A method determines a roadway condition using steering actuators, wherein at least two steering actuators are arranged on each vehicle wheel. Measurement variables of the first and second steering actuators are sensed. The sensed measurement variables of the two steering actuators are compared with one another and, an inhomogeneity signal is determined from the deviation between the sensed measurement variables of the two steering actuators. If the inhomogeneity signal lies within a tolerance range, a homogeneous roadway condition exists. If the inhomogeneity signal lies outside the tolerance range, an inhomogeneous roadway condition exists.

The invention relates to a method of controlling a heavy-duty vehicle in a slope when the vehicle has come to a standstill due to service brakes of the vehicle having applied a service brake force, the method comprising determining a total brake force required for maintaining the vehicle at standstill, activating at least one park brake for providing a park brake force, gradually increasing the park brake force, and, while the park brake force is gradually increased, gradually reducing the service brake force while maintaining the sum of the service brake force and the park brake force at least equal to the determined total brake force.

Systems and methods are provided for generating data indicative of a friction associated with a driving surface, and for using friction data as part of controlling autonomous vehicle operations. In one example, a computing system can detect an event including at least one of an acceleration, a deceleration, or a stop associated with an autonomous vehicle and obtain, in response to detecting the event, operational data associated with the autonomous vehicle during the event. The computing system can determine, based at least in part on the operational data, data indicative of a friction associated with a surface upon which the autonomous vehicle is traveling during the event. The computing system can control the autonomous vehicle based at least in part on the data indicative of the friction associated with the surface.

A charge potential distributed over a vehicle body resulting from the contact, separation, and friction between a tire and a road surface is detected by a detecting unit provided with a sensing electrode that is disposed on the external surface of the vehicle body, a reference electrode that is disposed apart from the external surface of the vehicle body with a space therebetween, and a sensor amplifier that senses a potential between the sensing electrode and the reference electrode as a signal and amplifies the signal. And the amplitude of the charge potential detected by the detecting unit is monitored by a data processing unit, thereby making it possible to accurately identify not only the state of the road surface but also an internal pressure state of the tire, a wear state of the tire, and the like during vehicular travel.

A control device for a regenerative braking system having control electronics, the control electronics being designed, in consideration of at least one provided first variable with respect to a utilized coefficient of friction occurring in each case at the at least one wheel which may be regeneratively braked, to determine at least one preset variable with respect to at least one hydraulic minimum braking torque to be exerted on the at least one wheel which may be regeneratively braked, and, in consideration of at least the at least one determined preset variable, to determine the at least one setpoint variable.

A road surface friction coefficient estimation apparatus for a vehicle includes: a first estimator; a second estimator; and a third estimator. The first estimator estimates a first road surface friction coefficient on a basis of a vehicle information acquired from the vehicle. The second estimator estimates a second road surface friction coefficient on a basis of an external information acquired from an outside of the vehicle. The third estimator estimates a road surface friction coefficient from the first road surface friction coefficient and the second road surface friction coefficient on a basis of a first reliability degree and a second reliability degree, the first reliability degree indicating a reliability of the first road surface friction coefficient, the second reliability degree indicating a reliability of the second road surface friction coefficient.

A road surface information collection device includes a first sampling unit that samples acceleration sensor's detection results with a first sampling cycle to obtain first sampling data, a position calculator that calculates an acceleration sensor's rotational position based on changes in first sampling data, a second sampling unit that is activated based on a condition that the acceleration sensor is positioned within a first predetermined range including a back side of a point on the tire in contact with the ground, and that samples detection results of the acceleration sensor with a second sampling cycle shorter than first sampling cycle to obtain second sampling data as the road surface information, a speed calculator that detects a rotation speed of the tire based on changes in the first sampling data, and a first predetermined range determination unit that changes the first predetermined range in accordance with the rotation speed of tire.

A method is disclosed for controlling brake forces of a working machine, the working machine including a frame and two front wheels and two rear wheels mounted to the frame, the working machine further including a front wheel brake arranged to brake at least one of the front wheels, and a rear wheel brake arranged to brake at least one of the rear wheels, the front wheel brake being controllable independently of the rear wheel brake, and vice versa, the working machine further including an implement connected to the frame so as to be movable in relation to the frame. The method includes determining a position of the implement in relation to the frame, and distributing the brake forces between the front and rear wheel brakes at least partly based on the determined implement position.

A system for controlling a vehicle by jointly estimating a state of a vehicle and a function of a tire friction of a vehicle traveling on a road uses a particle filter maintaining a set of particles. Each particle includes an estimation of a state of the vehicle, an estimation of probability density function (pdf) of the tire friction function, and a weight indicative of a probability of the particle. The system executes the particle filter to update the particles based on a motion model and a measurement model of the vehicle, control commands moving the vehicle and measurements of the state where the vehicle moved according to the control commands. A control command is generated based on the motion of the vehicle, the weighted combinations of the state of the vehicle and the pdf of the tire friction function weighted according corresponding weights of the particles.

A method is disclosed for improving the permissiveness of a vehicle designed to operate within an operational design domain (“ODD”) where the vehicle has an autonomous vehicle control system capable of collecting sensor data. The method, which can be incorporated into a system or into instructions placed on storage media, includes partitioning the ODD into subsets (“micro-ODDs”) that relate to different operational situations and creating safety envelopes for those subsets. The safety envelopes are used to keep the vehicle operating safely and can be optimized to improve permissiveness of the vehicular operation.