In order to detect a road surface condition, a road surface condition estimation device extracts a detection signal of a portion that detects vibration in a tire tangential direction in a vibration detection and power generation unit which is in a ground contact section, for example, a vibration power generation element. In this case, it is identified that the vibration detection and power generation unit is in the ground contact section, based on whether a centrifugal force acting on the vibration detection and power generation unit is generated, or not, and it is identified that a time when no centrifugal force is generated is in the ground contact section. As a result, even if a pulse level of an output voltage of the vibration detection generation unit changes according to a traveling speed of the vehicle, the ground contact section can be accurately identified.

A road surface condition estimation device extracts a detection signal of a vibration power generation element during a ground contact section to detect a road surface condition. A threshold used for determination of the ground contact section is variable according to a traveling speed of a vehicle. As a result, even if a pulse level of an output voltage of the vibration power generation element changes according to the traveling speed of the vehicle, the threshold corresponding to the change can be set. The ground contact section is determined with the use of the above thresholds, thereby being capable of performing the determination with high accuracy. Therefore, the road surface condition can be detected with high accuracy based on the ground contact section determined with high accuracy.

A posture estimation method includes calculating a posture change amount of an object based on an output of an angular velocity sensor, predicting posture information of the object by using the posture change amount, adjusting error information in a manner of determining whether or not the output of the angular velocity sensor is within an effective range and, when it is determined that the output of the angular velocity sensor is not within the effective range, increasing a posture error component in error information and reducing a correlation component between the posture error component and an error component other than the posture error component in the error information, and correcting the predicted posture information of the object based on the error information.

A system and method for computationally estimating a tire normal force for use in vehicle antilock braking, adaptive cruise control, and traction and stability control by correcting measured accelerations with respect to the estimated road angles. The system and method are operative to measure an acceleration at three points on a sprung mass of the vehicle and estimate a tire normal force of a tire in response to the three acceleration measurements as an input to the vehicle controller.

A system includes a driver monitor system configured to receive information about driver operation, a relationship table comprising information about an expected relationship between driver operation and a preload force, and a driver controller configured to control a driver in response to the information about driver operation and according to the relationship table. A method of managing a preload force includes providing a first component, providing a second component for compression against the first component, operating a driver to move the first component into contact with the second component, monitoring an operation of the driver, and determining an expected preload force in response to the operation of the driver.

An operator feedback system of a vehicle includes an inertial measurement unit (IMU) and control circuitry. The inertial measurement unit (IMU) is integrated in one or more components of the vehicle. The IMU is configured to measure one or more acceleration parameters of the one or more components along one or more axes of the IMU. The control circuitry is configured to compare the one or more measured acceleration parameters to one or more preset limiting acceleration parameters. Further, the control circuitry is configured to notify an operator of the vehicle based on the measured one or more acceleration parameters exceeding the one or more preset limiting acceleration parameters.

An example vehicle system includes a sensor and a processing device. The sensor is configured to identify a first location and a second location. The processing device is programmed to estimate a plurality of energy usages. Each energy usage is based at least in part on a speed of a host vehicle at the first location. The processing device is further programmed to select one of the plurality of energy usages as a target useable energy and control the host vehicle in accordance with the speed associated with the target useable energy.

A microcontroller-based method and apparatus are described for measuring motions signals (301) with a plurality of inertial sensors (302-304) contained within a device package housing and validating (420) a first measured motion signal (e.g., .sub.X) by generating at least a first estimated value .sub.X for the first motion signal (e.g., 419) based on at least a second measured motion signal (e.g., A.sub.Y) and for comparing the first estimated value for the first motion signal (419) to the first measured motion signal .sub.X in order to validate the first measured motion signal .sub.X.

In order to detect a road surface condition, a road surface condition estimation device extracts a detection signal of a portion that detects vibration in a tire tangential direction in a vibration detection and power generation unit which is in a ground contact section, for example, a vibration power generation element. In this case, it is identified that the vibration detection and power generation unit is in the ground contact section, based on whether a centrifugal force acting on the vibration detection and power generation unit is generated, or not, and it is identified that a time when no centrifugal force is generated is in the ground contact section. As a result, even if a pulse level of an output voltage of the vibration detection generation unit changes according to a traveling speed of the vehicle, the ground contact section can be accurately identified.

A road surface condition estimation device extracts a detection signal of a vibration power generation element during a ground contact section to detect a road surface condition. A threshold used for determination of the ground contact section is variable according to a traveling speed of a vehicle. As a result, even if a pulse level of an output voltage of the vibration power generation element changes according to the traveling speed of the vehicle, the threshold corresponding to the change can be set. The ground contact section is determined with the use of the above thresholds, thereby being capable of performing the determination with high accuracy. Therefore, the road surface condition can be detected with high accuracy based on the ground contact section determined with high accuracy.