Elevator door control responsive to obstructions

An apparatus for automatically operating car doors in an elevator system having a door operating apparatus which moves door leaves of a car door by means of a door motor and door leaves of a shaft door by way of entraining members on the car door leaves between a closed end position and an open end position and which permits the car door leaves to stop in any position between the end positions, move further in the same direction or reverse, comprising:

• a microprocessor control for storing a target speed signal and having an input and an output;
• an electronic switching system having an input connected to said output of said microprocessor control and an output;
• a direct current motor connected to said output of said electronic switching circuit and mechanically coupled to drive elevator car door leaves;
• a digital tachometer mechanically coupled to said motor and having an output connected to said input of said microprocessor control for generating an actual speed signal representing the instantaneous speed of said motor to said microprocessor control whereby said microprocessor control is responsive to said target speed signal and said actual speed signal for generating a regulating error difference signal "dV" produced by an external interference force acting upon the car door leaves of the closing elevator door, for comparing a value of said difference signal "dV" with a value of a predetermined tolerance signal "dVmax" and for initiating stopping and reversing of direction of the closing car door leaves by controlling said electronic switching system and said motor when a value of said difference signal "dV" exceeds a value of said predetermined tolerance signal "dVmax";
• and
• said microprocessor control including a target value generator for generating a plurality of different target speed signals and having a pair of inputs and a pair of outputs, a first subtractor having an input connected to one of said outputs of said target value generator and having another input and an output, a travel curve selector for connecting one of said target speed signals to said one output of said target value generator, a difference value generator having an input connected to said output of said first subtractor and a pair of outputs, a limit value comparator having an input connected to one of said outputs of said difference value comparator and another input connected to the other one of said outputs of said target value generator and an output connected to an elevator control, a second subtractor having an input connected to the other one of said outputs of said difference value generator and having another input and an output, a regulator connected between said output of said second subtractor and said input of said electronic switching system, a learning travel computer having an input and three outputs, one of said outputs being connected to one of said inputs of said target value generator, a learning travel selector connected between said output of said digital tachometer and said input of said learning travel computer, another subtractor having a pair of inputs connected to the other two of said three outputs of said learning travel computer and an output connected the other one of said inputs of said second subtractor, a digital filter connected between said output of said digital tachometer and the other one of said inputs of said first subtractor, and an integrator connected between said output of said digital tachometer and the other one of said inputs of said target value generator.

An apparatus for automatically operating car doors in an elevator system having a door operating apparatus which moves door leaves of a car door by means of a door motor and door leaves of a shaft door by way of entraining members on the car door leaves between a closed end position and an open end position and which permits the car door leaves to stop in any position between the end positions, move further in the same direction or reverse, comprising:

• a microprocessor control for storing a target speed signal and having an input and an output;
• an electronic switching system having an input connected to said output of said microprocessor control and an output;
• a direct current motor connected to said output of said electronic switching circuit and mechanically coupled to drive elevator car door leaves;
• a digital tachometer mechanically coupled to said motor and having an output connected to said input of said microprocessor control for generating an actual speed signal representing the instantaneous speed of said motor to said microprocessor control whereby said microprocessor control is responsive to said target speed signal and said actual speed signal for generating a regulating error difference signal "dV" produced by an external interference force acting upon the car door leaves of the closing elevator door, for comparing a value of said difference signal "dV" with a value of a predetermined tolerance signal "dVmax" and for initiating stopping and reversing of direction of the closing car door leaves by controlling said electronic switching system and said motor when a value of said difference signal "dV" exceeds a value of said predetermined tolerance signal "dVmax";
• and
• wherein said microprocessor control includes a filter, a divider and an inverter connected in series, at least one target speed signal is stored in said microprocessor control as a series of straight lines connected by break points and is passed through said filter to generate said one target speed signal at said one output of said target value generator, said one target speed signal is passed through said divider to generate said predetermined tolerance signal "dVmax" having a positive value and said predetermined tolerance signal is passed through said inverter to generate said predetermined tolerance signal "dVmax" having a negative value.