CN1252616C - Position signal processing device - Google Patents

Abstract

The present invention provides a signal processing device, and relates to a processing device for processing a signal of a position sensor. The processing device comprises an analog speed observer (2), a time-varying wave filter (3) and a position detector (4), wherein the analog speed observer (2) provides an analog speed signal Wa by utilizing an A-phase analog signal Sa and a B-phase analog signal Sb output by a position sensor (1), a time-varying wave filter (3) provides an A-phase signal Xa and a B-phase signal Xb by utilizing the analog speed signal Wa, the A-phase analog signal Sa and the B-phase analog signal Sb, and the position detector (4) provides a position signal X by utilizing the A-phase signal Xa and the B-phase signal Xb. As the signal processor of the present invention introduces the analog speed observer (2) and the time-varying wave filter (3), the present invention effectively eliminates the influence of higher harmonic and noise components of the A-phase signal Sa and the B-phase signal Sb. After the position detector (4) carries out signal processing on the A-phase signal Xa and the B-phase signal Xb, the present invention can achieve the purpose of providing the accurate position signal X.

Description

Position signal processor

Technical field: the present invention relates to a kind of processing position transducer (comprising code-disc, grating chi etc.) Signal Processing device; It can be used for detecting the processing of the position status signals of lathe, semiconductor equipment, robot etc.

Background technology: when lathe, semiconductor equipment, robot etc. are carried out position control, generally will after the position situation of utilizing position transducer (comprising code-disc, grating chi etc.) to them detects, the position signal of sensor be handled.Fig. 1 is the structural drawing of existing position signal processor.Position transducer 1 is such as code-disc, grating chi etc., and it can be used for detecting the position situation of lathe, semiconductor equipment, robot etc., provides A phase simulating signal Sa and B simulating signal Sb mutually by it.And A phase simulating signal Sa and B mutually the first-harmonic of simulating signal Sb be respectively sine wave and cosine wave (CW), its frequency is proportional to the speed of detected object, can use formula (1), (2) approximate representation.Sa＝sin(X)……(1)，Sb＝cos(X)……(2)。First shaping circuit 5 is to utilize the A/D transducer that A phase simulating signal Sa is carried out conversion process, and A phase digital signal Xda is provided.Second shaping circuit 6 is to utilize the A/D transducer that B phase simulating signal Sb is carried out conversion process, and B phase digital signal Xdb is provided.Position compositor 7 is to utilize A phase digital signal Xda and B digital signal Xdb mutually, draws position signalling X by arctangent cp cp operation.(2) can accurately represent the A phase simulating signal Sa that obtains from position transducer 1 and B simulating signal Sb mutually, utilizes said apparatus just can draw position signalling X more accurately if (1).But the A phase simulating signal Sa that obtains from position transducer 1 and B be simulating signal Sb mutually, generally all contains higher hamonic wave and noise, can represent more accurately with (3), (4) formula.

$S_a=\sin \left(X\right)+N_a+\underset{i=1}{\overset{M}{\mathrm{\Σ}}}{A}_i\sin ((2i+1)X)\·\·\·\·\·\·\left(3\right),$

$S_b=\cos \left(X\right)+N_b+\underset{i=1}{\overset{M}{\mathrm{\Σ}}}{B}_i\cos \left((2i+1)X\right)\·\·\·\·\·\·\left(4\right),$ Na, Nb are white noise in the formula, and Ai, Bi are the amplitude from 1 to M time higher hamonic wave.Between this and (1), (2) formula very big error is arranged.Generally can suppress for white noise Na, Nb with low-pass filter.But, for higher hamonic wave, owing to be subjected to the influence of the speed dX/dt of measurand, utilize said apparatus just inevitably will be subjected to the higher hamonic wave in (3), (4) formula and the influence of noise component, can not draw accurate position signalling X.

Summary of the invention: purpose of the present invention is exactly to eliminate the influence of higher hamonic wave and noise component effectively, draws accurate more position signalling X.Technical scheme of the present invention is, it includes position transducer 1 and position detector 4, by A phase simulating signal Sa that position transducer 1 is exported and B mutually simulating signal Sb after position detector 4 is handled, provide the signal processing apparatus of position signalling X.This device also comprises and utilizes A phase simulating signal Sa that position transducer 1 exported and B simulating signal Sb mutually, and the analog rate observer 2 of analogue speed signal Wa is provided; Utilize above-mentioned analogue speed signal Wa, above-mentioned A phase simulating signal Sa and above-mentioned B mutually simulating signal Sb the time varying filter 3 of A phase signals Xa and B phase signals Xb is provided; Utilize above-mentioned A phase signals Xa and above-mentioned B phase signals Xb, the position detector 4 of position signalling X is provided.Signal processing apparatus of the present invention, owing to introduced analog rate observer 2 and time varying filter 3, A phase simulating signal Sa and the B higher hamonic wave among the simulating signal Sb and the influence of noise component have mutually been eliminated effectively, make position detector 4 after A phase signals Xa and B phase signals Xb are carried out signal Processing, just can reach the purpose that accurate more position signalling X is provided.

Description of drawings: Fig. 1 is the structural representation of existing signal processing apparatus, and Fig. 2 is the structural representation of the signal processing apparatus of technical solution of the present invention, and Fig. 3 is the structural representation of analog rate observer 2 in the embodiment.

Embodiment: embodiments of the present invention such as Fig. 2, shown in Figure 3, a kind of position signal processor, it utilizes A phase simulating signal Sa that position transducer 1 exported and B simulating signal Sb mutually, and the analog rate observer 2 of analogue speed signal Wa is provided; Utilize above-mentioned analogue speed signal Wa, above-mentioned A phase simulating signal Sa and above-mentioned B be simulating signal Sb mutually, and the time varying filter 3 of A phase signals Xa and B phase signals Xb is provided; Utilize above-mentioned A phase signals Xa and above-mentioned B phase signals Xb, the position detector 4 of position signalling X is provided.Position transducer 1, position detector 4 are identical with existing structure.Analog rate observer 2 is to utilize A phase simulating signal Sa that position transducer 1 exported and B simulating signal Sb mutually, and analogue speed signal Wa is provided.The detailed structure of analog rate observer 2 as shown in Figure 3.Differentiator 8 is to utilize A phase simulating signal Sa that signal Vaa is provided; Differentiator 9 is to utilize B phase simulating signal Sb that signal Vab is provided; Be expressed as follows with (5), (6) formula: Vaa=dSa/dt ... (5); Vab=dSb/dt ... (6).Multiplicative operator 10 is to utilize A phase simulating signal Sa and above-mentioned signal Vab that signal Paa is provided; Multiplicative operator 11 is to utilize B phase simulating signal Sb and above-mentioned signal Vaa that signal Pab is provided.Be expressed as follows with (7), (8) formula: Paa=Sa*Vab ... (7); Pab=Sb*Vaa ... (8).Addition and subtraction arithmetic unit 12 is to utilize above-mentioned signal Paa and above-mentioned signal Pab that signal Wb is provided.Be expressed as follows with (9) formula: Wb=Pab-Paa ... (9).Low-pass filter 13 is to utilize above-mentioned signal Wb, and analogue speed signal Wa is provided.Be expressed as follows with (10) formula: Wa=Wb/ (Ts+1) ... (10).

(10) T is a filter time constant in the formula, and s is a differentiating operator.If ignore the influence of higher hamonic wave and noise component, following formula is set up.Wherein, W is the speed of detected object.

Vaa＝W*cos(W*t)……(11)

Vab＝-W*sin(W*t)……(12)

Paa＝-W*cos(W*t)*cos(W*t)……(13)

Pab＝W*sin(W*t)*sin(W*t)……“(14)

Wb＝W……(15)

Wa＝Wb/(Ts+1)……(16)

Because higher hamonic wave and noise component will show as the high-frequency ac component in Wb, and the speed W of certain relatively detected object will show as DC component.So Wa can will comparatively accurately show the speed W of detected object.Time varying filter 3 is to utilize above-mentioned analogue speed signal Wa, and above-mentioned A phase simulating signal Sa and above-mentioned B be simulating signal Sb mutually, and A phase signals Xa and B phase signals Xb are provided.

Xa＝G(s)Sa……(17)

Xb＝G(s)Sb……(18)

$G\left(s\right)=\frac{1}{T_{G}s+1}\underset{i=1}{\overset{\mathrm{<figure-callout\; id="2"\; label="M\; s"\; filenames="C0313264300062.png,C0313264300063.png"\; state="\{\{state\}\}">M</figure-callout>}}{\mathrm{\&Pi;}}}\frac{s^{}}{}\frac{{}^2+{W_{\mathrm{ci}}}^2}{{\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="C0313264300062.png,C0313264300063.png"\; state="\{\{state\}\}">s</figure-callout>}}^2+Q{W}_{\mathrm{ci}}s+{{\mathrm{<figure-callout\; id="2"\; label="W\; ci"\; filenames="C0313264300062.png,C0313264300063.png"\; state="\{\{state\}\}">W</figure-callout>}}_{\mathrm{ci}}}^2}\&CenterDot;\&CenterDot;\&CenterDot;\&CenterDot;\&CenterDot;\&CenterDot;\left(19\right)$

Wci＝(2*i+1)*Wa……(20)

Because G (s) can adjust the logical frequency of its band according to the variation of the speed W of detected object, thereby can eliminate A phase simulating signal Sa and the B higher hamonic wave among the simulating signal Sb and the influence of noise component mutually effectively.The position signal processor of present embodiment, owing to introduced time varying filter 3 and analog rate observer 2, A phase simulating signal Sa and the B higher hamonic wave among the simulating signal Sb and the influence of noise component have mutually been eliminated effectively, make position detector 4 after A phase signals Xa and B phase signals Xb are carried out signal Processing, just can reach the effect that accurate more position signalling X is provided.

Claims (2)

1, a kind of position signal processor, it includes position transducer (1) and position detector (4), by A phase simulating signal Sa that position transducer (1) is exported and B mutually simulating signal Sb handle through position detector (4) position signalling X be provided, it is characterized in that this device also comprises: utilize A phase simulating signal Sa that position transducer (1) exported and B simulating signal Sb mutually, the analog rate observer (2) of analogue speed signal Wa is provided; Utilize above-mentioned analogue speed signal Wa, above-mentioned A phase simulating signal Sa and above-mentioned B mutually simulating signal Sb the time varying filter (3) of A phase signals Xa and B phase signals Xb is provided; Utilize above-mentioned A phase signals Xa and above-mentioned B phase signals Xb, the position detector (4) of position signalling X is provided.

2, position signal processor according to claim 1, it is characterized in that analog rate observer (2) is to adopt differentiator (8) to utilize A phase simulating signal Sa that signal Vaa is provided, adopt differentiator (9) to utilize B phase simulating signal Sb that signal Vab is provided, adopt multiplicative operator (10) to utilize A phase simulating signal Sa and above-mentioned signal Vab that signal Paa is provided, adopt multiplicative operator (11) to utilize B phase simulating signal Sb and above-mentioned signal Vaa that signal Pab is provided, adopt addition and subtraction arithmetic unit (12) to utilize above-mentioned signal Paa and above-mentioned signal Pab that signal Wb is provided, adopt low-pass filter (13) to utilize above-mentioned signal Wb that analogue speed signal Wa is provided.

Images