Alessandro Formaglio Marco Fei Sara Mulatto Maurizio de Pascale Domenico Prattichizzo Autocalibrated Gravity Compensation for 3DoF Impedance Haptic Devices. 43-52 2008 EuroHaptics http://dx.doi.org/10.1007/978-3-540-69057-3_5 conf/haptics/2008e db/conf/haptics/eurohaptics2008.html#FormaglioFMPP08