ORIGINAL ARTICLE Design of an adaptive-robust controller for a powder coating robot and its comparison with inverse dynamic approach S. M. Safavi & H. R. Hoshyarmanesh & S. S. Mirian & R. Khandan Received: 29 January 2008 / Accepted: 31 March 2009 / Published online: 6 May 2009 # Springer-Verlag London Limited 2009 Abstract In this research, the design and function of “DAP”, a 3-DOF ‘RRP’ (rotational/prismatic) dual-acting pick-and-place-painting robot, are first briefly presented and, along with its kinematic and dynamic analysis, is studied to eliminate the man presence in industrially polluted environment such as coating processes. The main function of this robot is coating epoxy powder on “Hawle” gate valves at temperatures up to 200°C. Then, the movement and control simulation trend for maneuvering in optimization path are described by non-linear inverse dynamic and adaptive-robust controllers as modern control methods regarding to angle and torque feedback systems in industrial robots. Comparison of these control approaches is considered in relation to uncertainties. The results obtained from this research could greatly satisfy the need for overcoming uncertainties in such combined industrial processes. Keywords Dual-acting robot . Coating process . Inverse dynamic and adaptive-robust controllers . Angle/torque feedback 1 Introduction Of the most applicable and the oldest industrial robots are the pick-and-place robots which have an important role in wide and different operations. The design and manufacture of the first sample of these robots date back to 1961 in an investment casting operation. The major reason for the application of such a mechanism at that time was the difficult environmental conditions for human activity due to poisonous gases resulting from the melt [1]. Today, the need for the implementation of operational cycles at high speeds and difficult handling has been one of the most important reasons for the use of industrial robots within the engineering framework of human factors. Although many years have passed since the manufacturing of such robots, extensive researches have been carried out throughout the world on the design, manufacture, trajectory path optimi- zation control, and dynamic load-carrying capacity as well. Fateh [2] has developed ideas on fuzzy impedance control for the performance of fast operations by robots on the basis of position feedback and velocity to overcome uncertainties. Huang et al. [3] have employed time minimum trajectory planning of a 2-DOF translational parallel robot for pick-and-place operations. Adaptive robust force/motion control strategies have been presented by Li, Ge, and Ming [4] for mobile manipulators under both holonomic and non-holonomic constraints in the presence of uncertainties such as mass variations and external disturbances. Also, Li et al. [5] have investigated robust adaptive force/motion tracking control for non- holonomic two-wheel mobile manipulators with unknown parameters and disturbances under uncertain holonomic constraints. Likewise, Li, Ge, and Wang [6] have presented robust control and robust adaptive control strategies Int J Adv Manuf Technol (2009) 45:1179–1186 DOI 10.1007/s00170-009-2043-6 S. M. Safavi : H. R. Hoshyarmanesh (*) : S. S. Mirian Mechanical Engineering Department, Isfahan University of Technology, Isfahan, Iran e-mail: hrh1983@me.iut.ac.ir S. M. Safavi e-mail: mosafavi@cc.iut.ac.ir R. Khandan The School of Design, Engineering and Computing, Bournemouth University, Dorset, UK