Testing the entire attitude control system of a microsatellite is a complex step in the verification process. Software-in-the-loop simulations (SILS) and hardware-in-the-loop simulations (HILS) are established test methods for this.

A end-to-end testing has many advantages. ASTROFEIN, for example, has developed experience from various satellite projects, ASTROFEIN has designed and realised a new type of ACS test stand (attitude control test stand) for small and microsatellite buses.

ACS_Test Bed

Features of the ACS Test Bed

  • Mounting platform on an air bearing table allowing free 360° rotation around the vertical axis and 20° – 30° rotation around the horizontal axis
  • High-precision in-orbit magnetic field simulation
  • Electronic centre of gravity calibration (CoG)
  • Adjustable and movable sun simulation
  • WLAN command interface
  • Safety mechanisms for smooth operation and installation
  • Power supply for the test object

Complex simulations possible

With this test bench, a complete end-to-end verification of ACS systems for mini and micro satellites with high target accuracy, including long-term tests, is possible. This test bench is an ideal extension of software-in-the-loop and hardware-in-the-loop testing, taking into account the specific design and testing requirements.

ACS Detail
Air bearing table

Air-bearing table and platform

By using a high-precision air bearing and non-contact calibration of the air gap, the disturbance forces along all three axes can be kept low, comparable to the in-orbit dis-turbance moments of lower Earth orbits. In addition, the air bearing table is equipped with a safety mechanism that serves to protect the air bearing.

The platform consists of a mounting plate with a mechanical interface for the DUT, a CoG calibration system, the power supply and various equipment.

GNSS and star image simulation

The GNSS simulation consists of a hardware and software component as well as
the remote connection to the control software of the test bed. The GNSS simulator can support all current GNSS signals, including GPS, GLONASS, Galileo, Bei-Dou-2, WAAS, EGNOS, MSAS, GAGAN, SDCM, QZSS and IRNSS.

This extension to the ACS testbed enables the simulation of sensor inputs
of a star tracker and the integration of a star tracker into the ACS hardware-in-the-loop test environment. The Star Simulator can deliver signals and provide up to four optical heads simultaneously for this purpose. The system simulates stars, planets, sun, scattered light and protons.

ACS_Test Bed black
ACS Detail

Reference system

The external reference system, based on 3D motion tracking, can be used to measure the
position of the platform and the test specimen independently of the simulation. The position of the platform is visualised in the test stand control software and generates inputs for the optional star simulation.
optional star simulation. Additionally, the position can be logged together with the simulation data.