An apparatus for determining bicycle pedaling may include a sensor that detects the angular velocity and position of a drivetrain or rear sprocket assembly of the bicycle and a processor that is configured to compare the detected values against values indicative of at least one pedaling state. The apparatus may be configured to be housed within a component of the bicycle, such as within a hollow opening of the spindle or crank axle. The apparatus also may include a wireless transmitter to communicate with another component, such as a suspension controller.

An apparatus for determining bicycle pedaling may include a sensor that detects the angular velocity and position of a drivetrain or rear sprocket assembly of the bicycle and a processor that is configured to compare the detected values against values indicative of at least one pedaling state. The apparatus may be configured to be housed within a component of the bicycle, such as within a hollow opening of the spindle or crank axle. The apparatus also may include a wireless transmitter to communicate with another component, such as a suspension controller.

An accelerometer arrangement and method are described for determining accelerations of an inground tool. First and second triaxial accelerometers are supported such that a normal sensing axis of the first triaxial accelerometer is at least generally orthogonal to the normal sensing axis of the second triaxial accelerometer for determining the accelerations along the three orthogonal axes based on a combination of sensing axis outputs from one or both of the triaxial accelerometers. A weaker sensing axis of one triaxial accelerometer can be supported at least approximately normal to a weaker sensing axis of another triaxial accelerometer such that the weaker axes are not used. The triaxial accelerometers can be supported such that one axis of one accelerometer can be redundant with respect to another axis of another accelerometer. One triaxial accelerometer can be mounted on a tilted plane with respect to another triaxial accelerometer.

An accelerometer arrangement and method are described for determining accelerations of an inground tool. First and second triaxial accelerometers are supported such that a normal sensing axis of the first triaxial accelerometer is at least generally orthogonal to the normal sensing axis of the second triaxial accelerometer for determining the accelerations along the three orthogonal axes based on a combination of sensing axis outputs from one or both of the triaxial accelerometers. A weaker sensing axis of one triaxial accelerometer can be supported at least approximately normal to a weaker sensing axis of another triaxial accelerometer such that the weaker axes are not used. The triaxial accelerometers can be supported such that one axis of one accelerometer can be redundant with respect to another axis of another accelerometer. One triaxial accelerometer can be mounted on a tilted plane with respect to another triaxial accelerometer.

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, limiting a bias error in a manner of limiting a bias error component of an angular velocity around a reference vector in error information, and correcting the predicted posture information of the object based on the error information, the reference vector, and an output of a reference observation sensor.

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, limiting a bias error in a manner of limiting a bias error component of an angular velocity around a reference vector in error information, and correcting the predicted posture information of the object based on the error information, the reference vector, and an output of a reference observation sensor.

A device of or attached to a roller body determines a rotational frequency of the roller body (or other object) rotating about an axis of rotation includes an acceleration sensor that detects an acceleration signal of an acceleration in a first direction extending in a radial or tangential direction to the axis of rotation of the roller body; and an electronic processing unit and configured to low-pass and high-pass, particularly adaptively high-pass filter, the detected acceleration signal, perform a derivation, with respect to time, of the filtered signal, optimize the signal with a subsequent absolute-amount generation and with moving averaging, and ascertain a frequency of the filtered acceleration signal, which corresponds to the rotational frequency of the roller body.

A device of or attached to a roller body determines a rotational frequency of the roller body (or other object) rotating about an axis of rotation includes an acceleration sensor that detects an acceleration signal of an acceleration in a first direction extending in a radial or tangential direction to the axis of rotation of the roller body; and an electronic processing unit and configured to low-pass and high-pass, particularly adaptively high-pass filter, the detected acceleration signal, perform a derivation, with respect to time, of the filtered signal, optimize the signal with a subsequent absolute-amount generation and with moving averaging, and ascertain a frequency of the filtered acceleration signal, which corresponds to the rotational frequency of the roller body.

Methods and systems are provided for estimation of a road roughness index (RRI) and adjusting vehicle operation based on the metric. In one example, a method may include estimating the RRI as a function of a pitch energy and a roll energy of the vehicle travelling on the road. In response to the RRI being higher than a threshold, engine operation such as EGR flow rate may be adjusted.

Methods and systems are provided for estimation of a road roughness index (RRI) and adjusting vehicle operation based on the metric. In one example, a method may include estimating the RRI as a function of a pitch energy and a roll energy of the vehicle travelling on the road. In response to the RRI being higher than a threshold, engine operation such as EGR flow rate may be adjusted.