01571nas a2200265 4500008004100000245007700041210006900118300000900187520075100196653002100947653004400968653001301012100001501025700001401040700001701054700001701071700001701088700001501105700001801120700001201138700001501150700001101165700001601176856011301192 2008 eng d00aPhysical Human-Robot Interaction: Dependability, Safety, and Performance0 aPhysical HumanRobot Interaction Dependability Safety and Perform a9-143 a

In this paper we discuss the problem of achieving good performance in accuracy and promptness by a robot manipulator under the condition that safety is guaranteed throughout task execution. Intuitively, while a rigid and powerful structure of the arm would favor its performance, lightweight compliant structures are more suitable for safe operation. The quantitative analysis of the resulting design trade-off between safety and performance has a strong impact on how robot mechanisms and controllers should be designed for human-interactive applications. We discuss few different possible concepts for safely actuating joints, and focus on aspects related to the implementation of the mechanics and control of this new class of robots.

10aEmbedded Control10aPhysical Human-Robot Interaction (pHRI)10aRobotics1 aBicchi, A.1 aBavaro, M1 aBoccadamo, G1 aCarli, De, D1 aFilippini, R1 aGrioli, G.1 aPiccigallo, M1 aRosi, A1 aSchiavi, R1 aSen, S1 aTonietti, G uhttp://95.110.227.16/publications/physical-human-robot-interaction-dependability-safety-and-performance.html01480nas a2200193 4500008004100000245006500041210006400106260003300170300001400203490000700217520082500224653004401049653001301093100001601106700001501122700001501137700003501152856009901187 2006 eng d00aOptimal Mechanical/Control Design for Safe and Fast Robotics0 aOptimal MechanicalControl Design for Safe and Fast Robotics bSpringer Berlin / Heidelberg a311 - 3200 v213 a

The problem to ensure safety of performant robot arms during task execution was previously investigated by authors. The problem can be approached by studying an optimal control policy, the "Safe Brachistocrone", whose solutions are joint impedance trajectories coordinated with desired joint velocities. Transmission stiffness is chosen so as to achieve minimum-time task execution for the robot, while guaranteeing an intrinsic safety level in case of an unexpected collision between a link of the arm and a human operator. In this paper we extend this approach to more general classes of robot actuation systems, whereby other impedance parameters beside stiffness (such as e.g. joint damping and/or plasticity) can vary. We report on a rather extensive experimental campaign validating the proposed approach.

10aPhysical Human-Robot Interaction (pHRI)10aRobotics1 aTonietti, G1 aSchiavi, R1 aBicchi, A.1 aMarcelo H. Ang, Oussama Khatib uhttp://95.110.227.16/publications/optimal-mechanicalcontrol-design-safe-and-fast-robotics.html01811nas a2200217 4500008004100000245007700041210006900118260003300187300001400220490000700234520109300241653004401334653001301378100001701391700001501408700001101423700001601434700001501450700001901465856010901484 2006 eng d00aOptimization and Fail-Safety Analysis of Antagonistic Actuation for pHRI0 aOptimization and FailSafety Analysis of Antagonistic Actuation f bSpringer Berlin / Heidelberg a109 - 1180 v223 a

In this paper we consider some questions in the design of actuators for physical Human-Robot Interaction (pHRI) under strict safety requirements in all circumstances, including unexpected impacts and HW/SW failures. We present the design and optimization of agonistic-antagonistic actuation systems realizing the concept of variable impedance actuation (VIA). With respect to previous results in the literature, in this paper we consider a realistic physical model of antagonistic systems, and include the analysis of the effects of cross-coupling between actuators. We show that antagonistic systems compare well with other possible approaches in terms of the achievable performance while guaranteeing limited risks of impacts. Antagonistic actuation systems however are more complex in both hardware and software than other schemes. Issues are therefore raised, as to fault tolerance and fail safety of different actuation schemes. In this paper, we analyze these issues and show that the antagonistic implementation of the VIA concept fares very well under these regards also.

10aPhysical Human-Robot Interaction (pHRI)10aRobotics1 aBoccadamo, G1 aSchiavi, R1 aSen, S1 aTonietti, G1 aBicchi, A.1 aChristensen, H uhttp://95.110.227.16/publications/optimization-and-fail-safety-analysis-antagonistic-actuation-phri.html01523nas a2200169 4500008004100000245008100041210006900122260002600191300001400217520089600231653004401127653001501171100001501186700002101201700001601222856011501238 2001 eng d00aCompliant design for intrinsic safety: general issues and preliminary design0 aCompliant design for intrinsic safety general issues and prelimi aMaui, HawaiicOctober a1864-18693 a

In this paper, we describe some initial results of a project aiming at development of a programmable-compliance, inherently safe robot arm for applications in anthropic environmnets. In order to obtain safety in spite of worst-case situations (such as unexpected delays in teleoperation, or even controller failure), we will consider achieving compliance by mechanical rather than by control design. We first describe some of the control problems that the presence of large, possibly unknown mechanical compliance typically introduces, and present a result that shows the possibility to cope with these uncertainties in an adaptive way. In the second part of the paper we describe the initial development of a new prototype arm under construction in our laboratory. The arm is designed to achieve arbitrary position tracking in 3D with controlled effective compliance at the joints.

10aPhysical Human-Robot Interaction (pHRI)10aRobot Arms1 aBicchi, A.1 aRizzini, Lodi, S1 aTonietti, G uhttp://95.110.227.16/publications/compliant-design-intrinsic-safety-general-issues-and-preliminary-design.html01451nas a2200181 4500008004100000245005200041210005200093300001200145520088700157653004401044653001501088100001501103700002101118700001601139700001401155700001301169856008701182 2001 eng d00aCompliant robot arm design for intrinsic safety0 aCompliant robot arm design for intrinsic safety a100-1063 aIn this paper, we describe some initial results of a project aiming at development of a programmable-compliance, inherently safe robot arm for applications in anthropic environmnets. In order to obtain safety in spite of worst-case situations (such as unexpected delays in teleoperation, or even controller failure), we will consider achieving compliance by mechanical rather than by control design. We first describe some of the control problems that the presence of large, possibly unknown mechanical compliance typically introduces, and present a result that shows the possibility to cope with these uncertainties in an adaptive way. In the second part of the paper we describe the initial development of a new prototype arm under construction in our laboratory. The arm is designed to achieve arbitrary position tracking in 3D with controlled effective compliance at the joints.10aPhysical Human-Robot Interaction (pHRI)10aRobot Arms1 aBicchi, A.1 aRizzini, Lodi, S1 aTonietti, G1 aGiralt, G1 aCorke, P uhttp://95.110.227.16/publications/compliant-robot-arm-design-intrinsic-safety.html