JPS62214318A - Position information generating device - Google Patents

Abstract

PURPOSE:To generate high-accuracy position information by a simple circuit at low cost by generating a trigger signal corresponding to the leading or trailing edge of a reference angle output signal according to the direction state of the forward or backward rotation of the relation between two phase signal outputs. CONSTITUTION:A rotary encoder 3 generate incremental type position information which includes the two phase signals having a 90 deg. phase difference and reference angle output signal. A count pulse generating circuit 13 provided to a counter circuit part 2 generates pulse signals corresponding to the leading edge and trailing edge of the two phase signals and sends them out to a counter 12. A reference value which is the initial value of the counter 12 is set in the register 10 of a reference value setting part 4. Then, an edge trigger circuit 14 corresponds to the leading edge of the reference angle output signal when the relation between the two phase signal output indicates forward rotation or to the tailing edge of the reference angle output signal when backward rotation, thereby generating the trigger signal at the timing of the leading or trailing edge. The reference value is sent of the register 10 through a gate circuit 11 according to the trigger signal and set in the counter 12.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a position information generating device, and in particular, performs relatively highly accurate position 1δ control or measurement using a two-phase signal and a reference signal output from an incremental rotary encoder. The present invention relates to a rotational position position information generating device suitable for a device.

[Prior Art] This type of position information generating device is used in angle measuring devices, positioning devices, and the like. As an example, a rotation amount generating device that generates rotation amount information will be explained with reference to the block diagram of FIG. 5.

1 is a rotation amount generating device, 2 is a counter circuit thereof, and 3 is a rotary encoder.

The counter circuit unit 2 receives an output signal from the rotary encoder 3 according to its rotation and generates tachometer information.

Examples of the rotary encoder include an absolute type that generates the amount of rotation as code data, and an incremental type that has a two-phase signal output with a 90 degree phase difference and a reference angle output.

Here, if the rotary encoder 3 is an incremental type, as shown in FIG. 6(a), the A-phase signal 6, which is one of the two-phase output pulses from the rotary encoder 3, and (b) As you can see, the B phase signal 7 is
The counter circuit section 2 is manually operated to generate a count pulse signal 8 shown in FIG. 2(d), which is counted by the counter of the counter circuit section 2.

From the rotary encoder 3, a Z-phase signal 5 as a reference angle output signal shown in FIG. 6(C) is sent to the counter circuit section 2, and each time this signal is input, the counter of the counter circuit section 2 is cleared. or set to a predetermined value.

On the other hand, in the counter circuit section 2, the two-phase output is applied to the direction discrimination circuit, and a checkered pulse or a reverse pulse is generated from the relationship between these two-phase outputs. The counter built in the counter circuit section 2 counts up the number of count pulse signals 8 in response to the forward rotation pulse, and counts down the number in response to the reverse rotation pulse.

[Problem to be Solved] By the way, the Z-phase signal 5 shown in FIG.
The period λ of the level (hereinafter referred to as "H") has a certain range. Here, if the length of one cycle of the A-phase signal 6 or B-phase signal 7 is P, the waveform of this Z-phase signal 5 is:
It is generally indeterminate in the range of 1/2·P to 3/2-P.

As a result, the count pulse signal 8 is actually generated during the period (interval λ) during which the two-phase signal 5 is “H” (significant).
Without being counted, it continues to take zero or the initialized value n as shown in Fig. 6().In other words, the actual count pulse becomes as shown in Fig. 6(e) and as shown in Fig. 6(f). ), the pulse is counted with missing pulses.

In FIG. 6(f), the actual count remains constant while six pulses are input, and the five uncounted pulses remain as an offset without being added to subsequent counts. As a result, this causes a decrease in accuracy.

Therefore, when attempting to perform positioning or measurement with higher precision in a device that performs positioning or measurement using such an encoder, it is necessary to take this missing part into consideration from the beginning.

However, in this case, separate reference values must be set because the counter additions and subtractions are reversed during forward rotation and reverse rotation (or in positive and negative directions). ° The length of the "H" period λ also needs to be measured before π, which is complicated, and there is a drawback that special processing or complicated circuits are required.

[Purpose of the Invention] The present invention has been made in view of the problems of the prior art, and it solves the problems of the prior art and provides a highly accurate circuit with a simple rattan circuit. It is an object of the present invention to provide a location information generating device that can generate location information and is inexpensive.

[Means for Solving the Problems] The means in the position information generating device of the present invention for achieving such an object is to generate a two-phase output signal and a reference angle output signal having a phase difference of 90 degrees. An encoder that generates incremental type position information and a 2-phase output 43
A count pulse generation circuit that generates a pulse signal corresponding to the rise of \γ and the fall of )'L of the number, a counter that receives the pulse signal and counts the number of pulse signals, and a storage section that stores the initial value of this counter. When the relationship between the two-phase output signals is in a predetermined one direction state, a trigger signal is generated in response to the timing of one edge of the reference angle output signal, and when the relationship between the two-phase output signals is in a predetermined other direction state, a trigger signal is generated. The device includes a trigger circuit that generates a trigger signal in response to the timing of the other edge of the reference angle output signal, and sets a reference value in a counter in response to the trigger signal.

[Function] In this way, when the relationship between the two-phase signal outputs is in one direction state, the bird generates a signal in response to one edge of the reference angle output signal, and when it is in the other direction state, the bird generates a signal in response to the reference angle output signal. By providing a trigger circuit that generates a trigger signal in response to the other edge of the output signal, a reference value can be set in the counter at a constant edge timing position in the reference angle output signal. Therefore, the width of the reference angle signal almost never spans a plurality of count pulses.

Further, by doing so, it is possible to prevent errors in setting the reference of the counter, and it is possible to realize a highly precise angle measuring device or a positioning device. In addition, there is no need to make major changes to the conventional circuit, and the additional circuit is not complicated, making it inexpensive.

[Embodiment] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of a rotation generating device to which the present invention is applied, and FIG. 2 is an operation timing chart thereof,
FIG. 3 is a block diagram of an example of the specific circuit, and FIG. 4 is an explanatory diagram of the rotary encoder installed state. Note that the same parts as in FIGS. 5 and 6 are indicated by the same reference numerals.

In FIG. 1, 4 is a reference value setting section, and a register 10 corresponding to a set value is provided inside. A reference value as the initial count value of the counter is set in this register 10, and the reference value is sent to the counter 12 of the counter circuit section 2 via the gate circuit 11 and set therein.

On the other hand, 2 which is the reference angle output of the rotary encoder 3
Phase signal 5 and A phase signal 6 of two-phase output. What is B-phase signal 7?
They are similar to those in FIGS. 6(a) and (b), respectively, and the A-phase signal 6. shown in FIG. 2(a). The B-phase signal 7 shown in (b) is input manually to the counter circuit section 2.

Reference numeral 13 denotes a count pulse signal generation circuit provided in the counter circuit section 2, which outputs a two-phase A-phase signal 6. Upon receiving the B phase signal 7 (see Fig. 2 (a) and (b) I),
A count pulse signal and a rotation direction signal are sent to the counter 12.

Reference numeral 14 denotes an edge trigger circuit, into which the two-phase output signal 5 from the rotary encoder 3 is input, and sends out a trigger signal 9 to the gate circuit 11 and the counter 12 of the counter circuit section 2.

Here, the edge trigger circuit 14 generates a trigger signal 9 at a timing position corresponding to the edge position S on one side of the reference angle output, regardless of whether the rotary encoder 3 rotates forward or backward.
(see FIG. 2(C)'), which is the A-phase signal 6. B phase signal 7 (Fig. 2 (a), (b)
)), when the relationship between the two-phase signal outputs is in the forward rotation direction, the reference angle output signal X7. Corresponding to the rise (leading edge), trigger signal 9 is generated at this timing, and these two
When the relationship between the phase signal outputs is in the reverse direction, it corresponds to the falling edge (trailing edge) of the reference angle output signal, which means that the trigger signal 9 is generated at this timing.

Next, the overall operation will be explained.

Now, when the reference angle signal 5 output from the rotary encoder 3 is input manually to the edge trigger circuit 14, the edge trigger circuit 14 detects the rising edge of the input signal during forward rotation, and detects the falling edge of the input signal during reverse rotation. , generates a trigger signal 9 upon detection.

In this embodiment, the reference angle signal 5 in FIG. 2(c)
The bird generates the signal 9 at that timing by using the front edge of the front edge (which becomes the front side in the forward rotation state), but this trigger (no. The rear edge of the angle signal 5 may be used as shown in FIG.

This trigger signal 9 is sent to the counter circuit section 2 as a reference value setting signal, and is also sent to the reference value setting 2 as an enable signal.
It is output to the gate circuit 11 provided at the midpoint of <10.

Here, when the timings of the gate circuit 11 and the counter 12 do not match, the set signal is converted into the signal 9 by the bird as a set signal of the counter circuit section 2 or a logic signal matched with the enable of the gate circuit 14. By doing this, you can adjust the timing of each.

Now, the trigger signal 9 shown in FIG. 2(C)' is sent to the counter circuit section 2, and when this is input, the gate circuit
The reference value from is stored in the counter. On the other hand, the counter pulse generation circuit 13 rotates in the normal direction.

A direction signal indicating reversal and a count pulse signal 8 are sent to the counter 12 of the counter circuit section 2.

Therefore, the counter 12 counts up the number of input pulse signals 8 when a forward rotation pulse arrives, and counts down when a reverse rotation pulse arrives.

When the reference angle output is generated from the rotary encoder 3 in this way, the trigger signal 9 is generated corresponding to the position of the edge S on one side of the reference angle output, both during forward rotation and during reverse rotation, and at this timing. Accordingly, a reference value is set in the counter 12 as its initial value, and the counter 12 uses this value as a reference, and uses the reference value set according to the forward or reverse rotation of the rotary encoder 3 during forward rotation or reverse rotation as a reference. The counter pulse signal 8 shown in FIG. 2(d) is added/subtracted and counted.

As can be understood from FIGS. 2(c) and 2(c)', by providing the edge trigger circuit 14, the trigger signal 9 is generated as a signal for loading the reference value into the count, which is essentially a two-phase signal. 5 is in HIT. Therefore, the actual count pulse for count pulse signal 8 becomes as shown in the same figure (e), which almost prevents missing count pulses when setting the reference value. I can do it.

The actual count value in this case is as shown in FIG. 2(f).

Note that the width of the trigger signal 9 can be arbitrarily set by adjusting it with the edge trigger circuit 14.

By the way, as shown in FIG. 4, the rotary encoder 3 adjusts the angle (or position) of an arm joint, etc.
t11 It is attached to the rotating part that you want to stabilize.

In the case of position measurement, it is attached to a moving member (carriage) or the like, and the amount of linear movement thereof is transmitted to the shaft of the rotary encoder 3 via a gear or the like and detected as a rotating part.

Here, P indicates the angle reference position of the rotary encoder 3, and Q indicates the rotation reference position of the arm. The angle 0 indicates the amount of deviation between these, and the value corresponding to this deviation angle 0 is set in the register 10 by the setting unit 4.The set value is the reference value setting. The value can be arbitrarily selected by the unit 4, and the value is selected depending on the installation state of the rotary encoder 3.

Here, when the rotary encoder 3 is attached to an actual arm rotation part, etc., the two-phase generation position P does not necessarily correspond to the position Q that is desired as the rotation reference of the arm or the like. In such a case, even if you change the mounting state on the rotary encoder 3 side, the mounting state is still 12, for example.
Since each rotation is 0 degrees, positioning cannot be performed freely.

In particular, the wiring from the rotary encoder 3 and surrounding members get in the way, limiting the mounting state. Therefore, the rotary encoder becomes less convenient to use. However, if a reference value setting section is provided as in this embodiment so that the initial value can be set freely or selectively on the counter, the rotation amount (or positioning@) can be determined with high accuracy and ease of use. This means that a generator can be realized.

FIG. 3 shows an example of a circuit similar to the one shown in FIG. 1. Here, a digital switch 20 is used as the reference value setting section 1, a multivibrator 21 is used as the edge trigger circuit 14, and the set signal 22 of the counter section is a gate circuit with negative logic provided at the midpoint of the reference value 4. The enable signal No. 11 uses positive logic. The counter circuit section 2 is designed to take in the 4-bit value set by the digital switch 20 as a reference value only when set No. 43 23 is input.

Note that the circuit in Figure 3 mainly shows the operation of the N'IIE rotation side, and when reversing, a similar multivibrator is provided so that it operates with the X''L falling.
Make selections using i[rotation and reversal, respectively.

In this way, by simply adding a few circuits to the conventional circuit,
Accuracy during standard setting can be ensured.

By the way, there are cases where the reference setting unit 4 is used for setting by a program, but even in this case, errors can be prevented by using a wooden sword type in which an archival circuit is provided.

As described above, in this embodiment, the edge trigger circuit adopts a timing position on the 2nd edge of the rising edge during forward rotation; It may be on the dodgy side. In this case, when the logic is negative or reversed, the timings of rising and falling are reversed. Therefore, in general, it is sufficient to use either the old edge or the trailing edge of the reference pulse signal for the iE forward rotation, and the other for the reverse rotation.

Furthermore, the edge trigger circuit can also be constructed of, for example, a flip-flop circuit, a one-shot circuit, an inverter, and the like. In other words, the one-shot circuit is driven by the 1 "rise of fall" signal, and its output is input to the gate circuit as a trigger signal for forward rotation, and a flip-flop circuit is set to generate the rising pulse for reverse rotation. By setting the flip-flop circuit, the inverter circuit can invert the next falling pulse to drive the one-shot circuit and generate a trigger signal.

In addition, the directional signal is obtained from the two-phase output from the rotary encoder, and the rising signal (or falling signal) is selected during forward rotation to generate a trigger signal, and the rising signal during reverse rotation is the opposite of that during forward rotation. The trigger signal may be obtained by selecting a falling signal (or a falling signal), and this can be easily realized by combining various logic circuits.

In addition, although the embodiment mainly describes a rotation amount generating device suitable for angle measurement, etc., it is also possible to generate position information using an encoder when detecting information on the position 1δ of a linearly moving member moving on a straight line. Of course, it can also be applied to other devices.

Therefore, the present invention is not limited to the generation of information regarding rotational position (it can be applied to various position information generation devices that use encoders that generate so-called incremental type position information).

Further, in the embodiment, the counter and the counter pulse generation circuit are explained as being separate, but it goes without saying that these may be an integrated circuit.

[Effects of the Invention] As can be understood from the explanation in 1-1, in this invention, when the relationship between the two-phase signal outputs is in one direction, the trigger is triggered in response to one edge of the reference angle output signal. By providing a trigger circuit in which the trigger circuit generates a signal corresponding to the other edge of the reference angle output signal when in the other direction state, the trigger circuit generates a signal corresponding to the other edge of the reference angle output signal. , a reference value can be set in the counter. Therefore, the width of the reference angle signal rarely spans a plurality of count pulses.

Further, by doing so, it is possible to prevent errors in setting the reference of the counter, and it is possible to realize a highly accurate angle measuring device or positioning device. In addition, there is no need to make major changes to the conventional circuit, and the additional circuit is not complicated, making it inexpensive.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a rotation information generating device to which the present invention is applied, FIG. 2 is an operation timing chart thereof, and FIG.
The figure is a block diagram of an example of the specific circuit, FIG. 4 is an explanatory diagram of the rotary encoder installation state, and FIG. 5 is an example of a rotary lJ3 information generating device using a conventional rotary encoder. The explanatory diagram, FIG. 6, is its operation timing chart. ■...Rotation amount generator, 2...Counter circuit section, 3
...Rotary encoder, 4...Reference value, 5...
Reference angle output signal, 6... Output pulse A phase signal, 7.
...Output pulse B-phase signal, 8.Counter input pulse signal, 9.Trigger signal, 10.Reference value setting section, lO.Register, 11.
...Gate circuit, 12a...Counter, 12b...
- Counter pulse generation section, 14...edge trigger circuit.

Claims (3)

[Claims] (1) An encoder that generates incremental type position information having a two-phase output signal with a 90 degree phase difference and a reference angle output signal, and generates pulse signals corresponding to the rise and fall of the two-phase output signal. a count pulse generation circuit, a counter that receives the pulse signal and counts the number of pulse signals, a storage section that stores an initial value of the counter, and a relationship between the two-phase output signal that is in a predetermined one-way state. In one case, the trigger signal is generated in response to the timing of one edge of the reference angle output signal, and in a predetermined other direction state, the trigger signal is generated in response to the timing of the other edge of the reference angle output signal. and a trigger circuit that generates a trigger signal according to the trigger signal, and sets the reference value in the counter in response to the trigger signal. (2) The encoder is a rotary encoder, and the count pulse generation circuit receives two-phase output signals and generates pulse signals corresponding to the rising and falling edges of these output signals and a direction signal indicating the forward or reverse rotation direction of the rotary encoder. The counter adds or subtracts according to the direction signal and the pulse signal, and the reference value is set in the counter via a gate circuit that is opened by a trigger signal. A position information generating device according to claim 1. (3) The position information generating device according to claim 2, wherein the reference value is set according to the installation state of the rotary encoder.