Peculiarities of organizing computational process in on-board computer systems based on digital-platform design

Computational process is organized with Information Transporting Service System (ITSS).

The functions of ITSS are:

1) ruling computational process and communications;

2) controlling hardware operability during all stages of its lifecycle;

3) providing resiliency and reliable functioning of the system;

4) providing technological facilities for desinging and debugging software;

5) software verification on earth-based quality-control stations.

The following aims were pointed during the design of the structure of computational process in controlling systems of a spacecraft:

1) providing the guaranteed strict real-time;

2) possible re-usage of already developed software for similar systems;

3) increasing the hardware-independency;

4) a possibility to reconfigure the system;

5) an ability of the system to function either in RTOS environment, or separately without any OS;

6) lowering the cost of software design, modification, support and maintainance.

We choose blackboard systems as a basis of our system. The main elements in computational process organization are:

- network objects database

- control-flows (each software component is functioning in the control-flow mode). A control-flow is a unit of multi-program control;

- drivers (software components which interact with I/O devices);

- controlling program.