Method and apparatus for controlling a sliding elevator door

A method for controlling a sliding elevator door, the door having at least one door leaf coupled to a door motor for driving the leaf between an open position and a closed position, a door drive including the door motor for controlling a driving force applied by the motor to the door leaf, and an emergency closing device including a closing weight connected to the door leaf, comprising the steps:

• a) moving a door leaf of a sliding door system in an opening learning travel by switching on a door motor coupled to the door leaf and accelerating the door leaf from a closed position to a predetermined opening speed, and switching the door motor off at said predetermined opening speed;
• b) detecting and storing a first speed and a first travel point of the door leaf at a beginning of a first test section and a second speed and a second travel point at an end of said first test section, said first test section beginning after the door motor is switched off;
• c) switching on the door motor to open the door leaf completely;
• d) moving the door leaf in a closing learning travel by switching on the door motor and accelerating the door leaf from an open position to a predetermined closing speed, and switching the door motor off at said predetermined closing speed;
• e) detecting and storing a third speed and a first travel point of the door leaf at a beginning of a second test section and a fourth speed and a second travel point at an end of said second test section, said second test section beginning after the door motor is switched off, said beginning and said end of said first test section being said end and said beginning respectively of said second test section;
• f) switching on the door motor to close the door leaf completely;
• g) determining a first energy balance of the sliding door system wherein a kinetic energy at the beginning of said first test section is equal to a kinetic energy at the end of said first test section plus a frictional energy generated by movement of the door leaf through said first test section plus a potential energy gained by a closing weight connected to the door leaf by movement of the door leaf through said first test section;
• h) determining a second energy balance of the sliding door system wherein a kinetic energy at the beginning of said second test section is equal to a kinetic energy at the end of said second test section plus a frictional energy generated by movement of the door leaf through said second test section minus a potential energy lost by the closing weight connected to the door leaf by movement of the door leaf through said second test section;
• and
• i) determining values for a dynamic mass and a mean frictional force for the sliding door system from said first and second energy balances.

An apparatus for operating a sliding elevator door, the door having at least one door leaf coupled to a door motor for driving the leaf between an open position and a closed position, a door drive including the door motor for controlling a driving force applied by the motor to the door leaf, an emergency closing device including a closing weight connected to the door leaf, the door drive including a microprocessor having an input, a tachometer coupled to the door motor for generating at an output pulses at a pulse frequency proportional to the speed of the door motor, the input of said microprocessor being connected to the output of the tachometer, the microprocessor having an output connected to the door motor for switching on and off the door motor, comprising:

• a microprocessor for controlling a door motor coupled to a door leaf of a sliding door system, the door motor driving the door leaf between an open position and a closed position, said microprocessor having an input for receiving a door motor speed signal from a tachometer coupled to the door motor;
• and
• a memory in said microprocessor responsive to said door motor speed signal for storing values of speeds and distances associated with a learning travel of the door leaf through a test section between the open position and the closed position of the door leaf whereby said microprocessor determines a first energy balance of the sliding door system for travel through a first test section, determines a second energy balance of the sliding door system for travel through a second test section, and determines values for a dynamic mass and a mean frictional force for the sliding door system from said first and second energy balances.