@inproceedings{iecon94, author = {Rui Araújo and Urbano Nunes and A. T. de Almeida}, title = {Robot 3D Force-Based Surface-Tracking}, booktitle = {Proc. IEEE 20th International Conference on Industrial Electronics, Control and Instrumentation (IECON'94)}, pages = {788-793}, address = {Bologna, Italy}, month = {September 5-9}, year = {1994}, publisher = {IEEE}, doi = {10.1109/IECON.1994.397886} }