation, the tire cornering stiffness estimation, and the vehicle-based sensor axle force estimation.

Abstract: A tire wear state estimation system includes a tire pressure measuring device affixed to a vehicle tire for measuring tire inflation pressure and generating tire inflation pressure data; tire torsional mode measuring means for measuring tire torsional mode frequency and generating tire torsional mode frequency data; and tire identification means for generating tire-specific torsional mode coefficients using tire-specific identification data. A tire wear estimation is made based upon the tire inflation pressure data, the torsional mode frequency data, and the tire identification derived torsional mode coefficients.

Abstract: The invention relates generally to tire monitoring systems for collecting measured tire parameter data during vehicle operation and, more particularly, to a system and method for estimating tire wear state based upon such measurements.

Abstract: A dynamic slip angle estimation system and method uses measured vehicle acceleration and yaw rate parameters in estimating a tire slip angle. From load sensor(s) mounted to the vehicle tire, a tire static load estimation is made and a tire slip angle is calculated at low frequency. The vehicle center of gravity longitudinal position and yaw moment of inertia is estimated from the static load on the vehicle tires. An observer calculates tire axle forces based on the vehicle acceleration and yaw rate. From the tire axle force estimations, the vehicle moment of inertia and vehicle center of gravity longitudinal position estimate and a low frequency direct measurement of the tire slip angle, a dynamic tire slip angle calculation is made.

Abstract: A dynamic load estimation system is provided including: a vehicle load bearing tire; at least one tire sensor mounted to the tire, the sensor operable to measure a tire deformation of the one tire and generate a raw load-indicating signal conveying measured deformation data; road roughness estimation means for determining a road roughness estimation; filtering means for filtering the measured deformation data by the road roughness estimation; and load estimation means for estimating an estimated load on the one tire from filtered measured deformation data. A road profile estimate is fused with the static load estimate in order to obtain an instantaneous tire load estimate.

Abstract: A system and method estimating a vehicle tire load includes a tire static load estimator estimating a static tire load using a tire attached TPMS sensor; a Kalman filter based tire deflection estimator estimating tire vertical deflection; a load variation estimator estimating the instantaneous load variation by using the tire vertical deflection information; and an output tire load estimator calculating an output load estimation mathematically by fusing the static tire load with the instantaneous load variation information. The tire deflection estimator includes a chassis accelerometer measuring a chassis vertical acceleration; and a hub accelerometer measuring a wheel hub vertical acceleration of the tire. A linear filter model receives as inputs the chassis vertical acceleration and the wheel hub vertical acceleration.

Abstract: A dynamic load estimation system and method is provided, the system including a tire supporting a vehicle; a vehicle-mounted acceleration sensor for determining a vehicle lateral acceleration and a vehicle longitudinal acceleration; a roll angle calculating model for determining a vehicle roll angle; a roll rate calculating model for determining a vehicle roll rate; a static normal load calculation model for calculating a measured static normal load; and a dynamic tire load estimation model for calculating an estimated dynamic load on the tire from the measured static normal load, the vehicle roll angle, the vehicle roll rate, the vehicle lateral acceleration and the vehicle longitudinal acceleration.

Abstract: A dynamic slip angle estimation system and method uses measured vehicle acceleration and yaw rate parameters in estimating a tire slip angle. From load sensor(s) mounted to the vehicle tire, a tire static load estimation is made and a tire slip angle is calculated at low frequency. The vehicle center of gravity longitudinal position and yaw moment of inertia is estimated from the static load on the vehicle tires. An observer calculates tire axle forces based on the vehicle acceleration and yaw rate. From the tire axle force estimations, the vehicle moment of inertia and vehicle center of gravity longitudinal position estimate and a low frequency direct measurement of the tire slip angle, a dynamic tire slip angle calculation is made.

Abstract: A dynamic load estimation system is provided including: a vehicle load bearing tire; at least one tire sensor mounted to the tire, the sensor operable to measure a tire deformation of the one tire and generate a raw load-indicating signal conveying measured deformation data; road roughness estimation means for determining a road roughness estimation; filtering means for filtering the measured deformation data by the road roughness estimation; and load estimation means for estimating an estimated load on the one tire from filtered measured deformation data.

Abstract: A slip angle estimation includes a tire having one or more first and second strain sensor(s) affixed to opposite respective first and second tire sidewalls. The sensors measure a tire strain in their respective sidewalls and generate a sidewall strain signal indicative of strain present within the tire sidewalls. A slip angle estimation is made by estimating the difference in the signal slope of the sensors in the opposite sidewalls. A load estimation is further made for the tire from the inner and outer sidewall strain signals and the load estimation is used in the slip angle estimation.

Abstract: A load estimation system and method for estimating vehicle load includes a tire rotation counter for generating a rotation count from rotation of a tire; apparatus for measuring distance travelled by the vehicle; an effective radius calculator for calculating effective radius of the tire from the distance travelled and the rotation count; and a load estimation calculator for calculating the load carried by the vehicle tire from the effective radius of the tire. A center of gravity height estimation may be made from an estimated total load carried by the tires supporting the vehicle pursuant to an estimation of effective radius for each tire and a calculated load carried by each tire from respective effective radii.

Abstract: A system and method of estimating a load bearing on a vehicle tire includes an inflation pressure measuring sensor attached to the tire for measuring a tire cavity inflation pressure level; and one or more piezofilm deformation measuring sensors mounted to one or both of the tire sidewalls. The deformation measuring sensor generates within the tire footprint a deformation signal having signal power level indicative of a level of sidewall deformation within the footprint contact patch. Power-to-load maps adjusted for tire inflation pressure are generated and stored for the tire, the maps correlating a range of load levels to a range of signal power levels whereby operatively enabling a load level to be identified for each signal power level on an inflation pressure adjusted basis.

Abstract: A system and method of estimating a load bearing on a vehicle tire includes an inflation pressure measuring sensor attached to the tire for measuring a tire cavity inflation pressure level; and one or more piezofilm deformation measuring sensors mounted to one or both of the tire sidewalls. The deformation measuring sensor generates within the tire footprint a deformation signal having signal power level indicative of a level of sidewall deformation within the footprint contact patch. Power-to-load maps adjusted for tire inflation pressure are generated and stored for the tire, the maps correlating a range of load levels to a range of signal power levels whereby operatively enabling a load level to be identified for each signal power level on an inflation pressure adjusted basis.