摘要:
A wheel balancer has a shaft for receiving a wheel/tire assembly, a rotation sensor assembly for measuring rotation of the shaft about its longitudinal axis, a motor operatively connected to the shaft for rotating said shaft about its longitudinal axis, thereby to rotate the wheel/tire assembly, a vibration sensor assembly for measuring vibration of the wheel/tire assembly as the wheel/tire assembly is rotated, and a load roller for applying a generally radial force to the wheel/tire assembly during rotation of said wheel/tire assembly. Movement of the load roller is measured to determine loaded radial runout of the wheel/tire assembly while the force is applied thereto and a a tire stiffness value for the wheel/tire assembly is provided. A control circuit is responsive to the measured vibration of the wheel/tire assembly to determine wheel imbalance, and responsive to the determined imbalance, the measured loaded radial runout of the wheel/tire assembly, and the tire stiffness to determine the locations and magnitudes of correction weights to add to the wheel/tire assembly to reduce the vibration of the wheel/tire assembly when mounted on a traveling vehicle.
摘要:
A wheel balancer has an improved drive circuit and improved safety features. The drive circuit includes an H-bridge configuration, preferably utilizing MOSFET or IGBT transistors. The safety features include an electrical brake which operates upon removal of power to safely and reliably stop the rotation of the wheel/tire assembly being balanced. A hardware safety interlock is provided to limit rpm and/or travel of the wheel/tire assembly based upon preset criteria. A novel display system is included for displaying axial, radial, and/or loaded runout of the wheel/tire assembly.
摘要:
Apparatus and method for determining the alignment of a wheel of a vehicle includes mounting a known optical target to a wheel on the vehicle, the known optical target having a plurality of optical elements, each optical element having at least one straight edge disposed on a background, obtaining at least one video image of the optical target, estimating from the video image of the optical target the characteristics in said video image of a plurality of lines corresponding to projections onto the video image of the straight edges of the optical elements, and determining from the estimates of the characteristics the alignment of the wheel. A similar target for determining the position of a runway on which the vehicle is positioned is also disclosed.
摘要:
A vehicle wheel alignment apparatus includes wheel alignment sensors for obtaining wheel alignment data, including camber, and devices for measuring wheel offset distances. A controller compensates the measured wheel offset distances for the camber of the corresponding wheels. Ride height sensors are included for measuring the ride height of the vehicle at the wheels, and the controller also uses the ride height to compensate the wheel offset distances. Ride height is similarly compensated for camber by the controller. The body angle of the vehicle is obtained from the wheel offset measurements and the wheelbase of the vehicle. The body angle is used to compute dog track angles and correct those angles by applying the body angle to the individual toe angles of the reference axle. Axle offsets are computed and used in front axle cradle adjustment if applicable. The body angle is also used to eliminate the effect of wheel offsets from setback angle calculations. The corrected setback angle is converted into a distance when track width is measured.
摘要:
The brakes of a two-axle vehicle are tested by weighing the vehicle and measuring the braking forces for both axles to determine the actual ratio of front axle braking force to total braking force. The deceleration applied to the vehicle is determined from the weight of the vehicle and the applied braking forces. A nominal preferred value of the ratio of front axle braking force to total braking force is calculated from the determined deceleration and the measured weight of the vehicle. The nominal preferred value varies from test to test with both the actual deceleration and the vehicle weight. For each test, upper and lower limits for the acceptability of the actual ratio of front axle braking force to total braking force are set based upon the computed nominal preferred value. These limits move from test to test with the computed nominal preferred value. The nominal preferred value, the movable limits, and the actual ratio are displayed to the user on a CRT screen. The actual ratio is displayed in the form of a bar on the screen, with the limits and nominal preferred value displayed as non-numeric indicia along the longitudinal axis of the bar.
摘要:
The brakes of a two-axle vehicle are tested by weighing the vehicle and measuring the braking forces for both axles to determine the actual ratio of front axle braking force to total braking force. The deceleration applied to the vehicle is determined from the weight of the vehicle and the applied braking forces. A nominal preferred value of the ratio of front axle braking force to total braking force is calculated from the determined deceleration and the measured weight of the vehicle. The nominal preferred value varies from test to test with both the actual deceleration and the vehicle weight. For each test, upper and lower limits for the acceptability of the actual ratio of front axle braking force to total braking force are set based upon the computed nominal preferred value. These limits move from test to test with the computed nominal preferred value. The nominal preferred value, the movable limits, and the actual ratio are displayed to the user on a CRT screen. The actual ratio is displayed in the form of a bar on the screen, with the limits and nominal preferred value displayed as non-numeric indicia along the longitudinal axis of the bar.
摘要:
A computer-based vehicle service system, such as a wheel alignment system, is configured with a tire pressure monitoring system interface to acquire measurements of the air pressure directly from tire pressure monitoring system sensor installed in the tires of a vehicle undergoing a service procedure. The vehicle service system is further configured to utilize the acquired air pressure measurements to complete at least one vehicle diagnostic procedure.
摘要:
An optical target for temporary application in non-determined placement on a surface of an object such as a vehicle wheel assembly within the field of view of an imaging sensor of a machine vision vehicle service system. The optical target consists of a flexible body which is relatively thin and generally flat, capable of conforming to the contours of a surface onto which it is secured in releasable manner by a means of adhesion. A set of visible optical elements are disposed on a front face of the target body for observation and imaging by the imaging sensors.
摘要:
A wheel balancer is provided that includes a shaft adapted for receiving a wheel/tire assembly and rotating a wheel/tire assembly removably mounted thereon, a motor operation connected to the shaft for rotating the shaft about its longitudinal axis, thereby rotating the wheel/tire assembly, a load roller for applying a generally radial force to the wheel/tire assembly during rotation so that loaded wheel/tire assembly measurements may be determined while the force is applied thereto and a control circuit. The control circuit is responsive the loaded wheel/tire assembly measurements and to a tire stiffness value to make a determination of a predetermined uniformity parameter.
摘要:
Matching multiple wheel rims and tires based upon runout and force variation measurements using balancing equipment. Centering errors and mounting errors are also reduced or eliminated. The method includes adjusting the rotational positions of the tires with respect to the wheel rims to compensate for wheel rim run-out and wheel/tire assembly force variations. This is accomplished in one embodiment by sequentially mounting a plurality of wheel/tire assemblies on a spindle of a balancer, measuring the rim run-out for each assembly and the force variations for each assembly, marking each tire of each assembly to identify both the individual tire and the rotational position representing the first harmonic of the tire force variation at which each tire is mounted with respect to its wheel rim, removing each tire from its wheel rim, sequentially mounting the wheel rims with tires removed on the spindle of the balancer, measuring the rim run-out for each rim, and visually indicating to a user a preferred matching between the tires and the wheel rims to minimize assembly vibration.