According to the method of estimating a maximum road friction coefficient, artificial braking or driving-related control is conducted and a maximum road friction coefficient is estimated based on a difference in wheel speeds between front and rear wheels, compensated for slip of tires.

Methods and systems are provided for a vehicle system. In one example, a method may include ascertaining a functional relationship between the driving resistance and the velocity v.sub.veh of a motor vehicle comprising an electrical machine as a torque source for the drive and a storage device for electrical energy.

An information processing system includes one or more vehicles, and a server communicable with the one or more vehicles. The vehicle acquires an image obtained by imaging a road on which a host vehicle is located. The vehicle or the server determines a degree of difficulty in traveling on the road due to snow cover from the image. The server stores the degree of difficulty in traveling for each of one or more roads, and provides information to a client by using the stored degree of difficulty in traveling for each of one or more roads.

The invention relates to a method for determining a parameter indicative of a road capability of a road segment (16) supporting a vehicle (10). The vehicle (10) comprises a sensor (18) adapted to generate an information package on the basis of signals (20, 22) reflected from the surface of a portion of the road segment (16) in front of the vehicle (10), as seen in an intended direction of travel of the vehicle (10). The vehicle (10) further comprises a plurality of ground engaging members (12, 14). The method comprises: —determining a reference content measure indicative of the information content of an information package supplied by the sensor (18) at a reference time instant (T1); —comparing the reference content measure to a previous content measure indicative of the information content of an information package supplied by the sensor (18) at a previous time instant (T0), the previous time instant (T0) occurring before the reference time instant (T1); —upon detecting that a difference between the reference content measure and the previous content measure is outside a predetermined tolerance range, allowing the execution of a determination procedure for determining the parameter indicative of the road capability of the road segment (16) supporting the vehicle (10); —upon detecting that the difference between the reference content measure and the previous content measure is within the predetermined tolerance range, not allowing the execution of the determination procedure, and —wherein the determination procedure comprises modifying the operation of one or more of the ground engaging members (12, 14).

A device for estimating a friction coefficient between a road surface and an automotive tire through determination of a steering torque during a steering maneuver of a slow-rolling or stationary vehicle includes a computer configured for constructing a brush model for a description of the steering torque across a contact patch between the tire and road surface. The steering torque is a torque acting on a steering axis required to overcome resistance to tire twisting on the road surface at a wheel velocity and a steering rate. The steering torque depends on a tire brush vertical load distribution and relative motion of tire brushes and the road surface. The device further includes sensors for measuring the wheel velocity and the steering rate and mechanism for measurements or estimation of the steering torque. The friction coefficient is estimated based on the measurements or estimation of the steering torque and the brush model.

A travel control system for a vehicle provided with a drive source, a wheel having a wheel body connected to the drive source via a power transmission member and a tire mounted on the wheel body, and a braking device for braking the wheel includes: an estimation unit configured to estimate a tire torsional stiffness and a road surface friction coefficient based on at least the rotation speed of the drive source, the rotation speed of the wheel body, the vehicle body speed, and the torque applied to the wheel body; and a control unit configured to control at least one of the drive source and the braking device such that the tire does not exceed an adhesion limit derived from the tire torsional stiffness and the road surface friction coefficient.

A method for operating a motor vehicle, with a drive device for providing a driving torque as well as a detection device for detecting at least one other motor vehicle up ahead. An automatic length guidance of the motor vehicle is carried out. In this case, it is provided that, in the framework of the length guidance, a distance of the motor vehicle from the other motor vehicle is adjusted to a nominal distance. The nominal distance corresponds to a distance setting at constant distance, and starting from the distance setting, it is increased in the event of a distance change resulting from a positive acceleration of the other motor vehicle, and it is reduced in the event of a distance change resulting from a negative acceleration of the other motor vehicle.

Systems and methods for managing environmental conditions for an autonomous vehicle are disclosed. In one aspect, an autonomous vehicle includes a perception sensor configured to generate perception data indicative of a condition of the environment, a network communication transceiver configured to communicate with an oversight system and an external weather condition source, a non-transitory computer readable medium, and a processor. The processor is configured to: receive the perception data from the at least one perception sensor, receive an indication of current weather conditions from the external weather condition source, determine a current environmental condition severity level from a plurality of severity levels based on the perception data and the indication of current weather conditions, modify one or more driving parameters that that govern a range of actions that can be autonomously executed by the autonomous vehicle, and navigate the autonomous vehicle based on the modified driving parameters.

This disclosure relates to a system and method for transitioning vehicle control between autonomous operation and manual operation. The system includes sensors configured to generate output signals conveying information related to the vehicle and its operation. During autonomous vehicle operation, the system gauges the level of responsiveness of a vehicle operator through challenges and corresponding responses. The system determines when to present a challenge to the vehicle operator based on internal and external factors. If necessary, the system will transition from an autonomous operation mode to a manual operation mode.

An autonomous vehicle can comprise winter servicing equipment, such as a snowplow, salt spreader, etc. A controller can be supported by the vehicle and can be operatively coupled thereto. The controller can be configured to control the vehicle to autonomously move through an area along a planned route to effect servicing (e.g., snow removal or remediation) of the area. For example, the controller can be configured to discretize the area into a plurality of cells and to determine a quantity of snow in each cell. The route through the area can be planned by the controller based at least in part on simulated movements of the snow quantities in the cells.