Method for controlling and automatically restarting a technical apparatus

A real-time computer system for controlling a technical apparatus, wherein the real-time computer system comprises:

• subsystems, wherein the subsystems are arranged hierarchically,
• wherein the subsystems are synchronized via a global time by using a time server (210), which is preferably positioned outside the hierarchy of the subsystems, wherein the time server (210) is set up to periodically send synchronization messages (211) to each subsystem, including to the clocks of each subsystem, for synchronizing the subsystems or the clocks of the subsystems for establishing the global time,
• wherein using this global time, the timeline is divided into a sequence of synchronized time slices,
• wherein each subsystem (100, 110, 120, 130) and, if present, the time server (210), forms its own Fault-Containment Unit,
• wherein one of the subsystems is a decision subsystem, the so-called Fault-Tolerant Decision Subsystem, FTDSS, (100), which is positioned at the highest level of the hierarchy, wherein the FTDSS (100) is set up to transfer setpoints to actuators (150) during each time slice by means of messages (101), wherein the Fault-Tolerant Decision Subsystem, FTDSS, (100) is a secure subsystem comprising simple software executed on fault-tolerant hardware,
• wherein at least or exactly three Data Processing Subsystems, a Normal Processing Subsystem, NPSS, (110), a Monitor Subsystem, MSS, (120), and a Critical Event Handling Subsystem, CEHSS, (130), are provided, all of which are positioned at the next lower hierarchical level, wherein these at least or exactly three Data Processing Subsystems are set up to capture sensor data by means of sensors (160) from an environment observed by the sensors (160) and to evaluate these sensor data independently of each other,
• wherein the environment is observed by the Data Processing Subsystems (110, 120, 130) at the beginning of each time slice and calculations are carried out during this time slice with the sensor data obtained from the observations of the environment carried out at the beginning of said time slice, and wherein:
• i. the Normal Processing Subsystem, NPSS, (110) is set up to send a set of setpoints for normal operation to the Fault-Tolerant Decision Subsystem, FTDSS, (100) in a message (111) and to the Monitor Subsystem, MSS, (120) in a message (112) during each time slice, at the end of the time slice,
• ii. the Critical Event Handling Subsystem, CEHSS, (130) is set up to send a set of setpoints for an abnormal operation to the Fault-Tolerant Decision Subsystem, FTDSS, (100) in a message (131) during each time slice, at the end of said time slice, and wherein the CEHSS (130) is set up to communicate to the FTDSS (100), in said message (131), whether the technical apparatus is in a safe state,
• iii. the Fault-Tolerant Decision Subsystem, FTDSS, (100) is set up to send the received set of setpoints for normal operation to the Monitor Subsystem, MSS, (120) in a message (102) during each time slice, and wherein the Fault-Tolerant Decision Subsystem, FTDSS, (100) is set up to furthermore send the received set of setpoints for abnormal operation to the Monitor Subsystem, MSS, (120) in a message (102) during each time slice, at the end of said time slice, and
• iv. the Monitor Subsystem, MSS, (120) is set up to carry out a review during each time slice whether the set of setpoints for normal operation, which it received from the Normal Processing Subsystem, NPSS, (110) in the message (112), is compatible with an environmental model calculated by the MSS (120) on the basis of the sensor data (160) from the MSS (120) and ensures safe control of the technical apparatus under normal conditions, and furthermore the Monitor Subsystem, MSS, (120) is set up to carry out a review during each time slice whether the set of setpoints for normal operation, which it received from the Normal Processing Subsystem, NPSS, (110) in said message (112), is identical to the corresponding set of setpoints sent by the Normal Processing Subsystem, NPSS, (110) to the Monitor Subsystem, MSS, (120) via the Fault-Tolerant Decision Subsystem, FTDSS, (100), and
• wherein if both reviews are positive, to set a correctness indicator, correctness indicator-1, to the value TRUE and, if one of the two checks is negative or both checks are negative, to set the correctness indicator-1 to the value FALSE and to send the correctness indicator-1 or the value of the correctness indicator-1 to the Fault-Tolerant Decision Subsystem, FTDSS, (100) in a message (121) during each time slice, and
• wherein the Fault-Tolerant Decision Subsystem, FTDSS, (100) makes a decision as follows during each time slice:
• in the event that the correctness indicator-1 is TRUE, the set of setpoints for normal operation is transferred to the actuators (150), for example in messages (101);
• in the event that the correctness indicator-1 has a value of FALSE or if a message (121) with the correctness indicator-1 expected by the FTDSS (100) is missing, the set of setpoints for abnormal operation is forwarded to the actuators (150), for example in messages (101), wherein, in this case, the setpoints for abnormal operation are forwarded to the actuators (150) during the time slices following that point in time until the technical apparatus reaches a safe state, which is communicated to the FTDSS (100) by the CEHSS, preferably in the message (131),
• wherein the Fault-Tolerant Decision Subsystem, FTDSS, (100) is set up send the setpoints forwarded to the actuators (150) to the NPSS (110) and to the MSS (120) in messages (401, 402) during each time slice,
• wherein in the event that the NPSS (110) and/or MSS (120), based on the review of the setpoints contained in the messages (401, 402), determine that the FTDSS (100) has forwarded the setpoints for abnormal operation to the actuators (150), a restart of the MSS (120) and NPSS (110) is triggered,
• wherein the restart is completed as soon as
• the FTDSS (100), based on the content of the message (131) from the CEHSS (130), in which the CEHSS (130) communicates whether the technical apparatus is in a safe state, determines that the system is in a safe state, and
• the FTDSS (100), receives a set of setpoints for normal operation from the NPSS (110) during a time slice, for example, in a message (111), and
• the FTDSS (100) receives the correctness indicator-1 with a value of TRUE from the MSS (120), for example with a message (121), during said time slice,
• wherein, after completion of the restart, the FTDSS (100) again transfers the setpoints for normal operation received from the NPSS (110) to the actuators, such that steps i.-iv. can be carried out again or are carried out, and
• wherein restarting the two data processing subsystems, namely the NPSS (110) and the MSS (120), each comprises the following steps:
• a) resetting the hardware of the data processing subsystem,
• b) executing a test software for determining the integrity of the data processing subsystem,
• c) reinitializing and restarting the software of the data processing subsystem,
• d) performing calculations with the sensor data obtained from observations of the environment made at the beginning of a time slice.