JPS60131097A - Rotation detector of stepping motor - Google Patents

Abstract

PURPOSE:To effectively detect the rotation of a stepping motor and to reduce the cost by detecting the rotation by providing a detecting winding on a stator. CONSTITUTION:A detecting winding 6 is wound to wound an exciting main winding 10. Whether the rotor 5a of a permanent magnet type stepping motor is rotated or not is detected by the winding 6. The voltage waveform C of the winding 6 is integrated by an integrator 7. The output waveform D of the integrator 7 is high when a rotor is normally rotated, and becomes low value when rotated erroneously. Accordingly, when this is compared by a voltage comparator 8, the pulse output E is outputted only when the rotor normally rotates.

Description

DETAILED DESCRIPTION OF THE INVENTION With the increasing use of microcomputers in various industrial applications, stepping motors are also being used extensively. %v
It is widely used in automotive applications in the field of ``I'' controllers.

The present invention relates to a stepping motor that can be used in any of these fields.

Conventional Structure and Problems A stepping motor is a motor that moves at a fixed angle or a fixed distance in response to an input signal.

Therefore, the positioning of the controlled object can be performed by open loop control. This is the greatest feature of stepping motors, and by issuing control pulses with an arbitrary number of steps using a microprocessor, it is possible to position the object to be controlled without any feedback from the motor, which is why microprocessors have become rapidly popular. At the same time, stepping motors are also being used in large quantities.

As mentioned above, the greatest feature of stepping motors is that positioning can be controlled using open-loop control, but on the other hand, since there is no feed bank, if a malfunction occurs even once, all subsequent positioning will be caused by this malfunction. I'm too lazy to accept something that contains errors. Conventionally, as a method to improve this point, a method has been used in which an optical encoder is incorporated into the motor and feedback of the child position is applied. This is shown in FIG. According to this method, a slit 2 is provided in the disc 1 of the encoder at a position where the output is output at the same position as the rest position of the rotor or with a certain deviation, and the slit 2 is connected to the light emitting element 3 and the light receiving element 4. detection L,
The rotor position of the stepping motor 5 is detected. With this method, it is possible to detect a position in one-to-one correspondence with each static position of the rotor, so it is an extremely reliable position detection method. However, as shown in FIG. 2(a), the motion of the rotor of a stepping motor is generally such that the overshoot is less than 9, and in this case, the above-mentioned light receiving element 4 has a pulse example corresponding to this. Figure 2 (b
) appears as shown. In order to use this as a normal position detection pulse, it is necessary to have a function that removes a set of forward and reverse pulses as they are not valid position signals, and for this purpose it is necessary to install two sets of light emitting and light receiving elements. It is necessary to distinguish between forward and reverse, and a logic circuit to process this. Therefore, it is necessary to attach a detection disk and determine the position of the slit 2 provided therein and the resting position of the rotor, and it is also necessary to add the above-mentioned functions, which is a disadvantageous method in terms of cost. There is.

Purpose of the Invention The present invention solves the above-mentioned conventional problems, and detects malfunctions of the rotor and performs positioning without installing a detector outside the motor and with a simple circuit for signal processing. The object of the present invention is to provide a rotation detection device for a stepping motor that improves control reliability.

Structure of the Invention The present invention includes a detection winding, an integration circuit, and a voltage or current comparison circuit provided on the stator of a permanent magnet stepping motor. Description of Embodiment 0, Which Can Perform Positioning Control Next, an embodiment of the present invention will be described based on an embodiment of the present invention and FIG. 3. In FIG. 3, 51L is a rotor of a permanent magnet type stepping motor, which has a permanent magnet as a component. 6 is the stepping motor V (a detection winding provided therein), 7 is an integrating circuit, and 8 is a voltage comparison circuit 111.

FIG. 4 shows an embodiment of the detection winding 6. In Figure 4,
Reference numeral 9 denotes a winding frame for winding the excitation main winding 10, around which the detection winding 6 is also wound. This detection winding 6 is implemented in a permanent magnet type stepping motor of the type shown in FIG. 5, and in FIG. 5a is a permanent magnet portion of the rotor. Also, 12 is the rotor shaft, 132L, 1
3b and 14, 14b is a yoke, 16 is a mounting plate, 16 is a bearing fixing plate, and 17a and 1 are bearing metals.

The operation of this embodiment configured as above will be described below. FIG. 6 shows the valley voltage waveform in this example. When the detection winding 6 is provided on the stator winding 11a side, if the excitation pulse shown in FIG. 6A is applied to the identifier winding 112L and Bi is applied to the stator winding 11b, the rotor will rotate normally. When the voltage waveform shown in C is generated in the detection winding 6, this voltage waveform Cv? - is the voltage C1 due to the transient phenomenon that occurs at the rise of the excitation pulse along with the sinusoidal fundamental wave generated by the power generation of the permanent magnet 6 & included in the rotor.
and the voltage C2 generated at the falling edge of the same pulse.

These voltages C1 and 02 are generated regardless of the rotation of the rotor, but the peak value of the sinusoidal fundamental wave changes when the rotor does not rotate normally.

Malfunctions of normal stepping motors occur when the rotor cannot rotate due to overload, resonance, etc., so the peak value of the sine wave decreases.

Therefore, if the voltage waveform of the detection winding Cf is integrated by the integrator circuit 7, the output waveform of the integrator circuit 7, indicated by D, will be high when the rotor is rotating normally; The value is low when 111 is being produced. Therefore, by comparing this with the voltage f, lE J by the comparison circuit 8, it is possible to output a pulse output Ei only when the rotor moves normally. If the malfunction detection signal output Ei is read by a microprocessor or the like, it can be determined whether the stepping motor is rotating normally. If a malfunction is detected, the influence of this malfunction can be removed by resetting the positioning. As a method of resetting, it is sufficient to provide a mechanical stopper to the kl ni ak jlil + device and supply sufficient pulses to the stepping motor to reach the value V (kl ni ak jlil +).

The method for determining whether the rotation is normal is to create a signal F that goes high when the output signal E of the voltage comparison circuit 8 rises and goes low when the excitation pulse B falls. If it is determined whether the signal F is a Bein Bell immediately before the rising edge, it is possible to detect a malfunction of the stepping motor.

Alternatively, it may be determined whether the signal E is at a high level immediately before the excitation pulse A rises.

In addition, in order to avoid the complexity of microprocessor programming, if you want to always check signal E immediately before switching each excitation pulse (14.15), when signal E is low level four or more times in a row, It may be determined that a malfunction has occurred. If the voltage comparator circuit 8 in FIG. 3 has a hysteresis characteristic so that the signal E remains at a high level for one hour even after the excitation pulse A rises in FIG. increases.

In this practical example, 7 in FIG. 3 is an integrating circuit, but it may also be a low-pass filter. In this embodiment, the detection winding 6 is provided only in the stator winding 11a shown in FIG. 5, but the detection winding 6 is also provided in the stator winding 16 in the same way as for the signal E in FIG. There is no doubt that if this signal is used together with signal E to detect malfunctions, the reliability of malfunction detection will be further increased.

Effects of the Invention By providing a detection winding on the stator, the present invention can detect rotation without using a light-year encoder or Hall element, and this winding can be made with only a few tens of turns at most. Since the A and J bows can be taken out sufficiently, it can be manufactured at low cost. In addition, rotational abnormalities can be easily detected by the integration circuit and voltage comparison circuit that are combined with this, and with the recent development of ICs, operational amplifiers and the like can be obtained at low cost for this circuit, so the rotation of the stepping motor can be detected by the above combination. It is something that can be done reliably and inexpensively.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing a conventional rotation detection device for a stepping motor, FIG. 2 is an explanatory diagram of the operation of the same motor, and FIG. 3 is a circuit diagram of a rotation detection device for a stepping motor according to the present invention.
FIG. 4 is a partially cutaway perspective view of a detection winding used in the apparatus, FIG. 5 is an exploded perspective view of the stamping motor, and FIG. 6 is an output waveform diagram of each part. 5a...Permanent magnet (rotor), 6...Detection winding, A...Integrator circuit, 8...Voltage comparison circuit, 11a. 11b...Stator winding. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure Ca) (b) Time Figure 3 Figure 4 Figure 5 Section 66

Claims (1)

[Scope of Claims] A stepping motor having a permanent magnet in a stator or a rotor, a main winding provided on the stator, and a rotation detection winding provided separately from the main winding; A step consisting of an integrating circuit connected to a detection winding, and a voltage comparison circuit or current comparison circuit connected to this integration circuit and outputting a malfunction detection signal. Temping motor rotation detection device.