1 1 (2) (3) d@* -MR, . R (4) 2 @q +ZVQ d i~ -R, . M RrM dt OL, d , L r OLsLr IQ --wr@d +-Abstract -The problem of induction motor state estimation and control without AC current measurements is considered. A state observer is designed by using a suitably reformulated output scheme and a decoupling controller with two independent current dr L, L, control loops is also presented. The proposed scheme is suitable equation of the motor dynamic model. A field oriented control d@d -MRr i , -!!qd -3 for series hybrid electric vehicles, so as confirmed by simulations IQ f W r @ d -L@q ' carried out with MatlablSimulink. dt L, L,

This paper considers the compensation for periodic torque disturbances, characteristic of electrical permanent magnet motors. These disturbances are sinusoidal with known but rapidly varying frequencies. The compensation is obtained as a two stage adaptive controller. The final compensator is obtained as a pure predictive feed forward compensation that includes an internal model of the disturbance. The disturbance's internal model identification is obtained applying a closed loop, adaptive feed forward control algorithm. The stability and robustness properties of the overall adaptive compensation technique are validated by experimental tests on industrial manipulators.

This paper aims at investigating vibrational behaviors of the industrial manipulator Racer 7-1.4, designed and manufactured by COMAU S.p.A., with the target of new trajectory planning strategies to improve productivity rate without any loss of positioning accuracy. Starting from the analysis of a 9DoF multi-body system with lumped parameter, the first natural frequency of the robot was calculated in seven reference positions. Then, static and dynamic simulations were run by applying saturated ramp input and large motions to analyze the vibrational behavior of the manipulator. This research underlines that the optimal way to design the robot move is to set its duration at twice a period of free oscillation according to the first vibrational mode. Due to strong analogy of dynamic response of both 1DoF and 9DoF robot models, the closed-form solution of the 1DoF undamped system—featured by natural frequency equal to the first frequency of the 9DoF system—may be successfully adopted by the real-time trajectory planning process to predict residual vibration at move end-condition. This strategy was confirmed by experimental tests, allowing either residual vibration decrease and execution time reduction as well.

H∞ control approaches are widely investigated in various application fields and in the robotics area, too, for their robustness properties. However, they are still rarely adopted in the industrial context for the control of robot manipulators, mainly due to the lack of predefined procedures to build weighting functions able to automatically guarantee the fulfillment of the control objectives. This paper reports the first results of an academic–industrial research activity aimed at investigating the adoption of an H∞ approach in the control software architecture of industrial manipulators, equipped with standard sensors on the motor side only. The design of the control system for a single-axis of an industrial manipulator is developed, showing that the construction of the weighting functions according to standard procedures can provide a satisfying behavior only on the motor side, leaving unacceptable oscillations of the link. A different procedure is then developed for the definition of the weighting functions with the specific aim of eliminating the possible vibrations of the mechanical structure. The proposed new form of such functions, including the main dynamic characteristics of the plant, ensures a robust, satisfying behavior on both the motor and the link side, as proven by simulation and experimental results.

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