DE1474140C - Device for the interpolation of periodic signal sequences - Google Patents

Description

The invention relates to the execution / interpolation of the periods of successive V. lines of a signal generator which ^{emits two approximately sinusoidal signal sequences which are phase-shifted by 1} H) , the interpolation being carried out by doubling the frequency.

The device according to the invention can in particular in systems with quarter-logging, which are used for incremental length measurement and for positioning z. B. serve on machine tools.

In the known systems of this type, the counter or query memory is used to indicate any position controlled with a sine and a cosine signal, which indicate the direction (forward or backward) the movement. A period of, for example, photoelectric or magnetic Sampling of a suitable measuring body corresponds to the full signal Interval length of the graduation of the material measure: This length can be "using the well-known electrical Subdivide the interpolation device in a ratio of 1: 2 or 1: 4. . . -

The aim of the invention is to provide a more extensive interpolation in a total ratio of 1: 8 with an ace to obtain multiple circuit means without changing the conventional signal processing electrical systems with quartering logic would be necessary.

This is achieved according to the invention through the use of a frequency doubler in which on the way of assembling from parts of the original signal sequences double the frequency is generated in phase and independent of frequency.

The invention will now be explained in more detail with reference to FIGS.

1 shows the block diagram of a frequency doubler which can be used for the invention. At the input 1 of the amplifier 2 z. _{B. the sinusoidal voltage S 1} (Fig. 2a) generated by the signal generator, which is not shown, _{and the voltage S 2} (Fig. 2b) also generated by the same signal generator is applied to the input 1 'of the amplifier 2'.

The input signals S ₁ and S ₂ do not need to be sinusoidal or cosine-shaped, but can also be triangular or trapezoidal, for example, without affecting the operation of the arrangement shown in FIG Axis symmetrical signals act.,

With the input signals S ₁ and S ₂ according to the 'F i g. 2a and 2b, the DC voltage components U ₀₁ and U ₀₂ are compensated for by applying a corresponding bias voltage to the amplifiers 2 and 2 ', respectively. _{Furthermore, the inverted signals S 3} (FIG. 3) and S ₄ (FIG. 5) are generated in a known type of phase reversal stage built into the amplifiers 2 and 2 '(not shown in FIG. 1).

_{The frequency doubling of the signal S 1} 'arriving at the output 3 of the amplifier 2 now takes place in the following way:

_{With the inverted signal S 4 present} at the output 4 'of the amplifier 2', a trigger 5 is activated which responds to the zero crossings of the signal. This trigger switches the output 6 of the switching element 7 alternately to the outputs 3 and 4 of the amplifier 2, so that the sawtooth-like signal .V ₅ , drawn in solid lines in FIG. 3, is produced at the output 6. Tnugeiunu to the zero crossing with the help of the rigger 8 then results in FIG. 4 included reverse pump at output I of the device according to FIG. 1..

Line similar square wave voltage, but by ') (! Phase shifted compared to that at output I. outgoing signal and 45 out of phase with the. original input signal from half the frequency, is obtained by rectifying and adding or subtracting the input sine ' b / w. Cosine signals and their inverted signals are generated.

The rectifiers 9, 10, 11 and 12 are used for this purpose and the addition element 13 known per se.

The corresponding selection of the signals is made directly by rectifying the signals S ₁ '(at output 3) or S.,' (at output 3 ') and their inverted signals S ₃ (at output 4) and S ₁ (at output 4) ') achieved. The addition of the rectified voltages yields the triangle-like signal S _n according to FIG.

This signal appearing at the output 14 of the addition part 13 is again triggered by triggering on zero crossing in trigger 15 in that shown in Fig. 6 and at output II of the device F i g. 1 appearing square wave voltage transformed.

The arrangement described above allows two electrical signals phase-shifted by 90 to be amplitude-, To double in the frequency true to phase and zero axis, with very low frequencies (towards 0 Hz) can be processed.

Claims (2)

Patent claims: 1. Device for interpolating the periods of successive waves of a signal generator, which emits two approximately sinusoidal signal sequences phase-shifted by 90 ", with the Interpolation is done by doubling the frequency, characterized by the use a frequency doubler, in which on the way of assembling from parts of the original Signal sequences twice the frequency is generated in a phase-accurate and frequency-independent manner. 2. Device according to claim 1, characterized in that the frequency doubler has an electrical circuit in which from the signals coming from '«inem signal generator (S ₁ , S ₂ ) basic signals (S /, S ₂ ') and inverted signals ( S ₃ , S ₄ ) are generated and a basic signal (S ₁ ') and the associated inverted signal (S.,) are generated in the rhythm of the basic frequency. . are alternately keyed in such a way that a voltage of double frequency is generated whose amplitude, phase and zero axis match the basic signal, and also the two basic _{signals (S 1} ', S,') and their inverted signals (S ₃ , S ₄ ) are rectified, the opposite (or the same) half-waves of the two basic _{signals (S 1} ', S _t ') and their inverted signals (S ₃ , S ₄ ) being passed and added (or subtracted) in such a way that a voltage of double frequency is produced whose amplitude and zero axis match the specified basic signal, but whose phase is shifted by 45 ° compared to that of the basic signal. -