Electronic line shaft

An assembly for synchronizing machine operations, the assembly comprising:

• a reference generator for generating a speed reference signal and a position reference signal;
• a plurality of slave units, each slave unit including:
• a mechanical device;
• a separate motor linked to and driving the mechanical device;
• an encoder for generating an encoder signal usable to identify the rotational position of at least one of the mechanical device and the motor;
• a separate unit controller for controlling the unit motor, the unit controller receiving and using the reference signals and the encoder signals to control motor operation, the unit controller including an inertia adaptation unit that receives the encoder signal and uses the encoder signal to modify motor control as a function of load inertia;
• and
• a synchronizer receiving the reference signals from the control signal source and simultaneously providing the reference signals to each of the slave unit controllers for use in controlling operation of the motors in a synchronized fashion.

An assembly for synchronizing machine operations, the assembly comprising:

• a reference generator for generating a speed reference signal and a position reference signal;
• a plurality of slave units, each slave unit including:
• a mechanical device;
• a separate motor linked to and driving the mechanical device;
• an encoder for generating an encoder signal usable to identify the rotational position of at least one of the mechanical device and the motor;
• a separate unit controller for controlling the unit motor, the unit controller receiving and using the reference signals and the encoder signals to control motor operation, the unit controller including an inertia adaptation unit that receives the encoder signal and uses the encoder signal to modify motor control as a function of load inertia;
• and
• a synchronizer receiving the reference signals from the control signal source and simultaneously providing the reference signals to each of the slave unit controllers for use in controlling operation of the motors in a synchronized fashion, the synchronizer generating and providing periodic synchronization signals to the unit controllers indicating times at which the reference signals are to be used by the unit controllers to control motor operation.

A method for synchronizing operations of units where each unit includes a mechanical device, a separate motor linked to and driving the mechanical device and a separate unit controller for controlling the unit motor, the method comprising the steps of:

• generating a master speed reference signal and a master position reference signal;
• transmitting the speed and position reference signals to the unit controllers;
• storing the received reference signals at the unit controllers;
• periodically providing synchronization signals to each of the unit controllers;
• when a synchronization signal is received at a unit controller, causing the unit controller to control operation of an associated unit motor as a function of the received reference signals.

A method for synchronizing operations of units where each unit includes a mechanical device, a separate motor linked to and driving the mechanical device and a separate unit controller for controlling the unit motor, the method comprising the steps of:

• providing position feedback signals to each of the unit controllers that indicate the instantaneous position of at least one of the mechanical device and the motor in an associated unit;
• using the position feedback signals to identify a load inertia estimate;
• simultaneously releasing speed and position reference signals to each of the unit controllers for controlling the unit motors;
• upon release of the reference signals, causing each unit controller to use each of the reference signals and the load inertia estimate to control unit motor operation.