One of the main tasks in robotics is to precisely connect the robot's coordinate system with the world's coordinate system. For parallel mechanisms, this is a challenging task due to the direct kinematics problem, which is usually solved by using iterative algorithms to search for the mobile platform's position and orientation or by adding auxiliary sensors. In this paper, a sensor concept for solving the direct kinematics problem of the Stewart-Gough platform is presented where only three inertial measurement units are used with the aim to renounce length sensors as well as initial and, in some cases, external pose measurements.