A method of calibrating positions of wheels in an AGV, the method including positioning a second wheel tangentially on an imaginary second circle centered with respect to a center position in which a first wheel is fixed; driving the second wheel a second distance along the second circle such that the AGV rotates about the center position; determining the second distance based on data from a second wheel sensor device of the second wheel; determining an angle of rotation about the center position based on data from a first steering sensor device of the first wheel during the rotation of the AGV; and determining relative positions between the first wheel and the second wheel based on the second distance and the angle of rotation. An AGV is also provided.

A notification apparatus comprises a receiving part that receives a designation of a reference position; a specifying part that specifies a current wheel nut at the same position as a reference wheel nut, which is one of a plurality of wheel nuts included in a reference image that is a captured image acquired by the acquiring part in the past, from the captured image acquired by the acquiring part, with respect to the reference position; and a detecting part that detects looseness of the current wheel nut by detecting that the current wheel nut specified by the specifying part has rotated with respect to the reference wheel nut included in the reference image.

A state determination device for a hub unit bearing includes: a holding unit that holds reference information of magnetic characteristics at a predetermined position in the vicinity of a flange portion included in the hub unit bearing; an acquisition unit that acquires measurement information of the magnetic characteristics at the predetermined position of the hub unit bearing; a derivation unit that derives a change amount between the reference information held by the holding unit and the measurement information acquired by the acquisition unit; and a determination unit that determines a state of the hub unit bearing based on the change amount derived by the derivation unit. The predetermined position is a position at which the magnetic characteristics vary with a stress change with respect to the flange portion.

A sensor system includes one or more sensors that sense vibrations of a vehicle and one or more processors that can determine a speed of the vehicle and determine whether the vibrations occurring at one or more frequencies of interest (that are based on the speed of the vehicle) indicate damage to a propulsion system of the vehicle. The one or more processors optionally may determine a hunting frequency of a wheel and axle set and/or a lateral acceleration of the wheel and axle set from the vibrations. The one or more processors can determine a conicity of a wheel in the wheel and axle set based on the hunting frequency and/or the lateral acceleration that is determined.

A sensor system includes one or more sensors that sense vibrations of a vehicle and one or more processors that can determine a speed of the vehicle and determine whether the vibrations occurring at one or more frequencies of interest (that are based on the speed of the vehicle) indicate damage to a propulsion system of the vehicle. The one or more processors optionally may determine a hunting frequency of a wheel and axle set and/or a lateral acceleration of the wheel and axle set from the vibrations. The one or more processors can determine a conicity of a wheel in the wheel and axle set based on the hunting frequency and/or the lateral acceleration that is determined.

A monitoring device includes a housing adhered to a drop well of a wheel inside of a vehicle tire. The housing rotates with the wheel. An electrical circuit disposed within the housing. The electrical circuit including a load sensing device disposed within the housing. The load sensing device sensing forces exerted on the wheel. A transceiver coupled to the electrical circuit. The transceiver communicates load data sensed by the load sensing device to components exterior of the wheel.

A monitoring device includes a housing adhered to a drop well of a wheel inside of a vehicle tire. The housing rotates with the wheel. An electrical circuit disposed within the housing. The electrical circuit including a load sensing device disposed within the housing. The load sensing device sensing forces exerted on the wheel. A transceiver coupled to the electrical circuit. The transceiver communicates load data sensed by the load sensing device to components exterior of the wheel.

A method of matching a wheel and a tire includes steps of: measuring inner runout and outer runout of a wheel; extracting and setting a primary component of a measurement waveform of the inner runout as an inner runout waveform and extracting and setting a primary component of a measurement waveform of the outer runout as an outer runout waveform; comparing an inner minimum value that is a minimum value of the inner runout waveform and an outer minimum value that is the minimum value of the outer runout waveform with a predetermined runout reference value; and determining an assembly reference position of the wheel based on the inner minimum value or the outer minimum value or based on a resultant waveform of the inner runout waveform and the outer runout waveform, depending on a result of the comparing step.

An estimation system includes: a first sensor that can be disposed between a wheel and a tire mounted on the wheel and outputs a first sensor signal in accordance with a pressing force applied by the wheel and the tire; and a processor that estimates a state of a rotating body including the wheel and the tire based on the first sensor signal. The processor generates a first section signal by dividing the first sensor signal by a specific section and estimates the state of the rotating body based on the first section signal.

An estimation system includes: a first sensor that can be disposed between a wheel and a tire mounted on the wheel and outputs a first sensor signal in accordance with a pressing force applied by the wheel and the tire; and a processor that estimates a state of a rotating body including the wheel and the tire based on the first sensor signal. The processor generates a first section signal by dividing the first sensor signal by a specific section and estimates the state of the rotating body based on the first section signal.