Absolute position data (605) of a machine are determined for respective multiple times (t.1, t.3, t.5, t.8, t.11), and odometry position data of the machine are alsodetermined. A pose graph (661) is generated, wherein edges (672) of the pose graph (661) correspond to the odometry position data, and nodes (671) of the pose graph (661) correspond to the absolute position data (605). The pose graph (661) is optimised to obtain an estimated position. Optionally, the odometry can also be estimated. A driver assistance functionality of the machine, for example a motor vehicle, can be controlled optionally on the basis of the estimated position. For example, the driver assistance functionality can relate to autonomous driving.