Abstract: Heat pump systems and methods of operating including a first unit having a first unit heat exchanger, a compressor, an accumulator, and a first unit expansion valve, a second unit fluidly connected to the first unit by piping, the second unit having a second unit heat exchanger, and a system controller, the system controller having (I) a PID control element receiving as inputs (i) gain scheduling, (ii) an error signal, and (iii) feedback relating to an opening command of the first unit expansion valve, and (II) a feedforward control element generating a feedforward term that is combined with an output of the PID control element to generate the opening command of the first unit expansion valve. The system controller controls an opening of the first unit expansion valve using the opening command of the first unit expansion valve.

Abstract: The present disclosure describes systems and apparatuses for connecting graphical shapes. A client digital data processor receives selection events. Each selection event tracks one or more input locations. The client digital data processor identifies a source and target graphical shape based at least on the received selection events. The client digital data processor determines a source and target connection point for a connector based at least on the source and target graphical shapes. The client digital data processor determines a length for the connector based at least on the source and target connection points. The client digital data processor generates and displays the connector based at least on the source and target connection points and the length. The present disclosure also describes methods for operating a client digital data processor as described above, and a computer-readable medium storing a program having instructions for so operating a client digital data processor.

Abstract: Heat pump systems and methods of operating including a first unit having a first unit heat exchanger, a compressor, an accumulator, and a first unit expansion valve, a second unit fluidly connected to the first unit by piping, the second unit having a second unit heat exchanger, and a system controller, the system controller having (I) a PID control element receiving as inputs (i) gain scheduling, (ii) an error signal, and (iii) feedback relating to an opening command of the first unit expansion valve, and (II) a feedforward control element generating a feedforward term that is combined with an output of the PID control element to generate the opening command of the first unit expansion valve. The system controller controls an opening of the first unit expansion valve using the opening command of the first unit expansion valve.

Abstract: The present disclosure describes systems and apparatuses for connecting graphical shapes. A client digital data processor receives selection events. Each selection event tracks one or more input locations. The client digital data processor identifies a source and target graphical shape based at least on the received selection events. The client digital data processor determines a source and target connection point for a connector based at least on the source and target graphical shapes. The client digital data processor determines a length for the connector based at least on the source and target connection points. The client digital data processor generates and displays the connector based at least on the source and target connection points and the length. The present disclosure also describes methods for operating a client digital data processor as described above, and a computer-readable medium storing a program having instructions for so operating a client digital data processor.