CN1252616C - Position signal processing device - Google Patents

Abstract

A signal processing device, the invention relates to a processing device for processing position sensor signals. The device also includes: using the A-phase analog signal Sa and B-phase analog signal Sb output by the position sensor (1), an analog speed observer (2) providing an analog speed signal Wa; using the above-mentioned analog speed signal Wa, the above-mentioned A-phase The analog signal Sa and the above-mentioned B-phase analog signal Sb provide a time-varying filter (3) for the A-phase signal Xa and the B-phase signal Xb; use the above-mentioned A-phase signal Xa and the above-mentioned B-phase signal Xb to provide a position detector for the position signal X (4). The signal processing device of the present invention effectively eliminates high-order harmonics and noise components in the A-phase analog signal Sa and B-phase analog signal Sb due to the introduction of the analog speed observer (2) and the time-varying filter (3). , so that the position detector (4) can achieve the purpose of providing a more accurate position signal X after performing signal processing on the A-phase signal Xa and the B-phase signal Xb.

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 position signal processing device, which includes a position sensor (1) and a position detector (4), through which the A-phase analog signal Sa and B-phase analog signal Sb output by the position sensor (1) are passed through the position detector (4) Process and provide the position signal X, which is characterized in that the device also includes: an analog speed observer ( 2); Utilize above-mentioned analog speed signal Wa, above-mentioned A-phase analog signal Sa and above-mentioned B-phase analog signal Sb to provide the time-varying filter (3) of A-phase signal Xa and B-phase signal Xb; Utilize above-mentioned A-phase signal Xa and above-mentioned The B-phase signal Xb provides the position detector (4) of the position signal X. 2. The position signal processing device according to claim 1, characterized in that the analog speed observer (2) uses a differentiator (8) to utilize the A-phase analog signal Sa to provide the signal Vaa, and adopts a differentiator (9) to utilize the B-phase Analog signal Sb provides signal Vab, adopts multiplier (10) to utilize A-phase analog signal Sa and above-mentioned signal Vab to provide signal Paa, adopts multiplier (11) to utilize B-phase analog signal Sb and above-mentioned signal Vaa to provide signal Pab , using the above-mentioned signal Paa and the above-mentioned signal Pab to provide a signal Wb by using the adder-subtractor (12), and using the above-mentioned signal Wb to provide an analog speed signal Wa by using the low-pass filter (13).

Images