Luca Muratore

WALK‐MAN: A High‐Performance Humanoid Platform for Realistic Environments

In this work, we present WALK-MAN, a humanoid platform that has been developed to operate in realistic unstructured environment, and demonstrate new skills including powerful manipulation, robust balanced locomotion, high-strength capabilities, and physical sturdiness. To enable these capabilities, WALK-MAN design and actuation are based on the most recent advancements of series elastic actuator drives with unique performance features that differentiate the robot from previous state-of-the-art compliant actuated robots. Physical interaction performance is benefited by both active and passive adaptation, thanks to WALK-MAN actuation that combines customized high-performance modules with tuned torque/velocity curves and transmission elasticity for high-speed adaptation response and motion reactions to disturbances. WALK-MAN design also includes innovative design optimization features that consider the selection of kinematic structure and the placement of the actuators with the body structure to maximize the robot performance. Physical robustness is ensured with the integration of elastic transmission, proprioceptive sensing, and control. The WALK-MAN hardware was designed and built in 11 months, and the prototype of the robot was ready four months before DARPA Robotics Challenge (DRC) Finals. The motion generation of WALK-MAN is based on the unified motion-generation framework of whole-body locomotion and manipulation (termed loco-manipulation). WALK-MAN is able to execute simple loco-manipulation behaviors synthesized by combining different primitives defining the behavior of the center of gravity, the motion of the hands, legs, and head, the body attitude and posture, and the constrained body parts such as joint limits and contacts. The motion-generation framework including the specific motion modules and software architecture is discussed in detail. A rich perception system allows the robot to perceive and generate 3D representations of the environment as well as detect contacts and sense physical interaction force and moments. The operator station that pilots use to control the robot provides a rich pilot interface with different control modes and a number of teleoperated or semiautonomous command features. The capability of the robot and the performance of the individual motion control and perception modules were validated during the DRC in which the robot was able to demonstrate exceptional physical resilience and execute some of the tasks during the competition.

XBotCore: A Real-Time Cross-Robot Software Platform

In this work we introduce XBotCore (Cross-Bot-Core), a light-weight, Real-Time (RT) software platform for EtherCAT-based robots. XBotCore is open-source and is designed to be both an RT robot control framework and a software middleware. It satisfies hard RT requirements, while ensuring 1 kHz control loop even in complex Multi-Degree-Of-Freedom systems. It provides a simple and easy-to-use middleware Application Programming Interface (API), for both RT and non-RT control frameworks. This API is completely flexible with respect to the framework a user wants to utilize. Moreover it is possible to reuse the code written using XBotCore API with different robots (cross-robot feature). In this paper, the XBotCore design and architecture will be described and experimental results on the humanoid robot WALK-MAN [17], developed at the Istituto Italiano di Tecnologia (IIT), will be presented.

The Walk-Man Robot Software Architecture

A software and control architecture for a humanoid robot is a complex and large project, that involves a team of developers/researchers to be coordinated and requires many hard design choices. If such project has to be done in a very limited time, i.e. less than one year, more constraints are added and concepts such as modular design, code reusability and API definition need to be used as much as possible. In this work we describe the software architecture developed for Walk-Man, a robot participant at the Darpa Robotics Challenge. The challenge required the robot to execute many different tasks such as walking, driving a car, and manipulating objects.These tasks need to be solved by robotics specialists in their corresponding research field, such as humanoid walking, motion planning or object manipulation. The proposed architecture was developed in 10 months, provided boilerplate code for most of the functionalities required to control a humanoid robot and allowed robotics researchers to produce their control modules for DRC tasks in a short time. Additional capabilities of the architecture include firmware and hardware management, mixing of different middlewares, unreliable network management,operator control station GUI. All the source code related to the architecture and some control modules have been released as open source projects.

An affordance-based pilot interface for high-level control of humanoid robots in supervised autonomy

In this work we present the concept of a pilot interface to control a humanoid robot on an abstract level in unknown environments. The environment is perceived with a stereo camera system and then simplified into a set of environmental primitives. Based on these primitives the interface proposes affordances to the pilot. Affordances are represented as certainty functions over the space of end-effector poses. The pilot operates the robot by selecting among proposed affordances and related action primitives, i.e. Object-Action Complexes (OACs). Before initiating execution, the pilot can review and revise the parameterization of the scheduled action primitive in a 3D reconstruction of the environment. The pilot interface proposed in this work has been implemented and evaluated on the humanoid robot WALK-MAN. With this work we also demonstrate the transferability of the perceptual concept, as our previous experiments have been performed using the humanoid robot ARMAR-III.

WALK-MAN Humanoid Platform

In this chapter we present WALK-MAN, a humanoid platform that has been developed to operate in realistic unstructured environments and demonstrate new skills including powerful manipulation, robust balanced locomotion, high strength capabilities and physical sturdiness. To enable these capabilities, WALK-MAN design and actuation are based on the most recent advancements of Series Elastic Actuation (SEA) drives with unique performance features that differentiate the robot from previous state-of-the-art compliant actuated robots. Physical interaction performance benefits from both active and passive adaptation thanks to WALK-MAN actuation, which combines customized high performance modules with tuned torque/velocity curves and transmission elasticity for high speed adaptation response and motion reactions to disturbances. The WALK-MAN design also includes innovative design optimization features that consider the selection of kinematic structure and the placement of the actuators with respect to the body structure to maximize the robot performance. Physical robustness is ensured with the integration of elastic transmission, proprioceptive sensing and control. WALK-MAN hardware was designed and built in 11 months, and the prototype of the robot was ready 4 months before the DARPA Robotics Challenge (DRC) Finals. The motion generation of WALK-MAN is based on the unified motion generation framework of whole-body locomotion and manipulation (termed loco-manipulation). WALK-MAN is able to execute simple loco-manipulation behaviours synthesized by combining different primitives defining the behaviour of the center of gravity, of the hands, legs and head, the body attitude and posture, and the constrained body parts such as joint limits and contacts. The motion generation framework including the specific motion modules and software architecture are discussed in detail. A rich perception system allows the robot to perceive and generate 3D representations of the environment as well as detect contacts and sense physical interaction force and moments. The operator station that pilots use to control the robot provides a rich pilot interface with different control modes and a number of tele-operated or semi-autonomous command features. The capability of the robot and the performance of the individual motion control and perception modules were validated during the DARPA Robotics Challenge in which the robot was able to demonstrate exceptional physical resilience and execute some of the tasks during the competition.

Humanoids at Work: The WALK-MAN Robot in a Postearthquake Scenario

Nowadays human intervention is the only effective course of action after a natural or artificial disaster. This is true both for the relief operations where search–and–rescue of survivors is the priority, and for subsequent activities such as the ones devoted to building assessment. In these contexts the use of robotic systems would be beneficial to drastically reduce operators’ risk exposure. The readiness level of the robots still prevents their effective exploitation in relief operations, that are highly critical and characterized by severe time constraints. On the contrary current robotic technologies can be profitably applied in procedures like building assessment after an earthquake. To date, these operations are carried out by engineers and architects who inspect numerous buildings over a large territory, with a high cost in terms of time and assets, and with a high risk due to aftershocks. The main idea is to have the robot acting as an alter-ego of the human operator, who, thanks to a virtual reality device and a body tracking system based on inertial sensors, teleoperates the robot. The goal of this paper is to exploit the perception and manipulation capabilities of the WALK-MAN robot for building assessment in areas affected by earthquakes. The presented work illustrates the hardware and software characteristics of the developed robotic platform, and results obtained with field testing in the real earthquake scenario of Amatrice, Italy. Finally considerations on the experience and feedback provided by civil engineers and architects engaged in the activities are reported and discussed.

Corrigendum: The Walk-Man Robot Software Architecture

Alberto Cardellino, Alessio Rocchi, Enrico Migo Hoffman, Corrado Pavan and Dimitrios Kanoulas were not included as authors in the published article. Here is the updated Author contributions: MF, LM, AS, AR, EMH, AC, DK, CP, and LN worked on the design of the global architecture and on the network. LM, MF, AR, EMH, AC, and NT designed and developed GYM and the HAL. AS and CP developed the operator control station GUI and many control modules. LP and NT coordinated and advised other authors on all the aspects of this work. In the original article, there was an error. Corrado Pavan and Alberto Cardellino were included in the Acknowledgments section. A correction has been made to Acknowledgments: This work is supported by the European commission project Walk-Man EU FP7-ICT no. 611832. The authors would like to thank Stefano Cordasco and Alessio Margan for their work on the design and implementation of electronic boards and firmware. The authors apologize for these errors and state that these do not change the scientific conclusions of the article in any way. The original article has been updated.