Method for determining the state variables of a moving rigid body in space

A method for determining the state variables of a moving rigid body, such as relative position and attitude as well as translational and rotational speeds, in particular for a movement of approach to another body employing measured data provided by an active sensor, the measured data being derived from at least three rectroreflectors whose configuration on the other body is known and is assigned in a defined fashion to a body-specific coordinate system of the other body, comprising the steps of:

• determining the state variables of said moving body with the aid of a state observer which processes the measured data of scannings of individual rectroreflectors in space by an internal memory model to produce a desired output of the state variables of said moving body;
• in which case,
• starting from set initial values and known system parameters implemented in operators, a current state vector of said moving body is calculated as an estimate;
• using a correction determined by linkage with the measured data to adapt said estimate with each measuring cycle to the actual attitude characteristic and movement characteristic of the body, such that after a specific number of measuring and calculating cycles the estimated values calculated in the state observer track the current movement data of said moving body in space to a very good approximation;
• and
• in using the calculated estimated values as state variables of said moving body.