Analysis of the delta robot dynamic errors caused by the components elastic strain

Delta robot is one of the most successful and commercialized types of the parallel robots, they are widely used in manufacture and other various areas of the human activity. Their advantages over the other types of robots include design simplicity, high operation speed and strength reliability. At the same time, there appears a trend to lighten the design to increase the operation speed. However, this leads to an increase in structure deformability and undesirable oscillations, which affects the delta robot positioning accuracy and significantly limits its use in high-speed and high-precision operations. The paper considers positioning errors in the delta robot executive tools caused by the elastic strain of its components during the high-speed operations of the object capture, placement and displacement. Based on a dynamic model of the parallel robot with rigid-elastic connections, it proposes a computation method making it possible to optimize the design and significantly reduce the undesirable effects. The proposed computation method is based on the consistent introduction of the commercial (Hypermesh, Adams) and proprietary software programs created in the MATLAB environment. The delta robot trajectory is planned using the modified curved trapezoidal acceleration, which makes it possible to obtain rational laws for changing the control parameters of the three drive levers during its motion. The found solutions to the inverse kinematics problem were used to simulate the robot dynamics and calculate the dynamic errors caused by elastic strain of its components. Computation results are presented making it possible to minimize the influence of the delta robot elastic deformation on its positioning accuracy and increase its productivity in the technological operations.
EDN: UNXJRI, https://elibrary/unxjri

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