THE ARGO EXPERIMENT POINTING SYSTEM AS AN EXAMPLE FOR OTHER SINGLE-AXIS PLATFORM POINTING SYSTEMS

This paper introduces a design of a stratospheric platform pointing system taking into account, as an example, the design of an infrared experiment named ARGO. It shows the design philosophy of both mechanical and electrical parts as well as some software solutions to interface the position sensor (magnetometer) and motor power amplifiers for these gondola azimuth movements. This pointing system controls a single-axis platform (the infrared telescope, in this case, does not require an elevation motion) and may either show the way for other similar stratospheric experiments or be the first step of a higher axis stabilization. It is a two DC torque motor design housed, with a tachometer, in a particular and compact solution named 'pivot'. One motor is devoted to avoiding any disturbance, during stratospheric flight, coming from random rotation of the cruise balloon and the other for any pointing motion needs. The control hardware, fully digital and built around a cpu card, gives this system a high degree of versatility.