JPS63121490A - Controller for brushless motor - Google Patents

Abstract

PURPOSE:To start a rotor surely, by setting an exciting phase pattern based on a phase signal and a speed pulse signal. CONSTITUTION:Three sets of phase signals, having the pulse width of 60 deg. or 120 deg., are produced with the phase difference of 60 deg. by a phase signal generating means in accordance with the rotation of a rotor while a speed pulse signal, having a frequency proportional to a rotating speed, is produced by a speed detecting means. Upon starting, an exciting phase pattern in 30 deg. of the first half of the rotor rotating range of 60 deg., which is commanded based on the condition of a phase signal, is set by an initial setting means as an initial exciting phase pattern. When an excitation is started, the speed pulse signal is counted by a counting means. When the contents of counting effected by the counting means is decided by a deciding means that it has not arrived at a predetermined number yet, a next exciting phase pattern is set by a setting control means. On the other hand, when the content of the counting has arrived at the predetermined number, an exciting phase pattern, next to a next initial exciting phase pattern, is set.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a control device for a brushless motor, and particularly to a control device for starting and controlling a three-phase brushless smoke driven by two-phase excitation. This relates to the III device.

(Prior Art) In a control device for a three-phase brushless motor, for example, a commonly known brushless motor equipped with a three-phase stake and a four-pole permanent magnet rotor, there is a method for detecting the rotational position of the rotor. The Hall elements are arranged so that they generate a phase symbol with a pulse width of 90 degrees with a phase difference of 60 degrees, and for every 30 degrees of rotation of the rotor. A signal for switching the excitation phases of the two stators was generated by logically processing three phase signals from the Hall elements. However, in the brushless motor control device using the Hall element described above, it is necessary to perform logic processing many times in order to generate the excitation phase switching signal, and the circuit configuration or processing program to execute this is complicated. Ta.

Therefore, instead of the Hall element, we used an optical sensor that detects the slot of the rotating plate attached to the output shaft of the motor, and uses a 60-degree phase difference to detect three phases with a pulse width of 60 degrees or 120 degrees. The three phase signals are used directly as signals to switch the excitation of one stator of the two stators to be alternately excited every 30 degrees of the rotor, and the signal to switch the excitation of the other stator is applied to the motor. In order to detect the rotational speed of the rotor, a method can be considered in which the number of slits formed in the rotating plate is counted according to the rotation of the rotor. With this method, the load of arithmetic processing for generating excitation switching signals in the motor control device is reduced, and signal processing can be performed accurately even when the motor is running at high speed.

(Problem to be Solved by the Invention) However, in the brushless motor control device using the optical sensor described above, when starting the motor, one stator is excited by three phase signals from the optical sensor. Although the stator to be excited can be identified, the motor of the other stator is not rotating and passing through the aforementioned large number of slits cannot be detected, so the stator to be excited cannot be identified. For this reason, if the other stator is erroneously excited, the motor cannot be started, and there is a problem that starting the motor becomes uncertain.

(Objective of the Invention) The object of the present invention is to change the excitation state of the excitation pole every 30 degrees by using three sets of phase signals with a 60 degree phase difference and a pulse width of 60 degrees or 120 degrees and a speed pulse signal. To provide a control device for a brushless motor that can reliably start a three-phase brushless smoke driven by two-phase excitation due to switching.

(Means for Solving the Problems) As shown in the functional block diagram of FIG. 1, the brushless motor control device according to the present invention has a phase difference of 60 degrees depending on the rotation of the rotor of a three-phase brushless motor. and a speed detection means for generating a speed pulse signal having a frequency proportional to the rotational speed of the brushless motor. An excitation phase pattern for exciting two-phase stators among the three-phase stators of the motor is switched in a predetermined order every 30 degrees of rotation of the rotor, and the rotational speed of the brushless motor is set to a desired speed according to the speed pulse signal. A control device for a brushless motor to control, wherein the speed detection means is configured so that a predetermined number of the speed pulse signals are generated during 30 degrees of rotation of the rotor of the brushless motor, and the speed detection means is configured to generate a start command for the brushless motor. an initial setting means for setting, as an initial excitation phase pattern, an excitation phase pattern in the first half of the 60 degree rotor rotation range indicated by the signal state of the phase signal, and excitation according to the initial excitation phase pattern. comprising a counting means for counting the speed pulse signal for a predetermined time from the start, and a determining means for determining whether the count content of the counting means has reached the predetermined number after the elapse of the predetermined time; When it is determined that the count content of the counting means does not reach the predetermined number, an excitation phase pattern next to the initial excitation phase pattern is set, and when it is determined that the count content has reached the predetermined number, the excitation phase pattern is set. The apparatus includes a setting control means for setting an excitation phase pattern two after the initial excitation phase pattern.

(Function) In the brushless motor control device according to the present invention,
The phase signal generating means generates 60 degrees or 12 degrees with a phase difference of 60 degrees depending on the rotation of the rotor of a three-phase brushless motor.
Three phase signals with a pulse width of 0 degrees are generated, a speed pulse signal with a frequency proportional to the rotational speed of the brushless motor is generated by the speed detection means, and the three phase signals of the brushless motor are detected based on these three sets of phase signals. The excitation phase pattern for exciting the 02-phase stator in the stator is controlled to be switched in a predetermined order every 30 degree rotation of the rotor, and the rotational speed of the brushless motor is controlled to a desired speed in accordance with the speed pulse signal.

When starting the brushless motor, the initial setting means
The excitation phase pattern in the first half of 30 degrees of the 60 degree rotor rotation range designated based on the signal state of the phase signal is set as the initial excitation phase pattern.

When this initial excitation phase pattern is set and excitation is started, the counting means counts speed pulse signals for a predetermined period of time.

When a predetermined time has elapsed, the determining means determines whether the count counted by the counting means has reached a predetermined number.

Also, the count content of the speed pulse signal counted by the counting means has not reached the predetermined number (the rotor has not started)
When it is determined that this is the case, the setting control means sets the next excitation phase pattern after the initial excitation phase pattern, so that the rotor is reliably started.

Further, when it is determined that the count content has reached a predetermined number (the rotor has started rotating), the setting control means sets the excitation phase pattern two after the initial excitation phase pattern. The rotational speed of will rise to 2.

(Effects of the Invention) According to the control device for a brushless motor according to the present invention, as explained above, when starting the brushless motor, first, as an initial excitation phase pattern, the rotor rotation range of 60 degrees determined by the signal state of the phase signal is set. The first half of the excitation phase pattern of 30 degrees is set, and when the rotor does not start, the second half of the excitation phase pattern of 30 degrees is set, so that the rotor is reliably started.

In this case, even if the rotational position of the rotor is at the final stage of 30 degrees in the first half and the rotor does not start due to insufficient torque, the strong torque generated by the excitation phase pattern of 30 degrees in the second half will ensure startup.

Further, when the rotor is started according to the initial excitation phase pattern, the excitation phase pattern two after the initial excitation phase pattern is set, so the rotation of the rotor is accelerated and the time required for the rotational speed to rise is shortened.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 2, this embodiment includes a four-pole permanent magnet rotor 1 in which S poles and N poles are alternately arranged, and three excitation poles U and
This is a control device for controlling a three-phase, four-pole brushless motor M consisting of a three-phase stator 2 and a three-phase stator 2 with two-phase excitation, and is particularly characterized in starting control of the motor M. A U corresponding to the U-phase excitation coil 4U of the three phases is
A phase sensor 5U, a phase sensor 5 corresponding to the V-phase excitation coil 4V, and a rotation pulse sensor 6 for optically detecting the rotation speed and rotation angle of the brushless motor M are provided. U phase sensor 5U at
The W-phase signal S8 is synthesized from the U-phase sensor signal Su output from the V-phase sensor 5 and the ■-phase sensor signal Sv output from the V-phase sensor 5■, and these signals Su' Sv '' St=
The control is performed based on the rotation pulse signal S and the rotation pulse signal S.

When starting the motor M, a U-phase sensor signal So and a ■-phase sensor signal Sv are used to ensure that the motor M is started.
The excitation phase pattern of 30 degrees in the first half of the rotation range of the rotor 1 of 60 degrees indicated by the signal state is set as the initial excitation phase pattern, and when the rotor 1 does not start, that is, it rotates more than the set number of times in a predetermined time. When the pulse signals S and l are not input, the next excitation phase pattern is set, and when the rotor 1 starts, that is, when more than the set number of rotation pulse signals SR are input in a predetermined time, two from the initial excitation phase pattern are set. This is to set the later excitation phase pattern.

As shown in Fig. 2, the brushless motor M has an S pole and an N pole.
A four-pole rotor 1 with alternating poles, U phase, ■ phase,
It is composed of a three-phase stator 2 of W phase, U phase, V phase, W phase.
Excitation coils (hereinafter referred to as U-phase coil 4Fv-phase coil 4V and W-phase coil 4W) are wound around each phase in the same way as in the existing brushless motor M.

The excitation angle for exciting each phase coil of the U-phase coil 4U-V-phase coil 4■ and W-phase coil 4W of the brushless motor M is as shown in FIG. From 120°, which is the angle, to 9, which is the opening angle of each magnetic pole of rotor 1.
If 30°, which is obtained by subtracting 0°, is a unit angle, in the case of one-phase excitation, the unit angle is 30°, and in the case of two-phase excitation, it is 60', which is twice the unit angle.

In addition, when the three-phase stake 2 is controlled by two-phase excitation, as shown in FIG.
・The W side must have different polarity combinations of N and S poles, such as U phase N pole - ■ phase S pole, U phase N pole - W phase S pole, ■ phase N pole - W phase S pole , V phase N pole - U phase S pole, W phase N pole - U phase S pole, and W phase N pole - ■ phase S pole.

Therefore, the direction of current corresponding to the six combinations is U
Phase → ■ phase, U phase → W phase, ■ phase → W phase, ■ phase → U phase, W phase → U phase, W phase → ■ phase, U phase coil 4U, ■ phase coil 4V, W phase coil 4W. It is necessary to selectively switch the direction of the current as appropriate, and the direction of the current can be switched using two types of transistors UA - of the driver shown in Fig. 4.
It is controlled by switching VA', WA, Um'Vm, and Wl, respectively.

The rotating slit plate 3 is a circular metal plate fixed to the motor shaft 1a, as shown in FIG.
A number of approximately square slits 7 for speed and rotation angle detection are formed at equal intervals, and on the inner circumferential side of the slits 7, a pair of U finger sensors 5U extending over an angle of 60'' are curved. A shaped slit 8U is formed symmetrically with respect to the axis of the motor shaft 1a, and on the inner circumferential side of this slit 8U, a pair of curved slits 8 for the finger sensor 5V are formed over an angle of 60°.
V is formed symmetrically with respect to the axis of the motor shaft 1a, and this pair of slits 8■ is provided at a position with a phase delay of 60'' with respect to the pair of slits 8U. 9 indicates the forward rotation direction of the brushless motor M.

At one location in the circumferential direction of the rotating slit plate 3, a sensor mounting block 10 having a U-shape in plan view is provided to sandwich the rotating slit plate 3 in a non-contact manner, and this sensor mounting block 10 emits light. Three sets of photosensors consisting of an element (such as a photodiode) and a light receiving element (such as a phototransistor) are connected to each of the slits 7, 8U, and 8V.
They are installed in such a way that they correspond to each other.

As shown in FIG. 5, a rotation pulse signal S8 in the form of a rectangular pulse is output from the rotation pulse sensor 6 corresponding to the slit 7.
is output, and inverters 15 and 16 are interposed in the output lines of the U finger sensor 5U corresponding to the slit 8U and the V finger sensor 5v corresponding to the slit 8■, respectively. The U-phase sensor signal Su that becomes "L" level when approaching slit 8U is output, and the V-phase sensor signal Sv that becomes "L" level when reaching slit 8V is output from V finger sensor 5■. be done.

Next, a control device for controlling the brushless motor M will be explained based on the block diagram of FIG. 4.

This control device includes a start/stop switch (STPSW) 26 for starting and stopping the motor M, a rotary slit plate 3, the sensors 5U, 5, 6, inverters 15, 16, a NAND game) 17, a speed command section B, and a control section. It consists of C and a driver section.

The start/stop switch 26 is activated only when it is operated.
Return type 0N10F that outputs l and J level signals ST
This signal ST is output to the phase switching circuit 27.

In the phase switching circuit 27, this signal ST is input to the terminal CK of the JK flip-flop (not shown), and the start/stop control signal 5TPC from the output terminal Q is input.
is output to the register 30.

The register 30 holds this start/stop control signal 5TPC while outputting a gate signal GS substantially the same as this signal to the AND gate 22.

That is, each time the start/stop switch 26 is operated, the signal ST'PC and the gate signal GS are alternately inverted to "H" level and "L" level signals, and when the signal is at the "H" level, the brushless signal is activated. Morph M is rotationally driven.

The rotation pulse signal SII from the rotation pulse sensor 6 is sent to the clock terminal CK of the quinary counter 21 and the phase switching circuit 2.
7, enable terminal EN of the pulse width calculator 32, and A
A clock signal qct of 500 KHz is output to the input terminal of the ND gate 22 and the inverter 24, and the input terminal of the AND gate 22 receives the clock signal qct.

is input, and the output line of the AND gate 22 is connected to the clock terminal CK of the speed detection counter 23.

In addition, an inverter 24 is connected to the input terminal of the AND gate 25.
The output of AN and the clock signal of 2KH2 are input, and the AN
An output line of the D gate 25 is connected to a reset terminal RT of the speed detection counter 23.

The speed detection counter 23 counts the clock signal CL when both the rotation pulse signal SR and the gate signal GS input to the AND gate 22 are at "H" level, and the speed detection counter 23 counts the counted value, that is, the speed detection. The signal N is output to the pulse width calculator 32.

When the rotation pulse signal SR is at the "H" level, the speed detection counter 23 counts the clock signal CL and outputs the speed signal N. When the rotation pulse signals S and I are at the "L" level, the AND gate 25 receives the 2KH2 clock signal and outputs a reset signal R every 2KHz to the terminal RT of the speed detection counter 23, and uses this reset signal R to reset the speed detection counter 23.

Speed command section B consisting of potentiometer 14 etc.
The selected signal is converted into a speed command signal No. by the A/D converter 33 and then output to the pulse width calculator 32.

In the pulse width calculator 32, the speed of the brushless morph M is controlled by pulse width modulation based on the speed signal N input from the speed detection counter 23 and the speed command signal No input from the A/D converter 33. Pulse width for (
PNP (driver part) transistor U, ・■1 ・W
The pulse width of the positive excitation control pulse applied to A is calculated at the timing of the fall of the rotation pulse signal S11, and the pulse width signal PWS is temporarily stored in the register 31 and is also applied to each of the gate circuits 34U, 34V, and 34W. is output to.

The U-phase sensor signal Su from the U-phase sensor 5U is output to the one-shot multipipe lake 18, one input terminal of the NAND gate 17, and the phase switching circuit 27, and the
The V-phase sensor signal Sv from the phase sensor 5v is output to the one-shot multi-by-break 18, the other input terminal of the NAND gate 17, and the phase switching circuit 27, and this NAND
The gate 17 receives the U-phase sensor signal SU and the ■-phase sensor signal Sv.
It outputs a W-phase signal Sw (see Figure 5) from
The W-phase signal Sw is output from the NAND gate 17 to the one-shot multipipe lake 18 and the phase switching circuit 27.

The one-shot multi-by-break 18 outputs a trigger signal at the falling edge of each of the U-phase sensor signal Su, the V-phase sensor signal Sv, and the W-phase signal Sw.
Three output lines corresponding to the three signals are connected to the input terminals of the OR gate 19, respectively, and the output lines from the OR gate 19 have a phase angle of 60
The trigger signal for each degree (see FIG. 5) is sent to the phase switching circuit 27 as a signal T. It is also output to the reset terminal RT of the quinary counter 21 via the OR gate 20.

Further, when the start/stop switch 26 is operated and the start/stop signal 5TPC rises to the "H" level, the counter reset signal CRT is sent from the phase switching circuit 27.
(trigger signal) is output to the OR gate 20, and the quinary counter 21 is reset every time it receives the trigger signal from the OR gate 20.

The quinary counter 21 counts five rotation pulse signals SII upon receiving the trigger signal from the OR gate 20,
When the count of 5 pieces (i.e., the slits 7 are provided at intervals of 6 degrees, so 6 degrees x 5 = 30 degrees) is completed, a carry signal T, (see FIG. 5) is sent to the phase switching circuit 27. Output.

The phase switching circuit 27 receives the signal T from the OR gate 19,
. Based on the carry signal T s i from the quinary counter 21, the excitation of the U-phase coil 4U, the ■phase coil 4■, and the W-phase coil 4W is switched and controlled.

The phase switching circuit 27 is connected to the CPU (central processing unit) and the RO.
M (read-only memory) and RAM (random
As shown in FIG. 6, this ROM includes a pressure phase pattern Pal, Pl, Pi3 that positively excites any of the phase coils 4U, 4, and 4W.
3 types of positive excitation data Da and each phase coil 4U/4V
- Reverse excitation phase pattern Pbl that reverse excite any of the 4W
' Three types of reverse excitation data Db, Pb2 and Pl, are stored.

3 types of forward excitation data D1 and 3 types of reverse excitation data D
, "1" indicates the excited phase and "0" indicates the non-excited phase, and the positive excitation data D of the patterns P□ and Pat' P m3 are U phase coil 4U-V phase coil 4V-W phase coil 4W, respectively. Specify the excitation of the pattern Pl+I' pb
Reverse excitation data D of z and Pb3 are respectively ■phase coil 4V-
This specifies the excitation of the W-phase coil 4W-U11 coil 4U.

The excitation phase pattern of the motor is determined by the combination of the forward excitation phase pattern Pa+'Pat'Pus and the reverse excitation phase pattern Pbl'Pbt/Pb3.For the forward excitation data D, the signal T. It is switched in the order of P□→P, →Pa3→P0 for each input, and
The reverse excitation data D1 is switched in the order of Pbl→P and →Pb3→P each time the carry signal TIM is input.

The switching control of the patterns during starting and driving of the motor M will be described later based on the flowchart of FIG. 7, and a control program for this switching control is stored in the ROM.

The phase switching circuit 27 outputs forward excitation data D to the register 28 and reverse excitation data D to the register 29.

Then, in the register 28, the positive excitation data D,
At the same time, when the positive excitation data D1 is pattern P1, the U-phase pressure magnetic dynamic signal Gu is output to the U sum gate circuit 34U, and when the pattern P, z, the phase pressure magnetic dynamic signal Gv is output to the ■ sum gate. Output to circuit 34V, pattern P
. When , the W-phase piezomagnetic signal Gw is sent to the W-sum gate circuit 34.
Output to W.

On the other hand, the register 29 temporarily stores the reverse excitation data D, and also stores the reverse excitation data D.

However, in the case of pattern Pb3, the U-phase reverse excitation signal CCU is output to the base of the U-phase transistor U, and pattern P
, the V-phase reverse excitation signal CCv is output to the base of the V-phase transistor vl, and when the pattern is pbt, the V-phase reverse excitation signal CCv is output to the base of the V-phase transistor vl.
The mutual excitation signal CCw is output to the base of the W-phase transistor W8.

When the U-sum gate circuit 34U receives the U-phase piezomagnetic signal Gu, the gate opens and the pulse width signal PWS is sent to the U-phase counter 35.
It is output to the preset terminal PR3 of U.

This means that the V sum gate circuit 34V and the W sum gate circuit 3
The same goes for 4W, and when the V sum gate circuit receives the V phase piezomagnetic signal Gv, the pulse width signal PWS changes to the V phase counter 3.
5V is output to terminal PR3, and the W sum gate circuit also outputs W
Upon receiving the phase pressure magnetic dynamic signal G8, a pulse width signal PWS is outputted to the terminal PR3 of the W-phase counter 35W.

Next, the U-phase counter 35U is a subtraction counter, and receives a pulse width signal PWS from the U sum gate circuit 34U, a clock signal CL of 500KH at its terminal CK, and a clock signal of 2KH at its load terminal LD. In the U-phase counter 35U, the pulse width is set every time a load signal of 2KH is received, and the clock signal C
By counting L, the U-phase piezomagnetic count signal Ku from which the pulse width commanded by the pulse width signal PWS is being subtracted continues to be output to the U-phase discrimination circuit 36U.

This means that the ■ phase counter 35V and the W phase counter 35V
The same goes for W, the V-phase pressure-magnetic count signal Kv is output from the ■phase counter 35■ to the V-phase discrimination circuit 36V, and the W-phase counter 35W outputs the V-phase pressure-magnetic count signal Kv to the W-phase discrimination circuit 36W.
A W-phase pressure-magnetic dynamic count signal Kw is output to the output terminal.

The U-phase discrimination circuit 36U is composed of an OR gate, a one-shot multi-by-break, and an RS flip-flop, and discriminates O of the U-phase piezomagnetic count signal Ku from the U-phase counter 35U (by deactivating the U-phase coil 4U). U-phase pressure dynamic count signal K for positive excitation due to utility cycle
This is a circuit for U (stops excitation of the U-phase coil 4U by Do), the positive excitation count signal Ku from the U-phase counter 35U is input to the OR gate, and the output signal of the OR gate is passed through the one-shot multi-by-break. A clock signal of 2KH is input to the terminal R of the RS flip-flop, and the U-phase positive excitation control pulse Pu from the output terminal Q is input to the terminal S of the RS flip-flop.
It is output to the base of the phase transistor UA.

That is, the U-phase positive excitation control pulse Pu of rl, J level, which falls every time a clock signal of 2KH is input, and rises when the U-phase piezomagnetic count signal Ku becomes O, is applied to the U-phase transistor U.
Output to the base of A.

This means that ■phase discrimination circuit 36V and W phase discrimination circuit 36W
The same goes for ``L'' level, which falls every clock signal.
The phase pressure dynamic magnetic control pulse Pv is output to the base of the V-phase transistor vA, and the W-phase pressure dynamic magnetic control pulse at the "L" level rises when the W-phase pressure dynamic magnetic count signal Kw falls every clock signal and becomes O. Control pulse Pw is output to the base of W-phase transistor WA.

The above U-phase coil 4U, ■phase coil 4■, and W-phase coil 4W
The driver section for the above PNP) transistor UA
'VA 'WA and NPN) transistor U,・■8
・W3 and high frequency diode D+u'D+v' Dew・Dzu-Dzv as flywheel diode
-Dz, consists of 4.

Regarding the U-phase, the emitter of the transistor U^ is connected to a DC power supply, the collector of the transistor Ua and the collector of the transistor U are connected, one end of the U-phase coil 4U is connected to the connection point, and the collector of the transistor Ua is connected to the collector of the transistor U. A diode Dlu is connected between the emitter and the emitter as shown.
is connected, a diode DZL+ is connected as shown between the emitter and collector of transistor UII, and the emitter of transistor U is grounded.

This is the same as above for the ■ phase and the W phase, and the V phase coil 4 is connected to the connection point between the V phase transistors ■ and V.
One end of ■ is connected, and the W-phase transistor WA and W
One end of the W-phase coil 4W is connected to the connection point of ,
The U-phase coil 4U, the ■phase coil 4■, and the W-phase coil 4W are star-connected.

For example, as in the case of a phase angle of 15° in FIG.
A U-phase pressure-magnetodynamic control pulse PLl is applied to the base of the U-phase transistor UA, and a pulse PLl is applied to the base of the V-phase transistor V.
When the mutual excitation control signal CCv is applied, the transistor UA repeats ON and OFF so that the duty ratio corresponds to the pulse width signal PWS, and the current from the DC power supply flows through the transistor UA-+U-phase coil. The flow is 4U→■phase coil 4V→transistor Vm→ground, and the U-phase coil 4U is positively excited and the ■phase coil 4■ is reversely excited.

Then, as the duty ratio increases (pulse width increases), the conduction time of the transistors UA'VA and WA of each phase becomes longer, and the pulse width modulation causes each phase coil 4U and 4
(2) The current flowing through 4W increases, and the rotation speed of the brushless morph M increases.

At this time, each time the transistor Ua chops from ON to OFF, a current flows in the same direction as before through the U-phase coil 4U and the ■phase coil 4 due to self-induction, and this induced current flows into the U-phase coil 4U. →■Phase coil 4■→Transistor ■8→Diode I)zu→U phase coil 4U
Flows along the circuit of U phase coil 4U and ■ phase coil 4V
Current will flow continuously.

In other words, the flywheel diode Dzu・I)zv・
D2- is provided for pulse width modulation.

Furthermore, when the ■phase transistor V is switched from ON to OFF, the self-induced current flows from U-phase coil 4U to ■phase coil 4.
■→Diode DIv-+U phase transistor UA-+U
Since the self-induced current flows along the circuit of the phase coil 4U, the self-induced current is effectively utilized.

Next, switching control of the excitation phase pattern at the time of starting and driving the brushless morph M will be explained with reference to the flowchart of FIG. 7, but first a brief overview thereof will be given.

As can be seen from FIG. 5, the combinations of the U-phase sensor signal Su and the ■-phase sensor signal Sv and the positive excitation phase patterns corresponding to each combination are as shown in the following table.

When the morph M starts up, the positive excitation phase pattern Pal, Pm2, P is generated depending on the combination (signal state) of the signal Su and the signal Sv.
Although m3 is determined, two reverse excitation phase patterns Pbl, pbz, and Pb3 are possible for each signal state. For example, in the case of a phase angle of 0° to 60°, in the first half of 30°, ■
Pattern Pb+ (Db
: 010), and in the latter half of 30°, the W-phase coil 4W
This is a pattern Pw (Db: 001) for reverse excitation.

Therefore, as the initial excitation phase pattern at startup, the signal Su
The brushless morph is controlled to have an excitation phase pattern of 30° in the first half of the phase angle of 60° determined by the signal state of the signal Sv and the signal Sv, and the brushless morph is activated if the rotation pulse signal S exceeding the set value is not input within a predetermined time. If it is determined that the
Is it controlled so that it becomes the next excitation phase pattern, the second half of the excitation phase pattern of 30°? 11, and if the activation is controlled by the initial excitation phase pattern and it is determined that the rotation pulse signals S and I exceeding the set value are input within a predetermined time and activated, the excitation phase two after the initial excitation phase pattern is activated. It is controlled so that it follows a pattern.

Next, the steps of the start-up control performed by the phase switching circuit 27 will be explained with reference to the flowchart of FIG.

When the power is turned on to this control device, this control is started, and in step Sl (hereinafter simply referred to as Sl, and other steps are handled in the same way), initial settings are performed and S2
Move to.

In S2, it is determined whether the start/stop switch 26 has been operated, and if it has not been operated, the process moves to S3, where the start/stop control signal 5TPC is set to O, which is written to the register 30, and the process proceeds from S3 to S2.
Steps S2 and 83 are repeated at minute intervals, and when the start/stop switch 5TPSW 26 is operated, the step moves to 34.

At S4, the counter reset signal CRT and the start/stop control (No. 8 5TPC) are set to "1", the counter reset signal CRT is output from the phase switching circuit 27, and the start/stop control signal 5TPC is output from the register. 30 and held.

In the next step 35, the counter reset signal CRT outputted in S4 is stopped, and the quinary counter 21 is reset by this counter reset signal CRT.

In the next step 36, it is determined whether the U-phase sensor signal Su is "1" or not, and when it is "1", the process moves to S8 and the signal is "1" again.
If not, the process moves to S7.

In S7, it is determined whether the ■phase sensor signal Sv is "1" or not. When it is "1", the process moves to S9, and when it is not "1", the process moves to SIO.

Further, in S8, it is determined whether the V-phase sensor signal Sv is "1" or not, and when it is "1", the process moves to S11 and "
If the value is not 1, the process moves to SIO.

S9 is, for example, when the phase angle in FIG. The pattern Pbl is set to excite the coil 4■.

310 is, for example, when the phase angle in FIG.
is set to a pattern Pb□ that excites the W-phase coil 4w.

Sll is, for example, when the phase angle is 12o° to 180° in FIG.
is set to pattern Pb3 that excites the U-phase coil 4U.

In the next step 312, the forward excitation data D and the reverse excitation data D, which are the initial excitation phase patterns set in S9, sio, and Sll, are output, and the U-phase coil 4U, V-phase coil 4V, and W-phase coil 4W is normally excited or reversely excited in accordance with the forward excitation data D and reverse excitation data D.

In the next step 313, the soft counter I provided in the control device is reset.

In the next step 314, a timer provided in the CPU starts counting time.

In the next step 315, it is determined whether or not the rotation pulse signal S8 is input. If the rotation pulse signal SR is not input, the process moves to 317. If the rotation pulse signals S and I are input, the process moves to 316 and the software is 1 is added to the counter ■ and the process moves to 317.

In 317, it is determined whether a predetermined time, for example, several hundred m5, has elapsed since the time measurement was started in 314. If the predetermined time has not elapsed, steps 315 to 317 are repeated, and when the predetermined time has elapsed, the process moves to 318. .

At 318, the counter value ri of the soft counter ■
It is determined whether J is equal to or greater than the set value "n" (the set value for the timing at which the reverse excitation phase should be switched), and when it is equal to or greater than the set value, the forward excitation data D and reverse excitation for starting the brushless motor M are When the pattern of the data Db is correct, the process moves to 325, and when it is smaller than the set value, that is, when the pattern of the reverse excitation data D is incorrect, the process moves to S19.

In S25, the rotor 1 of the brushless motor M has started to rotate, so each of the forward excitation data D1 and reverse excitation data D in S9.5IO1S11 has a pattern shifted by one (that is, P1→Pi□→P m3") ”
” In the order of P ml, also Pbl → PbZ → Pb1-P
(patterns shifted in the order of bl).

The next steps S19 to S21 are the same as S6 to S8 above, and are steps for again classifying the U-phase sensor signal Su and the V-phase sensor signal Sv according to their signal states, and in 319, the U-phase sensor signal Su is 1” is determined, and “1” is determined.
'', the process moves to S21, and when it is not ``1'', the process moves to S20.

At step 320, it is determined whether the ■ phase sensor signal Sv is "1" or not.
If not, the process moves to S23.

Further, in 321, it is determined whether the ■ phase sensor signal Sv is "1" or not. When it is "1", the process moves to S24, and when it is not "1", the process moves to S23.

At 322, the forward excitation data D is set to a pattern P M+ that excites the U-phase coil 4U without changing, while the transmission excitation data D is set to a pattern pbz that excites the W-phase coil 4W.

In S23, the forward excitation data D is set unchanged to the pattern P1□ that excites the V-phase coil 4v, while the sending excitation data Db is set to the pattern p that excites the U-phase coil 4U.
set to bi.

At 324, the forward excitation data D1 is set to a pattern Pa3 that excites the W-phase coil 4W without changing, while the sending excitation data D is set to a pattern P1++ that excites the phase coil 4W.

In the next step 326, the forward excitation data D1 and reverse excitation data Db set in steps 322 to 325 are output, and the U-phase coil 4U, ■phase coil 4■, and W-phase coil 4W are outputted with the forward excitation data D1 and reverse excitation data Corresponding to Db, the rotor 1 is forwardly excited or reversely excited, and thereby the rotor 1 starts to start.

The next 327 to 32B are positive excitation data D, pattern P0
・This is a step to sequentially shift P1□・Pa3 (
(See FIG. 5), it is determined in S27 whether the output signal T8° of the OR gate 19 is "1", and when it is "1", the process moves to 828, and when it is not "1", the process moves to S29.

At 328, the forward excitation data D of the pattern shifted by one is output to the register 28, and the reverse excitation data D is output to the register 29.

The next S29-S30 is a pattern Pb of reverse excitation data D.
This is a step of sequentially shifting l'Pbt' pb:t (see FIG. 5), and in S29 it is determined whether the output signal Tit of the quinary counter 21 is "1" or not.
When it is "1", the process moves to S30, and when it is not "1", the process moves to S31.

In S30, the reverse excitation data D of the pattern shifted by one is output to the register 29, and the forward excitation data D is output to the register 28.

In the next step 331, it is determined whether or not the start/stop switch 26 has been operated (or not to stop the rotation of the rotor 1), and if it has not been operated, the process moves to 327, and 52
By repeating steps 7 to 331, the rotor 1 is continuously driven to rotate, and when the rotor 1 is operated, the process moves to S32.

In S32, the start/stop control signal 5TPC is set to "0" and written to the register 30, and thereby the gate signal GS becomes "L" level, the operation of the speed detection counter 23 is stopped, and the rotor 1
Prepare to stop rotating.

In the next step 333, forward excitation data and reverse excitation data Db that do not excite any phase coil are set.

In the next step 334, the forward excitation data D1 set in 333 is stored in the register 28, and the reverse excitation data D is stored in the register 29.
The rotation of the rotor 1 is stopped, and the process moves from S34 to S32.

As explained above, in the control device for the brushless motor M of this embodiment, the W-phase signal Sw is synthesized with the U-phase sensor signal Su and the ■-phase sensor signal Sv, thereby omitting the W-phase sensor and Depending on the signal states of the phase sensor signal Su and the ■phase sensor signal Sv, the rotor 1 is started according to the initial excitation phase pattern for starting the rotor 1, and when the rotor does not start according to the initial excitation phase pattern, the next excitation phase pattern is activated. This allows the rotor 1 to be reliably started.

Note that this example merely shows one example of the present invention.
Those skilled in the art can make various modifications without departing from the spirit of the invention.

Note that the control section C may be configured with a microcomputer or the like.

Note that control for reversing the brushless motor M can be achieved by sequentially shifting the excitation phase patterns of the forward excitation data D1 and the reverse excitation data D in a direction opposite to the forward rotation.

Note that the advantage of controlling the rotational speed of the brushless motor M by pulse width modulation is the same as that of existing DC motors.

[Brief explanation of the drawing]

Fig. 1 is a functional block diagram of a control device for a brushless motor according to the present invention, Figs. 2 to 7 show embodiments of the control device for a brushless motor, and Fig. 2 is a vertical cross-section of essential parts of the brushless motor. Figure 3 is a front view of the rotating slit plate and three sets of sensors, Figure 4 is a configuration diagram of the brushless motor control device, and Figure 5 is the sensor signal of each phase and the excitation and reverse excitation of each phase coil, etc. FIG. 6 is an explanatory diagram explaining the forward excitation and reverse excitation patterns of each phase coil when starting the brushless motor, and FIG. 7 is a flowchart of the brushless motor startup control routine performed by the control device. be. M...Brushless morph, 1...Rotor, 1a...
Motor shaft, 2... Stator, U, ■, W... each U
Phase/V phase/W summation magnetic pole, 3...Rotating slit plate, 4
U, 4v, 4W... U phase coil, V phase coil, W phase coil respectively, 5U, 5V... U phase sensor, V phase sensor respectively, 6... Rotation pulse sensor, 7... Slit, 8U, 8V...・Each curved slit, 17・
・NAND gate, 21...quintal counter, 2
3. Speed detection counter, 26. Start/stop switch, 27. Phase switching circuit, 28. Register, 29.
・Register, 32...Pulse width calculator, 33...A/
D converter, 35U/35V/35W... each phase counter, B... speed command section, C... control section, D...
Driver section, UA, ■1, WA...PN of each phase
P transistor, U, ・V, ・Wm ・NPN) transistor for each phase, D, U-D, v-D, ・・
Diode, D2LI' D! V “Ihti”
Diode, D, -・Forward excitation data, Db...
Reverse excitation data. Figure 1

Claims (1)

[Claims] (1) Phase signal generating means for generating three phase signals having a pulse width of 60 degrees or 120 degrees with a phase difference of 60 degrees according to the rotation of the rotor of a three-phase brushless motor, and the rotational speed of the brushless motor. and speed detection means for generating a speed pulse signal with a frequency proportional to the frequency, the excitation phase pattern for exciting two of the three-phase stators of the brushless motor is set in a predetermined order every 30 degrees of rotation of the rotor. A brushless motor control device that controls the rotational speed of the brushless motor to a desired speed according to the speed pulse signal, wherein the speed pulse signal is switched at a predetermined speed during 30 degrees of rotation of the rotor of the brushless motor. the speed detecting means is configured to generate an excitation phase pattern in the first half of a 30-degree rotor rotation range of 60 degrees indicated by the signal state of the phase signal when a start command for the brushless motor is generated; initial setting means for setting as an initial excitation phase pattern; counting means for counting the speed pulse signal for a predetermined time from the start of excitation according to the initial excitation phase pattern; and counting contents of the counting means after the elapse of the predetermined time. determining means for determining whether or not the predetermined number has been reached; and setting an excitation phase pattern next to the initial excitation phase pattern when it is determined that the count content of the counting means does not reach the predetermined number; A control device for a brushless motor, comprising a setting control means for setting an excitation phase pattern two after the initial excitation phase pattern when it is determined that the count reaches the predetermined number.