System identification of a pick-and-place mechanism driven by a permanent magnet synchronous motor

The main objective of this study is to utilize two dynamic models: a mathematical model and a simple model, to identify a pick-and-place mechanism (PPM) which is driven by a permanent magnet synchronous motor (PMSM). In this paper, Hamilton’s principle is employed to derive the mathematical model, which is a nonlinear differential equation, while Newton’s second law is utilized to derive the simple linear model. In system identification, we adopt the real-coded genetic algorithm (RGA) to find not only the parameters of the PPM, but also the PMSM simultaneously. From the identification simulations and experimental results, it is demonstrated that the identification results of the mathematical model present the better matching with the experimental results of the system.     

Trajectory planning based on minimum absolute input energy for an LCD glass-handling robot

The main idea of this paper is to design a novel point-to-point (PTP) trajectory based on minimum absolute input energy (MAIE) for an LCD glass-handing robot, which is driven by a permanent magnet synchronous motor (PMSM). The mechatronic system is described by a mathematical model of electrical and mechanical coupling equations. To generate the MAIE PTP trajectory, we employ a high-degree polynomial and compare with the trapezoidal, cycloidal and zero-jerk trajectories for various constraint conditions, which satisfy their corresponding desired constraints of angular displacement, speed, acceleration and jerk at the start and end times. The real-coded genetic algorithm (RGA) is used to search for the coefficients of high-degree polynomials for the PTP trajectories, and the inverse of absolute input electrical energy is adopted as a fitness function. From numerical simulations, it is found that either increasing the degree number of polynomials or decreasing the constraints at the start and end times will decrease the absolute input electrical energy. The proposed methodology for designing the MAIE PTP trajectory can also be applied to any mechatronic system driven by a PMSM.