A device for calibrating a laser level includes a base platform, a target, and an image recognition device. The base platform is configured to support the laser level that is to be mounted on the base platform at a first position. The target is arranged at a second position of the base platform and configured to receive a laser. The image recognition device is configured to obtain images of lasers projected on the target before and after the laser level rotates a first angle, determine, based on an image recognition result of the images, positions of the lasers emitted by the laser level to determine a deviation distance, and determine whether the laser level needs to be calibrated based on the deviation distance. The deviation distance is determined by position data of the first position and the second position, and the first angle.

A device for calibrating a laser level includes a base platform, a target, and an image recognition device. The base platform is configured to support the laser level that is to be mounted on the base platform at a first position. The target is arranged at a second position of the base platform and configured to receive a laser. The image recognition device is configured to obtain images of lasers projected on the target before and after the laser level rotates a first angle, determine, based on an image recognition result of the images, positions of the lasers emitted by the laser level to determine a deviation distance, and determine whether the laser level needs to be calibrated based on the deviation distance. The deviation distance is determined by position data of the first position and the second position, and the first angle.

A method for calibrating a laser level. includes arranging the laser level and a detector on a same horizontal plane to cause the laser level to be at a detected position, setting the laser level to be in a dot-sweep mode or a fan-sweep mode, when the detector detects the first laser beam for calibration emitted by the laser level, generating first position information by the detector, when the laser level rotates to a first rotation angle, rotating a laser projection direction of the laser level relative to the laser level along the opposite direction by a first rotation angle to cause the detector to detect the second laser beam for calibration emitted by the laser level to generate second position information, and determining whether the laser level needs to be calibrated based on the first position information and the second position information.

A method for calibrating a laser level. includes arranging the laser level and a detector on a same horizontal plane to cause the laser level to be at a detected position, setting the laser level to be in a dot-sweep mode or a fan-sweep mode, when the detector detects the first laser beam for calibration emitted by the laser level, generating first position information by the detector, when the laser level rotates to a first rotation angle, rotating a laser projection direction of the laser level relative to the laser level along the opposite direction by a first rotation angle to cause the detector to detect the second laser beam for calibration emitted by the laser level to generate second position information, and determining whether the laser level needs to be calibrated based on the first position information and the second position information.

A heavy goods vehicle includes a displacement calculator that calculates a displacement by multiplying an arc length per unit rotation angle of the outer circumference of a specified tire by the first physical quantity, a vehicle position estimator that estimates a vehicle position using the displacement, and a memory that stores a correlation between a second physical quantity corresponding to a loading weight and an arc length per predetermined rotation angle at the outer circumference of the specified tire. The displacement calculator refers to the correlation to calculate a current arc length per unit rotation angle at the outer circumference of the specified tire from the second physical quantity corresponding to the loading weight, and calculates the displacement by multiplying the first physical quantity detected by the rotation amount detector by the current arc length per unit rotation angle.

A method involves identifying multiple calibration values and corresponding calibration confidence values of an initial calibration dataset in which one or more calibration values were derived using an atmospheric pressure measurement from a barometric air pressure sensor of a mobile device. A calibration metric is determined for each calibration value. One or more of the calibration values are filtered out from the initial calibration dataset based on the calibration metric to generate a filtered calibration dataset. A filtered calibration value is determined using the filtered calibration dataset. The barometric air pressure sensor of the mobile device is calibrated using the filtered calibration value.

A method involves identifying multiple calibration values and corresponding calibration confidence values of an initial calibration dataset in which one or more calibration values were derived using an atmospheric pressure measurement from a barometric air pressure sensor of a mobile device. A calibration metric is determined for each calibration value. One or more of the calibration values are filtered out from the initial calibration dataset based on the calibration metric to generate a filtered calibration dataset. A filtered calibration value is determined using the filtered calibration dataset. The barometric air pressure sensor of the mobile device is calibrated using the filtered calibration value.

An alert indicates that a situation conducive to calibrating a barometric pressure sensor of the user device might have occurred. In response, calibration data is collected for calibrating the barometric pressure sensor. The calibration data is used to perform a calibration process and generate a calibration value for the barometric pressure sensor.

Systems and methods for operating an engine that includes an exhaust system with a differential pressure sensor are described. In one example, output of the differential pressure sensor is compared to output of a barometric pressure sensor to determine whether or not the barometric pressure sensor is degraded. The output of the differential pressure sensor may be monitored while the engine is rotated without being fueled.

Systems and methods for operating an engine that includes an exhaust system with a differential pressure sensor are described. In one example, output of the differential pressure sensor is compared to output of a barometric pressure sensor to determine whether or not the barometric pressure sensor is degraded. The output of the differential pressure sensor may be monitored while the engine is rotated without being fueled.