Haptics: Perception, Devices and Scenarios (EuroHaptics 2008) pages:73-82
6th International Conference on Haptics: Perception, devices and scenarios edition:6 location:Madrid, Spain date:11-13 juni 2008
At present, surgical master-slave systems lack any kind of force feedback. Typically, controllers giving good stiffness transparency for soft environments cannot guarantee stability during hard contact. This paper presents a pragmatic method to avoid instability of a asterslave system during hard contacts, which does not affect the stiffness reflection for soft environments. The time derivative of the interaction force with the environment is used to detect a hard contact. Upon detection of a hard contact the force feedback is switched off and a virtual wall is activated at the master side in order to guarantee the perception of hard contact by the operator. The experiments demonstrate good stiffness transparency for soft environments, while the system remains stable for both soft and hard environments.