Abstract: The walking robots motion control is included in the category of systems with a high degree of automation. The mechanical system must be equipped with a large number of degrees of mobility (DOF), in order to form complex synergies and to achieve coordinated movement of the legs. The action of such disturbances like an additional load, changes in weight, position of center of gravity and the robot platform inertial moments and may be a cause of significant deviations from the robot prescribed motion. A number of compliant control techniques are known for obtaining high performance in robot trajectory control, some of which include a dynamic model in the control loop: solved acceleration loop (Luh, Walker and Paul), operational space method (Khatib), impedance control (Hogan, Kazerooni, Sheridan) and other which do not include dynamic models: hybrid control (Railbert si Craig) and rigidity control (Salisbury). In order to increase mobility and stability in real conditions and to obtain superior results relating to the possibility of moving walking robots on terrains with close configuration to real situations such as slope walking, overtaking or avoiding obstacles, the paper presents research regarding the integration of compliant control and fuzzy control into the hybrid position force control system architecture for hexapod walking robots. Stability analyses and experimental implementations have shown not only that using dynamic models leads to a more precise control, but also that using an inadequate dynamic model can sometimes lead to unstable force control. A dynamic position-force control system is presented by integrating the multi-stage fuzzy method with solved acceleration in position-force control and dynamic control loops through the ZMP method. It is also noted that in addition to hybrid position-force control, three other main tasks are added, resulting from the analysis of the robot's walking cycle, conforming to movement characteristics: real time balance control, walking scheme control and predictable control of the walking robot movement. The first main task, balance control, leads to a control model that periodically modifies the walking scheme, depending on the sensory information received from the robot transducers. Real time balance control contains 4 types of reactive loops: damping control, ZMP compensation control, walk timing control and walk orientation control. The second main task, walking scheme control, represents a real time control of the robot equilibrium using the reactions of inertial sensors. The walking control scheme can be changed periodically in accordance with the information received from the inertial sensors during the walking cycle, by processing them into two real time loops: platform swing amplitude control and platform rotation/advance control. The third main task, predictable movement control, represents the control of predictable movement based on a fast decision from previous experimental data. The results obtained shows that this allows the robot to adapt to rough terrain through a real time control with increased stability during walking. In the end, a multi-microprocessor architecture is designed with multi-tasking control that allows a fast feedback loop for real time robot control, improving stability and flexibility performance.

Brief Biography of the Speaker:
Luige Vladareanu received his M.Sc. degree in electronics from the Polytechnic Institute Bucharest, in 1977. From 1984, scientific researcher of the Institute of Physics and Material Technology, from 1990, team leader of data acquisition systems and real time control systems of the Institute of Solid Mechanics, from 1991, President General Manager of Engineering and Technology Industrial VTC Company. In 1998 he received Ph.D. degree in electronics field from the Institute of Solid Mechanics of Romanian Academy. From 2003, Ministry of Education and Research, executive Department for Financing Superior Education and of Scientific University Research - High Level Expert Consulting for MEC/CNCSIS project, from 2003-2005, member of Engineering Science Committee of Romanian National Research Council, from 2005, Scientific Researcher Gr.I (Professor) of Romanian Academy, from 2009 Head of Mechatronics Department of Institute of Solid Mechanics, Romanian Academy. His scientific work is focused on real time control in solid mechanics applied in robot trajectory control, hybrid position – force control, multi-microprocessor systems for robot control, acquisition and processing of experimental physical data, experimental methods and signal processing, nano-micro manipulators, semi-active control of mechanical system vibrations, semi-active control of magnetorheological dissipaters systems, complex industrial automations with programmable logical controllers in distributed and decentralized structure. He has published 4 books, over 20 book chapters, 11 edited books, over 200 papers in journals, proceedings and conferences in the areas. Director and coordinator of 7 grants of national research – development programs in the last 5 years, 15 invention patents, developing 17 advanced work methods resulting from applicative research activities and more then 60 research projects. In 1985 the Central Institute of Physics Bucharest awarded his research team a price for the first Romanian industrial painting robot. He is the winner of the two Prize and Gold of Excellence in Research 2000, SIR 2000, of the Romanian Government and the Agency for Science, Technology and Innovation. 9 International Invention and Innovation Competition Awards and Gold of World's Exhibition of Inventions, Geneva 2007 - 2009, and other 9 International Invention Awards and Gold of the Brussels, Zagreb, Bucharest International Exhibition. He received “Traian Vuia” (2006) award of the Romanian Academy, Romania's highest scientific research forum, for a group of scientific papers published in the real time control in the solid mechanics. He is team leader of two ANCS (Scientific Research National Agency) funded research projects: “Fundamental and Applied Researches for Position Control of HFPC MERO Walking Robots” from CNCSIS-Exploratory Researches Program and “Complex Modular Automation Systems for Technological Flux Control AUTMPG” from AMCSIT-Innovation Program. He is a member of the International Institute of Acoustics and Vibration (IIAV), Auburn University, USA (2006), ABI/s Research Board of Advisors, American Biographical Institute (2006), World Scientific and Engineering Academy Society, WSEAS (2005), International Association for Modelling and Simulation Techniques in Enterprises-AMSE, France (2004), National Research Council from Romania(2003-2005), etc. He is a PhD advisor in the field of mechanical engineering at the Romanian Academy. He was an organizer of several international conferences such as the General Chair of four WSEAS International Conferences (http://www.wseas.org/conferences/2008/romania/amta/index.html), chaired Plenary Lectures to Houston 2009, Harvard, Boston 2010 and Penang, Malaysia 2010 to the WSEAS International Conferences, is team leader of WSEAS scientific research project: Mechanics & Robotics Systems and is serving on various other conferences and academic societies.