Systems and methods for monitoring elevator dual coil electromechanical brakes

A system for monitoring operating conditions of an elevator braking assembly of an elevator assembly, the elevator assembly further including an elevator controller, an elevator cab and at least one traction sheave having the braking assembly coupled thereto, the elevator braking system having at least one mobile plate and a coil that when energized moves the at least one mobile plate from an engaged position to inhibit movement of the at least one traction sheave to a disengaged position, an elevator hoisting member extending around the at least one traction sheave to support the elevator cab, and the elevator controller configured to control the at least one traction sheave to move the elevator hoisting member to move the elevator cab, the system comprising:

• a processing device communicatively coupled to the elevator controller;
• and
• a non-transitory, processor-readable storage medium in communication with the processing device and having one or more programming instructions that, when executed, cause the processing device to:
• receive an actual braking current data from the elevator braking assembly that is filtered and converted to digital signals;
• determine a derivative of the digital signals;
• plot a derivative curve of the determined derivative of the digital signals indicative of the actual braking current data;
• determine a region of interest of the derivative curve that corresponds to an expected movement of at least one mobile plate of the elevator braking assembly;
• determine whether a pair of inflection points occurred during the region of interest where one of the inflection points is a minimum point and the other is a maximum point, the maximum point having a greater value than the minimum point and occurring after the occurrence of the minimum point;
• and
• when the pair of inflection points does not occur during the region of interest of the derivative curve, output an alert to the elevator controller to instruct the elevator controller to inhibit movement of the elevator cab.

A method for monitoring operating conditions of an elevator braking assembly of an elevator assembly, the elevator assembly further including an elevator controller, an elevator cab and at least one traction sheave having the braking assembly coupled thereto, the elevator braking system having at least one mobile plate and a coil that when energized moves the at least one mobile plate from an engaged position to inhibit movement of the at least one traction sheave to a disengaged position, an elevator hoisting member extending around the at least one traction sheave to support the elevator cab, and the elevator controller configured to control the at least one traction sheave to move the elevator hoisting member to move the elevator cab, the method comprising:

• receiving an actual braking current data from the elevator braking assembly;
• determining a derivative of the actual braking current data;
• plotting a derivative curve of the derivative of the actual braking current data;
• determine a region of interest of the derivative curve that corresponds to an expected movement of the at least one mobile plate of the elevator braking assembly;
• determining whether a pair of inflection points occurred during the region of interest where one of the inflection points is a minimum point and the other is a maximum point, the maximum point having a greater value than the minimum point and occurring after the occurrence of the minimum point;
• and
• when the pair of inflection points does not occur during the region of interest of the derivative curve, outputting an alert to the elevator controller to instruct the elevator controller to inhibit movement of the elevator cab.