Basic robotic operations such as grasps of structure’s parts and their placement are mostly model based and do not take into account modelling error and geometry variations. As consequences, quality of the assembly cannot be trusted. In this paper, we propose to use 3D sensor and sensor-based control to improve the precision a positioning task. The interaction matrix is constructed upon assembly constraint definition. Those assembly constraints are taken into a task sequencing mechanism, with others robot-specific and environment tasks. The positioning operation is tested with Gazebo simulator and ROS environment and demonstrate the effectiveness of the approach.