Method and system for fail-safe control of electric actuators
Assignee1593417 Alberta Ltd.
InventorsGarth Steven Hanson, Thomas Joseph MacArthur, Henri Richard Tessier
Life of this patent
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Abstract
A method and system are provided for supplying back-up electric power to an electric actuator powered by a supply of main electric power, and to interrupt or to replace a control signal supplied to the actuator so that the actuator can be reverted to a fail-safe mode, condition or position when there is a failure or disruption of the main electric power or when the control signal is not within the accepted pre-determined standard or range for the control signal.
Claims18
A method for controlling one or more of a plurality of electric actuators in the event of an interruption of a supply of main electric power operatively coupled to an electric power input disposed on each of the plurality of electric actuators, each of the plurality of electric actuators comprising an actuator control signal input disposed thereon, wherein the actuator control signal input is operatively coupled to an actuator controller, the actuator controller configured to control the plurality of electric actuators with an actuator control signal supplied to the actuator control signal input, the method comprising the steps of:
- (a) monitoring a heartbeat signal supplied to the plurality of electric actuators with a main control unit, the heartbeat signal configured to command the plurality of electric actuators to stay open or to remain in place;
- (b) supplying an alternate source of electric power to the electric power input when the supply of main electric power is interrupted;
- (c) monitoring the alternate source of electric power;
- and
- (d) disconnecting the actuator control signal from the actuator control signal input of the plurality of electric actuators or supplying a fail-safe command signal to the actuator control signal input of the plurality of electric actuators when the supply of main electric power is interrupted and when the alternate source of electric power is in an error condition, wherein the disconnecting of the actuator control signal, or the supplying of the fail-safe command signal, to the actuator control signal input of the plurality of electric actuators is sequenced to stagger the operation of the plurality of electric actuators thereby limiting peak current required to move all of the plurality of electric actuators to a fail-safe position.
A system for controlling one or more of a plurality of electric actuators in the event of an interruption of a supply of main electric power operatively coupled to an electric power input disposed on each of the plurality of electric actuators, each of the plurality of electric actuators comprising an actuator control signal input disposed thereon, wherein the actuator control signal input is operatively coupled to an actuator controller, the actuator controller configured to control the plurality of electric actuators with an actuator control signal supplied to the actuator control signal input, the system comprising:
- (a) a main control unit configured to supply an alternate source of electric power to the electric power input when the supply of main electric power is interrupted, the main control unit further configured to monitor the alternate source of electric power, the main control unit further configured to monitor a heartbeat signal supplied to the plurality of electric actuators by the actuator controller, the heartbeat signal configured to command the plurality of electric actuators to stay open or to remain in place;
- (b) a control signal interface unit configured to disconnect the actuator control signal from the actuator control signal input of the plurality of electric actuators or to supply a fail-safe command signal to the actuator control signal input of the plurality of electric actuators when the supply of main electric power is interrupted and when the alternate source of electric power is in an error condition;
- and
- (c) a sequencer configured to sequence the disconnection of the actuator control signal, or to supply the fail-safe command signal, to the actuator control signal input of the plurality of electric actuators to stagger the operation of the plurality of electric actuators thereby limiting peak current required to move all of the plurality of electric actuators to a fail-safe position.
Dependencies are inferred from the claim text.