Overall strategy
The strategy of SAPHARI is to address safe physical human robot interaction following both a bottom-up and a top-down approach. As a major difference to previous projects, technology push will provide essential contributions to all areas of robot manipulation that involve the presence of and physical interaction with humans. At the same time, demand pull will increase the pertinence and impact of the results by orienting work towards real use cases from 3 different branches: manufacturing, aeronautics and medical care. The integrated approach covers five conceptual levels corresponding to major research and development areas in robotics. These levels are summarized in the Figure below, together with the related work packages (WPs).
The first level - Specification and Verification - will provide an analysis of the current state and the demands of the market regarding new applications involving human-robot interaction both from the perspective of a robot manufacturer and of an industrial user. This will lead to requirements and specifications for pHRI in a goal oriented approach. Another fundamental contribution on this level is to provide tools and measures for evaluating safety of humans in pHRI both from biomechanics perspective as well as from the risk analysis point of view. The use case studies and safety analysis will provide requirements and measures for result verification to all other work packages. |
The second level - Design - is dedicated entirely to human-centred hardware development. The use cases and test beds within the project will be based on two types of robots. For torque controlled robots provided by KUKA or similar advanced robots designed for pHRI, constituting a mature technology, hardware development will focus on safe tools and tool changers, safety design of the entire workplace and intuitive man-machine interfaces. The main hardware development effort will be devoted to complex manipulator systems based on variable impedance actuators (VIA). Already, first prototypes are available at the partner sites based on this new technology. We aim to further develop this actuator concept and realise complex manipulation systems as required by the pHRI applications addressed in the project. Most methods developed in the project on the higher levels will be implemented and evaluated on torque controlled systems first and then adapted to VIA systems as soon as these will become available. |
The third level - Behaviour - is expected to provide the basic, real-time tools for pHRI regarding perception and control. Real-time workspace supervision and human detection is a crucial pre-requisite for any kind of pHRI. Moreover, as explained in the objectives description, the control of the robots needs to provide a very rich repertoire of methods for interaction, collision detection, online reaction to obstacles, and unexpected motions of the human. As a logical consequence the reactive planning and control level need to be tightly coupled and share the task of safe online reaction generation for kinematically and dynamically highly complex robotic systems. Control of the VIA systems is another major challenge at this level. Known robotics control methods need to be expanded to full VIA manipulators, new specific control issues of these systems need to be addressed, and their interrelation with reactive planning to be treated. |
The fourth level - Decision and Action - will intensively use the outcome of the previous level and will provide interpretation and leaning techniques for understanding human motions, gestures, and intentions during an interactive task with the robot. Online motion and task planning for pHRI with adequate reaction time for systems having 50 degrees of freedom or more is not feasible following current approaches. The new strategy taken in this project is to provide an intermediate level of reactive action generation, which links the instantaneous, local, control methods and the global planning providing an online reactivity level for medium time and space ranges. This will support the planning tasks, enabling them to plan motions and action plans for such complex applications as our use cases in adequate time and at the same time leave the immediate sensor-based safety oriented decisions to the faster control loops. |
The fifth level - Application - will implement three uses cases. The first two are industrial scenarios and focus on the implementation and validation of co-worker concepts while the third covers professional services in a hospital environment. The ambitious goals of the use cases can only be achieved by incorporating pHRI features. One industrial application will be realised at the robot manufacturer KUKA, addressing joint manufacturing of robots by humans and other robots. The second use case will be provided by EADS, an industrial end-user from aerospace industry, aiming at demonstrating the feasibility and maturity of the concepts for the market. The third use case is more research-oriented, aiming at the evaluation of prototypical, higher risk results in a challenging application. It can also be viewed as an opportunity for integrating and testing academic results before transferring them to industrial setups. |