JPS59174763A - Detecting device of revolution speed and position of rotating body - Google Patents

Abstract

PURPOSE:To detect an abnormal condition on the speed detector side and allow a controlling apparatus to process and respond without inflicting any load on the controlling apparatus side, by adding a self-diagonizing function representing a 3-state parformance of a line-driver output in a revolution speed and position detecting sensor itself. CONSTITUTION:In case when a pulse input is in a normal condition, output of an exclusive OR circuits 38, 39 are delivered on an H-level. However, in case when, as shown in Fig. (a), an input pulse of B-phase remains on the H-level (or on an L- level), outputs of fliq-flops 31 and 32 become identical and the output of the exclusive OR circuit becomes located on the L-level. In case of condition shown in Fig. C, while a pulse of Z-phase is on the H-level., an output of an OR circuit 42 is not located on the L-level, and even if a pulse in a Z-phase is on the L- level, as the output of flip-flop is not subject to resetting, the L-level stays and an output of OR circuit 40 is located on the L-level also. As shown Fig. (d), when the Z-phase remains on the ''L'' level, an abnormality is detected from the OR circuit 46, negation OR circuit 41 with flip-flops 36, 37.

Description

[Detailed Description of the Invention] [H4 Field of Benefits of the Invention] The present invention relates to the speed and position detector of a rotating body, more specifically, to the speed of a servo system, the position tlj-detector and the +=J speed of a rotating body. This invention relates to a speed and position detection device equipped with an abnormality detection function and used as an interface with a first generation control device.

"Prior art" The speed of the AC servo system, the speed of the position detector and the speed of the rotating body (electric motor), and the interface section of the position control device are controlled by differential lines (balanced transmission) to prevent noise. The differential line driver is interfaced with a differential line receiver on the speed and position control device side, or a photocoupler.This speed and position detection device becomes a current transmission path and detects pulses in the flow direction. Since current flows through the speed and position detectors except for breaks in the transmission line itself, it has been difficult for the control device to detect abnormalities in the speed and position detectors themselves other than breaks in the transmission line.In other words, Even though the transmission line is not disconnected in response to the speed command from the speed and position control device, if an abnormality occurs in the speed detector system and no pulse is output to the transmission line, the transmission line An incorrect current flows.As a result, the control device detects this as one pulse of filled pack pulse being applied, and the rotating body whose speed is controlled by the pulse application naturally receives the speed adjustment pulse that is properly applied. As the deviation from The machine tools, robots, etc. that were being used would not only cause abnormal movements, making highly reliable rotation control impossible, but also lead to major accidents in some cases.

On the other hand, the current circuit for detecting disconnection in the signal transmission system is not built into the rotation speed detector, but is provided on the speed control circuit side, so the protection circuit for the IQ1 rotation speed detector is In order to upgrade the performance, the software and hardware of the control device itself would have to be changed, which would be extremely time-consuming.

[Object of the Invention] The present invention has been made in view of the above-mentioned drawbacks of the prior art.
The present invention provides a highly reliable rotation speed and adhesion detection device that can detect an abnormal state on the speed detector side and notify a control device of the abnormal state.

rSummary of the Invention] The present invention is characterized in that a rotation detector includes a sensor that detects rotational speed, position, etc., a circuit that shapes the waveform of the sensor output, and a differential line driver. A detection circuit for abnormal output due to changes, etc. is provided, and the output on the rotation speed detector side is a three-state output including high impedance, and when an abnormality in the rotation speed or position detection sensor is detected, it becomes a high impedance output. Control device(
1'llll is judged as if it were disconnected, and is notified that there is an abnormality, and the process is then carried out.

[Embodiments of the Invention] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1st
The figure (!31 is a control block diagram of the rotation speed and position detection device, 11 is a rotation speed detection sensor of the same rotating body (not shown), 12.'13.14 is a minute voltage detected by the sensor 11. 15° 16.171d three-state differential line driver; 18 is a normality detection circuit provided at the output section of each waveform shaping circuit 12, 13, and 11;
19 is a speed control device for a rotating body (not shown).

According to the same circuit configuration, the minute /J\ voltage detected by the speed detection sensor 11 is
The signal is shaped into a logic level and transmitted as a feedback pulse to the speed control device by the three-state differential line driver 15, 16, 17. At this time, the abnormality detection circuit 18 constantly monitors the pulse state, and when an abnormality is detected, the differential line drivers 15, 16, and 17 are immediately set to high impedance and high power 12 to prevent malfunctions on the speed control device 19 side. control.

In such a rotational speed detection control system of a rotating body, for example, a TTL level A phase like the pulse wave in FIG.
It is assumed that the human phase, B phase, ■ phase, 2 phase, and 2 phase are transmitted to the speed control device 19. And the phase difference between phase A and phase B is ±90
The forward rotation or reverse rotation of the rotating body can be determined by the positive or negative phase difference. The speed control device side compares the number of pulses of this h@gate B phase as a feedback pulse with the speed command value, detects the deviation, and performs speed control.

Further, the two-phase pulse outputs one pulse per rotation of the rotating body, and is used for positioning No. 2 machine tools and the like.

Rotation speed detector 1 required for speed control as described above
The output pulse from W1 is the change in the detector W1 itself,
Pulses like those shown in Fig. 3 (a) to (d) may be output due to deterioration due to temperature changes, etc., but even in this case, the speed control device 19 has an output due to a disconnection of the transmission line. Unless the impedance becomes high, it will be difficult to detect abnormalities.

The present invention solves such problems, and the second
An abnormality detection circuit based on the circuit shown in the figure is shown in FIG. 4 and will be described. In Figure 4, A, B, and Z are A phase, B
@, Z-phase input signal terminal, 61 to 57 flip-flops, 38.39 are flip-flops 31.32 and 3
3. Exclusive OR circuit provided at the output section of 34, 40 is an OR circuit that receives the output of 7-lip 70-tube 35 and the 2-phase input signal, and the logical sum of the outputs of flip-flops 36 and 37 of 41. 42 is an exclusive OR circuit 38°3
9 and OR circuit/in, AND circuit that takes the AND of 41,
itaa3. aa is an inverter which inverts the A-phase and B-phase inputs and inputs them to the C terminal of the flip-flop 32.3A, 45. A6 takes the logical sum of the human phase and the B phase, and connects it to the reset terminal R of the 7 flip-flop 35 and the flip-flop 36.
．． It is input to the C terminal of 57.

First, as shown in the pulse waveform diagram of the Base 2 diagram, during normal times, the state of the B phase at the rise of the human phase and the rise of 1 phase is OV (hereinafter referred to as L level) and 5V (hereinafter referred to as H level), respectively. ). Now, in the circuit of Fig. 4, A
, If the pulse signal manually applied to the B phase is as shown in FIG.
The B-phase pulse is output as is. These signals are output by exclusive OR circuit 58 as rHJ level.

Similarly, when the B-phase pulse rises and the L-phase rises, A
The pulse state of the phase is outputted from the flip-flops 33 and 34, and similarly outputted by the exclusive OR circuit 69 as the rHJ level.

That is, when the pulse input is normal, the exclusive OR circuit 38.59 outputs the rHJ level. However, as shown in FIG.
In the case of J level 1 switch), the pulse states of A and B phase are the same at the rising edge of the A phase pulse, so the outputs of flip-flops 31 and 52 are the same, and the output of the exclusive OR circuit It becomes LJ level.

On the other hand, in the case shown in Figure 3(C), the above p
,, X, B, Since only the rising edge of the B-phase pulse disappears, the abnormality cannot be detected. Therefore, the flip-flop 35 and OR circuit dQ, , ! shown in FIG. l
+ detects an abnormality.

FIG. 2 shows the pulse waveform during normal operation, that is, Z.

The timing chart shows the logic OR of the pulse waveforms of the 2, A, and B phases.The output of the flip-flop 65 becomes rLJ due to the rise of the two phases, but the OR circuit 40 causes the pulse output of the two phases to become rLJ. The rHJ level is output as is, and the OR circuit A5 is based on the logical sum of the human phase and B phase.
The 7 lip-flop 35 is reset by the output of
The output becomes the rHJ level, the two phases become the rLJ level, and the output of the OR circuit 40 remains at the rHJ level.

However, in the case shown in FIG. 3(C), while the two-phase pulses are at the rHJ level, the output of the OR circuit 42 does not become low, and even when the z-phase pulse reaches the "L" level. rL because it takes less time to set the output of the flip 70 knob.
J remains, and the output of the OR circuit 40 also becomes rLJ.

In addition, as shown in FIG. 3 (di), when the two phases remain at the rLJ level, an abnormality is detected by the flip-flops 36 and 37 and the OR circuit 46 and negative OR circuit 41. When the sum rises, the two-phase output pulse state rHJ level is stored as is in the 7-lip flop 36.

If it is a normal two-phase pulse, at the rise of the next logical sum of A phase and B phase, [because it is at the level, OR is a negative logical sum.
The output of the circuit 41 is at the rHJ level, but as shown in FIG.
In a case like l, the output of the flip-flop 56.37 is at the rHJ level, so the output of the OR circuit A1 is rL.
It will be J level.

As mentioned above, under normal conditions, the A and ND circuits 420 are at the high level, but when an abnormality occurs, one or more of the four human forces will be at the rLJ level, so the output of the ANDICJ path 42 will be at the 2LJ level. . That is, the initial objective can be achieved by controlling the output of the differential line driver to high impedance during an abnormality using this signal.

According to this embodiment, an abnormal state of the detector that detects the rotational speed of the rotating body is immediately detected, and the output of the differential line driver that interfaces to the speed control device is set to high impedance. Since the speed control device can perform processing control as if it were a disconnection abnormality processing, it is possible to prevent accidents caused by erroneous control of the rotating body.

[Effects of the Invention] As is clear from the above description, according to the present invention, an abnormality detection function is added to the rotational speed and position detection device, so that the speed control device of the servo system as described above can be improved. It is possible to construct a highly reliable and highly safe system by lightening the load and quickly taking measures and processing responses to abnormalities.

[Brief explanation of drawings]

The attached drawings are diagrams for explaining the invention, and FIG. 1 is a control block diagram of the rotation speed and position detection device, and FIG. Timing chart of phase, two phases, and logical sum of A phase and B phase, Figure 3 shows A phase,
FIG. 4 is a timing chart illustrating the occurrence of an abnormality in phase B and phase 2, and FIG. 4 is a circuit diagram of an abnormality detection circuit section showing an embodiment of the invention. 11...Rotation speed detection sensor, 1:? , 13.44・
・Waveform shaping circuit, 15, 16.17... Retraction line driver, 18... Abnormality detection circuit, 19... Speed control DOL31-37... Flip-flop, 38.39
...exclusive OR circuit, 40. 711. A5. A6・
...OR circuit, 42...AND circuit 1 Closed Fig. 2

Claims (1)

[Claims] A rotation speed and position detection sensor that detects the rotation speed and position of the rotating body, a waveform shaping circuit that shapes the output waveform of the sensor, and a waveform shaping circuit are rarely installed to monitor abnormalities in the detected waveform and detect abnormalities. A rotational speed and position detection device comprising a driver circuit that feeds back to a speed control device of a rotating body that an abnormality has occurred in the circuit system if detected, and the rotational speed and adhesion detection sensor itself has a line. A device for detecting the rotational speed and position of a rotating body, which is characterized by the addition of a self-diagnosis device with a three-state driver output.