Example implementations relate to consensus protocols in a stretched network. According to an example, a distributed system includes continuously monitoring network performance and/or network latency among a cluster of a plurality of nodes in a distributed computer system. Leadership priority for each node is set based at least in part on the monitored network performance or network latency. Each node has a vote weight based at least in part on the leadership priority of the node. Each node's vote is biased by the node's vote weight. The node having a number of biased votes higher than a maximum possible number of votes biased by respective vote weights received by any other node in the cluster is selected as a leader node.

Example implementations relate to consensus protocols in a stretched network. According to an example, a distributed system includes continuously monitoring network performance and/or network latency among a cluster of a plurality of nodes in a distributed computer system. Leadership priority for each node is set based at least in part on the monitored network performance or network latency. Each node has a vote weight based at least in part on the leadership priority of the node. Each node's vote is biased by the node's vote weight. The node having a number of biased votes higher than a maximum possible number of votes biased by respective vote weights received by any other node in the cluster is selected as a leader node.

In a self-driving autonomous vehicle, a controller architecture includes multiple processors within the same box. Each processor monitors the others and takes appropriate safe action when needed. Some processors may run dormant or low priority redundant functions that become active when another processor is detected to have failed. The processors are independently powered and independently execute redundant algorithms from sensor data processing to actuation commands using different hardware capabilities (GPUs, processing cores, different input signals, etc.). Intentional hardware and software diversity improves fault tolerance. The resulting fault-tolerant/fail-operational system meets ISO26262 ASIL-D specifications based on a single electronic controller unit platform that can be used for self-driving vehicles.

The invention relates to this method comprising the following steps, for at least one input/output parameter: duplicating and inserting a list of graphical commands associated with said parameter within a calculation module of said chain, from a current value of said parameter, obtaining a current cyclic redundancy code associated with a current micropattern, generated by executing said at least one list, comparing said current cyclic redundancy code with a reference cyclic redundancy code stored in a dedicated memory space for a substantially identical value of said parameter within a tolerance threshold, in the event of a difference in cyclic redundancy code value, automatic sanctioning of said chain at least by suspending its execution.

In one embodiment, a multiplex control device includes three or more control modules to execute same operations for same input signals, and a majority decision module to output an output signal that matches majority of output signals outputted by the control modules. Each control module includes an input module to convert an input signal into an input value, a first determination module to obtain input values from input modules of respective control modules to determine whether majority of input values among the obtained input values match, an operation executing module to execute an operation using the matched input value to generate an output value, a second determination module to obtain output values from operation executing modules of respective control modules to determine whether majority of output values among the obtained output values match, and an output module to convert the matched output value to generate an output signal.

A control apparatus includes a first controller configured to generate control signals for controlling an engine or other machine, a second controller configured to generate the control signals for controlling the machine, a transfer circuit, and an arbiter circuit. The transfer circuit is coupled between the machine and the controllers, and is configured to switch from a first state, where the transfer circuit passes the control signals from the first controller to the machine, to a second state, where the transfer circuit passes the control signals from the second controller to the machine, responsive to receiving a first failure signal from the first controller. The arbiter circuit includes three (or more) arbiters, and is configured to control the transfer circuit from the first state to the second state responsive to any two of the three arbiters generating second signals indicative of failure of the first controller.

Example implementations relate to consensus protocols in a stretched network. According to an example, a distributed system includes continuously monitoring network performance and/or network latency among a cluster of a plurality of nodes in a distributed computer system. Leadership priority for each node is set based at least in part on the monitored network performance or network latency. Each node has a vote weight based at least in part on the leadership priority of the node. Each node's vote is biased by the node's vote weight. The node having a number of biased votes higher than a maximum possible number of votes biased by respective vote weights received by any other node in the cluster is selected as a leader node.

In a self-driving autonomous vehicle, a controller architecture includes multiple processors within the same box. Each processor monitors the others and takes appropriate safe action when needed. Some processors may run dormant or low priority redundant functions that become active when another processor is detected to have failed. The processors are independently powered and independently execute redundant algorithms from sensor data processing to actuation commands using different hardware capabilities (GPUs, processing cores, different input signals, etc.). Intentional hardware and software diversity improves fault tolerance. The resulting fault-tolerant/fail-operational system meets ISO26262 ASIL D specifications based on a single electronic controller unit platform that can be used for self-driving vehicles.

The voter circuit and method determines a voted output among plural inputs each carrying circular data. To supply the voted output, a statistical average (e.g., mean or median) is computed by grouping the plural inputs into pairs, and for each pair generating a minimum angular difference by selecting the minimum of (a) the absolute difference between the pairs of inputs, and (b) the conjugate of the absolute difference between the pairs of inputs. The voted output is a statistical average generated from the minimum angular difference.

The voter circuit and method determines a voted output among plural inputs each carrying circular data. To supply the voted output, a statistical average (e.g., mean or median) is computed by grouping the plural inputs into pairs, and for each pair generating a minimum angular difference by selecting the minimum of (a) the absolute difference between the pairs of inputs, and (b) the conjugate of the absolute difference between the pairs of inputs. The voted output is a statistical average generated from the minimum angular difference.