A New Seven-Segment Profile Algorithm for an Open Source Architecture in a Hybrid Electronic Platform

José R García-Martínez,Juvenal Rodríguez-Reséndiz,Edson E Cruz-Miguel

doi:10.3390/electronics8060652

José R García-Martínez, Juvenal Rodríguez-Reséndiz + Show 1 more

Open Access

https://doi.org/10.3390/electronics8060652

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Journal: Electronics	Publication Date: Jun 10, 2019
Citations: 11	License type: CC BY 4.0

Affiliation: Autonomous University of Queretaro

Abstract

The velocity profiles are used in the design of trajectories in motion control systems. It is necessary to design smoother movements to avoid high stress in the motor. In this paper, the rate of change in acceleration value is used to develop an S-curve velocity profile which presents an acceleration and deceleration stage smoother than the trapezoidal velocity profile reducing the error at the end of the duty-cycle pre-established in one degree of freedom (DoF) application. Furthermore, a new methodology is developed to generate a seven-segment profile that works with negative velocity and displacement constraints applying an open source architecture in a hybrid electronic platform compounded by a system on a chip (SoC) Raspberry Pi 3 and a field programmable gate array (FPGA). The performance of the motion controller is measured through the comparison of the error obtained in real-time application with a trapezoidal velocity profile. As a result, a low-cost platform and an open architecture system are achieved.

Highlights

The velocity profiles have been studied broadly in recent years to design point-to-point trajectories in robot manipulators, conveyor belts, computer numerical control (CNC) machinery or whatever system with the use of direct current (DC) and alternating current (AC) motors [1,2]
This paper presents a new methodology to obtain the S-curve coefficients in real-time, which includes the non-negative velocity and displacements constraints applied to DC motors using an open architecture based on a Raspberry Pi 3 combined with an field programmable gate array (FPGA) which is a low-cost platform compared to closed architectures on the market capable to generate trajectories
An S-curve velocity profile has been presented for motion control applications implemented in a low-cost platform compounded by a Raspberry Pi 3 and an FPGA

Summary

Introduction

The velocity profiles have been studied broadly in recent years to design point-to-point trajectories in robot manipulators, conveyor belts, computer numerical control (CNC) machinery or whatever system with the use of direct current (DC) and alternating current (AC) motors [1,2]. Velocity profiles have an essential role in motion control since it is possible to accomplish a target position reducing the vibrations and the energy consumption, increasing the precision and the durability of the systems [3,4]. If the velocity changes abruptly, the behavior of acceleration could cause discontinuities in the trajectory [5]. The motion planning designer must develop smoother trajectories to avoid discontinuities in the acceleration and reduce the strain and exertion on the actuators and the mechanical architecture [25,26]. Since a third-degree polynomial models the behavior of the position, the seven-segments velocity profile offers the possibility to maintain the jerk with a constant value, obtaining a step profile for the rate of change in acceleration [27]. It is acceptable to propose a constant value for the jerk according to a given acceleration, but it must exist a relationship with the maximum amount of the speed given by the data-sheet of the actuator

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Conclusion