Method and apparatus for synchronizing a vehicle lift

A controller for a vehicle lift, said vehicle lift having a first vertically moveable superstructure and a second vertically moveable superstructure, each of said first and second vertically moveable superstructures having respective vertical positions which vary when said first and second vertically moveable superstructures are respectively moved, said controller comprising:

• a. an interface configured to receive a first position signal indicative of the vertical position of said first vertically moveable superstructure and a second position signal indicative of the vertical position of said second vertically moveable superstructure;
• b. a raise circuit responsive to said first and second position signals and to a vertical trajectory signal and operably configured to generate a first raise signal for said first vertically moveable superstructure and to generate a second raise signal for said second vertically moveable superstructure.

A vehicle lift having a first pair formed of a first vertically moveable superstructure and a second vertically moveable superstructure, each of said first and second vertically moveable superstructures having respective vertical positions which vary when said first and second vertically moveable superstructures are respectively moved, said vehicle lift comprising:

• a. a first circuit operably configured to generate a first position signal indicative of the vertical position of said first vertically moveable superstructure;
• b. a second circuit operably configured to generate a second position signal indicative of the vertical position of said second vertically moveable superstructure, and
• c. a third circuit operably configured to generate a first raise signal for said first vertically moveable superstructure and to generate a second raise signal for said second vertically moveable superstructure, said first and second raise signals respectively being functions of said first and second position signals and a vertical trajectory signal.

A controller for a vehicle lift, said vehicle lift having a first pair formed of a first vertically moveable superstructure and a second vertically moveable superstructure, each of said first and second vertically moveable superstructures having respective vertical positions which vary when said first and second vertically moveable superstructures are respectively moved, said controller comprising:

• a. a first feedback control loop operably configured to command said first and second vertically moveable superstructures to a vertical trajectory;
• and
• b. a first differential feedback control loop operably configured to synchronize movement of said first and second vertically moveable superstructure.

A vehicle lift comprising:

• a. a first vertically moveable superstructure having a variable vertical position;
• b. a second vertically moveable superstructure having a variable vertical position, and
• c. a controller operably configured to synchronize vertical actuation of said first and second vertically moveable superstructures by determining a proportional-integral error signal relative to the respective vertical positions of said first and second vertically moveable superstructures.

A controller for a vehicle lift, said vehicle lift having a first pair formed of a first vertically moveable superstructure and a second vertically moveable superstructure, each of said first and second vertically moveable superstructures having respective vertical positions which vary when said first and second vertically moveable superstructures are respectively moved, said controller comprising:

• a. an interface configured to receive a first position signal indicative of the vertical position of said first vertically moveable superstructure and a second position signal indicative of the vertical position of said second vertically moveable superstructure;
• and
• b. a first circuit operably configured to generate a vertical trajectory signal for said first and second vertically moveable structures.

A controller for a vehicle lift, said vehicle lift having a first pair formed of a first vertically moveable superstructure and a second vertically moveable superstructure, a second pair formed of a third vertically moveable superstructure and a fourth vertically moveable superstructure, each of said vertically moveable superstructures having respective vertical positions which vary when said vertically moveable superstructures are respectively moved, said controller configured to synchronize the first and second pairs relative to each other by determining a lift proportional-integral error signal for a sum of the vertical positions of said first and second vertically moveable superstructures relative to a sum of the vertical positions of said third and fourth vertically moveable superstructures.