Methods, apparatuses and computer program products for estimating absolute wheel roll radii and/or a vertical compression value of wheels of a vehicle are disclosed, wherein yaw rates of the vehicle, wheel speeds of first and second wheels, and optionally lateral acceleration of the vehicle are measured and used as a basis for the estimation.

Methods, apparatuses and computer program products for estimating absolute wheel roll radii and/or a vertical compression value of wheels of a vehicle are disclosed, wherein yaw rates of the vehicle, wheel speeds of first and second wheels, and optionally lateral acceleration of the vehicle are measured and used as a basis for the estimation.

A method, a system and a computer-readable medium for detecting a wheel tread depth include a first detector, a second detector and a processor. The first detector is configured to detect a moving distance of a vehicle moved by at least one wheel. The second detector is configured to detect a number of tunes of the wheel while the vehicle moves the moving distance. The processor is electrically connected to the first detector and the second detector. The processor is configured to compute a current diameter of the wheel according to the moving distance and the number of tunes of the wheel and determine a parameter of the tread pattern of the wheel according to the current diameter of the wheel and a reference value.

In a method of determining a radius or diameter of a train wheel, a camera mounted on a train acquires first and second images (pictures) of first and second objects spaced along a path being traveled by the train. Matches are then determined between the first and second objects appearing in the first and second acquired images and representations (pictures) of the first and second objects appearing in prerecorded images included in a track database that include corresponding first and second geographical locations. A distance L traveled by the train between the first and second geographical locations is determined and a sum C of electrical pulses generated by an encoder coupled to the train wheel during travel of the train the distance L is determined. Based on the distance L and the sum C, a diameter or radius of the wheel is determined.

The invention relates to a method for estimating a current wheel circumference of at least one wheel arranged on a vehicle, said method comprising: determining a reference speed of the vehicle at a point in time by means of a reference apparatus, detecting a wheel rotational speed of the at least one wheel at said point in time by means of a wheel rotational speed sensor, estimating a single wheel-circumference value based on the determined reference speed and the detected wheel rotational speed for said point in time by means of a calculation apparatus, storing at least the estimated single wheel-circumference value in a circular buffer for said point in time, estimating a current wheel circumference based on the single wheel-circumference values stored in the circular buffer by the calculation apparatus, outputting the estimated current wheel circumference as a wheel circumference signal.

The invention relates to a method for estimating a current wheel circumference of at least one wheel arranged on a vehicle, said method comprising: determining a reference speed of the vehicle at a point in time by means of a reference apparatus, detecting a wheel rotational speed of the at least one wheel at said point in time by means of a wheel rotational speed sensor, estimating a single wheel-circumference value based on the determined reference speed and the detected wheel rotational speed for said point in time by means of a calculation apparatus, storing at least the estimated single wheel-circumference value in a circular buffer for said point in time, estimating a current wheel circumference based on the single wheel-circumference values stored in the circular buffer by the calculation apparatus, outputting the estimated current wheel circumference as a wheel circumference signal.

Various embodiments include a reflectometer and a reflectometry system for monitoring movements of a substrate, such as a silicon wafer. In one embodiment, a reflectometry system monitors and controls conditions associated with a substrate disposed within a process chamber. The process chamber includes a substrate-holding device having an actuator mechanism to control movement of the substrate with respect to the substrate-holding device. The reflectometry system includes a light source configured to emit a beam of light directed at the substrate, collection optics configured to receive light reflected from the substrate by the beam of light directed at the substrate and output a signal related to one or more conditions associated with the substrate, and a processor configured to process the signal and direct the actuator mechanism to control the movement of the substrate with respect to the substrate-holding device based on the signal. Other devices and methods are disclosed.

Various embodiments include a reflectometer and a reflectometry system for monitoring movements of a substrate, such as a silicon wafer. In one embodiment, a reflectometry system monitors and controls conditions associated with a substrate disposed within a process chamber. The process chamber includes a substrate-holding device having an actuator mechanism to control movement of the substrate with respect to the substrate-holding device. The reflectometry system includes a light source configured to emit a beam of light directed at the substrate, collection optics configured to receive light reflected from the substrate by the beam of light directed at the substrate and output a signal related to one or more conditions associated with the substrate, and a processor configured to process the signal and direct the actuator mechanism to control the movement of the substrate with respect to the substrate-holding device based on the signal. Other devices and methods are disclosed.

A method for iteratively determining the radius of a wheel of a number of wheels can be utilized for a motor vehicle having a driving direction sensor unit for detecting straight line travel, with each wheel being assigned an incremental sensor unit for detecting increments embodying wheel rotational movements. The method may involve checking whether the motor vehicle is driving based on the incremental sensor units, checking whether the motor vehicle is driving in a straight line based on the driving direction sensor unit, checking whether each wheel is slide-free and slip-free based on the incremental sensor units, determining the distance driven by each wheel based on the sensor value of the respective incremental sensor unit and the radius to be iteratively determined of the wheel of a previous iteration, determining the distance driven by the motor vehicle based on the distance driven by each wheel, determining the radius to be iteratively determined of the wheel based on the distance traveled by the motor vehicle and the sensor value of the respective incremental sensor unit, verifying that a validation condition is met and then repeating the aforementioned steps.

A method for iteratively determining the radius of a wheel of a number of wheels can be utilized for a motor vehicle having a driving direction sensor unit for detecting straight line travel, with each wheel being assigned an incremental sensor unit for detecting increments embodying wheel rotational movements. The method may involve checking whether the motor vehicle is driving based on the incremental sensor units, checking whether the motor vehicle is driving in a straight line based on the driving direction sensor unit, checking whether each wheel is slide-free and slip-free based on the incremental sensor units, determining the distance driven by each wheel based on the sensor value of the respective incremental sensor unit and the radius to be iteratively determined of the wheel of a previous iteration, determining the distance driven by the motor vehicle based on the distance driven by each wheel, determining the radius to be iteratively determined of the wheel based on the distance traveled by the motor vehicle and the sensor value of the respective incremental sensor unit, verifying that a validation condition is met and then repeating the aforementioned steps.