Incremental Encoder Speed Acquisition Using an STM32 Microcontroller and NI ELVIS

Abstract

Precise motor control requires high accuracy of the rotor position through the incremental encoder. The speed and accuracy of the acquisition equipment (microcontroller) play an important element in terms of cost and efficiency. In this paper, the author presents alternative methods for speed acquisition from an incremental encoder. In the first stage of research, the main performances of the STM32 microcontroller, connected with an incremental encoder, will be analyzed and compared with two different acquisition systems, i.e., ELVIS II and a Unidrive M701 power inverter. Using the LabVIEW graphical programming language, a user-friendly, convenient, and flexible human–machine interface is designed. Due to the advantages provided by the STM32 microcontroller in terms of processing power, cost, and programming interface, the obtained results are accurate and consistent. Through experimental testing and analysis, the speed acquisition is stable for both developed software algorithms used for ELVIS II and STM32 platforms. It is the aim of the paper to propose a useful speed acquisition tool in low-cost, high-accuracy prototyping applications.

A 19-Bit Small Absolute Matrix Encoder

“…The outer circle, namely circle b, can be divided into 16 code areas, engraving the 5th~19th bit of the traditional code track, and the center angle of each code area is 22.5°. Area 0°~22.5° is the 1st code area, engraving the 19th bit of the traditional code track, engraving 2 13 light-passing strips in the 22.5° circle range, called A19; 22.5°~45° is the 2nd code area, engraving the 18th bit of the traditional code track, engraving 2 12 light-passing strips in the 22.5° circle range, called A18; 45°~67.5° is the 3rd code area, engraving the 17th bit of the traditional code track, engraving 2 11 light-passing strips in the 22.5° circle range, called A17; 67.5°~90° is the 4th code area, engraving the 16th bit of the traditional code track, engraving 2 10 light-passing strips in the 22.5° circle range, called A16; 90°~112.5° is the 5th code area, engraving the 15th bit of the traditional code track, engraving 2 9 lightpassing strips in the 22.5° circle range, called A15; 112.5°~135° is the 6th code area, engraving the 14th bit of the traditional code track, engraving 2 8 light-passing strips in the 22.5° circle range, called A14; 135°~157.5° is the 7th code area, engraving the 13th bit of the traditional code track, engraving 2 7 light-passing strips in the 22.5° circle range, called A13; is the 5th code area, engraving the 15th bit of the traditional code track, engraving 2 9 light-passing strips in the 22.5 • circle range, called A 15 ; 112.5 • ~135 • is the 6th code area, engraving the 14th bit of the traditional code track, engraving 2 8 light-passing strips in the 22.5 • circle range, called A 14 ; 135 • ~157.5 • is the 7th code area, engraving the 13th bit of the traditional code track, engraving 2 7 light-passing strips in the 22.5 • circle range, called A 13 ; 157.5 • ~180 • is the 8th code area, engraving the 12th bit of the traditional code track, engraving 2 6 light-passing strips in the 22.5 • circle range, called A 12 ; 180 • ~202.5 • is the 9th code area, engraving the 11th bit of the traditional code track, engraving 2 5 From the distribution of code tracks, we can easily see that:…”

“…In 2010, Changchun Optical Machine Institute developed an eight-matrix absolute photoelectric encoder, which can realize 10-bit binary coding by engraving a two-circle matrix code track. In 2011, Changchun University of Science and Technology proposed a new matrix encoder solution, which realized 12-bit matrix coding by engraving two circles of matrix code; single-ring Gray code is a perfect encoding, but there are still many theoretical issues that need to be solved urgently [ 4 , 13 ]. Because the m-sequence code has no univariant, there are multi-bit changes between adjacent codes in use.…”

Classification of Optoelectronic Rotary Encoder Faults Based on Deep Learning Methods in Permanent Magnet Synchronous Motor Drive System

“…This chapter presents the optoelectronics encoder model used in simulation stu The model was developed on the basis of the works [35,36]. The main components incremental encoder are the rotating code disc and the optical system, containing mitters-LEDs and receivers-phototransistors (Figure 1) [37,38]. The increments appl the code disc are laser-cut spaces in the metal disc through which the light of the mitter passes.…”