JP2015033191A - Motor controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor controller which allows for acceleration up to high speed in feedback control mode, while preventing malfunction.SOLUTION: A motor controller includes a motor having a rotor, and a plurality of position detecting sections for detecting the rotational position of the rotor, and control means for setting a delay angle based on the output from any one of the plurality of position detecting sections. The control means selects any one of the plurality of position detecting sections based on a delay angle change amount, i.e., the difference between a target delay angle and a current delay angle, and sets a delay angle by using the output from a position detecting section thus selected.

Description

  The present invention relates to a motor control device, and more particularly to a motor control device capable of driving in a feedback control mode.

  The stepping motor has features such as small size, high torque, and long life, and can easily perform digital positioning control by open loop control. For this reason, it is widely used in optical devices such as cameras, interchangeable lenses, and printers.

  However, the stepping motor has a problem that the motor steps out when there is a heavy load or when high-speed rotation is attempted. Therefore, the stepping motor is attached with an encoder that detects the rotational position of the rotor, and the same operation as a so-called brushless DC motor that switches the energization state of the coil according to the rotational position of the rotor is performed to prevent step-out. A method has been proposed.

  Here, the drive mode by the open loop control of the stepping motor is called an open loop control mode, and the drive mode by the same control as the brushless DC motor is called a feedback control mode.

  For example, Patent Document 1 discloses a control method in which an advance angle is set based on the edge of a rotor sensor, and commutation delay of a drive signal is compensated according to the set value.

Japanese Patent Registration No. 042020317

  In Patent Document 1, since which drive signal commutates at which sensor edge is determined in advance, when accelerating, the delay angle approaches 0, and it is impossible to accelerate further. End up. In addition, if it is attempted to accelerate forcibly in this state, a malfunction such as step-out may occur.

  In view of such a problem, an object of the present invention is to provide a motor control device that can accelerate to a high speed in the feedback control mode and prevent malfunction.

  A motor control device according to one aspect of the present invention is a motor including a rotor, a plurality of position detection units that detect a rotational position of the rotor, and any one position among the plurality of position detection units. Control means for setting a delay angle based on an output of the detection unit, the control means from the plurality of position detection unit based on a delay angle change amount which is a difference between the target delay angle and the current delay angle One of the position detection units is selected, and a delay angle is set using an output of the selected position detection unit.

  According to another aspect of the present invention, there is provided a motor control method comprising: a rotor; and a plurality of position detection units that detect rotational positions of the rotor. A delay angle is set based on the output of any one of the position detection units, and the setting step includes a delay angle change amount that is a difference between the target delay angle and the current delay angle. Based on the above, one of the plurality of position detection units is selected, and the delay angle is set using the output of the selected position detection unit.

  According to the present invention, it is possible to provide a motor control device that can accelerate to a high speed in the feedback control mode and prevent malfunction.

1 is a perspective view of a motor according to an embodiment of the present invention. It is sectional drawing of a motor. It is a block diagram of a motor control device. It is a figure which shows the sequence of the whole control. It is a signal waveform diagram showing the transition from the open loop control mode to the feedback control mode. It is a signal waveform diagram showing switching of the Hall element signal in the acceleration control in the conventional feedback control mode. FIG. 6 is a signal waveform diagram showing switching of the Hall element signal in the acceleration control in the feedback control mode of the first embodiment. 3 is a flowchart of acceleration control in a feedback control mode according to the first embodiment. It is a signal waveform diagram showing switching of the Hall element signal in the deceleration control of the conventional feedback control mode. FIG. 6 is a signal waveform diagram showing switching of the hall element signal in the deceleration control in the feedback control mode of the first embodiment. 3 is a flowchart of deceleration control in a feedback control mode according to the first embodiment. It is a signal waveform diagram showing switching of the Hall element signal in the acceleration control in the feedback control mode of the second embodiment. 6 is a flowchart of acceleration control in a feedback control mode according to the second embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same members are denoted by the same reference numerals, and redundant description is omitted.

(About motor structure)
FIG. 1 is a perspective view of a motor according to an embodiment of the present invention. For the sake of explanation, some parts are shown broken.

  The motor 101 includes a rotor 103 having a magnet 102, a first coil 104a, a second coil 104b, a first yoke 105a, a second yoke 105b, and a magnetic sensor 106. Among these, the first coil 104a, the second coil 104b, the first yoke 105a, the second yoke 105b, and the magnetic sensor 106 constitute a stator.

  The magnet 102 is a cylindrical permanent magnet whose outer periphery is magnetized in the circumferential direction with multiple poles (n poles). The magnet 102 forms a magnetic flux pattern in which the strength of the magnetic force changes in a sine wave shape with respect to the rotation direction around the rotation axis of the rotor 103. In this embodiment, n = 8 is magnetized, but the present invention is not limited to this configuration.

  The rotor 103 is rotatably supported with respect to the stator and is fixed integrally with the magnet 102.

  The first coil 104a and the second coil 104b are each configured by winding a conducting wire around a bobbin (not shown) many times around the rotation center of the rotor 102 as an axis.

  The first yoke 105a has a plurality of magnetic pole teeth excited by the first coil 104a. The torque applied to the rotor 103 can be changed by switching the poles to be excited. Similarly, the second yoke 105b has a plurality of exciting teeth magnetically poled by the second coil 104b, and the torque applied to the rotor 103 can be changed by switching the excited poles.

The magnetic sensor 106 is a non-contact type magnetic detection unit that detects the magnetic flux of the magnet 102 such as a Hall element. The magnetic sensor 106 includes a first magnetic pole (first position detector) 106a and a second magnetic pole (second position detector) 106b (not shown in FIG. 1). The first and second magnetic poles 106 a and 106 b detect the rotational position of the rotor 102 by detecting a change in the magnetic field accompanying the rotation of the magnet 102. The magnetic sensor 106 has two output terminals, and outputs a voltage according to the magnetic flux density penetrating each magnetic pole. A positive voltage is output when the magnet facing the sensitive magnetic pole is an N pole, and a negative voltage is output when the facing magnet is an S pole. The output of the magnetic sensor 106 is a binarized output, and a High signal is output for the N pole and a Low signal is output for the S pole. In the present embodiment, digital control is performed based on these values. However, when the magnetic sensor 106 is an analog output sensor and outputs a magnetic force in the form of a sine wave, the motor may be controlled by analog control based on the output signal.
(About the phase relationship of Hall element signals)
FIG. 2 is a cross-sectional view of the motor 101 taken along a plane perpendicular to the rotor 103 and passing through each magnetic pole of the magnetic sensor 106. For simplification of the drawing, only the positional relationship between the magnetic sensor 106 and the first and second magnetic poles 106a and 106b, the first yoke 105a, and the second yoke 105b is shown.

  The first sensitive magnetic pole 106a is disposed at a position 22.5 ° away from the second sensitive magnetic pole 106b in the rotational direction θ of the rotor in terms of physical angle. The magnetic pole teeth of the second yoke 105b exist at a position 67.5 ° away from the first sensitive magnetic pole 106a in the θ direction, and further away from the second yoke 105b by 22.5 ° in the same direction (θ direction). The magnetic pole teeth of the first yoke 105a exist at the position.

In this embodiment, since the magnet 102 is magnetized to eight poles, the angle 22.5 ° in the physical rotor rotation direction corresponds to 90 ° when converted to an electrical angle where one wavelength of the sensor output is 360 °. In FIG. 2, only the magnetic pole teeth of the pair of first and second yokes 105a and 105b are shown as an example. However, the magnetic pole teeth of the first and second yokes 105a and 105b are each 90 ° in physical angle (electrical There are four each at every 360 ° in angle).
(About motor control device)
FIG. 3 is a block diagram of the motor control device, showing a configuration for performing feedback control.

  The arithmetic device 301 includes a signal measurement processing unit 302, a delay angle setting unit 303, and a drive signal generation unit (signal generation unit) 307.

  The signal measurement processing unit 302 receives the binarized signal output of the magnetic sensor 106 of the motor 101. The signal measurement processing unit 302 acquires a timer count value for each change in polarity of the Hall element signal, and acquires a cycle from the current value and the previous value. However, when the output of the magnetic sensor 106 is analog, a binarization circuit is provided between the motor 101 and the arithmetic unit 301 to send a binarization signal to the signal measurement processing unit 302.

  Similarly to the Hall element signal, measurement of the drive signal output from the drive signal generation unit 307 also acquires a timer count value for each polarity change of the drive signal, and acquires a cycle from the current value and the previous value.

  From the two Hall element signals and the timer count value of the driving signal, the delay angle setting unit 303 determines the delay angle. The delay angle here refers to a delay amount of the drive signal with reference to a change in polarity of the Hall element signal. The delay angle may be handled as time data or as data converted into an electrical angle. In the present embodiment, description will be made as data converted into an electrical angle.

  The delay angle setting unit 303 includes a delay angle operation unit 304, a reference signal selection unit 305, and a reference signal switching determination unit 306. The delay angle operation unit 304 increases or decreases the delay angle, and the reference signal selection unit 305 selects a Hall element that serves as a reference for generating a drive signal. Further, the reference signal switching determination unit 306 determines whether to switch from one Hall element signal currently selected as the reference signal to the other Hall element signal.

  Based on the delay angle set by the delay angle setting unit 303, a drive signal is sent from the drive signal generation unit 307 to the motor driver (drive unit) 308 to switch excitation of the motor 101.

Note that the motor control device according to the present embodiment is used in various optical devices such as a lens drive of a lens device that can be attached to and detached from an imaging device of a camera system.
(About motor control method)
The motor 101 can be driven in an open loop control mode or a feedback control mode.

  Driving in the open loop control mode is the same as the open loop control of a normal stepping motor, and is a control method for switching the polarity of energizing each coil of the motor 101 according to a predetermined time interval. That is, the rotor 103 can be rotated at a predetermined speed by sequentially switching the energization of each coil in accordance with the input drive pulse interval (drive frequency) and the rotation direction. Further, the rotor 103 can be rotated by a desired angle in accordance with the input drive pulse number. This driving method is an open loop control mode performed in this embodiment.

In the feedback control mode, the drive means the polarity of energizing each coil according to the input drive pulse number and rotation direction, and the delay angle determined by the delay angle setting unit 303 from the Hall element signal and the timer count value of the drive signal. This is a control method for sequentially switching. That is, in contrast to the open loop control mode in which the pulse signal of a predetermined reference frequency is driven as a reference, the feedback control mode is a drive mode that generates and generates a drive signal based on the polarity change of the signal output from the Hall element. The drive signal is a delay signal with respect to the Hall element signal. In the present embodiment, one drive signal is generated for one Hall element signal, but the present invention is not limited to this form. This driving method is a feedback control mode performed in this embodiment. In the feedback control mode, the coil energization is switched based on the position of the rotor, so that occurrence of step-out due to a response delay of the rotor can be reduced, and high-speed driving is possible.
(About motor drive sequence)
FIG. 4 is a diagram showing a sequence of the entire control. Specifically, it shows the overall drive speed from drive start to acceleration drive, constant speed drive, deceleration drive, and drive stop, transition of drive mode, and switching of Hall element signals.

First, acceleration driving is started for the stopped motor in the open loop control mode, and when the predetermined rotational speed is reached, the mode is shifted to the feedback control mode. During the feedback control mode, the target maximum speed is reached while switching the Hall element signal serving as a reference signal for generating a drive signal as necessary. Then, after driving at a constant speed so as to maintain the target speed, the operation shifts to deceleration driving, and similarly to acceleration driving, deceleration driving is performed to the open loop control mode switching point while switching the Hall element signal as necessary. Then, the mode again shifts from the feedback control mode to the open loop control mode, and stops when the number of input drive pulses is reached. The above is an overall control flow from the start to the stop of driving.
(Transition from open loop control mode to feedback control mode)
Transition from the open loop control mode to the feedback control mode during acceleration after the start of driving will be described with reference to FIG. FIG. 5 shows waveforms of the Hall element signal and the drive signal when shifting from the open loop control mode to the feedback control mode during driving in the forward rotation direction (θ direction in FIG. 2). The four waveforms are signals input to the signal measurement processing unit 302. The Hall element signal of the Hall element 106b is H1, the Hall element signal of the Hall element 106a is H2, the positive side of the drive signal used for switching the excitation of the first coil 104a is A +, and the excitation switching of the second coil 104b is used. The + side of the drive signal to be generated is B +.

  While driving the motor 101 in the open loop control mode, the signal measurement processing unit 302 acquires delay angles for the two Hall element signals each time the polarity of the A-phase drive signal and the B-phase drive signal changes. That is, at the falling edge 501 of the A phase, the delay angle T1 with respect to the rising edge of the Hall element signal H1 and the delay angle T2 with respect to the rising edge of the Hall element signal H2 are acquired. Similarly, at the rising edge 502 of the B phase, the delay angle T3 with respect to the rising edge of the hall element signal H2 and the delay angle T4 with respect to the falling edge of the hall element signal H1 when not shown are obtained. These delay angles are acquired and updated every time the energization is switched, that is, every time the polarity of the drive signal changes, regardless of the open loop control mode or the feedback control mode.

  In the present embodiment, when shifting from the open loop control mode to the feedback control mode, the magnitudes of the delay angles with respect to the Hall element signals H1 and H2 immediately before the transition are compared, and the smaller Hall element signal is used as a reference signal for driving signal generation. To do. Also, the delay angle immediately before switching is set as the initial delay angle in the feedback control mode. The reason why the Hall element signal with the smaller delay angle is selected as the reference signal is that when the smaller delay angle is selected, the influence of the phase shift of the drive signal due to the detection error of the magnetic sensor can be suppressed. is there.

  In FIG. 5, the Hall element signal H1 is used as a reference signal for generating the A-phase drive signal from the delay angle T2> the delay angle T1, and the polarity change (falling in the figure) of the Hall element signal H1 after the shift to the feedback control mode. Thus, the phase A is set so as to be generated (rise in the figure) at the delay angle T1. Similarly, the Hall element signal H2 is used as a reference signal for generating the B phase drive signal, and the B phase is generated (falling in the figure) at a delay angle T3 with respect to the polarity change (rising in the figure) of the Hall element signal H2. Set to. Thus, by using the value immediately before the open loop control mode as the initial delay angle value, smooth mode transition can be realized even if there are individual differences in the motor 101 and variations in detection of the magnetic sensor 106.

  In this embodiment, the delay angle immediately before the open loop control mode is used as the initial delay angle value in the feedback control mode, but the value obtained by subtracting the predetermined angle from the delay angle immediately before switching is used. The initial delay angle may be used.

Further, in the present embodiment, when the predetermined period is reached during driving in the open loop control mode, the mode shifts from the open loop control mode to the feedback control mode, but the present invention is not limited to this.
(Feedback control mode acceleration method)
Next, acceleration control after shifting to the feedback control mode will be described.

  When accelerating in the feedback control mode, the delay angle operation unit 304 sets a value obtained by subtracting the delay angle change amount ΔT from the delay angle of the drive signal with respect to the change in polarity of the Hall element signal as a new delay angle (target delay angle). Generate a drive signal. That is, the acceleration control is performed by increasing the timing of switching the polarity of the drive signal when switching the energization to the coil. In this embodiment, the delay angle change amount ΔT is considered not by time but by electrical angle. The electrical angle can be obtained by (delay time ÷ hall element period × 360). The reason for considering the electrical angle rather than the time is that if the predetermined time is subtracted, the proportion of the predetermined time in the delay angle increases as the speed increases, and the acceleration cannot be made constant.

  For example, when the A-phase drive signal is generated with a delay angle of 30 ° with respect to the Hall element signal H1, if the predetermined angle for acceleration is 1 °, the next A-phase drive signal is the Hall element signal It is generated with a delay angle of 29 ° with respect to H1.

  The acceleration timing may be performed every time the energization is switched to the coil, may be performed every predetermined period, or may be changed according to the difference between the target speed and the current speed.

  However, when the acceleration is continued and the delay angle operation is advanced, the delay angle gradually decreases and eventually the delay angle becomes 0 °. In order to further accelerate, theoretically, it is necessary to set a minus value (generate an A-phase drive signal before the edge of the reference Hall element signal H1). If it becomes negative, the A-phase drive signal is generated based on the Hall element signal H1, so that the algorithm breaks down and acceleration control becomes impossible. This state will be described with reference to FIG.

  FIG. 6 is a signal waveform diagram showing switching of the Hall element signal in the acceleration control in the conventional feedback control mode. In FIG. 6, for simplification of description, the B-phase drive signal is omitted, and only the A-phase drive signal is described.

  Before the Hall element replacement, the A-phase drive signal is generated with a delay angle T61 delayed with respect to the Hall element signal H1. However, when the delay angle is converted into time and becomes smaller than a predetermined value THmin (for example, 50 μs), as shown in FIG. 6A, the reference signal is switched to the Hall element signal H2, and the Hall element signal H2 is used as a reference. A drive signal is generated with a delay of the delay angle T62. The reason why the predetermined value for switching the Hall element is converted to time is to generate the drive signal based on the Hall element that is as close to the speed as possible. The reason for using the Hall element close to the drive signal as a reference is as described in the section (Transition from the open loop control mode to the feedback control mode).

  When the motor 101 is slowly accelerated (for example, by 1 °), the above-described method can be used. However, when the motor 101 is to be accelerated rapidly (for example, by 10 °), the above-described Hall element replacement method may fail. is there.

  For example, the case where the motor 101 is driven at 1800 PPS (two-phase drive) and the predetermined value THmin is 50 μs will be described with reference to FIG. 50 μs corresponds to about 8 ° in electrical angle in 1800 PPS. When the delay angle T63 is 60 μs in terms of time, the Hall element is not replaced because it is smaller than the predetermined value THmin. Here, when an acceleration command with a target advance angle of 10 ° is issued at the falling timing of the Hall element signal H1, subtracting 10 ° from the delay angle results in a negative value. If a negative value is set in the delay angle operation unit 304, drive signal generation at an appropriate timing will fail. Therefore, the motor 101 decelerates rapidly, rotates in the direction opposite to the current direction, or steps out.

  In order to prevent these phenomena, the acceleration method in this embodiment will be described with reference to FIGS. FIG. 7 is a signal waveform diagram showing switching of the Hall element signal in the acceleration control in the feedback control mode. T in FIG. 7 represents a time axis. FIG. 8 is a flowchart of the acceleration control in the feedback control mode. The acceleration control in FIG. 8 is performed for each polarity change of each Hall element signal.

  Consider a case where an acceleration command with a target advance angle of 10 ° is issued at time t2 (during the fall processing of the Hall element signal H1) in FIG.

  Acceleration control is started in the feedback control mode (S801, S is an abbreviation for step), and it is determined whether the Hall element replacement flag is set to 1 (S802). The hall element replacement flag is a flag that becomes 1 when the hall element needs to be replaced, and the initial value is 0. If the Hall element replacement flag is set to 1, the process proceeds to S803, and if it is cleared to 0, the process proceeds to S805. Since it is cleared to 0 this time, the process proceeds to S805.

  In S805, it is determined whether or not the acceleration flag is set to 1. The acceleration flag is a flag for accelerating by reducing the delay angle. In this embodiment, the acceleration is performed once every several times. However, the acceleration may be performed for every change in the polarity of the Hall element, or may be performed for each specific timing with a timer or the like. If the acceleration flag is set to 1, the process proceeds to S806, and if it is cleared to 0, the process proceeds to S811. At time t2, since the acceleration flag is set to 1, the process proceeds to S806. If the acceleration flag is cleared to 0, in S811, the previous delay angle is set to the current delay angle, and the acceleration processing routine is terminated (S812).

  In S806, the previous delay angle is compared with the acceleration angle of 10 °. The previous delay angle in this case is the delay angle T71 when the Hall element signal H1 generates the A-phase drive signal at time t1. If the delay angle is larger, the process proceeds to S807, and if the acceleration angle is larger, the process proceeds to S809. In FIG. 7, since delay angle T71 <acceleration angle 10 °, the process proceeds to S809.

  In S809, since the acceleration angle cannot be subtracted larger than the delay angle T71 at time t1, the delay angle set this time is set to the same value as the previous delay angle T71. Since it is set to the same value as the previous delay angle, it cannot be accelerated at time t2. When the setting is completed, the process proceeds to S810.

  In S810, since the required Hall element for generating the drive signal cannot be accelerated as it is, the process of changing the reference Hall element is performed. The changing process is performed by setting the Hall element replacement flag to 1. One Hall element replacement flag is provided for each of the A-phase drive signal and the B-phase drive signal. If the flag is set to 1, the acceleration processing routine is terminated (S812).

  At time t3 (during the rise processing of the hall element signal H2), acceleration control in the feedback control mode is started (S801), and it is determined whether the hall element exchange flag is set to 1 (S802). Since the Hall element replacement flag of the A phase drive signal is set to 1 this time, the process proceeds to S803.

  In S803, the reference Hall element is replaced. The reference Hall element is replaced by setting the previous delay angle of the replaced Hall element and drive signal to the previous delay angle. That is, the previous delay angle is set to the Hall element signal H2 after replacement and the delay angle T72 of the A-phase drive signal. When the setting is completed, the Hall element replacement flag is cleared to 0 (S804).

  In S805, it is determined whether or not the acceleration flag is set to 1. Since it has been set to 1 since the falling processing of the Hall element signal H1 at time t2, the process proceeds to S806.

  In S806, the previous delay angle is compared with the acceleration angle of 10 °. Since the previous delay angle is the delay angle T72 between the Hall element signal H2 and the A-phase drive signal in S803, T72 is compared with an acceleration angle of 10 °. Since the delay angle T72 is larger than the acceleration angle 10 °, the process proceeds to S807.

  In S807, in order to perform acceleration processing, a value (T72-10 °) obtained by subtracting the acceleration angle (10 °) from the previous delay angle (T72) is set as the current delay angle. After acceleration, the acceleration flag is cleared to 0 in S808, and the acceleration processing routine is terminated (S812).

In this embodiment, when acceleration control is performed in the feedback control mode, the previous delay angle is compared with the acceleration angle before acceleration, and when the acceleration angle is larger, a drive signal is generated with the same delay angle as the previous time. . Thereafter, the reference Hall element is replaced, and acceleration is performed after the replacement. Therefore, even when acceleration is performed, failure to generate a drive signal can be prevented, and step-out or the like can be prevented. In this way, the motor 101 can be accelerated to the target speed.
(About feedback control mode deceleration method)
Next, deceleration control will be described.

  When decelerating in the feedback control mode, the delay angle operation unit 304 sets a value obtained by adding the delay angle change amount ΔT to the delay angle of the drive signal with respect to the change in polarity of the Hall element signal as a new delay angle, and generates a drive signal. To do. That is, the deceleration control is performed by delaying the timing of switching the polarity of the drive signal when switching the energization to the coil. The delay angle change amount ΔT is considered as an electrical angle as in acceleration.

  For example, when the A-phase drive signal is generated with a delay angle of 30 ° with respect to the Hall element signal H1, if the predetermined angle for deceleration is 1 °, the next A-phase drive signal is the Hall element signal It is generated with a delay angle of 31 ° with respect to H1.

  The timing of deceleration may be performed every time the energization is switched to the coil, may be performed every predetermined period, or may be changed according to the difference between the target speed and the current speed.

  However, if the delay angle operation is continued while decelerating, the delay angle gradually increases, and the other Hall element is closer to the drive signal than the reference Hall element that generates the drive signal. . This state will be described with reference to FIG.

  FIG. 9 is a signal waveform diagram showing switching of the Hall element signal in the deceleration control in the conventional feedback control mode. In FIG. 9, for simplification of explanation, the B phase drive signal is omitted, and only the A phase drive signal is described.

  FIG. 9A shows a state in which the A-phase drive signal is generated based on the Hall element signal H1. When the delay angle T91 is gradually increased in order to decelerate, the state eventually becomes a broken line, and a Hall element with a smaller delay angle is selected when the A-phase drive signal is generated based on the Hall element signal H2. The detection error can be reduced. Therefore, it is necessary to replace the reference Hall element as in acceleration.

  In FIG. 9B, before the Hall element replacement, the A-phase drive signal is generated with a delay angle T92 delayed with respect to the Hall element signal H1. However, when the delay angle T93 is converted into time and becomes larger than a predetermined value THmin (for example, 50 μs), the reference signal is switched to the Hall element signal H2, and the drive signal is generated by delaying the delay element T93 with respect to the Hall element signal H2. To do.

  When the motor 101 is slowly decelerated (for example, by 1 °), there is no problem with the above-described method, but when it is desired to decelerate rapidly (for example, by 30 °), the above-described Hall element replacement method may fail. is there.

  For example, the case where the motor 101 is driven at 15000 PPS (two-phase drive) and the predetermined value THmin is 50 μs will be described with reference to FIG. 50 μs corresponds to an electrical angle of about 68 ° at 15000 PPS. When the delay angle T94 is 45 μs in terms of time, the Hall element is not replaced because it is smaller than the predetermined value THmin. Here, when a deceleration command with a target advance angle of 30 ° is issued at the falling timing of the Hall element signal H1, if the delay angle T94 is added 30 °, the set delay angle exceeds 180 °. If the set delay angle exceeds 180 °, the polarity of the Hall element signal H1 is changed again before the A-phase drive signal is generated at the set timing, and the delay angle is set again by 180 ° by the polarity change. Therefore, the A-phase drive signal is not generated forever. When such a phenomenon occurs, the motor 101 will step out.

  In order to prevent these phenomena, the deceleration method in this embodiment will be described with reference to FIGS. FIG. 10 is a signal waveform diagram showing switching of the Hall element signal in the deceleration control in the feedback control mode. T in FIG. 10 represents a time axis. FIG. 11 is a flowchart of the deceleration control in the feedback control mode. The deceleration control in FIG. 11 is performed for each polarity change of each Hall element signal.

  Consider a case in which a deceleration command with a target advance angle of 30 ° is issued at time t5 (during the fall processing of the Hall element signal H1) in FIG.

  Deceleration control in the feedback control mode is started (S1101), and it is determined whether the Hall element replacement flag is set to 1 (S1102). If the Hall element replacement flag is set to 1, the process proceeds to S1103, and if it is cleared to 0, the process proceeds to S1105. Since it is cleared to 0 this time, the process proceeds to S1105.

  In S1105, it is determined whether the deceleration flag is set to 1. The deceleration flag is a flag for increasing the delay angle and decelerating. In this embodiment, the deceleration is performed once every several times, but may be performed every time the polarity of the Hall element is changed, or may be performed every specific timing with a timer or the like. If the deceleration flag is set to 1, the process proceeds to S1106, and if it is cleared to 0, the process proceeds to S1110. At time t5, since the deceleration flag is set to 1, the process proceeds to S1106. If the deceleration flag is cleared to 0, in S1110, the previous delay angle is set to the current delay angle, and the deceleration processing routine is terminated (S812).

  In S1106, the value obtained by adding the deceleration angle 30 ° to the previous delay angle is compared with 180 ° (half cycle). The previous delay angle in this case is the delay angle T101 when the Hall element signal H1 generates the A-phase drive signal at time t4. If (previous delay angle + deceleration angle) is smaller than 180 °, the process proceeds to S1107, and if 180 ° is larger, the process proceeds to S1109. In FIG. 10, since (delay angle T101 + deceleration angle 30 °)> 180 °, the process proceeds to S1109.

  In S1109, if the deceleration angle is added to the previous delay angle, the angle exceeds 180 °, and the A-phase drive signal cannot be generated. Processing to change the Hall element is performed. The changing process is performed by setting the Hall element replacement flag to 1. One Hall element replacement flag is provided for each of the A-phase drive signal and the B-phase drive signal. If the flag is set to 1, the deceleration processing routine is terminated (S1111).

  At time t6 (during the rise processing of the Hall element signal H2), deceleration control in the feedback control mode is started (S1101), and it is determined whether the Hall element replacement flag is set to 1 (S1102). Since the Hall element replacement flag of the A phase drive signal is set to 1 this time, the process proceeds to S1103.

  In S1103, the reference Hall element is replaced. The reference Hall element is replaced by setting the previous delay angle of the replaced Hall element and drive signal as the previous delay angle. That is, the previous delay angle is set to the Hall element signal H2 after replacement and the delay angle T102 of the A-phase drive signal. When the setting is completed, the Hall element replacement flag is cleared to 0 (S1104).

  In S1105, it is determined whether the deceleration flag is set to 1. Since it has been set to 1 since the falling processing of the Hall element signal H1 at time t5, the process proceeds to S1106.

  In S1106, the value obtained by adding the deceleration angle 30 ° to the previous delay angle is compared with 180 °. Since the previous delay angle is the delay angle T102 of the Hall element signal H2 and the A-phase drive signal in S1103, (delay angle T102 + deceleration angle 30 °) is compared with 180 °. Since (delay angle T102 + deceleration angle 30 °) is smaller than 180 °, the process proceeds to S1107.

  In S1107, in order to perform deceleration processing, a value (T102 + 30 °) obtained by adding the deceleration angle (30 °) to the previous delay angle (T102) is set as the current delay angle. After deceleration, the deceleration flag is cleared to 0 in S1108, and the deceleration processing routine ends (S1111).

  In this embodiment, when deceleration control is performed in the feedback control mode, the value obtained by adding the previous delay angle and deceleration angle is compared with 180 ° before deceleration, and a drive signal is generated when 180 ° is smaller. After that, the reference Hall element is replaced, and the speed is reduced after the replacement. Therefore, even when sudden deceleration is performed, a drive signal generation failure can be prevented, and step-out and the like can be prevented. In this way, the motor 101 can be decelerated to the target speed.

  As described above, in the first embodiment, when accelerating in the feedback control mode, the delay angle and the acceleration angle are compared. If the acceleration angle is larger, the acceleration is not performed this time, and the acceleration is performed after the Hall element replacement. By doing so, it is possible to accelerate to a high speed in the feedback control mode and to prevent malfunctions such as step-out.

  Also, when decelerating, (delay angle + deceleration angle) is compared with 180 °, and if 180 ° is smaller, this time, it does not decelerate, it can decelerate to the target speed by decelerating after replacing the Hall element, and It is possible to prevent malfunction such as step-out.

  In the present embodiment, the delay angle setting method at the time of Hall element replacement in acceleration control is changed from the setting method of the first embodiment. Since the motor and configuration of this embodiment are the same as those of the first embodiment, description thereof is omitted.

  Hereinafter, the acceleration method of the present embodiment will be described with reference to FIGS. FIG. 12 is a signal waveform diagram showing switching of the Hall element signal in the acceleration control in the feedback control mode. T in FIG. 12 represents a time axis. FIG. 13 is a flowchart of the acceleration control in the feedback control mode. The acceleration control in FIG. 13 is performed for each polarity change of each Hall element signal. In addition, about the same element as FIG. 7 and FIG. 8 which were demonstrated in Example 1, the same code | symbol as Example 1 is attached | subjected and it replaces with description.

  Consider a case where an acceleration command with a target advance angle of 10 ° is issued at time t8 (at the time of falling processing of the Hall element signal H1) in FIG.

  In S806, the previous delay angle T71 is compared with the acceleration angle 10 °. Here, as in the first embodiment, since the previous delay angle T71 is set to be smaller, the process proceeds to S1301.

  In S1301, the current delay angle is set to Tmin. Tmin is the minimum delay time that can be set. This value is a value that is determined in consideration of the time taken from entering the Hall element polarity change processing routine until the delay angle is actually set. This value can be a value that has been measured in advance, or a value obtained by measuring the time to delay angle setting with a timer each time the Hall element polarity change processing routine is added, and adding the margin value to the measured value. It is good.

  In S1302, the remaining acceleration angle is calculated. The remaining acceleration angle is a value obtained by subtracting an angle that can be accelerated this time from an angle for which acceleration is requested (= 10 °). The angle that can be accelerated this time can be obtained by (time conversion of previous delay angle T71−Tmin) / period of Hall element signal H1 × 360 °.

  In S1303, the acceleration is performed to the limit with the current output out of the required acceleration angle of 10 °. Therefore, when the delay angle is set next time, only the remaining acceleration angle obtained in S1302 is accelerated. Therefore, since it is necessary to change the currently requested acceleration angle of 10 °, the acceleration angle change request flag is set to 1.

  In S812, the acceleration processing routine is terminated.

  At time t9 (during the rise processing of the Hall element signal H2), acceleration control in the feedback control mode is started (S801).

  In S806, since the previous delay angle is set to T122 in the Hall element replacement in S803, the acceleration angle becomes larger than 10 °, and the process proceeds to S1304.

  In S1304, it is determined whether or not the acceleration change flag is set to 1. If it is set to 1, the process proceeds to S1305, and if it is cleared to 0, the process proceeds to S807. The processing when it is cleared to 0 is the same as that in the first embodiment. Since this time is set to 1, the process proceeds to S1305.

  In S1305, the delay angle to be output this time is set. Here, in order to accelerate the amount that could not be accelerated at time t8, the remaining acceleration angle obtained in S1302 is subtracted from the previous delay angle T122.

  In S1306, since the acceleration angle change is completed, the acceleration angle change request flag is cleared to zero.

  In S812, the acceleration processing routine is changed.

  As described above, in the present embodiment, when the feedback control mode is accelerated, the delay angle and the acceleration angle are compared. I do. By doing so, it is possible to accelerate to a high speed in the feedback control mode and to prevent malfunctions such as step-out.

  In this embodiment, even when it is determined that the current reference Hall element cannot be accelerated, the acceleration is performed to the limit, so that the acceleration can be performed faster than in the first embodiment.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

101 Motor 103 Rotors 106a and 106b Position detection sensors (first and second position detection units)
304 Delay angle operation unit 305 Reference signal selection unit (selection unit)
306 Reference signal switching determination unit (determination unit)
307 Drive signal generator (signal generator)
308 Motor driver (drive unit)

Claims (9)

A motor comprising: a rotor; and a plurality of position detection units that detect a rotational position of the rotor;
Control means for setting a delay angle based on the output of any one of the plurality of position detection units,
The control means selects one position detection unit from the plurality of position detection units based on a delay angle change amount that is a difference between the target delay angle and the current delay angle, and the selected position detection unit A motor control device characterized in that a delay angle is set using the output of the motor.   The motor control apparatus according to claim 1, wherein the plurality of position detection units are arranged at predetermined intervals in a circumferential direction of the rotor. When accelerating control of the motor, if the current delay angle is smaller than the delay angle change amount,
The said control means sets the said target delay angle by the output of the position detection part different from the position detection part used when setting the said present delay angle. Motor control device. When accelerating control of the motor, if the current delay angle is smaller than the delay angle change amount,
The control means sets the delay angle that can be set by the output of the position detection unit used when setting the current delay angle, and then uses the position detection unit used when setting the current delay angle The motor control device according to claim 1, wherein the target delay angle is set based on an output of a position detection unit different from that of the motor. When the motor is decelerated and controlled, a value obtained by adding the delay angle change amount to the current delay angle corresponds to a half cycle of the output of the position detection unit used when setting the current delay angle. If larger than electrical angle,
The said control means sets the said target delay angle by the output of the position detection part different from the position detection part used when setting the said present delay angle. Motor control device. The motor is controlled by either a mode that is controlled by an open loop or a feedback control mode that is controlled by using the first and second position detectors,
The said control means sets a delay angle using the output of the said position detection part, when the said motor is controlled by the feedback control mode, The any one of Claim 1 thru | or 5 characterized by the above-mentioned. Motor control device.   A lens device comprising the motor control device according to claim 1. A lens device according to claim 7;
A camera system comprising: an imaging device to which the lens device can be attached and detached. A method for controlling a motor, comprising: a rotor; and a plurality of position detection units that detect a rotational position of the rotor,
Setting a delay angle based on the output of any one of the plurality of position detectors, and
The setting step selects one position detection unit from the plurality of position detection units based on a delay angle change amount that is a difference between the target delay angle and the current delay angle, and the selected position detection A control method for a motor, characterized in that a delay angle is set using an output of a unit.