Method for determining error sources in a wheel balancer

Claim 1

A method of detecting errors affecting measurement of wheel unbalance compensation weights taken in a wheel balancer having a rotatable wheel mounting shaft supported in a framework, a wheel mount on the shaft formed to accept a wheel for attachment thereto, a motor coupled to drive the shaft rotationally, left and right force transducers mounted between the framework and the shaft so that they detect mass unbalance in the shaft and in structure secured to the wheel mount during shaft rotation, a display, a processor operating to monitor output from the force transducers, to control the motor and to provide signals coupled to the display indicative of unbalance compensation magnitude and location, and memory associated with the processor operating to store unloaded shaft unbalance and force transducer calibration data, comprising the steps of accelerating the shaft to assume a continuous speed within a predetermined speed range, measuring the force transducer outputs, calculating uncorrected unbalance integrals from the force transducer outputs, correcting the unbalance integrals with the unloaded shaft unbalance data, calculating the forces at the left and right transducers from the corrected unbalance integrals and the stored calibration data for a predetermined number of shaft revolutions, calculating the unbalance compensation weights using a set of arbitrary wheel parameters and the corrected unbalance integrals obtained over the predetermined number of shaft revolutions, and repeating all of the foregoing steps after each completion of the predetermined number of shaft revolutions, whereby a series of compensation weight values is obtained and the stability of the system may be observed.

Claim 2

A method of detecting errors affecting measurement of wheel unbalance compensation weights taken in a wheel balancer having a rotatable wheel mounting shaft supported in a framework, a wheel mount on the shaft formed to accept a wheel for attachment thereto, a motor coupled to drive the shaft rotationally, left and right force transducers mounted between the framework and the shaft so that they detect mass unbalance in the shaft and in structure secured to the wheel mount during shaft rotation, a display, a processor operating to monitor output from the force transducers, to control the motor and to provide signals coupled to the display indicative of unbalance compensation magnitude and location, and memory associated with the processor operating to store unloaded shaft unbalance and force transducer calibration data, comprising the steps of accelerating the shaft to assume a continuous speed within a predetermined speed range, measuring the force transducer outputs, calculating uncorrected unbalance integrals from the force transducer outputs, correcting the unbalance integrals with the unloaded shaft unbalance data, calculating the forces at the left and right transducers from the corrected unbalance integrals and the stored calibration data for a predetermined number of shaft revolutions, calculating the unbalance compensation weights using a set of arbitrary wheel parameters and the corrected unbalance integrals obtained over the predetermined number of shaft revolutions, and repeating all of the foregoing steps after each completion of the predetermined number of shaft revolutions, whereby a series of compensation weight values is obtained and the stability of the system may be observed.

Claim 8

A method of detecting error in measurement of wheel unbalance compensation weights performed by a wheel balancer having a rotatable shaft with a wheel mount thereon, a framework supporting the shaft for rotation therein, a motor coupled to drive the shaft rotationally, force transducers mounted between the framework and the shaft providing output during shaft rotation indicative of mass unbalance in the shaft and in structure secured to the wheel mount, a display, a processor operating to monitor output from the force transducers, to control the motor and to provide outputs coupled to the display which are indicative of unbalance compensation weight magnitude and location, and memory associated with the processor operating to store unloaded shaft unbalance and force transducer calibration data, comprising the steps of continuously driving the shaft at a speed within a predetermined speed range, measuring the force transducer outputs, filtering the force transducer outputs to retain the fundamental frequency and to attenuate harmonic frequencies, the step of filtering occurring over a predetermined number of shaft revolutions, converting the filtered outputs to display-compatible signals, and displaying the converted outputs for a series of periods defined by the predetermined number of shaft revolutions.

Claim 9

A method of detecting error in measurement of wheel unbalance compensation weights performed by a wheel balancer having a rotatable shaft with a wheel mount thereon, a framework supporting the shaft for rotation therein, a motor coupled to drive the shaft rotationally, force transducers mounted between the framework and the shaft providing output during shaft rotation indicative of mass unbalance in the shaft and in structure secured to the wheel mount, a display, a processor operating to monitor output from the force transducers, to control the motor and to provide outputs coupled to the display which are indicative of unbalance compensation weight magnitude and location, and memory associated with the processor operating to store unloaded shaft unbalance and force transducer calibration data, comprising the steps of continuously driving the shaft at a speed within a predetermined speed range, measuring the force transducer outputs, filtering the force transducer outputs to retain the fundamental frequency and to attenuate harmonic frequencies, the step of filtering occurring over a predetermined number of shaft revolutions, converting the filtered outputs to display-compatible signals, and displaying the converted outputs for a series of periods defined by the predetermined number of shaft revolutions.

Claim 17

A method of detecting errors in measurement of mass unbalance magnitude and location on a wheel balancing machine having a rotatable shaft with a wheel mount attached thereto, a framework supporting the shaft, a motor coupled to rotationally drive the shaft, force transducers positioned between the framework and the shaft providing outputs indicative of mass unbalance in the shaft and in structure attached to the shaft mount during shaft rotation, a display, a processor operating to monitor output from the force transducers, to control the motor and to provide signals coupled to the display indicative of the mass unbalance, and memory associated with the processor operating to store unloaded shaft unbalance and force transducer calibration data, comprising the steps of inhibiting rotation of the shaft, transmitting the unloaded shaft unbalance data to the processor, calculating the force transducer forces corresponding to the unloaded shaft unbalance data and a predetermined shaft rotation speed, calculating the counterweight magnitude and location necessary to counterbalance the measured mass unbalance, and displaying the counterweight magnitude and location, whereby counterweight magnitude and location displayed is shaft unbalance.

Claim 18

A method of detecting errors in measurement of mass unbalance magnitude and location on a wheel balancing machine having a rotatable shaft with a wheel mount attached thereto, a framework supporting the shaft, a motor coupled to rotationally drive the shaft, force transducers positioned between the framework and the shaft providing outputs indicative of mass unbalance in the shaft and in structure attached to the shaft mount during shaft rotation, a display, a processor operating to monitor output from the force transducers, to control the motor and to provide signals coupled to the display indicative of the mass unbalance, and memory associated with the processor operating to store unloaded shaft unbalance and force transducer calibration data, comprising the steps of inhibiting rotation of the shaft, transmitting the unloaded shaft unbalance data to the processor, calculating the force transducer forces corresponding to the unloaded shaft unbalance data and a predetermined shaft rotation speed, calculating the counterweight magnitude and location necessary to counterbalance the measured mass unbalance, and displaying the counterweight magnitude and location, whereby counterweight magnitude and location displayed is shaft unbalance.

Claim 19

A method of detecting errors in measurement of mass unbalance magnitude and location on a wheel balancing machine having a rotatable shaft with a wheel mount attached thereto, a framework supporting the shaft, a motor coupled to rotationally drive the shaft, force transducers positioned between the framework and the shaft providing outputs indicative of mass unbalance in the shaft and in structure attached to the shaft mount during shaft rotation, a display, a processor operating to monitor output from the force transducers, to control the motor and to provide signals coupled to the display indicative of the mass unbalance, and memory associated with the processor operating to store unloaded shaft unbalance and force transducer calibration data, comprising the steps of driving the shaft rotationally to a predetermined shaft rotation speed, maintaining substantially the same shaft speed, transmitting the unloaded shaft unbalance data to the processor, measuring the force transducer outputs, filtering the force transducer outputs to retain the fundamental frequency and to attenuate harmonic frequencies, the filtered transducer output measuring step occurring over a predetermined number of shaft revolutions, converting the filtered outputs to display compatible signals, and serially displaying the converted outputs corresponding to data obtained during subsequent periods defined by the predetermined number of shaft revolutions.

Claim 20

A method of detecting errors in measurement of mass unbalance magnitude and location on a wheel balancing machine having a rotatable shaft with a wheel mount attached thereto, a framework supporting the shaft, a motor coupled to rotationally drive the shaft, force transducers positioned between the framework and the shaft providing outputs indicative of mass unbalance in the shaft and in structure attached to the shaft mount during shaft rotation, a display, a processor operating to monitor output from the force transducers, to control the motor and to provide signals coupled to the display indicative of the mass unbalance, and memory associated with the processor operating to store unloaded shaft unbalance and force transducer calibration data, comprising the steps of driving the shaft rotationally to a predetermined shaft rotation speed, maintaining substantially the same shaft speed, transmitting the unloaded shaft unbalance data to the processor, measuring the force transducer outputs, filtering the force transducer outputs to retain the fundamental frequency and to attenuate harmonic frequencies, the filtered transducer output measuring step occurring over a predetermined number of shaft revolutions, converting the filtered outputs to display compatible signals, and serially displaying the converted outputs corresponding to data obtained during subsequent periods defined by the predetermined number of shaft revolutions.

Claim 28

A method of detecting errors affecting measurement of mass unbalance magnitude and location using a wheel balancing machine having a rotatable shaft with a wheel mount attached thereto, a framework supporting the shaft, a motor coupled to rotationally drive the shaft, force transducers positioned between the framework and the shaft providing outputs indicative of mass unbalance in the shaft and in structure attached to the shaft mount during shaft rotation, a display, and a processor operating to monitor output from the force transducers, to control the motor and to provide signals coupled to the display indicatove of the mass unbalance, comprising the steps of continuously driving the shaft rotationally to assume a speed within a predetermined speed range, sensing the force transducer outputs, filtering the force transducer outputs to retain the fundamental output frequency and to attenuate harmonic frequencies, calculating transducer forces from the filtered outputs for a predetermined number of shaft revolutions, calculating the balance weight and position necessary to counterbalance the mass unbalance utilizing the calculated transducer forces and arbitrary wheel parameters, and repeating the foregoing sequence of steps after each period defined by the predetermined number of shaft revolutions, so that a series of compensation weight values is obtained indicative of the stability of the system.

Claim 29

A method of detecting errors affecting measurement of mass unbalance magnitude and location using a wheel balancing machine having a rotatable shaft with a wheel mount attached thereto, a framework supporting the shaft, a motor coupled to rotationally drive the shaft, force transducers positioned between the framework and the shaft providing outputs indicative of mass unbalance in the shaft and in structure attached to the shaft mount during shaft rotation, a display, and a processor operating to monitor output from the force transducers, to control the motor and to provide signals coupled to the display indicatove of the mass unbalance, comprising the steps of continuously driving the shaft rotationally to assume a speed within a predetermined speed range, sensing the force transducer outputs, filtering the force transducer outputs to retain the fundamental output frequency and to attenuate harmonic frequencies, calculating transducer forces from the filtered outputs for a predetermined number of shaft revolutions, calculating the balance weight and position necessary to counterbalance the mass unbalance utilizing the calculated transducer forces and arbitrary wheel parameters, and repeating the foregoing sequence of steps after each period defined by the predetermined number of shaft revolutions, so that a series of compensation weight values is obtained indicative of the stability of the system.

Claim 33

A method of detecting errors affecting measurement of mass unbalance magnitude and location using a wheel balancing machine having a rotatable shaft with a wheel mount attached thereto, a framework supporting the shaft, a motor coupled to rotationally drive the shaft, force transducers positioned between the framework and the shaft providing outputs indicative of mass unbalance in the shaft and in structure attached to the shaft mount during shaft rotation, a display, and a processor operating to monitor output from the force transducers, to control the motor and to provide signals coupled to the display indicative of the mass unbalance, comprising the steps of continuously driving the shaft rotationally to assume a speed within a predetermined speed range, sensing the force transducer outputs, converting the force transducer outputs to display compatible signals, displaying the converted outputs for a series of periods each defined by a predetermined number of shaft revolutions.

Claim 34

A method of detecting errors affecting measurement of mass unbalance magnitude and location using a wheel balancing machine having a rotatable shaft with a wheel mount attached thereto, a framework supporting the shaft, a motor coupled to rotationally drive the shaft, force transducers positioned between the framework and the shaft providing outputs indicative of mass unbalance in the shaft and in structure attached to the shaft mount during shaft rotation, a display, and a processor operating to monitor output from the force transducers, to control the motor and to provide signals coupled to the display indicative of the mass unbalance, comprising the steps of continuously driving the shaft rotationally to assume a speed within a predetermined speed range, sensing the force transducer outputs, converting the force transducer outputs to display compatible signals, displaying the converted outputs for a series of periods each defined by a predetermined number of shaft revolutions.