Electronic height control

A method for controlling a ride height in a suspension of an over the highway truck or tractor having a rear axle, said method comprising:

• a) measuring a load on said rear axle;
• b) measuring a speed of said over the highway truck or tractor;
• c) recording actual ride height values for a period of time;
• d) filtering said actual ride height values to remove a dynamic component of recorded ride height values;
• e) calculating a static ride height based on filtered ride height values;
• f) calculating an optimum ride height that corresponds to correct driveline angles based on said rear axle load;
• g) calculating a difference between said optimum ride height and said static ride height;
• and h) adjusting an amount of air in an air spring of said suspension to adjust said static ride height to a height closer to said optimum ride height.

An apparatus for controlling a ride height in a suspension of an over the highway truck or tractor having a rear axle, said method comprising:

• a) a pressure sensor for measuring a pressure in an air spring of said suspension to determine a load on said rear axle;
• b) an electronic control unit coupled to said sensor that calculates an optimum ride height that corresponds to correct driveline angles based on said rear axle load;
• c) a height sensor coupled to said electronic control unit for measuring an actual ride height, said electronic control unit calculates a difference between said optimum ride height and said actual ride height;
• and d) a valve coupled to said air spring and controlled by said electronic control unit to adjust an amount of air in said air spring to adjust said actual ride height to a height closer to said optimum ride height.

An apparatus for controlling the ride height in a suspension of an over the highway truck or tractor having a rear axle, said method comprising:

• a) an engine torque sensor;
• b) an acceleration sensor;
• c) an electronic control unit coupled to said sensor engine torque sensor and said acceleration sensor, said electronic control unit calculates a rear axle load based on input from said engine torque sensor and said acceleration sensor and calculates an optimum ride height that corresponds to correct driveline angles based on said rear axle load;
• d) a height sensor coupled to said electronic control unit for measuring an actual ride height of said over the highway truck or tractor, said electronic control unit calculates a difference between said optimum ride height and said actual ride height;
• and e) a valve coupled to said air spring and controlled by said electronic control unit to adjust an amount of air in said air-spring to adjust said actual ride height to a height closer to said optimum ride height.

A suspension assembly, comprising:

• a) a trailing arm;
• b) a hanger bracket attached to a vehicle frame member and a leading end of said trailing arm, said hanger bracket defining a pivot axis for said trailing arm;
• c) an air spring disposed between a spring seat attached to said trailing arm and said frame member;
• d) an axle attached to said trailing arm;
• e) a pressure sensor coupled to said air spring for measuring a pressure in said air spring to determine a load on said axle;
• f) an electronic control unit coupled to said pressure sensor that calculates an optimum ride height that corresponds to correct driveline angles based on said axle load;
• g) a height sensor coupled said frame member and said trailing arm, said height sensor provides a signal to said electronic control unit for determining an actual ride height, said electronic control unit calculates a difference between said optimum ride height and said actual ride height;
• and h) a valve coupled to said air spring and controlled by said electronic control unit to adjust an amount of air in said air spring to adjust said actual ride height to a height closer to said optimum ride height.

A suspension assembly, comprising:

• a) a trailing arm;
• b) a hanger bracket attached to a vehicle frame member and a leading end of said trailing arm, said hanger bracket defining a pivot axis for said trailing arm;
• c) an air spring disposed between a spring seat attached to said trailing arm and said frame member;
• d) an axle attached to said trailing arm;
• e) an engine torque sensor;
• f) an acceleration sensor;
• g) an electronic control unit coupled to said sensor engine torque sensor and said acceleration sensor, said electronic control unit calculates a rear axle load based on input from said engine torque sensor and said acceleration sensor and calculates an optimum ride height that corresponds to correct driveline angles based on said rear axle load;
• h) a height sensor coupled said frame member and said trailing arm, said height sensor provides a signal to said electronic control unit for determining an actual ride height, said electronic control unit calculates a difference between said optimum ride height and said actual ride height;
• and i) a valve coupled to said air spring and controlled by said electronic control unit to adjust an amount of air in said air spring to adjust said actual ride height to a height closer to said optimum ride height.