The equal-area theorem●This is sinusoidal PWM (SPWM)●The equal-area theorem can be appliedto realize any Shape of waveforms
●Natural sampling●Calculation based on equal-area criterion●Selected harmonic elimination●Regular sampling●Hysteresis-band control●Triangular wave comparison withfeedback control
提出一種基于凌陽單片機(jī)的步進(jìn)電機(jī)加減速的控制方法。采用凌陽科技推出的16位結(jié)構(gòu)工控單片機(jī)SPMC75F2413A為控制器，由Allegro公司生產(chǎn)的兩相步進(jìn)電機(jī)專用驅(qū)動器件SLA7042M構(gòu)成步進(jìn)電機(jī)的驅(qū)動電路，在傳統(tǒng)的3段直線加減速控制算法基礎(chǔ)上增加至7段S形曲線加減速過程，控制步進(jìn)電機(jī)的啟動和停止。實驗結(jié)果表明，該控制方法克服了直線加減速中不連續(xù)、易造成系統(tǒng)沖擊的問題，整個系統(tǒng)實現(xiàn)柔性控制，電機(jī)啟動、停止連續(xù)性能提高30%。
Abstract:
The method of controlled stepping motor is referred based on SPMC75F2413A MCU， which adopts the 16 knots SPMC75F2413A MCU as the controller. The special-purpose actuation chip SLA7042M of two stepping motor produced by Allegro Corporation constituted to actuation electric circuit. The purpose of increasing to seven section of S Shape curve based on the traditional three sections of straight line is to control the start and stop process of stepping motor. The experimental results show that the control method solves easy to pull-out and overshot problems. The overall system realizes flexible control， and the performance of motor start or stop continuity is increased 30%
All inputs of the C16x family have Schmitt-Trigger input characteristics. These Schmitt-Triggers are intended to always provide proper internal low and high levels, even if anundefined voltage level (between TTL-VIL and TTL-VIH) is externally applied to the pin.The hysteresis of these inputs, however, is very small, and can not be properly used in anapplication to suppress signal noise, and to Shape slow rising/falling input transitions.Thus, it must be taken care that rising/falling input signals pass the undefined area of theTTL-specification between VIL and VIH with a sufficient rise/fall time, as generally usualand specified for TTL components (e.g. 74LS series: gates 1V/us, clock inputs 20V/us).The effect of the implemented Schmitt-Trigger is that even if the input signal remains inthe undefined area, well defined low/high levels are generated internally. Note that allinput signals are evaluated at specific sample points (depending on the input and theperipheral function connected to it), at that signal transitions are detected if twoconsecutive samples show different levels. Thus, only the current level of an input signalat these sample points is relevant, that means, the necessary rise/fall times of the inputsignal is only dependant on the sample rate, that is the distance in time between twoconsecutive evaluation time points. If an input signal, for instance, is sampled throughsoftware every 10us, it is irrelevant, which input level would be seen between thesamples. Thus, it would be allowable for the signal to take 10us to pass through theundefined area. Due to the sample rate of 10us, it is assured that only one sample canoccur while the signal is within the undefined area, and no incorrect transition will bedetected. For inputs which are connected to a peripheral function, e.g. capture inputs, thesample rate is determined by the clock cycle of the peripheral unit. In the case of theCAPCOM unit this means a sample rate of 400ns @ 20MHz CPU clock. This requiresinput signals to pass through the undefined area within these 400ns in order to avoidmultiple capture events.For input signals, which do not provide the required rise/fall times, external circuitry mustbe used to Shape the signal transitions.In the attached diagram, the effect of the sample rate is shown. The numbers 1 to 5 in thediagram represent possible sample points. Waveform a) shows the result if the inputsignal transition time through the undefined TTL-level area is less than the time distancebetween the sample points (sampling at 1, 2, 3, and 4). Waveform b) can be the result ifthe sampling is performed more than once within the undefined area (sampling at 1, 2, 5,3, and 4).Sample points:1. Evaluation of the signal clearly results in a low level2. Either a low or a high level can be sampled here. If low is sampled, no transition willbe detected. If the sample results in a high level, a transition is detected, and anappropriate action (e.g. capture) might take place.3. Evaluation here clearly results in a high level. If the previous sample 2) had alreadydetected a high, there is no change. If the previous sample 2) showed a low, atransition from low to high is detected now.
All inputs of the C16x family have Schmitt-Trigger input characteristics. These Schmitt-Triggers are intended to always provide proper internal low and high levels, even if anundefined voltage level (between TTL-VIL and TTL-VIH) is externally applied to the pin.The hysteresis of these inputs, however, is very small, and can not be properly used in anapplication to suppress signal noise, and to Shape slow rising/falling input transitions.Thus, it must be taken care that rising/falling input signals pass the undefined area of theTTL-specification between VIL and VIH with a sufficient rise/fall time, as generally usualand specified for TTL components (e.g. 74LS series: gates 1V/us, clock inputs 20V/us).The effect of the implemented Schmitt-Trigger is that even if the input signal remains inthe undefined area, well defined low/high levels are generated internally. Note that allinput signals are evaluated at specific sample points (depending on the input and theperipheral function connected to it), at that signal transitions are detected if twoconsecutive samples show different levels. Thus, only the current level of an input signalat these sample points is relevant, that means, the necessary rise/fall times of the inputsignal is only dependant on the sample rate, that is the distance in time between twoconsecutive evaluation time points. If an input signal, for instance, is sampled throughsoftware every 10us, it is irrelevant, which input level would be seen between thesamples. Thus, it would be allowable for the signal to take 10us to pass through theundefined area. Due to the sample rate of 10us, it is assured that only one sample canoccur while the signal is within the undefined area, and no incorrect transition will bedetected. For inputs which are connected to a peripheral function, e.g. capture inputs, thesample rate is determined by the clock cycle of the peripheral unit. In the case of theCAPCOM unit this means a sample rate of 400ns @ 20MHz CPU clock. This requiresinput signals to pass through the undefined area within these 400ns in order to avoidmultiple capture events.
OFELI is an object oriented library of C++ classes for development of finite element codes. Its main features are : * Various storage schemes of matrices (dense, sparse, skyline). * Direct methods of solution of linear systems of equations as well as various combinations of iterative solvers and preconditioners. * Shape functions of most "popular" finite elements * Element arrays of most popular problems (Heat Transfer, Fluid Flow, Solid Mechanics, Electromagnetics, ...).
人工智能中模糊邏輯算法
FuzzyLib 2.0 is a comprehensive C++ Fuzzy Logic library for constructing fuzzy logic systems with multi-controller support.
It supports all commonly used Shape functions and hedges, with full support for the various types of Aggregation, Correlation, Alphacut, Composition, Defuzzification methods.
The latest version of the C++ Fuzzy Logic Class Library contains all the C++ source code and comes complete with a usage example for building a multi-controllers fuzzy logic model.
