A road surface condition estimation device extracts a detection signal of a vibration power generation element during a ground contact section to detect a road surface condition. A threshold used for determination of the ground contact section is variable according to a traveling speed of a vehicle. As a result, even if a pulse level of an output voltage of the vibration power generation element changes according to the traveling speed of the vehicle, the threshold corresponding to the change can be set. The ground contact section is determined with the use of the above thresholds, thereby being capable of performing the determination with high accuracy. Therefore, the road surface condition can be detected with high accuracy based on the ground contact section determined with high accuracy.

A computer that includes a processor and memory that stores instructions executable by the processor. The instructions may include generating, at a host vehicle, a roadway friction map by: detecting a velocity change of a target vehicle; calculating friction data based on the velocity change; and storing the friction data.

A vehicle brake device provided with a hydraulic pressure generating portion, an actuator and a controlling portion which maintains a driving force of the driving portion when a control subject pressure in a control subject chamber is within a dead zone, wherein the control subject pressure varies in response to a variation of the master pressure and a pulsation is generated in the master pressure accompanying an operation of the actuator. The vehicle brake device further includes a rigidity information obtaining portion which obtains a rigidity information and a dead zone setting portion which sets the dead zone based on the rigidity information obtained by the rigidity information obtaining portion such that the higher the rigidity of the control subject chamber, or the higher the probability of rigidity increase of the control subject chamber, the wider the dead zone is set.

The disclosure relates to a method for operating an inertial sensor of a vehicle, in particular a motor vehicle, wherein measurement data of at least one measurement variable of the inertial sensor are captured during operation of the vehicle and are checked for error values in order to calibrate the inertial sensor. According to the disclosure, during operation of the vehicle, measurement data of a different measurement variable, which, however, correlates with the measurement variable of the inertial sensor, are captured by means of a reference sensor and are compared with the measurement data of the inertial sensor in order to record the error values in accordance with a deviation of the measurement data of the inertial sensor from the measurement data of the reference sensor.

When a driving support electronic control unit (DSECU) determines that a driver of a vehicle is in an abnormal state where the driver loses an ability to drive the vehicle, the DSECU starts driving control under the abnormal state to decelerate the vehicle until the vehicle stops and to sound a horn. In this case, the DSECU measures an elapsed time since the horn starts sounding with a horn timer th, and sets a sounding pattern corresponding to the elapsed time measured. This sounding pattern is set in such a manner that a ratio of a sounding time of the horn per unit time decreases as the elapsed time since the horn starts sounding become longer. Thereby, it becomes possible to properly notify that the driver is in the abnormal state using the horn.

When a driving support electronic control unit (DSECU) determines that a driver of a vehicle is in an abnormal state where the driver loses an ability to drive the vehicle, the DSECU starts driving control under the abnormal state to decelerate the vehicle until the vehicle stops and to sound a horn. In this case, the DSECU measures an elapsed time since the horn starts sounding with a horn timer th, and sets a sounding pattern corresponding to the elapsed time measured. This sounding pattern is set in such a manner that a ratio of a sounding time of the horn per unit time decreases as the elapsed time since the horn starts sounding become longer. Thereby, it becomes possible to properly notify that the driver is in the abnormal state using the horn.

Methods, computer program products and apparatuses for estimating the uncertainty of a friction potential value of a wheel of a vehicle are disclosed. The method for estimating the uncertainty of a friction potential value of a wheel of a vehicle comprises obtaining a range of tire models (72). The method further comprises receiving a sensor signal (74) indicative of at least one actual tire-related value. Finally, a friction uncertainty value is calculated (76) based on the received sensor signal and the range of tire models. The friction uncertainty value is indicative of the uncertainty of the friction potential.

Methods, computer program products and apparatuses for estimating the uncertainty of a friction potential value of a wheel of a vehicle are disclosed. The method for estimating the uncertainty of a friction potential value of a wheel of a vehicle comprises obtaining a range of tire models (72). The method further comprises receiving a sensor signal (74) indicative of at least one actual tire-related value. Finally, a friction uncertainty value is calculated (76) based on the received sensor signal and the range of tire models. The friction uncertainty value is indicative of the uncertainty of the friction potential.

A fuzzy-based control system in a motor vehicle for controlling a speed comprises a brake pressure measurement unit, a signal processing unit and a control unit. The brake pressure measurement unit is adapted as a finite state machine to measure a current brake pressure of a brake of a wheel of the motor vehicle dependent on a trigger. The signal processing unit is adapted to estimate a current adhesion value between a tyre associated with the wheel and the current ground, based on the current brake pressure of the brake and further measurement values. The estimating comprises an inference based on fuzzy rules and a fuzzification, a subsequently a defuzzification of the inference. The control unit is adapted to control a speed of the motor vehicle or the brake pressure of the brake, based on the estimated current adhesion value .

A fuzzy-based control system in a motor vehicle for controlling a speed comprises a brake pressure measurement unit, a signal processing unit and a control unit. The brake pressure measurement unit is adapted as a finite state machine to measure a current brake pressure of a brake of a wheel of the motor vehicle dependent on a trigger. The signal processing unit is adapted to estimate a current adhesion value between a tyre associated with the wheel and the current ground, based on the current brake pressure of the brake and further measurement values. The estimating comprises an inference based on fuzzy rules and a fuzzification, a subsequently a defuzzification of the inference. The control unit is adapted to control a speed of the motor vehicle or the brake pressure of the brake, based on the estimated current adhesion value .