JP2006325346A - Method and apparatus for controlling brushless motor and brushless motor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device for brushless motors wherein malfunction due to noise can be prevented. <P>SOLUTION: A microcomputer 30 performs such operations that: it carries out interrupt handling each time a phase-U position detection signal A, output from a position detecting section 22, varies; during interrupt handling, it computes an position detection time interval Ta based on two variations in the phase-U position detection signal A; when the position detection time interval Ta is shorter than a reference time a1, it determines that the cause of the variations in the phase-U position detection signal A is noise and terminates the interrupt handling; it computes a position detection time interval Tab based on variation in the phase-U position detection signal and variation in a phase-V position detection signal B; when the position detection time interval Tab is within the range of a reference time, it detects the levels of phase-V and -W position detection signals B, C, different from the phase-U position detection signal A; and then, based thereon, it determines an energization pattern for an energization signal. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a brushless motor control method, a brushless motor control device, and a brushless motor device, and more particularly, to generate a plurality of phase position detection signals based on terminal voltages generated in each of a plurality of stator windings. The present invention relates to a sensorless brushless motor control method, a brushless motor control device, and a brushless motor device.

  As a method for controlling this type of brushless motor, there is the following technique (see, for example, Patent Document 1). For example, in the example described in Patent Document 1, when supplying DC power to an armature winding of a brushless motor via an inverter circuit, the control circuit uses a position detection signal from a position detection unit to The position is detected, and the transistor of the inverter circuit is driven on and off based on the position detection.

  In addition, the control circuit calculates the time of the rotor position detection interval, and when this calculation interval time is not within the predetermined range, does not generate a signal for driving the inverter circuit as an error in the position detection system, Stop operation. When a predetermined time has elapsed from the stop of the operation, the operation is started again. When the position detection interval time after the start of the re-operation is not within the predetermined range, the operation is stopped because the position detection system is abnormal, and the operation is not restarted. It is possible.

On the other hand, when the position detection interval is within a predetermined range within a predetermined time from the start of the re-operation, the re-operation is continued, and the abnormality determination operation of the position detection system can be repeated.
JP-A-8-322282

  However, in the example described in Patent Document 1, when the rotational speed of the brushless motor is low or in a noisy environment, noise is generated near the intersection with the neutral point potential of the signal output from the integration circuit of the position detection unit. May occur. Therefore, in such a case, the comparison signal between the output signal from the integrating circuit and the neutral point potential changes at a shorter interval than that at the time of position detection.

  In the example described in Patent Document 1, when the comparison signal between the output signal from the integration circuit and the neutral point potential changes a plurality of times at shorter intervals than at the time of position detection, the interrupt processing based on the first signal change is performed. The time is detected, and the time of the position detection interval is calculated by the interrupt process based on the second signal change.

  At this time, if at least one of the first signal change and the second signal change is due to noise, the position detection interval time is calculated as a result of the interrupt processing based on the second signal change. Is determined to be outside the predetermined range, and the generation of the drive waveform is stopped.

  In the example described in Patent Document 1, the operation is resumed after a predetermined time elapses, and the interrupt process is performed every time the signal changes. Even when the change is based on the change, the generation of the drive waveform is stopped again, and a notification process indicating that it is determined to be abnormal is performed.

  As described above, in the example described in Patent Document 1, when noise occurs in the output signal from the integration circuit, there is a problem that the brushless motor stops due to the noise and malfunctions.

  Further, as described in Patent Document 1, if a predetermined time until restart of operation is determined by one timer function during interrupt processing, the microcomputer is occupied by the processing of this timer function, and the microcomputer is occupied. The processing speed of the computer is significantly reduced. Therefore, there is a possibility that the microcomputer cannot perform other processing.

  If the position detection interval time based on the position detection signal is outside the specified range, it is necessary to prevent a large current from flowing through a specific switching element of the inverter circuit and to prevent deterioration and damage of the switching element. There is.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a brushless motor capable of continuing the operation of the brushless motor without malfunction even when a signal change due to noise occurs in the position detection signal. A motor control method, a brushless motor control device, and a brushless motor device are provided.

  Another object of the present invention is to prevent a large current from flowing through a specific switching element of the inverter circuit unit when the position detection interval time based on the position detection signal is outside the predetermined reference time range. Another object of the present invention is to provide a brushless motor control method, a brushless motor control device, and a brushless motor device capable of preventing deterioration and damage of a switching element.

  Still another object of the present invention is to provide a brushless motor control method, a brushless motor control device, and a brushless motor device capable of preventing a reduction in processing speed of a control unit.

  In order to solve the above problem, the invention according to claim 1 generates a position detection signal of a plurality of phases based on a terminal voltage generated in each of a plurality of stator windings provided in a brushless motor, A brushless motor control method for controlling rotation of a brushless motor by sequentially switching energization to the stator winding by an energization signal generated based on the position detection signal, the same among the multiple phase position detection signals An interrupt process is performed for each change in phase position detection signal, and a position detection interval time is calculated based on at least two signal changes in the same phase position detection signal in the interrupt process. When the time is smaller than a predetermined reference time, it is determined that the change in the position detection signal is due to noise, and the interrupt process is terminated. It is characterized in.

  According to a seventh aspect of the present invention, there is provided a position detection unit for detecting a terminal voltage generated in each of a plurality of stator windings provided in a brushless motor and outputting a plurality of phase position detection signals; A control unit that generates and outputs an energization signal based on the position detection signal output from the detection unit, and an inverter circuit unit that sequentially switches energization to the stator winding based on the energization signal output from the control unit In the brushless motor control device configured to include the control unit, the control unit performs an interrupt process for each change in the position detection signal of the same phase output from the position detection unit, and in the interrupt process When the position detection interval time is calculated based on at least two signal changes in the position detection signal of the same phase, and the position detection interval time is shorter than a predetermined reference time Characterized in that the change of the position detection signal ends the interrupt processing determines to be due to noise.

  As described above, according to the first or seventh aspect of the invention, the interrupt process is performed every time the same-phase position detection signal among the plural-phase position detection signals changes, and the same-phase position detection is performed in this interrupt process. A position detection interval time is calculated based on at least two signal changes in the signal, and when the position detection interval time is smaller than a predetermined reference time, it is determined that the change in the position detection signal is due to noise. The interrupt process is terminated. Therefore, even when a signal change due to noise occurs in the position detection signal, the operation of the brushless motor can be continued without malfunction.

  In order to solve the above problem, the invention according to claim 2 generates a plurality of position detection signals based on terminal voltages generated in each of the plurality of stator windings provided in the brushless motor. And a brushless motor control method for controlling the rotation of the brushless motor by sequentially switching the energization to the stator windings by the energization signal generated based on the position detection signal, the method comprising: When the first position detection interval time is calculated based on at least two signal changes in the position detection signals of the same phase, and the first position detection interval time is longer than a predetermined reference time, the same At least one signal change in the phase position detection signal and at least one signal change in the phase position detection signal different from the same phase position detection signal. Then, the second position detection interval time is calculated, and when the second position detection interval time is outside the predetermined reference time range, it is determined that the position detection is abnormal and the output of the energization signal is stopped. It is characterized by doing.

  According to an eighth aspect of the present invention, there is provided a position detection unit that detects a terminal voltage generated in each of a plurality of stator windings provided in a brushless motor and outputs a plurality of position detection signals; A control unit that generates and outputs an energization signal based on the position detection signal output from the detection unit, and an inverter circuit unit that sequentially switches energization to the stator winding based on the energization signal output from the control unit In the brushless motor control device configured to include the first position detection interval based on at least two signal changes in the same-phase position detection signal output from the position detection unit. When the time is calculated and the first position detection interval time is larger than a predetermined reference time, at least one signal change in the same-phase position detection signal and the same A second position detection interval time is calculated based on at least one signal change in a position detection signal of a phase different from the position detection signal of the second position detection signal, and the second position detection interval time is a predetermined reference time range When it is outside, it is determined that the position detection is abnormal, and the output of the energization signal is stopped.

  Thus, in the invention according to claim 2 or claim 8, the first position detection interval time is calculated based on at least two signal changes in the position detection signal of the same phase among the position detection signals of the plurality of phases. Then, it is determined whether or not the change in the position detection signal is due to noise.

  If the first position detection interval time is larger than a predetermined reference time, that is, if the change in the position detection signal is not due to noise but due to rotor position detection, the same phase The second position detection interval time is calculated based on at least one signal change in the position detection signal and at least one signal change in the position detection signal in a phase different from the position detection signal in the same phase.

  At this time, if the calculation of the second position detection interval time is performed based on at least two signal changes in the same-phase position detection signal as in the prior art, the signal change due to noise is added to the same-phase position detection signal. If this occurs, the second position detection interval time cannot be accurately calculated.

  On the other hand, generally, even when a signal change due to noise occurs in the position detection signal of the same phase, no signal change due to noise occurs in the position detection signal of a phase different from the position detection signal of the same phase. Sometimes.

  Therefore, as in the present invention, based on at least one signal change in the position detection signal of the same phase and at least one signal change in the position detection signal of a phase different from the position detection signal of the same phase, the second When the position detection interval time is calculated, even when a plurality of signal changes due to noise occur in the position detection signal of the same phase, the first signal change of the position detection signal of the same phase is valid, and the second time Since it is ignored thereafter, the second position detection interval time can be calculated with high accuracy. As a result, even when a signal change due to noise occurs in the specific position detection signal, the operation of the brushless motor can be continued without malfunction.

  In the present invention, the second position detection interval time is calculated as described above, and when the second position detection interval time is outside the predetermined reference time range, it is determined that the position detection is abnormal. Stop the output of the energization signal. As a result, it is possible to prevent a large current from flowing through a specific switching element of the inverter circuit unit, and thus it is possible to prevent deterioration and damage of the switching element.

  At this time, as described in claim 3 or claim 9, when the second position detection interval time is outside a predetermined reference time range, it is determined that the position detection is abnormal and the output of the energization signal is performed. If the operation is stopped and the output of the energization signal is permitted after a predetermined time has elapsed, the brushless motor can be re-operated when the position detection abnormality is resolved.

  In addition, as described in claim 4 or claim 10, interrupt processing is performed every time the position detection signal of the same phase is changed, and whether or not a predetermined time has passed is determined for each interrupt processing. Then, since the passage of a predetermined time until the restart of operation is intermittently determined by a plurality of interruption processes, it is possible to prevent the control unit from being occupied by the processing of the timer function. As a result, it is possible to prevent a decrease in processing speed of the control unit.

  Furthermore, in the invention according to claim 5 or claim 11, when the second position detection interval time is within a predetermined reference time range and a predetermined time has elapsed, the position of the same phase is detected. The level of the at least two-phase position detection signal different from the detection signal is detected, and the energization pattern of the energization signal is determined based on the level of the at least two-phase position detection signal.

  At this time, if the level of the position detection signal of the same phase is detected and the energization pattern of the energization signal is determined based on this signal level, a signal change due to noise occurs in the position detection signal of the same phase In this case, the energization pattern of the energization signal cannot be accurately calculated.

  On the other hand, even when a signal change due to noise occurs in the position detection signal of the same phase, no signal change due to noise occurs in the position detection signal of at least two phases different from the position detection signal of the same phase. Sometimes.

  Therefore, as described above, the level of the position detection signal of at least two phases different from the position detection signal of the same phase is detected, and the energization pattern of the energization signal is determined based on the level of the position detection signal of at least two phases. By doing so, even when a signal change due to noise occurs in the position detection signal of the same phase, the brushless motor can be operated without malfunction.

  And, as described in claim 6 or claim 12, when the second position detection interval time is within a predetermined reference time range and after a predetermined time has elapsed, the position of the same phase When the level of at least two-phase position detection signals different from the detection signal is detected and the level of at least two-phase position detection signals is different from a predetermined level, it is determined that the position detection is abnormal, and If the output is stopped, it is possible to prevent a large current from flowing through a specific switching element of the inverter circuit unit, and thus it is possible to prevent deterioration and damage of the switching element.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. It should be noted that members, arrangements, and the like described below do not limit the present invention, and it goes without saying that various modifications can be made in accordance with the spirit of the present invention.

First, the configuration of a brushless motor device 10 according to an embodiment of the present invention will be described with reference to FIG.
A brushless motor device 10 according to an embodiment of the present invention shown in FIG. 1 is preferably used for a cooling device that cools a radiator of an engine provided in a vehicle (not shown). The controller 14 is configured as a control device.

  The brushless motor 12 includes a stator 16 that generates a driving magnetic field and a rotor 18 that rotates by the driving magnetic field generated from the stator 16. The stator 16 is provided with U-phase, V-phase, and W-phase stator windings 16U, 16V, and 16W connected in a Y-shape, and the rotor 18 includes a permanent magnet (reference numeral in FIG. 1). (Omitted) is provided.

  The controller 14 is supplied with power from the DC power supply device and drives the brushless motor 12, and is constituted by, for example, a one-chip electric circuit, a small control device, or the like. The controller 14 of this example includes an inverter circuit unit 20, a position detection unit 22, and a control unit 24.

  The inverter circuit unit 20 includes a so-called full-wave drive circuit in which an upper arm and a lower arm are bridge-connected. That is, the upper arm of the inverter circuit unit 20 is configured by the switching elements 26a to 26c and the diodes 28a to 28c, and the lower arm is configured of the switching elements 26d to 26f and the diodes 28d to 28f.

  The position detection unit 22 includes a pseudo induced voltage detection circuit 22A, a reference potential generation circuit 22B, and a position detection signal output circuit 22C. The pseudo-induced voltage detection circuit 22A is configured by a low-pass filter (integration circuit) including a resistor and a capacitor (not shown). The pseudo-induced voltage detection circuit 22A of this example integrates the terminal voltage signals U, V, and W of the stator windings 16U, 16V, and 16W, respectively, and pseudo-induces the U-phase, V-phase, and W-phase phases. The voltage signals U ′, V ′, and W ′ are generated and output to the position detection signal output circuit 22C.

  The position detection signal output circuit 22C includes a comparator corresponding to each of the U phase, the V phase, and the W phase. Each phase comparator receives the pseudo induced voltage signals U ′, V ′, W ′ output from the pseudo induced voltage detection circuit 22A and the reference voltage signal S generated by the reference potential generating circuit 22B. It has become so.

  Each phase comparator compares the pseudo induced voltage signals U ′, V ′, W ′ output from the pseudo induced voltage detection circuit 22A with the reference voltage signal S generated by the reference potential generating circuit 22B. Thus, a zero cross signal is generated and output as position detection signals A, B, and C to a phase correction circuit 30A of the control unit 24 described later.

  The control unit 24 includes a microcomputer 30 and a drive driver circuit 32. The microcomputer 30 includes a phase correction circuit 30A and an energization logic control circuit 30B. The phase correction circuit 30A is configured to output delay signals A ′, B ′, and C ′ obtained by delaying the phases of the position detection signals A, B, and C output from the position detection signal output circuit 22C until the commutation timing. Has been.

  The energization logic control circuit 30B performs a predetermined calculation based on a control signal output from an external controller (not shown) and energizes based on the delay signals A ′, B ′, and C ′ output from the phase correction circuit 30A. Configured to generate logic. Details of the processing by the microcomputer 30 will be described later.

  The drive driver circuit 32 generates six-phase energization signals Ha, Hb, Hc, La, Lb, and Lc based on the energization logic generated by the energization logic control circuit 30 </ b> B, and these are generated as switching elements of the inverter circuit unit 20. It is configured to output to the gates 26a to 26f.

  Next, the operation and effect of the brushless motor device 10 having the above configuration will be described.

  FIG. 2 is a flowchart showing the processing contents of the microcomputer 30 according to the present embodiment, and FIGS. 3 and 4 are diagrams showing signal waveforms output or detected from each unit of FIG.

  When a control signal output from an external controller (not shown) is input to the microcomputer 30, the microcomputer 30 causes the energization logic control circuit 30 </ b> B to perform energization logic based on a synchronization signal output from a synchronization signal output circuit (not illustrated). Is output to the drive driver circuit 32. The drive driver circuit 32 generates six-phase energization signals Ha, Hb, Hc, La, Lb, and Lc based on the energization logic generated by the energization logic control circuit 30 </ b> B, and these are generated as switching elements of the inverter circuit unit 20. Output to the gates 26a to 26f.

  When energization signals Ha, Hb, Hc, La, Lb, and Lc are input to the inverter circuit unit 20, the switching elements 26a to 26f are sequentially switched. When the switching elements 26a to 26f are sequentially switched, a current flows through the stator windings 16U, 16V, and 16W in a predetermined order. Among the stator windings 16U, 16V, and 16W, a fixed current that has flowed. A drive magnetic field is emitted from the child windings 16U, 16V, and 16W, and forced driving of the brushless motor 12 is started.

  Subsequently, the speed of the rotor 18 is increased by shortening the switching period of the synchronization signal. Then, the forced drive is switched to the sensorless drive in a state where the switching period of the synchronization signal becomes a predetermined value. That is, the control unit 24 generates energization signals Ha, Hb, Hc, La, Lb, and Lc based on the position detection signals A, B, and C output from the position detection unit 22, and thereby the rotor 18 is sensorless. Rotate by. At this time, the microcomputer 30 performs the interrupt process shown in FIG. 2 every time the U-phase position detection signal A changes.

(When position detection is performed normally)
In the interrupt process shown in FIG. 2, first, the change time ta2 (see FIG. 3) of the U-phase position detection signal A that triggered the current interrupt process is read (step S1). In the present embodiment, a count value of a timer J, which will be described later, is read as the change time ta2. Subsequently, the change time ta1 (see FIG. 3) stored in the previous interrupt process is read (step S2).

  Then, the position detection interval time Ta = ta2−ta1 is calculated from the change time ta2 of the U-phase position detection signal A that triggered the current interrupt process and the change time ta1 stored in the previous interrupt process ( Step S3).

  Subsequently, it is determined whether or not the position detection interval time Ta is larger than the reference time a1 (step S4). The reference time a1 is set to be slightly longer than the interval time of signal change due to noise, and is set to 500 μsec as an example in the present embodiment.

  If no signal change due to noise occurs in the U-phase position detection signal A and there is no abnormality in the rotational speed of the brushless motor 12, it is determined that the position detection interval time Ta is longer than the reference time a1. (Step S4: YES).

  Subsequently, the latest change time tb2 of the V-phase position detection signal B before the change time ta2 of the U-phase position detection signal A that triggered the current interruption process is read (step S5).

  Then, from the change time ta2 of the U-phase position detection signal A that triggered the current interruption process and the change time tb2 of the latest V-phase position detection signal B before the change time ta2, The position detection interval time Tab = ta2-tb2 is calculated (step S6).

  Subsequently, whether or not the position detection interval time Tab with the other phase is within a predetermined reference time range, that is, the position detection interval time Tab with the other phase is larger than the reference time ab1 and more than the reference time ab2. Is also smaller (step S7).

  In the present embodiment, since the 120-degree energization method is employed, the position detection interval time Tab with the other phase is equivalent to an electrical angle of 60 °. Therefore, in the present embodiment, the reference time ab1 is set to an electrical angle of 30 ° so that the position detection abnormality (rotation speed abnormality) occurs when the rotation speed of the brushless motor 12 exceeds twice or less than 1/2. Correspondingly, the reference time ab2 is determined to correspond to an electrical angle of 120 °.

  At this time, if the calculation of the position detection interval Tab is performed based on at least two signal changes in the U-phase position detection signal A as in the prior art, the U-phase position detection signal A as shown in FIG. If the signal changes due to noise, the position detection interval time Tab cannot be accurately calculated.

  On the other hand, generally, even when a signal change due to noise occurs in the U-phase position detection signal A, no signal change due to noise occurs in the V-phase position detection signal B as shown in FIG. Sometimes.

  Therefore, as in the present embodiment, the position detection with the other phase is detected from the change time ta2 of the U-phase position detection signal A and the change time tb2 of the latest V-phase position detection signal B before the change time ta2. When the interval time Tab = ta2-tb2 is calculated, the first signal change of the U-phase position detection signal A is valid even if a plurality of signal changes due to noise occur in the U-phase position detection signal A. Since the second and subsequent times are ignored, the position detection interval time Tab can be calculated with high accuracy. Thereby, even when a signal change due to noise occurs in a specific position detection signal (in this embodiment, a U-phase position detection signal A), the operation of the brushless motor 12 can be continued without malfunction.

  If it is determined that the position detection interval time Tab with the other phase is within a predetermined reference time range (step S7: YES), is the position detection abnormality flag in the microcomputer 30 set? It is determined whether or not (step S11).

  The position detection abnormality flag is set when it is determined in step S7 or step S14 that a position detection abnormality has occurred, as will be described in detail later. Therefore, when the position detection is normally performed, it is determined that the position detection abnormality flag in the microcomputer 30 is not set (step S11: NO).

  Subsequently, the levels of the V-phase position detection signal B and the W-phase position detection signal C are detected (step S12). Then, it is determined whether or not the level of the V-phase position detection signal B is H and the level of the W-phase position detection signal C is L (step S13).

  At this time, if it is determined that the level of the V-phase position detection signal B is H and the level of the W-phase position detection signal C is L (step S13: YES), the U-phase position detection signal A Since the change time is equivalent to ta1, the energization signals Ha, Hb, Hc, La, Lb, and Lc are set in the energization pattern 4 (see FIG. 3) for the next time (after delay) (step S17).

  Subsequently, phase correction is performed on the energization pattern set in step S17, and energization switching time is set (step S18). That is, the delay amount α (phase correction amount) is added to ta1 shown in FIG. 3 to set the timer J, and the timer J is started. When the timer J reaches this set value, a separately prepared interrupt program for the timer J is executed, and switching of the energization pattern is started.

  On the other hand, when it is determined that the level of the V-phase position detection signal B is H and the level of the W-phase position detection signal C is not L (step S13: NO), the level of the V-phase position detection signal B is At L, it is determined whether or not the level of the W-phase position detection signal C is H (step S14).

  When it is determined that the level of the V-phase position detection signal B is L and the level of the W-phase position detection signal C is H (step S14: YES), the change of the U-phase position detection signal A is changed. Since the time is ta2, the energization signals Ha, Hb, Hc, La, Lb, and Lc are set to the next energization pattern 1 (see FIG. 3) (step S19).

  Subsequently, phase correction is performed on the energization pattern set in step S19, and energization switching time is set (step S20). Here, the delay amount α (phase correction amount) is added to ta2 shown in FIG. 3 to set the timer J, and the timer J is started. When the timer J reaches this set value, a separately prepared interrupt program for the timer J is executed, and switching of the energization pattern is started.

  Then, the change time ta2 of the U-phase position detection signal A that triggered the current interrupt process is stored as ta1 (step S24), and the series of interrupt processes ends. Thereafter, the microcomputer 30 performs the above interrupt processing every time the U-phase position detection signal A changes. Thereby, the operation of the brushless motor 12 is continued.

(When a signal change due to noise occurs in the position detection signal)
On the other hand, in the process of step S4 described above, a signal change due to noise occurs in the U-phase position detection signal A along with the noise fluctuation generated in the U-phase pseudo-induced voltage signal U ′ as shown in FIG. In the case (see the change time ta1 or ta2 in FIG. 4), the position detection interval time Ta is determined to be equal to or shorter than the reference time a1 (step S4: NO).

  In this embodiment, in this case, it is determined that the change (oscillation) of the position detection signal A at the change time ta1 or ta2 in FIG. 4 is due to noise (after the brushless motor device 10 is started up, the U phase Even if a signal change due to noise occurs in the position detection signal A, the first signal change is regarded as normal, and the process up to step S24 for storing the change time ta1 is performed, and the position detection interval time Ta < Since it is a1, it is determined that it is due to noise). If it is determined that the noise is detected, the interrupt processing is terminated without performing any processing.

  That is, in the present embodiment, for the oscillation of the position detection signal A at the change time ta1 or ta2 shown in FIG. 4, the first signal change is enabled and the second signal change is ignored. . Therefore, by ignoring the second signal change, interrupt processing due to noise is not performed.

  In this way, even when signal changes due to noise occur in the position detection signals A, B, and C, the operation of the brushless motor 12 can be continued without malfunction.

  Even if the second signal change is due to normal position detection, and the first signal change is due to noise and deviates from the normal position detection time, this first signal change oscillation interval Therefore, even if the first signal change is made valid and the second signal change is ignored as described above, it can be said that there is almost no influence on the position detection accuracy.

(When an abnormality occurs in position detection)
If it is determined in step S7 that the position detection interval Tab with the other phase is outside the predetermined reference time range (step S7: NO), it is determined that the position detection is abnormal. The output of the energization signals Ha, Hb, Hc, La, Lb, Lc is stopped (step S8).

  At this time, the fact that the position detection interval Tab with the other phase is equal to or less than the reference time ab1 means that the rotational speed of the brushless motor 12 has suddenly increased. This means that the rotor of the brushless motor 12 is driven greatly from the outside. Since it cannot occur unless force is applied, in this embodiment, it is determined to be abnormal.

  Further, even when a waveform disturbance occurs in the pseudo-induced voltage signal U ′ due to the motor lock, or when a waveform disturbance occurs in the pseudo-induced voltage signal U ′ due to a sudden change in the power supply voltage, the position relative to the other phase is also detected. It is conceivable that the detection interval time Tab is equal to or less than the reference time ab1, and in this case as well, it is determined that there is an abnormality in this embodiment.

  Thus, in the present embodiment, the position detection interval time Tab is calculated, and when the position detection interval time Tab is outside the predetermined reference time range, it is determined that the position detection is abnormal and the energization signals Ha, The output of Hb, Hc, La, Lb, Lc is stopped. Thereby, since it is possible to prevent a large current from flowing through the specific switching elements 26a to 26f of the inverter circuit unit 20, it is possible to prevent deterioration and damage of the switching elements 26a to 26f.

  In step S8, it is determined that the position detection is abnormal, and after the output of the energization signals Ha, Hb, Hc, La, Lb, Lc is stopped, a position detection abnormality flag in the microcomputer 30 is set (step S9), and a timer is set. K is started (step S10). As will be described in detail later, the timer K is for maintaining the energization-off state in step S8 for a predetermined time ΔT.

  Then, after starting the timer K as described above, the change time ta2 of the U-phase position detection signal A that triggered the current interrupt process is stored as ta1 (step S24), and the series of interrupt processes ends. To do. Thereafter, the microcomputer 30 performs the above interrupt processing every time the U-phase position detection signal A changes.

(Re-operation after abnormal stop)
On the other hand, even if the output of the energization signals Ha, Hb, Hc, La, Lb, and Lc is stopped in step S8 described above, the rotor of the brushless motor 12 continues to rotate with inertia. Also in this case, the U-phase position detection signal A changes, and the above interrupt processing is performed every time the position detection signal A changes. At this time, if the motor lock is not generated in the brushless motor 12, an accurate position detection signal A is obtained.

  If it is determined in the process of step S7 that the position detection interval time Tab with the other phase is within a predetermined reference time range (step S7: YES), a position detection error in the microcomputer 30 is detected. It is determined whether or not a flag is set (step S11).

  Here, since the position detection abnormality flag is set in the process of step S9 described above, it is determined that the position detection abnormality flag is set (step S11: YES). Subsequently, it is determined whether or not the count value of the timer K is larger than a predetermined time ΔT (step S15).

  When it is determined that the count value of the timer K is equal to or less than the predetermined time ΔT (step S15: NO), the change time ta2 of the U-phase position detection signal A that triggered the current interruption process is set to ta1. (Step S24), and a series of interrupt processing ends. Thereafter, the microcomputer 30 performs the above interrupt processing every time the U-phase position detection signal A changes.

  Thus, in the present embodiment, when the rotor of the brushless motor 12 continues to rotate due to inertia, the position detection is normally performed and the position detection interval time Tab with the other phase is determined in advance. Even if it is within the range, no processing is performed within the period in which the output of the energization signals Ha, Hb, Hc, La, Lb, and Lc is stopped because there is an abnormality in position detection in step S8. Without interrupting.

  This interruption process is repeated until it is determined in step S15 that the count value of the timer K is greater than the predetermined time ΔT. Thus, in the present embodiment, it is determined whether or not the predetermined time ΔT has elapsed in step S15 for each interrupt process.

  In this embodiment, the energization signals Ha, Hb, Hc, La, Lb, and Lc are repeated by repeating the interrupt process until it is determined in step S15 that the count value of the timer K is greater than the predetermined time ΔT. The period in which the output is stopped is a preparation period for restarting the brushless motor 12.

  On the other hand, if the count value of the timer K exceeds the predetermined time ΔT by repeatedly performing the above interrupt processing, it is determined in step S15 that the count value of the timer K is greater than the predetermined time ΔT (step S15: YES) In this case, the position detection abnormality flag set in the process of step S9 is cleared in order to permit the output of the energization signals Ha, Hb, Hc, La, Lb, and Lc (step S16). As a result, the brushless motor 12 can be re-operated.

  As described above, in this embodiment, since the passage of the predetermined time ΔT until the restart of operation is intermittently determined by a plurality of interrupt processes, the microcomputer 30 is occupied by the process of the timer function. Can be prevented. Thereby, it is possible to prevent the processing speed of the microcomputer 30 from being lowered.

  Then, after clearing the position detection abnormality flag in step S16, the processing of step S12, step S13, step S17, and step S18 is performed in the same manner as described above, or step S12 to step S14, step S19, step. The process of S20 is performed. Thereby, the operation of the brushless motor 12 is smoothly resumed.

  Subsequently, the change time ta2 of the U-phase position detection signal A that triggers the current interrupt processing is stored as ta1 (step S24), and the series of interrupt processing ends. Thereafter, the microcomputer 30 performs the above interrupt processing every time the U-phase position detection signal A changes. Thereby, the operation of the brushless motor 12 is continued.

  As described above, in this embodiment, the level of the V-phase position detection signal B and the level of the W-phase position detection signal C that are different from the U-phase position detection signal A are detected, and the position of the V-phase is detected. Based on the level of the detection signal B and the level of the W-phase position detection signal C, the energization patterns of the energization signals Ha, Hb, Hc, La, Lb, and Lc are determined.

  At this time, the level of the U-phase position detection signal A is detected, and the energization patterns of the energization signals Ha, Hb, Hc, La, Lb, and Lc are determined based on this signal level, as shown in FIG. Thus, when a signal change due to noise occurs in the U-phase position detection signal A, the energization patterns of the energization signals Ha, Hb, Hc, La, Lb, and Lc cannot be accurately calculated.

  On the other hand, as shown in FIG. 4, even if a signal change due to noise occurs in the U-phase position detection signal A, the V-phase position detection signal B and the W-phase position detection signal C are caused by noise. There may be no signal change.

  Therefore, as described above, the level of the V-phase position detection signal B and the level of the W-phase position detection signal C different from the U-phase position detection signal A are detected, and the level of the V-phase position detection signal B is detected. When the energization patterns of the energization signals Ha, Hb, Hc, La, Lb, and Lc are determined based on the level of the W-phase position detection signal C and the U-phase position detection signal C, as shown in FIG. Even when a signal change due to noise occurs in A, the brushless motor 12 can be operated without malfunction.

(If an abnormality occurs in position detection during re-operation after an abnormal stop)
On the other hand, if the level of the V-phase position detection signal B is L and the level of the W-phase position detection signal C is not H (NO in step S14) in the process of step S14 described above, it is determined that the position detection is abnormal. Then, the output of the energization signals Ha, Hb, Hc, La, Lb, Lc is stopped (step S21).

  As described above, in the present embodiment, when the position detection interval time Tab is within a predetermined reference time range and after a predetermined time ΔT has elapsed, V is different from the U-phase position detection signal A. The level of the position detection signal B of the phase and the level of the position detection signal C of the W phase are detected, and the level of the position detection signal B of the V phase and the level of the position detection signal C of the W phase are different from the predetermined levels. In this case, it is determined that the position detection is abnormal, and output of the energization signals Ha, Hb, Hc, La, Lb, and Lc is stopped.

  Thereby, since it is possible to prevent a large current from flowing through the specific switching elements 26a to 26f of the inverter circuit unit 20, it is possible to prevent deterioration and damage of the switching elements 26a to 26f.

  Then, a position detection abnormality flag in the microcomputer 30 is set (step S22), and the timer K is started (step S23). Subsequently, after the timer K is started as described above, the change time ta2 of the U-phase position detection signal A that triggered the current interrupt process is stored as ta1 (step S24), and a series of interrupt processes are performed. finish. Thereafter, the microcomputer 30 performs the above interrupt processing every time the U-phase position detection signal A changes. This interruption process is repeated until it is determined in step S15 that the count value of the timer K is greater than the predetermined time ΔT.

  If the count value of the timer K exceeds the predetermined time ΔT by repeating the above interrupt processing, it is determined in step S15 that the count value of the timer K is larger than the predetermined time ΔT (step S15: YES). In this case, the position detection abnormality flag set in the process of step S9 described above is cleared to permit the output of the energization signals Ha, Hb, Hc, La, Lb, and Lc (step S16). As a result, the brushless motor 12 can be re-operated.

  Then, after clearing the position detection abnormality flag in step S16, the processing of step S12, step S13, step S17, and step S18 is performed in the same manner as described above, or step S12 to step S14, step S19, step. The process of S20 is performed. Thereby, the operation of the brushless motor 12 is smoothly resumed.

It is a figure which shows the structure of the brushless motor apparatus which concerns on one Embodiment of this invention. It is a flowchart which shows the processing content of the microcomputer which concerns on one Embodiment of this invention. It is a figure which shows the signal waveform output or detected from each part of FIG. It is a figure which shows the signal waveform output or detected from each part of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Brushless motor apparatus, 12 ... Brushless motor, 14 ... Controller (control apparatus), 16 ... Stator, 16U, 16V, 16W ... Stator winding, 18 ... Rotation 20 ... inverter circuit unit, 22 ... position detection unit, 22A ... pseudo-induced voltage detection circuit, 22B ... reference potential generation circuit, 22C ... position detection signal output circuit, 24 ... Control unit, 26a, 26b, 26c, 26d, 26e, 26f ... switching element, 28a, 28b, 28c, 28d, 28e, 28f ... diode, 30 ... microcomputer, 30A ... phase correction Circuit, 30B... Energization logic control circuit, 32... Drive driver circuit

Claims (13)

A plurality of phase position detection signals are generated based on terminal voltages generated in each of the plurality of phase stator windings provided in the brushless motor, and the stator windings are generated by energization signals generated based on the position detection signals. A brushless motor control method for controlling the rotation of the brushless motor by sequentially switching energization to
An interrupt process is performed for each change in the same phase position detection signal among the multiple phase position detection signals, and a position detection interval time is set based on at least two signal changes in the same phase position detection signal in the interrupt process. A brushless motor that calculates and determines that the change of the position detection signal is due to noise when the position detection interval time is smaller than a predetermined reference time, and ends the interrupt process. Control method. A plurality of phase position detection signals are generated based on terminal voltages generated in each of the plurality of phase stator windings provided in the brushless motor, and the stator windings are generated by energization signals generated based on the position detection signals. A brushless motor control method for controlling the rotation of the brushless motor by sequentially switching energization to
A first position detection interval time is calculated based on at least two signal changes in the same phase position detection signal among the plurality of phase detection signals, and the first position detection interval time is a predetermined reference time. The second position based on at least one signal change in the position detection signal of the same phase and at least one signal change in the position detection signal of a phase different from the position detection signal of the same phase. A detection interval time is calculated, and when the second position detection interval time is out of a predetermined reference time range, it is determined that the position detection is abnormal, and the output of the energization signal is stopped. Brushless motor control method.   When the second position detection interval time is outside a predetermined reference time range, it is determined that the position detection is abnormal, and the output of the energization signal is stopped, and the output of the energization signal is permitted after a predetermined time has elapsed. The method of controlling a brushless motor according to claim 2.   4. The method of controlling a brushless motor according to claim 3, wherein an interrupt process is performed for each change in the position detection signal of the same phase, and it is determined whether the predetermined time has elapsed for each interrupt process. 5. .   When the second position detection interval time is within a predetermined reference time range and after the predetermined time has elapsed, at least two phase position detection signals different from the same phase position detection signal 5. The brushless motor control method according to claim 3, wherein an energization pattern of the energization signal is determined based on a level of the at least two-phase position detection signal.   When the second position detection interval time is within a predetermined reference time range and after the predetermined time has elapsed, at least two phase position detection signals different from the same phase position detection signal When the level of the at least two-phase position detection signal is different from a predetermined level, it is determined that the position detection is abnormal and the output of the energization signal is stopped. The method for controlling a brushless motor according to any one of claims 3 to 5. A position detection unit that detects a terminal voltage generated in each of a plurality of stator windings provided in the brushless motor and outputs a position detection signal of a plurality of phases;
A control unit that generates and outputs an energization signal based on the position detection signal output from the position detection unit;
An inverter circuit section for sequentially switching energization to the stator winding based on the energization signal output from the control section;
In a control device for a brushless motor configured with
The control unit performs an interrupt process for each change in the same-phase position detection signal output from the position detection unit, and performs a position based on at least two signal changes in the same-phase position detection signal in the interrupt process. A detection interval time is calculated, and when the position detection interval time is smaller than a predetermined reference time, it is determined that the change in the position detection signal is due to noise, and the interrupt process is terminated. A control device for a brushless motor. A position detection unit that detects a terminal voltage generated in each of a plurality of stator windings provided in the brushless motor and outputs a position detection signal of a plurality of phases;
A control unit that generates and outputs an energization signal based on the position detection signal output from the position detection unit;
An inverter circuit section for sequentially switching energization to the stator winding based on the energization signal output from the control section;
In a control device for a brushless motor configured with
The control unit calculates a first position detection interval time based on at least two signal changes in the same-phase position detection signal output from the position detection unit, and determines the first position detection interval time in advance. Based on at least one signal change in the same phase position detection signal and at least one signal change in a position detection signal in a phase different from the same phase position detection signal. The second position detection interval time is calculated, and when the second position detection interval time is outside the predetermined reference time range, it is determined that the position detection is abnormal and the output of the energization signal is stopped. A control device for a brushless motor characterized by the above.   When the second position detection interval time is outside a predetermined reference time range, the control unit determines that the position detection is abnormal and stops outputting the energization signal, and the energization is performed after a predetermined time has elapsed. 9. The brushless motor control device according to claim 8, wherein output of the signal is permitted.   The control unit performs an interrupt process for each change in the same-phase position detection signal output from the position detection unit, and determines whether the predetermined time has elapsed for each interrupt process. The brushless motor control device according to claim 9.   When the second position detection interval time is within a predetermined reference time range and after the predetermined time has elapsed, the control unit is at least two different from the same-phase position detection signal. The brushless motor according to claim 9 or 10, wherein a level of a phase position detection signal is detected, and an energization pattern of the energization signal is determined based on the level of the at least two phase position detection signals. Control device.   When the second position detection interval time is within a predetermined reference time range and after the predetermined time has elapsed, the control unit is at least two different from the same-phase position detection signal. Detecting the level of the phase position detection signal, and if the level of the position detection signal of at least two phases is different from a predetermined level, determining that the position detection is abnormal and stopping the output of the energization signal. The brushless motor control device according to any one of claims 9 to 11, wherein the brushless motor control device is a control device. In a brushless motor device comprising a control device for controlling a brushless motor,
A brushless motor device using the brushless motor control device according to any one of claims 7 to 12 as the control device.

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