A wheel speed measuring device for an aircraft braking system uses dual technology packaged in a single transducer that incorporates the robust and reliable variable reluctance technology along with a secondary package for measuring position and velocity bi-directionally for low speed and taxi operations. The transducer of the present invention is preferably incorporated into the envelope of the axle to allow both retrofit on existing aircraft and to maintain existing axle design and configuration.

A tire mount sensor detects a road surface condition such as a type of a road surface and a road surface , and transmits road surface data indicating a detection result to a communication center. The communication center collects road surface data more precisely, and the vehicle receives the more precise road surface data from the communication center. Based on received more precise road surface data, the risk of the vehicle is determined. Thus, the road surface condition is detected using the tire mount sensor, so that the road surface condition is detected without braking. Accordingly, it is possible to detect the road surface condition with high frequency, so that the road surface condition is detected in wider area, and it is possible to perform the control more appropriately for avoiding the risk based on the road surface condition during a travel.

When detecting a maladjusted brake component on a commercial vehicle, wheel end temperature is determined as a function of resistance measured by a wheel speed sensor at a wheel end. The measured temperature is compared to low and high temperature thresholds defined by a thermal model, as well as to one or more other wheel speed sensor temperatures. If the measured temperature is below the low temperature threshold and substantially different than the one or more other wheel speed sensors, the brake is determined to be under-adjusted and brake force at the under-adjusted brake is increased. If the measured temperature is above the high temperature threshold and substantially different than the one or more other wheel speed sensors, then the brake is determined to be over-adjusted, and brake force is reduced or modulated at the over-adjusted brake to prevent overheating.

In order to detect a road surface condition, a road surface condition estimation device extracts a detection signal of a portion that detects vibration in a tire tangential direction in a vibration detection and power generation unit which is in a ground contact section, for example, a vibration power generation element. In this case, it is identified that the vibration detection and power generation unit is in the ground contact section, based on whether a centrifugal force acting on the vibration detection and power generation unit is generated, or not, and it is identified that a time when no centrifugal force is generated is in the ground contact section. As a result, even if a pulse level of an output voltage of the vibration detection generation unit changes according to a traveling speed of the vehicle, the ground contact section can be accurately identified.

The dynamic footprint of a tire is received and the dynamic footprint is determined by and received from a tire pressure monitoring (TPM) sensor. A weight or load of the secondary vehicle attached to the primary vehicle is calculated based at least in part on the footprint. Instructions to alter the operation of the braking system of the secondary vehicle based on the calculated weight or load are transmitted to the secondary vehicle.

A multi-layer light alert display apparatus and control method thereof are provided. The apparatus includes: an illumination device configured to illuminate a graphic generating layer, a plurality of graphic generating layers, each graphic generating layer of the plurality of graphic generating layers being configured to generate a graphic, and a controller configured to control the illumination device to allow light to pass through at least one graphic generating layer of the plurality of graphic generating layers so that the light causes a graphic corresponding to the at least one graphic generating layer to be displayed on a surface.

Assembly comprising a vehicle (13, 13a-c) having a plurality of wheels (2), each of the wheels (2) arranged to support a weight of the vehicle (13) against an underlying surface (5); a sensor (10) operable to measure a force between one of the wheels (2) and a body of the vehicle (13, 13a-c); and a processor (15) configured to receive measurement data from the sensor (10). There is also provided a method for measuring conditions of a drive surface (5) and a method of operating vehicles (13, 13a-d) on a road (5).

Systems and methods are disclosed for estimating slipperiness of a road surface. This estimate may be obtained using an image sensor mounted on a vehicle. The estimated road slipperiness may be utilized when calculating a risk index for the road, or for an area including the road. If a predetermined threshold for slipperiness is exceeded, corrective actions may be taken. For instance, warnings may be generated to human drivers that are in control of driving vehicle, and autonomous vehicles may automatically adjust vehicle speed based upon road slipperiness detected.

Sensor systems using piezoresistive materials are described that may be integrated with vehicle tires for use in a variety applications such as, for example, tire pressure monitoring, tread wear monitoring, anti-lock braking system control, suspension adjustment and/or control, wheel-drive system control, or road surface determination.

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).