Julien Gomand

Model-based control of a dual-drive H-type gantry stage on a decoupling base

Widely used for high-speed high-precision motion control in the electronics, nuclear and automotive industries, gantry stages are usually controlled using independent axis control. In order to avoid the effects of the mechanical coupling over synchronization and tracking errors, we propose a control on a modal reference frame. First, the system is modeled with respect to the center of mass of the moving beam and a modal transformation is applied to obtain the motion equations on a decoupling base. Next, a model-based control scheme is deduced with the minimization of synchronization and tracking errors as objectives. Finally, experimental results show that the proposed modal control scheme leads to an improved motion control of the point-tool in comparison with the present industrial control.

Physical dynamic modelling and systematic control structure design of a double linear drive moving gantry stage industrial robot

Industrial control of dual-drive moving gantry stage robots is usually achieved by two independent position controllers. This control structure does not take into account the mechanical coupling between the two actuators that leads to a reduction of the overall performances. In this paper, a physical dynamic lumped parameters model of an industrial robot based on structural, modal, and finite element method analysis is proposed, experimentally identified and validated. Then, using simple inversion rules of the causal ordering graph formalism, a control structure is deduced in a systematic way. The solution is finally simulated and shows that it is possible to obtain better performances than the industrial control.

Decoupling basis control of dual-drive gantry stages for path-tracking applications

Dual-drive gantry stages are used for high-speed high-precision motion control applications such as flat panel display manufacturing and inspection. Industrially, they are usually controlled using independent axis control without taking into consideration the effect of inter-axis mechanical coupling over positioning accuracy and precision. To improve this and minimize the effect of mechanical coupling over synchronization and tracking errors, we propose to model and control the dual-drive gantry stage on a decoupling basis. This approach allows representing the highly coupled Multiple Input Multiple Output (MIMO) system as a set of independent Single Input Single Output (SISO) systems. Based on this representation, a model-based feedback-feedforward control scheme is deduced. Experimental results show that the proposed decoupling basis control scheme leads to an improved motion control of the point-tool in comparison to the present industrial control.

Complementary use of BG and EMR formalisms for multiphysics systems analysis and control

In this paper, a complex multiphysics system is modeled using two different energy-based graphical techniques: Bond Graph and Energetic Macroscopic Representation. These formalisms can be used together to analyze, model and control a system. The BG is used to support physical, lumped-parameter modeling and analysis processes, and then EMR is used to facilitate definition of a control structure through inversion-based methodology. This complementarity between both of these tools is set out through a helicopter flight control subsystem.© 2012 ASME

Control of a Symmetrical Dual-drive Gantry System using Energetic Macroscopic Representation

Dual-drive gantry systems are commonly used in many industrial applications. However, as few papers are available in the literature, this kind of system is difficult to broach. Based on an energetic approach so-called Energetic Macroscopic Representation (EMR), this paper presents a graphical modelling based on lumped-parameters. The initial drive is decomposed into a set of decoupled fictitious systems using a mathematical transformation. Since the modelling respects the integral causality, inversion-based controls are thus deduced. More generally, this approach proposes a way to analyze and deduce models and controls of multi-drive mechatronic systems.

Modelling and Control of a Complex Multi-physic System: Case of Helicopter Flight Axis Control

A helicopter flight axis control, which is a complex multi-physic system, is modelled using an energetic based graphical tool. Element of the system are mainly composed of passive technologies and their number tends to increase years after years to improve the pilots comfort by adding new functions. Thanks to the recent march in electronic fields and in order to simplify flight structures, new active systems have come out in aeronautical systems, a specific sector which requires extreme rigors and approved technology. In this paper, a simplified helicopter flight axis control is modelled with the intention of controlling the helicopter stick force feedback. Using the Energetic Macroscopic Representation the detailed methodology presented in this paper is helpful to determine an adequate control for active systems with sampled signals.