Design, development and control of a new generation high performance linear actuator for parallel robots and other applications

摘要

The main focus of this research is to design and develop a high performance linearudactuator based on a four bar mechanism. The present work includes the detailed analysisud(kinematics and dynamics), design, implementation and experimental validation of theudnewly designed actuator. High performance is characterized by the acceleration of theudactuator end effector. The principle of the newly designed actuator is to network the fourudbar rhombus configuration (where some bars are extended to form an X shape) to attainudhigh acceleration.udFirstly, a detailed kinematic analysis of the actuator is presented and kinematicudperformance is evaluated through MATLAB simulations. A dynamic equation of theudactuator is achieved by using the Lagrangian dynamic formulation. A SIMULINK controludmodel of the actuator is developed using the dynamic equation. In addition, Bond Graphudmethodology is presented for the dynamic simulation. The Bond Graph model comprisesudindividual component modeling of the actuator along with control. Required torque wasudsimulated using the Bond Graph model. Results indicate that, high acceleration (aroundud20g) can be achieved with modest (3 N-m or less) torque input.udA practical prototype of the actuator is designed using SOLIDWORKS and thenudproduced to verify the proof of concept. The design goal was to achieve the peak acceleration of more than 10g at the middleudpoint of the travel length, when the end effector travels the stroke length (around 1 m).udThe actuator is primarily designed to operate in standalone condition and later to use it inudthe 3RPR parallel robot.udA DC motor is used to operate the actuator. A quadrature encoder is attached with the DCudmotor to control the end effector. The associated control scheme of the actuator isudanalyzed and integrated with the physical prototype. From standalone experimentation ofudthe actuator, around 17g acceleration was achieved by the end effector (stroke length wasud0.2m to 0.78m). Results indicate that the developed dynamic model results are in goodudagreement.udFinally, a Design of Experiment (DOE) based statistical approach is also introduced toudidentify the parametric combination that yields the greatest performance. Data areudcollected by using the Bond Graph model. This approach is helpful in designing theudactuator without much complexity.