Abstract: Method and apparatus for testing tires to measure the rolling resistance generated while a tire rolls under a radial load, the method including the steps of mounting two tires on spindles having substantially parallel axes; wherein the two tires are substantially equivalent and have substantially equal inflation pressures; loading a first one of the tires against a second one of the tires, tread-to-tread, at a predetermined tire-to-tire test load, then measuring a distance between axes of the two tire spindles; rotating one of the tires such that it rotates the other tire; measuring the total torque required to rotate the two tires at a predetermined rotation rate; and calculating the average rolling resistance of the two tires by dividing the value of total torque by the distance between the axes of the two tire spindles. Alternatively measure force at each spindle, equating each force to that tire's rolling resistance.

Abstract: Method and apparatus for testing tires to measure the rolling resistance generated while a tire rolls under a radial load, the method including the steps of mounting two tires on spindles having substantially parallel axes; wherein the two tires are substantially equivalent and have substantially equal inflation pressures; loading a first one of the tires against a second one of the tires, tread-to-tread, at a predetermined tire-to-tire test load, then measuring a distance between axes of the two tire spindles; rotating one of the tires such that it rotates the other tire; measuring the total torque required to rotate the two tires at a predetermined rotation rate; and calculating the average rolling resistance of the two tires by dividing the value of total torque by the distance between the axes of the two tire spindles. Alternatively measure force at each spindle, equating each force to that tire's rolling resistance.

Abstract: Method and system for determining immanence of catastrophic failure for a selected tire among a plurality of tires that are concurrently in operation, the method comprising the steps of: selecting a tire from the plurality of tires; monitoring vibration amplitude versus time signals for the selected tire; using signal averaging to minimize signal noise in the selected tire's vibration signals; at selected intervals, fast Fourier transforming the averaged vibration signals to create a harmonic spectrum for the selected tire; cleaning the selected tire's harmonic spectrum by applying coherence function and averaging calculations to it for minimizing contributions to the selected tire's harmonic spectrum from all other vibration sources including the remaining one(s) of the plurality of tires; comparing the most recent cleaned spectrum with stored values of previous cleaned spectra of the selected tire to track changes in higher order harmonic magnitudes; and determining whether catastrophic failure of the selec

Abstract: The invention provides a system and method for measuring tire forces wherein the force contributions of the test machine may be separated from the force contributions of the tire. The invention achieves the separation of the forces by equipping the test station with a plurality of accelerometers that allow the forces and the moments of the components of the measurement station to be calculated and accounted for in the overall force measurement. In one embodiment, the test station uses a slip ring disposed between the rotating rotor to which the tire is mounted and the stationary bearing housing to allow data to be easily gathered from the accelerometers mounted on the rotor. The slip ring also allows tires to be easily mounted and dismounted.

Abstract: Dynamic force measurement methods and systems for measuring forces applied to a structure by use of accelerometers attached to masses of the structure supported by one or more load cells. A load cell signal is combined with a summation of the accelerometer readings multiplied by the corresponding attached masses to produce a measurement of a force applied to the structure. An unknown applied force f(t) is determined by summing the load cell measured force with all other forces that exist between the load cell and the unknown force. The methods and systems can be employed in any type of load or force measuring machine or device.

Abstract: An acceleration pulse modulation method for HYGE (Hydraulically Controlled, Gas Energized) crash simulation sleds uses servo-controlled accelerators on moveable parts of the crash simulator components and acceleration measurement instrumentation for comparison of measure acceleration of the sled with a desired acceleration to enable dynamic adjustment of the total accelerating force applied to the sled via servo-controlled accelerators, based upon measured acceleration error in order to eliminate acceleration error.

Abstract: An acceleration pulse modulation method for HYGE-type crash simulation sleds uses servo-controlled accelerators on moveable parts of the crash simulator components and acceleration measurement instrumentation for comparison of measure acceleration of the sled with a desired acceleration to enable dynamic adjustment of the total accelerating force applied to the sled via servo-controlled accelerators, based upon measured acceleration error in order to eliminate acceleration error.

Abstract: The invention provides a system and method for measuring tire forces wherein the force contributions of the test machine may be separated from the force contributions of the tire. The invention achieves the separation of the forces by equipping the test station with a plurality of accelerometers that allow the forces and the moments of the components of the measurement station to be calculated and accounted for in the overall force measurement. In one embodiment, the test station uses a slip ring disposed between the rotating rotor to which the tire is mounted and the stationary bearing housing to allow data to be easily gathered from the accelerometers mounted on the rotor. The slip ring also allows tires to be easily mounted and dismounted.

Abstract: Methods and systems for measurement of mechanical properties of elastomeric materials use a driving point impedance head such as a load cell instrumented hammer to apply forces to a force distribution mass positioned over a test specimen upon a rigid base. Broad frequency responses of the driving point impedance head reveal elastic and viscous moduli response frequencies from 0 Hz to 2000 Hz. Methods and systems for measuring responses of elastomeric materials under a preload are also disclosed.

Abstract: A tire testing device which is constructed to compensate for the elastic deformation that occurs in the structural components supporting a test tire when the test tire is loaded against a roadwheel. The present construction also prevents mechanical resonances in the tire load frame during high frequency testing which permits undistorted measurements of higher harmonic force variation from the tire. The test tire is mounted to a rotatable spindle within a housing for selective engagement with a roadwheel. The housing is supported and maneuvered by a plurality of vertical and horizontal members, each member including universal joints at its opposite ends. The horizontal members are arranged in a trapezoidal or nonparallel configuration such that a small acute angle is formed between the outer surface of the test tire and the outer surface of the roadwheel when the test tire is drawn against the roadwheel.

Abstract: A high speed tire uniformity testing device which is constructed to prevent mechanical resonances in the tire load frame during high frequency testing, thereby permitting undistorted measurements of higher harmonic force variation signals from the tire. A test tire is mounted to a rotatable spindle within a housing for selective engagement with a road wheel. The housing is supported and maneuvered by a plurality of vertical and horizontal members, each member including universal joints at its opposite ends to prevent bending moments from being applied to the members. Since only tension and compression forces are applied to the members, a very stiff load frame is provided for the test tire. One of the members comprises a linear actuator which is spaced substantially away from the longitudinal axis of the housing to provide additional stability to the housing during testing.

Abstract: A device (10) and embodied method for producing pneumatic tires having preselected noise characteristics includes an output spectrum generator (11) for generating those noise characteristics, a fast Fourier transformer (12) for generating the periodic function which yields the desired noise characteristics, and a processing circuit (13). Processing circuit (13) substantially proportionally adjusts the magnitude of this periodic function such that its relative amplitude at various points in time throughout one period is directly substantially proportional to the length (L.sub.1 . . . L.sub.8) of individual tread pitch elements (P.sub.1 . . . P.sub.8) at similarly spaced locations along the tire circumference, all as may be embodied in a pneumatic tire produced in accordance with the described method.