Abstract:
The present disclosure provides a secure one-step IEEE 1588 clock using either a symmetric or asymmetric protection scheme. Clocks of mission-critical or highly-available devices in industrial automation systems connected to a communication network are synchronized by sending, by a master clock, a synchronization message, e.g., a single message of the one-step-clock type according to IEEE 1588, including a time stamp, and by receiving and evaluating, by a slave clock, the synchronization message. A synchronization component or module of the master clock prepares, or composes, prior to a projected send time, a synchronization message including a time stamp of the projected send time, and secures the synchronization message in advance of the projected send time. Securing the synchronization message occurs by suitable cryptographic means allowing for authentication of the time stamp at a receiving slave clock. At the projected send time, the secured synchronization message is transmitted.
Abstract:
Exemplary embodiments are directed to a communication network interconnecting a plurality of synchronized nodes, where regular frames including time-critical data are transmitted periodically or cyclically, and sporadic frames are transmitted non-periodically or occasionally. For example, each node can transmit a regular frame at the beginning of a transmission period common to, and synchronized among, all nodes. Another node then receives regular frames from its first neighboring node, and forwards the frames within the same transmission period and with the shortest delay, to a second neighboring node. Furthermore, each node actively delays transmission of any sporadic frame, whether originating from an application hosted by the node itself or whether received from a neighboring node, until forwarding of all received regular frames is completed.
Abstract:
The present disclosure provides a secure one-step IEEE 1588 clock using either a symmetric or asymmetric protection scheme. Clocks of mission-critical or highly-available devices in industrial automation systems connected to a communication network are synchronized by sending, by a master clock, a synchronization message, e.g., a single message of the one-step-clock type according to IEEE 1588, including a time stamp, and by receiving and evaluating, by a slave clock, the synchronization message. A synchronization component or module of the master clock prepares, or composes, prior to a projected send time, a synchronization message including a time stamp of the projected send time, and secures the synchronization message in advance of the projected send time. Securing the synchronization message occurs by suitable cryptographic means allowing for authentication of the time stamp at a receiving slave clock. At the projected send time, the secured synchronization message is transmitted.
Abstract:
Techniques are disclosed for performing the estimation and/or prediction of the dynamic system state of large power system networks, using a multi-processor approach. More particularly, a large power system network is divided into smaller sub-systems, each sub-system having associated dynamic state variables. Each sub-system is assigned to one or more of a plurality of processing elements, and dynamic state variables for each sub-system are estimated or predicted independently, using the processing elements and sensor measurements. In several embodiments, the dynamic state of each sub-system is computed through the construction of a set of dedicated observers, such as linear parameter-varying (LPV) observers, which are designed to reduce the effects of other sub-systems on the state estimation problem.
Abstract:
Exemplary embodiments are directed to a communication network interconnecting a plurality of synchronized nodes, where regular frames including time-critical data are transmitted periodically or cyclically, and sporadic frames are transmitted non-periodically or occasionally. For example, each node can transmit a regular frame at the beginning of a transmission period common to, and synchronized among, all nodes. Another node then receives regular frames from its first neighboring node, and forwards the frames within the same transmission period and with the shortest delay, to a second neighboring node. Furthermore, each node actively delays transmission of any sporadic frame, whether originating from an application hosted by the node itself or whether received from a neighboring node, until forwarding of all received regular frames is completed.
Abstract:
Techniques are disclosed for performing the estimation and/or prediction of the dynamic system state of large power system networks, using a multi-processor approach. More particularly, a large power system network is divided into smaller sub-systems, each sub-system having associated dynamic state variables. Each sub-system is assigned to one or more of a plurality of processing elements, and dynamic state variables for each sub-system are estimated or predicted independently, using the processing elements and sensor measurements. In several embodiments, the dynamic state of each sub-system is computed through the construction of a set of dedicated observers, such as linear parameter-varying (LPV) observers, which are designed to reduce the effects of other sub-systems on the state estimation problem.