Method and apparatus for determination of slot-duration in time-triggered control system

A method for determining an optimal duration of a time slot for computational actions in a time-triggered controller comprising a sensor subsystem, a computational subsystem, an actuator subsystem, and a time-triggered communication system in which the time-triggered communication system is between the sensor subsystem, the computational subsystem, the actuator subsystem, and a monitor subsystem, the method comprising:

• routing outgoing messages of the sensor subsystem to the computational subsystem and the monitor subsystem via the time-triggered communication system;
• routing outgoing messages of the computational subsystem to the actuator subsystem and the monitor subsystem via the time-triggered communication system;
• executing anytime algorithms in the computational subsystem;
• probing a plurality of execution slot durations of the anytime algorithms during a development phase, starting from a minimum execution slot duration and increasing therefrom by an execution slot granularity until a maximum execution slot duration is reached;
• executing, in the plurality of execution slot durations, a multitude of frames in a destined application environment;
• calculating, in each frame of the multitude of frames by the computational subsystem, imprecise anticipated values of observable state variables by interrupting the execution of the anytime algorithms at an end of one of the execution slot durations, using data received from the sensor subsystems at a beginning of a frame of the multitude of frames;
• calculating, in each frame of the multitude of frames by the monitor subsystem, precise anticipated values of observable state variables by executing the anytime algorithms until completion using data received from the sensor subsystems at the beginning of the frame;
• computing, by the monitor subsystem, an anytime-algorithm impreciseness by calculating absolute values of the difference between the precise anticipated values of observable state variables and the imprecise anticipated values of observable state variables contained in the outgoing messages delivered from the computational subsystems to the monitor subsystem at an end of the frame;
• computing, by the monitor subsystem, a model error by calculating the absolute values of the difference between the precise anticipated values of observable state variables and the respective acquired values of observable state variables contained in the outgoing messages from the sensor subsystem to the monitor subsystem at the end of the frame;
• calculating an average anytime-algorithm impreciseness and an average model error of a slot duration by the monitor subsystem by averaging results of a multitude of probed frames of the slot duration;
• and
• selecting, at the end of the development phase, an execution slot duration for the computational subsystem out of the probed execution slot durations, wherein a sum of the average model error and the average anytime-algorithm impreciseness is minimal.