An apparatus for determining a wheel condition on whether wheel locking occurs in each wheel of a vehicle having a main brake apparatus and an auxiliary brake apparatus. The apparatus includes: a WSS (Wheel Speed Sensor) configured to primarily detect whether wheel locking occurs; a TPMS (Tire Pressure Monitoring System) configured to secondarily detect whether wheel locking occurs; and a control unit configured to determine, when the WSS fails, a wheel condition indicative of whether wheel locking occurs in each wheel, by using information detected through the TPMS.

A braking control method according to friction of road surface includes computing a real-time wheel speed according to a signal received from a wheel speed sensor; storing the real-time wheel speed as a wheel initial velocity when a braking event occurs; determining a relative-peak value according to the real-time wheel speed; estimating a vehicle deceleration according to the relative-peak value and the wheel initial velocity; computing an adjustment parameter according to the vehicle deceleration and a tire slip threshold, wherein the adjustment parameter reflects friction coefficient of road surface; and adjusting time length of an enhancement stage in an enhance-pressure control period of a stepped pressure-increasing phase according to the adjustment parameter; or adjusting time length of a reduction stage in a reduce-pressure control period of a stepped pressure-decreasing phase according to the adjustment parameter.

A tire (100) rolls on a surface (105). A method (600) for providing maximum traction coefficient between the tire (100) and the surface (105) include steps for detecting a momentary slip of the tire (100) on the surface (105); detecting a momentary traction coefficient; forming a tuple (410, 510) from the slip and the current traction coefficient; choosing a characteristic curve (205, 305) from a number of predetermined characteristic curves (205, 305) on the basis of the tuple (410, 510), whereby each characteristic curve (205, 305) describes a traction behavior of the tire (100) or a corresponding characteristic pitch; determining the maximum traction coefficient on the basis of the selected characteristic curves (205, 305); and thus providing the maximum traction coefficient.

A road surface condition estimation apparatus which accurately estimates a road surface condition even under changes of external environment such as weather, etc., and a road surface condition estimation method using the same is described. The road surface condition estimation apparatus includes: a sensor module which is mounted on a tire; a receiver module which receives sensing information measured by the sensor module; a processing module which extracts a parameter for estimating a road surface condition by analyzing the sensing information received by the receiver module; and an estimation module which estimates the road surface condition by using the parameter extracted by the processing module. The sensing information includes an acceleration of the tire.

The disclosure relates to a method for monitoring behavior of a tire of a vehicle in a rolling condition of the tire, comprising the steps of: acquiring a signal representative of an acceleration of a specified point of the tire, deriving from the signal a curve which represents a profile of the acceleration of the point during a revolution of the tire, determining a leading portion and a trailing portion of the curve, corresponding to an entry of the point into a footprint region of the tire and corresponding to an exit of the point from the footprint region of the tire, respectively, determining a first measure of a volatility of the signal in the leading portion and a second measure of a volatility of the signal in the trailing portion, and determining an indication of the behavior of the tire based on the first measure and the second measure.

Techniques are described for determining weight distribution of a vehicle. A method of performing autonomous driving operation includes receiving two sets of values from two sets of sensors, where a first set of sensors measure weights or pressures applied on axles of a vehicle, and where a second set of sensors measure pressures in tires of the vehicle. The method performs an error detection and removal operation to remove or filter out any erroneous values from the two sets of values to obtain two sets of filtered values. The method determines one or more values that describe a weight or pressure applied on the axle to obtain the weight distribution of the vehicle based on the first set of filtered values or the second set of filtered values. Based on the obtained weight distribution of the vehicle, the method can determine a driving operation of the vehicle.

A detection system for extracting information from a sensor module in a rolling wheel comprises: a sensor module which comprises a sensor adapted for sensing a physical property of the tire when mounted in a tire of the wheel or on an inner surface of a tire of the wheel; an acquisition module adapted for sampling a signal from the sensor module, thus obtaining a sequence of data samples; a correlation module adapted for cross-correlating a signed reference sequence with the sequence of data samples thus obtaining a correlation sequence; an extraction module adapted for identifying at least one perturbation in the correlation sequence, wherein the perturbation is induced when a part of the tire where the sensor is mounted hits the ground thereby forming the tire patch.

The invention relates to an acceleration sensor, especially a duplex acceleration sensor, an arrangement and a method for detecting a loss of road grip of a vehicle wheel (3). The acceleration sensor comprises a tube (5) having a longitudinal axis forming a circular arc segment, and two closed ends. A mass (15; 315) is arranged inside the tube (5) such that is able to move inside the tube (5) in the longitudinal direction thereof. A magnet arrangement (17; 203; 205; 317) is designed to counteract, by way of a magnetic force exerted on the mass (15; 315), a movement of said mass (15; 315) from an idle position (25), and a read-out unit (608) is designed to detect a movement of said mass (15) from the idle position (25).

A tire side device is provided with a vibration detection unit that outputs a detection signal corresponding to the magnitude of tire vibration, a control unit that performs to generate road surface data indicating a road surface condition that appears in the waveform of the detection signal, and a first data communication unit that transmits the road surface data. Furthermore, a vehicle body side system is provided with a second data communication unit that receives the road surface data transmitted from the first data communication unit, and a road surface determination unit that determines the condition of the road surface that the vehicle is traveling on the basis of the road surface data. In addition, sensing is performed by the control unit under different sensing conditions at the tire side device of at least one tire among a plurality of tires and the tire side device of at least one other tire among the plurality of tires, and road surface data generated on the basis of the different sensing conditions is transmitted from the first data communication unit.

A tire system includes a tire-side device and a vehicle-body-side system. The tire-side device may be attached to a tire included in a vehicle. The vehicle-body-side system may be attached to a body of the vehicle. The tire-side device may output a detection signal corresponding to each of a plurality of types of detection targets. The tire-side device may perform processing of the detection signal and generate the data related to the detection target. The tire-side device may perform bidirectional communication with the vehicle-body-side system and transmit the data to the vehicle-body-side system. The vehicle-body-side system may perform bidirectional communication with the tire-side device and receive the data. The vehicle-body-side system may acquire the detection result for the detection target based on the data.