• optimal control
• performance
• pHRI
• safety

This thesis deals with some aspects of safety and performance for service robots, focusing on advantages offered by the use of Variable Impedance Actuators (VIA) in improving performance under safety constraints.
The Maximum Impact Force (MIF) is considered as a possible safety index to evaluate
the risk of physical human-robot interaction (pHRI) comparing it to the Head Injury Criterion (HIC), a safety measure used for automotive crash-tests.
Approximate analytical expressions of MIF have been proposed and numerically validated.
The concept of performance at the actuator level has been investigated through a comparative analysis of different VIA prototypes in order to define a global performance index.
The trade-off between Performance and Safety has been approached with the Optimal Control Theory,
investigating the uniqueness of the optimal solution and confirming performance improvement by using VIA devices.