A method for operating a coefficient of friction database includes receiving information, that is output by transmitting vehicles and that includes coefficient of friction data describing an ascertained coefficient of friction potential of a road segment, location data describing a geometrical position of the road segment, and time data describing an instant of ascertainment of the coefficient of friction data or describing the coefficient of friction potential, and storing the information in a coefficient of friction database from which the data is then retrievable by receiving vehicles.

A method for operating a coefficient of friction database includes receiving information, that is output by transmitting vehicles and that includes coefficient of friction data describing an ascertained coefficient of friction potential of a road segment, location data describing a geometrical position of the road segment, and time data describing an instant of ascertainment of the coefficient of friction data or describing the coefficient of friction potential, and storing the information in a coefficient of friction database from which the data is then retrievable by receiving vehicles.

A vehicle driving assist apparatus executes a vehicle collision prevention control when a target object distance from a vehicle to a target object is equal to or smaller than a predetermined distance. The apparatus acquires the target object distance on the basis of a position of the target object in a camera image taken by a camera and a height of the camera in a situation that a movable load of the vehicle is a maximum load capacity.

A trailer backup assist system for a vehicle reversing a trailer is provided herein. The system includes a brake system and a steering system of the vehicle. A controller is configured to output a brake torque request to the brake system and a steering command to the steering system, wherein the brake torque request and the steering command are each based at least in part on a trailer mass.

Systems and methods for an autonomous vehicle are provided. In one aspect, an autonomous vehicle includes a perception sensor and a processor configured to: receive detected roadway conditions data including roadway grade data from the perception sensor, retrieve mapped data having grade data, and determine that the roadway has a grade based on the detected roadway grade data and the retrieved roadway grade data. The processor can be further configured to, in response to determining that the roadway has a grade, determine that the grade of the roadway is greater than or equal to a predetermined high grade value and less than a predetermined grade limit, and in response to determining that the grade of the roadway is greater than or equal to the predetermined high grade value and less than the predetermined grade limit, operate the autonomous vehicle to change lane to a right-most lane.

A vehicle includes a center differential device and an air pressure controller. The center differential device includes a first output shaft coupled to front wheels and a second output shaft coupled to rear wheels. The center differential device is configured to perform differential operation between the first output shaft and the second output shaft and to limit the differential operation between the first output shaft and the second output shaft. The air pressure controller is configured to control air pressure of one or more tires of the front wheels and the rear wheels such that an average rotational speed of the front wheels and an average rotational speed of the rear wheels are equal to each other.

An end point speed at an end point of inertial travel that a vehicle is controlled to perform in a short section l.sub.i is calculated using a weight, a start point speed, slopes, and a horizontal distance, based on a change in energy of the vehicle or an acceleration of the vehicle in the short section. In a case where the calculated end point speed is within a speed range, the vehicle is controlled to perform inertial travel in the short section. In this way, the speed of the vehicle in a case where the vehicle is controlled to perform inertial travel can be accurately calculated and the vehicle can be prevented from deviating from a set speed range at an early stage even when controlled to perform inertial travel, thereby increasing the distance traveled by inertial travel and effectively increasing fuel economy.

An end point speed at an end point of inertial travel that a vehicle is controlled to perform in a short section l.sub.i is calculated using a weight, a start point speed, slopes, and a horizontal distance, based on a change in energy of the vehicle or an acceleration of the vehicle in the short section. In a case where the calculated end point speed is within a speed range, the vehicle is controlled to perform inertial travel in the short section. In this way, the speed of the vehicle in a case where the vehicle is controlled to perform inertial travel can be accurately calculated and the vehicle can be prevented from deviating from a set speed range at an early stage even when controlled to perform inertial travel, thereby increasing the distance traveled by inertial travel and effectively increasing fuel economy.

A driving assistance method for controlling an own vehicle by a controller in such a way that the own vehicle travels along a target travel trajectory includes: acquiring level-difference information of a level difference existing along a lane in which the own vehicle travels; and when, from the level-difference information, determining that the own vehicle is to climb over the level difference, generating the target travel trajectory in such a way that a level-difference climbing-over angle, which is an angle formed by the level difference and the target travel trajectory, is larger than a threshold value.

A driving assistance method for controlling an own vehicle by a controller in such a way that the own vehicle travels along a target travel trajectory includes: acquiring level-difference information of a level difference existing along a lane in which the own vehicle travels; and when, from the level-difference information, determining that the own vehicle is to climb over the level difference, generating the target travel trajectory in such a way that a level-difference climbing-over angle, which is an angle formed by the level difference and the target travel trajectory, is larger than a threshold value.