Patent attributes
This invention is intended to enable performing a vehicle straight-line performance adjustment operation surely in a short time without the need of operator's skill. An actually moving state of a vehicle completed with an alignment adjustment is reproduced after the vehicle is mounted on rollers of a bench tester, and the side force of each of wheels at this time is measured, it is determined whether or not the measured side force is within a preset reference range, it is determined whether or not the side force of the wheel, which has been determined to be out of the reference range, is within the reference range when a toe angle of the wheel is corrected within a preset toe angle correction allowable range, the toe angle is corrected within the correction allowable range when it is determined that the side force falls within the reference range, and the side force is corrected to fall within the reference range, the side force of the each wheel after the toe angle is corrected is obtained, a drift amount of the vehicle is calculated from the obtained side force of the each wheel, and it is determined whether or not the vehicle has a good straight-line performance based on the calculated drift amount.
