JPS5885113A - Optical type resolver signal generator - Google Patents

Abstract

PURPOSE:To form the highly accurate resolver signal in a simple constitution, by switching optical sine and cosine signals from an incremental shaft encoder by reference sine and cosine signals, thereby forming a phase variable signal. CONSTITUTION:The sine and cosine signals sintheta and costheta are generated (n) times for every one rotation of a shaft by the incremental shaft encoder which is formed by a rotary grating plate 1 and a fixed grating plates 2a and 2b and detected by light emitting elements and light receiving elements 3a and 4a and 4b, and 3b and 4c and 4d. Transistors Tr1 and Tr2 are switched by the reference cosine and sine signals cosomegat and sinomegat which are formed by differential amplifiers Q1a and Q1b, crystal oscillator, and the like. Digital processing is performed in the transistors Tr1 and Tr2, a buffer operation amplifier Q2 and an operation amplifier Q3. Then the phase variable signal sin(omega+theta) is outputted. In this simple constitution without a sliding part, the highly accurate resolver signal is formed by the digital processing by the use of the reference signal based on the crystal oscillator.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical resolver signal generator that uses an incremental shaft encoder to generate a resolver signal (
(variable phase signal).

Incremental shaft encoder serves as angle signal
'cn sine 9 sin θ, cos # signals are generated, and this sin θ, come signal is a perfect sine wave (close to a triangular wave, but can be considered and explained as an approximate sine wave, and there is no problem in practical use. In order to obtain a perfect sine wave signal, it is necessary to create a sine wave-shaped pattern on the rotating grating plate, which requires a large expense in cutting the rotating grating plate.With this invention, the rotating grating plate can be manufactured easily. Using the sin#, cos# signals and the reference signals gina+t, co-ωt, which are generated using the rotating grating plate of a low-cost incremental shaft encoder,
@O Phase variable signal 5in (a+t+#) t- Phase variable signal 5 generated using an electronic circuit and created here
in(ωt+#) has been devised to be effectively used in speed control devices and to reduce calculation costs in order to increase the resolution of encoders, and has an extremely wide range of applications.

The present invention will be described below with reference to the embodiments shown in the drawings.

Incremental shaft encoder t[/As shown in the configuration diagram in the figure, the rotating grating plate/ and the first... JO/pair of fixed grating plates Ja, Jb and l pair of light sources (XJID), J&, Jl
l: fi and 7th, ko, #! 3. It is composed of the second light receiving element (photograph), $6゜*a, and the electronic circuit shown in Fig. 3 or hg+. Now, in FIG. 7, when the U company grating plate l rotates in the direction of the arrow, the source of the light source J1 passing through the fixed grating &/l is the first light receiving element 41IaK input υ21
This becomes the gin# signal in the figure. In addition, there is a lattice with opposite brightness and darkness in the vicinity of the fixed lattice plate core a, which is 8 inch # in Fig. 21.
A double sign is generated in the first light receiving element 41b.

Further, the source of the light source 3b passing through the fixed grating plate enters the third light receiving element +-〇 and becomes a co8θ signal.

Further, a grating having opposite brightness and darkness to that of the first solid foot grating plate B is located close to the first solid foot grating plate B, and generates the coa# in FIG. In addition, the reference signal θ1nωt is shown in FIG.
, OO+I*t f, but these signals are crystal IS
mzigin+1ri was created and used in J0KHghiro. The above sinθ, sin#, cos#.

Coa #, sinωz, 001(alt) are synthesized as shown below using the electronic circuit shown in FIG. 3 to create a variable phase signal -1n(*t+#)'ft.

5infscoaωt+cos#*eina+t=gi
n(*t+#) This variable phase signal -1n (ω is 10) is a IIK sine wave signal shown in FIG. 11, but it can also be used as a rectangular wave signal after waveform shaping. Next, the light receiving element*a
, $b, Tei o, electrical signal from the inspector sin a, s
inθ.

An electronic circuit for modulating and amplifying aOs # and coo # to obtain a variable phase signal will first be shown in JriAK. In this figure, the light source Ll! The original number from JD J&, Jb is photodetector (photo) #1. d), san〇, tei d”cm
The electric signals are each converted and sin# and sin#, oos# and cos# are differentially amplified by the operational amplifier circuits QI&tQtb, respectively, and the light source Ja is generated by differential amplification.

3z Compensation for light intensity fluctuations. The differentially amplified 1n$ and aog# signals are added to the base of the transistor ``rl Ite1.'' and are combined by switching νl using the eoIωi and @inω signals. This signal is
A sine wave O variable phase signal gin (ω is 10) is obtained through an active filter consisting of a buffer operational amplifier circuit Q, a t-channel, and an operational amplifier circuit Q. Another embodiment in which the same output signal as the electronic circuit shown in FIG. 3 can be obtained is shown in FIG.
Direct switching circuit for each LO signal Q4a + Q4
The variable phase signal 81n is switched and synthesized in step 1), inverted and amplified in the operational amplifier circuit Q, and then passed through an accutip filter consisting of an operational amplifier circuit 16'Ls as shown in Fig. 3.
(ωt+#)i is created.

Thus, in this invention, n sine wave signals are changed per revolution using an incremental shaft encoder,
By switching using the reference signal in the t-electronic circuit, it is possible to pass n phase variable signals per rotation.As a result of the above, the present invention has the following features.

That is, first, since it is possible to use a digital signal created by a crystal oscillator as a reference signal, it is possible to create all highly accurate resolver signals.

First, it can operate with a high frequency reference signal.

Third, there is no contact part such as a brush, so reliability is high.

First of all, it is highly reliable because it can use the original 11KL11fD.

First, because the electrical signals from the light-receiving elements are differentially amplified, it is resistant to changes in the amount of light from the light source and changes over time.

Sixth, since the rotating grid plate tube of the incremental shaft encoder is used, it is possible to easily obtain a small sizsolver at a low cost.

Seventhly, the rotation speed can be increased compared to a magnetic resolver.

[Brief explanation of the drawing]

#! Teizu is from this F! FIG. 2 is a block diagram of a circuit diagram showing an embodiment related to i4. In the figure, l is V:AI! Lattice plate 1.21. Cob is a fixed grid plate, J ae J b is a light source, reference a, *b, *c, 4<
d is a light receiving element, Qsa a'Ltb is an operational amplifier circuit,
Q, GL are operational amplifier circuits, 'Lea e GL
ab is a switching circuit.

Claims (1)

[Claims] In an incremental shaft encoder consisting of a light source, a light receiving element, a rotating grating plate, and a fixed grating plate, n signals are generated per revolution. A reference signal alnωt is created using a crystal oscillator or the like for the shaft encoder signal of CO5-. An optical resolver signal generator characterized in that switching is performed by an electronic circuit using COOωtt'.