Wheel alignment and diagnostic apparatus utilizing ride height

A vehicle wheel alignment apparatus comprising:

• a storage device for storing vehicle wheel alignment angle specifications;
• at least one wheel alignment sensor for acquiring wheel alignment angle data for first and second wheels mounted on a vehicle;
• at least first and second ride height sensors for measuring the ride height of the vehicle whose alignment is to be measured, said ride height sensors outputting signals indicative of the ride height of first and second wheels of the vehicle whose alignment is to be measured, said ride height sensors including means for automatically determining when to output said signal;
• an electronic controller responsive to the acquired wheel alignment angle data and to the measured ride height for determining whether, taking into consideration the vehicle ride height, a measured wheel alignment angle falls within specifications;
• wherein said first and second wheels are disposed on an axle, and wherein each wheel alignment sensor includes a toe sensor, the controller being responsive to the toe sensors to compute total toe for that axle of said vehicle, and being responsive to the ride height sensors for each said wheel of said axle to determine the ride height of said wheels and to calculate an average ride height for said wheels.

A vehicle wheel alignment apparatus comprising:

• a storage device for storing vehicle wheel alignment angle specifications;
• at least one wheel alignment sensor for acquiring wheel alignment angle data of at least one wheel mounted on a vehicle;
• at least first and second ride height sensors for measuring the ride height of the vehicle whose alignment is to be measured, said at least one ride height outputting a signal indicative of the ride height of the wheel measured, said ride height sensor including means for automatically determining when to output said signal;
• an electronic controller responsive to the acquired wheel alignment angle data and to the measured ride height for determining whether, taking into consideration the vehicle ride height, a measured wheel alignment angle falls within specifications;
• at least a second ride height sensor, said controller being responsive to the ride height sensor measurements from the first and second ride height sensors to determine a front to back frame angle for the vehicle, further including at least a second wheel alignment sensor, said controller being responsive to the wheel alignment sensors to determine a caster angle and to adjust the caster angle as a function of the front to back frame angle.

A method of checking vehicle wheel alignment comprising the steps of:

• electronically storing vehicle wheel alignment angle specifications;
• electronically acquiring wheel alignment angle data of at least one wheel mounted on a vehicle;
• automatically electronically measuring the ride height of the vehicle whose alignment is to be measured;
• determining whether, as a function of the vehicle ride height, a measured wheel alignment angle falls within specifications;
• electronically computing total toe for the wheels of at least one axle of said vehicle, and electronically determining the ride height of said wheels;
• and
• calculating an average ride height for said wheels.

A method of checking vehicle wheel alignment comprising the steps of:

• electronically storing vehicle wheel alignment angle specifications:
• electronically acquiring wheel alignment angle data of at least one wheel mounted on a vehicle;
• automatically electronically measuring the ride height of the vehicle whose alignment is to be measured;
• determining whether, as a function of the vehicle ride height, a measured wheel alignment angle falls within specifications;
• wherein the step of electronically measuring the ride height includes making a first and a second ride height measurement at first and second vehicle wheels, said method further including determining from first and second ride height measurements a front to back frame angle for the vehicle, determining a caster angle, and adjusting the caster angle as a function of the front to back frame angle.

An apparatus which diagnoses vehicle wheel alignment and suspension problems, comprising:

• wheel alignment sensor means for acquiring wheel alignment angle data for a plurality of wheels mounted on a vehicle;
• ride height sensor means for measuring the ride height of the vehicle;
• jacking means for vertically moving the body of the vehicle with respect to the wheels to temporarily change the ride height of the vehicle;
• computer means operatively connected to the wheel alignment sensor means and the ride height sensor means and responsive to changes in measured wheel alignment angles with changes in measured ride height;
• said computer means including means for diagnosing vehicle alignment and suspension problems in response to said measured wheel alignment angles and measured ride height.

A method of diagnosing vehicle wheel alignment and suspension problems, comprising the steps off

• (a) electronically acquiring wheel alignment angle data for a plurality of wheels mounted on a vehicle;
• (b) electronically measuring the ride height of the vehicle;
• (c) vertically moving the body of the vehicle with respect to the wheels to temporarily change the ride height of the vehicle;
• (d) electronically acquiring wheel alignment angle data for the plurality of wheels while the ride height of the vehicle is changed;
• (e) comparing the wheel alignment data acquired in steps (a) and (d);
• and
• diagnosing vehicle alignment and suspension problems by examining changes in measured wheel alignment angles with changes in measured ride height.