CN101551691A - PWM arithmetic and device for arbitrary function waveform generation - Google Patents

Abstract

The invention discloses a PWM arithmetic and a device for arbitrary function waveform generation, which are used for fitting waveforms by a DSP platform. The PWM arithmetic comprises the following steps of setting the function, converting the function, calculating the function value and obtaining a PWM fitting result; and the device comprises a function setting device, a function conversion device, a function value calculating device and an output device which are connected in sequence. The invention satisfies the waveform requirements of high precision and low noise and can fit the waveforms well by the DSP platform.

Description

PWM algorithm and device thereof that a kind of arbitrary function waveform takes place

Technical field

The present invention relates to a kind of method for generation and device thereof of arbitrary function waveform, relate in particular to PWM algorithm and device thereof that a kind of arbitrary function waveform takes place.

Technical background

Existing function waveform generating means often can not reach high precision, low noise waveform requirement at some to the demanding occasion of accuracy of waveform, how to satisfy high precision, low noise waveform requirement is a problem demanding prompt solution of the present invention.

Summary of the invention

The objective of the invention is to overcome the defective of prior art, and PWM (width modulation) algorithm and the device thereof that provide a kind of arbitrary function waveform to take place, it has satisfied high precision, and low noise waveform requirement can utilize DSP platform match waveform well.

The technical scheme that realizes above-mentioned purpose is:

The PWM algorithm that a kind of arbitrary function waveform of one of the present invention takes place comes the match waveform by a DSP platform, and wherein, it may further comprise the steps:

Step S1 is provided with function, is T to the cycle that will produce promptly, and amplitude is that the arbitrary function of Vm is set to Vmf (t-kT);

Step S2 transforms function, and the function that is about to be provided with among the step S1 carries out amplitude mark 1, and establishing maximum amplitude is V _M, arbitrary function is converted into KV _MF (t-kT), wherein, $K=\frac{V_m}{V_M};$

Step S3, the computing function value is promptly calculated functional value f (n Δ t-kT)=g (n) of 125 according to the exponent number formula, and wherein, described exponent number formula launches for the exponent number that function f (t-kT) is carried out in 256 dot cycles, for:

$\left\{\begin{array}{cc}f(\mathrm{n\Δt}-\mathrm{kT})=f^{,}(\mathrm{n\Δt}-\mathrm{kT})\·\mathrm{\Δt}& n=2i+1\\ f(\mathrm{n\Δt}-\mathrm{kT})=0& n=2i\end{array}\right.$

Wherein, i=0,1,2 ... 128;

Step S4 draws the PWM fitting result, promptly according to the described KV of step S2 _MF (t-kT) can obtain $\frac{K\·V_M\·g\left(n\right)}{V_M}=K\·g\left(n\right)$ Dutycycle, promptly obtained the PWM fitting result of arbitrary function, wherein, g (n) is a feedback signal.

The PWM device that the present invention's two a kind of arbitrary function waveform takes place comes the match waveform by a DSP platform, and wherein, it comprises functional unit is set, transforms functional unit, computing function value device and output unit of linking to each other successively, wherein:

The described functional unit that is provided with, be used for to the cycle that will produce be T, amplitude is that the arbitrary function of Vm is set to Vmf (t-kT);

Described conversion functional unit is used for carrying out amplitude mark 1 with the function that functional unit is provided with is set, and establishing maximum amplitude is V _M, arbitrary function is converted into KV _MF (t-kT), wherein, $K=\frac{V_m}{V_M};$

Described computing function value device is used for functional value f (n Δ the t-kT)=g (n) according to 125 of exponent number formula calculating, and wherein, described exponent number formula launches for the exponent number that function f (t-kT) is carried out in 256 dot cycles, for:

$\left\{\begin{array}{cc}f(\mathrm{n\Δt}-\mathrm{kT})=f^{,}(\mathrm{n\Δt}-\mathrm{kT})\·\mathrm{\Δt}& n=2i+1\\ f(\mathrm{n\Δt}-\mathrm{kT})=0& n=2i\end{array}\right.$

Wherein, i=0,1,2 ... 128;

Output unit is used to export the PWM fitting result, promptly according to transforming the KV described in the functional unit _MF (t-kT) can obtain $\frac{K\·V_M\·g\left(n\right)}{V_M}=K\·g\left(n\right)$ Dutycycle, promptly obtained the PWM fitting result of arbitrary function, wherein, g (n) is a feedback signal.

The invention has the beneficial effects as follows: the present invention utilizes DSP (digital signal processor) platform simulation waveform, by function being set, transforming function, computing function value, draw the PWM fitting result of arbitrary function at last, the waveform of generation has high precision, low noise advantage.

Description of drawings

Fig. 1 is a process flow diagram of the present invention;

Fig. 2 is a structural representation of the present invention.

Embodiment

The invention will be further described below in conjunction with accompanying drawing.

See also Fig. 1, there is shown PWM (width modulation) algorithm of a kind of arbitrary function waveform generation of one of the present invention, come the match waveform by a DSP (digital signal processor) platform, it may further comprise the steps:

Step S1 is provided with function, is T to the cycle that will produce promptly, and amplitude is that the arbitrary function of Vm is set to Vmf (t-kT);

Step S2 transforms function, and the function that is about to be provided with among the step S1 carries out amplitude mark 1, and establishing maximum amplitude is V _M, arbitrary function is converted into KV _MF (t-kT), wherein, $K=\frac{V_m}{V_M};$

Step S3, the computing function value is promptly calculated functional value f (n Δ t-kT)=g (n) of 125 according to the exponent number formula, and wherein, described exponent number formula launches for the exponent number that function f (t-kT) is carried out in 256 dot cycles, for:

$\left\{\begin{array}{cc}f(\mathrm{n\Δt}-\mathrm{kT})=f^{,}(\mathrm{n\Δt}-\mathrm{kT})\·\mathrm{\Δt}& n=2i+1\\ f(\mathrm{n\Δt}-\mathrm{kT})=0& n=2i\end{array}\right.$

Wherein, i=0,1,2 ... 128;

Step S4 draws the PWM fitting result, promptly according to the described KV of step S2 _MF (t-kT) can obtain $\frac{K\·V_M\·g\left(n\right)}{V_M}=K\·g\left(n\right)$ Dutycycle, promptly obtained the PWM fitting result of arbitrary function, wherein, g (n) is a feedback signal.

See also Fig. 2, there is shown the PWM device that the present invention's two a kind of arbitrary function waveform takes place, come the match waveform by a DSP platform, it comprises successively functional unit 1 is set, transforms functional unit 2, computing function value device 3 and output unit 4 of linking to each other, wherein:

Functional unit 1 is set, be used for to the cycle that will produce be T, amplitude is that the arbitrary function of Vm is set to Vmf (t-kT);

Transform functional unit 2, be used for carrying out amplitude mark 1 with the function that functional unit is provided with is set, establishing maximum amplitude is V _M, arbitrary function is converted into KV _MF (t-kT), wherein, $K=\frac{V_m}{V_M};$

Computing function value device 3 is used for functional value f (n Δ the t-kT)=g (n) according to 125 of exponent number formula calculating, and wherein, the exponent number formula launches for the exponent number that function f (t-kT) is carried out in 256 dot cycles, for:

$\left\{\begin{array}{cc}f(\mathrm{n\Δt}-\mathrm{kT})=f^{,}(\mathrm{n\Δt}-\mathrm{kT})\·\mathrm{\Δt}& n=2i+1\\ f(\mathrm{n\Δt}-\mathrm{kT})=0& n=2i\end{array}\right.$

Wherein, i=0,1,2 ... 128;

Output unit 4 is used to export the PWM fitting result, promptly according to the KV that transforms in the functional unit 2 _MF (t-kT) can obtain $\frac{K\·V_M\·g\left(n\right)}{V_M}=K\·g\left(n\right)$ Dutycycle, promptly obtained the PWM fitting result of arbitrary function, wherein, g (n) is a feedback signal.

Below embodiment has been described in detail the present invention in conjunction with the accompanying drawings, and those skilled in the art can make the many variations example to the present invention according to the above description.Thereby some details among the embodiment should not constitute limitation of the invention, and the scope that the present invention will define with appended claims is as protection scope of the present invention.

Claims (2)

1. the PWM algorithm that arbitrary function waveform takes place comes the match waveform by a DSP platform, it is characterized in that it may further comprise the steps:

Step S1 is provided with function, is T to the cycle that will produce promptly, and amplitude is that the arbitrary function of Vm is set to Vmf (t-kT);

Step S2 transforms function, and the function that is about to be provided with among the step S1 carries out amplitude mark 1, and establishing maximum amplitude is V _M, arbitrary function is converted into KV _MF (t-kT), wherein, $K=\frac{V_m}{V_M};$

Step S3, the computing function value is promptly calculated functional value f (n Δ t-kT)=g (n) of 125 according to the exponent number formula, and wherein, described exponent number formula launches for the exponent number that function f (t-kT) is carried out in 256 dot cycles, for:

$\left\{\begin{array}{cc}f(\mathrm{n\Δt}-\mathrm{kT})=f^{,}(\mathrm{n\Δt}-\mathrm{kT})\·\mathrm{\Δt}& n=2i+1\\ f(\mathrm{n\Δt}-\mathrm{kT})=0& n=2i\end{array}\right.$

Wherein, i=0,1,2 ... 128;

Step S4 draws the PWM fitting result, promptly according to the described KV of step S2 _MF (t-kT) can obtain $\frac{K\·V_M\·g\left(n\right)}{V_M}=K\·g\left(n\right)$ Dutycycle, promptly obtained the PWM fitting result of arbitrary function, wherein, g (n) is a feedback signal.

2. the PWM device that takes place of an arbitrary function waveform comes the match waveform by a DSP platform, it is characterized in that, it comprises functional unit is set, transforms functional unit, computing function value device and output unit of linking to each other successively, wherein:

The described functional unit that is provided with, be used for to the cycle that will produce be T, amplitude is that the arbitrary function of Vm is set to Vmf (t-kT);

Described conversion functional unit is used for carrying out amplitude mark 1 with the function that functional unit is provided with is set, and establishing maximum amplitude is V _M, arbitrary function is converted into KV _MF (t-kT), wherein, $K=\frac{V_m}{V_M};$

Described computing function value device is used for functional value f (n Δ the t-kT)=g (n) according to 125 of exponent number formula calculating, and wherein, described exponent number formula launches for the exponent number that function f (t-kT) is carried out in 256 dot cycles, for:

$\left\{\begin{array}{cc}f(\mathrm{n\Δt}-\mathrm{kT})=f^{,}(\mathrm{n\Δt}-\mathrm{kT})\·\mathrm{\Δt}& n=2i+1\\ f(\mathrm{n\Δt}-\mathrm{kT})=0& n=2i\end{array}\right.$

Wherein, i=0,1,2 ... 128;

Output unit is used to export the PWM fitting result, promptly according to transforming the KV described in the functional unit _MF (t-kT) can obtain $\frac{K\·V_M\·g\left(n\right)}{V_M}=K\·g\left(n\right)$ Dutycycle, promptly obtained the PWM fitting result of arbitrary function, wherein, g (n) is a feedback signal.

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