Development of an Electronic Controller Applied to a Robotized Manipulator through the Spi Protocol

Purpose In this paper the design and implementation of an embedded control system, using DSCs (Digital Signal Controller) devices of dsPIC type, applied on a four-DOF (Degrees Of Freedom) model OWI-535 robotic manipulator is presented. Design/Methodology/Approach The mathematical model of manipulator is elaborated obtaining joint trajectories to achieve the tracking of a test Cartesian trajectory. A control structure based on a Master/Slave configuration, between two dsPIC30F4013 through SPI (Serial Peripheral Interface) protocol is developed. In such a system, algorithms are implemented: PID (Proportional Integral Derivative) with anti-windup and, generation PWM (Pulse-Width Modulation) and data acquisition, in the DSCs master and slave, respectively. Findings Taking advantage of the high transmission speed of SPI communications and of the quick response of the dsPIC30F4013 DSC, which makes up the embedded system, it is possible to reduce the error correction time of the robot's joint position and to eliminate the vibrations of the actuators, achieving settlement of the desired position quickly and smoothly. This is achieved through two work zones to produce PWM signals: in the first one PWM signals are generated with high duty cycle for a calculated time, and in the second one PWM signals are produced in an exponentially decreasing duty cycle to achieve the desired position. Practical implications The embedded control system that is developed makes it possible to increase the response speed and accuracy, and to provide autonomy to a four-DOF model OEI-535 robotic manipulator, ignoring, for example, as a control element, the use of a