JPS5885116A - Optical type resolver phase shifter - Google Patents

Abstract

PURPOSE:To obtain the highly accurate resolver phase shifter, by performing differential amplification, active filter processing, and the like of the incremental shaft encoder signals from two light sources which are turned ON and OFF by reference sine and cosine signals. CONSTITUTION:The light beams from the light sources LED 2a and 2b are turned ON and OFF by the highly accurate cosine and sine signals cosomegat and sinomegat from a crystal oscillator, received by a pair of light receiving elements 3a and 3b through the incremental shaft encoder 1 formed by a rotary grating 1a and fixed gratings 1b and 1c, and applied to elements 3a and 3b. The outputs of said elements 3a and 3b without electric spark noises are transformed into the signals, which have no light source fluctuation and secular change, by a differential amplifier Q1. The result is processed by an operation amplifier forming an active filter circuit together with a capacitor, a resistor, and the like, and a resolver phase shifting signal sin(omega+theta) is formed, where theta is a phase angle of the resolver shaft. In this way, the optical type resolver phase shifter becomes highly accurate.

Description

DETAILED DESCRIPTION OF THE INVENTION This generator is a resolver shifter that is produced using an interdigital shaft encoder related to an optical resolver phase shifter. Conventionally, a resolver phase shifter by Alljlyll has been used, which consists of one rotor winding and one stator winding in a magnetic core, and the LVC windings have the same amplitude and the same time phase. By applying one voltage of 90 degrees to each coil, a voltage whose phase is temporally shifted by the angle of the single trochanter axis of the resolver is obtained. However, the present invention uses an optical incremental shaft encoder to create a new resolver phase shifter. The optical incremental shaft encoder commonly used in IA produces a single sinusoidal signal (axis/i1). The sine wave signal is not a perfect sine wave, but is close to a triangular wave (to obtain a perfect sine wave, the rotary toothpick of the encoder) needs to create a pattern in the form of a CIE sinusoidal wave. In this generation, if a sine wave signal close to a triangular liquid is used, there will be some error in the output deviation phase variable signal &C, but depending on how it is used, there will be no practical problem, and an encoder that can obtain a perfect sine wave signal will be used. In this case, an accurate variable phase signal can be obtained. The latter case will be explained here. @I diagram is an incrementally shuffled echo coder.
and an electronic circuit J that amplifies and synthesizes the electrical signals, turns on the light source,
Turn off the light source - Path 1>.

First, the narrow mental shaft encoder l is the rotating grating 1 [/tortoise and fixed grating plate/b, za and I pair of light sources Ja
, J), and light receiving elements Ja and Jtl. Now, when the -switch plate l rotates in a predetermined direction, the optical signals snn @l and sim #l from the light source J passing through the fixed grating @is are sent to the first light receiving element JIL.

It enters the first light receiving element 31. Also, the first fixed grid 1 [/@
Ah optical IIJ) optical signal oos $1. aos #l
are the photodetector 3 of II/ and the photodetector JI of $2, respectively.
Enter IIK. As a result, the signal of the light receiving element Ja is six
#l-4-aos #contest, 211 signal is -in #l
+1101 #Kari becomes. Also, the reference signal at 11JIII
1n&t, 001st, this one is also made using a crystal oscillator and costs 11g4$. Furthermore, KsJE is 1L#I, aos#l is gos
The switching transistors turned on and off with mu, stn and st, respectively. The changes in the light intensity of the light source obtained through R, are converted into electrical signals by the light receiving elements Ja and Jll. 5 inches (*t4-
#) is the output signal when the axis is fixed. Such a signal is input to the 10 input terminals of the operational amplifier circuit Q8, where differential amplification is performed, and its output is passed through the active filter circuit of the operational amplifier circuit Q8, and an output signal 9 is output. The output signal obtained here is a phase variable signal 1iin(ω
10), and the phase shifts by an angle - with respect to the reference signal (υ) depending on the position of the encoder axis, so it works as a phase shifter.

Furthermore, if an encoder that can change n sine wave signals in one rotation is used, n phase variable signals can be changed in one rotation. As described above, in the present invention, since it is possible to use a digital IC generated from a crystal oscillator as a reference signal, it is possible to create a resolver signal with a high n degree and good temperature characteristics.

It can operate with a higher frequency reference signal than a magnetic resolver. It is highly reliable because there are no contact parts such as brushes, does not generate noise such as radio noise, and can have a larger rotational speed than a magnetic resolver. Because the electrical signals from the light-receiving elements are differentially amplified, it is resistant to changes in the light intensity of the light source and changes in the seams.Since the optical signals are turned on and off, there is no spike noise caused by switching in the electrical signals. It brings about .

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of the configuration of an embodiment according to the present invention, and Fig. 1 is a diagram of signal waveforms of relevant parts. Fixed grating plate, C is a light source circuit, 11J) is a light receiving element, J is a synthetic amplifier circuit, ql is a differential multiplication m times m%ζ is an operational amplifier circuit. Hour hand applicant Tamagawa Seiki Co., Ltd.

Claims (1)

[Claims] An incremental shaft encoder that can obtain Ijn sine wave signals per revolution, such as 111 light sources, one gIL element, one grating plate and one toothpick plate, and The light source that can be turned on and off separately using the reference signals @6JI・t and 1nωt1 and input to the #1 light receiving element, and the electrical signal of the light receiving element of the #1 light receiving element are differentiated. An optical resolver phase shifter is provided with an operational amplifier which dynamically amplifies the signal and outputs it as an output elm(#t+1) through an active filter circuit.