An Improved Small Satellite Data Transmission Subsystem Bus Scheduling System

Abstract

The present invention provides an improved small satellite data transmission subsystem bus dispatching system, and relates to the field of small satellite data transmission subsystem bus dispatching.The system comprises a data transmission control unit and n lower level devices, wherein the data transmission control unit comprises a main program module, an upper-level bus triggering interruptionmodule and a lower-level bus triggering interruption module; the upper-level bus triggering interrupting module comprises an upper-level processing return starting module and a processing response forwarding module; each lower level device comprises one device return starting module and one device response module; and the main program module comprises a retransmission module and a framing packingmodule. The improved small satellite data transmission subsystem bus dispatching system employs event triggering to replace the internal timer triggering to solve the phenomena of loss and repeating of telemetering frames caused by each independent clock and achieve common clock of a multi-level bus; response and re-transmission mechanisms are added to improve the success rate, the robustness andreliability of the communication; and moreover, the improved small satellite data transmission subsystem bus dispatching system has good expansibility, can be used for design of the satellite data transmission subsystem and can support the multi-bus design of the distributed system.

Description

technical field [0001] The invention relates to the field of bus dispatching of a small satellite data transmission subsystem, in particular to an improved bus dispatching system of a small satellite data transmission subsystem. Background technique [0002] The satellite data transmission subsystem is a subsystem that transmits remote sensing and telemetry data to the ground in real time or with a delay after being stored on the satellite through a radio frequency link according to the set data format. There are many equipments in this subsystem. At present, the equipment mainly involved in small satellite data transmission includes data transmission control unit, compression encoder, data processor, modulation transmitter, solid-state memory, servo controller, antenna and other equipment. The design of the system adopts the architecture of the distributed control system. The digital transmission control unit is the control center and the nerve center of internal and extern...

AI Technical Summary

Problems solved by technology

In terms of telemetry, the data transmission control unit’s response to the upper-level bus is event-triggered, and the collection of lower-level telemetry is triggered by its own internal clock, including the internal clock trigger used by the lower-level equipment to collect its own telemetry. Due to clock asynchrony and drift, the acquisition time is inconsistent Variations in synchronization and acquisition cycles, asynchrony on the two-level bus increase the probability of telemetry loss and duplication

In addition, in terms of remote control, the digital transmission control unit receives the control commands sent by the star service subsystem, and then the digital transmission control unit forwards them to the lower-level bus equipment. There is no response and retransmission mechanism, and there is a risk of missing execution of key commands.

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