JPS62133358A - Discriminating device for rotational direction of motor - Google Patents

Abstract

PURPOSE:To decide the rotational direction of a motor invariably accurately by holding the rotational direction when the rotary speed of the motor reaches a specific speed as a rotating direction decision signal. CONSTITUTION:When the motor 1 rotates, a pulse P1 from a pulse generator 5 is passed through an F/V converter 9 and compared with a reference voltage Vr by comparators 13 and 15. The voltage Vr is set nearly equal to the output voltage of the converter 9 when the motor 1 begins to rotate, so the output voltage of the converter 9 rises above the voltage Vr and the output of the comparator 13 varies to a high level. Consequently, the leading signal of the output voltage of the comparator 13 is applied to the trigger input of an FF 11, which latches the low-level output of a D type FF 3 and outputs the same low-level signal from its output Q. This low-level output signal indicates the rotational direction of the motor 1 and is latched by the FF 11 at its leading and held latched until the motor 1 stops rotation, so the rotational direction is discriminated invariably accurately even if a noise is mixed in the pulse from the pulse.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a motor rotation direction determination device, and more particularly to a motor rotation direction determination LLI that determines the rotation direction of an induction motor used for a vehicle, for example.

[Technical background of the invention and its problems] Conventionally, DC type ei, which is easy to control, has been used as an electric motor for driving a vehicle, that is, an electric motor used in electric cars, etc.
Compared to DC motors, it has a simple structure and mounting, and there is no wear on brushes, etc., so it is maintenance free, small, lightweight, can be manufactured by a small number of people, and is highly efficient, meaning it can travel a long distance per charge. The use of AC Fas electric motors has come to be considered due to the fact that they have the characteristics of It has become.

By the way, in such a vehicle electric motor, various controls can be performed by determining its rotation direction.

FIG. 4 shows an example of a conventional motor rotation direction determining device using a flip-flop (Special Publication No. 120956/1983), in which two pulses P1. P2 is supplied to the clock input CL of the D-type flip-flop 3 and the data input, and the output Q of the D-type flip-flop 3 is latched, that is, "1" or The direction of rotation of the motor was determined by setting rOJ.

However, in such conventional devices, the D-type flip-flop 3 is generally susceptible to noise, so if noise mixes into the pulses supplied from the motor, it may malfunction (especially when the motor speed is high). There is. For this reason, conventionally, there has been a problem that the rotational direction of the motor is incorrectly determined, and depending on the configuration of the motor system, for example, the motor system may be damaged.

(Object of the Invention) The object of the present invention has been made in view of the above, and the purpose is to provide a motor with a rotational direction that is unlikely to malfunction even when noise occurs, and that can always accurately determine the rotational direction. The object of the present invention is to provide a discrimination device.

[Summary of the invention]

In order to achieve the above object, the present invention includes a rotation speed detection means for detecting the rotation speed of a motor, a pulse generation means for generating pulses having different phases generated in accordance with the rotation of the motor, and a pulse generation means for generating pulses from the pulse generation means. a rotational direction detection means for detecting the rotational direction of the motor using pulses of different phases; and a rotational direction detected by the direction detection means at or before the rotational speed of the motor reaches a predetermined rotational speed as a rotational direction discrimination signal. The gist of the present invention is to have a discrimination signal holding means for holding the discrimination signal.

[Embodiments of the invention]

Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a block diagram of a motor rotation direction determining device according to an embodiment of the present invention. In the same figure, an induction motor 1 whose rotational direction is determined is used, for example, for a vehicle, that is, for driving an electric vehicle, etc., and when it rotates in a first rotational direction, the phase changes according to this rotation. When outputting two pulses P1 and P2 with different degrees, that is, pulses Pi and P2 whose phases are different by 90 degrees as shown in Fig. 4, and rotating in a second rotation direction in the opposite direction, the phase relationship is reversed. It has a pulse generator 5.7 which outputs pulses Pi and P2 which are different by 90 degrees. Pulse P1. from the pulse generators 5, 7. P2 is supplied to the clock input CL and data input of the D-type flip-flop 3, respectively, as in FIG. 4, and is also supplied to the frequency-voltage converter, that is, the F/V converter 9. Similarly to FIG. 4, when the D-type flip-flop 3 inputs the pulses P+ and P2 to the clock input CL and data input, the output signal is latched due to the difference in phase between the two pulses due to a change in the rotational direction of the motor. It looks like this.

For example, if the motor 1 rotates in the first direction and the pulse P1 leads the pulse P2 by 90' phase as shown in FIG.
Since the low level signal of 2 is latched in the D type flip-flop 3, the D type flip flop 3 outputs a low level signal, which indicates that the motor 1 is rotating in the first direction. . Further, the motor 1 rotates in a second direction opposite to the first direction, and the pulse P1. If P2 is generated so as to proceed in the reverse direction in time in FIG. 4, and pulse P1 is delayed in phase by 90° from pulse P2,
The high-level signal of the pulse P2 at the rising edge of is latched by the D-type flip-flop 3, and the D-type flip-flop 3 outputs a high-level signal, and this high-level signal causes the motor 1 to rotate in the second direction. It is now shown that there is. However, as mentioned above, this D-type flip-flop O-tube 3 is prone to malfunction due to noise mixed into the input, especially at high rotation speeds. It is input to the data input of the knob 11, and is not affected by malfunctions as will be described later.

The F/V converter 9 inputs the pulse P1 generated from the pulse generator 5 when the motor 1 rotates, and outputs a voltage according to the frequency of the pulse P1. F/V
The output of converter 9 is connected to the inputs of two comparators 13.15. More specifically, the output of the F/V converter 9 is connected to the non-inverting input of the comparator 13 and the inverting input of the comparator 15, and the reference voltage Vr is supplied to the inverting input of the comparator 13 and the non-inverting input of the comparator 15. . This reference voltage Vr is set when the rotation speed of the motor 1 becomes greater than zero, that is, when the motor 1
The voltage is set to a value higher than the voltage from the F/V converter 9 when the F/V converter 9 starts rotating.

Therefore, when the motor 1 does not rotate and the output voltage of the F/V converter 9 is lower than the reference voltage Vr, the output of the comparator 13 becomes a low level and the output of the comparator 15 becomes a high level. Further, when the motor 1 starts rotating and the output voltage of the F/V converter 9 becomes equal to or higher than the reference voltage Vr, the output of the comparator 13 becomes a high level and the output of the comparator 15 becomes a low level.

The outputs of comparators 13 and 15 are connected to the trigger and reset inputs of the flip 70 knob 11, respectively. Therefore, the flip-flop 11 enters the reset state when a high level signal is supplied from the comparator 15 to its reset input, and if a high level signal is supplied from the comparator 13 to its reset input, the flip-flop 11 enters the reset state at the rising edge of the signal. The output level from the D-type flip-flop 3, which is supplied to the data input, is latched. That is, the flip-flop 11 is switched to the D-type flip 70 by the rising signal of the comparator 13.
A low level or high level signal indicating the rotational direction of the motor 1 supplied from the knob 3 is latched, thereby eliminating the influence of noise on the D-type flip-flop 3.

The operation of the motor rotation direction determining device configured as above will be explained.

First, when the motor 1 is not rotating, the pulse generators 5 and 7 do not output pulses Pi and P2, so the D-type flip-flop 3 does not operate, and the F/F/
The output of V converter 9 is zero, a high level signal is output from comparator 15, and the device and flip-flop 11 are in a reset state.

Next, when the motor 1 starts rotating in the first direction, pulses Pi and P2 are generated from the pulse generator 5.7. The phase relationship of the pulses when the motor 1 rotates in the first direction is such that the phase of the pulse P1 is advanced by 90' as described above. This low level output signal is applied to the data input of flip-flop 11.

On the other hand, when the motor 1 starts rotating and the pulse generator 5 outputs the pulse P1, the output pulse P1 becomes F/
It is converted to a voltage level by V converter 9 and compared with reference voltage Vr in comparator 13.15. As mentioned above, this reference voltage Vr is set approximately equal to the output voltage of the F/V converter 9 when the motor 1 starts rotating, so when the motor 1 starts rotating, the F/V
The output voltage level of converter 9 immediately becomes higher than reference voltage Vr, and at this time the output of comparator 13 changes to a high level. As a result, the rising signal of the output voltage of this comparator 13 that changes to a high level is supplied to the flip-flop 70 and the output voltage of the flip-flop 11, and at this rising point, the D-type flip-flop is supplied to the data input of the flip-flop 11. The flip-flop 11 latches the low level output signal of 3 and outputs the same low level signal from its output Q. This low level output signal indicates that the motor 1 is rotating in the first direction, as described above.

In this way, the D-type flip 7O indicates the rotation direction of the motor 1.
The output signal of the knob 3 is latched to the flip 70 knob 11 at the rising edge of the output signal of the comparator 13 at the time when the F/V converter 9 detects the start of motor rotation, and is thereafter latched and released until the motor stops rotating. Therefore, it is not affected by noise.

Furthermore, when the motor 1 starts rotating in the second direction, the pulse P1 output from the pulse generator 5.7 lags the pulse P2 by 90', contrary to the case described above.
The output of the D-type flip-flop 3 becomes high level.

For this reason, the flip-flop 11 receives a D at the rising edge of the output signal of the comparator 13 via the F/V converter 9.
A high level signal from the type flip-flop 3 is latched and output, indicating that the motor 1 is rotating in the second direction.

FIG. 2 shows another embodiment of the present invention, in which both the power and regeneration commands are switched depending on the detected motor rotation direction. In the motor rotation direction determination device J3 shown in the same figure, when the rotation speed of motor 1 is low, pulse P
There is relatively little noise mixed into I and P2, and focusing on the fact that the D-type flip-flop 3 is likely to erroneously detect the rotation direction, especially when the rotation of the motor 1 is relatively high, the rotation of the motor 1 is When the number of rotations is relatively low, that is, lower than a predetermined reference rotation speed, the rotation direction of the motor 1 is directly determined based on the output signal of the above-mentioned flip-flop 3. When the rotational speed is higher than the reference rotational speed, the rotational direction detected at a lower rotational speed is stored or held in advance, and this stored rotational direction is used.

In FIG. 2, a pulse generator 5 provided on the motor 1
．． 7 pulse P1. P2 is supplied to the D-type flip-flop 3, and pulses P1. Due to the difference in the phase of P2, motor 1
The circuit for detecting the direction of rotation is the same as the embodiment shown in FIG.

Pulse P2 from pulse generator 7 is sent to pulse counter 21
As a result, the rotation speed N of the motor 1 is output as a count value of the pulse counter 21, and is sent from the pulse counter 21 to the CPU via the input/output interface 23.
25, and is compared with a predetermined reference rotation speed NO at CPtJ25. This predetermined reference rotation speed NO is set as described above, but to explain further, even if the motor rotation direction signal Q is wrong, sudden regeneration will not occur in the motor 1. The rotational speed is set at a speed that is unlikely to occur, for example, 60 rpm or less. Further, the output signal of the D-type flip-flop 3, that is, the motor rotation direction signal Q is also supplied to the CPU 25 via the input/output interface 23. A memory 27 consisting of ROM, RAM, etc. is connected to the CPU 25, and this memory 27 stores temporary data, such as rotation direction information of the motor 1 detected at a low rotation speed, and
Programs and the like for executing the processing operations of the present motor rotation direction determining device and controlling the motor 1 are stored.

Further, a pulse width modulation, that is, a PWM oscillator 29 is connected to the input/output interface 23.
The transmitter 29 connects to the CP via the input/output interface 23.
Vector-calculated motor drive command signal V from U25
” is being supplied.

The output signal of the PWM oscillator 29 is supplied to the motor 1 via a motor driver 31 to control the motor 1.

Next, the operation of the apparatus shown in FIG. 2 will be explained with reference to the flowchart shown in FIG.

The flowchart in FIG. 3 shows the operation of the device in FIG.
In this operation, the acceleration/deceleration signal A is first read from the accelerator, and then the rotational speed N of the motor 1 is read from the pulse counter 21 ((steps 110 and 120). Rotation speed N
is compared with a predetermined reference rotation speed No. (step 130),
When the rotation speed N is lower than the reference rotation speed NO, the output signal of the D-type flip-flop 3, that is, the motor rotation direction signal Q indicating the rotation direction of the motor 1, is read through the input/output interface 23, and the read motor The rotation direction signal Q is stored in the memory 27 (step 140).
). Further, if the rotation speed N is not lower than the reference rotation speed No., that is, if the rotation speed of the motor 1 is high, the step of the process one cycle before is executed without reading and storing the motor rotation speed N in step 140. 140
The motor rotation speed N that was read and stored in the memory 27
The number of rotations N is used when the number of rotations is low.

Acceleration/deceleration signal A1 from the accelerator read as above
Based on the motor rotation speed N1 and motor rotation direction signal Q from the pulse generator 5, the rotation of the motor 1 is controlled in the following steps 150-170. That is, the motor applied voltage command signal 0 and the slip frequency command signal fs' are calculated based on the acceleration/deceleration signal A and the rotation speed N read as described above (step 150), and the motor rotation speed vector f1 is calculated from QXN. (Step 1
60). Here, the motor rotation direction signal Q is ±1. Then, a motor drive command signal (v1) is calculated based on the formula in step 170 from each signal obtained as described above, and this motor drive command signal v1 is supplied from the CPU 25 to the PWM oscillator 29 via the input/output interface 23. Then, the output signal of the PWM oscillator 29, which is generated based on this motor drive command signal 0, is sent to the motor driver 31.
The motor 1 is controlled by being supplied to the motor 1 via the motor 1 (step 170).

As seen from step 160, the motor rotation speed vector f1 is determined by the motor rotation direction signal Q, so if the motor rotation direction signal Q is an incorrect value,
For example, if the motor is an induction motor, the slip will have a significantly different value, which will seriously affect the operation of the motor. This will have a greater effect as the motor rotation speed N becomes larger, so it is important to set the reference rotation speed NO to a relatively low value.This will ensure safe motor operation. It can be done.

〔Effect of the invention〕

As explained above, according to the present invention, the rotation direction detected by the direction detecting means when the rotation speed of the motor reaches a predetermined rotation speed, for example, the rotation speed at the start of rotation, is thereafter held as a rotation direction discrimination signal. Therefore, even if noise gets mixed in after this signal is held, the rotation direction determination signal will not change due to the influence of noise, so it can always indicate the accurate rotation direction, and this device The reliability and safety of motor systems can be improved.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a motor rotation direction determining device according to one embodiment of the present invention, FIG. 2 is a block diagram of a motor rotation direction determining device according to another embodiment of the present invention, and FIG. 3 is a block diagram of a motor rotation direction determining device according to another embodiment of the present invention. FIG. 4 is a flowchart showing the operation of the device, and FIG. 4 is a diagram showing the main part of a conventional motor rotation direction determining device. 1...Motor 3...D-type flip-flop 9...F/V converter 11...Flip-flop 13.15...Comparator Fig. 1

Claims (2)

[Claims] (1) A rotation speed detection means for detecting the rotation speed of the motor, a pulse generation means for generating pulses with different phases generated according to the rotation of the motor, and a rotation of the motor by the pulses with different phases from the pulse generation means. a rotational direction detection means for detecting a direction; and a discrimination signal holding means for holding the rotational direction detected by the direction detection means at or before the rotational speed of the motor reaches a predetermined rotational speed as a rotational direction discrimination signal. A motor rotation direction determining device comprising: (2) The motor rotation direction determining device according to claim 1, wherein the predetermined rotation speed is the rotation speed at the time when the motor starts rotating from a stopped state.