Journal of the Brazilian Society of Mechanical Sciences
versão impressa ISSN 0100-7386
FERREIRA, C. V. e ROMANO, V. F.. A Design Methodology for the Compensation of Positioning Deviation in Gantry Manipulators . J. Braz. Soc. Mech. Sci. [online]. 2002, vol.24, n.2, pp. 83-92. ISSN 0100-7386. http://dx.doi.org/10.1590/S0100-73862002000200001.
This work presents recent results concerning a design methodology used to estimate the positioning deviation for a gantry (Cartesian) manipulator, related mainly to structural elastic deformation of components during operational conditions. The case-study manipulator is classified as gantry type and its basic dimensions are 1,53m x 0,97m x 1,38m. The dimensions used for the calculation of effective workspace due to end-effector path displacement are: 1m x 0,5m x 0,5m. The manipulator is composed by four basic modules defined as module X, module Y, module Z and terminal arm, where is connected the end-effector. Each module controlled axis performs a linear-parabolic positioning movement. The planning path algorithm has the maximum velocity and the total distance as input parameters for a given task. The acceleration and deceleration times are the same. Denavit-Hartemberg parameterization method is used in the manipulator kinematics model. The gantry manipulator can be modeled as four rigid bodies with three degrees-of-freedom in translational movements, connected as an open kinematics chain. Dynamic analysis were performed considering inertial parameters specification such as component mass, inertia and center of gravity position of each module. These parameters are essential for a correct manipulator dynamic modelling, due to multiple possibilities of motion and manipulation of objects with different masses. The dynamic analysis consists of a mathematical modelling of the static and dynamic interactions among the modules. The computation of the structural deformations uses the finite element method (FEM).
Palavras-chave : Mechatronics design; robotics; Gantry manipulator; FEM modelling.