JP3201238B2 - Speed detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speed detecting device for a motor or the like.

[0002]

2. Description of the Related Art In recent years, for detecting the speed of a motor or the like, a rotation pulse generator for outputting a pulse signal having a frequency proportional to the number of rotations thereof has been provided, and a speed detection device for calculating the speed from the cycle of the pulse signal has been widely used. It's being used.

[0003] A conventional speed detector of this type will be described below. FIG. 8 is a block diagram of a conventional speed detecting device. In FIG. 8, a rotation pulse generator 2 outputs a pulse signal c having a frequency proportional to the number of revolutions of the motor 1, and an edge detection circuit 3 detects a rising edge of the pulse signal c to detect an edge detection signal d. The cycle measurement counter 4 measures the input cycle of the edge detection signal d, and writes the result to the internal cycle data register 5.

A central processing unit (hereinafter referred to as a CPU)
Numeral 6 reads out the measured cycle data from the cycle data register 5 via the data bus 7 and calculates the speed based on this data.

FIG. 9 shows a specific configuration example of the rotation pulse generator 2. In FIG. 9, the ring-shaped magnet 2a is fixed to the rotating shaft of the motor 1,
It rotates at the same speed as.

The magnetic sensor 2b is fixed to the frame of the motor 1, and is disposed so as to maintain a certain small gap with the ring magnet 2a in order to detect the magnetism of the ring magnet 2a. .

The output signal of the magnetic sensor 2b is formed into a pulse waveform via a waveform processing circuit (not shown) to form a rotation pulse signal c.

The operation of the above configuration will be described. FIG. 10 is a time chart showing signal waveforms of various parts when the motor 1 is rotating. Since the ring-shaped magnet 2a is fixed to the rotation shaft of the motor 1, the magnetic pole detected by the magnetic sensor 2b changes due to the rotation of the motor 1, and the output signal of the rotation pulse generator 2 is proportional to the rotation speed of the motor 1. It becomes a pulse signal c of a frequency. The rising edge of the pulse signal c is detected by the edge detection circuit 3 and becomes the edge detection signal d. The period measurement counter 4 counts clock pulses of a predetermined period generated therein, and is a valid level of the edge detection signal d.
When the H 'level pulse signal is input, the count value is transferred to the period data register 5, and the counter is cleared at the same time. Therefore, the data in the cycle data register 5 is the latest data obtained by measuring the cycle between the rising edges of the rotation pulse signal c. The CPU 6 reads the data of the period data register 5 and calculates the speed by performing a reciprocal operation of the data.

[0009]

In such a conventional configuration, the waveform of the output signal c of the rotation pulse generator 2 is the same regardless of whether the rotation direction of the motor 1 is normal or reverse. Only the absolute value of the speed could be detected, and the direction of rotation could not be detected. When the motor 1 is rotating at a low speed, the signal output from the magnetic sensor 2b is a signal that changes with a gentle slope with respect to time. Chattering may occur at points. At this time, since a very short pulse period due to the chattering is measured, a large error occurs. Further, since the cycle of performing the speed detection is the same as the cycle of the rotation pulse signal c and depends on the speed, the speed detection cycle becomes longer in proportion to the reciprocal of the speed as the motor 1 rotates at a low speed. turn into. For this reason, at the time of low-speed rotation, the speed detection period becomes extremely long, and there is a problem that it is difficult to detect a change in speed.

The present invention solves the above-mentioned conventional problems. The rotation direction of the motor 1 can be detected. Even if chattering occurs in the rotation pulse signal c when the motor 1 is rotating at a low speed, the detection error is not detected. Another object of the present invention is to provide a speed detecting device capable of detecting a speed change at the time of low-speed rotation earlier.

[0011]

SUMMARY OF THE INVENTION In order to achieve the above object, a speed detecting apparatus according to the present invention is firstly mounted on a motor, having a frequency proportional to the rotation speed of the motor, and having a frequency of 90 degrees with respect to each other. A rotation pulse generator that outputs a pulse signal of an A-phase signal and a B-phase signal having a phase difference, an edge detection circuit that detects a rising edge or a falling edge of one of the A-phase signal and the B-phase signal, A cycle measurement counter that measures the cycle of the output signal of the edge detection circuit, and receives an output pulse signal of the rotation pulse generator,
By detecting the level of the B-phase signal at the timing of both rising and falling edges of the A-phase signal, and detecting the level of the A-phase signal at the timing of both rising and falling edges of the B-phase signal, A quadruple circuit that outputs a count pulse signal or a downcount pulse signal, and an upcount pulse signal of the quadruple circuit counts up.
An up / down counter that counts down, detects a speed based on the count value of the cycle measurement counter, or the count value of the up / down counter, and the detected speed is in a region near zero speed and zero speed. In this case, the next speed detection is performed based on the count value of the up / down counter, and in other cases, the next speed detection is performed based on the count value of the cycle measurement counter.

Second, in the first speed detecting device, the speed at which the speed is switched from the speed detection based on the count value of the period measurement counter to the speed detection based on the count value of the up / down counter, and the count value of the up / down counter Is different from the speed of switching from speed detection based on the speed detection to speed detection based on the count value of the period measurement counter.

Third, in the first or second speed detecting device, switching between speed detection based on the count value of the up / down counter and speed detection based on the count value of the cycle measurement counter is performed by an up / down counter. Is performed at a detection speed at which the count value is a multiple of four.

Thus, the rotation direction of the motor can be detected. Even if chattering occurs in the rotation pulse signal c when the motor is rotating at a low speed, this does not become a detection error.
Further, it is possible to realize a speed detecting device capable of quickly detecting a speed change at the time of low-speed rotation.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention has a frequency proportional to the number of revolutions of a speed detection target, and
A rotating pulse generator for outputting a pulse signal of an A-phase signal and a B-phase signal having a phase difference of 90 degrees from each other;
An edge detection circuit that detects a rising edge or a falling edge of one of the phase signals, a cycle measurement counter that measures a cycle of an output signal of the edge detection circuit, and an output pulse signal of the rotation pulse generator. The rising edge of the A-phase signal when the B-phase signal is “L” and the rising edge when the A-phase signal is “H”
The rising edge of the B-phase signal and the B-phase signal
When the falling edge of the A-phase signal when H is detected and the falling edge of the B-phase signal when the A-phase signal is L are detected, an up-count pulse signal is output and the B-phase signal is output. The rising edge of the A-phase signal when A is “H”, the falling edge of the B-phase signal when the A-phase signal is “H”, and the A when the B-phase signal is “L”. Falling edge of phase signal,
And a quadruple circuit that outputs a down-count pulse signal when a rising edge of the B-phase signal is detected when the A-phase signal is “L”, and counts up with the up-count pulse signal of the quadruple circuit. An up-down counter that counts down with a down-count pulse signal, and detects a speed based on the count value of the period measurement counter or the count value of the up-down counter, and the detected speed is zero speed and zero speed. When it is in the vicinity area, the next speed detection is performed based on the count value of the up-down counter, otherwise, the next speed detection is performed based on the count value of the cycle measurement counter. With this configuration, when the speed detection target is rotating at low speed, the up-down counter When the speed detection based on the count value is used, the direction of increase / decrease of the count value changes depending on the rotation direction, so that information on the rotation direction can be obtained, and the influence of the mixing of the erroneous pulse signal with a very short cycle is canceled. In addition, the speed detection cycle does not depend on the speed.

According to a second aspect of the present invention, in the speed detecting device according to the first aspect, the speed is switched from the speed detection based on the count value of the period measurement counter to the speed detection based on the count value of the up / down counter; The speed is switched from the speed detection based on the count value of the up / down counter to the speed detection based on the count value of the cycle measurement counter. Switching between the detected speed and the speed detection based on the count value of the up / down counter can be performed smoothly.

According to the third and fourth aspects of the present invention,
In the speed detection device according to claim 1 or 2, switching between speed detection based on the count value of the up / down counter and speed detection based on the count value of the cycle measurement counter is performed when the count value of the up / down counter is four. This is a configuration that performs detection at multiple speeds, so that when switching speed detection, the accuracy of the detection speed based on the count value of the up-down counter is the highest, and the change in detection speed due to switching is reduced. It is possible to do.

An embodiment of the present invention will be described below with reference to FIGS. (Embodiment 1) An embodiment of the present invention will be described below with reference to FIG.

In FIG. 1, a rotation pulse generator 8 outputs two rotation pulse signals of an A-phase signal a and a B-phase signal b having a frequency proportional to the rotation speed of the motor 1. The B-phase signals b have a phase difference of 90 degrees from each other.

The edge detection circuit 3 receives the A-phase signal a and outputs an edge detection signal e upon detecting a rising edge thereof.

The period measurement counter 4 outputs an edge detection signal e
And its period is measured. The configurations of the edge detection circuit 3 and the cycle measurement counter 4 are the same as those of the conventional example. The quadrupling circuit 9 receives two rotation pulse signals of the A-phase signal a and the B-phase signal b from the rotation pulse generator 8 and
The level of the B-phase signal is detected at the timing of both the rising and falling edges of the phase signal, and the level of the A-phase signal is detected at the timing of both the rising and falling edges of the B-phase signal. When the B-phase signal detected at the rising edge is “L” level,
A phase signal detected at the rising edge of the phase signal is
When the H-level, and the B-phase signal detected at the falling edge of the A-phase signal is at the “H” level, and when the A-phase signal detected at the falling edge of the B-phase signal is “L”, When the signal is at the level, an up-count pulse signal f is output, and B is detected at the rising edge of the A-phase signal.
When the phase signal is at the "H" level, and when the A-phase signal detected at the falling edge of the B-phase signal is at the "H" level, and at the B-phase signal detected at the falling edge of the A-phase signal Is "L" level, and the A-phase signal detected at the rising edge of the B-phase signal is "L".
When the signal is at the level, a down count pulse signal g is output.

The up-down counter 10 receives the up-count pulse signal f from the quadruple circuit 9,
It counts up and counts down when the down count pulse signal g is input.

The CPU 6 stores data of the cycle measurement counter 4,
Alternatively, the speed is calculated based on the data of the up / down counter 10, and the cycle measurement counter 4 and the up / down counter 10 are connected via the data bus 7.

FIG. 3 shows a specific configuration example of the rotation pulse generator 8. In FIG. 3, the ring-shaped magnet 8a is fixed to the rotating shaft of the motor 1,
It rotates at the same speed as. The magnetic sensors 8b and 8c are fixed to the frame of the motor 1,
In order to detect the magnetism of the ring-shaped magnet 8a, the ring-shaped magnet 8a and the ring-shaped magnet 8a are kept apart from each other by a certain amount.
It is arranged at a position perpendicular to the rotation axis so as to have a phase relationship of degrees. The output signals of the magnetic sensors 8b and 8c are formed into a pulse waveform via a waveform processing circuit (not shown), and are configured to be rotation pulse signals of the A-phase signal a and the B-phase signal b, respectively.

The operation of the above configuration will be described. FIG. 4 is a time chart showing signal waveforms of various parts when the motor 1 is rotating. FIG. 4A shows the motor 1
Is rotating in the direction h1 in FIG.
Is when the motor 1 is rotating in the direction h2 in FIG.

Since the ring-shaped magnet 8a is fixed to the rotating shaft of the motor 1, the magnetic poles detected by the magnetic sensors 8b and 8c change as the motor 1 rotates, and the A-phase signals a and
The waveform of the B-phase signal b is a pulse signal having a frequency proportional to the speed of the motor 1 and having a phase difference of 90 degrees from each other.

The quadruple circuit 9 receiving the input of the pulse signals a and b outputs the rising and falling edges of the A-phase signal and the rising and falling edges of the B-phase signal at the same timing. As described above, the up count pulse signal f or the down count pulse signal g is output.

The up / down counter 10 counts up by inputting an "H" level pulse signal which is an effective level of the up count pulse signal f, and inputs an "H" level pulse signal which is an effective level of the down count pulse signal g. To count down. Then, the count value is transferred to the internal pulse count register 11 at every predetermined fixed sampling time, and the counter is cleared at the same time. Therefore, the data of the pulse count register 11 indicates the number of input pulses for each fixed sampling time.

In the edge detection circuit 3, the A-phase signal a
Is detected as an edge detection signal e.

The period measurement counter 4 counts clock pulses of a predetermined period generated therein, and when an "H" level pulse signal, which is an effective level of the edge detection signal e, is input, the count value is stored in the period data register. 5 and clear the counter at the same time. Therefore, the data in the cycle data register 5 is the latest data obtained by measuring the cycle between the rising edges of the A-phase signal a.

In the CPU 6, the pulse count register 1
1 or the cycle data register 5
The speed is calculated based on the reciprocal of the data read.

Here, whether to use the value of the pulse count register 11 or the value of the cycle data register 5 is determined based on the previous detection speed. As shown in FIG. If the value is close to the set zero speed, the data of the pulse count register 11 is used.
The speed is detected using the data of. This switching speed V
1 and V2 have no practical problem in the detection period of the period measurement,
In addition, the speed is set as low as possible without causing chattering problems. For example, several 10 to several 100 r / min
It is set to a value of about.

Here, the up / down counter will be described in detail. As shown in FIGS. 4 (a) and 4 (b), the increase / decrease of the value of the up / down counter is switched according to the rotation direction of the motor 1. The rotation direction of the motor can be determined from the sign of the value of the down counter.
Also, as shown in FIG. 5, when the motor is rotating at a low speed, even if chattering occurs in the pulse signals of the A-phase signal a and the B-phase signal b, the count of very short pulses due to the chattering is canceled out. This is not a detection error. Further, as for the period for performing the speed detection, the data of the pulse count register 11 is rewritten every fixed sampling time of the up / down counter 10, so that the speed of the motor 1 is not dependent on the speed of the motor 1 even at low speed rotation. It is possible to quickly follow the speed change.

As described above, according to this embodiment, the rotation direction of the motor can be detected by detecting the speed based on the count value of the up / down counter 10 in the zero speed and the area near the zero speed. When the motor is rotating at a low speed, even if chattering occurs in the rotation pulse signal, this does not become a detection error, and the up / down counter 10 updates data used for speed detection at regular sampling times. Therefore, the speed detection cycle does not depend on the speed, and a speed detection device that can quickly detect a change in speed during low-speed rotation can be realized.

(Embodiment 2) Hereinafter, a second embodiment of the present invention will be described with reference to the drawings.

FIG. 6 shows the switching speed of the speed detection in this embodiment. V3 and V4 denote the speed detection based on the count value of the period measurement counter 4 and the speed detection based on the count value of the up / down counter 10. V5 and V6 are second switching speeds for switching from speed detection based on the count value of the up / down counter 10 to speed detection based on the count value of the cycle measurement counter 4. That is, in the speed detection device described in the first embodiment, the speed at which the speed is switched from the speed detection based on the count value of the period measurement counter 4 to the speed detection based on the count value of the up / down counter 10 and the count of the up / down counter 10 The speed is switched from the speed detection based on the value to the speed detection based on the count value of the cycle measurement counter 4 and has a difference.

In the configuration of the first embodiment, the two speeds V1 and V2 at which the speed detection by the up / down counter 10 and the speed detection by the cycle measurement counter 4 are switched due to an error in the speed detection. In some cases, the mutual switching of the speed detection is repeatedly performed for a while. In order to avoid this problem, the configuration of the present embodiment is adopted.

Even if the motor 1 is rotating at a constant speed, a counting error of one count pulse occurs depending on the sampling timing, so that the detection speed is not constant and varies. Speeds V1 and V for switching speed detection
At a low speed such as 2, the detection error is small in the cycle measurement counter 4 because the count pulse cycle is sufficiently short with respect to the sampling cycle, but the number of count pulses is small in the up-down counter 10, so the count pulse The period is large, that is, the weight of one count pulse is large, and the detection error is large. For this reason, for example, when the speed detection is switched from the up / down counter 10 to the period measurement counter 4, even if the actual speed of the motor 1 does not change, the detection speed may be reduced. The phenomenon that the speed detection is returned to 10 occurs. Conversely, when the speed detection is switched from the cycle measurement counter 4 to the up / down counter 10, the detection speed may increase, and at this time, the speed detection is returned to the cycle measurement counter 4.

In order to prevent such a phenomenon from occurring, in the present embodiment, the difference between the first switching speed V4 and the second switching speed V6 is set to the first switching speed V3 and the second switching speed V5. Up-down counter 1
It is set to be equal to or greater than the difference between the maximum value of the variation range of the detection speed at 0 and the minimum value of the variation range of the detection speed in the cycle measurement counter 4.

With this configuration, even when the speed of detection is switched from the up / down counter 10 to the period measurement counter 4 and the detection speed is reduced, the speed of switching from the period measurement counter 4 to the up / down counter 10 is lower than that. Since this is set, the problem that the speed detection returns to the original up / down counter 10 is eliminated. Also,
Even when the speed detection is switched from the period measurement counter 4 to the up / down counter 10, the speed detection does not return to the original state because the detected speed does not exceed the speed at which the up / down counter 10 switches to the period measurement counter 4.

As described above, according to the present embodiment, switching from speed detection based on the count value of the cycle measurement counter 4 to speed detection based on the count value of the up / down counter 10 and switching of the up / down counter 10 Switching from speed detection based on the count value to speed detection based on the count value of the period measurement counter 4 is performed at another point, and is not affected by a change in the detected speed before and after the speed detection is switched. In addition, it is possible to suppress fluttering of switching of speed detection due to a difference in detection speed between the use of the period measurement counter and the use of the up / down counter in the switching speed.

(Embodiment 3) Hereinafter, a third embodiment of the present invention will be described.

In this embodiment, the difference from the speed detecting devices shown in the first and second embodiments is that
Switching between speed detection based on the count value of the up / down counter 10 and speed detection based on the count value of the cycle measurement counter 4 is performed at a detection speed at which the count value of the up / down counter 10 is a multiple of four. That is the point.

As described above, the first embodiment and the second embodiment
In the speed detecting device according to the embodiment, in the two pulse signals of the A-phase signal a and the B-phase signal b output from the rotation pulse generator 8, the phase difference between the respective edges is not necessarily 90 degrees. It is not necessarily. Here, FIG.
(a) shows the positional relationship between the ring-shaped magnet 8a and the magnetic sensors 8b and 8c inside the rotation pulse generator 8 when the rotation axis of the motor 1 is viewed from the front. Originally, the ring-shaped magnet 8a is magnetized to the north and south poles so as to have an angle of 180 degrees. Also, the magnetic sensor 8
b and 8c are arranged so as to have a phase relationship of 90 degrees with each other. However, the angle θ1 of the magnetic sensors 8b and 8c with respect to the rotation axis deviates from 90 degrees due to the magnetic sensor mounting accuracy, and the angle θ2 of the N pole of the ring-shaped magnet 8a also deviates from 180 degrees due to the magnetization accuracy. Have. The characteristics of the magnetic sensors 8b and 8c also vary. Due to the influence of these errors, FIG.
As shown in (b), even if the motor 1 is rotating at a constant speed, the time between each edge of the rotation pulse signal of the A-phase signal a and the B-phase signal b formed from the output signal of the magnetic sensor. T1, T2, T3, and T4 do not have the same value. Therefore, the error of the up-down counter 10 described in the second embodiment becomes even larger, and the difference between the first switching speed and the second switching speed must be set to be large in consideration of this.

However, the sum T4 of T1, T2, T3, and T4 is the cycle of the output signal of one sensor, so that the error due to the above-described factors does not occur, and the motor rotates at a constant speed. , T5 is always constant. Therefore, from a different point of view, the error becomes the smallest when counting a multiple of 4 edges at regular intervals. That is, when speed detection is performed based on the count value of the up-down counter 10, the accuracy of the detection speed is highest when the output count value is a multiple of four.

In this embodiment, the speed detection is switched at a detection speed at which the count value of the up / down counter 10 is a multiple of 4 in order to reduce the influence of the error when switching the speed detection. Thereby, since the error in the detection speed by the up / down counter 10 at the time of switching is minimized, the amount of change in the detection speed before and after switching can be reduced.

As described above, according to the present embodiment, the speed detection switching speed is set to the detection speed at which the output count value is a multiple of 4 with the highest accuracy in the up / down counter 10, and the speed detection is performed. It is possible to reduce the amount of change in the detection speed before and after the switching, and accordingly, the first switching speed and the second switching speed shown in the second embodiment can be reduced.
Can be reduced.

[0048]

As described above, according to the present invention, first, the rotary pulse generator generates a two-phase pulse signal having a frequency proportional to the rotation speed of the speed detection target and having a phase difference of 90 degrees from each other. Output, and in addition to the period measurement counter, 4
Using an up / down counter that receives and counts the output from the multiplier circuit, when the detected speed is in the region near zero speed and zero speed, the next speed detection is performed based on the count value of the up / down counter, The time is based on the count value of the period measurement counter, so that the rotation direction of the speed detection target can be detected.When the speed detection target is rotating at low speed, chattering occurs in the rotation pulse signal. This does not become a detection error, and it is possible to provide a speed detecting device that can accurately detect the speed and can quickly follow the speed change at a low rotation speed. .

Second, in the first speed detecting device, the speed at which the speed is switched from the speed detection based on the count value of the period measurement counter to the speed detection based on the count value of the up / down counter, and the count value of the up / down counter Has a difference from the speed at which the speed detection is switched based on the speed detection based on the count value of the cycle measurement counter to the speed detection method, so that the speed detection method can be smoothly switched. An object of the present invention is to provide a speed detection device capable of suppressing fluttering of switching of speed detection, which is caused by a difference in detection speed between time and use of an up / down counter.

Third, in the first or second speed detecting device, switching between speed detection based on the count value of the up / down counter and speed detection based on the count of the period measurement counter is performed by an up / down counter. Is performed at a detection speed at which the count value is a multiple of four, the speed detection is switched at a point where the up-down counter can detect the speed with the highest accuracy, and the detection speed before and after the speed detection is switched. The change can be reduced, and the difference between the switching speeds of the speed detection in the second speed detection device can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram of a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of speed detection switching in the first embodiment.

FIG. 3 is a configuration diagram of a rotation pulse generator.

4A is a diagram illustrating the operation of FIG. 1 when the motor 1 rotates in a direction h1. FIG. 4B is a diagram illustrating the operation illustrated in FIG. 1 when the motor 1 rotates in a direction h2.

FIG. 5 is an explanatory diagram of chattering in a rotation pulse signal.

FIG. 6 is an explanatory diagram of switching of speed detection according to the second embodiment of the present invention.

FIG. 7A is an explanatory diagram of an internal configuration of a rotation pulse generator. FIG. 7B is an explanatory diagram of a phase difference error of a rotation pulse signal.

FIG. 8 is a block diagram of a conventional speed detection device.

FIG. 9 is a configuration diagram of a rotation pulse generator.

FIG. 10 is a diagram illustrating the operation of a conventional speed detection device.

[Explanation of symbols]

 Reference Signs List 1 motor 3 edge detection circuit 4 cycle measurement counter 5 cycle data register 6 central processing unit (CPU) 7 data bus 8 rotation pulse generator 9 quadruple circuit 10 up / down counter 11 pulse count register a A-phase signal b B-phase signal e Edge detection signal f Up count pulse signal g Down count pulse signal

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01P 3/489 G01P 13/04 H02P 5/00

Claims (5)

(57) [Claims] An A-phase signal and a B-phase signal having a frequency proportional to the rotation speed of a speed detection target and having a phase difference of 90 degrees from each other.
A rotation pulse generator that outputs a pulse signal of a phase signal, an edge detection circuit that detects a rising edge or a falling edge of one of the A-phase signal and the B-phase signal, and an output signal of the edge detection circuit. A period measurement counter for measuring the period; receiving the output pulse signal of the rotary pulse generator; a rising edge of the A-phase signal when the B-phase signal is “L”; The rising edge of the B-phase signal at a certain time, the falling edge of the A-phase signal when the B-phase signal is 'H', and the falling edge of the B-phase signal when the A-phase signal is 'L' When an edge is detected, an up-count pulse signal is output. The rising edge of the A-phase signal when the B-phase signal is 'H' and the rising edge of the B-phase signal when the A-phase signal is 'H' Falling edge When the falling edge of the A-phase signal when the B-phase signal is “L” and the rising edge of the B-phase signal when the A-phase signal is “L” are detected, the down-count pulse signal is generated. A quadruple circuit that outputs the signal; and an up / down counter that counts up with an up count pulse signal of the quadruple circuit and counts down with a down count pulse signal. Speed is detected based on the count value of
If the detected speed is in the zero speed or in the area near the zero speed, the next speed detection is performed based on the count value of the up / down counter, otherwise, the next speed detection is performed by the period measurement counter. A speed detection device characterized in that the speed detection is performed based on a value. 2. An A-phase signal and a B-phase signal having a frequency proportional to the rotation speed of the speed detection target and having a phase difference of 90 degrees from each other.
A rotation pulse generator that outputs a pulse signal of a phase signal, an edge detection circuit that detects a rising edge or a falling edge of one of the A-phase signal and the B-phase signal, and an output signal of the edge detection circuit. A period measurement counter for measuring the period; receiving the output pulse signal of the rotary pulse generator; a rising edge of the A-phase signal when the B-phase signal is “L”; The rising edge of the B-phase signal at a certain time, the falling edge of the A-phase signal when the B-phase signal is 'H', and the falling edge of the B-phase signal when the A-phase signal is 'L' When an edge is detected, an up-count pulse signal is output. The rising edge of the A-phase signal when the B-phase signal is 'H' and the rising edge of the B-phase signal when the A-phase signal is 'H' Falling edge When the falling edge of the A-phase signal when the B-phase signal is 'L' and the rising edge of the B-phase signal when the A-phase signal is 'L' are detected, the down-count pulse signal is generated. A quadruple circuit that outputs the signal; and an up / down counter that counts up with an up count pulse signal of the quadruple circuit and counts down with a down count pulse signal. The count value of the period measurement counter or the up / down counter Speed is detected based on the count value of
If the detected speed is in the zero speed or in the area near the zero speed, the next speed detection is performed based on the count value of the up / down counter. Otherwise, the next speed detection is performed by the period measurement counter. Based on the value, the speed is switched from the speed detection based on the count value of the cycle measurement counter to the speed detection based on the count value of the up / down counter, and the speed measurement is counted from the speed detection based on the count value of the up / down counter and counted by the cycle measurement counter A speed detection device characterized in that it has a configuration different from the speed at which the speed is switched to speed detection based on a value. 3. An A-phase signal and a B-phase signal having a frequency proportional to the rotational speed of the speed detection target and having a phase difference of 90 degrees from each other.
A rotation pulse generator that outputs a pulse signal of a phase signal, an edge detection circuit that detects a rising edge or a falling edge of one of the A-phase signal and the B-phase signal, and an output signal of the edge detection circuit. A period measurement counter for measuring the period; receiving the output pulse signal of the rotary pulse generator; a rising edge of the A-phase signal when the B-phase signal is “L”; The rising edge of the B-phase signal at a certain time, the falling edge of the A-phase signal when the B-phase signal is 'H', and the falling edge of the B-phase signal when the A-phase signal is 'L' When an edge is detected, an up-count pulse signal is output. The rising edge of the A-phase signal when the B-phase signal is 'H' and the rising edge of the B-phase signal when the A-phase signal is 'H' Falling edge When the falling edge of the A-phase signal when the B-phase signal is 'L' and the rising edge of the B-phase signal when the A-phase signal is 'L' are detected, the down-count pulse signal is generated. A quadruple circuit that outputs the signal; and an up / down counter that counts up with an up count pulse signal of the quadruple circuit and counts down with a down count pulse signal. The count value of the period measurement counter or the up / down counter Speed is detected based on the count value of
If the detected speed is in the zero speed or in the area near the zero speed, the next speed detection is performed based on the count value of the up / down counter. Otherwise, the next speed detection is performed by the period measurement counter. The switching between the speed detection based on the count value of the up / down counter and the speed detection based on the count value of the period measurement counter is performed at a detection speed at which the count value of the up / down counter is a multiple of four. A speed detecting device characterized in that: 4. Switching between speed detection based on the count value of the up / down counter and speed detection based on the count value of the period measurement counter is performed at a detection speed at which the count value of the up / down counter is a multiple of four, The speed that switches from speed detection based on the count value of the cycle measurement counter to speed detection based on the count value of the up / down counter, and speed based on the count value of the cycle measurement counter from speed detection based on the count value of the up / down counter 2. The speed detecting device according to claim 1, wherein a speed is different from a speed at which the speed is switched to detection. 5. The detected speed is zero speed and zero speed.
Preset the next speed detection when in the nearby area
Up / down count at a fixed sampling time
Data and the sampling time.
2. The speed detecting device according to claim 1, wherein the speed is detected.