Evaluation of head-collision safety of a 7-DOF manipulator according to posture variation
- 221 Downloads
As the need for the improvement of the productivity in the manufacturing process grows, industrial robots are brought out of the safety fences and used in the direct collaborative operation with human workers. Consequently, the intended and/or unintended contact between the human and the robot in the collaborative operation is no longer an extraordinary event and is a mundane possibility. The level of the risk of the collision depends on various quantities associated with the collision, for example, inertia, velocity, stiffness, and so on. MSI (manipulator safety index) which is based on HIC (head injury criteria) conventionally used in the automotive industry is one of the practically available measures to estimate the risk of the collision between the human and the manipulator. In this paper MSI is applied to evaluate the collision safety of a 7-DOF articulated human-arm-like manipulator. The risk of the collision could be reduced by choosing different postures without deviating from the given end-effector trajectory using the redundant degree of freedom in the 7-DOF manipulator. The paper shows how the redundant degree of the freedom is utilized to design safer trajectories and/or safer manipulator configurations among many available. A parametric analysis and simulation results for a given trajectory illustrate the usefulness of the concept of the trajectory design for alleviating the risk of the manipulator operation in the human–robot coexisting workspace.
KeywordsManipulator safety Collision safety 7-DOF manipulator Collaborative operation
This work was supported by the project (project number: 10051117) funded by the Ministry of Trade, Industry & Energy (MOTIE), Korea.
- 2.Zinn, M.R.: A new actuation approach for human-friendly robotic manipulator. Stanford University, 2005 Google Scholar
- 4.Versace, J.: A review of the severity index. In: Proc. 15th Stapp Conf., SAE 710881, pp. 771–796 (1971) Google Scholar
- 5.Craig, J.J.: Introduction to Robotics Mechanic and Control, 3rd edn. Prentice Hall, New York (2004) Google Scholar
- 6.Kim, K.H., Park, I.J., Rhim, S.: Evaluation of safety index of 7-DOF manipulator considering collision safety. In: Proceedings of the 3rd IMSD and the 7th ACMD Conference, Busan, Korea, pp. 433–442 (2014) Google Scholar
- 7.Khatib, O.: Inertial properties in robotics manipulation: an object-level framework. Intl. Journal of Robotics Research 14(1), 19–36 Google Scholar
- 9.Haddadin, S.: Human injury issues in robotics. Robotics and Mechatronics Center, German Aerospace Center, 2013 Google Scholar
- 10.Moss, W.C., King, M.J., Blackman, E.G.: Skull flexure form blast waves: a mechanism for brain injury with implications for helmet design. Phys. Rev. Lett. 112, 068103 (2009) Google Scholar